Science.gov

Sample records for actively perform designated

  1. Large-scale performance and design for construction activity erosion control best management practices.

    PubMed

    Faucette, L B; Scholl, B; Beighley, R E; Governo, J

    2009-01-01

    The National Pollutant Discharge Elimination System (NPDES) Phase II requires construction activities to have erosion and sediment control best management practices (BMPs) designed and installed for site storm water management. Although BMPs are specified on storm water pollution prevention plans (SWPPPs) as part of the construction general permit (GP), there is little evidence in the research literature as to how BMPs perform or should be designed. The objectives of this study were to: (i) comparatively evaluate the performance of common construction activity erosion control BMPs under a standardized test method, (ii) evaluate the performance of compost erosion control blanket thickness, (iii) evaluate the performance of compost erosion control blankets (CECBs) on a variety of slope angles, and (iv) determine Universal Soil Loss Equation (USLE) cover management factors (C factors) for these BMPs to assist site designers and engineers. Twenty-three erosion control BMPs were evaluated using American Society of Testing and Materials (ASTM) D-6459, standard test method for determination of ECB performance in protecting hill slopes from rainfall induced erosion, on 4:1 (H:V), 3:1, and 2:1 slopes. Soil loss reduction for treatments exposed to 5 cm of rainfall on a 2:1 slope ranged from-7 to 99%. For rainfall exposure of 10 cm, treatment soil loss reduction ranged from 8 to 99%. The 2.5 and 5 cm CECBs significantly reduced erosion on slopes up to 2:1, while CECBs < 2.5 cm are not recommended on slopes >or= 4:1 when rainfall totals reach 5 cm. Based on the soil loss results, USLE C factors ranged from 0.01 to 0.9. These performance and design criteria should aid site planners and designers in decision-making processes. PMID:19398523

  2. Large-scale performance and design for construction activity erosion control best management practices.

    PubMed

    Faucette, L B; Scholl, B; Beighley, R E; Governo, J

    2009-01-01

    The National Pollutant Discharge Elimination System (NPDES) Phase II requires construction activities to have erosion and sediment control best management practices (BMPs) designed and installed for site storm water management. Although BMPs are specified on storm water pollution prevention plans (SWPPPs) as part of the construction general permit (GP), there is little evidence in the research literature as to how BMPs perform or should be designed. The objectives of this study were to: (i) comparatively evaluate the performance of common construction activity erosion control BMPs under a standardized test method, (ii) evaluate the performance of compost erosion control blanket thickness, (iii) evaluate the performance of compost erosion control blankets (CECBs) on a variety of slope angles, and (iv) determine Universal Soil Loss Equation (USLE) cover management factors (C factors) for these BMPs to assist site designers and engineers. Twenty-three erosion control BMPs were evaluated using American Society of Testing and Materials (ASTM) D-6459, standard test method for determination of ECB performance in protecting hill slopes from rainfall induced erosion, on 4:1 (H:V), 3:1, and 2:1 slopes. Soil loss reduction for treatments exposed to 5 cm of rainfall on a 2:1 slope ranged from-7 to 99%. For rainfall exposure of 10 cm, treatment soil loss reduction ranged from 8 to 99%. The 2.5 and 5 cm CECBs significantly reduced erosion on slopes up to 2:1, while CECBs < 2.5 cm are not recommended on slopes >or= 4:1 when rainfall totals reach 5 cm. Based on the soil loss results, USLE C factors ranged from 0.01 to 0.9. These performance and design criteria should aid site planners and designers in decision-making processes.

  3. ACTIVE FILTER HARDWARE DESIGN & PERFORMANCE FOR THE DIII-D PLASMA CONTROL SYSTEM

    SciTech Connect

    SELLERS,D; FERRON,J.R; WALKER,M.L; BROESCH,J.D

    2003-10-01

    OAK-B135 The digital plasma control system (PCS), currently in operation on the DIII-D tokamak, requires inputs from a large number of sensors. Due to the nature of the digitizers and the relative noisy environment from which these signals are derived, each of the 32 signals must be conditioned via an active filter. Two different types of filters, Chebyshev and Bessel with fixed frequencies: 100 Hz Bessel was used for filtering the motional Stark effect diagnostic data. 800 Hz Bessel was designed to filter plasma control data and 1200 Hz Chebyshev is used with closed loop control of choppers. The performance of the plasma control system is greatly influenced by how well the actual filter responses match the software model used in the control system algorithms. This paper addresses the various issues facing the designer in matching the electrical design with the theoretical.

  4. Evaluating the performance of close-range 3D active vision systems for industrial design applications

    NASA Astrophysics Data System (ADS)

    Beraldin, J.-Angelo; Gaiani, Marco

    2004-12-01

    In recent years, active three-dimensional (3D) active vision systems or range cameras for short have come out of research laboratories to find niche markets in application fields as diverse as industrial design, automotive manufacturing, geomatics, space exploration and cultural heritage to name a few. Many publications address different issues link to 3D sensing and processing but currently these technologies pose a number of challenges to many recent users, i.e., "what are they, how good are they and how do they compare?". The need to understand, test and integrate those range cameras with other technologies, e.g. photogrammetry, CAD, etc. is driven by the quest for optimal resolution, accuracy, speed and cost. Before investing, users want to be certain that a given range camera satisfy their operational requirements. The understanding of the basic theory and best practices associated with those cameras are in fact fundamental to fulfilling the requirements listed above in an optimal way. This paper addresses the evaluation of active 3D range cameras as part of a study to better understand and select one or a number of them to fulfill the needs of industrial design applications. In particular, object material and surface features effect, calibration and performance evaluation are discussed. Results are given for six different range cameras for close range applications.

  5. Evaluating the performance of close-range 3D active vision systems for industrial design applications

    NASA Astrophysics Data System (ADS)

    Beraldin, J.-Angelo; Gaiani, Marco

    2005-01-01

    In recent years, active three-dimensional (3D) active vision systems or range cameras for short have come out of research laboratories to find niche markets in application fields as diverse as industrial design, automotive manufacturing, geomatics, space exploration and cultural heritage to name a few. Many publications address different issues link to 3D sensing and processing but currently these technologies pose a number of challenges to many recent users, i.e., "what are they, how good are they and how do they compare?". The need to understand, test and integrate those range cameras with other technologies, e.g. photogrammetry, CAD, etc. is driven by the quest for optimal resolution, accuracy, speed and cost. Before investing, users want to be certain that a given range camera satisfy their operational requirements. The understanding of the basic theory and best practices associated with those cameras are in fact fundamental to fulfilling the requirements listed above in an optimal way. This paper addresses the evaluation of active 3D range cameras as part of a study to better understand and select one or a number of them to fulfill the needs of industrial design applications. In particular, object material and surface features effect, calibration and performance evaluation are discussed. Results are given for six different range cameras for close range applications.

  6. Instructional Design, Active Learning, and Student Performance: Using a Trading Room to Teach Strategy

    ERIC Educational Resources Information Center

    Stewart, Alice C.; Houghton, Susan M.; Rogers, Patrick R.

    2012-01-01

    This research used a quasi-experimental design with two conditions to test the impact of active learning in the context of integrated instructional design. The control condition was a traditional approach to teaching an undergraduate strategy capstone class. The intervention condition was an undergraduate strategy capstone class that was designed…

  7. Enabling People with Developmental Disabilities to Actively Follow Simple Instructions and Perform Designated Physical Activities According to Simple Instructions with Nintendo Wii Balance Boards by Controlling Environmental Stimulation

    ERIC Educational Resources Information Center

    Shih, Ching-Hsiang; Chung, Chiao-Chen; Shih, Ching-Tien; Chen, Ling-Che

    2011-01-01

    The latest researches have adopted software technology turning the Nintendo Wii Balance Board into a high performance standing location detector. This study extended Wii Balance Board functionality to assess whether two people with developmental disabilities would be able to actively perform designated physical activities according to simple…

  8. ZrO2 -Based Alternatives to Conventional Propane Dehydrogenation Catalysts: Active Sites, Design, and Performance.

    PubMed

    Otroshchenko, Tatyana; Sokolov, Sergey; Stoyanova, Mariana; Kondratenko, Vita A; Rodemerck, Uwe; Linke, David; Kondratenko, Evgenii V

    2015-12-21

    Non-oxidative dehydrogenation of propane to propene is an established large-scale process that, however, faces challenges, particularly in catalyst development; these are the toxicity of chromium compounds, high cost of platinum, and catalyst durability. Herein, we describe the design of unconventional catalysts based on bulk materials with a certain defect structure, for example, ZrO2 promoted with other metal oxides. Comprehensive characterization supports the hypothesis that coordinatively unsaturated Zr cations are the active sites for propane dehydrogenation. Their concentration can be adjusted by varying the kind of ZrO2 promoter and/or supporting tiny amounts of hydrogenation-active metal. Accordingly designed Cu(0.05 wt %)/ZrO2 -La2 O3 showed industrially relevant activity and durability over ca. 240 h on stream in a series of 60 dehydrogenation and oxidative regeneration cycles between 550 and 625 °C. PMID:26566072

  9. Performance-based design of active/hybrid protective systems for vibration reduction of buildings

    NASA Astrophysics Data System (ADS)

    Yang, Jann N.; Lin, Silian; Jabbari, Faryar

    2001-07-01

    In this paper, we present two control strategies for applications to civil engineering structures, referred to as the generalized H2 control and L1 control, respectively. Both control strategies are capable of addressing the performance-based design of structures, in the sense that the design requirements for the peak response quantities, such as peak interstory drifts, peak shear forces, peak floor accelerations, etc., can be satisfied. Likewise, these two controllers minimize the upper bound of the peak response of the controlled output vector. The design procedures for these two controllers are formulated in the framework of linear matrix inequalities (LMIs) so that the LMI toolbox in MATLAB can be used effectively and conveniently for the controller design. These control strategies are applied herein to the wind-excited benchmark problem to demonstrate their applicability to practical problems as well as their control performances. Simulation results illustrate that the performances of both the generalized H2 controller and the L1 controller are very plausible in comparison with the LQG control method.

  10. Innovative Research Design Exploring the Effects of Physical Activity and Genetics on Cognitive Performance in Community-Based Older Adults.

    PubMed

    Etnier, Jennifer L; Labban, Jeffrey D; Karper, William B; Wideman, Laurie; Piepmeier, Aaron T; Shih, Chia-Hao; Castellano, Michael; Williams, Lauren M; Park, Se-Yun; Henrich, Vincent C; Dudley, William N; Rulison, Kelli L

    2015-10-01

    Physical activity is predictive of better cognitive performance and lower risk of Alzheimer's disease (AD). The apolipoprotein E gene (APOE) is a susceptibility gene for AD with the e4 allele being associated with a greater risk of AD. Cross-sectional and prospective research shows that physical activity is predictive of better cognitive performance for those at greater genetic risk for AD. However, the moderating role of APOE on the effects of a physical activity intervention on cognitive performance has not been examined. The purpose of this manuscript is to justify the need for such research and to describe the design, methods, and recruitment tactics used in the conductance of a study designed to provide insight as to the extent to which cognitive benefits resulting from an 8-month physical activity program are differentiated by APOE e4 status. The effectiveness of the recruitment strategies and the feasibility of recruiting APOE e4 carriers are discussed.

  11. MSFC Skylab airlock module, volume 2. [systems design and performance, systems support activity, and reliability and safety programs

    NASA Technical Reports Server (NTRS)

    1974-01-01

    System design and performance of the Skylab Airlock Module and Payload Shroud are presented for the communication and caution and warning systems. Crew station and storage, crew trainers, experiments, ground support equipment, and system support activities are also reviewed. Other areas documented include the reliability and safety programs, test philosophy, engineering project management, and mission operations support.

  12. Assisting People with Disabilities in Actively Performing Designated Occupational Activities with Battery-Free Wireless Mice to Control Environmental Stimulation

    ERIC Educational Resources Information Center

    Shih, Ching-Hsiang

    2013-01-01

    The latest researches use software technology (OLDP, object location detection programs) to turn a commercial high-technology product, i.e. a battery-free wireless mouse, into a high performance/precise object location detector to detect whether or not an object has been placed in the designated location. The preferred environmental stimulation is…

  13. Design and performance of an ionisation chamber for the measurement of low alpha-activities

    NASA Astrophysics Data System (ADS)

    Hartmann, A.; Hutsch, J.; Krüger, F.; Sobiella, M.; Wilsenach, H.; Zuber, K.

    2016-04-01

    A new ionisation chamber for alpha-spectroscopy has been built from radio-pure materials for the purpose of investigating long lived alpha-decays. The measurement makes use of pulse shape analysis to discriminate between signal and background events. The design and performance of the chamber is described in this paper. A background rate of (10.9 ± 0.6) counts per day in the energy region of 1-9 MeV was achieved with a run period of 30.8 days. The background is dominantly produced by radon daughters.

  14. Enabling People with Developmental Disabilities to Actively Perform Designated Occupational Activities according to Simple Instructions with a Nintendo Wii Remote Controller by Controlling Environmental Stimulation

    ERIC Educational Resources Information Center

    Shih, Ching-Hsiang; Wang, Shu-Hui; Chang, Man-Ling; Shih, Ching-Hsiang

    2012-01-01

    The latest researches have adopted software technology, turning the Nintendo Wii Remote Controller into a high performance three-dimensional object orientation detector. This study extended Wii Remote Controller functionality to assess whether two people with developmental disabilities would be able to actively perform designated simple…

  15. Innovative Research Design Exploring the Effects of Physical Activity and Genetics on Cognitive Performance in Community-Based Older Adults

    PubMed Central

    Etnier, Jennifer L.; Labban, Jeffrey D.; Karper, William B.; Wideman, Laurie; Piepmeier, Aaron T.; Shih, Chia-Hao; Castellano, Michael; Williams, Lauren M.; Park, Se-Yun; Henrich, Vincent C.; Dudley, William N.; Rulison, Kelli L.

    2015-01-01

    Physical activity is predictive of better cognitive performance and lower risk of Alzheimer’s disease (AD). The apolipoprotein E gene (APOE) is a susceptibility gene for AD with the e4 allele being associated with a greater risk of AD. Cross-sectional and prospective research shows that physical activity is predictive of better cognitive performance for those at greater genetic risk for AD. However, the moderating role of APOE on the effects of a physical activity intervention on cognitive performance has not been examined. The purpose of this manuscript is to justify the need for such research and to describe the design, methods, and recruitment tactics used in the conductance of a study designed to provide insight as to the extent to which cognitive benefits resulting from an 8-month physical activity program are differentiated by ApoEe4 status. The effectiveness of the recruitment strategies and the feasibility of recruiting ApoE e4 carriers are discussed. PMID:25594264

  16. The design of an active-adaptive tuned vibration absorber based on magnetorheological elastomer and its vibration attenuation performance

    NASA Astrophysics Data System (ADS)

    Liao, G. J.; Gong, X. L.; Kang, C. J.; Xuan, S. H.

    2011-07-01

    This paper presents an active-adaptive tuned vibration absorber (AATVA) which is based on magnetorheological elastomer (MRE). A voice coil motor is attached to a conventional MRE adaptive tuned vibration absorber (ATVA) to improve its performance. In this study, two feedback types of the activation force were analyzed and the stability condition was obtained. In order to eliminate the time delay effect during the signal processing, a phase-lead compensator was incorporated. Based on the analysis, an MRE AATVA prototype was designed and its dynamic properties were experimentally investigated. The experimental results demonstrated that its resonant frequency could vary from 11 to 18 Hz and its damping ratio decreased to roughly 0.05 from 0.19 by adding the activation force. Besides, its vibration reduction abilities at the first two resonant frequencies of the experimental platform could reach 5.9 dB and 7.9 dB respectively.

  17. CHANG'E-3 Active Particle-induced X-ray Spectrometer: The synthesis design and performance

    NASA Astrophysics Data System (ADS)

    Cui, XingZhu; Peng, Wenxi; Wang, Huanyu; Liang, XiaoHua

    the Active Particle X-ray Spectrometer (APXS) was designed to deduce the elemental abundances of samples on the moon. Similar to the Alpha Particle X-ray Spectrometers onboard MSL and MER , the APXS was also an instrument took the advantage of X-ray fluorescence mechanism to determine elemental abundances, it determines the chemical compositions of both soil and rocks along the traverse of the rover. To provide a sound instrument working on the lunar surface,Four components were integrated in the APXS, the performances of the components were described in this paper.

  18. Probing Active Cocaine Vaccination Performance through Catalytic and Noncatalytic Hapten Design

    PubMed Central

    Cai, Xiaoqing; Whitfield, Timothy; Hixon, Mark S.; Grant, Yanabel; Koob, George F.; Janda, Kim D.

    2013-01-01

    Presently, there are no FDA-approved medications to treat cocaine addiction. Active vaccination has emerged as one approach to intervene through the rapid sequestering of the circulating drug, thus terminating both psychoactive effects and drug toxicity. Herein, we report our efforts examining two complimentary, but mechanistically distinct active vaccines, i.e., noncatalytic and catalytic, for cocaine treatment. A cocaine-like hapten GNE and a cocaine transition-state analogue GNT were used to generate the active vaccines, respectively. GNE-KLH was found to elicit persistent high-titer, cocaine-specific antibodies, and blunt cocaine induced locomotor behaviors. Catalytic antibodies induced by GNT-KLH were also shown to produce potent titers and suppress locomotor response in mice; however, upon repeated cocaine challenges the vaccine’s protecting effects waned. In depth kinetic analysis suggested that loss of catalytic activity was due to antibody modification by cocaine. The work provides new insights for the development of active vaccines for the treatment of cocaine abuse. PMID:23627877

  19. Design of a high-performance telepresence system incorporating an active vision system for enhanced visual perception of remote environments

    NASA Astrophysics Data System (ADS)

    Pretlove, John R. G.; Asbery, Richard

    1995-12-01

    This paper describes the design, development and implementation of a telepresence system for hazardous environment applications. Its primary feature is a high performance active stereo vision system slaved to the motion of the operators head. To simulate the presence of an operator in a remote, hazardous environment, it is necessary to provide sufficient visual information about the remote environment. The operator must be able to interact with the environment so that he can carry out manipulative tasks. To achieve an enhanced sense of visual perception we have developed a tightly integrated pan and tilt stereo vision system with a head-mounted display. The motion of the operators head is monitored by a six DOF sensor which provides the demand signals to servocontrol the active vision system. The system we have developed is a compact yet high performance system employing mechatronic principles to deliver a system that can be mounted on a small mobile platform. We have also developed an open architecture controller to implement the dynamic, active vision system which exhibits dynamic performance characteristics of the human head-eye system so as to form a natural and intuitive interface. A series of tests have been conducted to establish the system latency and to explore the effectiveness of remote 3D human perception, particularly with regard to manipulation tasks and navigation. The results of these tests are presented.

  20. Design and performance of a porous pot bioreactor for assessing biodegradation in activated sludge treatment

    SciTech Connect

    Nielsen, A.M.; McCormick, T.P.; Russell, G.L.; Filler, P.A.; Britton, L.N.

    1994-12-31

    It is useful to be able to predict biodegradation rates and extents of consumer chemicals in activated sludge (AS), municipal waste treatment units. This study describes an apparatus based on the porous pot concept developed in the United Kingdom. The benchtop apparatus is a single vessel and is constructed of glass that houses a porous, polypropylene ``candle`` to facilitate the control of the sludge retention time (SRT). Hydraulic retention time (HRT) in the fixed-volume vessel is controlled by the feed rate using low-volume pumps. At a typical volatile suspended solids concentration of 2,000 2,500 mg/L, the apparatus achieved 90--92% COD removal and 96--98% BOD removal from municipal sewage when operated at 6 hrs. HRT and 10 days SRT. Biodegradation of test compounds can be followed using specific analytical chemistry techniques or radiolabel recovery from {sup 14}C-substrates. {sup 14}C-benzene ring labelled linear alkyl benzene sulfonate (LAS) and four other radiolabeled surfactant compounds were used to determine the utility of the apparatus to follow biodegradation rates and extents in simulated AS treatment. Mineralization rates, as determined by {sup 14}CO{sub 2} trapping and measurement, were consistent during continuous operation, and total radiolabel recoveries ranged from 95--102% indicating excellent ability to follow the catabolic fate of test chemicals.

  1. Determining activated carbon performance

    SciTech Connect

    Naylor, W.F.; Rester, D.O.

    1995-07-01

    This article discusses the key elements involved in evaluating a system`s performance. Empty bed contact time (EBCT) is a term used to describe the length of time a liquid stream being treated is in contact with a granular activated carbon bed. The EBCT is the time required for a fluid to pass through the volume equivalent of the media bed, without the media being present. In a bed of granular activated carbon, the void volume or space between particles is usually about 45 percent. Therefore, the EBCT is about twice the true or actual time of contact between the fluid being treated and the GAC particles. The EBCT plays an important role in determining the effectiveness and longevity of granular activated carbon (GAC) used to treat liquids in a fixed-bed adsorber. Factors that influence and are influenced by EBCT, and their relationship to GAC performance in a treatment scheme include: adsorption, mass transfer zone, impurity concentration, adsorption affinity, flow rate and system design considerations.

  2. Design and performance of BNR activated sludge systems with flat sheet membranes for solid-liquid separation.

    PubMed

    du Toit, G J G; Ramphao, M C; Parco, V; Wentzel, M C; Ekama, G A

    2007-01-01

    The use of immersed membranes for solid-liquid separation in biological nutrient removal activated sludge (BNRAS) systems was investigated at lab scale. Two laboratory-scale BNR activated sludge systems were run in parallel, one a MBR system and the other a conventional system with secondary settling tanks. Both systems were in 3 reactor anaerobic, anoxic, aerobic UCT configurations. The systems were set up to have, as far as possible, identical design parameters such as reactor mass fractions, recycles and sludge age. Differences were the influent flow and total reactor volumes, and the higher reactor concentrations in the MBR system. The performances of the two systems were extensively monitored and compared to identify and quantify the influence of the membranes on system response. The MBR UCT system exhibited COD, FSA, TKN, TP and TSS removals that were consistently equivalent or superior to the conventional system. Better P removal in the MBR was attributed to lower observed P uptake in the anoxic zone. High nitrate loads to the anoxic reactor appeared to be the determining factor in stimulating P uptake. The MBR UCT system had a greater sludge production than the conventional system. This was partly attributable to the retention of all solids in the MBR reactor. For steady state design this increase is accommodated by increasing the influent unbiodegradable particulate COD fraction. Additionally an attempt was made to determine the Alpha values in the oxygen transfer rate. This paper briefly summarises and compares the results from both systems, and the conclusions that can be drawn from these results.

  3. Performance of a lead-scintillation-fiber calorimeter designed as an active beam shield for the VENUS detector

    NASA Astrophysics Data System (ADS)

    Takasaki, Fumihiko; Utsumi, M.; Fukui, T.; Narita, Y.; Hosoda, N.; Hirose, T.; Chiba, M.

    1992-11-01

    We made a cylindrical calorimeter which consisted of plastic scintillating fibers and lead. This calorimeter was designed to serve as an active beam shield for the VENUS detector [1] at the TRISTAN electron-positron collider [2]. This device has been successfully used as a beam background shield and as a luminosity monitor of the VENUS detector.

  4. Design of Surface-Active Artificial Enzyme Particles to Stabilize Pickering Emulsions for High-Performance Biphasic Biocatalysis.

    PubMed

    Chen, Zhaowei; Zhao, Chuanqi; Ju, Enguo; Ji, Haiwei; Ren, Jinsong; Binks, Bernard P; Qu, Xiaogang

    2016-02-24

    Surface-active artificial enzymes (SAEs) are designed and constructed by a general and novel strategy. These SAEs can simultaneously stabilize Pickering emulsions and catalyze biphasic biotransformation with superior enzymatic stability and good re-usability; for example, for the interfacial conversion of hydrophobic p-nitrophenyl butyrate into yellow water-soluble p-nitrophenolate catalyzed by esterase-mimic SAE.

  5. Orion Flight Performance Design Trades

    NASA Technical Reports Server (NTRS)

    Jackson, Mark C.; Straube, Timothy

    2010-01-01

    A significant portion of the Orion pre-PDR design effort has focused on balancing mass with performance. High level performance metrics include abort success rates, lunar surface coverage, landing accuracy and touchdown loads. These metrics may be converted to parameters that affect mass, such as ballast for stabilizing the abort vehicle, propellant to achieve increased lunar coverage or extended missions, or ballast to increase the lift-to-drag ratio to improve entry and landing performance. The Orion Flight Dynamics team was tasked to perform analyses to evaluate many of these trades. These analyses not only provide insight into the physics of each particular trade but, in aggregate, they illustrate the processes used by Orion to balance performance and mass margins, and thereby make design decisions. Lessons learned can be gleaned from a review of these studies which will be useful to other spacecraft system designers. These lessons fall into several categories, including: appropriate application of Monte Carlo analysis in design trades, managing margin in a highly mass-constrained environment, and the use of requirements to balance margin between subsystems and components. This paper provides a review of some of the trades and analyses conducted by the Flight Dynamics team, as well as systems engineering lessons learned.

  6. Enabling People with Developmental Disabilities to Actively Follow Simple Instructions and Perform Designated Occupational Activities According to Simple Instructions with Battery-Free Wireless Mice by Controlling Environmental Stimulation

    ERIC Educational Resources Information Center

    Shih, Ching-Hsiang; Chang, Man-Ling

    2012-01-01

    This study extended Battery-free wireless mouse functionality to assess whether two people with developmental disabilities would be able to actively perform designated simple occupational activities according to simple instructions by controlling their favorite environmental stimulation using Battery-free wireless mice with a newly developed…

  7. Software Performs Complex Design Analysis

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Designers use computational fluid dynamics (CFD) to gain greater understanding of the fluid flow phenomena involved in components being designed. They also use finite element analysis (FEA) as a tool to help gain greater understanding of the structural response of components to loads, stresses and strains, and the prediction of failure modes. Automated CFD and FEA engineering design has centered on shape optimization, which has been hindered by two major problems: 1) inadequate shape parameterization algorithms, and 2) inadequate algorithms for CFD and FEA grid modification. Working with software engineers at Stennis Space Center, a NASA commercial partner, Optimal Solutions Software LLC, was able to utilize its revolutionary, one-of-a-kind arbitrary shape deformation (ASD) capability-a major advancement in solving these two aforementioned problems-to optimize the shapes of complex pipe components that transport highly sensitive fluids. The ASD technology solves the problem of inadequate shape parameterization algorithms by allowing the CFD designers to freely create their own shape parameters, therefore eliminating the restriction of only being able to use the computer-aided design (CAD) parameters. The problem of inadequate algorithms for CFD grid modification is solved by the fact that the new software performs a smooth volumetric deformation. This eliminates the extremely costly process of having to remesh the grid for every shape change desired. The program can perform a design change in a markedly reduced amount of time, a process that would traditionally involve the designer returning to the CAD model to reshape and then remesh the shapes, something that has been known to take hours, days-even weeks or months-depending upon the size of the model.

  8. Design Activity Framework for Visualization Design.

    PubMed

    McKenna, Sean; Mazur, Dominika; Agutter, James; Meyer, Miriah

    2014-12-01

    An important aspect in visualization design is the connection between what a designer does and the decisions the designer makes. Existing design process models, however, do not explicitly link back to models for visualization design decisions. We bridge this gap by introducing the design activity framework, a process model that explicitly connects to the nested model, a well-known visualization design decision model. The framework includes four overlapping activities that characterize the design process, with each activity explicating outcomes related to the nested model. Additionally, we describe and characterize a list of exemplar methods and how they overlap among these activities. The design activity framework is the result of reflective discussions from a collaboration on a visualization redesign project, the details of which we describe to ground the framework in a real-world design process. Lastly, from this redesign project we provide several research outcomes in the domain of cybersecurity, including an extended data abstraction and rich opportunities for future visualization research. PMID:26356933

  9. Design Activity Framework for Visualization Design.

    PubMed

    McKenna, Sean; Mazur, Dominika; Agutter, James; Meyer, Miriah

    2014-12-01

    An important aspect in visualization design is the connection between what a designer does and the decisions the designer makes. Existing design process models, however, do not explicitly link back to models for visualization design decisions. We bridge this gap by introducing the design activity framework, a process model that explicitly connects to the nested model, a well-known visualization design decision model. The framework includes four overlapping activities that characterize the design process, with each activity explicating outcomes related to the nested model. Additionally, we describe and characterize a list of exemplar methods and how they overlap among these activities. The design activity framework is the result of reflective discussions from a collaboration on a visualization redesign project, the details of which we describe to ground the framework in a real-world design process. Lastly, from this redesign project we provide several research outcomes in the domain of cybersecurity, including an extended data abstraction and rich opportunities for future visualization research.

  10. An investigation of signal performance enhancements achieved through innovative pixel design across several generations of indirect detection, active matrix, flat-panel arrays

    SciTech Connect

    Antonuk, Larry E.; Zhao Qihua; El-Mohri, Youcef; Du Hong; Wang Yi; Street, Robert A.; Ho, Jackson; Weisfield, Richard; Yao, William

    2009-07-15

    Active matrix flat-panel imager (AMFPI) technology is being employed for an increasing variety of imaging applications. An important element in the adoption of this technology has been significant ongoing improvements in optical signal collection achieved through innovations in indirect detection array pixel design. Such improvements have a particularly beneficial effect on performance in applications involving low exposures and/or high spatial frequencies, where detective quantum efficiency is strongly reduced due to the relatively high level of additive electronic noise compared to signal levels of AMFPI devices. In this article, an examination of various signal properties, as determined through measurements and calculations related to novel array designs, is reported in the context of the evolution of AMFPI pixel design. For these studies, dark, optical, and radiation signal measurements were performed on prototype imagers incorporating a variety of increasingly sophisticated array designs, with pixel pitches ranging from 75 to 127 {mu}m. For each design, detailed measurements of fundamental pixel-level properties conducted under radiographic and fluoroscopic operating conditions are reported and the results are compared. A series of 127 {mu}m pitch arrays employing discrete photodiodes culminated in a novel design providing an optical fill factor of {approx}80% (thereby assuring improved x-ray sensitivity), and demonstrating low dark current, very low charge trapping and charge release, and a large range of linear signal response. In two of the designs having 75 and 90 {mu}m pitches, a novel continuous photodiode structure was found to provide fill factors that approach the theoretical maximum of 100%. Both sets of novel designs achieved large fill factors by employing architectures in which some, or all of the photodiode structure was elevated above the plane of the pixel addressing transistor. Generally, enhancement of the fill factor in either discrete or

  11. An investigation of signal performance enhancements achieved through innovative pixel design across several generations of indirect detection, active matrix, flat-panel arrays

    PubMed Central

    Antonuk, Larry E.; Zhao, Qihua; El-Mohri, Youcef; Du, Hong; Wang, Yi; Street, Robert A.; Ho, Jackson; Weisfield, Richard; Yao, William

    2009-01-01

    Active matrix flat-panel imager (AMFPI) technology is being employed for an increasing variety of imaging applications. An important element in the adoption of this technology has been significant ongoing improvements in optical signal collection achieved through innovations in indirect detection array pixel design. Such improvements have a particularly beneficial effect on performance in applications involving low exposures and∕or high spatial frequencies, where detective quantum efficiency is strongly reduced due to the relatively high level of additive electronic noise compared to signal levels of AMFPI devices. In this article, an examination of various signal properties, as determined through measurements and calculations related to novel array designs, is reported in the context of the evolution of AMFPI pixel design. For these studies, dark, optical, and radiation signal measurements were performed on prototype imagers incorporating a variety of increasingly sophisticated array designs, with pixel pitches ranging from 75 to 127 μm. For each design, detailed measurements of fundamental pixel-level properties conducted under radiographic and fluoroscopic operating conditions are reported and the results are compared. A series of 127 μm pitch arrays employing discrete photodiodes culminated in a novel design providing an optical fill factor of ∼80% (thereby assuring improved x-ray sensitivity), and demonstrating low dark current, very low charge trapping and charge release, and a large range of linear signal response. In two of the designs having 75 and 90 μm pitches, a novel continuous photodiode structure was found to provide fill factors that approach the theoretical maximum of 100%. Both sets of novel designs achieved large fill factors by employing architectures in which some, or all of the photodiode structure was elevated above the plane of the pixel addressing transistor. Generally, enhancement of the fill factor in either discrete or continuous

  12. Performance Based Education. Technology Activity Modules.

    ERIC Educational Resources Information Center

    Custer, Rodney L., Ed.

    These Technology Activity Modules are designed to serve as an implementation resource for technology education teachers as they integrate technology education with Missouri's Academic Performance Standards and provide a source of activities and activity ideas that can be used to integrate and reinforce learning across the curriculum. The modules…

  13. Salt site performance assessment activities

    SciTech Connect

    Kircher, J.F.; Gupta, S.K.

    1983-01-01

    During this year the first selection of the tools (codes) for performance assessments of potential salt sites have been tentatively selected and documented; the emphasis has shifted from code development to applications. During this period prior to detailed characterization of a salt site, the focus is on bounding calculations, sensitivity and with the data available. The development and application of improved methods for sensitivity and uncertainty analysis is a focus for the coming years activities and the subject of a following paper in these proceedings. Although the assessments to date are preliminary and based on admittedly scant data, the results indicate that suitable salt sites can be identified and repository subsystems designed which will meet the established criteria for protecting the health and safety of the public. 36 references, 5 figures, 2 tables.

  14. Relationships Between Design Characteristics of Avionics Subsystems and Training Cost, Training Difficulty, and Job Performance. Final Report, Covering Activity from 1 July 1971 Through 1 September 1972.

    ERIC Educational Resources Information Center

    Lintz, Larry M.; And Others

    A study investigated the relationship between avionics subsystem design characteristics and training time, training cost, and job performance. A list of design variables believed to affect training and job performance was established and supplemented with personnel variables, including aptitude test scores and the amount of training and…

  15. Designing Electronic Performance Support Systems.

    ERIC Educational Resources Information Center

    Barker, Philip; Banerji, Ashok

    1995-01-01

    Outlines the basic nature of performance support and describes a generic model that can be used to facilitate electronic performance support system (EPSS) development. Performance measures are discussed; performance support guidelines are summarized; and a case study of the use of an EPSS is presented. (LRW)

  16. Receiver design and performance characteristics

    NASA Technical Reports Server (NTRS)

    Simon, M. K.; Yuen, J. H.

    1982-01-01

    The basic design, principles of operation, and characteristics of deep space communications receivers are examined. In particular, the basic fundamentals of phase-locked loop and Costas loop receivers used for synchronization, tracking, and demodulation of phase-coherent signals in residual carrier and suppressed carrier systems are addressed.

  17. Receiver design and performance characteristics

    NASA Astrophysics Data System (ADS)

    Simon, M. K.; Yuen, J. H.

    1982-07-01

    The basic design, principles of operation, and characteristics of deep space communications receivers are examined. In particular, the basic fundamentals of phase-locked loop and Costas loop receivers used for synchronization, tracking, and demodulation of phase-coherent signals in residual carrier and suppressed carrier systems are addressed.

  18. How Coriolis meter design affects field performance

    SciTech Connect

    Levien, A.; Dudiak, A.

    1995-12-31

    Although many possibilities exist for the design of Coriolis flowmeters, a common set of fundamental physical principles affect practical meter design. Design criteria such as tube geometry, alloy section, operating frequencies, stress levels, and tubing wall thickness have varying impacts on meter performance. Additionally, field conditions such as changing temperature, pressure, pipeline stress and vibration affect measurement performance. The challenge created in Coriolis flow meter design is to maximize the sensitivity of the meter Coriolis forces, while minimizing the impact of outside environmental influences. Data are presented on the physical principles that affect Coriolis flowmeters, and how the various aspects of meter design influence field performance.

  19. Visual Narrative Research Methods as Performance in Industrial Design Education

    ERIC Educational Resources Information Center

    Campbell, Laurel H.; McDonagh, Deana

    2009-01-01

    This article discusses teaching empathic research methodology as performance. The authors describe their collaboration in an activity to help undergraduate industrial design students learn empathy for others when designing products for use by diverse or underrepresented people. The authors propose that an industrial design curriculum would benefit…

  20. Design: a voice activated thermostat.

    PubMed

    Jacobson, S

    1992-01-01

    The voice activated thermostat was designed so the temperature in a house could be set without having to touch the thermostat. This is especially useful for a quadriplegic who would like to change the temperature of the room he is in. For simplicity, it was designed using VCP200 speaker-independent word recognizer chip. This chip comes pre-programmed with a limited number of words, so programming of words was not necessary. Every time the activation word is said the digital thermostat changes by one degree.

  1. Business School's Performance Management System Standards Design

    ERIC Educational Resources Information Center

    Azis, Anton Mulyono; Simatupang, Togar M.; Wibisono, Dermawan; Basri, Mursyid Hasan

    2014-01-01

    This paper aims to compare various Performance Management Systems (PMS) for business school in order to find the strengths of each standard as inputs to design new model of PMS. There are many critical aspects and gaps notified for new model to improve performance and even recognized that self evaluation performance management is not well…

  2. Performance-based asphalt mixture design methodology

    NASA Astrophysics Data System (ADS)

    Ali, Al-Hosain Mansour

    Today, several State D.O.T.s are being investigating the use of tire rubber with local conventional materials. Several of the ongoing investigations identified potential benefits from the use of these materials, including improvements in material properties and performance. One of the major problems is being associated with the transferability of asphalt rubber technology without appropriately considering the effects of the variety of conventional materials on mixture behavior and performance. Typically, the design of these mixtures is being adapted to the physical properties of the conventional materials by using the empirical Marshall mixture design and without considering fundamental mixture behavior and performance. Use of design criteria related to the most common modes of failure for asphalt mixtures, such as rutting, fatigue cracking, and low temperature thermal cracking have to be developed and used for identifying the "best mixture," in term of performance, for the specific local materials and loading conditions. The main objective of this study was the development of a mixture design methodology that considers mixture behavior and performance. In order to achieve this objective a laboratory investigation able to evaluate mixture properties that can be related to mixture performance, (in terms of rutting, low temperature cracking, moisture damage and fatigue), and simulating the actual field loading conditions that the material is being exposed to, was conducted. The results proved that the inclusion of rubber into asphalt mixtures improved physical characteristics such as elasticity, flexibility, rebound, aging properties, increased fatigue resistance, and reduced rutting potential. The possibility of coupling the traditional Marshall mix design method with parameters related to mixture behavior and performance was investigated. Also, the SHRP SUPERPAVE mix design methodology was reviewed and considered in this study for the development of an integrated

  3. Co-design for High Performance Computing

    NASA Astrophysics Data System (ADS)

    Rodrigues, Arun; Dosanjh, Sudip; Hemmert, Scott

    2010-09-01

    Co-design has been identified as a key strategy for achieving Exascale computing in this decade. This paper describes the need for co-design in High Performance Computing related research in embedded computing the development of hardware/software co-simulation methods.

  4. A Perspective on Computational Human Performance Models as Design Tools

    NASA Technical Reports Server (NTRS)

    Jones, Patricia M.

    2010-01-01

    The design of interactive systems, including levels of automation, displays, and controls, is usually based on design guidelines and iterative empirical prototyping. A complementary approach is to use computational human performance models to evaluate designs. An integrated strategy of model-based and empirical test and evaluation activities is particularly attractive as a methodology for verification and validation of human-rated systems for commercial space. This talk will review several computational human performance modeling approaches and their applicability to design of display and control requirements.

  5. Performance indicators of work activity.

    PubMed

    Lahoz, Manoela de Assis; Camarotto, João Alberto

    2012-01-01

    The measurement of performance is a current topic in the management of people in companies, used as a parameter of effectiveness of processes and operations of production. The methods and models of the indicators of current use in the production have concentrated in the assessment of people's performance as determinative resource of the organizational success in the search for the competitiveness. Associated with the classic indicators of performance assessment of the production proceeding, other indicators are used in the assessment of risks and hazards, however with methods focused in the tasks, without connection with the real work activity. The present article explores literature on the models of performance measurement in use in companies and a field research to understand how companies interpret and use indicators that relate health and work, to direct future studies on the subject. Regarding the literature review, one can see that health indicators can be basically divided into two major groups: the legal and managerial indicators. When conducting case studies, it can be realized that companies do not have precisely the concept of health indicator, or were unable to define which of the indicators could be considered indicators of health, considering that absenteeism was the indicator mentioned by the four companies.

  6. Safety performance functions incorporating design consistency variables.

    PubMed

    Montella, Alfonso; Imbriani, Lella Liana

    2015-01-01

    Highway design which ensures that successive elements are coordinated in such a way as to produce harmonious and homogeneous driver performances along the road is considered consistent and safe. On the other hand, an alignment which requires drivers to handle high speed gradients and does not meet drivers' expectancy is considered inconsistent and produces higher crash frequency. To increase the usefulness and the reliability of existing safety performance functions and contribute to solve inconsistencies of existing highways as well as inconsistencies arising in the design phase, we developed safety performance functions for rural motorways that incorporate design consistency measures. Since the design consistency variables were used only for curves, two different sets of models were fitted for tangents and curves. Models for the following crash characteristics were fitted: total, single-vehicle run-off-the-road, other single vehicle, multi vehicle, daytime, nighttime, non-rainy weather, rainy weather, dry pavement, wet pavement, property damage only, slight injury, and severe injury (including fatal). The design consistency parameters in this study are based on operating speed models developed through an instrumented vehicle equipped with a GPS continuous speed tracking from a field experiment conducted on the same motorway where the safety performance functions were fitted (motorway A16 in Italy). Study results show that geometric design consistency has a significant effect on safety of rural motorways. Previous studies on the relationship between geometric design consistency and crash frequency focused on two-lane rural highways since these highways have the higher crash rates and are generally characterized by considerable inconsistencies. Our study clearly highlights that the achievement of proper geometric design consistency is a key design element also on motorways because of the safety consequences of design inconsistencies. The design consistency measures

  7. Influence of facemask design on operational performance

    NASA Technical Reports Server (NTRS)

    Griffin, O. G.; Longson, D. J.

    1972-01-01

    Spirometric measurements of oxygen volume and determination of the amount of argon in exhaled breath are used to analyze facemask design efficiency during treadmill walking tests with subjects carrying plastic hoods filled with argon. Facemask leakage measurements established the better performance of a pneumatic seal type mask in comparison with plain seal type masks.

  8. Design and performances of JPCam actuator system

    NASA Astrophysics Data System (ADS)

    Casalta, Joan Manel; Canchado, Manuel; Molins, Albert; Redondo, Miguel; Tomàs, Albert; Catalan, Albert

    2014-07-01

    JPCam is designed to perform the Javalambre-PAU Astrophysical Survey (J-PAS), a photometric survey of the northern sky with the new JST telescope being constructed in the Observatorio Astrofísico of Javalambre in Spain by CEFCA (Centro de Estudios de Física del Cosmos de Aragón). SENER has been responsible for the design, manufacturing, verification and delivery of the JPCam Actuator System that will be installed between the Telescope and the cryogenic Camera Subsystem. The main function is to control the instrument position to guarantee the image quality required during observations in all field of view and compensate deformations produced by gravity and temperature changes. The paper summarizes the main aspects of the hexapod design and earliest information related of integration and performances tests results.

  9. Human visual performance model for crewstation design

    NASA Astrophysics Data System (ADS)

    Larimer, James O.; Prevost, Michael P.; Arditi, Aries R.; Azueta, Steven; Bergen, James R.; Lubin, Jeffrey

    1991-08-01

    In a cockpit, the crewstation of an airplane, the ability of the pilot to unambiguously perceive rapidly changing information both internal and external to the crewstation is critical. To assess the impact of crewstation design decisions on the pilot''s ability to perceive information, the designer needs a means of evaluating the trade-offs that result from different designs. The Visibility Modeling Tool (VMT) provides the designer with a CAD tool for assessing these trade-offs. It combines the technologies of computer graphics, computational geometry, human performance modeling and equipment modeling into a computer-based interactive design tool. Through a simple interactive interface, a designer can manipulate design parameters such as the geometry of the cockpit, environmental factors such as ambient lighting, pilot parameters such as point of regard and adaptation state, and equipment parameters such as the location of displays, their size and the contrast of displayed symbology. VMT provides an end-to-end analysis that answers questions such as ''Will the pilot be able to read the display?'' Performance data can be projected, in the form of 3D contours, into the crewstation graphic model, providing the designer with a footprint of the operator''s visual capabilities, defining, for example, the regions in which fonts of a particular type, size and contrast can be read without error. Geometrical data such as the pilot''s volume field of view, occlusions caused by facial geometry, helmet margins, and objects in the crewstation can also be projected into the crewstation graphic model with respect to the coordinates of the aviator''s eyes and fixation point. The intersections of the projections with objects in the crewstation, delineate the area of coverage, masking, or occlusion associated with the objects. Objects in the crewstation space can be projected onto models of the operator''s retinas. These projections can be used to provide the designer with the

  10. Spacelab carrier complement thermal design and performance

    NASA Astrophysics Data System (ADS)

    Bancroft, S.; Key, R.; Kittredge, S.

    1992-07-01

    The present discussion of the Spacelab carrier complement, which encompasses a Module Carrier, a Module-Pallet Carrier, and a Multiplexer/Demultiplexer Pallet, gives attention to both active and passive thermal performance capabilities, and presents ground testing and analytical results obtained to date. An account is given of the prospective use of a Spacelab Multipurpose Experiment Support Structure.

  11. Spacelab carrier complement thermal design and performance

    NASA Technical Reports Server (NTRS)

    Bancroft, S.; Key, R.; Kittredge, S.

    1992-01-01

    The present discussion of the Spacelab carrier complement, which encompasses a Module Carrier, a Module-Pallet Carrier, and a Multiplexer/Demultiplexer Pallet, gives attention to both active and passive thermal performance capabilities, and presents ground testing and analytical results obtained to date. An account is given of the prospective use of a Spacelab Multipurpose Experiment Support Structure.

  12. Design and performance of the beamlet amplifiers

    SciTech Connect

    Erlandson, A.C.; Rotter, M.D.; Frank, M.D.; McCracken, R.W.

    1996-06-01

    In future laser systems, such as the National Ignition Facility (NIF), multi-segment amplifiers (MSAs) will be used to amplify the laser beam to the required levels. As a prototype of such a laser architecture, the authors have designed, built, and tested flash-lamp-pumped, Nd:Glass, Brewster-angle slab MSAs for the Beamlet project. In this article, they review the fundamentals of Nd:Glass amplifiers, describe the MSA geometry, discuss parameters that are important in amplifier design, and present our results on the characterization of the Beamlet MSAs. In particular, gain and beam steering measurements show that the Beamlet amplifiers meet all optical performance specifications and perform close to model predictions.

  13. Radome design and performance - A review

    NASA Astrophysics Data System (ADS)

    Rudge, A. W.; Crone, G. A. E.; Summers, J.

    The rapid growth and development of techniques for electromagnetic jamming of radar and communication systems has led to enhanced interest in the design of antenna systems with improved electrical performance. Low sidelobe, multifrequency, and wider bandwidth antenna systems are of particular interest. For many applications the antenna will be enclosed by a radome and the overall system performance will be critically dependent upon the characteristics of this electromagnetic window. Radome applications are discussed, taking into account radomes for terrestrial or sea-borne radars, radomes for terrestrial communications, airborne radomes, rain erosion, and radomes for satellite communications. Radome materials are discussed, giving attention to glass fiber reinforced plastics, modified dielectric core materials, and missile radome materials. A description of electromagnetic analysis and design techniques is also provided.

  14. Influence of Design Variations on Systems Performance

    NASA Technical Reports Server (NTRS)

    Tumer, Irem Y.; Stone, Robert B.; Huff, Edward M.; Norvig, Peter (Technical Monitor)

    2000-01-01

    High-risk aerospace components have to meet very stringent quality, performance, and safety requirements. Any source of variation is a concern, as it may result in scrap or rework. poor performance, and potentially unsafe flying conditions. The sources of variation during product development, including design, manufacturing, and assembly, and during operation are shown. Sources of static and dynamic variation during development need to be detected accurately in order to prevent failure when the components are placed in operation. The Systems' Health and Safety (SHAS) research at the NASA Ames Research Center addresses the problem of detecting and evaluating the statistical variation in helicopter transmissions. In this work, we focus on the variations caused by design, manufacturing, and assembly of these components, prior to being placed in operation (DMV). In particular, we aim to understand and represent the failure and variation information, and their correlation to performance and safety and feed this information back into the development cycle at an early stage. The feedback of such critical information will assure the development of more reliable components with less rework and scrap. Variations during design and manufacturing are a common source of concern in the development and production of such components. Accounting for these variations, especially those that have the potential to affect performance, is accomplished in a variety ways, including Taguchi methods, FMEA, quality control, statistical process control, and variation risk management. In this work, we start with the assumption that any of these variations can be represented mathematically, and accounted for by using analytical tools incorporating these mathematical representations. In this paper, we concentrate on variations that are introduced during design. Variations introduced during manufacturing are investigated in parallel work.

  15. Reactive barriers: hydraulic performance and design enhancements.

    PubMed

    Painter, B D M

    2004-01-01

    The remediation of contaminated ground water is a multibillion-dollar global industry. Permeable reactive barriers (PRBs) are one of the leading technologies being developed in the search for alternatives to the pump-and-treat method. Improving the hydraulic performance of these PRBs is an important part of maximizing their potential to the industry. Optimization of the hydraulic performance of a PRB can be defined in terms of finding the balance between capture, residence time, and PRB longevity that produces a minimum-cost acceptable design. Three-dimensional particle tracking was used to estimate capture zone and residence time distributions. Volumetric flow analysis was used for estimation of flow distribution across a PRB and in the identification of flow regimes that may affect the permeability or reactivity of portions of the PRB over time. Capture zone measurements extended below the base of partially penetrating PRBs and were measured upgradient from the portion of aquifer influenced by PRB emplacement. Hydraulic performance analysis of standard PRB designs confirmed previously presented research that identified the potential for significant variation in residence time and capture zone. These variations can result in the need to oversize the PRB to ensure that downgradient contaminant concentrations do not exceed imposed standards. The most useful PRB design enhancements for controlling residence time and capture variation were found to be customized downgradient gate faces, velocity equalization walls, deeper emplacement of the funnel than the gate, and careful manipulation of the hydraulic conductivity ratio between the gate and the aquifer.

  16. Assessing design activity in complex CMOS circuit design

    NASA Astrophysics Data System (ADS)

    Biswas, Gautam; Goldman, Susan R.; Fisher, Doug; Bhuva, Bharat; Glewwe, Grant

    1994-03-01

    This chapter characterizes human problem solving in digital circuit design. We analyze protocols of designers with varying degrees of training, identifying problem solving strategies used by these designers, discuss activity patterns that differentiate designers, and propose these as a tentative basis for assessing expertise in digital design. Throughout, we argue that a comprehensive model of human design should integrate a variety of strategies, which heretofore have been proposed as individually sufficient models of human design problem solving. We close by describing an automated tool for design and its assessment.

  17. Designer protein-based performance materials.

    PubMed

    Kumar, Manoj; Sanford, Karl J; Cuevas, William A; Cuevas, William P; Du, Mai; Collier, Katharine D; Chow, Nicole

    2006-09-01

    Repeat sequence protein polymer (RSPP) technology provides a platform to design and make protein-based performance polymers and represents the best nature has to offer. We report here that the RSPP platform is a novel approach to produce functional protein polymers that have both biomechanical and biofunctional blocks built into one molecule by design, using peptide motifs. We have shown that protein-based designer biopolymers can be made using recombinant DNA technology and fermentation and offer the ability to screen for desired properties utilizing the tremendous potential diversity of amino acid combinations. The technology also allows for large-scale manufacturing with a favorable fermentative cost-structure to deliver commercially viable performance polymers. Using three diverse examples with antimicrobial, textile targeting, and UV-protective agent, we have introduced functional attributes into structural protein polymers and shown, for example, that the functionalized RSPPs have possible applications in biodefense, industrial biotechnology, and personal care areas. This new class of biobased materials will simulate natural biomaterials that can be modified for desired function and have many advantages over conventional petroleum-based polymers.

  18. High performance APCS conceptual design and evaluation scoping study

    SciTech Connect

    Soelberg, N.; Liekhus, K.; Chambers, A.; Anderson, G.

    1998-02-01

    This Air Pollution Control System (APCS) Conceptual Design and Evaluation study was conducted to evaluate a high-performance (APC) system for minimizing air emissions from mixed waste thermal treatment systems. Seven variations of high-performance APCS designs were conceptualized using several design objectives. One of the system designs was selected for detailed process simulation using ASPEN PLUS to determine material and energy balances and evaluate performance. Installed system capital costs were also estimated. Sensitivity studies were conducted to evaluate the incremental cost and benefit of added carbon adsorber beds for mercury control, specific catalytic reduction for NO{sub x} control, and offgas retention tanks for holding the offgas until sample analysis is conducted to verify that the offgas meets emission limits. Results show that the high-performance dry-wet APCS can easily meet all expected emission limits except for possibly mercury. The capability to achieve high levels of mercury control (potentially necessary for thermally treating some DOE mixed streams) could not be validated using current performance data for mercury control technologies. The engineering approach and ASPEN PLUS modeling tool developed and used in this study identified APC equipment and system performance, size, cost, and other issues that are not yet resolved. These issues need to be addressed in feasibility studies and conceptual designs for new facilities or for determining how to modify existing facilities to meet expected emission limits. The ASPEN PLUS process simulation with current and refined input assumptions and calculations can be used to provide system performance information for decision-making, identifying best options, estimating costs, reducing the potential for emission violations, providing information needed for waste flow analysis, incorporating new APCS technologies in existing designs, or performing facility design and permitting activities.

  19. Design of high performance piezo composites actuators

    NASA Astrophysics Data System (ADS)

    Almajid, Abdulhakim A.

    Design of high performance piezo composites actuators are developed. Functionally Graded Microstructure (FGM) piezoelectric actuators are designed to reduce the stress concentration at the middle interface existed in the standard bimorph actuators while maintaining high actuation performance. The FGM piezoelectric laminates are composite materials with electroelastic properties varied through the laminate thickness. The elastic behavior of piezo-laminates actuators is developed using a 2D-elasticity model and a modified classical lamination theory (CLT). The stresses and out-of-plane displacements are obtained for standard and FGM piezoelectric bimorph plates under cylindrical bending generated by an electric field throughout the thickness of the laminate. The analytical model is developed for two different actuator geometries, a rectangular plate actuator and a disk shape actuator. The limitations of CLT are investigated against the 2D-elasticity model for the rectangular plate geometry. The analytical models based on CLT (rectangular and circular) and 2D-elasticity are compared with a model based on Finite Element Method (FEM). The experimental study consists of two FGM actuator systems, the PZT/PZT FGM system and the porous FGM system. The electroelastic properties of each layer in the FGM systems were measured and input in the analytical models to predict the FGM actuator performance. The performance of the FGM actuator is optimized by manipulating the thickness of each layer in the FGM system. The thickness of each layer in the FGM system is made to vary in a linear or non-linear manner to achieve the best performance of the FGM piezoelectric actuator. The analytical and FEM results are found to agree well with the experimental measurements for both rectangular and disk actuators. CLT solutions are found to coincide well with the elasticity solutions for high aspect ratios while the CLT solutions gave poor results compared to the 2D elasticity solutions for

  20. Designing for the Active Classroom

    SciTech Connect

    Wilkerson, Andrea M.; Donohue, Amy; Davis, Robert G.

    2015-02-01

    The article discusses trends in classroom design and then transitions to a discussion of the future of the classroom and how the lighting industry needs to be preparing to meet the needs of the future classroom. The OSU Classroom building as an example throughout, first discussing how trends in classroom design were incorporated into the Classroom Building and then discussing how future lighting systems could enhance the Classroom Building, which is a clear departure from the actual lighting design and current technology.

  1. Improving DNA vaccine performance through vector design.

    PubMed

    Williams, James A

    2014-01-01

    DNA vaccines are a rapidly deployed next generation vaccination platform for treatment of human and animal disease. DNA delivery devices, such as electroporation and needle free jet injectors, are used to increase gene transfer. This results in higher antigen expression which correlates with improved humoral and cellular immunity in humans and animals. This review highlights recent vector and transgene design innovations that improve DNA vaccine performance. These new vectors improve antigen expression, increase plasmid manufacturing yield and quality in bioreactors, and eliminate antibiotic selection and other potential safety issues. A flowchart for designing synthetic antigen transgenes, combining antigen targeting, codon-optimization and bioinformatics, is presented. Application of improved vectors, of antibiotic free plasmid production, and cost effective manufacturing technologies will be critical to ensure safety, efficacy, and economically viable manufacturing of DNA vaccines currently under development for infectious disease, cancer, autoimmunity, immunotolerance and allergy indications.

  2. Multi-rail barrel design and performance

    NASA Astrophysics Data System (ADS)

    Maas, Brian L.; Bauer, David P.; Challita, Antonios

    1993-01-01

    Railgun barrels containing multiple isolated rail pairs can be used to control armature current distribution and/or to obtain independent circuits for use with specialized power supplies. Armature current control can be used to effectively distribute acceleration forces for improved projectile launch. Independent rail 'load' circuits are attractive for use with some power supplies such as a polyphase compulsator. We have built and tested a 30 mm barrel containing three distinct rail pairs. These three rail pairs were powered by separate power supplies. This paper describes issues associated with multi-rail barrel design and our band design and performance. Rail alignment, isolation, and construction are described. The effect of multiple rail pairs on the effective inductance gradient of the band is described and test results are provided.

  3. Cereal Box Design: An Interdisciplinary Graphics Activity

    ERIC Educational Resources Information Center

    Fitzgerald, Mike; Tsosie, Teri

    2004-01-01

    This article describes cereal box design, an interdisciplinary graphics activity. The cereal box design activity is intriguing both for its simplicity and the resourcefulness that it can generate in young people. It lends itself to a variety of curriculums. It covers both consumerism and Design for the Environment (DfE) concepts broadly and in…

  4. Human visual performance model for crewstation design

    NASA Technical Reports Server (NTRS)

    Larimer, James; Prevost, Michael; Arditi, Aries; Azueta, Steven; Bergen, James; Lubin, Jeffrey

    1991-01-01

    An account is given of a Visibility Modeling Tool (VMT) which furnishes a crew-station designer with the means to assess configurational tradeoffs, with a view to the impact of various options on the unambiguous access of information to the pilot. The interactive interface of the VMT allows the manipulation of cockpit geometry, ambient lighting, pilot ergonomics, and the displayed symbology. Performance data can be displayed in the form of 3D contours into the crewstation graphic model, thereby yielding an indication of the operator's visual capabilities.

  5. Cold climate wetlands: design and performance.

    PubMed

    Wallace, S; Parkin, G; Cross, C

    2001-01-01

    Constructed wetlands are gaining widespread use as a simple, low cost means of wastewater treatment. Introduction of constructed wetlands technology into the northern United States has been limited by the ability of conventional wetland systems to operate without freezing during the winter. A design approach using subsurface-flow constructed wetlands covered with an insulating mulch layer has been demonstrated to prevent freezing. However, introduction of a mulch layer will affect oxygen transfer rates, pollutant removal performance, and plant establishment. These factors must be addressed for successful application of constructed wetlands technology in cold climates.

  6. The design, validation, and performance of Grace

    NASA Astrophysics Data System (ADS)

    Zhu, Ru

    2016-05-01

    The design, validation and performance of Grace, a GPU-accelerated micromagnetic simulation software, are presented. The software adopts C+ + Accelerated Massive Parallelism (C+ + AMP) so that it runs on GPUs from various hardware vendors including NVidia, AMD and Intel. At large simulation scales, up to two orders of magnitude of speedup factor is observed, compared to CPU-based micromagnetic simulation software OOMMF. The software can run on high-end professional GPUs as well as budget personal laptops, and is free to download.

  7. ACCESS: Thermal Mechanical Design, Performance, and Status

    NASA Astrophysics Data System (ADS)

    Kaiser, Mary Elizabeth; Morris, M. J.; McCandliss, S. R.; Rauscher, B. J.; Kimble, R. A.; Kruk, J. W.; Wright, E. L.; Bohlin, R.; Kurucz, R. L.; Riess, A. G.; Pelton, R.; Deustua, S. E.; Dixon, W. V.; Sahnow, D. J.; Benford, D. J.; Gardner, J. P.; Feldman, P. D.; Moos, H. W.; Lampton, M.; Perlmutter, S.; Woodgate, B. E.

    2014-01-01

    Systematic errors associated with astrophysical data used to probe fundamental astrophysical questions, such as SNeIa observations used to constrain dark energy theories, are now rivaling and exceeding the statistical errors associated with these measurements. ACCESS: Absolute Color Calibration Experiment for Standard Stars is a series of rocket-borne sub-orbital missions and ground-based experiments designed to enable improvements in the precision of the astrophysical flux scale through the transfer of absolute laboratory detector standards from the National Institute of Standards and Technology (NIST) to a network of stellar standards with a calibration accuracy of 1% and a spectral resolving power of 500 across the 0.35 - 1.7μm bandpass. Achieving this level of accuracy requires characterization and stability of the instrument and detector including a thermal background that contributes less than 1% to the flux per resolution element in the NIR. We will present the instrument and calibration status with a focus on the thermal mechanical design and associated performance data. The detector control and performance will be presented in a companion poster (Morris, et al). NASA APRA sounding rocket grant NNX08AI65G supports this work.

  8. Persistent Focal Behavior and Physical Activity Performance

    ERIC Educational Resources Information Center

    Erfle, Stephen E.

    2014-01-01

    This article examines the proclivity and performance attributes of focal students across time and activities using data from 9,345 students. Three systematic focal behavior partitions are examined: Across activities, across time, and across activities and time. A student's performance is focal if it ends in 0 or 5 for push-ups and 0 for…

  9. Extravehicular activity training and hardware design consideration.

    PubMed

    Thuot, P J; Harbaugh, G J

    1995-07-01

    Preparing astronauts to perform the many complex extravehicular activity (EVA) tasks required to assemble and maintain Space Station will be accomplished through training simulations in a variety of facilities. The adequacy of this training is dependent on a thorough understanding of the task to be performed, the environment in which the task will be performed, high-fidelity training hardware and an awareness of the limitations of each particular training facility. Designing hardware that can be successfully operated, or assembled, by EVA astronauts in an efficient manner, requires an acute understanding of human factors and the capabilities and limitations of the space-suited astronaut. Additionally, the significant effect the microgravity environment has on the crew members' capabilities has to be carefully considered not only for each particular task, but also for all the overhead related to the task and the general overhead associated with EVA. This paper will describe various training methods and facilities that will be used to train EVA astronauts for Space Station assembly and maintenance. User-friendly EVA hardware design considerations and recent EVA flight experience will also be presented. PMID:11541312

  10. Extravehicular activity training and hardware design consideration.

    PubMed

    Thuot, P J; Harbaugh, G J

    1995-07-01

    Preparing astronauts to perform the many complex extravehicular activity (EVA) tasks required to assemble and maintain Space Station will be accomplished through training simulations in a variety of facilities. The adequacy of this training is dependent on a thorough understanding of the task to be performed, the environment in which the task will be performed, high-fidelity training hardware and an awareness of the limitations of each particular training facility. Designing hardware that can be successfully operated, or assembled, by EVA astronauts in an efficient manner, requires an acute understanding of human factors and the capabilities and limitations of the space-suited astronaut. Additionally, the significant effect the microgravity environment has on the crew members' capabilities has to be carefully considered not only for each particular task, but also for all the overhead related to the task and the general overhead associated with EVA. This paper will describe various training methods and facilities that will be used to train EVA astronauts for Space Station assembly and maintenance. User-friendly EVA hardware design considerations and recent EVA flight experience will also be presented.

  11. Designing Instructional Activities for Young Handicapped Children.

    ERIC Educational Resources Information Center

    Kaczmarek, Louise A.; Dell, Amy Glasser

    1981-01-01

    Proposed are several new directions that encourage the variety and flexibility of haphazard teaching and the precision of one objective-one activity teaching in the design of activities for handicapped preschoolers. Journal availability: see EC 133 846. (Author)

  12. Ram-Jet off Design Performances

    NASA Astrophysics Data System (ADS)

    Andriani, Roberto; Ghezzi, Umberto

    2002-01-01

    In this work it is intended to study the off-design performances of a ram jet engine. To this purpouse it has been analyzed in a first time the behaviour of an ideal engine, that means to not consider the losses in the various components, or, under a thermodynamic point of view, to consider the fluid transformation through the air intake and exhaust nozzle, remembering that in a ram jet there are not rotating components as compressor and turbine, isentropic. Referring to the ram-jet scheme of fig.1. we can say, neglecting the fuel introduced, that the air mass flow rate throughout the engine is constant. If we consider the two control sections 4 and 8, respectively the throat section of the converging-diverging supersonic inlet and the throat section of the discharge nozzle, the condition of constant mass flow leads to the relation: m4 =f (M 4 ) m8 = m 4 = m8 We can imaging that the throat section # 4 is always choked for any value of the flight Mach number M0. This means that the throat section 4 is adjusted at any value of M0 so that the flow Mach number in 4 is equal to unity. In this it follows: R. Andriani, U. Ghezzi1 Since in an ideal case T t8 The relation [1] allows to determine the T8 temperature, that represent the maximum cycle temperature, for different operating conditions, as flight Mach number and altitude. We then have two cases: the first is A8 (nozzle throat section) fixed, and the second is A8 variable. In the first case the maximum temperature T8 is univocally determined by the operating condition. In the second case A8 can be varied so to maintain T8 at a chosen value. The graphic of fig.2 shows the first case. In particular it has been considered as design point an altitude of 15000 meters and a flight Mach number equal to 2. In this condition it has been evaluated the section A8 for unity mass flow rate. At the same altitude, varying the flight Mach number, with the section A4 always choked, the graphic shows the variation of the maximum

  13. Cereal Box Design: An Interdisciplinary Graphics Activity

    ERIC Educational Resources Information Center

    Fitzgerald, Mike; Tsosie, Teri

    2012-01-01

    The cereal box design activity is intriguing both for its simplicity and the resourcefulness that it can generate in young people. Also, it lends itself to a variety of curriculums. It covers both consumerism and Design for the Environment (DfE) concepts broadly and in depth. The activity introduces a wide range of topics. They include graphic…

  14. Active magnetic bearings for optimum turbomachinery design

    NASA Technical Reports Server (NTRS)

    Hustak, J.; Kirk, R. G.; Schoeneck, K. A.

    1985-01-01

    The design and shop test results are given for a high speed eight stage centrifugal compressor supported by active magnetic bearings. A brief summary of the rotor dynamics analysis is presented with specific attention given to design considerations for optimum rotor stability. The concerns for retrofit of magnetic bearings in existing machinery are discussed with supporting analysis of a four stage centrifugal compressor. Recommendations are given on design and analysis requirements for successful machinery operation of either retrofit or new design turbomachinery.

  15. ACCESS: Design, Strategy, and Test Performance

    NASA Astrophysics Data System (ADS)

    Kaiser, Mary Elizabeth; Morris, M. J.; McCandliss, S. R.; Rauscher, B. J.; Kimble, R. A.; Kruk, J. W.; Wright, E. L.; Pelton, R. S.; Feldman, P. D.; Moos, H. W.; Riess, A. G.; Benford, D. J.; Foltz, R.; Gardner, J. P.; Mott, D. B.; Wen, Y.; Woodgate, B. E.; Bohlin, R.; Deustua, S. E.; Dixon, W. V.; Sahnow, D. J.; Kurucz, R. L.; Lampton, M.; Perlmutter, S.

    2013-01-01

    Improvements in the astrophysical flux scale are needed to answer fundamental scientific questions ranging from cosmology to stellar physics. In particular, the precise calibration of the flux scale across the visible-NIR bandpass is fundamental to the precise determination of dark energy parameters based on SNeIa photometry. ACCESS, Absolute Color Calibration Experiment for Standard Stars, is a series of rocket-borne sub-orbital missions and ground-based experiments that will enable improvements in the precision of the astrophysical flux scale through the transfer of absolute laboratory detector standards from the National Institute of Standards and Technology (NIST) to a network of stellar standards with a calibration accuracy of 1% and a spectral resolving power of 500 across the 0.35 to 1.7 micron bandpass. The telescope is a Dall-Kirkham Cassegrain with a 15.5-inch primary. The spectrograph is a Rowland circle design, with the grating operating as a low order (m=1-4) echelle, a Fery prism provides cross dispersion, and a HST/WFC3 heritage HAWAII-1R HgCdTe detector is used across the full spectral bandpass. The telescope mirrors have received their flight coatings. The flight detector and detector spare have been integrated with their electronics and flight mount. The controller electronics have been flight qualified. Vibration testing to launch loads and thermal vacuum testing of the detector, mount, and housing have been performed. Detector characterization testing is in progress (Morris et al.). Fabrication, integration, and automation of the ground-based calibration subsystems are also in progress. The ACCESS design, calibration strategy, and ground-based integration and test results will be presented. Launch is expected this year. NASA sounding rocket grant NNX08AI65G and DOE DE-FG02-07ER41506 support this work.

  16. Optimal active vibration absorber: Design and experimental results

    NASA Technical Reports Server (NTRS)

    Lee-Glauser, Gina; Juang, Jer-Nan; Sulla, Jeffrey L.

    1992-01-01

    An optimal active vibration absorber can provide guaranteed closed-loop stability and control for large flexible space structures with collocated sensors/actuators. The active vibration absorber is a second-order dynamic system which is designed to suppress any unwanted structural vibration. This can be designed with minimum knowledge of the controlled system. Two methods for optimizing the active vibration absorber parameters are illustrated: minimum resonant amplitude and frequency matched active controllers. The Controls-Structures Interaction Phase-1 Evolutionary Model at NASA LaRC is used to demonstrate the effectiveness of the active vibration absorber for vibration suppression. Performance is compared numerically and experimentally using acceleration feedback.

  17. Designing Physical Activities for Metaphorical Communication.

    ERIC Educational Resources Information Center

    Gillis, H. Lee; Edwards, Marianne

    1987-01-01

    Presents to student affairs professionals a process for designing physical activities that can actively and metaphorically communicate a message and that can be implemented as part of staff inservice, retreats, or orientations. Describes rationale for activities, historical overview, and example of burnout prevention metaphor for resident…

  18. MTI Focal Plane Assembly Design and Performance

    SciTech Connect

    Ballard, M.; Rienstra, J.L.

    1999-06-17

    The focal plane assembly for the Multispectral Thermal Imager (MTI) consists of sensor chip assemblies, optical filters, and a vacuum enclosure. Sensor chip assemblies, composed of linear detector arrays and readout integrated circuits, provide spatial resolution in the cross-track direction for the pushbroom imager. Optical filters define 15 spectral bands in a range from 0.45 {micro}m to 10.7 {micro}m. All the detector arrays are mounted on a single focal plane and are designed to operate at 75 K. Three pairs of sensor chip assemblies (SCAs) are required to provide cross-track coverage in all 15 spectral bands. Each pair of SCAs includes detector arrays made from silicon, iridium antimonide, and mercury cadmium telluride. Read out integrated circuits multiplex the signals from the detectors to 18 separate video channels. Optical filter assemblies defining the spectral bands are mounted over the linear detector arrays. Each filter assembly consists of several filter strips bonded together side-by-side. The MTI focal plane assembly has been integrated with the rest of the payload and has undergone detailed testing and calibration. This paper includes representative test data for the various spectral bands and the overall performance of the focal plane assembly.

  19. Coherent lidar design and performance verification

    NASA Technical Reports Server (NTRS)

    Frehlich, Rod

    1993-01-01

    The verification of LAWS beam alignment in space can be achieved by a measurement of heterodyne efficiency using the surface return. The crucial element is a direct detection signal that can be identified for each surface return. This should be satisfied for LAWS but will not be satisfied for descoped LAWS. The performance of algorithms for velocity estimation can be described with two basic parameters: the number of coherently detected photo-electrons per estimate and the number of independent signal samples per estimate. The average error of spectral domain velocity estimation algorithms are bounded by a new periodogram Cramer-Rao Bound. Comparison of the periodogram CRB with the exact CRB indicates a factor of two improvement in velocity accuracy is possible using non-spectral domain estimators. This improvement has been demonstrated with a maximum-likelihood estimator. The comparison of velocity estimation algorithms for 2 and 10 micron coherent lidar was performed by assuming all the system design parameters are fixed and the signal statistics are dominated by a 1 m/s rms wind fluctuation over the range gate. The beam alignment requirements for 2 micron are much more severe than for a 10 micron lidar. The effects of the random backscattered field on estimating the alignment error is a major problem for space based lidar operation, especially if the heterodyne efficiency cannot be estimated. For LAWS, the biggest science payoff would result from a short transmitted pulse, on the order of 0.5 microseconds instead of 3 microseconds. The numerically errors for simulation of laser propagation in the atmosphere have been determined as a joint project with the University of California, San Diego. Useful scaling laws were obtained for Kolmogorov atmospheric refractive turbulence and an atmospheric refractive turbulence characterized with an inner scale. This permits verification of the simulation procedure which is essential for the evaluation of the effects of

  20. Comprehensive Design Reliability Activities for Aerospace Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Christenson, R. L.; Whitley, M. R.; Knight, K. C.

    2000-01-01

    This technical publication describes the methodology, model, software tool, input data, and analysis result that support aerospace design reliability studies. The focus of these activities is on propulsion systems mechanical design reliability. The goal of these activities is to support design from a reliability perspective. Paralleling performance analyses in schedule and method, this requires the proper use of metrics in a validated reliability model useful for design, sensitivity, and trade studies. Design reliability analysis in this view is one of several critical design functions. A design reliability method is detailed and two example analyses are provided-one qualitative and the other quantitative. The use of aerospace and commercial data sources for quantification is discussed and sources listed. A tool that was developed to support both types of analyses is presented. Finally, special topics discussed include the development of design criteria, issues of reliability quantification, quality control, and reliability verification.

  1. Metaconcrete: designed aggregates to enhance dynamic performance

    NASA Astrophysics Data System (ADS)

    Mitchell, Stephanie J.; Pandolfi, Anna; Ortiz, Michael

    2014-04-01

    We propose a new type of concrete for the attenuation of elastic waves induced by dynamic excitation. In this metamaterial, which we call metaconcrete, the stone, sand, and gravel aggregates of standard concrete are replaced with spherical inclusions consisting of a heavy metal core coated with a soft outer layer. These engineered aggregates can be tuned so that particular frequencies of a propagating blast wave will activate resonant oscillations of the heavy mass within the inclusions. The resonant behavior causes the system to exhibit negative effective mass, and this interaction between the wave motion and the resonant aggregates results in the attenuation of the applied dynamic loading. We introduce the concept of negative mass by deriving the effective momentum mass for the system and we define the geometrical and material parameters for the design of resonant aggregates. We develop finite element models for the analysis of metaconcrete behavior, defining a section of slab containing a periodic arrangement of inclusions. By computing the energy histories for the system when subject to a blast load, we show that there is a transfer of energy between the inclusions and the surrounding mortar. The inclusions are able to absorb a significant portion of the applied energy, resulting in a reduction in the amount of stress carried by the mortar phase and greatly improving the ability of the material to resist damage under explosive dynamic loading.

  2. Design geometry and design/off-design performance computer codes for compressors and turbines

    NASA Technical Reports Server (NTRS)

    Glassman, Arthur J.

    1995-01-01

    This report summarizes some NASA Lewis (i.e., government owned) computer codes capable of being used for airbreathing propulsion system studies to determine the design geometry and to predict the design/off-design performance of compressors and turbines. These are not CFD codes; velocity-diagram energy and continuity computations are performed fore and aft of the blade rows using meanline, spanline, or streamline analyses. Losses are provided by empirical methods. Both axial-flow and radial-flow configurations are included.

  3. Design and performance of duct acoustic treatment

    NASA Technical Reports Server (NTRS)

    Motsinger, R. E.; Kraft, R. E.

    1991-01-01

    The procedure for designing acoustic treatment panels used to line the walls of aircraft engine ducts and for estimating the resulting suppression of turbofan engine duct noise is discussed. This procedure is intended to be used for estimating noise suppression of existing designs or for designing new acoustic treatment panels and duct configurations to achieve desired suppression levels.

  4. Design and Implementation of an Object Oriented Learning Activity System

    ERIC Educational Resources Information Center

    Lin, Huan-Yu; Tseng, Shian-Shyong; Weng, Jui-Feng; Su, Jun-Ming

    2009-01-01

    With the development of e-learning technology, many specifications of instructional design have been proposed to make learning activity sharable and reusable. With the specifications and sufficient learning resources, the researches further focus on how to provide learners more appropriate learning activities to improve their learning performance.…

  5. Physical Activity Design Guidelines for School Architecture

    PubMed Central

    Brittin, Jeri; Sorensen, Dina; Trowbridge, Matthew; Lee, Karen K.; Breithecker, Dieter; Frerichs, Leah; Huang, Terry

    2015-01-01

    Increasing children’s physical activity at school is a national focus in the U.S. to address childhood obesity. While research has demonstrated associations between aspects of school environments and students’ physical activity, the literature currently lacks a synthesis of evidence to serve as a practical, spatially-organized resource for school designers and decision-makers, as well as to point to pertinent research opportunities. This paper describes the development of a new practical tool: Physical Activity Design Guidelines for School Architecture. Its aims are to provide architects and designers, as well as school planners, educators, and public health professionals, with strategies for making K-12 school environments conducive to healthy physical activity, and to engage scientists in transdisciplinary perspectives toward improved knowledge of the school environment’s impact. We used a qualitative review process to develop evidence-based and theory-driven school design guidelines that promote increased physical activity among students. The design guidelines include specific strategies in 10 school design domains. Implementation of the guidelines is expected to enable students to adopt healthier physical activity behaviors. The tool bridges a translational gap between research and environmental design practice, and may contribute to setting new industry and education standards. PMID:26230850

  6. Physical Activity Design Guidelines for School Architecture.

    PubMed

    Brittin, Jeri; Sorensen, Dina; Trowbridge, Matthew; Lee, Karen K; Breithecker, Dieter; Frerichs, Leah; Huang, Terry

    2015-01-01

    Increasing children's physical activity at school is a national focus in the U.S. to address childhood obesity. While research has demonstrated associations between aspects of school environments and students' physical activity, the literature currently lacks a synthesis of evidence to serve as a practical, spatially-organized resource for school designers and decision-makers, as well as to point to pertinent research opportunities. This paper describes the development of a new practical tool: Physical Activity Design Guidelines for School Architecture. Its aims are to provide architects and designers, as well as school planners, educators, and public health professionals, with strategies for making K-12 school environments conducive to healthy physical activity, and to engage scientists in transdisciplinary perspectives toward improved knowledge of the school environment's impact. We used a qualitative review process to develop evidence-based and theory-driven school design guidelines that promote increased physical activity among students. The design guidelines include specific strategies in 10 school design domains. Implementation of the guidelines is expected to enable students to adopt healthier physical activity behaviors. The tool bridges a translational gap between research and environmental design practice, and may contribute to setting new industry and education standards. PMID:26230850

  7. Physical Activity Design Guidelines for School Architecture.

    PubMed

    Brittin, Jeri; Sorensen, Dina; Trowbridge, Matthew; Lee, Karen K; Breithecker, Dieter; Frerichs, Leah; Huang, Terry

    2015-01-01

    Increasing children's physical activity at school is a national focus in the U.S. to address childhood obesity. While research has demonstrated associations between aspects of school environments and students' physical activity, the literature currently lacks a synthesis of evidence to serve as a practical, spatially-organized resource for school designers and decision-makers, as well as to point to pertinent research opportunities. This paper describes the development of a new practical tool: Physical Activity Design Guidelines for School Architecture. Its aims are to provide architects and designers, as well as school planners, educators, and public health professionals, with strategies for making K-12 school environments conducive to healthy physical activity, and to engage scientists in transdisciplinary perspectives toward improved knowledge of the school environment's impact. We used a qualitative review process to develop evidence-based and theory-driven school design guidelines that promote increased physical activity among students. The design guidelines include specific strategies in 10 school design domains. Implementation of the guidelines is expected to enable students to adopt healthier physical activity behaviors. The tool bridges a translational gap between research and environmental design practice, and may contribute to setting new industry and education standards.

  8. Designing High Performance Schools (CD-ROM)

    SciTech Connect

    Not Available

    2002-10-01

    The EnergySmart Schools Design Guidelines and Best Practices Manual were written as a part of the EnergySmart Schools suite of documents, provided by the US Department of Energy, to educate school districts around the country about energy efficiency and renewable energy. Written for school administrators, design teams, and architects and engineers, the documents are designed to help those who are responsible for designing or retrofitting schools, as well as their project managers. This manual will help design staff make informed decisions about energy and environmental issues important to the school systems and communities.

  9. Designing Electronic Performance Support Systems: Models and Instructional Strategies Employed

    ERIC Educational Resources Information Center

    Nekvinda, Christopher D.

    2011-01-01

    The purpose of this qualitative study was to determine whether instructional designers and performance technologists utilize instructional design models when designing and developing electronic performance support systems (EPSS). The study also explored if these same designers were utilizing instructional strategies within their EPSS to support…

  10. DESIGN CONSIDERATION INVOLVING ACTIVE SEDIMENT CAPS

    EPA Science Inventory

    When contaminated sediments pose unacceptable risks to human health and the environment, management activities such as removal, treatment, or isolation of contaminated sediments may be required. Various capping designs are being considered for isolating contaminated sediment are...

  11. DESIGN CONSIDERATION INVOLVING ACTIVE SEDIMENT CAPS (PRESENTATION)

    EPA Science Inventory

    When contaminated sediments pose unacceptable risks to human health and the environment, management activities such as removal, treatment, or isolation of contaminated sediments may be required. Various capping designs are being considered for isolating contaminated sediment are...

  12. Active Learning through Toy Design and Development

    ERIC Educational Resources Information Center

    Sirinterlikci, Arif; Zane, Linda; Sirinterlikci, Aleea L.

    2009-01-01

    This article presents an initiative that is based on active learning pedagogy by engaging elementary and middle school students in the toy design and development field. The case study presented in this article is about student learning experiences during their participation in the TOYchallenge National Toy Design Competition. Students followed the…

  13. Karyotype Analysis Activity: A Constructivist Learning Design

    ERIC Educational Resources Information Center

    Ahmed, Noveera T.

    2015-01-01

    This classroom activity is based on a constructivist learning design and engages students in physically constructing a karyotype of three mock patients. Students then diagnose the chromosomal aneuploidy based on the karyotype, list the symptoms associated with the disorder, and discuss the implications of the diagnosis. This activity is targeted…

  14. Fastrac Nozzle Design, Performance and Development

    NASA Technical Reports Server (NTRS)

    Peters, Warren; Rogers, Pat; Lawrence, Tim; Davis, Darrell; DAgostino, Mark; Brown, Andy

    2000-01-01

    With the goal of lowering the cost of payload to orbit, NASA/MSFC (Marshall Space Flight Center) researched ways to decrease the complexity and cost of an engine system and its components for a small two-stage booster vehicle. The composite nozzle for this Fastrac Engine was designed, built and tested by MSFC with fabrication support and engineering from Thiokol-SEHO (Science and Engineering Huntsville Operation). The Fastrac nozzle uses materials, fabrication processes and design features that are inexpensive, simple and easily manufactured. As the low cost nozzle (and injector) design matured through the subscale tests and into full scale hot fire testing, X-34 chose the Fastrac engine for the propulsion plant for the X-34. Modifications were made to nozzle design in order to meet the new flight requirements. The nozzle design has evolved through subscale testing and manufacturing demonstrations to full CFD (Computational Fluid Dynamics), thermal, thermomechanical and dynamic analysis and the required component and engine system tests to validate the design. The Fastrac nozzle is now in final development hot fire testing and has successfully accumulated 66 hot fire tests and 1804 seconds on 18 different nozzles.

  15. Nuclear design of a very-low-activation fusion reactor

    SciTech Connect

    Cheng, E.T.; Hopkins, G.R.

    1983-06-01

    An investigation was conducted to study the nuclear design aspects of using very-low-activation materials, such as SiC, MgO, and aluminum for fusion-reactor first wall, blanket, and shield applications. In addition to the advantage of very-low radioactive inventory, it was found that the very-low-activation fusion reactor can also offer an adequate tritium-breeding ratio and substantial amount of blanket nuclear heating as a conventional-material-structured reactor does. The most-stringent design constraint found in a very-low-activation fusion reactor is the limited space available in the inboard region of a tokamak concept for shielding to protect the superconducting toroidal field coil. A reference design was developed which mitigates the constraint by adopting a removable tungsten shield design that retains the inboard dimensions and gives the same shield performance as the reference STARFIRE tokamak reactor design.

  16. Industry activities to improve valve performance

    SciTech Connect

    Callaway, C.

    1996-12-01

    Motor-operated valve issues refuse to go away. For over a decade the industry and the NRC have been focusing extraordinary resources on assuring these special components operate when called upon. Now that industry has fixed the design deficiencies, it is focusing on assuring that they perform their safety function within the current licensing basis for the remainder of plant life. NEI supported the efforts by ASME to develop OMN-1 and was encouraged that the industry and the NRC worked together to develop risk and performance based approaches to maintain MOV performance.

  17. Fostering Teachers' Design Expertise in Teacher Design Teams: Conducive Design and Support Activities

    ERIC Educational Resources Information Center

    Huizinga, Tjark; Handelzalts, Adam; Nieveen, Nienke; Voogt, Joke

    2015-01-01

    Supporting Teacher Design Teams (TDTs) during local curriculum development efforts is essential. To be able to provide high-quality support, insights are needed about how TDTs carry out design activities and how support is valued by the members of TDTs and how it affects their design expertise. In this study, the design and support processes of…

  18. Designing High Performance Schools through Instructional Supervision.

    ERIC Educational Resources Information Center

    Duffy, Francis M.

    This paper summarizes a new paradigm of instructional supervision, which shifts the focus from individual behavior to the improvement of work processes and social system components of the school district. The proposed paradigm, the Knowledge Work Supervision model, is derived from sociotechnical systems design theory and linked to the premise that…

  19. The design and performance of the research reactor fuel counter

    SciTech Connect

    Abhold, M.E.; Hsue, S.T.; Menlove, H.O.; Walton, G.; Holt, S.

    1996-09-01

    This paper describes the design features, hardware specifications, and performance characteristics of the Research Reactor Fuel Counter (RRFC) System. The system is an active mode neutron coincidence counter intended to assay material test reactor fuel assemblies under water. The RRFC contains 12 {sup 3}He tubes, each with its own preamplifier, and a single ion chamber. The neutron counting electronics are based on the Los Alamos Portable Shift Register (PSR) and the gamma readout is a manual-range pico-ammeter of Los Alamos design. The RRFC is connected to the surface by a 20-m-long cable bundle. The PSR is controlled by a portable IBM computer running a modified version of the Los Alamos neutron coincidence counting code also called RRFC. There is a manual that describes the RRFC software.

  20. Participatory Design Activities and Agile Software Development

    NASA Astrophysics Data System (ADS)

    Kautz, Karlheinz

    This paper contributes to the studies of design activities in information systems development. It provides a case study of a large agile development project and focusses on how customers and users participated in agile development and design activities in practice. The investigated project utilized the agile method eXtreme Programming. Planning games, user stories and story cards, working software, and acceptance tests structured the customer and user involvement. We found genuine customer and user involvement in the design activities in the form of both direct and indirect participation in the agile development project. The involved customer representatives played informative, consultative, and participative roles in the project. This led to their functional empowerment— the users were enabled to carry out their work to their own satisfaction and in an effective, efficient, and economical manner.

  1. Design Considerations and Performance of MEMS Acoustoelectric Ultrasound Detectors

    PubMed Central

    Wang, Zhaohui; Ingram, Pier; Greenlee, Charles L.; Olafsson, Ragnar; Norwood, Robert A.; Witte, Russell S.

    2014-01-01

    Most single-element hydrophones depend on a piezoelectric material that converts pressure changes to electricity. These devices, however, can be expensive, susceptible to damage at high pressure, and/or have limited bandwidth and sensitivity. We have previously described the acoustoelectric (AE) hydrophone as an inexpensive alternative for mapping an ultrasound beam and monitoring acoustic exposure. The device exploits the AE effect, an interaction between electrical current flowing through a material and a propagating pressure wave. Previous designs required imprecise fabrication methods using common laboratory supplies, making it difficult to control basic features such as shape and size. This study describes a different approach based on microelectromechanical systems (MEMS) processing that allows for much finer control of several design features. In an effort to improve the performance of the AE hydrophone, we combine simulations with bench-top testing to evaluate key design features, such as thickness, shape, and conductivity of the active and passive elements. The devices were evaluated in terms of sensitivity, frequency response, and accuracy for reproducing the beam pattern. Our simulations and experimental results both indicated that designs using a combination of indium tin oxide (ITO) for the active element and gold for the passive electrodes (conductivity ratio = ~20) produced the best result for mapping the beam of a 2.25-MHz ultrasound transducer. Also, the AE hydrophone with a rectangular dumbbell configuration achieved a better beam pattern than other shape configurations. Lateral and axial resolutions were consistent with images generated from a commercial capsule hydrophone. Sensitivity of the best-performing device was 1.52 nV/Pa at 500 kPa using a bias voltage of 20 V. We expect a thicker AE hydrophone closer to half the acoustic wavelength to produce even better sensitivity, while maintaining high spectral bandwidth for characterizing medical

  2. Coherent Lidar Design and Performance Verification

    NASA Technical Reports Server (NTRS)

    Frehlich, Rod

    1996-01-01

    This final report summarizes the investigative results from the 3 complete years of funding and corresponding publications are listed. The first year saw the verification of beam alignment for coherent Doppler lidar in space by using the surface return. The second year saw the analysis and computerized simulation of using heterodyne efficiency as an absolute measure of performance of coherent Doppler lidar. A new method was proposed to determine the estimation error for Doppler lidar wind measurements without the need for an independent wind measurement. Coherent Doppler lidar signal covariance, including wind shear and turbulence, was derived and calculated for typical atmospheric conditions. The effects of wind turbulence defined by Kolmogorov spatial statistics were investigated theoretically and with simulations. The third year saw the performance of coherent Doppler lidar in the weak signal regime determined by computer simulations using the best velocity estimators. Improved algorithms for extracting the performance of velocity estimators with wind turbulence included were also produced.

  3. Energy Design Guidelines for High Performance Schools: Tropical Island Climates

    SciTech Connect

    2004-11-01

    Design guidelines outline high performance principles for the new or retrofit design of K-12 schools in tropical island climates. By incorporating energy improvements into construction or renovation plans, schools can reduce energy consumption and costs.

  4. Network interface unit design options performance analysis

    NASA Technical Reports Server (NTRS)

    Miller, Frank W.

    1991-01-01

    An analysis is presented of three design options for the Space Station Freedom (SSF) onboard Data Management System (DMS) Network Interface Unit (NIU). The NIU provides the interface from the Fiber Distributed Data Interface (FDDI) local area network (LAN) to the DMS processing elements. The FDDI LAN provides the primary means for command and control and low and medium rate telemetry data transfers on board the SSF. The results of this analysis provide the basis for the implementation of the NIU.

  5. Differentiator design and performance for edge sharpening

    USGS Publications Warehouse

    Pan, Jeng-Jong; Domingue, Julia O.

    1990-01-01

    A two-dimensional differentiator is useful for edge sharpening in digital image processing. In the design of a differentiator, differentiator coefficients that satisfy the specification of frequency response must be approximated. Four mathematical techniques - the minimax method, least-squares method, nonlinear programming, and linear programming - can be applied to solve the approximation problem. Results indicated that the differentiator derived from linear programming gives the highest resolution. -from Authors

  6. 3MI OPD optical design: concept and performances

    NASA Astrophysics Data System (ADS)

    Gabrieli, Riccardo; Bartoli, Alessandro; Maiorano, Michele; Bruno, Umberto; Belli, Fabio; Bove, Giuseppe; Caruso, Alberto; Calamai, Luciano; Manolis, Ilias; Labate, Demetrio

    2015-09-01

    The Multi-Viewing, Multi-Channel, Multi-Polarisation Imager (3MI) is an imaging radiometer for the ESA/Eumetsat MetOp-SG programme. Based on the heritage of POLDER/PARASOL, 3MI will collect global observations of the top-of-atmosphere polarised bi-directional reflectance distribution function in 12 spectral bands, by observing the same target from multiple views using a push-broom scanning concept. In order to mitigate any technological risks associated with the 3MI instrument development, an Elegant Breadboard of representative form, function and performance to the 3MI VNIR lens was foreseen in the frame of the Optics Pre- Development (OPD) activity. The optical design and the performance results of the OPD VNIR lens are presented, from the top level requirements flow-down to the optical design solution and concept adopted. The large FOV and image irradiance uniformity, the extended VNIR spectral range, combined with the demanding polarisation and stray-light requirements are the main design drivers. The design concept is based on a Galilean telescope coupled to a focusing group. The aperture stop, placed in between, is located in such a way that the system is telecentric in image space. The system exhibits a fine control of the entrance pupil size as a function of the FOV, low distortion and correction of lateral chromatic aberration. Polarisation related performances are achieved by low polarisation sensitivity and low retardance anti-reflection coatings, as well as by a proper selection of glass material properties.

  7. Performance Evaluation Gravity Probe B Design

    NASA Technical Reports Server (NTRS)

    Francis, Ronnie; Wells, Eugene M.

    1996-01-01

    This final report documents the work done to develop a 6 degree-of-freedom simulation of the Lockheed Martin Gravity Probe B (GPB) Spacecraft. This simulation includes the effects of vehicle flexibility and propellant slosh. The simulation was used to investigate the control performance of the spacecraft when subjected to realistic on orbit disturbances.

  8. Designing Performance Interventions for the Information Age

    ERIC Educational Resources Information Center

    Schatz, Steven; Schwen, Thomas M.

    2006-01-01

    Dynamic Online Performance Support Systems (DOPSS) are a new class of intervention that can meet the needs of a quickly changing work force in an information age environment. These systems are customized for the target population, with unique meta tags, unique function sets, and dynamic growth for and by users in use. These unique tag sets allow…

  9. Design and performance of nitride-based ultraviolet (UV) LEDs

    SciTech Connect

    CRAWFORD,MARY H.; HAN,JUNG

    2000-04-24

    The authors overview several of the challenges in achieving high efficiency nitride-based UV (< 400 nm) LEDs. The issue of optical efficiency is presented through temperature-dependent photoluminescence studies of various UV active regions. These studies demonstrate enhanced optical efficiencies for active regions with In-containing alloys (InGaN, AlInGaN). The authors compare the performance of two distinct UV LED structures. GaN/AlGaN quantum well LEDs with {lambda} < 360 nm emission have demonstrated output powers > 0.1 mW, but present designs suffer from internal absorption effects. InGaN/AlInGaN quantum well LEDs with 370 nm < {lambda} < 390 nm emission and > 1 mW output power are also presented.

  10. Swimming and other activities: applied aspects of fish swimming performance

    USGS Publications Warehouse

    Castro-Santos, Theodore R.; Farrell, A.P.

    2011-01-01

    Human activities such as hydropower development, water withdrawals, and commercial fisheries often put fish species at risk. Engineered solutions designed to protect species or their life stages are frequently based on assumptions about swimming performance and behaviors. In many cases, however, the appropriate data to support these designs are either unavailable or misapplied. This article provides an overview of the state of knowledge of fish swimming performance – where the data come from and how they are applied – identifying both gaps in knowledge and common errors in application, with guidance on how to avoid repeating mistakes, as well as suggestions for further study.

  11. Business Performer-Centered Design of User Interfaces

    NASA Astrophysics Data System (ADS)

    Sousa, Kênia; Vanderdonckt, Jean

    Business Performer-Centered Design of User Interfaces is a new design methodology that adopts business process (BP) definition and a business performer perspective for managing the life cycle of user interfaces of enterprise systems. In this methodology, when the organization has a business process culture, the business processes of an organization are firstly defined according to a traditional methodology for this kind of artifact. These business processes are then transformed into a series of task models that represent the interactive parts of the business processes that will ultimately lead to interactive systems. When the organization has its enterprise systems, but not yet its business processes modeled, the user interfaces of the systems help derive tasks models, which are then used to derive the business processes. The double linking between a business process and a task model, and between a task model and a user interface model makes it possible to ensure traceability of the artifacts in multiple paths and enables a more active participation of business performers in analyzing the resulting user interfaces. In this paper, we outline how a human-perspective is used tied to a model-driven perspective.

  12. ACCESS: Design and Sub-System Performance

    NASA Technical Reports Server (NTRS)

    Kaiser, Mary Elizabeth; Morris, Matthew J.; McCandliss, Stephan R.; Rasucher, Bernard J.; Kimble, Randy A.; Kruk, Jeffrey W.; Pelton, Russell; Mott, D. Brent; Wen, Hiting; Foltz, Roger; Quijada, Manuel A.; Gum, Jeffery S.; Gardner, Jonathan P.; Kahle, Duncan M.; Benford, Dominic J.; Woodgate, Bruce E.; Wright, Edward L.; Feldman, Paul D.; Hart, Murdock; Moos, H. Warren; Reiss, Adam G.; Bohlin, Ralph; Deustua, Susana E.; Dixon, W. V.; Sahnow, David J.

    2012-01-01

    Establishing improved spectrophotometric standards is important for a broad range of missions and is relevant to many astrophysical problems. ACCESS, "Absolute Color Calibration Experiment for Standard Stars", is a series of rocket-borne sub-orbital missions and ground-based experiments designed to enable improvements in the precision of the astrophysical flux scale through the transfer of absolute laboratory detector standards from the National Institute of Standards and Technology (NIST) to a network of stellar standards with a calibration accuracy of 1% and a spectral resolving power of 500 across the 0.35 -1.7 micrometer bandpass.

  13. Extravehicular activities guidelines and design criteria

    NASA Technical Reports Server (NTRS)

    Brown, N. E.; Dashner, T. R.; Hayes, B. C.

    1973-01-01

    A listing of astronaut EVA support systems and equipment, and the physical, operational, and performance characteristics of each major system are presented. An overview of the major ground based support operations necessary in the development and verification of orbital EVA systems is included. The performance and biomedical characteristics of man in the orbital EV environment are discussed. Major factors affecting astronaut EV work performance are identified and delineated as they relate to EV support systems design. Data concerning the medical and physiological aspects of spaceflight on man are included. The document concludes with an extensive bibliography, and a series of appendices which expand on some of the information presented in the main body.

  14. Active damping performance of the KAGRA seismic attenuation system prototype

    NASA Astrophysics Data System (ADS)

    Fujii, Yoshinori; Sekiguchi, Takanori; Takahashi, Ryutaro; Aso, Yoichi; Barton, Mark; Erasmo Peña Arellano, Fabián; Shoda, Ayaka; Akutsu, Tomotada; Miyakawa, Osamu; Kamiizumi, Masahiro; Ishizaki, Hideharu; Tatsumi, Daisuke; Hirata, Naoatsu; Hayama, Kazuhiro; Okutomi, Koki; Miyamoto, Takahiro; Ishizuka, Hideki; DeSalvo, Riccardo; Flaminio, Raffaele

    2016-05-01

    The Large-scale Cryogenic Gravitational wave Telescope (formerly LCGT now KAGRA) is presently under construction in Japan. This May we assembled a prototype of the seismic attenuation system (SAS) for the beam splitter and the signal recycling mirrors of KAGRA, which we call Type-B SAS, and evaluated its performance at NAOJ (Mitaka, Toyko). We investigated its frequency response, active damping performance, vibration isolation performance and long-term stability both in and out of vacuum. From the frequency response test and the active damping performance test, we confirmed that the SAS worked as we designed and that all mechanical resonances which could disturb lock acquisition and observation are damped within 1 minute, which is required for KAGRA, by the active controls.

  15. Performance Evaluation Method for Dissimilar Aircraft Designs

    NASA Technical Reports Server (NTRS)

    Walker, H. J.

    1979-01-01

    A rationale is presented for using the square of the wingspan rather than the wing reference area as a basis for nondimensional comparisons of the aerodynamic and performance characteristics of aircraft that differ substantially in planform and loading. Working relationships are developed and illustrated through application to several categories of aircraft covering a range of Mach numbers from 0.60 to 2.00. For each application, direct comparisons of drag polars, lift-to-drag ratios, and maneuverability are shown for both nondimensional systems. The inaccuracies that may arise in the determination of aerodynamic efficiency based on reference area are noted. Span loading is introduced independently in comparing the combined effects of loading and aerodynamic efficiency on overall performance. Performance comparisons are made for the NACA research aircraft, lifting bodies, century-series fighter aircraft, F-111A aircraft with conventional and supercritical wings, and a group of supersonic aircraft including the B-58 and XB-70 bomber aircraft. An idealized configuration is included in each category to serve as a standard for comparing overall efficiency.

  16. Vehicle performance impact on space shuttle design and concept evaluation

    NASA Technical Reports Server (NTRS)

    Craig, M. K.

    1972-01-01

    The continuing examination of widely varied space shuttle concepts makes an understanding of concept interaction with vehicle performance imperative. The estimation of vehicle performance is highly appurtenant to all aspects of shuttle design and hence performance has classically been a key indicator of overall concept desirability and potential. Vehicle performance assumes the added role of defining interactions between specific design characteristics, the sum total of which define a specific concept. Special attention is given to external tank effects.

  17. Performance Trend of Different Algorithms for Structural Design Optimization

    NASA Technical Reports Server (NTRS)

    Patnaik, Surya N.; Coroneos, Rula M.; Guptill, James D.; Hopkins, Dale A.

    1996-01-01

    Nonlinear programming algorithms play an important role in structural design optimization. Fortunately, several algorithms with computer codes are available. At NASA Lewis Research Center, a project was initiated to assess performance of different optimizers through the development of a computer code CometBoards. This paper summarizes the conclusions of that research. CometBoards was employed to solve sets of small, medium and large structural problems, using different optimizers on a Cray-YMP8E/8128 computer. The reliability and efficiency of the optimizers were determined from the performance of these problems. For small problems, the performance of most of the optimizers could be considered adequate. For large problems however, three optimizers (two sequential quadratic programming routines, DNCONG of IMSL and SQP of IDESIGN, along with the sequential unconstrained minimizations technique SUMT) outperformed others. At optimum, most optimizers captured an identical number of active displacement and frequency constraints but the number of active stress constraints differed among the optimizers. This discrepancy can be attributed to singularity conditions in the optimization and the alleviation of this discrepancy can improve the efficiency of optimizers.

  18. An RC active filter design handbook

    NASA Technical Reports Server (NTRS)

    Deboo, G. J.

    1977-01-01

    The design of filters is described. Emphasis is placed on simplified procedures that can be used by the reader who has minimum knowledge about circuit design and little acquaintance with filter theory. The handbook has three main parts. The first part is a review of some information that is essential for work with filters. The second part includes design information for specific types of filter circuitry and describes simple procedures for obtaining the component values for a filter that will have a desired set of characteristics. Pertinent information relating to actual performance is given. The third part (appendix) is a review of certain topics in filter theory and is intended to provide some basic understanding of how filters are designed.

  19. Off-design performance analysis of MHD generator channels

    NASA Technical Reports Server (NTRS)

    Wilson, D. R.; Williams, T. S.

    1980-01-01

    A computer code for performing parametric design point calculations, and evaluating the off-design performance of MHD generators has been developed. The program is capable of analyzing Faraday, Hall, and DCW channels, including the effect of electrical shorting in the gas boundary layers and coal slag layers. Direct integration of the electrode voltage drops is included. The program can be run in either the design or off-design mode. Details of the computer code, together with results of a study of the design and off-design performance of the proposed ETF MHD generator are presented. Design point variations of pre-heat and stoichiometry were analyzed. The off-design study included variations in mass flow rate and oxygen enrichment.

  20. ESO Catalogue Facility Design and Performance

    NASA Astrophysics Data System (ADS)

    Moins, C.; Retzlaff, J.; Arnaboldi, M.; Zampieri, S.; Delmotte, N.; Forchí, V.; Klein Gebbinck, M.; Lockhart, J.; Micol, A.; Vera Sequeiros, I.; Bierwirth, T.; Peron, M.; Romaniello, M.; Suchar, D.

    2013-10-01

    The ESO Phase 3 Catalogue Facility provides investigators with the possibility to ingest catalogues resulting from ESO public surveys and large programs and to query and download their content according to positional and non-positional criteria. It relies on a chain of tools that covers the complete workflow from submission to validation and ingestion into the ESO archive and catalogue repository and a web application to browse and query catalogues. This repository consists of two components. One is a Sybase ASE relational database where catalogue meta-data are stored. The second one is a Sybase IQ data warehouse where the content of each catalogue is ingested in a specific table that returns all records matching a user's query. Spatial indexing has been implemented in Sybase IQ to speed up positional queries and relies on the Spherical Geometry Toolkit from the Johns Hopkins University which implements the Hierarchical Triangular Mesh (HTM) algorithm. It is based on a recursive decomposition of the celestial sphere in spherical triangles and the assignment of an index to each of them. It has been complemented with the use of optimized indexes on the non-positional columns that are likely to be frequently used as query constraints. First tests performed on catalogues such as 2MASS have confirmed that this approach provides a very good level of performance and a smooth user experience that are likely to facilitate the scientific exploitation of catalogues.

  1. High Selective Performance of Designed Antibacterial and Anticancer Peptide Amphiphiles.

    PubMed

    Chen, Cuixia; Chen, Yucan; Yang, Cheng; Zeng, Ping; Xu, Hai; Pan, Fang; Lu, Jian Ren

    2015-08-12

    Short designed peptide amphiphiles are attractive at killing bacteria and inhibiting cancer cell growth, and the flexibility in their structural design offers a great potential for improving their potency and biocompatibility to mammalian host cells. Amino acid sequences such as G(IIKK)nI-NH2 (n≥3) have been shown to be membrane lytic, but terminal amino acid modifications could impose a huge influence on their performance. We report in this work how terminal amino acid modifications to G(IIKK)3I-NH2 influence its α-helical structure, membrane penetrating ability, and selective actions against different cell types. Deletion of an N-terminal Gly or a C-terminal Ile did not affect their antibacterial activity much, an observation consistent with their binding behavior to negatively charged membrane lipid monolayers. However, the cytotoxicity against mammalian cells was much worsened by the N-terminal Gly deletion, consistent with an increase in its helical content. Despite little impact on the antibacterial activity of G(IIKK)3I-NH2, deletion of both terminal amino acids greatly reduced its antitumor activity. Cholesterol present in tumor cell membrane-mimic was thought to constrain (IIKK)3-NH2 from penetrating into the cancerous membranes, evident from its lowest surface physical activity at penetrating model lipid membranes. On the other hand, its low toxicity to normal mammalian cells and high antibacterial activity in vitro and in vivo made it an attractive antibacterial agent. Thus, terminal modifications can help rebalance the different interactions involved and are highly effective at manipulating their selective membrane responses.

  2. Active array design for FAME: Freeform Active Mirror Experiment

    NASA Astrophysics Data System (ADS)

    Jaskó, Attila; Aitink-Kroes, Gabby; Agócs, Tibor; Venema, Lars; Hugot, Emmanuel; Schnetler, Hermine; Bányai, Evelin

    2014-07-01

    In this paper a status report is given on the development of the FAME (Freeform Active Mirror Experiment) active array. Further information regarding this project can be found in the paper by Venema et al. (this conference). Freeform optics provide the opportunity to drastically reduce the complexity of the future optical instruments. In order to produce these non-axisymmetric freeform optics with up to 1 mm deviation from the best fit sphere, it is necessary to come up with new design and manufacturing methods. The way we would like to create novel freeform optics is by fine tuning a preformed high surface-quality thin mirror using an array which is actively controlled by actuators. In the following we introduce the tools deployed to create and assess the individual designs. The result is an active array having optimal number and lay-out of actuators.

  3. Optical designs for improved solar cell performance

    NASA Astrophysics Data System (ADS)

    Kosten, Emily Dell

    wavelengths. This approach has the potential for very high efficiencies, and excellent annual power production. Using a light-trapping filtered concentrator approach, we design filter elements and find an optimal design. Thus, this thesis explores silicon microwires, angle restriction, and spectral splitting as different optical approaches for improving the cost and efficiency of solar cells.

  4. Design of a Cognitive Tool to Enhance Problemsolving Performance

    ERIC Educational Resources Information Center

    Lee, Youngmin; Nelson, David

    2005-01-01

    The design of a cognitive tool to support problem-solving performance for external representation of knowledge is described. The limitations of conventional knowledge maps are analyzed in proposing the tool. The design principles and specifications are described. This tool is expected to enhance learners problem-solving performance by allowing…

  5. 24 CFR 902.11 - PHAS performance designation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ....S.C. 1437(d)(j)(4)). ... 24 Housing and Urban Development 4 2014-04-01 2014-04-01 false PHAS performance designation. 902... designated a high performer if it scores below the threshold established for any indicator. (2)...

  6. 24 CFR 902.11 - PHAS performance designation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ....S.C. 1437(d)(j)(4)). ... 24 Housing and Urban Development 4 2012-04-01 2012-04-01 false PHAS performance designation. 902... designated a high performer if it scores below the threshold established for any indicator. (2)...

  7. 24 CFR 902.11 - PHAS performance designation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ....S.C. 1437(d)(j)(4)). ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false PHAS performance designation. 902... designated a high performer if it scores below the threshold established for any indicator. (2)...

  8. 24 CFR 902.11 - PHAS performance designation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ....S.C. 1437(d)(j)(4)). ... 24 Housing and Urban Development 4 2013-04-01 2013-04-01 false PHAS performance designation. 902... designated a high performer if it scores below the threshold established for any indicator. (2)...

  9. Aerodynamic Design Study of an Advanced Active Twist Rotor

    NASA Technical Reports Server (NTRS)

    Sekula, Martin K.; Wilbur, Matthew L.; Yeager, William T., Jr.

    2003-01-01

    An Advanced Active Twist Rotor (AATR) is currently being developed by the U.S. Army Vehicle Technology Directorate at NASA Langley Research Center. As a part of this effort, an analytical study was conducted to determine the impact of blade geometry on active-twist performance and, based on those findings, propose a candidate aerodynamic design for the AATR. The process began by creating a baseline design which combined the dynamic design of the original Active Twist Rotor and the aerodynamic design of a high lift rotor concept. The baseline model was used to conduct a series of parametric studies to examine the effect of linear blade twist and blade tip sweep, droop, and taper on active-twist performance. Rotor power requirements and hub vibration were also examined at flight conditions ranging from hover to advance ratio = 0.40. A total of 108 candidate designs were analyzed using the second-generation version of the Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics (CAMRAD II) code. The study concluded that the vibration reduction capabilities of a rotor utilizing controlled, strain-induced twisting are enhanced through the incorporation of blade tip sweep, droop, and taper into the blade design, while they are degraded by increasing the nose-down linear blade twist. Based on the analysis of rotor power, hub vibration, and active-twist response, a candidate aerodynamic design for the AATR consisting of a blade with approximately 10 degrees of linear blade twist and a blade tip design with 30 degree sweep, 10 degree droop, and 2.5:1 taper ratio over the outer five percent of the blade is proposed.

  10. Design and Performance of Tree-Structured Vector Quantizers.

    ERIC Educational Resources Information Center

    Lin, Jianhua; Storer, James A.

    1994-01-01

    Describes the design of optimal tree-structured vector quantizers that minimize the expected distortion subject to cost functions related to storage cost, encoding rate, or quantization time. Since the optimal design problem is intractable in most cases, the performance of a general design heuristic based on successive partitioning is analyzed.…

  11. Design of nutrient removal activated sludge systems.

    PubMed

    Manga, J; Ferrer, J; Seco, A; Garcia-Usach, F

    2003-01-01

    A mechanistic mathematical model for nutrient and organic matter removal was used to describe the behavior of a nitrification denitrification enhanced biological phosphorus removal (NDEBPR) system. This model was implemented in a user-friendly software DESASS (design and simulation of activated sludge systems). A 484-L pilot plant was operated to verify the model results. The pilot plant was operated for three years over three different sludge ages. The validity of the model was confirmed with data from the pilot plant. Also, the utility of DESASS as a valuable tool for designing NDEBPR systems was confirmed.

  12. Design of nutrient removal activated sludge systems.

    PubMed

    Manga, J; Ferrer, J; Seco, A; Garcia-Usach, F

    2003-01-01

    A mechanistic mathematical model for nutrient and organic matter removal was used to describe the behavior of a nitrification denitrification enhanced biological phosphorus removal (NDEBPR) system. This model was implemented in a user-friendly software DESASS (design and simulation of activated sludge systems). A 484-L pilot plant was operated to verify the model results. The pilot plant was operated for three years over three different sludge ages. The validity of the model was confirmed with data from the pilot plant. Also, the utility of DESASS as a valuable tool for designing NDEBPR systems was confirmed. PMID:12906279

  13. INTERIOR DUCT SYSTEM DESIGN, CONSTRUCTION, AND PERFORMANCE

    SciTech Connect

    Janet E.R. Mcllvaine; David Beal; Philip Fairey

    2001-10-10

    fresh air inlet design. Improvements were implemented by the Texas builder and retested in July. Results showed a 36% reduction in duct leakage, significant enough to warrant the builder adopting the new sealing procedure.

  14. Local encoding of computationally designed enzyme activity

    PubMed Central

    Allert, Malin; Dwyer, Mary A.; Hellinga, Homme W.

    2007-01-01

    One aim of computational protein design is to introduce novel enzyme activity into proteins of known structure by predicting mutations that stabilize transition states. Previously we have shown that it is possible to introduce triose phosphate isomerase activity into the ribose-binding protein of Escherichia coli by constructing 17 mutations in the first two layers of residues that surround the wild-type ligand-binding site. Here we report that these mutations can be “transplanted” into a homologous ribose-binding protein, isolated from the hyperthermophilic bacterium Thermoanaerobacter tengcongensis, with retention of catalytic activity, substrate affinity, and reaction pH dependence. The observed 105–106-fold rate enhancement corresponds to 70% of the maximally known transition-state binding energy. The wild-type sequences in these two homologues are almost perfectly conserved in the vicinity of their ribose-binding sites, but diverge significantly at increasing distance from these sites. The results demonstrate that the computationally designed mutations are sufficient to encode the observed enzyme activity, that all the observed activity is locally encoded within the layer of residues directly in contact with the substrate, and that in this case at least 70% of transition state stabilization energy can be achieved using straightforward considerations of stereochemical complementarity between enzyme and reactants. PMID:17196220

  15. Multidisciplinary design optimization of mechatronic vehicles with active suspensions

    NASA Astrophysics Data System (ADS)

    He, Yuping; McPhee, John

    2005-05-01

    A multidisciplinary optimization method is applied to the design of mechatronic vehicles with active suspensions. The method is implemented in a GA-A'GEM-MATLAB simulation environment in such a way that the linear mechanical vehicle model is designed in a multibody dynamics software package, i.e. A'GEM, the controllers and estimators are constructed using linear quadratic Gaussian (LQG) method, and Kalman filter algorithm in Matlab, then the combined mechanical and control model is optimized simultaneously using a genetic algorithm (GA). The design variables include passive parameters and control parameters. In the numerical optimizations, both random and deterministic road inputs and both perfect measurement of full state variables and estimated limited state variables are considered. Optimization results show that the active suspension systems based on the multidisciplinary optimization method have better overall performance than those derived using conventional design methods with the LQG algorithm.

  16. Design and performance of nitride-based UV LEDs

    SciTech Connect

    CRAWFORD,MARY H.; HAN,JUNG; CHOW,WENG W.; BANAS,MICHAEL ANTHONY; FIGIEL,JEFFREY J.; ZHANG,LEI; SHUL,RANDY J.

    2000-02-16

    In this paper, the authors overview several of the critical materials growth, design and performance issues for nitride-based UV (< 400 nm) LEDs. The critical issue of optical efficiency is presented through temperature-dependent photoluminescence studies of various UV active regions. These studies demonstrate enhanced optical efficiencies for active regions with In-containing alloys (InGaN, AlInGaN). The authors discuss the trade-off between the challenging growth of high Al containing alloys (AlGaN, AlGaInN), and the need for sufficient carrier confinement in UV heterostructures. Carrier leakage for various composition AlGaN barriers is examined through a calculation of the total unconfined carrier density in the quantum well system. They compare the performance of two distinct UV LED structures: GaN/AlGaN quantum well LEDs for {lambda}< 360 nm emission, and InGaN/AlGaInN quantum well LEDs for 370 nm <{lambda}< 390 nm emission.

  17. Designing Liquid Rocket Engine Injectors for Performance, Stability, and Cost

    NASA Technical Reports Server (NTRS)

    Westra, Douglas G.; West, Jeffrey S.; Richardson, Brian R.; Tucker, Paul K.

    2014-01-01

    NASA is using computational fluid dynamics (CFD) simulations to lower the cost and increase the performance and stability of fuel injector designs for next-generation liquid rocket engines (LREs). The Loci-STREAM CFD code is used to simulate the complex combustion processes inside the LRE. These analyses enable efficient evaluation of the performance and stability characteristics of injector design concepts, while decreasing reliance on the costly test-fail-fix cycle of traditional design approaches. These injector simulations were recently employed as a key part of the design process for an Advanced Booster concept for NASA's heavy-lift Space Launch System (SLS).

  18. Design and Performance Data for 81 Ah FNC Cells

    NASA Technical Reports Server (NTRS)

    Cohen, F.; Anderman, Menahem

    1997-01-01

    Design and performance data for 81 Ah FNC cells are given. The conclusions are: that a sealed Ni-Cd cells are not limited to 50 Ah with the FNC design; energy densities of 40 Wh/kg in a conservative high Cd, high electrolyte design have been demonstrated; uniform ATP data and LEO cycling performance is being demonstrated; internal cell pressures remain low under all conditions; and no conditioning is necessary under any LEO profile; accelerated LEO cycling exhibits performance well beyond traditional space Ni-Cd cells.

  19. Optimization of an Active Twist Rotor Blade Planform for Improved Active Response and Forward Flight Performance

    NASA Technical Reports Server (NTRS)

    Sekula, Martin K; Wilbur, Matthew L.

    2014-01-01

    A study was conducted to identify the optimum blade tip planform for a model-scale active twist rotor. The analysis identified blade tip design traits which simultaneously reduce rotor power of an unactuated rotor while leveraging aeromechanical couplings to tailor the active response of the blade. Optimizing the blade tip planform for minimum rotor power in forward flight provided a 5 percent improvement in performance compared to a rectangular blade tip, but reduced the vibration control authority of active twist actuation by 75 percent. Optimizing for maximum blade twist response increased the vibration control authority by 50 percent compared to the rectangular blade tip, with little effect on performance. Combined response and power optimization resulted in a blade tip design which provided similar vibration control authority to the rectangular blade tip, but with a 3.4 percent improvement in rotor performance in forward flight.

  20. Designing an Active Target Test Projection Chamber

    NASA Astrophysics Data System (ADS)

    Koci, James; Tan Ahn Collaboration, Dr.; Nicolas Dixneuf Collaboration

    2015-10-01

    The development of instrumentation in nuclear physics is crucial for advancing our ability to measure the properties of exotic nuclei. One limitation of the use of exotic nuclei in experiment is their very low production intensities. Recently, detectors, called active-target dectectors, have been developed to address this issue. Active-target detectors use a gas medium to image charged-particle tracks that are emitted in nuclear reactions. Last semester, I designed a vacuum chamber to be used in developing Micro-Pattern Gas detectors that will upgrade the capabilities of an active-target detector called the Prototype AT-TPC. With the exterior of the chamber complete, I have now been using an electric field modeling program, Garfield, developed by CERN to design a field cage to be placed within the vacuum chamber. The field cage will be a box-like apparatus consisting of two parallel metal plates connected with a resistor chain and attached to wires wrapped between them. The cage will provide a uniform electric field within the chamber to drift electrons from nuclear reactions down to the detector in the bottom of the chamber. These signals are then amplified by a proportional counter, and the data is sent to a computer. For the long term, we would like to incorporate a Micro-Pattern Gas Detectors in the interior of the chamber and eventually use the AT-TPC to examine various nuclei. Dr. Ahn is my advising professor.

  1. Design requirements document for project W-465, immobilized low activity waste interim storage

    SciTech Connect

    Burbank, D.A.

    1997-01-27

    The scope of this design requirements document is to identify the functions and associated requirements that must be performed to accept, transport, handle, and store immobilized low-activity waste produced by the privatized Tank Waste Remediation System treatment contractors. The functional and performance requirements in this document provide the basis for the conceptual design of the Tank Waste Remediation System Immobilized low-activity waste interim storage facility project and provides traceability from the program level requirements to the project design activity.

  2. North Sea platform cathodic protection -- A performance vs design review

    SciTech Connect

    Ridd, B.R.; Queen, D.M.E.; Osvoll, H.; Bjornaas, F.

    1999-07-01

    Modern day cathodic protection (CP) design codes are typically highly conservative when compared with early CP system designs. Review of historical survey data from platforms in service for approximately 25 to 30 years illustrates the conservatism now employed when constructing new structures for installation in the North Sea. This paper illustrates this level of conservatism by reviewing the CP system performance of a gas gathering platform complex in the Southern North Sea and comparing the results of that review with present day design codes. The paper details the findings of a CP design review and ROV validation inspection to determine the present system status. The effect of combined impressed current and sacrificial anode systems is also illustrated. Finally a discussion on the definition and optimization of additional CP system requirements and future survey strategy to ensure protection is maintained to the anticipated end of field life is provided highlighting the cost benefits of basing retrofit designs on system performance rather than design theory.

  3. A statistical approach to electromigration design for high performance VLSI

    NASA Astrophysics Data System (ADS)

    Kitchin, John; Sriram, T. S.

    1998-01-01

    Statistical Electromigration Budgeting (J. Kitchin, 1995 Symposium on VLSI Circuits) or SEB is based on the concepts: (a) reliable design in VLSI means achieving a chip-level reliability goal and (b) electromigration degradation is inherently statistical in nature. The SEB methodology is reviewed along with results from recent high performance VLSI designs. Two SEB-based approaches for efficiently coupling metallization reliability statistics to design options are developed. Allowable-length-at-stress design rules communicate electromigration risk budget constraints to designers without the need for sophisticated CAD tools for chip-level interconnect analysis. Electromigration risk contours allow comparison of evolving metallization reliability statistics with design requirements having multiple frequency, temperature, and voltage options, a common need in high performance VLSI product development.

  4. Surfactant-activated lipase hybrid nanoflowers with enhanced enzymatic performance

    PubMed Central

    Cui, Jiandong; Zhao, Yamin; Liu, Ronglin; Zhong, Cheng; Jia, Shiru

    2016-01-01

    Increasing numbers of materials have been extensively used as platforms for enzyme immobilization to improve catalytic performance. However, activity of the most of the enzymes was declined after immobilization. Here, we develop a surfactant-activated lipase-inorganic flowerlike hybrid nanomaterials with rational design based on interfacial activation and self-assembly. The resulting surfactant-activated lipase-inorganic hybird nanoflower (activated hNF-lipase) exhibited 460% and 200% higher activity than native lipase and conventional lipase-inorganic hybird nanoflower (hNF-lipase). Furthermore, the activated hNF-lipase displayed good reusability due to its monodispersity and mechanical properties, and had excellent long-time stability. The superior catalytic performances were attributed to both the conformational modulation of surfactants and hierarchical structure of nanoflowers, which not only anchored lipases in an active form, but also decreased the enzyme-support negative interaction and mass-transfer limitations. This new biocatalytic system is promising to find widespread use in applications related to biomedicine, biosensor, and biodiesel. PMID:27297609

  5. The Effect of School Design on Student Performance

    ERIC Educational Resources Information Center

    Ariani, Mohsen Ghasemi; Mirdad, Fatemeh

    2016-01-01

    The present study aims at exploring the influence of school design on student performance. The participants consisted of 150 students who studied at two Iranian public school and private school in Mashhad City. School Design and Planning Laboratory (SDPL) model of Georgia University (and Tanner (2009)) was used as an appraisal indicator of school…

  6. Off-Design Performance of Radial-Inflow Turbines

    NASA Technical Reports Server (NTRS)

    Meitner, P. L.; Glassman, A. J.

    1986-01-01

    Computer code determines rotor exit flow from hub to tip. RTOD (Radial Turbine Off-Design), computes off-design performance of radial turbine by modeling flow with stator viscous and trailing-edge losses, and with vaneless space loss between stator and rotor, and with rotor incidence, viscous, clearance, trailing-edge, and disk friction losses.

  7. Shuttle passenger couch. [design and performance of engineering model

    NASA Technical Reports Server (NTRS)

    Rosener, A. A.; Stephenson, M. L.

    1974-01-01

    Conceptual design and fabrication of a full scale shuttle passenger couch engineering model are reported. The model was utilized to verify anthropometric dimensions, reach dimensions, ingress/egress, couch operation, storage space, restraint locations, and crew acceptability. These data were then incorported in the design of the passenger couch verification model that underwent performance tests.

  8. Active flutter suppression - Control system design and experimental validation

    NASA Technical Reports Server (NTRS)

    Waszak, Martin R.; Srinathkumar, S.

    1991-01-01

    The synthesis and experimental validation of an active flutter suppression controller for the Active Flexible Wing wind-tunnel model is presented. The design is accomplished with traditional root locus and Nyquist methods using interactive computer graphics tools and with extensive use of simulation-based analysis. The design approach uses a fundamental understanding of the flutter mechanism to formulate a simple controller structure to meet stringent design specifications. Experimentally, the flutter suppression controller succeeded in simultaneous suppression of two flutter modes, significantly increasing the flutter dynamic pressure despite errors in flutter dynamic pressure and flutter frequency in the mathematical model. The flutter suppression controller was also successfully operated in combination with a roll maneuver controller to perform flutter suppression during rapid rolling maneuvers.

  9. Micropulse water vapor differential absorption lidar: transmitter design and performance.

    PubMed

    Nehrir, Amin R; Repasky, Kevin S; Carlsten, John L

    2012-10-22

    An all diode-laser-based micropulse differential absorption lidar (DIAL) laser transmitter for tropospheric water vapor and aerosol profiling is presented. The micropulse DIAL (MPD) transmitter utilizes two continuous wave (cw) external cavity diode lasers (ECDL) to seed an actively pulsed, overdriven tapered semiconductor optical amplifier (TSOA). The MPD laser produces up to 7 watts of peak power over a 1 µs pulse duration (7 µJ) and a 10 kHz pulse repetition frequency. Spectral switching between the online and offline seed lasers is achieved on a 1Hz basis using a fiber optic switch to allow for more accurate sampling of the atmospheric volume between the online and offline laser shots. The high laser spectral purity of greater than 0.9996 coupled with the broad tunability of the laser transmitter will allow for accurate measurements of tropospheric water vapor in a wide range of geographic locations under varying atmospheric conditions. This paper describes the design and performance characteristics of a third generation MPD laser transmitter with enhanced laser performance over the previous generation DIAL system.

  10. Micropulse water vapor differential absorption lidar: transmitter design and performance.

    PubMed

    Nehrir, Amin R; Repasky, Kevin S; Carlsten, John L

    2012-10-22

    An all diode-laser-based micropulse differential absorption lidar (DIAL) laser transmitter for tropospheric water vapor and aerosol profiling is presented. The micropulse DIAL (MPD) transmitter utilizes two continuous wave (cw) external cavity diode lasers (ECDL) to seed an actively pulsed, overdriven tapered semiconductor optical amplifier (TSOA). The MPD laser produces up to 7 watts of peak power over a 1 µs pulse duration (7 µJ) and a 10 kHz pulse repetition frequency. Spectral switching between the online and offline seed lasers is achieved on a 1Hz basis using a fiber optic switch to allow for more accurate sampling of the atmospheric volume between the online and offline laser shots. The high laser spectral purity of greater than 0.9996 coupled with the broad tunability of the laser transmitter will allow for accurate measurements of tropospheric water vapor in a wide range of geographic locations under varying atmospheric conditions. This paper describes the design and performance characteristics of a third generation MPD laser transmitter with enhanced laser performance over the previous generation DIAL system. PMID:23187280

  11. Transitioning from conceptual design to construction performance specification

    NASA Astrophysics Data System (ADS)

    Jeffers, Paul; Warner, Mark; Craig, Simon; Hubbard, Robert; Marshall, Heather

    2012-09-01

    On successful completion of a conceptual design review by a funding agency or customer, there is a transition phase before construction contracts can be placed. The nature of this transition phase depends on the Project's approach to construction and the particular subsystem being considered. There are generically two approaches; project retention of design authority and issuance of build to print contracts, or issuance of subsystem performance specifications with controlled interfaces. This paper relates to the latter where a proof of concept (conceptual or reference design) is translated into performance based sub-system specifications for competitive tender. This translation is not a straightforward process and there are a number of different issues to consider in the process. This paper deals with primarily the Telescope mount and Enclosure subsystems. The main subjects considered in this paper are: • Typical status of design at Conceptual Design Review compared with the desired status of Specifications and Interface Control Documents at Request for Quotation. • Options for capture and tracking of system requirements flow down from science / operating requirements and sub-system requirements, and functional requirements derived from reference design. • Requirements that may come specifically from the contracting approach. • Methods for effective use of reference design work without compromising a performance based specification. • Management of project team's expectation relating to design. • Effects on cost estimates from reference design to actual. This paper is based on experience and lessons learned through this process on both the VISTA and the ATST projects.

  12. Planetary Suit Hip Bearing Model for Predicting Design vs. Performance

    NASA Technical Reports Server (NTRS)

    Cowley, Matthew S.; Margerum, Sarah; Harvil, Lauren; Rajulu, Sudhakar

    2011-01-01

    Designing a planetary suit is very complex and often requires difficult trade-offs between performance, cost, mass, and system complexity. In order to verifying that new suit designs meet requirements, full prototypes must eventually be built and tested with human subjects. Using computer models early in the design phase of new hardware development can be advantageous, allowing virtual prototyping to take place. Having easily modifiable models of the suit hard sections may reduce the time it takes to make changes to the hardware designs and then to understand their impact on suit and human performance. A virtual design environment gives designers the ability to think outside the box and exhaust design possibilities before building and testing physical prototypes with human subjects. Reductions in prototyping and testing may eventually reduce development costs. This study is an attempt to develop computer models of the hard components of the suit with known physical characteristics, supplemented with human subject performance data. Objectives: The primary objective was to develop an articulating solid model of the Mark III hip bearings to be used for evaluating suit design performance of the hip joint. Methods: Solid models of a planetary prototype (Mark III) suit s hip bearings and brief section were reverse-engineered from the prototype. The performance of the models was then compared by evaluating the mobility performance differences between the nominal hardware configuration and hardware modifications. This was accomplished by gathering data from specific suited tasks. Subjects performed maximum flexion and abduction tasks while in a nominal suit bearing configuration and in three off-nominal configurations. Performance data for the hip were recorded using state-of-the-art motion capture technology. Results: The results demonstrate that solid models of planetary suit hard segments for use as a performance design tool is feasible. From a general trend perspective

  13. Optical design and active optics methods in astronomy

    NASA Astrophysics Data System (ADS)

    Lemaitre, Gerard R.

    2013-03-01

    Optical designs for astronomy involve implementation of active optics and adaptive optics from X-ray to the infrared. Developments and results of active optics methods for telescopes, spectrographs and coronagraph planet finders are presented. The high accuracy and remarkable smoothness of surfaces generated by active optics methods also allow elaborating new optical design types with high aspheric and/or non-axisymmetric surfaces. Depending on the goal and performance requested for a deformable optical surface analytical investigations are carried out with one of the various facets of elasticity theory: small deformation thin plate theory, large deformation thin plate theory, shallow spherical shell theory, weakly conical shell theory. The resulting thickness distribution and associated bending force boundaries can be refined further with finite element analysis.

  14. Advances in Experiment Design for High Performance Aircraft

    NASA Technical Reports Server (NTRS)

    Morelli, Engene A.

    1998-01-01

    A general overview and summary of recent advances in experiment design for high performance aircraft is presented, along with results from flight tests. General theoretical background is included, with some discussion of various approaches to maneuver design. Flight test examples from the F-18 High Alpha Research Vehicle (HARV) are used to illustrate applications of the theory. Input forms are compared using Cramer-Rao bounds for the standard errors of estimated model parameters. Directions for future research in experiment design for high performance aircraft are identified.

  15. Energy Efficient Engine core design and performance report

    NASA Technical Reports Server (NTRS)

    Stearns, E. Marshall

    1982-01-01

    The Energy Efficient Engine (E3) is a NASA program to develop fuel saving technology for future large transport aircraft engines. Testing of the General Electric E3 core showed that the core component performance and core system performance necessary to meet the program goals can be achieved. The E3 core design and test results are described.

  16. Bayesian Optimal Interval Design: A Simple and Well-Performing Design for Phase I Oncology Trials.

    PubMed

    Yuan, Ying; Hess, Kenneth R; Hilsenbeck, Susan G; Gilbert, Mark R

    2016-09-01

    Despite more than two decades of publications that offer more innovative model-based designs, the classical 3 + 3 design remains the most dominant phase I trial design in practice. In this article, we introduce a new trial design, the Bayesian optimal interval (BOIN) design. The BOIN design is easy to implement in a way similar to the 3 + 3 design, but is more flexible for choosing the target toxicity rate and cohort size and yields a substantially better performance that is comparable with that of more complex model-based designs. The BOIN design contains the 3 + 3 design and the accelerated titration design as special cases, thus linking it to established phase I approaches. A numerical study shows that the BOIN design generally outperforms the 3 + 3 design and the modified toxicity probability interval (mTPI) design. The BOIN design is more likely than the 3 + 3 design to correctly select the MTD and allocate more patients to the MTD. Compared with the mTPI design, the BOIN design has a substantially lower risk of overdosing patients and generally a higher probability of correctly selecting the MTD. User-friendly software is freely available to facilitate the application of the BOIN design. Clin Cancer Res; 22(17); 4291-301. ©2016 AACR. PMID:27407096

  17. Bayesian Optimal Interval Design: A Simple and Well-Performing Design for Phase I Oncology Trials.

    PubMed

    Yuan, Ying; Hess, Kenneth R; Hilsenbeck, Susan G; Gilbert, Mark R

    2016-09-01

    Despite more than two decades of publications that offer more innovative model-based designs, the classical 3 + 3 design remains the most dominant phase I trial design in practice. In this article, we introduce a new trial design, the Bayesian optimal interval (BOIN) design. The BOIN design is easy to implement in a way similar to the 3 + 3 design, but is more flexible for choosing the target toxicity rate and cohort size and yields a substantially better performance that is comparable with that of more complex model-based designs. The BOIN design contains the 3 + 3 design and the accelerated titration design as special cases, thus linking it to established phase I approaches. A numerical study shows that the BOIN design generally outperforms the 3 + 3 design and the modified toxicity probability interval (mTPI) design. The BOIN design is more likely than the 3 + 3 design to correctly select the MTD and allocate more patients to the MTD. Compared with the mTPI design, the BOIN design has a substantially lower risk of overdosing patients and generally a higher probability of correctly selecting the MTD. User-friendly software is freely available to facilitate the application of the BOIN design. Clin Cancer Res; 22(17); 4291-301. ©2016 AACR.

  18. Distributed design tools: Mapping targeted design tools onto a Web-based distributed architecture for high-performance computing

    SciTech Connect

    Holmes, V.P.; Linebarger, J.M.; Miller, D.J.; Poore, C.A.

    1999-11-30

    Design Tools use a Web-based Java interface to guide a product designer through the design-to-analysis cycle for a specific, well-constrained design problem. When these Design Tools are mapped onto a Web-based distributed architecture for high-performance computing, the result is a family of Distributed Design Tools (DDTs). The software components that enable this mapping consist of a Task Sequencer, a generic Script Execution Service, and the storage of both data and metadata in an active, object-oriented database called the Product Database Operator (PDO). The benefits of DDTs include improved security, reliability, scalability (in both problem size and computing hardware), robustness, and reusability. In addition, access to the PDO unlocks its wide range of services for distributed components, such as lookup and launch capability, persistent shared memory for communication between cooperating services, state management, event notification, and archival of design-to-analysis session data.

  19. Total systems design analysis of high performance structures

    NASA Technical Reports Server (NTRS)

    Verderaime, V.

    1993-01-01

    Designer-control parameters were identified at interdiscipline interfaces to optimize structural systems performance and downstream development and operations with reliability and least life-cycle cost. Interface tasks and iterations are tracked through a matrix of performance disciplines integration versus manufacturing, verification, and operations interactions for a total system design analysis. Performance integration tasks include shapes, sizes, environments, and materials. Integrity integrating tasks are reliability and recurring structural costs. Significant interface designer control parameters were noted as shapes, dimensions, probability range factors, and cost. Structural failure concept is presented, and first-order reliability and deterministic methods, benefits, and limitations are discussed. A deterministic reliability technique combining benefits of both is proposed for static structures which is also timely and economically verifiable. Though launch vehicle environments were primarily considered, the system design process is applicable to any surface system using its own unique filed environments.

  20. Modelling and design of high performance indium phosphide solar cells

    NASA Technical Reports Server (NTRS)

    Rhoads, Sandra L.; Barnett, Allen M.

    1989-01-01

    A first principles pn junction device model has predicted new designs for high voltage, high efficiency InP solar cells. Measured InP material properties were applied and device parameters (thicknesses and doping) were adjusted to obtain optimal performance designs. Results indicate that p/n InP designs will provide higher voltages and higher energy conversion efficiencies than n/p structures. Improvements to n/p structures for increased efficiency are predicted. These new designs exploit the high absorption capabilities, relatively long diffusion lengths, and modest surface recombination velocities characteristic of InP. Predictions of performance indicate achievable open-circuit voltage values as high as 943 mV for InP and a practical maximum AM0 efficiency of 22.5 percent at 1 sun and 27 C. The details of the model, the optimal InP structure and the effect of individual parameter variations on device performance are presented.

  1. Supersonic civil airplane study and design: Performance and sonic boom

    NASA Technical Reports Server (NTRS)

    Cheung, Samson

    1995-01-01

    Since aircraft configuration plays an important role in aerodynamic performance and sonic boom shape, the configuration of the next generation supersonic civil transport has to be tailored to meet high aerodynamic performance and low sonic boom requirements. Computational fluid dynamics (CFD) can be used to design airplanes to meet these dual objectives. The work and results in this report are used to support NASA's High Speed Research Program (HSRP). CFD tools and techniques have been developed for general usages of sonic boom propagation study and aerodynamic design. Parallel to the research effort on sonic boom extrapolation, CFD flow solvers have been coupled with a numeric optimization tool to form a design package for aircraft configuration. This CFD optimization package has been applied to configuration design on a low-boom concept and an oblique all-wing concept. A nonlinear unconstrained optimizer for Parallel Virtual Machine has been developed for aerodynamic design and study.

  2. Design readiness: An exploratory model of object-oriented design performance

    NASA Astrophysics Data System (ADS)

    Lewis, Tracy L.

    The available literature supports the fact that some students experience difficulty learning object-oriented design (OOD) principles. Previously explored predictors of OOD learning difficulties include student characteristics (cognitive activities, self-efficacy), teaching methodologies (teacher centered, course complexity), and student experiences (prior programming experience). Yet, within an extensive body of literature devoted to OOD, two explanations of student difficulty remain largely unexplored: (1) varying conceptualizations of the underlying principles/strategies of OOD, and (2) preparedness or readiness to learn OOD. This research also investigated the extent to which individual differences impacted DRAS and OOD performance. The individual difference measures of interest in this study included college grade point average, prior programming experience, cognitive abilities (spatial orientation, visualization, logical reasoning, flexibility, perceptual style), and design readiness. In addition, OOD performance was measured using two constructs: course grade (exams, labs, programs, overall), and a specially constructed design task. Participants selected from the CS2 course from two southeastern state universities were used within this study, resulting in a sample size of 161 (School A, n = 76; School B, n = 85). School A is a mid-sized comprehensive university and School B is a large research-intensive university. If was found that the schools significantly differed on all measures of prior computer science experience and cognitive abilities. Path analysis was conducted to determine which individual differences were related to design readiness and OOD performance. In summary, this research identified that instructors can not ignore individual differences when teaching OOD. It was found that the cognitive ability visualization, prior OO experience, and overall college grade point average should be considered when teaching OOD. As it stands, without

  3. Hanford immobilized low-activity tank waste performance assessment

    SciTech Connect

    Mann, F.M.

    1998-03-26

    The Hanford Immobilized Low-Activity Tank Waste Performance Assessment examines the long-term environmental and human health effects associated with the planned disposal of the vitrified low-level fraction of waste presently contained in Hanford Site tanks. The tank waste is the by-product of separating special nuclear materials from irradiated nuclear fuels over the past 50 years. This waste has been stored in underground single and double-shell tanks. The tank waste is to be retrieved, separated into low and high-activity fractions, and then immobilized by private vendors. The US Department of Energy (DOE) will receive the vitrified waste from private vendors and plans to dispose of the low-activity fraction in the Hanford Site 200 East Area. The high-level fraction will be stored at Hanford until a national repository is approved. This report provides the site-specific long-term environmental information needed by the DOE to issue a Disposal Authorization Statement that would allow the modification of the four existing concrete disposal vaults to provide better access for emplacement of the immobilized low-activity waste (ILAW) containers; filling of the modified vaults with the approximately 5,000 ILAW containers and filler material with the intent to dispose of the containers; construction of the first set of next-generation disposal facilities. The performance assessment activity will continue beyond this assessment. The activity will collect additional data on the geotechnical features of the disposal sites, the disposal facility design and construction, and the long-term performance of the waste. Better estimates of long-term performance will be produced and reviewed on a regular basis. Performance assessments supporting closure of filled facilities will be issued seeking approval of those actions necessary to conclude active disposal facility operations. This report also analyzes the long-term performance of the currently planned disposal system as a basis

  4. Design and performance oof space station photovoltaic radiators

    NASA Technical Reports Server (NTRS)

    White, K. Alan; Fleming, Mike L.; Lee, Avis Y.

    1993-01-01

    The design and performance of the Space Station Freedom Photovoltaic (PV) Power Module Thermal Control System radiators is presented. The PV Radiator is of a single phase pumped loop design using liquid ammonia as the coolant. Key design features are described, including the base structure, deployment mechanism, radiator panels, and two independent coolant loops. The basis for a specific mass of 7.8 kg/sqm is discussed, and methods of lowering this number for future systems are briefly described. Key performance paramters are also addressed. A summary of test results and analysis is presented to illustrate the survivability of the radiator in the micrometeoroid and orbital debris environment. A design criterion of 95% probability of no penetration of both fluid loops over a 10 year period is shown to be met. Methods of increasing the radiator survivability even further are presented. Thermal performance is also discussed, including a comparison of modeling predictions with existing test results. Degradation in thermal performance due to exposure to atomic oxygen and ultraviolet radiation in the low Earth orbit environment is presented. The structural criteria to which the radiator is designed are also briefly addressed. Finally, potential design improvements are discussed.

  5. Robust Multivariable Optimization and Performance Simulation for ASIC Design

    NASA Technical Reports Server (NTRS)

    DuMonthier, Jeffrey; Suarez, George

    2013-01-01

    Application-specific-integrated-circuit (ASIC) design for space applications involves multiple challenges of maximizing performance, minimizing power, and ensuring reliable operation in extreme environments. This is a complex multidimensional optimization problem, which must be solved early in the development cycle of a system due to the time required for testing and qualification severely limiting opportunities to modify and iterate. Manual design techniques, which generally involve simulation at one or a small number of corners with a very limited set of simultaneously variable parameters in order to make the problem tractable, are inefficient and not guaranteed to achieve the best possible results within the performance envelope defined by the process and environmental requirements. What is required is a means to automate design parameter variation, allow the designer to specify operational constraints and performance goals, and to analyze the results in a way that facilitates identifying the tradeoffs defining the performance envelope over the full set of process and environmental corner cases. The system developed by the Mixed Signal ASIC Group (MSAG) at the Goddard Space Flight Center is implemented as a framework of software modules, templates, and function libraries. It integrates CAD tools and a mathematical computing environment, and can be customized for new circuit designs with only a modest amount of effort as most common tasks are already encapsulated. Customization is required for simulation test benches to determine performance metrics and for cost function computation.

  6. Design method of water jet pump towards high cavitation performances

    NASA Astrophysics Data System (ADS)

    Cao, L. L.; Che, B. X.; Hu, L. J.; Wu, D. Z.

    2016-05-01

    As one of the crucial components for power supply, the propulsion system is of great significance to the advance speed, noise performances, stabilities and other associated critical performances of underwater vehicles. Developing towards much higher advance speed, the underwater vehicles make more critical demands on the performances of the propulsion system. Basically, the increased advance speed requires the significantly raised rotation speed of the propulsion system, which would result in the deteriorated cavitation performances and consequently limit the thrust and efficiency of the whole system. Compared with the traditional propeller, the water jet pump offers more favourite cavitation, propulsion efficiency and other associated performances. The present research focuses on the cavitation performances of the waterjet pump blade profile in expectation of enlarging its advantages in high-speed vehicle propulsion. Based on the specifications of a certain underwater vehicle, the design method of the waterjet blade with high cavitation performances was investigated in terms of numerical simulation.

  7. Correlation of mid-infrared quantum-cascade laser performance with laser design parameters

    NASA Astrophysics Data System (ADS)

    Leavitt, R. P.; Bradshaw, J. L.; Lascola, K. M.; Towner, F. J.; Pham, J. T.; Bruno, J. D.; Gmachl, C. F.; Liu, P. Q.

    2012-06-01

    Several different quantum-cascade (QC) laser designs spanning the wavelength range between ~3.8 and ~4.8 microns were grown, and devices were fabricated and tested. The active regions of these designs consist of strained layers of (In,Ga)As and (In,Al)As. For several of these designs, we varied design parameters including injector doping, sectioncoupling strength, and the number of QC laser periods. Lasers were tested near room temperature under both quasi-cw and low-duty-cycle conditions. Device performance is compared with theoretical expectations, and conclusions are reached on the relative merit of various design modifications.

  8. Some design considerations for high-performance infrared imaging seeker

    NASA Astrophysics Data System (ADS)

    Fan, Jinxiang; Huang, Jianxiong

    2015-10-01

    In recent years, precision guided weapons play more and more important role in modern war. The development and applications of infrared imaging guidance technology have been paid more and more attention. And with the increasing of the complexity of mission and environment, precision guided weapons make stricter demand for infrared imaging seeker. The demands for infrared imaging seeker include: high detection sensitivity, large dynamic range, having better target recognition capability, having better anti-jamming capability and better environment adaptability. To meet the strict demand of weapon system, several important issues should be considered in high-performance infrared imaging seeker design. The mission, targets, environment of infrared imaging guided missile must be regarded. The tradeoff among performance goal, design parameters, infrared technology constraints and missile constraints should be considered. The optimized application of IRFPA and ATR in complicated environment should be concerned. In this paper, some design considerations for high-performance infrared imaging seeker were discussed.

  9. Design and performance comparison of fuzzy logic based tracking controllers

    NASA Technical Reports Server (NTRS)

    Lea, Robert N.; Jani, Yashvant

    1992-01-01

    Several camera tracking controllers based on fuzzy logic principles have been designed and tested in software simulation in the software technology branch at the Johnson Space Center. The fuzzy logic based controllers utilize range measurement and pixel positions from the image as input parameters and provide pan and tilt gimble rate commands as output. Two designs of the rulebase and tuning process applied to the membership functions are discussed in light of optimizing performance. Seven test cases have been designed to test the performance of the controllers for proximity operations where approaches like v-bar, fly-around and station keeping are performed. The controllers are compared in terms of responsiveness, and ability to maintain the object in the field-of-view of the camera. Advantages of the fuzzy logic approach with respect to the conventional approach have been discussed in terms of simplicity and robustness.

  10. MSFC Skylab airlock module, volume 1. [systems design and performance

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The history and development of the Skylab Airlock Module and Payload Shroud is presented from initial concept through final design. A summary is given of the Airlock features and systems. System design and performance are presented for the Spent Stage Experiment Support Module, structure and mechanical systems, mass properties, thermal and environmental control systems, EVA/IVA suite system, electrical power system, sequential system, sequential system, and instrumentation system.

  11. Programmable Optoelectronic Multiprocessors: Design, Performance and CAD Development

    NASA Astrophysics Data System (ADS)

    Kiamilev, Fouad Eskender

    1992-01-01

    This thesis describes the development of Programmable Optoelectronic Multiprocessor (POEM) architectures and systems. POEM systems combine simple electronic processing elements with free-space optical interconnects to implement high-performance, massively-parallel computers. POEM architectures are fundamentally different from architectures used in conventional VLSI systems. Novel system partitioning and processing element design methods have been developed to ensure efficient implementation of POEM architectures with optoelectronic technology. The main contributions of this thesis are: architecture and software design for the POEM prototype built at UCSD; detailed technology design-tradeoff and comparison studies for POEM interconnection networks; and application of the VHSIC Hardware Description Language (VHDL) to the design, simulation, and synthesis of POEM computers. A general-purpose POEM SIMD parallel computer architecture has been designed for symbolic computing applications. A VHDL simulation of this architecture was written to test the POEM hardware running parallel programs prior to prototype fabrication. Detailed performance comparison of this architecture with all-optical computing, based on symbolic substitution, has also been carried out to show that POEMs offer higher computational efficiency. A detailed technological design of a packet-switched POEM multistage interconnection network system has been performed. This design uses optically interconnected stages of K x K electronic switching elements, where K is a variable parameter, called grain-size, that determines the ratio of optics to electronics in the system. A thorough cost and performance comparison between this design and existing VLSI implementations was undertaken to show that the POEM approach offers better scalability and higher performance. The grain-size was optimized, showing that switch sizes of 16 x 16 to 256 x 256 provide maximum performance/cost. The effects of varying

  12. Design and performance of a 250 Hz alexandrite laser

    SciTech Connect

    Sam, R.C.; Yeh, J.J.; Leslie, K.R.; Rapoport, W.R.

    1988-06-01

    The design, analysis, and performance of a 250 Hz alexandrite laser are described. Built as the wavelength selective laser for a molecular laser isotope separation program, the laser has to satisfy specifications on its tuning band, linewidth, output energy, temporal behavior, and repetition rate required by the process. The key design feature is the use of a tandem rod oscillator with concave curvature on rod ends for thermal lensing compensation. A model was developed to project the stability range and beam quality relative to repetition rate. The performance results of a delivered system are presented and future developments are discussed.

  13. RTOD- RADIAL TURBINE OFF-DESIGN PERFORMANCE ANALYSIS

    NASA Technical Reports Server (NTRS)

    Glassman, A. J.

    1994-01-01

    The RTOD program was developed to accurately predict radial turbine off-design performance. The radial turbine has been used extensively in automotive turbochargers and aircraft auxiliary power units. It is now being given serious consideration for primary powerplant applications. In applications where the turbine will operate over a wide range of power settings, accurate off-design performance prediction is essential for a successful design. RTOD predictions have already illustrated a potential improvement in off-design performance offered by rotor back-sweep for high-work-factor radial turbines. RTOD can be used to analyze other potential performance enhancing design features. RTOD predicts the performance of a radial turbine (with or without rotor blade sweep) as a function of pressure ratio, speed, and stator setting. The program models the flow with the following: 1) stator viscous and trailing edge losses; 2) a vaneless space loss between the stator and the rotor; and 3) rotor incidence, viscous, trailing-edge, clearance, and disk friction losses. The stator and rotor viscous losses each represent the combined effects of profile, endwall, and secondary flow losses. The stator inlet and exit and the rotor inlet flows are modeled by a mean-line analysis, but a sector analysis is used at the rotor exit. The leakage flow through the clearance gap in a pivoting stator is also considered. User input includes gas properties, turbine geometry, and the stator and rotor viscous losses at a reference performance point. RTOD output includes predicted turbine performance over a specified operating range and any user selected flow parameters. The RTOD program is written in FORTRAN IV for batch execution and has been implemented on an IBM 370 series computer with a central memory requirement of approximately 100K of 8 bit bytes. The RTOD program was developed in 1983.

  14. Spacecraft active thermal control subsystem design and operation considerations

    NASA Technical Reports Server (NTRS)

    Sadunas, J. A.; Lehtinen, A. M.; Nguyen, H. T.; Parish, R.

    1986-01-01

    Future spacecraft missions will be characterized by high electrical power requiring active thermal control subsystems for acquisition, transport, and rejection of waste heat. These systems will be designed to operate with minimum maintenance for up to 10 years, with widely varying externally-imposed environments, as well as the spacecraft waste heat rejection loads. This paper presents the design considerations and idealized performance analysis of a typical thermal control subsystem with emphasis on the temperature control aspects during off-design operation. The selected thermal management subsystem is a cooling loop for a 75-kWe fuel cell subsystem, consisting of a fuel cell heat exchanger, thermal storage, pumps, and radiator. Both pumped-liquid transport and two-phase (liquid/vapor) transport options are presented with examination of similarities and differences of the control requirements for these representative thermal control options.

  15. Injector Cavities Fabrication, Vertical Test Performance and Primary Cryomodule Design

    SciTech Connect

    Wang, Haipeng; Cheng, Guangfeng; Clemens, William; Davis, G; Macha, Kurt; Overton, Roland; Spell, D.

    2015-09-01

    After the electromagnetic design and the mechanical design of a β=0.6, 2-cell elliptical SRF cavity, the cavity has been fabricated. Then both 2-cell and 7-cell cavities have been bench tuned to the target values of frequency, coupling external Q and field flatness. After buffer chemistry polishing (BCP) and high pressure rinses (HPR), Vertical 2K cavity test results have been satisfied the specifications and ready for the string assembly. We will report the cavity performance including Lorenz Force Detuning (LFD) and Higher Order Modes (HOM) damping data. Its integration with cavity tuners to the cryomodule design will be reported.

  16. Design and performance verification of a passive propellant management system

    NASA Technical Reports Server (NTRS)

    Hess, D. A.; Regnier, W. W.

    1978-01-01

    This paper describes the design and verification testing of a reusable passive propellant management system. The system was designed to acquire propellant in low- or zero-g environments and also retain this propellant under high axially directed accelerations that may be experienced during launch and orbit-to-orbit transfer. The system design requirements were established to satisfy generally the requirements for a large number of potential NASA and military applications, such as orbit-to-orbit shuttles and satellite vehicles. The resulting concept was a multicompartmented tank with independent surface tension acquisition channels in each compartment. The tank was designed to provide a minimum expulsion efficiency of 98 percent when subjected to the simultaneous conditions of acceleration, vibration, and outflow. The system design has the unique capability to demonstrate low-g performance in a 1-g test environment, and the test program summarized was structured around this capability.

  17. Designing Liquid Rocket Engine Injectors for Performance, Stability, and Cost

    NASA Technical Reports Server (NTRS)

    Westra, Douglas G.; West, Jeffrey S.

    2014-01-01

    NASA is developing the Space Launch System (SLS) for crewed exploration missions beyond low Earth orbit. Marshall Space Flight Center (MSFC) is designing rocket engines for the SLS Advanced Booster (AB) concepts being developed to replace the Shuttle-derived solid rocket boosters. One AB concept uses large, Rocket-Propellant (RP)-fueled engines that pose significant design challenges. The injectors for these engines require high performance and stable operation while still meeting aggressive cost reduction goals for access to space. Historically, combustion stability problems have been a critical issue for such injector designs. Traditional, empirical injector design tools and methodologies, however, lack the ability to reliably predict complex injector dynamics that often lead to combustion stability. Reliance on these tools alone would likely result in an unaffordable test-fail-fix cycle for injector development. Recently at MSFC, a massively parallel computational fluid dynamics (CFD) program was successfully applied in the SLS AB injector design process. High-fidelity reacting flow simulations were conducted for both single-element and seven-element representations of the full-scale injector. Data from the CFD simulations was then used to significantly augment and improve the empirical design tools, resulting in a high-performance, stable injector design.

  18. Seismic design and evaluation criteria based on target performance goals

    SciTech Connect

    Murray, R.C.; Nelson, T.A.; Kennedy, R.P.; Short, S.A.

    1994-04-01

    The Department of Energy utilizes deterministic seismic design/evaluation criteria developed to achieve probabilistic performance goals. These seismic design and evaluation criteria are intended to apply equally to the design of new facilities and to the evaluation of existing facilities. In addition, the criteria are intended to cover design and evaluation of buildings, equipment, piping, and other structures. Four separate sets of seismic design/evaluation criteria have been presented each with a different performance goal. In all these criteria, earthquake loading is selected from seismic hazard curves on a probabilistic basis but seismic response evaluation methods and acceptable behavior limits are deterministic approaches with which design engineers are familiar. For analytical evaluations, conservatism has been introduced through the use of conservative inelastic demand-capacity ratios combined with ductile detailing requirements, through the use of minimum specified material strengths and conservative code capacity equations, and through the use of a seismic scale factor. For evaluation by testing or by experience data, conservatism has been introduced through the use of an increase scale factor which is applied to the prescribed design/evaluation input motion.

  19. An Approach for Performance Assessments of Extravehicular Activity Gloves

    NASA Technical Reports Server (NTRS)

    Aitchison, Lindsay; Benosn, Elizabeth

    2014-01-01

    The Space Suit Assembly (SSA) Development Team at NASA Johnson Space Center has invested heavily in the advancement of rear-entry planetary exploration suit design but largely deferred development of extravehicular activity (EVA) glove designs, and accepted the risk of using the current flight gloves, Phase VI, for unique mission scenarios outside the Space Shuttle and International Space Station (ISS) Program realm of experience. However, as design reference missions mature, the risks of using heritage hardware have highlighted the need for developing robust new glove technologies. To address the technology gap, the NASA Game-Changing Technology group provided start-up funding for the High Performance EVA Glove (HPEG) Project in the spring of 2012. The overarching goal of the HPEG Project is to develop a robust glove design that increases human performance during EVA and creates pathway for future implementation of emergent technologies, with specific aims of increasing pressurized mobility to 60% of barehanded capability, increasing the durability by 100%, and decreasing the potential of gloves to cause injury during use. The HPEG Project focused initial efforts on identifying potential new technologies and benchmarking the performance of current state of the art gloves to identify trends in design and fit leading to establish standards and metrics against which emerging technologies can be assessed at both the component and assembly levels. The first of the benchmarking tests evaluated the quantitative mobility performance and subjective fit of two sets of prototype EVA gloves developed ILC Dover and David Clark Company as compared to the Phase VI. Both companies were asked to design and fabricate gloves to the same set of NASA provided hand measurements (which corresponded to a single size of Phase Vi glove) and focus their efforts on improving mobility in the metacarpal phalangeal and carpometacarpal joints. Four test subjects representing the design-to hand

  20. High performance composites with active stiffness control.

    PubMed

    Tridech, Charnwit; Maples, Henry A; Robinson, Paul; Bismarck, Alexander

    2013-09-25

    High performance carbon fiber reinforced composites with controllable stiffness could revolutionize the use of composite materials in structural applications. Here we describe a structural material, which has a stiffness that can be actively controlled on demand. Such a material could have applications in morphing wings or deployable structures. A carbon fiber reinforced-epoxy composite is described that can undergo an 88% reduction in flexural stiffness at elevated temperatures and fully recover when cooled, with no discernible damage or loss in properties. Once the stiffness has been reduced, the required deformations can be achieved at much lower actuation forces. For this proof-of-concept study a thin polyacrylamide (PAAm) layer was electrocoated onto carbon fibers that were then embedded into an epoxy matrix via resin infusion. Heating the PAAm coating above its glass transition temperature caused it to soften and allowed the fibers to slide within the matrix. To produce the stiffness change the carbon fibers were used as resistance heating elements by passing a current through them. When the PAAm coating had softened, the ability of the interphase to transfer load to the fibers was significantly reduced, greatly lowering the flexural stiffness of the composite. By changing the moisture content in PAAm fiber coating, the temperature at which the PAAm softens and the composites undergo a reduction in stiffness can be tuned. PMID:23978266

  1. Structural Design Strategies for Improved Small Overlap Crashworthiness Performance.

    PubMed

    Mueller, Becky C; Brethwaite, Andrew S; Zuby, David S; Nolan, Joseph M

    2014-11-01

    In 2012, the Insurance Institute for Highway Safety (IIHS) began a 64 km/h small overlap frontal crash test consumer information test program. Thirteen automakers already have redesigned models to improve test performance. One or more distinct strategies are evident in these redesigns: reinforcement of the occupant compartment, use of energy-absorbing fender structures, and the addition of engagement structures to induce vehicle lateral translation. Each strategy influences vehicle kinematics, posing additional challenges for the restraint systems. The objective of this two-part study was to examine how vehicles were modified to improve small overlap test performance and then to examine how these modifications affect dummy response and restraint system performance. Among eight models tested before and after design changes, occupant compartment intrusion reductions ranged from 6 cm to 45 cm, with the highest reductions observed in models with the largest number of modifications. All redesigns included additional occupant compartment reinforcement, one-third added structures to engage the barrier, and two modified a shotgun load path. Designs with engagement structures produced greater glance-off from the barrier and exhibited lower delta Vs but experienced more lateral outboard motion of the dummy. Designs with heavy reinforcement of the occupant compartment had higher vehicle accelerations and delta V. In three cases, these apparent trade-offs were not well addressed by concurrent changes in restraint systems and resulted in increased injury risk compared with the original tests. Among the 36 models tested after design changes, the extent of design changes correlated to structural performance. Half of the vehicles with the lowest intrusion levels incorporated aspects of all three design strategies. Vehicle kinematics and dummy and restraint system characteristics were similar to those observed in the before/after pairs. Different combinations of structural

  2. Structural Design Strategies for Improved Small Overlap Crashworthiness Performance.

    PubMed

    Mueller, Becky C; Brethwaite, Andrew S; Zuby, David S; Nolan, Joseph M

    2014-11-01

    In 2012, the Insurance Institute for Highway Safety (IIHS) began a 64 km/h small overlap frontal crash test consumer information test program. Thirteen automakers already have redesigned models to improve test performance. One or more distinct strategies are evident in these redesigns: reinforcement of the occupant compartment, use of energy-absorbing fender structures, and the addition of engagement structures to induce vehicle lateral translation. Each strategy influences vehicle kinematics, posing additional challenges for the restraint systems. The objective of this two-part study was to examine how vehicles were modified to improve small overlap test performance and then to examine how these modifications affect dummy response and restraint system performance. Among eight models tested before and after design changes, occupant compartment intrusion reductions ranged from 6 cm to 45 cm, with the highest reductions observed in models with the largest number of modifications. All redesigns included additional occupant compartment reinforcement, one-third added structures to engage the barrier, and two modified a shotgun load path. Designs with engagement structures produced greater glance-off from the barrier and exhibited lower delta Vs but experienced more lateral outboard motion of the dummy. Designs with heavy reinforcement of the occupant compartment had higher vehicle accelerations and delta V. In three cases, these apparent trade-offs were not well addressed by concurrent changes in restraint systems and resulted in increased injury risk compared with the original tests. Among the 36 models tested after design changes, the extent of design changes correlated to structural performance. Half of the vehicles with the lowest intrusion levels incorporated aspects of all three design strategies. Vehicle kinematics and dummy and restraint system characteristics were similar to those observed in the before/after pairs. Different combinations of structural

  3. A Guide to Microsoft Active Directory (AD) Design

    SciTech Connect

    Dias, J

    2002-04-29

    The goal of this paper is to facilitate the design process for those DOE sites that are currently engaged in designing their Active Directory (AD) network. It is a roadmap to enable analysis of the complicated design tradeoffs associated with Active Directory Design. By providing discussion of Active Directory design elements which are permanent and costly to change once deployed, the hope is to minimize the risks of sponsoring failed designs, or joining existing infrastructures not suitable to programmatic needs. Specifically, most Active Directory structures will fall under one of three common designs: Single Domain, Single Forest with Multiple Domains, or Multiple Forests. Each has benefits and concerns, depending on programmatic and organizational structures. The comparison of these three approaches will facilitate almost any Active Directory design effort. Finally, this paper describes some best practices to consider when designing Active Directory based on three years of research and experience.

  4. Integrated design environment for human performance and human reliability analysis

    SciTech Connect

    Nelson, W.R.

    1997-05-01

    Work over the last few years at the Idaho National Engineering and Environmental Laboratory (INEEL) has included a major focus on applying human performance and human reliability knowledge and methods as an integral element of system design and development. This work has been pursued in programs in a wide variety of technical domains, beginning with nuclear power plant operations. Since the mid-1980`s the laboratory has transferred the methods and tools developed in the nuclear domain to military weapons systems and aircraft, offshore oil and shipping operations, and commercial aviation operations and aircraft design. Through these diverse applications the laboratory has developed an integrated approach and framework for application of human performance analysis, human reliability analysis (HRA), operational data analysis, and simulation studies of human performance to the design and development of complex systems. This approach was recently tested in the NASA Advanced Concepts Program {open_quotes}Structured Human Error Analysis for Aircraft Design.{close_quotes} This program resulted in the prototype software tool THEA (Tool for Human Error Analysis) for incorporating human error analysis in the design of commercial aircraft, focusing on airplane maintenance tasks. Current effort is directed toward applying this framework to the development of advanced Air Traffic Management (ATM) systems as part of NASA`s Advanced Air Transportation Technologies (AATT) program. This paper summarizes the approach, describes recent and current applications in commercial aviation, and provides perspectives on how the approach could be utilized in the nuclear power industry.

  5. The ergonomics of learning: educational design and learning performance.

    PubMed

    Smith, T J

    2007-10-01

    The application of ergonomics/human factors (E/HF) principles and practices, and the implementation of ergonomics programmes, have achieved proven success in improving performance, productivity, competitiveness, and safety and health in most occupational sectors. However, the benefits that the application of E/HF science might bring to promoting student learning have yet to be widely recognized. This paper deals with the fundamental purpose of education - student learning - and with the question of how the ergonomic design of the learning environment influences learning performance. The underlying premise, embodied in the quote below, is that student learning performance to a substantial degree is context specific - influenced and specialized in relation to specific design factors in the learning environment. The basic scientific question confronting learning ergonomics is which design characteristics in the learning environment have the greatest influence on variability in learning performance. Practically, the basic challenge is to apply this scientific understanding to ergonomic interventions directed at design improvements of learning environments to benefit learning. This paper expands upon these themes by addressing the origins and scope of learning ergonomics, differing perspectives on the nature of learning, evidence for context specificity in learning and conclusions and research implications regarding an ergonomics perspective on learning.

  6. Optimizing the design of very high power, high performance converters

    SciTech Connect

    Edwards, R J; Tiagha, E A; Ganetis, G; Nawrocky, R J

    1980-01-01

    This paper describes how various technologies are used to achieve the desired performance in a high current magnet power converter system. It is hoped that the discussions of the design approaches taken will be applicable to other power supply systems where stringent requirements in stability, accuracy and reliability must be met.

  7. EarthCARE/CPR design results and PFM performance

    NASA Astrophysics Data System (ADS)

    Aida, Yoshihisa; Tomita, Eichi; Nakatsuka, Hirotaka; Seki, Yoshihiro; Okada, Kazuyuki; Kadosaki, Gaku; Iide, Yoshiya; Horie, Hiroaki; Sato, Kenji; Ohno, Yuichi; Takahashi, Nobuhiro

    2013-10-01

    ESA and JAXA plan to launch a satellite called EarthCARE (Earth Clouds, Aerosols and Radiation Explorer). The Cloud Profiling Radar (CPR), which will be the first millimeter-wave Doppler radar in space, is installed on this satellite as one of main sensors to observe clouds. This paper describes the design results and PFM performance of EarthCARE CPR.

  8. Performance-Centered Design for Developing Countries: Emphasizing Context.

    ERIC Educational Resources Information Center

    Arias, Sonia

    2002-01-01

    Discusses performance-centered design (PCD) for developing countries and demonstrates how the process of internationalization and localization needs to go beyond the traditional functionality checklists of culture and language. Describes how the unique nature of developing country economic, human capacity, and infrastructure contexts has to be…

  9. Guide to School Design: Healthy + High Performance Schools

    ERIC Educational Resources Information Center

    Healthy Schools Network, Inc., 2007

    2007-01-01

    A "healthy and high performance school" uses a holistic design process to promote the health and comfort of children and school employees, as well as conserve resources. Children may spend over eight hours a day at school with little, if any, legal protection from environmental hazards. Schools are generally not well-maintained; asthma is a…

  10. OFF-DESIGN PERFORMANCE OF RADIAL INFLOW TURBINES

    NASA Technical Reports Server (NTRS)

    Wasserbauer, C. A.

    1994-01-01

    This program calculates off design performance of radial inflow turbines. The program uses a one dimensional solution of flow conditions through the turbine along the main streamline. The loss model accounts for stator, rotor, incidence, and exit losses. Program features include consideration of stator and rotor trailing edge blockage and computation of performance to limiting load. Stator loss (loss in kinetic energy across the stator) is proportional to the average kinetic energy in the blade row and is represented in the program by an equation which includes a stator loss coefficient determined from design point performance and then assumed to be constant for the off design calculations. Minimum incidence loss does not occur at zero incidence angle with respect to the rotor blade, but at some optimum flow angle. At high pressure ratios the level of rotor inlet velocity seemed to have an excessive influence on the loss. Using the component of velocity in the direction of the optimum flow angle gave better correlations with experimental results. Overall turbine geometry and design point values of efficiency, pressure ratio, and mass flow are needed as input information. The output includes performance and velocity diagram parameters for any number of given speeds over a range of turbine pressure ratio. The program has been implemented on the IBM 7094 and operates in batch mode.

  11. PHARAO laser source flight model: Design and performances

    SciTech Connect

    Lévèque, T. Faure, B.; Esnault, F. X.; Delaroche, C.; Massonnet, D.; Grosjean, O.; Buffe, F.; Torresi, P.; Bomer, T.; Pichon, A.; Béraud, P.; Lelay, J. P.; Thomin, S.; Laurent, Ph.

    2015-03-15

    In this paper, we describe the design and the main performances of the PHARAO laser source flight model. PHARAO is a laser cooled cesium clock specially designed for operation in space and the laser source is one of the main sub-systems. The flight model presented in this work is the first remote-controlled laser system designed for spaceborne cold atom manipulation. The main challenges arise from mechanical compatibility with space constraints, which impose a high level of compactness, a low electric power consumption, a wide range of operating temperature, and a vacuum environment. We describe the main functions of the laser source and give an overview of the main technologies developed for this instrument. We present some results of the qualification process. The characteristics of the laser source flight model, and their impact on the clock performances, have been verified in operational conditions.

  12. The CDF Run IIb Silicon Detector: Design, preproduction, and performance

    NASA Astrophysics Data System (ADS)

    Akimoto, T.; Aoki, M.; Azzi, P.; Bacchetta, N.; Behari, S.; Benjamin, D.; Bisello, D.; Bolla, G.; Bortoletto, D.; Burghard, A.; Busetto, G.; Cabrera, S.; Canepa, A.; Cardoso, G.; Chertok, M.; Ciobanu, C. I.; Derylo, G.; Fang, I.; Feng, E. J.; Fernandez, J. P.; Flaugher, B.; Freeman, J.; Galtieri, L.; Galyardt, J.; Garcia-Sciveres, M.; Giurgiu, G.; Gorelov, I.; Haber, C.; Hale, D.; Hara, K.; Harr, R.; Hill, C.; Hoeferkamp, M.; Hoff, J.; Holbrook, B.; Hong, S. C.; Hrycyk, M.; Hsiung, T. H.; Incandela, J.; Jeon, E. J.; Joo, K. K.; Junk, T.; Kahkola, H.; Karjalainen, S.; Kim, S.; Kobayashi, K.; Kong, D. J.; Krieger, B.; Kruse, M.; Kuznetsova, N.; Kyre, S.; Lander, R.; Landry, T.; Lauhakangas, R.; Lee, J.; Lu, R.-S.; Lujan, P.; Lukens, P.; Mandelli, E.; Manea, C.; Maksimovic, P.; Merkel, P.; Min, S. N.; Moccia, S.; Nakano, I.; Naoumov, D.; Nelson, T.; Nord, B.; Novak, J.; Okusawa, T.; Orava, R.; Orlov, Y.; Osterberg, K.; Pantano, D.; Pavlicek, V.; Pellett, D.; Pursley, J.; Riipinen, P.; Schuyler, B.; Seidel, S.; Shenai, A.; Soha, A.; Stuart, D.; Tanaka, R.; Tavi, M.; Von der Lippe, H.; Walder, J.-P.; Wang, Z.; Watje, P.; Weber, Marc; Wester, W.; Yamamoto, K.; Yang, Y. C.; Yao, W.; Yao, W.; Yarema, R.; Yun, J. C.; Zetti, F.; Zimmerman, T.; Zimmermann, S.; Zucchelli, S.

    2006-01-01

    A new silicon microstrip detector was designed by the CDF collaboration for the proposed high-luminosity operation of the Tevatron pp¯ collider (Run IIb). The detector is radiation-tolerant and will still be functional after exposure to particle fluences of 1014 1-MeV equivalent neutrons/cm2 and radiation doses of 20 MRad. The detector will maintain or exceed the performance of the current CDF silicon detector throughout Run IIb. It is based on an innovative silicon "supermodule" design. Critical detector components like the custom radiation-hard SVX4 readout chip, the beryllia hybrids and mini-port (repeater) cards, and the silicon sensors fulfill their specifications and were produced with high yields. The design goals and solutions of the CDF Run IIb silicon detector are described, and the performance of preproduction modules is presented in detail. Results relevant for the development of future silicon systems are emphasized.

  13. Designing high-performance layered thermoelectric materials through orbital engineering

    PubMed Central

    Zhang, Jiawei; Song, Lirong; Madsen, Georg K. H.; Fischer, Karl F. F.; Zhang, Wenqing; Shi, Xun; Iversen, Bo B.

    2016-01-01

    Thermoelectric technology, which possesses potential application in recycling industrial waste heat as energy, calls for novel high-performance materials. The systematic exploration of novel thermoelectric materials with excellent electronic transport properties is severely hindered by limited insight into the underlying bonding orbitals of atomic structures. Here we propose a simple yet successful strategy to discover and design high-performance layered thermoelectric materials through minimizing the crystal field splitting energy of orbitals to realize high orbital degeneracy. The approach naturally leads to design maps for optimizing the thermoelectric power factor through forming solid solutions and biaxial strain. Using this approach, we predict a series of potential thermoelectric candidates from layered CaAl2Si2-type Zintl compounds. Several of them contain nontoxic, low-cost and earth-abundant elements. Moreover, the approach can be extended to several other non-cubic materials, thereby substantially accelerating the screening and design of new thermoelectric materials. PMID:26948043

  14. Designing high-performance layered thermoelectric materials through orbital engineering.

    PubMed

    Zhang, Jiawei; Song, Lirong; Madsen, Georg K H; Fischer, Karl F F; Zhang, Wenqing; Shi, Xun; Iversen, Bo B

    2016-01-01

    Thermoelectric technology, which possesses potential application in recycling industrial waste heat as energy, calls for novel high-performance materials. The systematic exploration of novel thermoelectric materials with excellent electronic transport properties is severely hindered by limited insight into the underlying bonding orbitals of atomic structures. Here we propose a simple yet successful strategy to discover and design high-performance layered thermoelectric materials through minimizing the crystal field splitting energy of orbitals to realize high orbital degeneracy. The approach naturally leads to design maps for optimizing the thermoelectric power factor through forming solid solutions and biaxial strain. Using this approach, we predict a series of potential thermoelectric candidates from layered CaAl2Si2-type Zintl compounds. Several of them contain nontoxic, low-cost and earth-abundant elements. Moreover, the approach can be extended to several other non-cubic materials, thereby substantially accelerating the screening and design of new thermoelectric materials. PMID:26948043

  15. Designing high-performance layered thermoelectric materials through orbital engineering

    NASA Astrophysics Data System (ADS)

    Zhang, Jiawei; Song, Lirong; Madsen, Georg K. H.; Fischer, Karl F. F.; Zhang, Wenqing; Shi, Xun; Iversen, Bo B.

    2016-03-01

    Thermoelectric technology, which possesses potential application in recycling industrial waste heat as energy, calls for novel high-performance materials. The systematic exploration of novel thermoelectric materials with excellent electronic transport properties is severely hindered by limited insight into the underlying bonding orbitals of atomic structures. Here we propose a simple yet successful strategy to discover and design high-performance layered thermoelectric materials through minimizing the crystal field splitting energy of orbitals to realize high orbital degeneracy. The approach naturally leads to design maps for optimizing the thermoelectric power factor through forming solid solutions and biaxial strain. Using this approach, we predict a series of potential thermoelectric candidates from layered CaAl2Si2-type Zintl compounds. Several of them contain nontoxic, low-cost and earth-abundant elements. Moreover, the approach can be extended to several other non-cubic materials, thereby substantially accelerating the screening and design of new thermoelectric materials.

  16. Designing high-performance layered thermoelectric materials through orbital engineering.

    PubMed

    Zhang, Jiawei; Song, Lirong; Madsen, Georg K H; Fischer, Karl F F; Zhang, Wenqing; Shi, Xun; Iversen, Bo B

    2016-03-07

    Thermoelectric technology, which possesses potential application in recycling industrial waste heat as energy, calls for novel high-performance materials. The systematic exploration of novel thermoelectric materials with excellent electronic transport properties is severely hindered by limited insight into the underlying bonding orbitals of atomic structures. Here we propose a simple yet successful strategy to discover and design high-performance layered thermoelectric materials through minimizing the crystal field splitting energy of orbitals to realize high orbital degeneracy. The approach naturally leads to design maps for optimizing the thermoelectric power factor through forming solid solutions and biaxial strain. Using this approach, we predict a series of potential thermoelectric candidates from layered CaAl2Si2-type Zintl compounds. Several of them contain nontoxic, low-cost and earth-abundant elements. Moreover, the approach can be extended to several other non-cubic materials, thereby substantially accelerating the screening and design of new thermoelectric materials.

  17. Design and performance of airborne radomes - A review

    NASA Astrophysics Data System (ADS)

    Crone, G. A. E.; Rudge, A. W.; Taylor, G. N.

    1981-12-01

    Radomes for airborne amplification can be classified as either (1) large aircraft radomes of the nose-cone or under-fuselage type, (2) small aircraft radomes flush-mounted to the airframe, or (3) missile radomes. The geometry of the radome often leads to severe degradation of the electrical performance of any enclosed antenna. The requirement for a good aerodynamic shape is shown to influence the electromagnetic design of the radome, and the choice of dielectric materials is limited by the needs for structural strength, low weight, thermal stability, and rain erosion resistance. The radome performance may also be compromised by the scattering of electromagnetic waves from metallic pilot tubes and lightning protection strips outside the radome, as well as dielectric pressure tubes within it. The electromagnetic design of the three types of radomes are reviewed, sources of degradation of the enclosed antenna radiation pattern are examined, and the design requirements of the radomes, with respect to their operational environment, are discussed.

  18. 40 CFR 63.5850 - How do I conduct performance tests, performance evaluations, and design evaluations?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Pollutants: Reinforced Plastic Composites Production Testing and Initial Compliance Requirements § 63.5850... performance test, performance evaluation, and design evaluation in 40 CFR part 63, subpart SS, that applies to... requirements in § 63.7(e)(1) and under the specific conditions that 40 CFR part 63, subpart SS, specifies....

  19. 40 CFR 63.5850 - How do I conduct performance tests, performance evaluations, and design evaluations?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Pollutants: Reinforced Plastic Composites Production Testing and Initial Compliance Requirements § 63.5850... performance test, performance evaluation, and design evaluation in 40 CFR part 63, subpart SS, that applies to... requirements in § 63.7(e)(1) and under the specific conditions that 40 CFR part 63, subpart SS, specifies....

  20. 40 CFR 63.5850 - How do I conduct performance tests, performance evaluations, and design evaluations?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... performance test, performance evaluation, and design evaluation in 40 CFR part 63, subpart SS, that applies to... requirements in § 63.7(e)(1) and under the specific conditions that 40 CFR part 63, subpart SS, specifies. (c... and under the specific conditions that 40 CFR part 63, subpart SS, specifies. (d) You may not...

  1. Design, fabrication & performance analysis of an unmanned aerial vehicle

    NASA Astrophysics Data System (ADS)

    Khan, M. I.; Salam, M. A.; Afsar, M. R.; Huda, M. N.; Mahmud, T.

    2016-07-01

    An Unmanned Aerial Vehicle was designed, analyzed and fabricated to meet design requirements and perform the entire mission for an international aircraft design competition. The goal was to have a balanced design possessing, good demonstrated flight handling qualities, practical and affordable manufacturing requirements while providing a high vehicle performance. The UAV had to complete total three missions named ferry flight (1st mission), maximum load mission (2nd mission) and emergency medical mission (3rd mission). The requirement of ferry flight mission was to fly as many as laps as possible within 4 minutes. The maximum load mission consists of flying 3 laps while carrying two wooden blocks which simulate cargo. The requirement of emergency medical mission was complete 3 laps as soon as possible while carrying two attendances and two patients. A careful analysis revealed lowest rated aircraft cost (RAC) as the primary design objective. So, the challenge was to build an aircraft with minimum RAC that can fly fast, fly with maximum payload, and fly fast with all the possible configurations. The aircraft design was reached by first generating numerous design concepts capable of completing the mission requirements. In conceptual design phase, Figure of Merit (FOM) analysis was carried out to select initial aircraft configuration, propulsion, empennage and landing gear. After completion of the conceptual design, preliminary design was carried out. The preliminary design iterations had a low wing loading, high lift coefficient, and a high thrust to weight ratio. To make the aircraft capable of Rough Field Taxi; springs were added in the landing gears for absorbing shock. An airfoil shaped fuselage was designed to allowed sufficient space for payload and generate less drag to make the aircraft fly fast. The final design was a high wing monoplane with conventional tail, single tractor propulsion system and a tail dragger landing gear. Payload was stored in

  2. ESBWR - Robust design for natural circulation and stability performance effectiveness

    SciTech Connect

    Alamgir, M. D.; Marquino, W.; Yang, J.; Saha, P.; Fennern, L.; Colby, M.

    2012-07-01

    ESBWR is a 4500 MWt Generation III+ natural circulation reactor with an array of robust design features and passive safety systems to deliver highly effective plant performance during normal operation and to keep the reactor safe during postulated transients and accidents. With the submittal of the latest revision of the Design Control Document (DCD) to US Nuclear Regulatory Commission, ESBWR is nearing the completion of the US design certification process. This paper focuses on the natural circulation-driven plant performance aspects during normal operation, and stability evaluation of the robust ESBWR design. The TRACG computer code is used for the analysis of ESBWR plant performance, safety analysis, and stability margins. The paper describes the evaluation of ESBWR stability performance during normal power operation including operation in the Core Power-Feed Water Temperature Operating Domain. For ESBWR the normal power operation condition has the highest power/flow ratio and is limiting from the perspective of stability. The paper includes results from detailed evaluation of the most limiting decay ratio for out-of-phase regional oscillations calculated by perturbing the core inlet flow rate in this out-of-phase mode about the line of symmetry for the azimuthal harmonic mode. The paper also summarizes the ESBWR regional mode stability evaluations during a limiting transient (Loss of Feedwater Heating), and during ATWS (Anticipated Transient without Scram). Nominal decay ratios of limiting Channel oscillation, Core wide oscillation and Regional oscillation are within the maximum acceptance criterion of 0.8, at 95% content and 95% confidence. These stability evaluation results indicate decay ratio is within design limits. The paper also describes the evaluation of ESBWR stability performance during plant startup, and summarizes the defense-in-depth stability solution for ESBWR. (authors)

  3. Optical design, performance, and tolerancing of an Offner imaging spectrograph

    NASA Astrophysics Data System (ADS)

    Ku, Hana; Kim, Seo Hyun; Kong, Hong Jin; Lee, Jun Ho

    2012-10-01

    We introduce a design of an Offner imaging spectrograph with its performance and tolerancing results. It is a traditional Offner spectrograph employing two concave mirrors and one convex reflective grating for dispersing light in the SWIR band (900~1700 nm). The optical system uses 25um-pitch pixels for the detector and the goal spectral sampling is 3.2nm. Its performance is analyzed in terms of MTFs, spot diagrams, and distortions - keystone and smile. This design focuses on the yaw(beta-tilt) sensitivity of the tertiary mirror as the compensator hence is expected to act as a performance-improving breakthrough for the entire system as the inverse sensitivity confirms it is the most sensitive component. The procedure of the inverse sensitivity evaluation is explained, and then budgeting the tolerances for each element for the practical production is described.

  4. The First Structure–Activity Relationship Studies for Designer Receptors Exclusively Activated by Designer Drugs

    PubMed Central

    2016-01-01

    Over the past decade, two independent technologies have emerged and been widely adopted by the neuroscience community for remotely controlling neuronal activity: optogenetics which utilize engineered channelrhodopsin and other opsins, and chemogenetics which utilize engineered G protein-coupled receptors (Designer Receptors Exclusively Activated by Designer Drugs (DREADDs)) and other orthologous ligand–receptor pairs. Using directed molecular evolution, two types of DREADDs derived from human muscarinic acetylcholine receptors have been developed: hM3Dq which activates neuronal firing, and hM4Di which inhibits neuronal firing. Importantly, these DREADDs were not activated by the native ligand acetylcholine (ACh), but selectively activated by clozapine N-oxide (CNO), a pharmacologically inert ligand. CNO has been used extensively in rodent models to activate DREADDs, and although CNO is not subject to significant metabolic transformation in mice, a small fraction of CNO is apparently metabolized to clozapine in humans and guinea pigs, lessening the translational potential of DREADDs. To effectively translate the DREADD technology, the next generation of DREADD agonists are needed and a thorough understanding of structure–activity relationships (SARs) of DREADDs is required for developing such ligands. We therefore conducted the first SAR studies of hM3Dq. We explored multiple regions of the scaffold represented by CNO, identified interesting SAR trends, and discovered several compounds that are very potent hM3Dq agonists but do not activate the native human M3 receptor (hM3). We also discovered that the approved drug perlapine is a novel hM3Dq agonist with >10 000-fold selectivity for hM3Dq over hM3. PMID:25587888

  5. Extended performance solar electric propulsion thrust system design

    NASA Technical Reports Server (NTRS)

    Cake, J. E.; Hawthorne, E. I.; Poeschel, R. L.

    1978-01-01

    A thrust system design has been established for an extended performance technology, 6.4 kW, 4800 sec specific impulse ion thruster. The configuration is comprised of ten thrusters configured with a power management and control subsystem in a modular thrust system design. The system design approach is an adaptation of that previously established for the baseline technology 2.7 kW, 3000 sec specific impulse ion thruster. The power management and control subsystem design includes a combination of individual electronics for each thruster and a set of electronics with redundancy that are common to all thrusters. The thermal dissipation from all electronics is removed with a common heat pipe/radiator assembly.

  6. Design of mechanical components for long-term performance

    NASA Technical Reports Server (NTRS)

    Salvinski, R. J.

    1974-01-01

    Review of the results of a NASA program designed to study advanced techniques for determining the long-term performance of rocket engine components. Aging and operational degradation mechanisms of metal valve seats are identified. Characterization of metal valve seat surfaces by optical signature analysis is described. The results of the development of a long-life 'zero leakage' metal valve seal designed to avoid failure by contamination, stress/strain, fatigue, and the deterioration of the surface by wear is reported. An analysis of a specific seat design showed that material strain prevention along all axes would prevent these failures. The design provided for refurbishment of the sealing surfaces during each valve cycle, thereby preventing cumulative surface damage.

  7. Design of a Performance-Adaptive PID Control System Based on Modeling Performance Assessment

    NASA Astrophysics Data System (ADS)

    Yamamoto, Toru

    In industrial processes represented by petroleum and refinery processes, it is necessary to establish the performance-driven control strategy in order to improve the productivity, which the control performance is firstly evaluated, and the controller is reconstructed. This paper describes a design scheme of performance-adaptive PID controllers which are based on the above control mechanism. According to the proposed control scheme, the system identification works corresponding to the result of modeling performance assessment, and PID parameters are computed using the newly estimated system parameters. In calculating the PID parameters, the desired control performance is considered. The behaviour of the proposed control scheme is numerically examined in some simulation examples.

  8. GENENG: A program for calculating design and off-design performance for turbojet and turbofan engines

    NASA Technical Reports Server (NTRS)

    Koenig, R. W.; Fishbach, L. H.

    1972-01-01

    A computer program entitled GENENG employs component performance maps to perform analytical, steady state, engine cycle calculations. Through a scaling procedure, each of the component maps can be used to represent a family of maps (different design values of pressure ratios, efficiency, weight flow, etc.) Either convergent or convergent-divergent nozzles may be used. Included is a complete FORTRAN 4 listing of the program. Sample results and input explanations are shown for one-spool and two-spool turbojets and two-spool separate- and mixed-flow turbofans operating at design and off-design conditions.

  9. Design of an active magnetic regenerator test apparatus

    NASA Astrophysics Data System (ADS)

    Rowe, A. M.; Barclay, J. A.

    2002-05-01

    The Active Magnetic Regenerator (AMR) has been shown to be a refrigeration technology with high efficiencies. Complex thermodynamic interactions in the regenerator, a shortage of suitable magnetic refrigerants, and difficulty in acquiring accurate experimental data have combined to hamper the development of AMR refrigerators. An apparatus to dynamically characterize the behavior of AMR beds is a valuable tool in furthering the development of the technology. This paper describes the design and construction of an AMR test apparatus. For initial tests, the apparatus has been used to examine the performance of Gd AMR beds operating in 2 T fields.

  10. Structural design and performance of a rear support walking frame.

    PubMed

    Woollam, P J; Miller, K; McLeod, N; Batty, D; Stallard, J

    2002-01-01

    Rear support walking frames provide predetermined vertical support for patients with dysfunctional lower limbs that have limited active control; the support is provided through a spring-loaded boom hinged on an upright stanchion mounted at the rear of a wheeled frame within which the patient ambulates. The application of these frames for total-body-involved cerebral palsy patients, in combination with a walking orthosis, has highlighted a number of practical problems that need to be addressed for the system to become fully viable. A composite material prototype walking frame has been developed that permits the patient to be transferred by a single carer without the need to use inappropriate manual handling techniques. The frame has improved structural properties, with stiffness in the sagittal and coronal planes increasing by between 50 and 100 per cent. Evaluation with patients showed that the greater structural stiffness permitted the objective of improved continuity of walking to be achieved. The strength of the frame is such that it can accommodate patients of up to 80 kg, more than twice that possible in the earlier system. Since the structural yield point is approximately twice the maximum working load, the device should not be prone to unacceptable fatigue characteristics. Despite the use of carbon composite materials (which have brittle failure characteristics), the mode of failure is of progressive collapse and is therefore inherently safe. The successful outcome of prototype testing has justified production development. Work is now proceeding on a design that incorporates further improvements in structural performance and ease of manufacture. PMID:12137287

  11. Experimental Vertical Stability Studies for ITER Performance and Design Guidance

    SciTech Connect

    Humphreys, D A; Casper, T A; Eidietis, N; Ferrera, M; Gates, D A; Hutchinson, I H; Jackson, G L; Kolemen, E; Leuer, J A; Lister, J; LoDestro, L L; Meyer, W H; Pearlstein, L D; Sartori, F; Walker, M L; Welander, A S; Wolfe, S M

    2008-10-13

    Operating experimental devices have provided key inputs to the design process for ITER axisymmetric control. In particular, experiments have quantified controllability and robustness requirements in the presence of realistic noise and disturbance environments, which are difficult or impossible to characterize with modeling and simulation alone. This kind of information is particularly critical for ITER vertical control, which poses some of the highest demands on poloidal field system performance, since the consequences of loss of vertical control can be very severe. The present work describes results of multi-machine studies performed under a joint ITPA experiment on fundamental vertical control performance and controllability limits. We present experimental results from Alcator C-Mod, DIII-D, NSTX, TCV, and JET, along with analysis of these data to provide vertical control performance guidance to ITER. Useful metrics to quantify this control performance include the stability margin and maximum controllable vertical displacement. Theoretical analysis of the maximum controllable vertical displacement suggests effective approaches to improving performance in terms of this metric, with implications for ITER design modifications. Typical levels of noise in the vertical position measurement which can challenge the vertical control loop are assessed and analyzed.

  12. Design and Performance of a Wideband Radio Telescope

    NASA Technical Reports Server (NTRS)

    Weinreb, Sander; Imbriale, William A.; Jones, Glenn; Mani, Handi

    2012-01-01

    The Goldstone Apple Valley Radio Telescope (GAVRT) is an outreach project, a partnership involving NASA's Jet Propulsion Laboratory (JPL), the Lewis Center for Educational Research (LCER), and the Apple Valley Unified School District near the NASA Goldstone deep space communication complex. This educational program currently uses a 34-meter antenna, DSS12, at Goldstone for classroom radio astronomy observations via the Internet. The current program utilizes DSS12 in two narrow frequency bands around S-band (2.3 GHz) and X-band (8.45 GHz), and is used by a training program involving a large number of secondary school teachers and their classrooms. To expand the program, a joint JPL/LCER project was started in mid-2006 to retrofit an additional existing 34-meter beam-waveguide antenna, DSS28, with wideband feeds and receivers to cover the 0.5-to- 14-GHz frequency bands. The DSS28 antenna has a 34-meter diameter main reflector, a 2.54-meter subreflector, and a set of beam waveguide mirrors surrounded by a 2.43-meter tube. The antenna was designed for high power and a narrow frequency band around 7.2 GHz. The performance at the low end of the frequency band desired for the educational program would be extremely poor if the beam waveguide system was used as part of the feed system. Consequently, the 34-meter antenna was retrofitted with a tertiary offset mirror placed at the vertex of the main reflector. The tertiary mirror can be rotated to use two wideband feeds that cover the 0.5-to-14-GHz band. The earlier designs for both GAVRT and the DSN only used narrow band feeds and consequently, only covered a small part of the S- and X-band frequencies. By using both a wideband feed and wideband amplifiers, the entire band from 0.5 to 14 GHz is covered, expanding significantly the science activities that can be studied using this system.

  13. Resistive wall mode active control physics design for KSTAR

    NASA Astrophysics Data System (ADS)

    Park, Y. S.; Sabbagh, S. A.; Bak, J. G.; Bialek, J. M.; Berkery, J. W.; Lee, S. G.; Oh, Y. K.

    2014-01-01

    As KSTAR H-mode operation approaches the region where the resistive wall mode (RWM) can be unstable, an important issue for future long pulse, high beta plasma operation is to evaluate RWM active feedback control performance using a planned active/passive RWM stabilization system on the device. In particular, an optimal design of feedback sensors allows mode stabilization up to the highest achievable βN close to the ideal with-wall limit, βNwall, with reduced control power requirements. The computed ideal n = 1 mode structure from the DCON code has been input to the VALEN-3D code to calculate the projected performance of an active RWM control system in the KSTAR three-dimensional conducting structure device geometry. Control performance with the midplane locked mode detection sensors, off-midplane saddle loops, and magnetic pickup coils is examined. The midplane sensors measuring the radial component of the mode perturbation is found to be strongly affected by the wall eddy current. The off-axis saddle loops with proper compensation of the prompt applied field are computed to provide stabilization at βN up to 86% of βNwall but the low RWM amplitude computed in the off-axis regions near the sensors can produce a low signal-to-noise ratio. The required control power and bandwidth are also estimated with varied noise levels in the feedback sensors. Further improvements have been explored by examining a new RWM sensor design motivated by the off-midplane poloidal magnetic field sensors in NSTX. The new sensors mounted off of the copper passive stabilizer plates near the device midplane show a clear advantage in control performance corresponding to achieving 99% of βNwall without the need of compensation of the prompt field. The result shows a significant improvement of RWM feedback stabilization using the new sensor set which motivates a future feedback sensor upgrade.

  14. Designing a database for performance assessment: Lessons learned from WIPP

    SciTech Connect

    Martell, M.A.; Schenker, A.

    1997-12-01

    The Waste Isolation Pilot Plant (WIPP) Compliance Certification Application (CCA) Performance Assessment (PA) used a relational database that was originally designed only to supply the input parameters required for implementation of the PA codes. Reviewers used the database as a point of entry to audit quality assurance measures for control, traceability, and retrievability of input information used for analysis, and output/work products. During these audits it became apparent that modifications to the architecture and scope of the database would benefit the EPA regulator and other stakeholders when reviewing the recertification application. This paper contains a discussion of the WPP PA CCA database and lessons learned for designing a database.

  15. The GlueX central drift chamber: Design and performance

    SciTech Connect

    Van Haarlem, Y; Barbosa, F; Dey, B; Lawrence, D; Razmyslovich, V; Smith, Visser; Whitlatch, T; Wilkin, G; Zihlmann, B

    2010-10-01

    Tests and studies concerning the design and performance of the GlueX Central Drift Chamber (CDC) are presented. A full-scale prototype was built to test and steer the mechanical and electronic design. Small scale prototypes were constructed to test for sagging and to do timing and resolution studies of the detector. These studies were used to choose the gas mixture and to program a Monte Carlo simulation that can predict the detector response in an external magnetic field. Particle identification and charge division possibilities were also investigated.

  16. Design theory and performance of cryogenic molecular adsorption refrigeration systems

    NASA Technical Reports Server (NTRS)

    Hartwig, W. H.; Woltman, A. W.; Masson, J. P.

    1978-01-01

    Closed-cycle operation of molecular adsorption refrigeration systems (MARS) has been demonstrated by using thermally cycled zeolites to adsorb and desorb various gases under pressures of 20-60 atm. This paper develops three aspects of the design theory: the physical theory of molecular adsorption of small molecules such as A, N2, N2O and NH3, the design relations for closed-cycle flow for three or more compressors, and the coefficient of performance. This work is intended to demonstrate nonmechanical gas compression for various cryogenic gases than can compete with mechanical systems with a different mix of advantages and disadvantages.

  17. Performance of the Westinghouse WWER-1000 fuel design

    SciTech Connect

    Hoglund, J.; Riznychenko, O.; Latorre, Richard; Lashevych, P.

    2011-09-22

    In 2005 six (6) Westinghouse WWER-1000 Lead Test Assemblies (LTAs) were loaded in the South Ukraine Unit 3. This design has demonstrated full compatibility with resident fuel designs and all associated fuel handling and reactor components. Operations have further demonstrated adequacy of performance margins and the reliability requirements for multiple cycles of operation. The LTAs have now been discharged after completing the planned four cycles of operation and having reached an average assembly burnup in excess of 43 MWd/kgU. Results and concluding remarks from the post irradiation examination is provided in this paper.

  18. FEL Design Studies at LBNL: Activities and Plans

    SciTech Connect

    Corlett, John N.; Fawley, W.; Lidia, S.; Padmore, H.; Penn, G.; Pogorelov, I.; Qiang, J.; Sannibale, F.; Staples, J.; Steier, C.; Venturini, M.; Wan, W.; Wilcox, R.; Zholents, A.

    2007-03-01

    LBNL staff are currently pursuing R&D for future x-ray FELs, and participate in two FEL construction projects. Our strategy is to address the most fundamental challenges, which are the cost-drivers and performance limitations of FEL facilities. An internally funded R&D program is aimed at investigating accelerator physics and technologies in three key areas: (1) Theoretical study, modeling, and experimental development of low emittance, high quantum efficiency cathodes; (2) Design studies of electron beam delivery systems, including emittance manipulations, high-resolution modeling of 6-D phase space, and low-emittance beam transport; and (3) Design studies of optical manipulations of electron beams for seeded and SASE FELs, providing short x-ray pulses of variable duration, synchronous with the seed and pump laser sources, and also long transform-limited pulses with a narrow bandwidth. Design studies of means for production of attosecond x-ray pulses at various wavelengths. We are collaborators in the FERMI{at}Elettra seeded FEL facility under construction at Sincrotrone Trieste, Italy, participating in accelerator design and FEL physics studies, and mechanical and electrical engineering. We are participating in the LCLS project at SLAC, implementing our design of stabilized timing and synchronization systems. Here we outline our long-term objectives, and current activities.

  19. American Literature: Performance Objectives and Classroom Activities.

    ERIC Educational Resources Information Center

    Ascher, Hope; And Others

    This guide is a sampler of ideas and activities based on 22 minimum objectives in speech, reading, writing, and research that have been identified for American literature study. Many of the activities involve an integration of several skills that are cross-referenced to other skills in the margins of the guide. A separate section on research…

  20. On the modified active region design of interband cascade lasers

    SciTech Connect

    Motyka, M.; Ryczko, K.; Dyksik, M.; Sęk, G.; Misiewicz, J.; Weih, R.; Dallner, M.; Kamp, M.; Höfling, S.

    2015-02-28

    Type II InAs/GaInSb quantum wells (QWs) grown on GaSb or InAs substrates and designed to be integrated in the active region of interband cascade lasers (ICLs) emitting in the mid infrared have been investigated. Optical spectroscopy, combined with band structure calculations, has been used to probe their electronic properties. A design with multiple InAs QWs has been compared with the more common double W-shaped QW and it has been demonstrated that it allows red shifting the emission wavelength and enhancing the transition oscillator strength. This can be beneficial for the improvements of the ICLs performances, especially when considering their long-wavelength operation.

  1. Simplified seismic performance assessment and implications for seismic design

    NASA Astrophysics Data System (ADS)

    Sullivan, Timothy J.; Welch, David P.; Calvi, Gian Michele

    2014-08-01

    The last decade or so has seen the development of refined performance-based earthquake engineering (PBEE) approaches that now provide a framework for estimation of a range of important decision variables, such as repair costs, repair time and number of casualties. This paper reviews current tools for PBEE, including the PACT software, and examines the possibility of extending the innovative displacement-based assessment approach as a simplified structural analysis option for performance assessment. Details of the displacement-based s+eismic assessment method are reviewed and a simple means of quickly assessing multiple hazard levels is proposed. Furthermore, proposals for a simple definition of collapse fragility and relations between equivalent single-degree-of-freedom characteristics and multi-degree-of-freedom story drift and floor acceleration demands are discussed, highlighting needs for future research. To illustrate the potential of the methodology, performance measures obtained from the simplified method are compared with those computed using the results of incremental dynamic analyses within the PEER performance-based earthquake engineering framework, applied to a benchmark building. The comparison illustrates that the simplified method could be a very effective conceptual seismic design tool. The advantages and disadvantages of the simplified approach are discussed and potential implications of advanced seismic performance assessments for conceptual seismic design are highlighted through examination of different case study scenarios including different structural configurations.

  2. Biotechnology-based odour control: design criteria and performance data.

    PubMed

    Quigley, C; Easter, C; Burrowes, P; Witherspoon, J

    2004-01-01

    As neighbouring areas continue to encroach upon wastewater treatment plants, there is an increasing need for odour control to mitigate potential negative offsite odorous impacts. One technology that is gaining widespread acceptance is biotechnology, which utilises the inherent ability of certain microorganisms to biodegrade offensive odorous compounds. Two main advantages of this form of treatment over other odour control technologies include the absence of hazardous chemicals and relatively low operation and maintenance requirements. The purpose of this paper is to provide information related to odour control design criteria used in sizing/selecting biotechnology-based odour control technologies, and to provide odour removal performance data obtained from several different biotechnology-based odour control systems. CH2M HILL has collected biotechnology-based odour control performance data over the last several years in order to track the continued performance of various biofilters and biotowers over time. Specifically, odour removal performance data have been collected from soil-, organic- and inorganic-media biofilters and inert inorganic media biotowers. Results indicate that biotechnology-based odour control is a viable and consistent technology capable of achieving high removal performance for odour and hydrogen sulphide. It is anticipated that the information presented in this paper will be of interest to anyone involved with odour control technology evaluation/selection or design review.

  3. Biotechnology-based odour control: design criteria and performance data.

    PubMed

    Quigley, C; Easter, C; Burrowes, P; Witherspoon, J

    2004-01-01

    As neighbouring areas continue to encroach upon wastewater treatment plants, there is an increasing need for odour control to mitigate potential negative offsite odorous impacts. One technology that is gaining widespread acceptance is biotechnology, which utilises the inherent ability of certain microorganisms to biodegrade offensive odorous compounds. Two main advantages of this form of treatment over other odour control technologies include the absence of hazardous chemicals and relatively low operation and maintenance requirements. The purpose of this paper is to provide information related to odour control design criteria used in sizing/selecting biotechnology-based odour control technologies, and to provide odour removal performance data obtained from several different biotechnology-based odour control systems. CH2M HILL has collected biotechnology-based odour control performance data over the last several years in order to track the continued performance of various biofilters and biotowers over time. Specifically, odour removal performance data have been collected from soil-, organic- and inorganic-media biofilters and inert inorganic media biotowers. Results indicate that biotechnology-based odour control is a viable and consistent technology capable of achieving high removal performance for odour and hydrogen sulphide. It is anticipated that the information presented in this paper will be of interest to anyone involved with odour control technology evaluation/selection or design review. PMID:15484776

  4. Performance evaluation of salivary amylase activity monitor.

    PubMed

    Yamaguchi, Masaki; Kanemori, Takahiro; Kanemaru, Masashi; Takai, Noriyasu; Mizuno, Yasufumi; Yoshida, Hiroshi

    2004-10-15

    In order to quantify psychological stress and to distinguish eustress and distress, we have been investigating the establishment of a method that can quantify salivary amylase activity (SMA). Salivary glands not only act as amplifiers of a low level of norepinephrine, but also respond more quickly and sensitively to psychological stress than cortisol levels. Moreover, the time-course changes of the salivary amylase activity have a possibility to distinguish eustress and distress. Thus, salivary amylase activity can be utilized as an excellent index for psychological stress. However, in dry chemistry system, a method for quantification of the enzymatic activity still needs to be established that can provide with sufficient substrate in a testing tape as well as can control enzymatic reaction time. Moreover, it is necessary to develop a method that has the advantages of using saliva, such as ease of collection, rapidity of response, and able to use at any time. In order to establish an easy method to monitor the salivary amylase activity, a salivary transcription device was fabricated to control the enzymatic reaction time. A fabricated salivary amylase activity monitor consisted of three devices, the salivary transcription device, a testing-strip and an optical analyzer. By adding maltose as a competitive inhibitor to a substrate Ga1-G2-CNP, a broad-range activity testing-strip was fabricated that could measure the salivary amylase activity with a range of 0-200 kU/l within 150 s. The calibration curve of the monitor for the salivary amylase activity showed R2=0.941, indicating that it was possible to use this monitor for the analysis of the salivary amylase activity without the need to determine the salivary volume quantitatively. In order to evaluate the assay variability of the monitor, salivary amylase activity was measured using Kraepelin psychodiagnostic test as a psychological stressor. A significant difference of salivary amylase activity was recognized

  5. Sensor fusion methods for high performance active vibration isolation systems

    NASA Astrophysics Data System (ADS)

    Collette, C.; Matichard, F.

    2015-04-01

    Sensor noise often limits the performance of active vibration isolation systems. Inertial sensors used in such systems can be selected through a wide variety of instrument noise and size characteristics. However, the most sensitive instruments are often the biggest and the heaviest. Consequently, high-performance active isolators sometimes embed many tens of kilograms in instrumentation. The weight and size of instrumentation can add unwanted constraint on the design. It tends to lower the structures natural frequencies and reduces the collocation between sensors and actuators. Both effects tend to reduce feedback control performance and stability. This paper discusses sensor fusion techniques that can be used in order to increase the control bandwidth (and/or the stability). For this, the low noise inertial instrument signal dominates the fusion at low frequency to provide vibration isolation. Other types of sensors (relative motion, smaller but noisier inertial, or force sensors) are used at higher frequencies to increase stability. Several sensor fusion configurations are studied. The paper shows the improvement that can be expected for several case studies including a rigid equipment, a flexible equipment, and a flexible equipment mounted on a flexible support structure.

  6. Review of super Ni/Cd cell designs and performance

    NASA Technical Reports Server (NTRS)

    Abrams-Blakemore, Bruce

    1993-01-01

    Eagle-Picher Industries, Inc., in cooperation with Hughes Aircraft Company, began production of the Super Nickel-Cadmium cell in 1989. Since that time the Super Nickel-Cadmium cell has been deployed in a wide variety of satellites. This paper will review one of those programs and provide a performance update. We will discuss storage requirements and capacity histories for the various Super NiCad Cell designs.

  7. Design and performance of the Stanford Linear Collider Control System

    SciTech Connect

    Melen, R.E.

    1984-10-01

    The success of the Stanford Linear Collider (SLC) will be dependent upon the implementation of a very large advanced computer-based instrumentation and control system. This paper describes the architectural design of this system as well as a critique of its performance. This critique is based on experience obtained from its use in the control and monitoring of 1/3 of the SLAC linac and in support of an expensive experimental machine physics experimental program. 11 references, 3 figures.

  8. Voltage-Controlled Sapphire Oscillator: Design, Development, and Preliminary Performance

    NASA Astrophysics Data System (ADS)

    Wang, R. T.; Dick, G. J.; Tjoelker, R. L.

    2007-08-01

    We present the design for a new short-term frequency standard, the voltage-controlled sapphire oscillator, as a practical and lower-cost alternative to a cryogenic sapphire oscillator operating at liquid helium temperatures. Performance goals are a frequency stability of 1 x 10^-14 (1 second equal to or less than tau equal to or less than 100 seconds), more than 2 years of continuous operation, and practical operability. Key elements include the sapphire resonator, low-power and long-life cryocooler, frequency compensation method, and cryo-Pound design. We report the design verification, experimental results, and test results of the cryocooler environmental sensitivity, as well as a preliminary stability measurement.

  9. Design and performance of HEAD PENN-PET scanner

    SciTech Connect

    Freifelder, R.; Karp, J.S. . Dept. of Radiology); Geagan, M.; Muehllehner, G. )

    1994-08-01

    A new PET scanner for brain imaging (and animals) has been designed with very high sensitivity and spatial resolution. The design is an evolution of the PENN-PET scanner, which uses large position-sensitive NaI(Tl) detectors, with Anger-type positioning logic, and which allows 3-D volume imaging, without septa. The new design is built with a single annular crystal coupled to 180 photomultiplier tubes, and uses local triggering electronics to subdivide the detector into small zones and to determine coincident events within the detector. The axial acceptance angle of [+-] 27 deg, with a field-of-view of 25.6 cm, is larger than any currently operating PET scanner. Performance measurements are presented.

  10. Performance of Several Combustion Chambers Designed for Aircraft Oil Engines

    NASA Technical Reports Server (NTRS)

    Joachim, William F; Kemper, Carlton

    1928-01-01

    Several investigations have been made on single-cylinder test engines to determine the performance characteristics of four types of combustion chambers designed for aircraft oil engines. Two of the combustion chambers studied were bulb-type precombustion chambers, the connecting orifice of one having been designed to produce high turbulence by tangential air flow in both the precombustion chamber and the cylinder. The other two were integral combustion chambers, one being dome-shaped and the other pent-roof shaped. The injection systems used included cam and eccentric driven fuel pumps, and diaphragm and spring-loaded fuel-injection valves. A diaphragm type maximum cylinder pressure indicator was used in part of these investigations with which the cylinder pressures were controlled to definite valves. The performance of the engines when equipped with each of the combustion chambers is discussed. The best performance for the tests reported was obtained with a bulb-type combustion chamber designed to give a high degree of turbulence within the bulb and cylinder. (author)

  11. Comprehensive design of omnidirectional high-performance perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Zhang, Yutao; Xuan, Yimin

    2016-07-01

    The comprehensive design approach is established with coupled optical-electrical simulation for perovskite-based solar cell, which emerged as one of the most promising competitors to silicon solar cell for its low-cost fabrication and high PCE. The selection of structured surface, effect of geometry parameters, incident angle-dependence and polarization-sensitivity are considered in the simulation. The optical modeling is performed via the finite-difference time-domain method whilst the electrical properties are obtained by solving the coupled nonlinear equations of Poisson, continuity, and drift-diffusion equations. The optical and electrical performances of five different structured surfaces are compared to select a best structured surface for perovskite solar cell. The effects of the geometry parameters on the optical and electrical properties of the perovskite cell are analyzed. The results indicate that the light harvesting is obviously enhanced by the structured surface. The electrical performance can be remarkably improved due to the enhanced light harvesting of the designed best structured surface. The angle-dependence for s- and p-polarizations is investigated. The structured surface exhibits omnidirectional behavior and favorable polarization-insensitive feature within a wide incident angle range. Such a comprehensive design approach can highlight the potential of perovskite cell for power conversion in the full daylight.

  12. Comprehensive design of omnidirectional high-performance perovskite solar cells.

    PubMed

    Zhang, Yutao; Xuan, Yimin

    2016-01-01

    The comprehensive design approach is established with coupled optical-electrical simulation for perovskite-based solar cell, which emerged as one of the most promising competitors to silicon solar cell for its low-cost fabrication and high PCE. The selection of structured surface, effect of geometry parameters, incident angle-dependence and polarization-sensitivity are considered in the simulation. The optical modeling is performed via the finite-difference time-domain method whilst the electrical properties are obtained by solving the coupled nonlinear equations of Poisson, continuity, and drift-diffusion equations. The optical and electrical performances of five different structured surfaces are compared to select a best structured surface for perovskite solar cell. The effects of the geometry parameters on the optical and electrical properties of the perovskite cell are analyzed. The results indicate that the light harvesting is obviously enhanced by the structured surface. The electrical performance can be remarkably improved due to the enhanced light harvesting of the designed best structured surface. The angle-dependence for s- and p-polarizations is investigated. The structured surface exhibits omnidirectional behavior and favorable polarization-insensitive feature within a wide incident angle range. Such a comprehensive design approach can highlight the potential of perovskite cell for power conversion in the full daylight. PMID:27405419

  13. Comprehensive design of omnidirectional high-performance perovskite solar cells

    PubMed Central

    Zhang, Yutao; Xuan, Yimin

    2016-01-01

    The comprehensive design approach is established with coupled optical-electrical simulation for perovskite-based solar cell, which emerged as one of the most promising competitors to silicon solar cell for its low-cost fabrication and high PCE. The selection of structured surface, effect of geometry parameters, incident angle-dependence and polarization-sensitivity are considered in the simulation. The optical modeling is performed via the finite-difference time-domain method whilst the electrical properties are obtained by solving the coupled nonlinear equations of Poisson, continuity, and drift-diffusion equations. The optical and electrical performances of five different structured surfaces are compared to select a best structured surface for perovskite solar cell. The effects of the geometry parameters on the optical and electrical properties of the perovskite cell are analyzed. The results indicate that the light harvesting is obviously enhanced by the structured surface. The electrical performance can be remarkably improved due to the enhanced light harvesting of the designed best structured surface. The angle-dependence for s- and p-polarizations is investigated. The structured surface exhibits omnidirectional behavior and favorable polarization-insensitive feature within a wide incident angle range. Such a comprehensive design approach can highlight the potential of perovskite cell for power conversion in the full daylight. PMID:27405419

  14. Impact of separator design on battery performance in traction applications

    NASA Astrophysics Data System (ADS)

    Brilmyer, G. H.

    The lead-acid battery continues to be the battery of choice for traction applications. Golf carts, lift-trucks and automatic guided vehicles are only a few of the traction-related markets which depend on the lead-acid battery for their continued growth and success. Throughout the world, traction battery manufacturers use a wide range of grid designs, grid alloys, paste formulations, separators and other features to optimize the deep-cycle performance of their products. In this complex array of design features, the least understood parameter is most likely the battery separator. Though somewhat inconspicuous by nature, the traction-battery separator can, if properly selected, play a key role in performance, by extending the life of both the positive and negative plates while at the same time reducing battery maintenance and power requirements for recharging. This paper discusses the various design features of a battery separator and describes how such features may be used to effect the performance and life of the traction battery. Separator porosity, material composition, backweb thickness, rib dimensions and the use of attached glass mats are some of the controlled variables.

  15. Portable oxygen subsystem. [design analysis and performance tests

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The concept and design of a portable oxygen device for use in the space shuttle orbiter is presented. Hardware fabrication and acceptance tests (i.e., breadboard models) are outlined and discussed. Optimization of the system (for weight, volume, safety, costs) is discussed. The device is of the rebreather type, and provides a revitalized breathing gas supply to a crewman for denitrogenization and emergency activities. Engineering drawings and photographs of the device are shown.

  16. Atomic hydrogen maser active oscillator cavity and bulb design optimization

    NASA Technical Reports Server (NTRS)

    Peters, H. E.; Washburn, P. J.

    1984-01-01

    The performance characteristics and reliability of the active oscillator atomic hydrogen maser depend upon oscillation parameters which characterize the interaction region of the maser, the resonant cavity and atom storage bulb assembly. With particular attention to use of the cavity frequency switching servo (1) to reduce cavity pulling, it is important to maintain high oscillation level, high atomic beam flux utilization efficiency, small spin exchange parameter and high cavity quality factor. It is also desirable to have a small and rigid cavity and bulb structure and to minimize the cavity temperature sensitivity. Curves for a novel hydrogen maser cavity configuration which is partially loaded with a quartz dielectric cylinder and show the relationships between cavity length, cavity diameter, bulb size, dielectric thickness, cavity quality factor, filling factor and cavity frequency temperature coefficient are presented. The results are discussed in terms of improvement in maser performance resulting from particular design choices.

  17. Preliminary design activities for solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Information on the development of solar heating and cooling systems is presented. The major emphasis is placed on program organization, system size definition, site identification, system approaches, heat pump and equipment design, collector procurement, and other preliminary design activities.

  18. Using biological performance similarity to inform disaccharide library design

    PubMed Central

    Tanikawa, Tetsuya; Fridman, Micha; Zhu, Wenjiang; Faulk, Brian; Joseph, Isaac C.; Kahne, Daniel; Wagner, Bridget K.; Clemons, Paul A.

    2009-01-01

    Diversity-oriented organic synthesis (DOS) is a strategy to make compound collections to probe biological systems1-7. Designing better DOS libraries requires having methods to assess the consequences of different synthesis decisions on the biological performance of resulting library members8. Since we are particularly interested in how stereochemistry affects performance in biological assays, we prepared a disaccharide library containing systematic stereochemical variations, assayed the library for different biological effects, and developed methods to assess the similarity of performance between members across multiple assays. These methods allow us to ask which subsets of stereochemical features best predict similarity in patterns of biological performance between individual members and which features produce the greatest variation of outcomes. We anticipate that the data-analysis approach presented here can be generalized to other sets of biological assays and other chemical descriptors. Methods to assess which structural features of library members produce the greatest similarity in performance for a given set of biological assays should help prioritize synthesis decisions in second-generation library development targeting the underlying cell-biological processes. Methods to assess which structural features of library members produce the greatest variation in performance should help guide decisions about what synthetic methods need to be developed to make optimal small-molecule screening collections. PMID:19298063

  19. Using biological performance similarity to inform disaccharide library design.

    PubMed

    Tanikawa, Tetsuya; Fridman, Micha; Zhu, Wenjiang; Faulk, Brian; Joseph, Isaac C; Kahne, Daniel; Wagner, Bridget K; Clemons, Paul A

    2009-04-15

    Designing better small-molecule discovery libraries requires having methods to assess the consequences of different synthesis decisions on the biological performance of resulting library members. Since we are particularly interested in how stereochemistry affects performance in biological assays, we prepared a disaccharide library containing systematic stereochemical variations, assayed the library for different biological effects, and developed methods to assess the similarity of performance between members across multiple assays. These methods allow us to ask which subsets of stereochemical features best predict similarity in patterns of biological performance between individual members and which features produce the greatest variation of outcomes. We anticipate that the data-analysis approach presented here can be generalized to other sets of biological assays and other chemical descriptors. Methods to assess which structural features of library members produce the greatest similarity in performance for a given set of biological assays should help prioritize synthesis decisions in second-generation library development targeting the underlying cell-biological processes. Methods to assess which structural features of library members produce the greatest variation in performance should help guide decisions about what synthetic methods need to be developed to make optimal small-molecule screening collections.

  20. Statistical Performances of Resistive Active Power Splitter

    NASA Astrophysics Data System (ADS)

    Lalléchère, Sébastien; Ravelo, Blaise; Thakur, Atul

    2016-03-01

    In this paper, the synthesis and sensitivity analysis of an active power splitter (PWS) is proposed. It is based on the active cell composed of a Field Effect Transistor in cascade with shunted resistor at the input and the output (resistive amplifier topology). The PWS uncertainty versus resistance tolerances is suggested by using stochastic method. Furthermore, with the proposed topology, we can control easily the device gain while varying a resistance. This provides useful tool to analyse the statistical sensitivity of the system in uncertain environment.

  1. Moving bed biofilm reactor technology: process applications, design, and performance.

    PubMed

    McQuarrie, James P; Boltz, Joshua P

    2011-06-01

    The moving bed biofilm reactor (MBBR) can operate as a 2- (anoxic) or 3-(aerobic) phase system with buoyant free-moving plastic biofilm carriers. These systems can be used for municipal and industrial wastewater treatment, aquaculture, potable water denitrification, and, in roughing, secondary, tertiary, and sidestream applications. The system includes a submerged biofilm reactor and liquid-solids separation unit. The MBBR process benefits include the following: (1) capacity to meet treatment objectives similar to activated sludge systems with respect to carbon-oxidation and nitrogen removal, but requires a smaller tank volume than a clarifier-coupled activated sludge system; (2) biomass retention is clarifier-independent and solids loading to the liquid-solids separation unit is reduced significantly when compared with activated sludge systems; (3) the MBBR is a continuous-flow process that does not require a special operational cycle for biofilm thickness, L(F), control (e.g., biologically active filter backwashing); and (4) liquid-solids separation can be achieved with a variety of processes, including conventional and compact high-rate processes. Information related to system design is fragmented and poorly documented. This paper seeks to address this issue by summarizing state-of-the art MBBR design procedures and providing the reader with an overview of some commercially available systems and their components. PMID:21751715

  2. Moving bed biofilm reactor technology: process applications, design, and performance.

    PubMed

    McQuarrie, James P; Boltz, Joshua P

    2011-06-01

    The moving bed biofilm reactor (MBBR) can operate as a 2- (anoxic) or 3-(aerobic) phase system with buoyant free-moving plastic biofilm carriers. These systems can be used for municipal and industrial wastewater treatment, aquaculture, potable water denitrification, and, in roughing, secondary, tertiary, and sidestream applications. The system includes a submerged biofilm reactor and liquid-solids separation unit. The MBBR process benefits include the following: (1) capacity to meet treatment objectives similar to activated sludge systems with respect to carbon-oxidation and nitrogen removal, but requires a smaller tank volume than a clarifier-coupled activated sludge system; (2) biomass retention is clarifier-independent and solids loading to the liquid-solids separation unit is reduced significantly when compared with activated sludge systems; (3) the MBBR is a continuous-flow process that does not require a special operational cycle for biofilm thickness, L(F), control (e.g., biologically active filter backwashing); and (4) liquid-solids separation can be achieved with a variety of processes, including conventional and compact high-rate processes. Information related to system design is fragmented and poorly documented. This paper seeks to address this issue by summarizing state-of-the art MBBR design procedures and providing the reader with an overview of some commercially available systems and their components.

  3. Design requirements document for project W-520, immobilized low-activity waste disposal

    SciTech Connect

    Ashworth, S.C.

    1998-08-06

    This design requirements document (DRD) identifies the functions that must be performed to accept, handle, and dispose of the immobilized low-activity waste (ILAW) produced by the Tank Waste Remediation System (TWRS) private treatment contractors and close the facility. It identifies the requirements that are associated with those functions and that must be met. The functional and performance requirements in this document provide the basis for the conceptual design of the Tank Waste Remediation System Immobilized Low-Activity Waste disposal facility project (W-520) and provides traceability from the program-level requirements to the project design activity.

  4. Prescribed Active Learning Increases Performance in Introductory Biology

    PubMed Central

    O'Connor, Eileen; Parks, John W.; Cunningham, Matthew; Hurley, David; Haak, David; Dirks, Clarissa; Wenderoth, Mary Pat

    2007-01-01

    We tested five course designs that varied in the structure of daily and weekly active-learning exercises in an attempt to lower the traditionally high failure rate in a gateway course for biology majors. Students were given daily multiple-choice questions and answered with electronic response devices (clickers) or cards. Card responses were ungraded; clicker responses were graded for right/wrong answers or participation. Weekly practice exams were done as an individual or as part of a study group. Compared with previous versions of the same course taught by the same instructor, students in the new course designs performed better: There were significantly lower failure rates, higher total exam points, and higher scores on an identical midterm. Attendance was higher in the clicker versus cards section; attendance and course grade were positively correlated. Students did better on clicker questions if they were graded for right/wrong answers versus participation, although this improvement did not translate into increased scores on exams. In this course, achievement increases when students get regular practice via prescribed (graded) active-learning exercises. PMID:17548875

  5. Prescribed active learning increases performance in introductory biology.

    PubMed

    Freeman, Scott; O'Connor, Eileen; Parks, John W; Cunningham, Matthew; Hurley, David; Haak, David; Dirks, Clarissa; Wenderoth, Mary Pat

    2007-01-01

    We tested five course designs that varied in the structure of daily and weekly active-learning exercises in an attempt to lower the traditionally high failure rate in a gateway course for biology majors. Students were given daily multiple-choice questions and answered with electronic response devices (clickers) or cards. Card responses were ungraded; clicker responses were graded for right/wrong answers or participation. Weekly practice exams were done as an individual or as part of a study group. Compared with previous versions of the same course taught by the same instructor, students in the new course designs performed better: There were significantly lower failure rates, higher total exam points, and higher scores on an identical midterm. Attendance was higher in the clicker versus cards section; attendance and course grade were positively correlated. Students did better on clicker questions if they were graded for right/wrong answers versus participation, although this improvement did not translate into increased scores on exams. In this course, achievement increases when students get regular practice via prescribed (graded) active-learning exercises.

  6. Optimal design of active and semi-active suspensions including time delays and preview

    NASA Astrophysics Data System (ADS)

    Hac', A.; Youn, I.

    1993-10-01

    Several control laws for active and semi-active suspension based on a linear half car model are derived and investigated. The strategies proposed take full advantage of the fact that the road input to the rear wheels is a delayed version of that to the front wheels, which in turn can be obtained either from the measurements of the front wheels and body motions or by direct preview of road irregularities if preview sensors are available. The suspension systems are optimized with respect to ride comfort, road holding and suspension rattle space as expressed by the mean-square-values of body acceleration (including effects of heave and pitch), tire deflections and front and rear suspension travels. The optimal control laws that minimize the given performance index and include passivity constraints in the semi-active case are derived using calculus of variation. The optimal semi-active suspension becomes piecewise linear, varying between passive and fully active systems and combinations of them. The performances of active and semi-active systems with and without preview were evaluated by numerical simulation in the time and frequency domains. The results show that incorporation of time delay between the front and rear axles in controller design improves the dynamic behavior of the rear axle and control of body pitch motion, while additional preview improves front wheel dynamics and body heave.

  7. Thermionic in-core heat pipe design and performance

    NASA Astrophysics Data System (ADS)

    Determan, W. R.; Hagelston, G.

    1992-01-01

    The heat pipe cooled thermionic reactor (HPTI) relies on in-core sodium heat pipes to provide a redundant means of cooling the 72 thermionic fuel elements (TFEs) and 36 driver fuel pins which comprise the 40 kWe core assembly. In-core heat pipe cooling was selected for the reactor design to meet the requirements for a system design with the potential to achieve a high survivability level against natural and man-made threats and one that possesses no-mission ending single point failures. A detailed study was performed to determine the potential in-core heat pipe geometries which could be developed for an HPTI concept. Requirements and performance estimates were developed for two in-core heat pipe geometries. Both nominal and faulted operating conditions were evaluated using a two-dimensional thermal model of the core to assess TFE and driver fuel pin temperature profiles. A bow tie in-core heat pipe geometry was selected as the optimum design using a HPTI honeycomb core structure.

  8. Research in the design of high-performance reconfigurable systems

    NASA Technical Reports Server (NTRS)

    Slotnick, D. L.; Mcewan, S. D.; Spry, A. J.

    1984-01-01

    An initial design for the Bit Processor (BP) referred to in prior reports as the Processing Element or PE has been completed. Eight BP's, together with their supporting random-access memory, a 64 k x 9 ROM to perform addition, routing logic, and some additional logic, constitute the components of a single stage. An initial stage design is given. Stages may be combined to perform high-speed fixed or floating point arithmetic. Stages can be configured into a range of arithmetic modules that includes bit-serial one or two-dimensional arrays; one or two dimensional arrays fixed or floating point processors; and specialized uniprocessors, such as long-word arithmetic units. One to eight BP's represent a likely initial chip level. The Stage would then correspond to a first-level pluggable module. As both this project and VLSI CAD/CAM progress, however, it is expected that the chip level would migrate upward to the stage and, perhaps, ultimately the box level. The BP RAM, consisting of two banks, holds only operands and indices. Programs are at the box (high-level function) and system level. At the system level initial effort has been concentrated on specifying the tools needed to evaluate design alternatives.

  9. 40 CFR 63.5850 - How do I conduct performance tests, performance evaluations, and design evaluations?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...: Reinforced Plastic Composites Production Testing and Initial Compliance Requirements § 63.5850 How do I... test, performance evaluation, and design evaluation in 40 CFR part 63, subpart SS, that applies to you... requirements in § 63.7(e)(1) and under the specific conditions that 40 CFR part 63, subpart SS, specifies....

  10. 40 CFR 63.5850 - How do I conduct performance tests, performance evaluations, and design evaluations?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... test, performance evaluation, and design evaluation in 40 CFR part 63, subpart SS, that applies to you... requirements in § 63.7(e)(1) and under the specific conditions that 40 CFR part 63, subpart SS, specifies. (c... and under the specific conditions that 40 CFR part 63, subpart SS, specifies. (d) You may not...

  11. Do Performance-Based Codes Support Universal Design in Architecture?

    PubMed

    Grangaard, Sidse; Frandsen, Anne Kathrine

    2016-01-01

    The research project 'An analysis of the accessibility requirements' studies how Danish architectural firms experience the accessibility requirements of the Danish Building Regulations and it examines their opinions on how future regulative models can support innovative and inclusive design - Universal Design (UD). The empirical material consists of input from six workshops to which all 700 Danish Architectural firms were invited, as well as eight group interviews. The analysis shows that the current prescriptive requirements are criticized for being too homogenous and possibilities for differentiation and zoning are required. Therefore, a majority of professionals are interested in a performance-based model because they think that such a model will support 'accessibility zoning', achieving flexibility because of different levels of accessibility in a building due to its performance. The common understanding of accessibility and UD is directly related to buildings like hospitals and care centers. When the objective is both innovative and inclusive architecture, the request of a performance-based model should be followed up by a knowledge enhancement effort in the building sector. Bloom's taxonomy of educational objectives is suggested as a tool for such a boost. The research project has been financed by the Danish Transport and Construction Agency. PMID:27534292

  12. Do Performance-Based Codes Support Universal Design in Architecture?

    PubMed

    Grangaard, Sidse; Frandsen, Anne Kathrine

    2016-01-01

    The research project 'An analysis of the accessibility requirements' studies how Danish architectural firms experience the accessibility requirements of the Danish Building Regulations and it examines their opinions on how future regulative models can support innovative and inclusive design - Universal Design (UD). The empirical material consists of input from six workshops to which all 700 Danish Architectural firms were invited, as well as eight group interviews. The analysis shows that the current prescriptive requirements are criticized for being too homogenous and possibilities for differentiation and zoning are required. Therefore, a majority of professionals are interested in a performance-based model because they think that such a model will support 'accessibility zoning', achieving flexibility because of different levels of accessibility in a building due to its performance. The common understanding of accessibility and UD is directly related to buildings like hospitals and care centers. When the objective is both innovative and inclusive architecture, the request of a performance-based model should be followed up by a knowledge enhancement effort in the building sector. Bloom's taxonomy of educational objectives is suggested as a tool for such a boost. The research project has been financed by the Danish Transport and Construction Agency.

  13. Design and performance of the ESA Optical Ground Station

    NASA Astrophysics Data System (ADS)

    Reyes Garcia-Talavera, Marcos; Rodriguez, Jose A.; Viera, Teodora; Moreno-Arce, Heidi; Rasilla, Jose L.; Gago, Fernando; Rodriguez, Luis F.; Gomez, Panchita; Ballesteros Ramirez, Ezequiel

    2002-04-01

    The European Space Agency (ESA) has undertaken the development of Optical Data Relay payloads, aimed at establishing free space optical communication links between satellites. The first of such systems put into orbit is the SILEX project, in which an experimental link between a GEO satellite (ARTEMIS) and a LEO satellite (SPOT IV) will be used to relay earth observation data. In order to perform In Orbit Testing (IOT) of these and future optical communications systems, ESA and the Instituto de Astrofisica de Canarias (IAC) reached an agreement for the building of the Optical Ground Station (OGS) in the IAC Teide Observatory, which consists basically of a 1-meter telescope and the suitable instrumentation for establishing and testing bi-directional optical links with satellites. The presence of the atmosphere in the data path posses particular problems, with an impact on the instrumentation design. The transmission, reception and measurement functions, along with the overall control of the instruments, are performed at OGS by the Focal Plane Control Electronics (FPCE). The design and performance of this instrumentation is presented, emphasizing the Pointing, Acquisition and Tracking, the Tuneable Laser and the Master Control.

  14. Integrated design of castings: effect of porosity on mechanical performance

    NASA Astrophysics Data System (ADS)

    Hardin, R. A.; Beckermann, C.

    2012-07-01

    Porosity can significantly reduce the strength and durability of castings in service. An integrated design approach has been developed where casting simulation is combined with mechanical performance simulations. Predictions of the porosity distribution from the casting process simulation are transferred to and used in stress and fatigue life simulations. Thus, the effect of casting quality on service performance can be evaluated. Results of a study are presented where the measured porosity distribution in cast steel specimens is transferred to an elasto-plastic finite-element stress analysis model. Methods are developed to locally reduce the mechanical properties according to the porosity present, without having to resolve individual pores. Plastic deformation is modeled using porous metal plasticity theory. The predictions are compared to tensile measurements performed on the specimens. The complex deformations and the reductions in the ductility of the specimens due to porosity are predicted well. The predicted stresses are transferred to a fatigue analysis code that takes the porosity distribution into account as well. The measured and predicted fatigue lives are also in good agreement. Finally, the results of a case study are presented that illustrate the utility of the present integrated approach in optimizing the design of a steel casting.

  15. Design and Implementation of Alkali Activated Cement For Sustainable Development

    NASA Astrophysics Data System (ADS)

    Moseson, Alexander James

    Herein, progress is presented on the design and implementation of technology for sustainable development in general and international development in particular. Necessarily interdisciplinary, the work draws upon the tools and techniques of Mechanical, Materials, and Civil Engineering; and History & Politics. The work was conducted along two paths, the first being the theory and methodology of sustainable development. A flexible design and dissemination framework was developed, Technology Seeding, defined as: development by the transfer and participatory adaptation of appropriate proven conceptual designs. The methodology was developed in part through two case studies which implemented, respectively, wood-turning lathes in Tanzania and upland rice planters in Thailand. The second path is the design and investigation of alkali-activated cements (AACs) for practical use. Those developed herein, for US markets, comprise ground granulated blast furnace slag, soda ash (sodium carbonate), and up to 68 wt.% granular limestone. Mixture Design of Experiment (DOE) was utilized to guide empirical and theoretical analysis of performance (e.g. compressive strength), economic & ecological aspects (e.g. cost, CO2 production, energy consumption), and chemistry (e.g. Rietveld analysis of x-ray diffractograms). Models were derived to understand the impact of mix design on performance and for optimization. Successful formulations are hydraulic and cure at room temperature, with strengths as high as 41 MPa at 3 days and 65 MPa at 28 days. Some of these formulations, compared to OPC, are competitive in performance, reduce cost by up to 40%, and reduce both CO2 production and energy consumption by up to 97%. Major chemical products include calcium silicate hydrates / calcium aluminum silicate hydrates (C-(A)-S-H), gaylussite, and calcite (both newly formed and remaining from limestone). Calcite/dolomite and C-(A)-S-H both contribute to strength. A fraction of the limestone is consumed

  16. Design and performance of a prototype fuel cell powered vehicle

    SciTech Connect

    Lehman, P.A.; Chamberlin, C.E.

    1996-12-31

    The Schatz Energy Research Center (SERC) is now engaged in the Palm Desert Renewable Hydrogen Transportation System Project. The Project involves a consortium which includes the City of Palm Desert, SERC, the U.S. Department of Energy, the South Coast Air Quality Management District, and Sandia and Lawrence Livermore National Laboratories. Its goal to develop a clean and sustainable transportation system for a community will be accomplished by producing a fleet of fuel cell vehicles, installing a refueling infrastructure utilizing hydrogen generated from solar and wind power, and developing and staffing a fuel cell service and diagnostic center. We will describe details of the project and performance goals for the fuel cell vehicles and associated peripheral systems. In the past year during the first stage in the project, SERC has designed and built a prototype fuel cell powered personal utility vehicle (PUV). These steps included: (1) Designing, building, and testing a 4.0 kW proton exchange membrane (PEM) fuel cell as a power plant for the PUV. (2) Designing, building and testing peripherals including the air delivery, fuel storage/delivery, refueling, water circulation, cooling, and electrical systems. (3) Devising a control algorithm for the fuel cell power plant in the PUV. (4) Designing and building a test bench in which running conditions in the PUV could be simulated and the fuel cell and its peripheral systems tested. (5) Installing an onboard computer and associated electronics into the PUV (6) Assembling and road testing the PUV.

  17. Controller design and performance of the Spacelab instrument pointing system

    NASA Astrophysics Data System (ADS)

    Woelker, A.

    The Spacelab instrument pointing system (IPS) is designed for high-precision pointing of space experiments. The IPS demonstrated its performance during the maiden flight on the Shuttle in July 1985. The control system provides three-axis pointing and stabilization in the arcsec range for a variety of experiments. The envisaged pointing accuracy as well as the structural flexibility of the plant and disturbances imposed challenging requirements on the controller design. The control system comprises a feedback loop with attenuation filters and PID control as well as feed-forward compensation of external disturbances. Based on optical sensor and gyro measurements the attitude is determined via a special version of the Kalman filter.

  18. Design features and performance of a high speed TDMA demodulator

    NASA Astrophysics Data System (ADS)

    Wallace, R. L.

    This paper describes the major design features used in a high-speed, burst-type TDMA demodulator, capable of supporting data rates up to 90MBS. The major features discused are as follows: burst to burst fast settling AGC Loop; a times four (X4) Carrier Recovery scheme with an AFC tracking loop and double filter/multiplier phase cancellation; I.F. half symbol delay/multiply Symbol Timing Recovery; baseband implementation of NYQUIST/matched filtering techniques; and a time-sampled, digital implementation of a COSTAS recovered carrier phasing loop. The actual performance characteristics of the demodulator design operating at 70MHZ I.F. frequency and a data rate of 48MBS are presented.

  19. KEPLER MISSION DESIGN, REALIZED PHOTOMETRIC PERFORMANCE, AND EARLY SCIENCE

    SciTech Connect

    Koch, David G.; Borucki, William J.; Lissauer, Jack J.; Basri, Gibor; Marcy, Geoffrey; Batalha, Natalie M.; Brown, Timothy M.; Caldwell, Douglas; DeVore, Edna; Jenkins, Jon; Christensen-Dalsgaard, Joergen; Cochran, William D.; Dunham, Edward W.; Gautier, Thomas N.; Gilliland, Ronald L.; Gould, Alan; Kondo, Yoji; Monet, David

    2010-04-20

    The Kepler Mission, launched on 2009 March 6, was designed with the explicit capability to detect Earth-size planets in the habitable zone of solar-like stars using the transit photometry method. Results from just 43 days of data along with ground-based follow-up observations have identified five new transiting planets with measurements of their masses, radii, and orbital periods. Many aspects of stellar astrophysics also benefit from the unique, precise, extended, and nearly continuous data set for a large number and variety of stars. Early results for classical variables and eclipsing stars show great promise. To fully understand the methodology, processes, and eventually the results from the mission, we present the underlying rationale that ultimately led to the flight and ground system designs used to achieve the exquisite photometric performance. As an example of the initial photometric results, we present variability measurements that can be used to distinguish dwarf stars from red giants.

  20. A human performance evaluation of graphic symbol-design features.

    PubMed

    Samet, M G; Geiselman, R E; Landee, B M

    1982-06-01

    16 subjects learned each of two tactical display symbol sets (conventional symbols and iconic symbols) in turn and were then shown a series of graphic displays containing various symbol configurations. For each display, the subject was asked questions corresponding to different behavioral processes relating to symbol use (identification, search, comparison, pattern recognition). The results indicated that: (a) conventional symbols yielded faster pattern-recognition performance than iconic symbols, and iconic symbols did not yield faster identification than conventional symbols, and (b) the portrayal of additional feature information (through the use of perimeter density or vector projection coding) slowed processing of the core symbol information in four tasks, but certain symbol-design features created less perceptual interference and had greater correspondence with the portrayal of specific tactical concepts than others. The results were discussed in terms of the complexities involved in the selection of symbol design features for use in graphic tactical displays.

  1. RICH detector at Jefferson Lab, design, performance and physics results

    SciTech Connect

    E. Cisbani; S. Colilli; F. Cusanno; S. Frullani; R. Frantoni; F. Garibaldi; F. Giuliani; M. Gricia; M. Lucentini; M.L. Magliozzi; L. Pierangeli; F. Santavenere; P. Veneroni; G.M. Urciuoli; M. Iodice; G. De Cataldo; R. De Leo; L. Lagamba; S. Marrone; E. Nappi; V. Paticchio; R. Feuerbach; D. Higinbotham; J. Lerose; B. Kross; R. Michaels; Y. Qiang; B. Reitz; J. Segal; B. Wojtsekhowski; C. Zorn; A. Acha; P. Markowitz; C.C. Chang; H. Breuer

    2006-04-01

    Since 2004 the hadron spectrometer of Hall A at Jefferson Lab is equipped with a proximity focusing RICH. This detector is capable of identify kaon from pion and proton with an angular separation starting from 6 sigma at 2 GeV/c. The RICH design is conceptually similar to the ALICE HMPID RICH; it uses a C6F14 liquid radiator and a 300 nm layer of CsI deposited on the cathode pad plane of an asymmetric MWPC. The RICH has operated for the Hypernuclear Spectroscopy Experiment E94-107, which took data in the last two years. Design details and performance along with first physics results from the hypernuclear experiment are shortly presented.

  2. Designing Technology Activities that Teach Mathematics

    ERIC Educational Resources Information Center

    Silk, Eli M.; Higashi, Ross; Shoop, Robin; Schunn, Christian D.

    2010-01-01

    Over the past three years, the authors have conducted research in middle and high school classrooms in an effort to improve the effectiveness of robotics to teach science, technology, engineering, and mathematics (STEM) education--their focus has been on math. The authors have found that subtle changes in the design and setup of the lesson make a…

  3. Design and Off-Design Performance of 100 kWe-Class Brayton Power Conversion Systems

    NASA Astrophysics Data System (ADS)

    Johnson, Paul K.; Mason, Lee S.

    2005-02-01

    The NASA Glenn Research Center in-house computer model Closed Cycle Engine Program (CCEP) was used to explore the design trade space and off-design performance characteristics of 100 kWe-class recuperated Closed Brayton Cycle (CBC) power conversion systems. Input variables for a potential design point included the number of operating units (1, 2, 4), cycle peak pressure (0.5, 1, 2 MPa), and turbo-alternator shaft speed (30,45, 60 kRPM). The design point analysis assumed a fixed turbine inlet temperature (1150 K), compressor inlet temperature (400 K), helium-xenon working-fluid molecular weight (40 g/mol), compressor pressure ratio (2.0), recuperator effectiveness (0.95), and a Sodium-Potassium (NaK) pumped-loop radiator. The design point options were compared on the basis of thermal input power, radiator area, and mass. For a nominal design point with defined Brayton components and radiator area, off-design cases were examined by reducing turbine inlet temperature (as low as 900 K), reducing shaft speed (as low as 50% of nominal), and circulating a percentage (up to 20%) of the compressor exit flow back to the gas cooler. The off-design examination sought approaches to reduce thermal input power without freezing the radiator.

  4. Design and Off-Design Performance of 100 kWe-Class Brayton Power Conversion Systems

    NASA Technical Reports Server (NTRS)

    Johnson, Paul K.; Mason, Lee S.

    2005-01-01

    The NASA Glenn Research Center in-house computer model Closed Cycle Engine Program (CCEP) was used to explore the design trade space and off-design performance characteristics of 100 kWe-class recuperated Closed Brayton Cycle (CBC) power conversion systems. Input variables for a potential design point included the number of operating units (1, 2, 4), cycle peak pressure (0.5, 1, 2 MPa), and turbo-alternator shaft speed (30, 45, 60 kRPM). The design point analysis assumed a fixed turbine inlet temperature (1150 K), compressor inlet temperature (400 K), helium-xenon working-fluid molecular weight (40 g/mol), compressor pressure ratio (2.0), recuperator effectiveness (0.95), and a Sodium-Potassium (NaK) pumped-loop radiator. The design point options were compared on the basis of thermal input power, radiator area, and mass. For a nominal design point with defined Brayton components and radiator area, off-design cases were examined by reducing turbine inlet temperature (as low as 900 K), reducing shaft speed (as low as 50 percent of nominal), and circulating a percentage (up to 20 percent) of the compressor exit flow back to the gas cooler. The off-design examination sought approaches to reduce thermal input power without freezing the radiator.

  5. Feed-pump hydraulic performance and design improvement, Phase I: research program design. Final report

    SciTech Connect

    Brown, W.H.; Gopalakrishnan, S.; Fehlau, R.; Thompson, W.E.; Wilson, D.G.

    1982-03-01

    As a result of prior EPRI-sponsored studies, it was concluded that a research program should be designed and implemented to provide an improved basis for the design, procurement, testing, and operation of large feed pumps with increased reliability and stability over the full range of operating conditions. This two-volume report contains a research plan which is based on a review of the present state of the art and which defines the necessary R and D program and estimates the benefits and costs of the program. The recommended research program consists of 30 interrelated tasks. It is designed to perform the needed research; to verify the results; to develop improved components; and to publish computer-aided design methods, pump specification guidelines, and a troubleshooting manual. Most of the technology proposed in the research plan is applicable to nuclear power plants as well as to fossil-fired plants. This volume discusses the design, performance and failures of feed pumps, and recommendations for research on pump dynamics, design, and specifications.

  6. The design, construction and performance of the MICE target

    NASA Astrophysics Data System (ADS)

    Booth, C. N.; Hodgson, P.; Howlett, L.; Nicholson, R.; Overton, E.; Robinson, M.; Smith, P. J.; Apollonio, M.; Barber, G.; Dobbs, A.; Leaver, J.; Long, K. R.; Shepherd, B.; Adams, D.; Capocci, E.; McCarron, E.; Tarrant, J.

    2013-03-01

    The pion-production target that serves the MICE Muon Beam consists of a titanium cylinder that is dipped into the halo of the ISIS proton beam. The design and construction of the MICE target system are described along with the quality-assurance procedures, electromagnetic drive and control systems, the readout electronics, and the data-acquisition system. The performance of the target is presented together with the particle rates delivered to the MICE Muon Beam. Finally, the beam loss in ISIS generated by the operation of the target is evaluated as a function of the particle rate, and the operating parameters of the target are derived.

  7. Design and Performance of Capping Layers for EUV Multilayer Mirrors

    SciTech Connect

    Bajt, S; Chapman, H N; Nuygen, N; Alameda, J; Robinson, J C; Malinowski, M; Gullikson, E; Aquila, A; Tarrio, C; Grantham, S

    2003-03-10

    The reflectance stability of multilayer coatings for extreme ultraviolet lithography (EUVL) in a commercial tool environment is of uttermost importance to ensure continuous exposures with minimum maintenance cost. We have made substantial progress in designing the protective capping layer coatings, understanding their performance and estimating their lifetimes based on accelerated electron beam and EUV exposure studies. Our current capping layer coatings have about 40 times longer lifetimes than Si-capped multilayer optics. Nevertheless, the lifetime of current Ru-capped multilayers is too short to satisfy commercial tool requirements and further improvements are essential.

  8. Design and performance of Skylab thermal/environmental control system

    NASA Technical Reports Server (NTRS)

    Hopson, G. D.; Littles, J. W.; Patterson, W. C.

    1974-01-01

    The function of the thermal/environmental control systems was to provide a comfortable thermal environment for the crew, to cool electronic components, to supply a controlled oxygen/nitrogen atmosphere, and to remove moisture, carbon dioxide, odors, and trace contaminants from the atmosphere. A separate refrigeration system was used to chill and freeze food and biomedical samples and to provide cold water for drinking. This paper describes system design and compares in-flight performance to preflight predictions. A discussion of in-flight anomalies and corrective actions is also included.

  9. Effect of design selection on response surface performance

    NASA Technical Reports Server (NTRS)

    Carpenter, William C.

    1993-01-01

    Artificial neural nets and polynomial approximations were used to develop response surfaces for several test problems. Based on the number of functional evaluations required to build the approximations and the number of undetermined parameters associated with the approximations, the performance of the two types of approximations was found to be comparable. A rule of thumb is developed for determining the number of nodes to be used on a hidden layer of an artificial neural net and the number of designs needed to train an approximation is discussed.

  10. Vane structure design trade-off and performance analysis

    NASA Astrophysics Data System (ADS)

    Breault, Robert P.

    1989-04-01

    The APART/PADE and ASAP stray-light software packages (Breault, 1988) are applied to the design of vane structures to block direct propagation paths from the surfaces of optical baffles to other system components. Results for several typical systems are presented in extensive tables and graphs and analyzed. It is shown that vane angle and depth are significant parameters only for the first-order propagation path. Also evaluated are the amounts of particulate debris produced by degraded vane coatings and the effects of the resulting surface contamination on system performance.

  11. A star-and-sky chopping polarimeter - Design and performance

    NASA Astrophysics Data System (ADS)

    Jain, S. K.; Srinivasulu, G.

    1991-09-01

    A star-and-sky chopping polarimeter is developed for accurate measurements of linear polarization of starlight in the standard astronomical photometric U, B, V, R, and I bands. The instrumental polarization, as determined by observing the standard unpolarized stars, is 0.04 percent. It is possible to use the instrument for the measurements of circular polarization as well. A Unicorn microcomputer controls the various operations of the instrument, acquires the data, and does the on-line data reduction. This paper describes the design and performance of the polarimeter.

  12. Design and Performance of the Vegetation Canopy Lidar (VCL) Laser Transmitter

    NASA Technical Reports Server (NTRS)

    Coyle, D. Barry; Kay, Richard B.; Lindauer, Steven J., II

    2002-01-01

    The Vegetation Canopy Lidar (VCL) laser is a Nd:YAG Q-switched, diode side-pumped, zig-zag slab design producing 10 ns, 15 mJ pulses at 1064 nm. It employs an unstable resonator as well as a graded reflectivity output coupler with a Gaussian reflectivity profile. In order to conserve power, a conductively cooled design is employed and is designed to operate over a range of 25 C without active thermal control. The laser is an oscillator-only design and equipped with an 15X beam expander to limit the output divergence to less than 60 microrad. Thermal lensing compensation in the side-pumped slab was performed with different treatments of the x and y portions of the z-directed beam. Performance data as a function of temperature are given.

  13. Control Design and Performance Analysis for Autonomous Formation Flight Experimentss

    NASA Astrophysics Data System (ADS)

    Rice, Caleb Michael

    Autonomous Formation Flight is a key approach for reducing greenhouse gas emissions and managing traffic in future high density airspace. Unmanned Aerial Vehicles (UAV's) have made it possible for the physical demonstration and validation of autonomous formation flight concepts inexpensively and eliminates the flight risk to human pilots. This thesis discusses the design, implementation, and flight testing of three different formation flight control methods, Proportional Integral and Derivative (PID); Fuzzy Logic (FL); and NonLinear Dynamic Inversion (NLDI), and their respective performance behavior. Experimental results show achievable autonomous formation flight and performance quality with a pair of low-cost unmanned research fixed wing aircraft and also with a solo vertical takeoff and landing (VTOL) quadrotor.

  14. Spiral microstrip hyperthermia applicators: technical design and clinical performance.

    PubMed

    Samulski, T V; Fessenden, P; Lee, E R; Kapp, D S; Tanabe, E; McEuen, A

    1990-01-01

    Spiral microstrip microwave (MW) antennas have been developed and adapted for use as clinical hyperthermia applicators. The design has been configured in a variety of forms including single fixed antenna applicators, multi-element arrays, and mechanically scanned single or paired antennas. The latter three configurations have been used to allow an expansion of the effective heating area. Specific absorption rate (SAR) distributions measured in phantom have been used to estimate the depth and volume of effective heating. The estimates are made using the bioheat equation assuming uniformly perfused tissue. In excess of 500 treatments of patients with advanced or recurrent localized superficial tumors have been performed using this applicator technology. Data from clinical treatments have been analyzed to quantify the heating performance and verify the suitability of these applicators for clinical use. Good microwave coupling efficiency together with the compact applicator size have proved to be valuable clinical assets.

  15. Resilient Plant Monitoring System: Design, Analysis, and Performance Evaluation

    SciTech Connect

    Humberto E. Garcia; Wen-Chiao Lin; Semyon M. Meerkov; Maruthi T. Ravichandran

    2013-12-01

    Resilient monitoring systems are sensor networks that degrade gracefully under malicious attacks on their sensors, causing them to project misleading information. The goal of this paper is to design, analyze, and evaluate the performance of a resilient monitoring system intended to monitor plant conditions (normal or anomalous). The architecture developed consists of four layers: data quality assessment, process variable assessment, plant condition assessment, and sensor network adaptation. Each of these layers is analyzed by either analytical or numerical tools, and the performance of the overall system is evaluated using simulations. The measure of resiliency of the resulting system is evaluated using Kullback Leibler divergence, and is shown to be sufficiently high in all scenarios considered.

  16. The Light Microscopy Module Design and Performance Demonstrations

    NASA Technical Reports Server (NTRS)

    Motil, Susan M.; Snead, John H.; Griffin, DeVon W.; Hovenac, Edward A.

    2003-01-01

    The Light Microscopy Module (LMM) is a state-of-the-art space station payload to provide investigations in the fields of fluids, condensed matter physics, and biological sciences. The LMM hardware will reside inside the Fluids Integrated Rack (FIR), a multi-user facility class payload that will provide fundamental services for the LMM and future payloads. LMM and FIR will be launched in 2005 and both will reside in the Destiny module of the International Space Station (ISS). There are five experiments to be performed within the LMM. This paper will provide a description of the initial five experiments: the supporting FIR subsystems; LMM design; capabilities and key features; and a summary of performance demonstrations.

  17. Attention in aviation. [to aircraft design and pilot performance

    NASA Technical Reports Server (NTRS)

    Wickens, Christopher D.

    1987-01-01

    The relevance of four principles or mechanisms of human attention to the design of aviation systems and the performance of pilots in multitask environments, including workload prediction and measurement, control-display integration, and the use of voice and head-up displays is discussed. The principles are: the mental energy that supplies task performance (resources), the resulting cross-talk between tasks as they are made more similar (confusion), the combination of different task elements (integration), and the way in which one task is processed and another is ignored (selection or tunneling). The introduction of greater levels of complexity into the validation of attentional theories in order to approach the demands of the cockpit or ATC console is proposed.

  18. Spiral microstrip hyperthermia applicators: technical design and clinical performance.

    PubMed

    Samulski, T V; Fessenden, P; Lee, E R; Kapp, D S; Tanabe, E; McEuen, A

    1990-01-01

    Spiral microstrip microwave (MW) antennas have been developed and adapted for use as clinical hyperthermia applicators. The design has been configured in a variety of forms including single fixed antenna applicators, multi-element arrays, and mechanically scanned single or paired antennas. The latter three configurations have been used to allow an expansion of the effective heating area. Specific absorption rate (SAR) distributions measured in phantom have been used to estimate the depth and volume of effective heating. The estimates are made using the bioheat equation assuming uniformly perfused tissue. In excess of 500 treatments of patients with advanced or recurrent localized superficial tumors have been performed using this applicator technology. Data from clinical treatments have been analyzed to quantify the heating performance and verify the suitability of these applicators for clinical use. Good microwave coupling efficiency together with the compact applicator size have proved to be valuable clinical assets. PMID:2298626

  19. Design and performance of a repeater for optical satellite communication

    NASA Astrophysics Data System (ADS)

    Ohm, G.; Wiesmann, Th.; Hieber, E.

    General design aspects of optical inter-satellite and inter-orbit links and the choice of technology for data relay applications are described. A first step toward optical links is the ESA in-orbit experiment SILEX which is briefly reviewed with emphasis on the communication subsystem. All relevant equipments of the communication subsystem, which is based on 0.85-micron laser diodes, QPPM data format, and direct detection, have been developed and tested. Using the equipment developed, an experimental repeater was assembled and investigated. Measured and simulated results are in close agreement, and no major critical events occurred during the development and test activities.

  20. The OmniTread serpentine robot: design and field performance

    NASA Astrophysics Data System (ADS)

    Borenstein, Johann; Granosik, Grzegorz; Hansen, Malik

    2005-05-01

    This paper describes the design and performance of the OmniTread serpentine robot, developed at the University of Michigan. Serpentine robots are mobile robots that comprise of multiple rigid segments, connected by actuated joints. The segments usually have drive elements, such as wheels or tracks. To date, we have developed two versions of the OmniTread. The larger version, called OT-8, has five rigid segments and four 2-Degree-of-Freedom (2-DOF) joints, and it can drive through an 8-inch diameter opening. The OT-8 is fully functional and this paper documents experimental results for the OT-8. The smaller and newer version, called "OT-4," will have seven segments, six 2- DOF joints, and it will fit through a 4 inch diameter hole. The OT-4 is not yet completely built, but its design is mostly completed and key improvements over the OT-8 have been bench tested. The foremost and unique design characteristic of the OmniTread is the use of pneumatic bellows to actuate the joints. The pneumatic bellows allow the simultaneous control of position and stiffness for each joint. Controllable stiffness is of crucial importance in serpentine robots, which require stiff joints to cross gaps and compliant joints to conform to rough terrain for effective propulsion. Another unique feature of the OmniTread design is the maximal coverage of all four sides of each segment with driven tracks. This design makes the robot indifferent to roll-overs, which are bound to happen when the long and slen-der bodies of serpentine robots travel over rugged terrain.

  1. Teacher Educators' Design and Implementation of Group Learning Activities

    ERIC Educational Resources Information Center

    De Hei, Miranda S. A.; Sjoer, Ellen; Admiraal, Wilfried; Strijbos, Jan-Willem

    2016-01-01

    The aim of this study was to describe how teacher educators design and implement group learning activities (GLAs). We used the Group Learning Activities Instructional Design (GLAID) framework to analyse their descriptions. The GLAID framework includes eight components: (1) interaction, (2) learning objectives and outcomes, (3) assessment, (4) task…

  2. Designing Inquiry-Oriented Science Lab Activities

    ERIC Educational Resources Information Center

    Longo, Christopher M.

    2011-01-01

    Mr. Smith and Ms. D'Amico are two veteran science teachers in a well-performing school district. Both teachers use weekly lab exercises and experiments as formative assessments. In their middle school classrooms, children are engaged and eager to learn. As students walk into Mr. Smith's classroom, a prescribed, step-by-step procedure of the day's…

  3. Structural Design and Sealing Performance Analysis of Biomimetic Sealing Ring.

    PubMed

    Han, Chuanjun; Zhang, Han; Zhang, Jie

    2015-01-01

    In order to reduce the failure probability of rubber sealing rings in reciprocating dynamic seal, a new structure of sealing ring based on bionics was designed. The biomimetic ring has three concave ridges and convex bulges on each side which are very similar to earthworms. Bulges were circularly designed and sealing performances of the biomimetic ring in both static seal and dynamic seal were simulated by FEM. In addition, effects of precompression, medium pressure, speed, friction coefficient, and material parameters on sealing performances were discussed. The results show that von Mises stress of the biomimetic sealing ring distributed symmetrically in no-pressure static sealing. The maximum von Mises stress appears on the second bulge of the inner side. High contact stress concentrates on left bulges. Von Mises stress distribution becomes uneven under medium pressure. Both von Mises stress and contact stress increase when precompression, medium pressure, and rubber hardness increase in static sealing. Biomimetic ring can avoid rolling and distortion in reciprocating dynamic seal, and its working life is much longer than O-ring and rectangular ring. The maximum von Mises stress and contact stress increase with the precompression, medium pressure, rubber hardness, and friction coefficient in reciprocating dynamic seal. PMID:27019582

  4. A conceptual design tool for RBCC engine performance analysis

    SciTech Connect

    Olds, J.R.; Saks, G.

    1997-01-01

    Future reusable launch vehicles will depend on new propulsion technologies to lower system operational costs while maintaining adequate performance. Recently, a number of vehicle systems utilizing rocket-based combined-cycle (RBCC) propulsion have been proposed as possible low-cost space launch solutions. Vehicles using RBCC propulsion have the potential to combine the best aspects of airbreathing propulsion (high average Isp) with the best aspects of rocket propulsion (high propellant bulk density and engine T/W). Proper conceptual assessment of each proposed vehicle will require computer-based tools that allow for quick and cheap, yet sufficiently accurate disciplinary analyses. At Georgia Tech, a spreadsheet-based tool has been developed that uses quasi-1D flow analysis with component efficiencies to parametrically model RBCC engine performance in ejector, fan-ramjet, ramjet and pure rocket modes. The technique is similar to an earlier RBCC modeling technique developed by the Marquardt Corporation in the mid-1960{close_quote}s. For a given sea-level static thrust requirement, the current tool generates engine weight and size data, as well as Isp and thrust data vs. altitude and Mach number. The latter is output in tabular form for use in a trajectory optimization program. This paper reviews the current state of the RBCC analysis tool and the effort to upgrade it from a Microsoft Excel spreadsheet to a design-oriented UNIX program in C suitable for integration into a multidisciplinary design optimization (MDO) framework. {copyright} {ital 1997 American Institute of Physics.}

  5. Design and implementation of a high performance network security processor

    NASA Astrophysics Data System (ADS)

    Wang, Haixin; Bai, Guoqiang; Chen, Hongyi

    2010-03-01

    The last few years have seen many significant progresses in the field of application-specific processors. One example is network security processors (NSPs) that perform various cryptographic operations specified by network security protocols and help to offload the computation intensive burdens from network processors (NPs). This article presents a high performance NSP system architecture implementation intended for both internet protocol security (IPSec) and secure socket layer (SSL) protocol acceleration, which are widely employed in virtual private network (VPN) and e-commerce applications. The efficient dual one-way pipelined data transfer skeleton and optimised integration scheme of the heterogenous parallel crypto engine arrays lead to a Gbps rate NSP, which is programmable with domain specific descriptor-based instructions. The descriptor-based control flow fragments large data packets and distributes them to the crypto engine arrays, which fully utilises the parallel computation resources and improves the overall system data throughput. A prototyping platform for this NSP design is implemented with a Xilinx XC3S5000 based FPGA chip set. Results show that the design gives a peak throughput for the IPSec ESP tunnel mode of 2.85 Gbps with over 2100 full SSL handshakes per second at a clock rate of 95 MHz.

  6. Structural Design and Sealing Performance Analysis of Biomimetic Sealing Ring.

    PubMed

    Han, Chuanjun; Zhang, Han; Zhang, Jie

    2015-01-01

    In order to reduce the failure probability of rubber sealing rings in reciprocating dynamic seal, a new structure of sealing ring based on bionics was designed. The biomimetic ring has three concave ridges and convex bulges on each side which are very similar to earthworms. Bulges were circularly designed and sealing performances of the biomimetic ring in both static seal and dynamic seal were simulated by FEM. In addition, effects of precompression, medium pressure, speed, friction coefficient, and material parameters on sealing performances were discussed. The results show that von Mises stress of the biomimetic sealing ring distributed symmetrically in no-pressure static sealing. The maximum von Mises stress appears on the second bulge of the inner side. High contact stress concentrates on left bulges. Von Mises stress distribution becomes uneven under medium pressure. Both von Mises stress and contact stress increase when precompression, medium pressure, and rubber hardness increase in static sealing. Biomimetic ring can avoid rolling and distortion in reciprocating dynamic seal, and its working life is much longer than O-ring and rectangular ring. The maximum von Mises stress and contact stress increase with the precompression, medium pressure, rubber hardness, and friction coefficient in reciprocating dynamic seal.

  7. Design and Performance of 40 cm Ion Optics

    NASA Technical Reports Server (NTRS)

    Soulas, George C.

    2001-01-01

    A 40 cm ion thruster is being developed at the NASA Glenn Research Center to obtain input power and propellant throughput capabilities of 10 kW and 550 kg. respectively. The technical approach here is a continuation of the "derating" technique used for the NSTAR ion thruster. The 40 cm ion thruster presently utilizes the NSTAR ion optics aperture geometry to take advantage of the large database of lifetime and performance data already available. Dome-shaped grids were chosen for the design of the 40 cm ion optics because this design is naturally suited for large-area ion optics. Ion extraction capabilities and electron backstreaming limits for the 40 cm ion optics were estimated by utilizing NSTAR 30 cm ion optics data. A preliminary service life assessment showed that the propellant throughput goal of 550 kg of xenon may be possible with molybdenum 40 cm ion optics. One 40 cm ion optics' set has been successfully fabricated to date. Additional ion optics' sets are presently being fabricated. Preliminary performance tests were conducted on a laboratory model 40 cm ion thruster.

  8. The design of linear algebra libraries for high performance computers

    SciTech Connect

    Dongarra, J.J. |; Walker, D.W.

    1993-08-01

    This paper discusses the design of linear algebra libraries for high performance computers. Particular emphasis is placed on the development of scalable algorithms for MIMD distributed memory concurrent computers. A brief description of the EISPACK, LINPACK, and LAPACK libraries is given, followed by an outline of ScaLAPACK, which is a distributed memory version of LAPACK currently under development. The importance of block-partitioned algorithms in reducing the frequency of data movement between different levels of hierarchical memory is stressed. The use of such algorithms helps reduce the message startup costs on distributed memory concurrent computers. Other key ideas in our approach are the use of distributed versions of the Level 3 Basic Linear Algebra Subprograms (BLAS) as computational building blocks, and the use of Basic Linear Algebra Communication Subprograms (BLACS) as communication building blocks. Together the distributed BLAS and the BLACS can be used to construct higher-level algorithms, and hide many details of the parallelism from the application developer. The block-cyclic data distribution is described, and adopted as a good way of distributing block-partitioned matrices. Block-partitioned versions of the Cholesky and LU factorizations are presented, and optimization issues associated with the implementation of the LU factorization algorithm on distributed memory concurrent computers are discussed, together with its performance on the Intel Delta system. Finally, approaches to the design of library interfaces are reviewed.

  9. Structural Design and Sealing Performance Analysis of Biomimetic Sealing Ring

    PubMed Central

    Han, Chuanjun

    2015-01-01

    In order to reduce the failure probability of rubber sealing rings in reciprocating dynamic seal, a new structure of sealing ring based on bionics was designed. The biomimetic ring has three concave ridges and convex bulges on each side which are very similar to earthworms. Bulges were circularly designed and sealing performances of the biomimetic ring in both static seal and dynamic seal were simulated by FEM. In addition, effects of precompression, medium pressure, speed, friction coefficient, and material parameters on sealing performances were discussed. The results show that von Mises stress of the biomimetic sealing ring distributed symmetrically in no-pressure static sealing. The maximum von Mises stress appears on the second bulge of the inner side. High contact stress concentrates on left bulges. Von Mises stress distribution becomes uneven under medium pressure. Both von Mises stress and contact stress increase when precompression, medium pressure, and rubber hardness increase in static sealing. Biomimetic ring can avoid rolling and distortion in reciprocating dynamic seal, and its working life is much longer than O-ring and rectangular ring. The maximum von Mises stress and contact stress increase with the precompression, medium pressure, rubber hardness, and friction coefficient in reciprocating dynamic seal. PMID:27019582

  10. Resistive wall mode active control physics design for KSTAR

    SciTech Connect

    Park, Y. S. Sabbagh, S. A.; Bialek, J. M.; Berkery, J. W.; Bak, J. G.; Lee, S. G.; Oh, Y. K.

    2014-01-15

    As KSTAR H-mode operation approaches the region where the resistive wall mode (RWM) can be unstable, an important issue for future long pulse, high beta plasma operation is to evaluate RWM active feedback control performance using a planned active/passive RWM stabilization system on the device. In particular, an optimal design of feedback sensors allows mode stabilization up to the highest achievable β{sub N} close to the ideal with-wall limit, β{sub N}{sup wall}, with reduced control power requirements. The computed ideal n = 1 mode structure from the DCON code has been input to the VALEN-3D code to calculate the projected performance of an active RWM control system in the KSTAR three-dimensional conducting structure device geometry. Control performance with the midplane locked mode detection sensors, off-midplane saddle loops, and magnetic pickup coils is examined. The midplane sensors measuring the radial component of the mode perturbation is found to be strongly affected by the wall eddy current. The off-axis saddle loops with proper compensation of the prompt applied field are computed to provide stabilization at β{sub N} up to 86% of β{sub N}{sup wall} but the low RWM amplitude computed in the off-axis regions near the sensors can produce a low signal-to-noise ratio. The required control power and bandwidth are also estimated with varied noise levels in the feedback sensors. Further improvements have been explored by examining a new RWM sensor design motivated by the off-midplane poloidal magnetic field sensors in NSTX. The new sensors mounted off of the copper passive stabilizer plates near the device midplane show a clear advantage in control performance corresponding to achieving 99% of β{sub N}{sup wall} without the need of compensation of the prompt field. The result shows a significant improvement of RWM feedback stabilization using the new sensor set which motivates a future feedback sensor upgrade.

  11. Design, fabrication and performance evaluation of a vaporizing liquid microthruster

    NASA Astrophysics Data System (ADS)

    Kundu, Pijus; Kanti Bhattacharyya, Tarun; Das, Soumen

    2012-02-01

    A recent application domain of MEMS technology is in the development of microthrusters for micro-/nanosatellites. Among the various types of MEMS microthruster developed so far, the vaporizing liquid microthruster (VLM) has been widely explored for its capability to produce continuously variable thrust in the micro-Newton (µN) to mili-Newton (mN) range. This paper reports the design and experimental validation of silicon MEMS VLM consisting of a microcavity, inlet channel and converging-diverging (C-D) in-plane exit nozzle integrated in two micromachined bonded chips and sandwiched between two p-diffused microheaters, located at the top and bottom surface of the device. Structural configuration was designed using simple analytical equations to achieve maximum thrust force by controlling the inlet propellant flow and heater power of VLM in an efficient way. In addition, a 3D model using a computational fluid dynamics technique was constructed to simulate the aft section of VLM for the investigation of its aerodynamic behavior. The device fabrication and testing have been briefly described. The fabricated VLM is capable to produce 1 mN thrust using maximum heater power of 3.6 W at a water flow rate of 2.04 mg s-1 using an in-plane C-D exit nozzle of throat area 130 µm × 100 µm. A detailed thrust force measurement was carried out with the variation of input heater power for different mass flow conditions and exit to throat area ratio of the exit nozzle, and the results were interpreted with the theoretical model. The model gives considerable physical insight in the operation of the VLM. Finally, a performance comparison with other published VLM results indicates that the present design can yield comparatively more thrust force with much less input power. A performance comparison with other published VLM results indicates that the present design can achieve improved performance by integrating two heaters with appropriate chamber volume in respect of propellant flow

  12. Feed-pump hydraulic performance and design improvement, Phase I: research program design. Final report

    SciTech Connect

    Brown, W.H.; Gopalakrishnan, S.; Fehlau, R.; Thompson, W.E.; Wilson, D.G.

    1982-03-01

    As a result of prior EPRI-sponsored studies, it was concluded that a research program should be designed and implemented to provide an improved basis for the design, procurement, testing, and operation of large feed pumps with increased reliability and stability over the full range of operating conditions. This two-volume report contains a research plan which is based on a review of the present state of the art and which defines the necessary R and D program and estimates the benefits and costs of the program. The recommended research program consists of 30 interrelated tasks. It is designed to perform the needed research; to verify the results; to develop improved components; and to publish computer-aided design methods, pump specification guidelines, and a troubleshooting manual. Most of the technology proposed in the research plan is applicable to nuclear power plants as well as to fossil-fired plants. This volume contains appendixes on pump design, cavitation damage, performance testing, hydraulics, two-phase flow in pumps, flow stability, and rotor dynamics.

  13. Design and performance of a cryogenic iris aperture mechanism

    NASA Astrophysics Data System (ADS)

    de Jonge, C.; Laauwen, W. M.; de Vries, E. A.; Smit, H. P.; Detrain, A.; Eggens, M. J.; Ferrari, L.; Dieleman, P.

    2014-07-01

    A cryogenic iris mechanism is under development as part of the ground calibration source for the SAFARI instrument. The iris mechanism is a variable aperture used as an optical shutter to fine-tune and modulate the absolute power output of the calibration source. It has 4 stainless steel blades that create a near-circular aperture in every position. The operating temperature is 4.5 Kelvin to provide a negligible background to the SAFARI detectors, and `hot spots' above 9K should be prevented. Cryogenic testing proved that the iris works at 4K. It can be used in a broad range of cryogenic optical instruments where optical throughput needs to be controlled. Challenges in the design include the low cooling power available (5mW) and low friction at cryogenic temperatures. The actuator is an `arc-type' rotary voice-coil motor. The use of flexural pivots creates a mono-stable mechanism with a resonance frequency at 26Hz. Accurate and fast position control with disturbance rejection is managed by a PID servo loop using a hall-sensor as input. At 4 Kelvin, the frequency is limited to 4Hz to avoid excess dissipation and heating. In this paper, the design and performance of the iris are discussed. The design was optimized using a thermal, magnetic and mechanical model made with COMSOL Finite Element Analysis software. The dynamical and state-space modeling of the mechanism and the concept of the electrical control are presented. The performance of the iris show good agreement to the analytical and COMSOL modeling.

  14. Design of anthropomorphic textured phantoms for CT performance evaluation

    NASA Astrophysics Data System (ADS)

    Solomon, Justin; Bochud, François; Samei, Ehsan

    2014-03-01

    Commercially available computed tomography (CT) technologies such as iterative reconstruction (IR) have the potential to enable reduced patient doses while maintaining diagnostic image quality. However, systematically determining safe dose reduction levels for IR algorithms is a challenging task due to their nonlinear nature. Most attempts to evaluate IR algorithms rely on measurements made in uniform phantoms. Such measurements may overstate the dose reduction potential of IR because they don't account for the complex relationship between anatomical variability and image quality. The purpose of this study was to design anatomically informed textured phantoms for CT performance evaluation. Two phantoms were designed to represent lung and soft-tissue textures. The lung phantom includes intricate vessel-like structures along with embedded nodules (spherical, lobulated, and spiculated). The soft tissue phantom was designed based on a three-dimensional clustered lumpy background with included low-contrast lesions (spherical and anthropomorphic). The phantoms were built using rapid prototyping (3D printing) technology and imaged on a modern multi-slice clinical CT scanner to assess the noise performance of a commercial IR algorithm in the context of uniform and textured backgrounds. Fifty repeated acquisitions were acquired for each background type and noise was assessed by measuring pixel standard deviation, across the ensemble of repeated acquisitions. For pixels in uniform areas, the IR algorithm reduced noise magnitude (STD) by 60% (compared to FBP). However, for edge pixels, the noise magnitude in the IR images ranged from 20% higher to 40% lower compared to FBP. In all FBP images and in IR images of the uniform phantom, noise appeared to be globally non-stationary (i.e., spatially dependent) but locally stationary (within a reasonably small region of interest). In the IR images of the textured phantoms, the noise was globally and locally non-stationary.

  15. Design and Preliminary Performance Testing of Electronegative Gas Plasma Thruster

    NASA Technical Reports Server (NTRS)

    Liu, Thomas M.; Schloeder, Natalie R.; Walker, Mitchell L. R.; Polzin, Kurt A.; Dankanich, John W.; Aanesland, Ane

    2014-01-01

    In classical gridded electrostatic ion thrusters, positively charged ions are generated from a plasma discharge of noble gas propellant and accelerated to provide thrust. To maintain overall charge balance on the propulsion system, a separate electron source is required to neutralize the ion beam as it exits the thruster. However, if high-electronegativity propellant gases (e.g., sulfur hexafluoride) are instead used, a plasma discharge can result consisting of both positively and negatively charged ions. Extracting such electronegative plasma species for thrust generation (e.g., with time-varying, bipolar ion optics) would eliminate the need for a separate neutralizer cathode subsystem. In addition for thrusters utilizing a RF plasma discharge, further simplification of the ion thruster power system may be possible by also using the RF power supply to bias the ion optics. Recently, the PEGASES (Plasma propulsion with Electronegative gases) thruster prototype successfully demonstrated proof-of-concept operations in alternatively accelerating positively and negatively charged ions from a RF discharge of a mixture of argon and sulfur hexafluoride.i In collaboration with NASA Marshall Space Flight Center (MSFC), the Georgia Institute of Technology High-Power Electric Propulsion Laboratory (HPEPL) is applying the lessons learned from PEGASES design and testing to develop a new thruster prototype. This prototype will incorporate design improvements and undergo gridless operational testing and diagnostics checkout at HPEPL in April 2014. Performance mapping with ion optics will be conducted at NASA MSFC starting in May 2014. The proposed paper discusses the design and preliminary performance testing of this electronegative gas plasma thruster prototype.

  16. Active noise control: A tutorial for HVAC designers

    SciTech Connect

    Gelin, L.J.

    1997-08-01

    This article will identify the capabilities and limitations of ANC in its application to HVAC noise control. ANC can be used in ducted HVAC systems to cancel ductborne, low-frequency fan noise by injecting sound waves of equal amplitude and opposite phase into an air duct, as close as possible to the source of the unwanted noise. Destructive interference of the fan noise and injected noise results in sound cancellation. The noise problems that it solves are typically described as rumble, roar or throb, all of which are difficult to address using traditional noise control methods. This article will also contrast the use of active against passive noise control techniques. The main differences between the two noise control measures are acoustic performance, energy consumption, and design flexibility. The article will first present the fundamentals and basic physics of ANC. The application to real HVAC systems will follow.

  17. Module Design, Materials, and Packaging Research Team: Activities and Capabilities

    SciTech Connect

    McMahon, T. J.; del Cueto, J.; Glick, S.; Jorgensen, G.; Kempe, M.; Kennedy, C.; Pern, J.; Terwilliger, K

    2005-01-01

    Our team activities are directed at improving PV module reliability by incorporating new, more effective, and less expensive packaging materials and techniques. New and existing materials or designs are evaluated before and during accelerated environmental exposure for the following properties: (1) Adhesion and cohesion: peel strength and lap shear. (2) Electrical conductivity: surface, bulk, interface and transients. (3) Water vapor transmission: solubility and diffusivity. (4) Accelerated weathering: ultraviolet, temperature, and damp heat tests. (5) Module and cell failure diagnostics: infrared imaging, individual cell shunt characterization, coring. (6) Fabrication improvements: SiOxNy barrier coatings and enhanced wet adhesion. (7) Numerical modeling: Moisture ingress/egress, module and cell performance, and cell-to-frame leakage current. (8) Rheological properties of polymer encapsulant and sheeting materials. Specific examples will be described.

  18. 42 CFR 460.136 - Internal quality assessment and performance improvement activities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... performance improvement activities. (1) A PACE organization must ensure that all interdisciplinary team... performance improvement requirements. A PACE organization must do the following: (1) Use a set of outcome... coordinator. A PACE organization must designate an individual to coordinate and oversee implementation...

  19. Design factors and performance efficiencies of successive alkalinity producing systems

    SciTech Connect

    Jage, C.R.; Zipper, C.E.

    1999-07-01

    Successive Alkalinity Producing Systems (SAPS) are passive treatment wetlands that have been used successfully in renovating acidic mine drainage (AMD) for several years. Unfortunately, design parameters and treatment efficiency of these systems vary widely due to a lack of clear, consistent design and construction guidelines. This study is investigating ten operating SAPS systems in Virginia and West Virginia for the purpose of identifying the relationship of design and construction factors to system performance. Influent and effluent water samples were collected for a period of two years or longer by the operators of each system. Each sample was analyzed for pH, alkalinity, acidity, sulfate, total iron, total manganese, and aluminum. The individual systems were also characterized according to system age, size, and construction materials. Residence times for the ten systems ranged from 4.5 hours to 13.31 days. On average, they were able to raise the pH 0.65 units and generate a net alkalinity of 84.84 mg/l as CaCO{sub 3}. Iron and manganese removal did occur in the SAPS cells, but the majority of the removal took place in post-SAPS settling ponds. Net alkalinity generation was positively correlated with residence time and iron removal rates suggesting a synergistic effect. Seasonal variation in alkalinity production was also noted, possibly indicating changes in alkalinity generation rates by dissimilatory sulfate reduction. These data provide the foundation for the development of a user-oriented SAPS design model based solely on influent AMD chemistry and final treatment goals as input parameters.

  20. Effects of Vigorous Intensity Physical Activity on Mathematics Test Performance

    ERIC Educational Resources Information Center

    Phillips, David S.; Hannon, James C.; Castelli, Darla M.

    2015-01-01

    The effect of an acute bout of physical activity on academic performance in school-based settings is under researched. The purpose of this study was to examine associations between a single, vigorous (70-85%) bout of physical activity completed during physical education on standardized mathematics test performance among 72, eighth grade students…

  1. Materials Design for Joinable, High Performance Aluminum Alloys

    NASA Astrophysics Data System (ADS)

    Glamm, Ryan James

    An aluminum alloy compatible with friction stir welding is designed for automotive and aerospace structural applications. Current weldable automotive aluminum alloys do not possess the necessary strength to meet safety standards and therefore are not able to replace steel in the automotive body. Significant weight savings could be achieved if steel components are replaced with aluminum. Current aerospace alloys are not weldable, requiring machining of large pieces that are then riveted together. If an aerospace alloy could be friction stir welded, smaller pieces could be welded, reducing material waste. Using a systems approach for materials design, property goals are set from performance objectives. From previous research and computational predictions, a structure is designed for a prototype alloy containing dynamic precipitates to readily dissolve and re-precipitate and high stability precipitates to resist dissolution and coarsening in the weld region. It is found that a Ag modified Al-3.9Mg-0.04Cu (at. %) alloy enhanced the rate and magnitude of hardening during ageing, both beneficial effects for dynamic precipitation. In the same alloy, ageing at 350°C results in hardening from Al 3(Sc,Zr) precipitates. Efforts to effectively precipitate both populations simultaneously are unsuccessful. The Al3(Sc,Zr) precipitation hardened prototype is friction stir processed and no weak zones are found in the weld hardness profile. An aerospace alloy design is proposed, utilizing the dual precipitate structure shown in the prototype. The automotive alloy is designed using a basic strength model with parameters determined from the initial prototype alloy analysis. After ageing to different conditions, the alloy is put through a simulated heat affected zone thermal cycle with a computer controlled induction heater. The aged samples lose hardness from the weld cycle but recover hardness from a post weld heat treatment. Atom probe tomography and transmission electron

  2. Geoscience Laser Ranging System design and performance predictions

    NASA Technical Reports Server (NTRS)

    Anderson, Kent L.

    1991-01-01

    The Geoscience Laser System (GLRS) will be a high-precision distance-measuring instrument planned for deployment on the EOS-B platform. Its primary objectives are to perform ranging measurements to ground targets to monitor crustal deformation and tectonic plate motions, and nadir-looking altimetry to determine ice sheet thicknesses, surface topography, and vertical profiles of clouds and aerosols. The system uses a mode-locked, 3-color Nd:YAG laser source, a Microchannel Plate-PMT for absolute time-of-flight (TOF) measurement (at 532 nm), a streak camera for TOF 2-color dispersion measurement (532 nm and 355 nm), and a Si avalanche photodiode for altimeter waveform detection (1064 nm). The performance goals are to make ranging measurements to ground targets with about 1 cm accuracy, and altimetry height measurements over ice with 10 cm accuracy. This paper presents an overview of the design concept developed during a phase B study. System engineering issues and trade studies are discussed, with particular attention to error budgets and performance predictions.

  3. Terahertz quantum-well photodetectors: Design, performance, and improvements

    SciTech Connect

    Zhang, S. Wang, T. M.; Hao, M. R.; Yang, Y.; Zhang, Y. H.; Shen, W. Z.; Liu, H. C.

    2013-11-21

    Theoretical studies and numerical simulations on design, performance, and improvements of terahertz quantum-well photodetector (THz QWP) are presented. In the first part of this paper, we discuss the device band structure resulting from a self-consistent solution and simulation results. First, the temperature dependence of device characteristics is analyzed. Next, we deduce the condition of optimal doping concentration for maximizing dark current limited detectivity D{sub det}* when QWP is lightly doped. Accordingly, unlike in previously published reports, doping concentration is not fixed and is selected by the above condition. In the second part of this paper, we propose two schemes for improving operation temperature. The first is to incorporate an optical antenna which focuses incident THz wave. Numerical results show that the QWP with peak frequency higher than 5.5 THz is expected to achieve background-noise-limited performance at 77 K or above when employing a 10{sup 6} times enhancement antenna. The second scheme is to use a laser as the signal source to achieve photon-noise-limited performance (PLIP) at high temperatures. Simulations show that when operating below critical temperature QWPs in the range of 1 ∼ 7 THz can reach PLIP under practical illumination intensities.

  4. Centrifugal and Axial Pump Design and Off-Design Performance Prediction

    NASA Technical Reports Server (NTRS)

    Veres, Joseph P.

    1995-01-01

    A meanline pump-flow modeling method has been developed to provide a fast capability for modeling pumps of cryogenic rocket engines. Based on this method, a meanline pump-flow code PUMPA was written that can predict the performance of pumps at off-design operating conditions, given the loss of the diffusion system at the design point. The design-point rotor efficiency and slip factors are obtained from empirical correlations to rotor-specific speed and geometry. The pump code can model axial, inducer, mixed-flow, and centrifugal pumps and can model multistage pumps in series. The rapid input setup and computer run time for this meanline pump flow code make it an effective analysis and conceptual design tool. The map-generation capabilities of the code provide the information needed for interfacing with a rocket engine system modeling code. The off-design and multistage modeling capabilities of PUMPA permit the user to do parametric design space exploration of candidate pump configurations and to provide head-flow maps for engine system evaluation.

  5. Design for learning: deconstructing virtual patient activities.

    PubMed

    Ellaway, Rachel H; Davies, David

    2011-01-01

    Digital technologies are used in almost every aspect of contemporary health professional education (HPE) but our understanding of their true potential as instructional tools rather than administrative tools has not significantly advanced in the last decade. One notable exception to this has been the rise of the 'virtual patient' as an educational intervention in HPE. This article attempts to deconstruct the virtual patient concept by developing a model of virtual patients as artifacts with intrinsic encoded properties and emergent constructed properties that build on the core concept of 'activity'.

  6. Advanced Microstructured Semiconductor Neutron Detectors: Design, Fabrication, and Performance

    NASA Astrophysics Data System (ADS)

    Bellinger, Steven Lawrence

    The microstructured semiconductor neutron detector (MSND) was investigated and previous designs were improved and optimized. In the present work, fabrication techniques have been refined and improved to produce three-dimensional microstructured semiconductor neutron detectors with reduced leakage current, reduced capacitance, highly anisotropic deep etched trenches, and increased signal-to-noise ratios. As a result of these improvements, new MSND detection systems function with better gamma-ray discrimination and are easier to fabricate than previous designs. In addition to the microstructured diode fabrication improvement, a superior batch processing backfill-method for 6LiF neutron reactive material, resulting in a nearly-solid backfill, was developed. This method incorporates a LiF nano-sizing process and a centrifugal batch process for backfilling the nanoparticle LiF material. To better transition the MSND detector to commercialization, the fabrication process was studied and enhanced to better facilitate low cost and batch process MSND production. The research and development of the MSND technology described in this work includes fabrication of variant microstructured diode designs, which have been simulated through MSND physics models to predict performance and neutron detection efficiency, and testing the operational performance of these designs in regards to neutron detection efficiency, gamma-ray rejection, and silicon fabrication methodology. The highest thermal-neutron detection efficiency reported to date for a solid-state semiconductor detector is presented in this work. MSNDs show excellent neutron to gamma-ray (n/γ) rejection ratios, which are on the order of 106, without significant loss in thermal-neutron detection efficiency. Individually, the MSND is intrinsically highly sensitive to thermal neutrons, but not extrinsically sensitive because of their small size. To improve upon this, individual MSNDs were tiled together into a 6x6-element array

  7. Toward a mathematical formalism of performance, task difficulty, and activation

    NASA Technical Reports Server (NTRS)

    Samaras, George M.

    1988-01-01

    The rudiments of a mathematical formalism for handling operational, physiological, and psychological concepts are developed for use by the man-machine system design engineer. The formalism provides a framework for developing a structured, systematic approach to the interface design problem, using existing mathematical tools, and simplifying the problem of telling a machine how to measure and use performance.

  8. Estimating Basic Preliminary Design Performances of Aerospace Vehicles

    NASA Technical Reports Server (NTRS)

    Luz, Paul L.; Alexander, Reginald

    2004-01-01

    Aerodynamics and Performance Estimation Toolset is a collection of four software programs for rapidly estimating the preliminary design performance of aerospace vehicles represented by doing simplified calculations based on ballistic trajectories, the ideal rocket equation, and supersonic wedges through standard atmosphere. The program consists of a set of Microsoft Excel worksheet subprograms. The input and output data are presented in a user-friendly format, and calculations are performed rapidly enough that the user can iterate among different trajectories and/or shapes to perform "what-if" studies. Estimates that can be computed by these programs include: 1. Ballistic trajectories as a function of departure angles, initial velocities, initial positions, and target altitudes; assuming point masses and no atmosphere. The program plots the trajectory in two-dimensions and outputs the position, pitch, and velocity along the trajectory. 2. The "Rocket Equation" program calculates and plots the trade space for a vehicle s propellant mass fraction over a range of specific impulse and mission velocity values, propellant mass fractions as functions of specific impulses and velocities. 3. "Standard Atmosphere" will estimate the temperature, speed of sound, pressure, and air density as a function of altitude in a standard atmosphere, properties of a standard atmosphere as functions of altitude. 4. "Supersonic Wedges" will calculate the free-stream, normal-shock, oblique-shock, and isentropic flow properties for a wedge-shaped body flying supersonically through a standard atmosphere. It will also calculate the maximum angle for which a shock remains attached, and the minimum Mach number for which a shock becomes attached, all as functions of the wedge angle, altitude, and Mach number.

  9. Oxygen rich gas generator design and performance analysis

    NASA Technical Reports Server (NTRS)

    Gloyer, P. W.; Knuth, W. H.; Crawford, R. A.

    1993-01-01

    The present oxygen-rich combustion research investigates oxygen gas generator concepts. The theoretical and modeling aspects of a selected concept are presented, together with a refined concept resulting from the findings of the study. This investigation examined a counter-flow gas generator design for O2/H2 mass ratios of 100-200, featuring a near-stoichiometric combustion zone followed by downstream mixing. The critical technologies required to develop a performance model are analyzed and include the following: (1) oxygen flow boiling; (2) two-phase oxygen flow heat transfer; (3) film-cooling in the combustion zone; (4) oxygen-rich combustion with hydrogen; and (5) mixing and dilution.

  10. Design and Performance of the Keck Angle Tracker

    NASA Technical Reports Server (NTRS)

    Crawford, Samuel L.; Ragland, S.; Booth, A.; Colavita, M. M.; Hovland, E.

    2006-01-01

    The Keck Angle Tracker (KAT) is a key subsystem in the NASA-funded Keck Interferometer at the Keck Observatory on the summit of Mauna Kea in Hawaii. KAT, which has been in operation since the achievement of first fringes in March 2001, senses the tilt of the stellar wavefront for each of the beams from the interferometer telescopes and provides tilt error signals to fast tip/tilt mirrors for high-bandwidth, wavefront tilt correction. In addition, KAT passes low-bandwidth, desaturation offsets to the adaptive optics system of the Keck telescopes to correct for slow pointing drifts. We present an overview of the instrument design and recent performance of KAT in support of the V2 science and nulling observing modes of the Keck Interferometer.

  11. Moon Age and Regolith Explorer (MARE) Mission Design and Performance

    NASA Technical Reports Server (NTRS)

    Condon, Gerald L.; Lee, David E.

    2016-01-01

    The moon’s surface last saw a controlled landing from a U.S. spacecraft on December 11, 1972 with Apollo 17. Since that time, there has been an absence of methodical in-situ investigation of the lunar surface. In addition to the scientific value of measuring the age and composition of a relatively young portion of the lunar surface near Aristarchus Plateau, the Moon Age and Regolith Explorer (MARE) proposal provides the first U.S. soft lunar landing since the Apollo Program and the first ever robotic soft lunar landing employing an autonomous hazard detection and avoidance system, a system that promises to enhance crew safety and survivability during a manned lunar (or other) landing. This report focuses on the mission design and performance associated with the MARE robotic lunar landing subject to mission and trajectory constraints.

  12. The Advanced Photon Source (APS) Linear Accelerator: design and performance

    SciTech Connect

    White, M.M.

    1996-06-01

    The Advanced Photon Source linear accelerator (linac) system consists of a 200-MeV, 2856-MHz S-band electron linac and a 2-radiation-length- thick tungsten target followed by a 450-MeV positron linac. The linac system has operated 24 hours per day for the past two years to support accelerator commissioning and beam studies, and to provide beam for the experimental program. It achieves the design goal for positron current of 8 mA, and produces electron energies up to 650 MeV without the target in place. The linac is described, and its operation and performance are discussed. 9 refs., 3 figs., 1 tab.

  13. The design and performance of the Gravity Probe B telescope

    NASA Astrophysics Data System (ADS)

    Wang, Suwen; Lipa, J. A.; Gwo, D.-H.; Triebes, K.; Turneaure, J. P.; Farley, R. P.; Davidson, D.; Bower, K. A.; Acworth, E. B.; Bernier, R. J.; Huff, L. W.; Schweiger, P. F.; Goebel, J. H.

    2015-11-01

    The Gravity Probe B spacecraft was launched on 20 April 2004 to measure the geodetic and frame-dragging effects predicted by the theory of general relativity. A cryogenic optical telescope was used to establish the inertial reference frame for the measurements by tracking a reference or guide star. The motion of this star was independently checked by reference to background galaxies. With the mission now over, we describe the design, construction and evaluation of the optical and electrical performance of the telescope, comparing ground and flight results. We find that the pointing noise was sufficiently low to meet the mission requirements and in fair agreement with extrapolations from ground tests. Due to slight defocusing, the linear range of the telescope output was significantly wider than expected.

  14. Design features and performance of a high speed TDMA demodulator

    NASA Astrophysics Data System (ADS)

    Wallace, R. L.

    Design features and performance ranges of a new TDMA demodulator are presented. The device includes 500 MHz bandwidth amplifier stages with 15 dB gain, a bandpass filter for band rejection and receiver noise filtering, a pin attenuator, and a diode limiter to minimize the driving force variations and prevent saturation and overload effects. The demodulator is capable of burst-to-burst I.F. leveling, optimal coherent carrier recovery, and symbol clock recovery in 1.5 microsec. Less than 1 dB modem loss in data demodulation is achieved, compared with theoretical values, using Nyquist, matched filtering techniques at the baseband. Finally, the device has a time sampled, digitized COSTAS recovered carrier phasing loop and operates at a data rate of 48 Mbps.

  15. Advanced Wet Tantalum Capacitors: Design, Specifications and Performance

    NASA Technical Reports Server (NTRS)

    Teverovsky, Alexander

    2016-01-01

    Insertion of new types of commercial, high volumetric efficiency wet tantalum capacitors in space systems requires reassessment of the existing quality assurance approaches that have been developed for capacitors manufactured to MIL-PRF-39006 requirements. The specifics of wet electrolytic capacitors is that leakage currents flowing through electrolyte can cause gas generation resulting in building up of internal gas pressure and rupture of the case. The risk associated with excessive leakage currents and increased pressure is greater for high value advanced wet tantalum capacitors, but it has not been properly evaluated yet. This presentation gives a review of specifics of the design, performance, and potential reliability risks associated with advanced wet tantalum capacitors. Problems related to setting adequate requirements for DPA, leakage currents, hermeticity, stability at low and high temperatures, ripple currents for parts operating in vacuum, and random vibration testing are discussed. Recommendations for screening and qualification to reduce risks of failures have been suggested.

  16. Design and performance of a positron-sensitive surgical probe

    NASA Astrophysics Data System (ADS)

    Liu, Fang

    We report the design and performance of a portable positron-sensitive surgical imaging probe. The probe is designed to be sensitive to positrons and capable of rejecting background gammas including 511 keV. The probe consists of a multi-anode PMT and an 8 x 8 array of thin 2 mm x 2 mm plastic scintillators coupled 1:1 to GSO crystals. The probe uses three selection criteria to identify positrons. An energy threshold on the plastic signals reduces the false positron signals in the plastic due to background gammas; a second energy threshold on the PMT sum signal greatly reduces background gammas in the GSO. Finally, a timing window accepts only 511 keV gammas from the GSO that arrive within 15 ns of the plastic signals, reducing accidental coincidences to a negligible level. The first application being investigated is sentinel lymph node (SLN) surgery, to identify in real-time the location of SLNs in the axilla with high 18F-FDG uptake, which may indicate metastasis. Our simulations and measurements show that the probe's pixel separation ability in terms of peak-to-valley ratio is ˜3.5. The performance measurements also show that the 64-pixel probe has a sensitivity of 4.7 kcps/muCi using optimal signal selection criteria. For example, it is able to detect in 10 seconds a ˜4 mm lesion with a true-to-background ratio of ˜3 at a tumor uptake ratio of ˜8:1. The signal selection criteria can be fine-tuned, either for higher sensitivity, or for a higher image contrast.

  17. Design and performance of the beamlet optical switch

    SciTech Connect

    Rhodes, M.A.; Woods, B.W.; DeYoreo, J.J.

    1996-06-01

    High-energy lasers for Inertial Confinement Fusion (ICF) experiments are typically designed with large apertures (>30 cm) to keep the fluence below the damage threshold of the various optical components. Until recently, no optical switch technology could be scaled to the aperture size, aperture shape (square), and switching speed required for the next generation of ICF drivers. This step is critical: The Beamlet multipass amplifier cavity uses a full-aperture optical switch to trap the laser pulse within the cavity and to divert the pulse out of the cavity when it reaches the required energy. By rotating the polarization of the beam, a Pockels cell in the switch controls whether the beam is transmitted through, or reflected from, the polarizer. In this article the authors describe an optical switch technology that does scale to the required aperture size and shape for Beamlet and the porposed National Ignition Facility (NIF) laser, and can employ a thin crystal. This switch consists of a thin-film polarizer and a plasma-electrode Pockels cell (PEPC), the latter originally invented at Lawrence Livermore National Laboratory (LLNL) in the 1980s and under further development since 1991. After discussing the PEPC concept, they present the design and optical performance of a 32 x 32 cm{sup 2} prototype PEPC, including discussions of the crystals, the PEPC assembly, the vacuum and gas system, and the high-voltage pulsers. Then they describe the performance of the 37 x 37 cm{sup 2} PEPC construced specifically for the Beamlet laser. Finally, they discuss important technology issues that arose during PEPC development: cathode sputtering, cathode heating, nonuniformities in the switching profile, switch-pulse leakage current, and an estimate of the plasma density and temperature produced during PEPC operation.

  18. Computational Human Performance Modeling For Alarm System Design

    SciTech Connect

    Jacques Hugo

    2012-07-01

    The introduction of new technologies like adaptive automation systems and advanced alarms processing and presentation techniques in nuclear power plants is already having an impact on the safety and effectiveness of plant operations and also the role of the control room operator. This impact is expected to escalate dramatically as more and more nuclear power utilities embark on upgrade projects in order to extend the lifetime of their plants. One of the most visible impacts in control rooms will be the need to replace aging alarm systems. Because most of these alarm systems use obsolete technologies, the methods, techniques and tools that were used to design the previous generation of alarm system designs are no longer effective and need to be updated. The same applies to the need to analyze and redefine operators’ alarm handling tasks. In the past, methods for analyzing human tasks and workload have relied on crude, paper-based methods that often lacked traceability. New approaches are needed to allow analysts to model and represent the new concepts of alarm operation and human-system interaction. State-of-the-art task simulation tools are now available that offer a cost-effective and efficient method for examining the effect of operator performance in different conditions and operational scenarios. A discrete event simulation system was used by human factors researchers at the Idaho National Laboratory to develop a generic alarm handling model to examine the effect of operator performance with simulated modern alarm system. It allowed analysts to evaluate alarm generation patterns as well as critical task times and human workload predicted by the system.

  19. Design and Performance Considerations for the Quantitative Measurement of HEU Residues Resulting from 99Mo Production

    SciTech Connect

    McElroy, Robert Dennis; Chapman, Jeffrey Allen; Bogard, James S; Belian, Anthony P

    2011-01-01

    Molybdenum-99 is produced by the irradiation of high-enriched uranium (HEU) resulting in the accumulation of large quantities of HEU residues. In general, these residues are not recycled but are either disposed of or stored in containers with surface exposure rates as high as 100 R/h. The 235U content of these waste containers must be quantified for both accountability and waste disposal purposes. The challenges of quantifying such difficult-to-assay materials are discussed, along with performance estimates for each of several potential assay options. In particular, the design and performance of a High Activity Active Well Coincidence Counting (HA-AWCC) system designed and built specifically for these irradiated HEU waste materials are presented.

  20. Design and Flight Performance of NOAA-K Spacecraft Batteries

    NASA Technical Reports Server (NTRS)

    Rao, Gopalakrishna M.; Chetty, P. R. K.; Spitzer, Tom; Chilelli, P.

    1998-01-01

    The US National Oceanic and Atmospheric Administration (NOAA) operates the Polar Operational Environmental Satellite (POES) spacecraft (among others) to support weather forecasting, severe storm tracking, and meteorological research by the National Weather Service (NWS). The latest in the POES series of spacecraft, named as NOAA-KLMNN', one is in orbit and four more are in various phases of development. The NOAA-K spacecraft was launched on May 13, 1998. Each of these spacecraft carry three Nickel-Cadmium batteries designed and manufactured by Lockheed Martin. The battery, which consists of seventeen 40 Ah cells manufactured by SAFT, provides the spacecraft power during the ascent phase, orbital eclipse and when the power demand is in excess of the solar array capability. The NOAA-K satellite is in a 98 degree inclination, 7:30AM ascending node orbit. In this orbit the satellite experiences earth occultation only 25% of the year. This paper provides a brief overview of the power subsystem, followed by the battery design and qualification, the cell life cycle test data, and the performance during launch and in orbit.

  1. Design and Flight Performance of NOAA-K Spacecraft Batteries

    NASA Technical Reports Server (NTRS)

    Rao, Gopalakrishna M.; Chetty, P. R. K.; Spitzer, Tom; Chilelli, P.

    1999-01-01

    The US National Oceanic and Atmospheric Administration (NOAA) operates the Polar Operational Environmental Satellite (POES) spacecraft (among others) to support weather forecasting, severe storm tracking, and meteorological research by the National Weather Service (NWS). The latest in the POES series of spacecraft, named as NOAA-KLMNN, is in orbit and four more are in various phases of development. The NOAA-K spacecraft was launched on May 13, 1998. Each of these spacecraft carry three Nickel-Cadmium batteries designed and manufactured by Lockheed Martin. The battery, which consists of seventeen 40 Ah cells manufactured by SAFT, provides the spacecraft power during the ascent phase, orbital eclipse and when the power demand is in excess of the solar array capability. The NOAA-K satellite is in a 98 degree inclination, 7:30AM ascending node orbit. In this orbit the satellite experiences earth occultation only 25% of the year. This paper provides a brief overview of the power subsystem, followed by the battery design and qualification, the cell life cycle test data, and the performance during launch and in orbit.

  2. Design and performance of the HVE electrostatic nuclear microprobe

    NASA Astrophysics Data System (ADS)

    Podaru, Nicolae C.; van de Hoef, F. L.; Gottdang, A.; Mous, D. J. W.

    2013-07-01

    High Voltage Engineering (HVE) designed, built and tested its first electrostatic nuclear microprobe lens with micrometer lateral resolution, based on the “Russian” quadruplet configuration. Ray tracing and three dimensional finite element methods were applied to quantify the role of spherical and parasitic aberrations, to optimize the lens geometry (e.g. electrode to bore diameter ratio) and to determine allowable mechanical tolerances. The lateral resolution of the nuclear microprobe was measured using a 1.5 MeV He+ ion beam. An image of 6.8 (±0.2) μm × 6.1 (±0.2) μm (FWHM) was obtained for an object size of 100 (±1) μm × 100 (±1) μm with 0.23 mrad half-angle divergence (33% lens filling). This closely corresponds to the expected beam size based on the calculated theoretical demagnification of 16.08 (15.5 measured). Additionally, this indicates the little contribution of the spherical and parasitical aberrations and a good agreement between design and actual performance.

  3. ACS sampling system: design, implementation, and performance evaluation

    NASA Astrophysics Data System (ADS)

    Di Marcantonio, Paolo; Cirami, Roberto; Chiozzi, Gianluca

    2004-09-01

    By means of ACS (ALMA Common Software) framework we designed and implemented a sampling system which allows sampling of every Characteristic Component Property with a specific, user-defined, sustained frequency limited only by the hardware. Collected data are sent to various clients (one or more Java plotting widgets, a dedicated GUI or a COTS application) using the ACS/CORBA Notification Channel. The data transport is optimized: samples are cached locally and sent in packets with a lower and user-defined frequency to keep network load under control. Simultaneous sampling of the Properties of different Components is also possible. Together with the design and implementation issues we present the performance of the sampling system evaluated on two different platforms: on a VME based system using VxWorks RTOS (currently adopted by ALMA) and on a PC/104+ embedded platform using Red Hat 9 Linux operating system. The PC/104+ solution offers, as an alternative, a low cost PC compatible hardware environment with free and open operating system.

  4. Performance criteria for the optical designs for VISTA

    NASA Astrophysics Data System (ADS)

    Worswick, Susan P.; Atad-Ettedgui, Eli; Casali, Mark M.; Henry, David M.

    2000-07-01

    The Visible and Infra-red Survey Telescope for Astronomy, or VISTA, is a UK funded four meter class wide-field, infrared and optical survey telescope to be situated in Chile. The telescope, which can be regarded as a two-channel camera, provides a one-degree, infrared field and a two-degree, optical field. The project goal of low running cost requires minimal intervention by support staff. The optical configuration of the telescope must meet the scientific requirements while delivering a stable instrument profile for the 12-year duration of the survey. Accurate calibration of throughput, image quality and field distortion will be essential to the photometric and astrometric quality of that survey. The process for selection of optical design options is described and discussed with particular reference to meeting the functional and performance requirements, determined from the scientific specification, and to achieving a predictable and reliable image quality. The practical limitations imposed by budgetary and operational requirements are assessed for their role as contributory design drivers.

  5. Software Design Document for the AMP Nuclear Fuel Performance Code

    SciTech Connect

    Philip, Bobby; Clarno, Kevin T; Cochran, Bill

    2010-03-01

    The purpose of this document is to describe the design of the AMP nuclear fuel performance code. It provides an overview of the decomposition into separable components, an overview of what those components will do, and the strategic basis for the design. The primary components of a computational physics code include a user interface, physics packages, material properties, mathematics solvers, and computational infrastructure. Some capability from established off-the-shelf (OTS) packages will be leveraged in the development of AMP, but the primary physics components will be entirely new. The material properties required by these physics operators include many highly non-linear properties, which will be replicated from FRAPCON and LIFE where applicable, as well as some computationally-intensive operations, such as gap conductance, which depends upon the plenum pressure. Because there is extensive capability in off-the-shelf leadership class computational solvers, AMP will leverage the Trilinos, PETSc, and SUNDIALS packages. The computational infrastructure includes a build system, mesh database, and other building blocks of a computational physics package. The user interface will be developed through a collaborative effort with the Nuclear Energy Advanced Modeling and Simulation (NEAMS) Capability Transfer program element as much as possible and will be discussed in detail in a future document.

  6. Effect of Operating Conditions and Design on Afterburner Performance

    NASA Technical Reports Server (NTRS)

    Fleming, W. A.; Gabriel, D. S.; Lundin, B. T.

    1956-01-01

    Afterburners for turbojet engines have, within the past decade, found increasing application in service aircraft. Practically all engines manufactured today are equipped with some form of afterburner, and its use has increased from what was originally a short-period thrust-augmentation application to an essential feature of the turbojet propulsion system for flight at supersonic speeds. The design of these afterburners has been based on extensive research and development effort in expanded laboratory facilities by both the NACA and the American engine industry. Most of the work of the engine industry, however, has either not been published or is not generally available owing to its proprietary nature. Consequently, the main bulk of research information available for summary and discussion is of NACA origin. However, because industrial afterburner development has closely followed NACA research, the omission is more one of technical detail than method or concept. One principal difficulty encountered in summarizing the work in this field is that sufficient knowledge does not yet exist to rationally or directly integrate the available background of basic combustion principles into combustor design. A further difficulty is that most of the experimental investigations that have been conducted were directed chiefly toward the development of specific afterburners for various engines rather than to the accumulation of systematic data. This work has, nonetheless, provided not only substantial improvements in the performance of afterburners but also a large fund of experimental data and an extensive background of experience in the field. Consequently, it is the purpose of the present chapter to summarize the many, and frequently unrelated, experimental investigations that have been conducted rather than to formulate a set of design rules. In the treatment of this material an effort has been made, however, to convey to the reader the "know how" acquired by research engineers

  7. Active-region designs in quantum cascade lasers

    SciTech Connect

    Zasavitskii, I I

    2012-10-31

    This paper analyses the development of active-region designs in quantum cascade lasers. Active-region designs have been demonstrated to date that employ various radiative transitions (vertical, diagonal, interminiband and interband). The lower laser level is depopulated through nonradiative transitions, such as one- or two-phonon (and even three-phonon) relaxation or bound state {yields} continuum transitions. Advances in active-region designs and energy diagram optimisation in the past few years have led to significant improvements in important characteristics of quantum cascade lasers, such as their output power, emission bandwidth, characteristic temperature and efficiency. (invited paper)

  8. Orbit design and optimization based on global telecommunication performance metrics

    NASA Technical Reports Server (NTRS)

    Lee, Seungwon; Lee, Charles H.; Kerridge, Stuart; Cheung, Kar-Ming; Edwards, Charles D.

    2006-01-01

    The orbit selection of telecommunications orbiters is one of the critical design processes and should be guided by global telecom performance metrics and mission-specific constraints. In order to aid the orbit selection, we have coupled the Telecom Orbit Analysis and Simulation Tool (TOAST) with genetic optimization algorithms. As a demonstration, we have applied the developed tool to select an optimal orbit for general Mars telecommunications orbiters with the constraint of being a frozen orbit. While a typical optimization goal is to minimize tele-communications down time, several relevant performance metrics are examined: 1) area-weighted average gap time, 2) global maximum of local maximum gap time, 3) global maximum of local minimum gap time. Optimal solutions are found with each of the metrics. Common and different features among the optimal solutions as well as the advantage and disadvantage of each metric are presented. The optimal solutions are compared with several candidate orbits that were considered during the development of Mars Telecommunications Orbiter.

  9. Magnetohydrodynamic Augmented Propulsion Experiment: I. Performance Analysis and Design

    NASA Technical Reports Server (NTRS)

    Litchford, R. J.; Cole, J. W.; Lineberry, J. T.; Chapman, J. N.; Schmidt, H. J.; Lineberry, C. W.

    2003-01-01

    The performance of conventional thermal propulsion systems is fundamentally constrained by the specific energy limitations associated with chemical fuels and the thermal limits of available materials. Electromagnetic thrust augmentation represents one intriguing possibility for improving the fuel composition of thermal propulsion systems, thereby increasing overall specific energy characteristics; however, realization of such a system requires an extremely high-energy-density electrical power source as well as an efficient plasma acceleration device. This Technical Publication describes the development of an experimental research facility for investigating the use of cross-field magnetohydrodynamic (MHD) accelerators as a possible thrust augmentation device for thermal propulsion systems. In this experiment,a 1.5-MW(sub e) Aerotherm arc heater is used to drive a 2-MW(sub e) MHD accelerator. The heatsink MHD accelerator is configured as an externally diagonalized, segmented channel, which is inserted into a large-bore, 2-T electromagnet. The performance analysis and engineering design of the flow path are described as well as the parameter measurements and flow diagnostics planned for the initial series of test runs.

  10. Fundamental SAR ATR performance predictions for design trade-offs

    NASA Astrophysics Data System (ADS)

    Horowitz, Larry L.; Brendel, Gary F.

    1997-07-01

    This paper discusses work toward a fundamental, algorithm- independent view of the ATR performance that can be achieved using SAR data. Such ATR performance predictions are intended to enable evaluation of performance tradeoffs for SAR designs, including both parameter selections and added domains of SAR observation, such as 3D, full polarimetry, multiaspect and/or multifrequency. In the paper we evaluate the classification error for two tactical targets using a Monte Carlo technique. A number of approximations are made and are detailed in the paper. Data on target signatures come from pencil-beam laser data and target photographs, which determine shadowing of the ground clutter. A single aspect angle is used for each target in the initial results. A layer of radar netting is modeled on both targets. This information is used as 'ground truth', to compute the average power that would be seen in each pixel of a SAR image, for each target. SAR image trials are then generated using independent Rayleigh amplitude fades in each pixel. In an optimal Bayesian fashion, the smaller of the probabilities of target (T1) or T2 given the trial image data is the error probability for that trial. An average over the Monte Carlo image trials yields the overall classification error probability. Comments are given on reducing the number of required trials in such a Monte Carlo. THree results of the work are shown. First, a tradeoff is made of ATR performance versus SAR resolution. ATR improves as the resolution is made finer, and physical reasons for this are discussed. Second, the relative ATR utility is determined for those pixels where at least one target has scatterer as compared with those pixels where the targets differ only in the degree to which they shadow the ground clutter. Third, an early analytical result is given for interferometric SAR, showing the physical reason behind the potential of height-sensing SAR to improve ATR - the possibility of canceling the background

  11. GPM Avionics Module Heat Pipes Design and Performance Test Results

    NASA Technical Reports Server (NTRS)

    Ottenstein, Laura; DeChristopher, Mike

    2011-01-01

    The Global Precipitation Measurement (GPM) mission is an international network of satellites that provide the next-generation global observations of rain and snow. The GPM core satellite carries an advanced radar / radiometer system to measure precipitation from space and serve as a reference standard to unify precipitation measurements from a constellation of research and operational satellites. Through improved measurements of precipitation globally, the GPM mission will help to advance our understanding of Earth's water and energy cycle, improve forecasting of extreme events that cause natural hazards and disasters, and extend current capabilities in using accurate and timely information of precipitation to directly benefit society. The avionics module on the core satellite contains a number of electronics boxes which are cooled by a network of aluminum/ammonia heat pipes and a honeycomb radiator which contains thirteen embedded aluminum/ammonia heat pipes. All heat pipes were individually tested by the vendor (Advanced Cooling Technologies, Inc.) prior to delivery. Following delivery to NASA, the flight avionics radiator and the flight spare transport heat pipes were mounted to flight-like test structure and a system level thermal vacuum test was performed. This test, which used simulators in place of all electronics boxes, was done to verify the operation of the thermal control system as a whole. This presentation will discuss the design of the avionics module heat pipes, and then discuss performance tests results for the individual heat pipes prior to delivery and for the system level thermal vacuum test. All heat pipes met their performance requirements. However, it was found that the power was too low in some instances to start all of the smaller radiator spreader heat pipes when they were tested in a reflux configuration (which is the nominal test configuration). Although this lowered the efficiency of the radiator somewhat, it did not impact the operating

  12. Enhanced terahertz imaging system performance analysis and design tool for concealed weapon identification

    NASA Astrophysics Data System (ADS)

    Murrill, Steven R.; Franck, Charmaine C.; Espinola, Richard L.; Petkie, Douglas T.; De Lucia, Frank C.; Jacobs, Eddie L.

    2011-11-01

    The U.S. Army Research Laboratory (ARL) and the U.S. Army Night Vision and Electronic Sensors Directorate (NVESD) have developed a terahertz-band imaging system performance model/tool for detection and identification of concealed weaponry. The details of the MATLAB-based model which accounts for the effects of all critical sensor and display components, and for the effects of atmospheric attenuation, concealment material attenuation, and active illumination, were reported on at the 2005 SPIE Europe Security & Defence Symposium (Brugge). An advanced version of the base model that accounts for both the dramatic impact that target and background orientation can have on target observability as related to specular and Lambertian reflections captured by an active-illumination-based imaging system, and for the impact of target and background thermal emission, was reported on at the 2007 SPIE Defense and Security Symposium (Orlando). This paper will provide a comprehensive review of an enhanced, user-friendly, Windows-executable, terahertz-band imaging system performance analysis and design tool that now includes additional features such as a MODTRAN-based atmospheric attenuation calculator and advanced system architecture configuration inputs that allow for straightforward performance analysis of active or passive systems based on scanning (single- or line-array detector element(s)) or staring (focal-plane-array detector elements) imaging architectures. This newly enhanced THz imaging system design tool is an extension of the advanced THz imaging system performance model that was developed under the Defense Advanced Research Project Agency's (DARPA) Terahertz Imaging Focal-Plane Technology (TIFT) program. This paper will also provide example system component (active-illumination source and detector) trade-study analyses using the new features of this user-friendly THz imaging system performance analysis and design tool.

  13. Quasi-active suspension design using magnetorheological dampers

    NASA Astrophysics Data System (ADS)

    Potter, Jack N.; Neild, Simon A.; Wagg, David J.

    2011-05-01

    Quasi-active damping is a method of coupled mechanical and control system design using multiple semi-active dampers. By designing the systems such that the desired control force may always be achieved using a combination of the dampers, quasi-active damping seeks to approach levels of vibration isolation achievable through active damping, whilst retaining the desirable attributes of semi-active systems. In this article a design is proposed for a quasi-active, base-isolating suspension system. Control laws are firstly defined in a generalised form, where semi-active dampers are considered as idealised variable viscous dampers. This system is used to demonstrate in detail the principles of quasi-active damping, in particular the necessary interaction between mechanical and control systems. It is shown how such a system can produce a tunable, quasi-active region in the frequency response of very low displacement transmissibility. Quasi-active control laws are then proposed which are specific for use with magnetorheological dampers. These are validated in simulation using a realistic model of the damper dynamics, again producing a quasi-active region in the frequency response. Finally, the robustness of the magnetorheological, quasi-active suspension system is demonstrated.

  14. Position paper - peer review and design verification of selected activities

    SciTech Connect

    Stine, M.D.

    1994-09-01

    Position Paper to develop and document a position on the performance of independent peer reviews on selected design and analysis components of the Title I (preliminary) and Title II (detailed) design phases of the Multi-Function Waste Tank Facility project.

  15. High School Student Information Access and Engineering Design Performance

    ERIC Educational Resources Information Center

    Mentzer, Nathan

    2014-01-01

    Developing solutions to engineering design problems requires access to information. Research has shown that appropriately accessing and using information in the design process improves solution quality. This quasi-experimental study provides two groups of high school students with a design problem in a three hour design experience. One group has…

  16. Practical Design Activities for Your Technology Education Classes

    ERIC Educational Resources Information Center

    Berkeihiser, Mike

    2006-01-01

    In this article, the author relates how he and his class get involved in doing project designs within their school district every year. The author relates how they have done design projects for local townships and boroughs, non-profit organizations, Eagle Scout projects, and much more. The author relates how these activities have been such…

  17. Cryogenic engineering for OMEGA2000: design and performance

    NASA Astrophysics Data System (ADS)

    Baumeister, Harald; Bizenberger, Peter; Bayler-Jones, Coryn A. L.; Kovács, Zoltan; Röser, Hermann-Josef; Rohloff, Ralf-Rainer

    2003-03-01

    Omega2000 is a prime focus near infrared (NIR) wide-field camera for the 3.5 meter telescope at Calar Alto/Spain. Having a large field of view and an excellent optical quality, the instrument is particularly designed for survey observations. A cryogenic four lens focal reducer delivers a 15.4 x 15.4 arcminute field of view (FOV) with a pixel scale of 0.45"/pixel. The lenses are made of various optical materials, including CaF2 and BaF2 with diameters of up to 150 mm. They must be specially mounted to survive cooling and to follow the tight tolerances (+/- 0.05 mm for lens centricity and +/- 30 arcsec for lens tilt) required by the optical design. For a wide range of observing applications, a filter mechanism can hold up to 17 filters of 3 inch diameter in 3 filter wheels. For exact and reproducible filter positions, a mechanical locking mechanism has been developed which also improves the cool-down performance of the filter wheels and filters. This mechanism allows a minimum distance of about 3 mm between the filter wheels. A Rockwell HAWAII-2 FPA is used to cover the wavelength range from 0.85 μm to 2.4 μm. Special care has been taken with regard to the thermal coupling of the detector. The thermal connection is made by gold layers on the fanout board and an additional spring-loaded mechanism. A warm mirror baffle system has been developed, in order to minimize the thermal background for K band observations. The camera is a focal reducer only and has no cold pupil stop.

  18. Design and early performance of IGRINS (Immersion Grating Infrared Spectrometer)

    NASA Astrophysics Data System (ADS)

    Park, Chan; Jaffe, Daniel T.; Yuk, In-Soo; Chun, Moo-Young; Pak, Soojong; Kim, Kang-Min; Pavel, Michael; Lee, Hanshin; Oh, Heeyoung; Jeong, Ueejeong; Sim, Chae Kyung; Lee, Hye-In; Nguyen Le, Huynh Anh; Strubhar, Joseph; Gully-Santiago, Michael; Oh, Jae Sok; Cha, Sang-Mok; Moon, Bongkon; Park, Kwijong; Brooks, Cynthia; Ko, Kyeongyeon; Han, Jeong-Yeol; Nah, Jakyoung; Hill, Peter C.; Lee, Sungho; Barnes, Stuart; Yu, Young Sam; Kaplan, Kyle; Mace, Gregory; Kim, Hwihyun; Lee, Jae-Joon; Hwang, Narae; Park, Byeong-Gon

    2014-07-01

    The Immersion Grating Infrared Spectrometer (IGRINS) is a compact high-resolution near-infrared cross-dispersed spectrograph whose primary disperser is a silicon immersion grating. IGRINS covers the entire portion of the wavelength range between 1.45 and 2.45μm that is accessible from the ground and does so in a single exposure with a resolving power of 40,000. Individual volume phase holographic (VPH) gratings serve as cross-dispersing elements for separate spectrograph arms covering the H and K bands. On the 2.7m Harlan J. Smith telescope at the McDonald Observatory, the slit size is 1ʺ x 15ʺ and the plate scale is 0.27ʺ pixel. The spectrograph employs two 2048 x 2048 pixel Teledyne Scientific and Imaging HAWAII-2RG detectors with SIDECAR ASIC cryogenic controllers. The instrument includes four subsystems; a calibration unit, an input relay optics module, a slit-viewing camera, and nearly identical H and K spectrograph modules. The use of a silicon immersion grating and a compact white pupil design allows the spectrograph collimated beam size to be only 25mm, which permits a moderately sized (0.96m x 0.6m x 0.38m) rectangular cryostat to contain the entire spectrograph. The fabrication and assembly of the optical and mechanical components were completed in 2013. We describe the major design characteristics of the instrument including the system requirements and the technical strategy to meet them. We also present early performance test results obtained from the commissioning runs at the McDonald Observatory.

  19. Bedroom design and decoration: gender differences in preference and activity.

    PubMed

    Jones, Randall M; Taylor, Denise E; Dick, Andrew J; Singh, Archana; Cook, Jerry L

    2007-01-01

    This investigation examined gender differences in niche-building preference and activity among 238 8th and 9th grade boys and girls. A questionnaire was developed to measure both the actual and preferred bedroom content, bedroom design activity, and the level of perceived influence by the immediate and extended family, friends, and social institutions. Gender differences were identified for preference, activity, and influence in bedroom design and decoration. Girls and boys differed in the type of items contained in their bedrooms. Girls' rooms contained stuffed animals and pictures of people, including themselves, more frequently than the boys' rooms. In contrast, boys' rooms contained sports-related items, and things for building or that they had built themselves. Although bedroom design activity for both boys and girls was influenced by older teens, friends, media, and popular culture, boys (but not girls) were also influenced by their mothers, fathers, girlfriends, and activities such as sports, Boy or Girl Scouts, and music lessons.

  20. Bedroom design and decoration: gender differences in preference and activity.

    PubMed

    Jones, Randall M; Taylor, Denise E; Dick, Andrew J; Singh, Archana; Cook, Jerry L

    2007-01-01

    This investigation examined gender differences in niche-building preference and activity among 238 8th and 9th grade boys and girls. A questionnaire was developed to measure both the actual and preferred bedroom content, bedroom design activity, and the level of perceived influence by the immediate and extended family, friends, and social institutions. Gender differences were identified for preference, activity, and influence in bedroom design and decoration. Girls and boys differed in the type of items contained in their bedrooms. Girls' rooms contained stuffed animals and pictures of people, including themselves, more frequently than the boys' rooms. In contrast, boys' rooms contained sports-related items, and things for building or that they had built themselves. Although bedroom design activity for both boys and girls was influenced by older teens, friends, media, and popular culture, boys (but not girls) were also influenced by their mothers, fathers, girlfriends, and activities such as sports, Boy or Girl Scouts, and music lessons. PMID:18047237

  1. The Light Microscopy Module Design and Performance Demonstrations

    NASA Astrophysics Data System (ADS)

    Motil, S. M.; Snead, J. H.; Griffin, D. W.; Hovenac, E. A.

    2002-01-01

    The Light Microscopy Module (LMM) is planned as a remotely controllable, automated, on-orbit microscope subrack facility, allowing flexible scheduling and control of fluids and biology experiments within the Fluids and Combustion Facility (FCF) Fluids Integrated Rack (FIR) on the International Space Station (ISS). The LMM recently completed the preliminary design phase, and is progressing toward engineering model development. This paper will provide a description of the LMM preliminary design, LMM planned capabilities and key features, a summary of demonstrations for each of the diagnostics, and future plans. In addition, a brief description of the initial four experiments will be provided. Key diagnostic capabilities for meeting science requirements include video microscopy to observe microscopic phenonema and dynamic interactions, interferometry to make thin film measurements with nanometer resolution, laser tweezers for particle manipulation, confocal microscopy to provide enhanced three-dimensional visualization of structures, and spectrophotometry to measure photonic properties of materials. The LMM also provides experiment sample containment for frangibles and fluids. Sample cell design allows investigators to perform experiments and observations on a variety of sample materials, including potential biological specimens. The LMM features high resolution video microscopy, brightfield, darkfield, phase contrast, differential interference contrast (DIC), and spectrophotometry in the visible 400 nm to 700 nm range. Laser tweezers is a custom-built system, shown to be capable of trapping up to a 5x5 array of colloidal particles. The LMM confocal system includes a commercial-off-the-shelf unit which utilizes a 532 nm frequency doubled Nd:Yag laser. This instrument has been demonstrated to provide images up to 80 microns deep in collodial samples. Spectrophotometry is a custom-built system that utilizes existing optical components within the microscope in addition

  2. Time to pay attention: attentional performance time-stamped prefrontal cholinergic activation, diurnality and performance

    PubMed Central

    Paolone, Giovanna; Lee, Theresa M.; Sarter, Martin

    2012-01-01

    Although the impairments in cognitive performance that result from shifting or disrupting daily rhythms have been demonstrated, the neuronal mechanisms that optimize fixed time daily performance are poorly understood. We previously demonstrated that daily practice of a sustained attention task (SAT) evokes a diurnal activity pattern in rats. Here we report that SAT practice at a fixed time produced practice time-stamped increases in prefrontal cholinergic neurotransmission that persisted after SAT practice was terminated and in a different environment. SAT time-stamped cholinergic activation occurred irrespective of whether the SAT was practiced during the light or dark phase or in constant light conditions. In contrast, prior daily practice of an operant schedule of reinforcement, albeit generating more rewards and lever presses per session than the SAT, neither activated the cholinergic system nor affected the animals' nocturnal activity pattern. Likewise, food-restricted animals exhibited strong food anticipatory activity (FAA) and attenuated activity during the dark period but FAA was not associated with increases in prefrontal cholinergic activity. Removal of cholinergic neurons impaired SAT performance and facilitated the reemergence of nocturnality. Shifting SAT practice away from a fixed time resulted in significantly lower performance. In conclusion, these experiments demonstrated that fixed time, daily practice of a task assessing attention generates a precisely practice time-stamped activation of the cortical cholinergic input system. Time-stamped cholinergic activation benefits fixed time performance and, if practiced during the light phase, contributes to a diurnal activity pattern. PMID:22933795

  3. Design requirements document for Project W-465, immobilized low-activity waste interim storage

    SciTech Connect

    Burbank, D.A.

    1998-05-19

    The scope of this Design Requirements Document (DRD) is to identify the functions and associated requirements that must be performed to accept, transport, handle, and store immobilized low-activity waste (ILAW) produced by the privatized Tank Waste Remediation System (TWRS) treatment contractors. The functional and performance requirements in this document provide the basis for the conceptual design of the TWRS ILAW Interim Storage facility project and provides traceability from the program level requirements to the project design activity. Technical and programmatic risk associated with the TWRS planning basis are discussed in the Tank Waste Remediation System Decisions and Risk Assessment (Johnson 1994). The design requirements provided in this document will be augmented by additional detailed design data documented by the project.

  4. Francium sources at Laboratori Nazionali di Legnaro: Design and performance

    SciTech Connect

    Stancari, G.; Veronesi, S.; Corradi, L.; Atutov, S.N.; Calabrese, R.; Dainelli, A.; Mariotti, E.; Moi, L.; Sanguinetti, S.; Tomassetti, L.

    2006-03-15

    A facility for the production of radioactive francium is operating at the laboratories of the Istituto Nazionale di Fisica Nucleare (INFN) in Legnaro, Italy. The goal is to collect a cold sample of radioactive atoms in a magneto-optical trap for studies in atomic, nuclear, and particle physics. Production of francium is achieved via the fusion-evaporation reaction {sup 197}Au({sup 18}O,kn){sup 215-k}Fr generated by a {approx}100-MeV {sup 18}O{sup 6+} beam on a thick gold target. The production target is heated to {approx}1200 K and kept at a potential of +3 kV to enhance Fr diffusion and surface desorption. Average production rates are 0.7x10{sup 6} ions/s for {sup 210}Fr with a primary beam flux of 10{sup 12} particles/s, with peaks of 2x10{sup 6} ions/s. Details are given on the design and construction of the production targets and on the measurements that characterize their performance.

  5. Francium sources at Laboratori Nazionali di Legnaro: Design and performance

    NASA Astrophysics Data System (ADS)

    Stancari, G.; Veronesi, S.; Corradi, L.; Atutov, S. N.; Calabrese, R.; Dainelli, A.; Mariotti, E.; Moi, L.; Sanguinetti, S.; Tomassetti, L.

    2006-03-01

    A facility for the production of radioactive francium is operating at the laboratories of the Istituto Nazionale di Fisica Nucleare (INFN) in Legnaro, Italy. The goal is to collect a cold sample of radioactive atoms in a magneto-optical trap for studies in atomic, nuclear, and particle physics. Production of francium is achieved via the fusion-evaporation reaction Au197(O18,kn)215-kFr generated by a ˜100-MeV O6+18 beam on a thick gold target. The production target is heated to ˜1200K and kept at a potential of +3kV to enhance Fr diffusion and surface desorption. Average production rates are 0.7×106ions/s for Fr210 with a primary beam flux of 1012particles/s, with peaks of 2×106ions/s. Details are given on the design and construction of the production targets and on the measurements that characterize their performance.

  6. Design consideration and performance analysis of OCT-based topography

    NASA Astrophysics Data System (ADS)

    Meemon, Panomsak; Yao, Jianing; Rolland, Jannick P.

    2014-03-01

    We report a study on design consideration and performance analysis of OCT-based topography by tracking of maximum intensity at each layer's interface. We demonstrate that, for a given stabilized OCT system, a high precision and accuracy of OCT-based layers and thickness topography in the order of tens nanometer can be achieved by using a technique of maximum amplitude tracking. The submicron precision was obtained by over sampling through the FFT of the acquired spectral fringes but was eventually limited by the system stability. Furthermore, we report characterization of a precision, repeatability, and accuracy of the surfaces, sub-surfaces, and thickness topography using our optimized FD-OCT system. We verified that for a given stability of our OCT system, precision of the detected position of signal's peak of down to 20 nm was obtained. In addition, we quantified the degradation of the precision caused by sensitivity fall-off over depth of FD-OCT. The measured precision is about 20 nm at about 0.1 mm depth, and degrades to about 80 nm at 1 mm depth, a position of about 10 dB sensitivity fall-off. The measured repeatability of thickness measurements over depth was approximately 0.04 micron. Finally, the accuracy of the system was verified by comparing with a digital micrometer gauging.

  7. Design and performance of low-wattage electrical heater probe

    SciTech Connect

    Biddle, R.; Wetzel, J.R.; Cech, R.

    1997-11-01

    A mound electrical calibration heater (MECH) has been used in several EG and G Mound developed calorimeters as a calibration tool. They are very useful over the wattage range of a few to 500 W. At the lower end of the range, a bias develops between the MECH probe and calibrated heat standards. A low-wattage electrical calibration heater (L WECH) probe is being developed by the Safeguards Science and Technology group (NIS-5) of Los Alamos National Laboratory based upon a concept proposed by EG and G Mound personnel. The probe combines electrical resistive heating and laser-light powered heating. The LWECH probe is being developed for use with power settings up to 2W. The electrical heater will be used at the high end of the range, and laser-light power will be used low end of the wattage range. The system consists of two components: the heater probe and a control unit. The probe is inserted into the measuring cavity through an opening in the insulating baffle, and a sleeve is required to adapt to the measuring chamber. The probe is powered and controlled using electronics modules located separately. This paper will report on the design of the LWECH probe, initial tests, and expected performance.

  8. Space Station Cathode Design, Performance, and Operating Specifications

    NASA Technical Reports Server (NTRS)

    Patterson, Michael J.; Verhey, Timothy R.; Soulas, George; Zakany, James

    1998-01-01

    A plasma contactor system was baselined for the International Space Station (ISS) to eliminate/mitigate damaging interactions with the space environment. The system represents a dual-use technology which is a direct outgrowth of the NASA electric propulsion program and, in particular, the technology development efforts on ion thruster systems. The plasma contactor includes a hollow cathode assembly (HCA), a power electronics unit, and a xenon gas feed system. Under a pre-flight development program, these subsystems were taken to the level of maturity appropriate for transfer to U.S. industry for final development. NASA's Lewis Research Center was subsequently requested by ISS to manufacture and deliver the engineering model, qualification model, and flight HCA units. To date, multiple units have been built. One cathode has demonstrated approximately 28,000 hours lifetime, two development unit HCAs have demonstrated over 10,000 hours lifetime, and one development unit HCA has demonstrated more than 32,000 ignitions. All 8 flight HCAs have been manufactured, acceptance tested, and are ready for delivery to the flight contractor. This paper discusses the requirements, mechanical design, performance, operating specifications, and schedule for the plasma contactor flight HCAs.

  9. System design and performances of ASTER Level-1 data processing

    NASA Astrophysics Data System (ADS)

    Nishida, Sumiyuki; Hachiya, Jun; Matsumoto, Ken; Fujisada, Hiroyuki; Kato, Masatane

    1998-12-01

    ASTER is a multispectral imager which covers wide spectral region from visible to thermal infrared with 14 spectral bands, and will fly on EOS-AM1 in 1999. To meet this wide spectral coverage, ASTER has three optical sensing subsystems (multi-telescope system), VNIR, SWIR and TIR. This multi- telescope configuration requires highly refined ground processing for the generation of Level-1 data products that are radiometrically calibrated and geometrically corrected. A prototype Level-1 processing software system is developed to satisfy these requirements. System design concept adopted includes; (1) 'Automatic Processing,' (2)'ALL-IN-ONE-CONCEPT' in which the processing is carried out using information included in Level-0 data product only, (3) 'MODULE INDEPENDENCE' in which only process control module independently control other modules to change any operational conditions. (4) 'FLEXIBILITY' in which important operation parameters are set from an external component to make the processing condition change easier. The adaptability and the performance of the developed software system are evaluated using simulation data.

  10. Design and performance of the LANL 158-channel magnetoencephalography system

    SciTech Connect

    Matlachov, A. N.; Kraus, Robert H., Jr.; Espy, M. A.; Best, E. D.; Briles, M. Carolyn; Raby, E. Y.; Flynn, E. R.

    2002-01-01

    Design and performance for a recently completed whole-head magnetoencephalography (MEG) system using a superconducting imaging-surface (SIS) surrounding an array of SQUID magnetometers is reported. The helmet-like SIS is hemispherical in shape with a brim. The SIS images nearby sources while shields sensors from ambient magnetic noise. The shielding factor depends on magnetometer position and orientation. Typical shielding values of 200 in central sulcus area have been observed. Nine reference channels form three vector magnetometers, which are placed outside SIS. Signal channels consist of 149 SQUID magnetometers with 0.84nT/{Phi}{sub 0} field sensitivity and less then 3 fT/{radical}Hz noise. Typical SQUID - room temperature separations are about 20mm in the cooled state. Twelve 16-channel flux-lock loop units are connected to two 96-channel control units allowing up to 192 total SQUID channels. The control unit includes signal conditioning circuits as well as system test and control circuits. After conditioning all signals are fed to 192-channel, 24-bit data acquisition system capable of sampling up to 48kSa/sec/channel. The SIS-MEG system enables high-quality human functional brain data to be recorded in a one-layer magnetically shielded room.

  11. Design and performance of a multiterawatt, subpicosecond neodymium glass laser

    SciTech Connect

    Patterson, F.G.; Perry, M.D.

    1990-09-01

    Broad-band solid-state materials such as Nd:Glass, Ti:Sapphire and Alexandrite, exhibit saturation fluences on the order of Joules/cm{sup 2}. Unfortunately, the large stored energy density of these solid state materials cannot be accessed directly with short pulses due to beam filamentation caused by the intensity dependent refractive index. This limits the power density in a solid state amplifier to only a few GW/cm{sup 2}. The application of chirped- pulsed amplification (CPA) to solid-state lasers circumvents this problem. With the CPA technique, a chirped, comparatively long pulse is produced and compressed to a short pulse only after amplification. The intensity in the amplifiers is kept below the level for significant nonlinear phase distortion. In this paper, we present the design and performance of a small scale Nd:Glass laser system employing chirped-pulse amplification to produce subpicosecond pulses exhibiting peak power exceeding 10 TW. 30 refs., 2 figs.

  12. Performance Evaluation of the Gravity Probe B Design

    NASA Technical Reports Server (NTRS)

    Francis, Ronnie; Wells, Eugene M.

    1996-01-01

    This report documents the simulation of the Lockheed Martin designed Gravity Probe B (GPB) spacecraft developed tool by bd Systems Inc using the TREETOPS simulation. This study quantifies the effects of flexibility and liquid helium slosh on GPB spacecraft control performance. The TREETOPS simulation tool permits the simulation of flexible structures given that a flexible body model of the structure is available. For purposes of this study, a flexible model of the GPB spacecraft was obtained from Lockheed Martin. To model the liquid helium slosh effects, computational fluid dynamics (CFD) results' were obtained, and used to develop a dynamic model of the slosh effects. The flexible body and slosh effects were incorporated separately into the TREETOPS simulation, which places the vehicle in a 650 km circular polar orbit and subjects the spacecraft to realistic environmental disturbances and sensor error quantities. In all of the analysis conducted in this study the spacecraft is pointed at an inertially fixed guide star (GS) and is rotating at a constant rate about this line of sight.

  13. Effect of design selection on response surface performance

    NASA Technical Reports Server (NTRS)

    Carpenter, William C.

    1993-01-01

    The mathematical formulation of the engineering optimization problem is given. Evaluation of the objective function and constraint equations can be very expensive in a computational sense. Thus, it is desirable to use as few evaluations as possible in obtaining its solution. In solving the equation, one approach is to develop approximations to the objective function and/or restraint equations and then to solve the equation using the approximations in place of the original functions. These approximations are referred to as response surfaces. The desirability of using response surfaces depends upon the number of functional evaluations required to build the response surfaces compared to the number required in the direct solution of the equation without approximations. The present study is concerned with evaluating the performance of response surfaces so that a decision can be made as to their effectiveness in optimization applications. In particular, this study focuses on how the quality of approximations is effected by design selection. Polynomial approximations and neural net approximations are considered.

  14. Bird or bat: comparing airframe design and flight performance.

    PubMed

    Hedenström, Anders; Johansson, L Christoffer; Spedding, Geoffrey R

    2009-03-01

    Birds and bats have evolved powered flight independently, which makes a comparison of evolutionary 'design' solutions potentially interesting. In this paper we highlight similarities and differences with respect to flight characteristics, including morphology, flight kinematics, aerodynamics, energetics and flight performance. Birds' size range is 0.002-15 kg and bats' size range is 0.002-1.5 kg. The wingbeat kinematics differ between birds and bats, which is mainly due to the different flexing of the wing during the upstroke and constraints by having a wing of feathers and a skin membrane, respectively. Aerodynamically, bats appear to generate a more complex wake than birds. Bats may be more closely adapted for slow maneuvering flight than birds, as required by their aerial hawking foraging habits. The metabolic rate and power required to fly are similar among birds and bats. Both groups share many characteristics associated with flight, such as for example low amounts of DNA in cells, the ability to accumulate fat as fuel for hibernation and migration, and parallel habitat-related wing shape adaptations. PMID:19258691

  15. Direct formic acid microfluidic fuel cell design and performance evolution

    NASA Astrophysics Data System (ADS)

    Moreno-Zuria, A.; Dector, A.; Cuevas-Muñiz, F. M.; Esquivel, J. P.; Sabaté, N.; Ledesma-García, J.; Arriaga, L. G.; Chávez-Ramírez, A. U.

    2014-12-01

    This work reports the evolution of design, fabrication and testing of direct formic acid microfluidic fuel cells (DFAμFFC), the architecture and channel dimensions are miniaturized from a thousand to few cents of micrometers. Three generations of DFAμFFCs are presented, from the initial Y-shape configuration made by a hot pressing technique; evolving into a novel miniaturized fuel cell based on microfabrication technology using SU-8 photoresist as core material; to the last air-breathing μFFC with enhanced performance and built with low cost materials and processes. The three devices were evaluated in acidic media in the presence of formic acid as fuel and oxygen/air as oxidant. Commercial Pt/C (30 wt. % E-TEK) and Pd/C XC-72 (20 wt. %, E-TEK) were used as cathode and anode electrodes respectively. The air-breathing μFFC generation, delivered up to 27.3 mW cm-2 for at least 30 min, which is a competitive power density value at the lowest fuel flow of 200 μL min-1 reported to date.

  16. MAP Attitude Control System Design and Flight Performance

    NASA Technical Reports Server (NTRS)

    Andrews, S. F.; ODonnell, J. R.; Bauer, Frank H. (Technical Monitor)

    2002-01-01

    The Microwave Anisotropy Probe (MAP) is a follow-on to the Differential Microwave Radiometer (DMR) instrument on the Cosmic Background Explorer (COBE) spacecraft. To make a full-sky map of cosmic microwave background fluctuations, a combination fast spin and slow precession motion will be used that will cover the entire celestial sphere in six months. The spin rate should be an order of magnitude higher than the precession rate, and each rate should be tightly controlled. The sunline angle should be 22.5 +/- 0.25 deg. Sufficient attitude knowledge must be provided to yield instrument pointing to a standard deviation of 1.3 arc-minutes RSS three axes. In addition, the spacecraft must be able to acquire and hold the sunline at initial acquisition, and in the event of a failure. Finally. the spacecraft must be able to slew to the proper burn orientations and to the proper off-sunline attitude to start the compound spin. The design and flight performance of the Attitude Control System on MAP that meets these requirements will be discussed.

  17. Design and performance of a scalable, parallel statistics toolkit.

    SciTech Connect

    Thompson, David C.; Bennett, Janine Camille; Pebay, Philippe Pierre

    2010-11-01

    Most statistical software packages implement a broad range of techniques but do so in an ad hoc fashion, leaving users who do not have a broad knowledge of statistics at a disadvantage since they may not understand all the implications of a given analysis or how to test the validity of results. These packages are also largely serial in nature, or target multicore architectures instead of distributed-memory systems, or provide only a small number of statistics in parallel. This paper surveys a collection of parallel implementations of statistics algorithm developed as part of a common framework over the last 3 years. The framework strategically groups modeling techniques with associated verification and validation techniques to make the underlying assumptions of the statistics more clear. Furthermore it employs a design pattern specifically targeted for distributed-memory parallelism, where architectural advances in large-scale high-performance computing have been focused. Moment-based statistics (which include descriptive, correlative, and multicorrelative statistics, principal component analysis (PCA), and k-means statistics) scale nearly linearly with the data set size and number of processes. Entropy-based statistics (which include order and contingency statistics) do not scale well when the data in question is continuous or quasi-diffuse but do scale well when the data is discrete and compact. We confirm and extend our earlier results by now establishing near-optimal scalability with up to 10,000 processes.

  18. Bedroom Design and Decoration: Gender Differences in Preference and Activity

    ERIC Educational Resources Information Center

    Jones, Randall M.; Taylor, Denise E.; Dick, Andrew J.; Singh, Archana; Cook, Jerry L.

    2007-01-01

    This investigation examined gender differences in niche-building preference and activity among 238 8th and 9th grade boys and girls. A questionnaire was developed to measure both the actual and preferred bedroom content, bedroom design activity, and the level of perceived influence by the immediate and extended family, friends, and social…

  19. Design of Activities on Numerical Representations Based on Cognitive Research

    ERIC Educational Resources Information Center

    Kalifatidou, Eleftheria R.

    2008-01-01

    The results of the cognitive research on numbers' representations can provide a sound theoretical framework to develop educational activities on representing numbers. A program of such activities for a nursery school was designed in order to enable the children to externalize and strengthen their internal representations about numerosity and link…

  20. Supporting "Learning by Design" Activities Using Group Blogs

    ERIC Educational Resources Information Center

    Fessakis, Georgios; Tatsis, Konstantinos; Dimitracopoulou, Angelique

    2008-01-01

    The paper presents a case study of the educational exploitation of group blogging for the implementation of a "learning by design" activity. More specifically, a group of students used a blog as a communication and information management tool in the University course of ICT-enhanced Geometry learning activities. The analysis of the designed…

  1. The discourse of design-based science classroom activities

    NASA Astrophysics Data System (ADS)

    Azevedo, Flávio S.; Martalock, Peggy L.; Keser, Tugba

    2015-06-01

    This paper is an initial contribution to a general theory in which science classroom activity types and epistemological discourse practices are systematically linked. The idea is that activities and discourse are reflexively related, so that different types of science classroom activities (e.g., scientific argumentation, modeling, and design) recruit characteristically distinct forms of participants' (students and teacher) discourse. Such a general theory would eventually map out the full spectrum of discourse practices (and their patterns of manifestation) across various kinds of science classroom activities, and reveal new relationships between forms of both discourse and activities. Because this defines a complex and long-term project, here our aim is simply to delineate this larger theoretical program and to illustrate it with a detailed case study—namely, that of mapping out and characterizing the discourse practices of design- based science classroom activities. To do so, we draw on data from an activity that is prototypically design-based—i.e., one in which students iteratively design and refine an artifact (in this case, pictorial representations of moving objects)—and examine the structure and dynamics of the whole-class discourse practices that emerge around these representational forms. We then compare and contrast these discourse practices to those of an activity that is prototypical of scientific argumentation (taken from the literature)—i.e., one in which students argue between competing theories and explanations of a phenomenon—and begin to illustrate the kinds of insights our theoretical program might afford.

  2. Engineering Design Activities and Conceptual Change in Middle School Science

    ERIC Educational Resources Information Center

    Schnittka, Christine G.

    2009-01-01

    The purpose of this research was to investigate the impact of engineering design classroom activities on conceptual change in science, and on attitudes toward and knowledge about engineering. Students were given a situated learning context and a rationale for learning science in an active, inquiry-based method, and worked in small collaborative…

  3. Satellite Ocean Color Sensor Design Concepts and Performance Requirements

    NASA Technical Reports Server (NTRS)

    McClain, Charles R.; Meister, Gerhard; Monosmith, Bryan

    2014-01-01

    800 nanometers with three additional discrete near infrared (NIR) and shortwave infrared (SWIR) ocean aerosol correction bands. Also, to avoid drift in sensor sensitivity from being interpreted as environmental change, climate change research requires rigorous monitoring of sensor stability. For SeaWiFS, monthly lunar imaging accurately tracked stability at an accuracy of approximately 0.1% that allowed the data to be used for climate studies [2]. It is now acknowledged by the international community that future missions and sensor designs need to accommodate lunar calibrations. An overview of ocean color remote sensing and a review of the progress made in ocean color remote sensing and the variety of research applications derived from global satellite ocean color data are provided. The purpose of this chapter is to discuss the design options for ocean color satellite radiometers, performance and testing criteria, and sensor components (optics, detectors, electronics, etc.) that must be integrated into an instrument concept. These ultimately dictate the quality and quantity of data that can be delivered as a trade against mission cost. Historically, science and sensor technology have advanced in a "leap-frog" manner in that sensor design requirements for a mission are defined many years before a sensor is launched and by the end of the mission, perhaps 15-20 years later, science applications and requirements are well beyond the capabilities of the sensor. Section 3 provides a summary of historical mission science objectives and sensor requirements. This progression is expected to continue in the future as long as sensor costs can be constrained to affordable levels and still allow the incorporation of new technologies without incurring unacceptable risk to mission success. The IOCCG Report Number 13 discusses future ocean biology mission Level-1 requirements in depth.

  4. On the performance of a high head Francis turbine at design and off-design conditions

    NASA Astrophysics Data System (ADS)

    Aakti, B.; Amstutz, O.; Casartelli, E.; Romanelli, G.; Mangani, L.

    2015-01-01

    In the present paper, fully 360 degrees transient and steady-state simulations of a Francis turbine were performed at three operating conditions, namely at part load (PL), best efficiency point (BEP), and high load (HL), using different numerical approaches for the pressure-velocity coupling. The simulation domain includes the spiral casing with stay and guide vanes, the runner and the draft tube. The main target of the investigations is the numerical prediction of the overall performance of the high head Francis turbine model as well as local and integral quantities of the complete machine in different operating conditions. All results were compared with experimental data published by the workshop organization. All CFD simulations were performed at model scale with a new in-house, 3D, unstructured, object-oriented finite volume code within the framework of the open source OpenFOAM library. The novel fully coupled pressure-based solver is designed to solve the incompressible RANS- Equations and is capable of handling multiple references of frame (MRF). The obtained results show that the overall performance is well captured by the simulations. Regarding the local flow distributions within the inlet section of the draft-tube, the axial velocity is better estimated than the circumferential component.

  5. Performance of a newly designed continuous soot monitoring system (COSMOS).

    PubMed

    Miyazaki, Yuzo; Kondo, Yutaka; Sahu, Lokesh K; Imaru, Junichi; Fukushima, Nobuhiko; Kano, Minoru

    2008-10-01

    We designed a continuous soot monitoring system (COSMOS) for fully automated, high-sensitivity, continuous measurement of light absorption by black carbon (BC) aerosols. The instrument monitors changes in transmittance across an automatically advancing quartz fiber filter tape using an LED at a 565 nm wavelength. To achieve measurements with high sensitivity and a lower detectable light absorption coefficient, COSMOS uses a double-convex lens and optical bundle pipes to maintain high light intensity and signal data are obtained at 1000 Hz. In addition, sampling flow rate and optical unit temperature are actively controlled. The inlet line for COSMOS is heated to 400 degrees C to effectively volatilize non-refractory aerosol components that are internally mixed with BC. In its current form, COSMOS provides BC light absorption measurements with a detection limit of 0.45 Mm(-1) (0.045 microg m(-3) for soot) for 10 min. The unit-to-unit variability is estimated to be within +/- 1%, demonstrating its high reproducibility. The absorption coefficients determined by COSMOS agreed with those by a particle soot absorption photometer (PSAP) to within 1% (r2 = 0.97). The precision (+/- 0.60 Mm(-1)) for 10 min integrated data was better than that of PSAP and an aethalometer under our operating conditions. These results showed that COSMOS achieved both an improved detection limit and higher precision for the filter-based light absorption measurements of BC compared to the existing methods.

  6. Computer Program for the Design and Off-Design Performance of Turbojet and Turbofan Engine Cycles

    NASA Technical Reports Server (NTRS)

    Morris, S. J.

    1978-01-01

    The rapid computer program is designed to be run in a stand-alone mode or operated within a larger program. The computation is based on a simplified one-dimensional gas turbine cycle. Each component in the engine is modeled thermo-dynamically. The component efficiencies used in the thermodynamic modeling are scaled for the off-design conditions from input design point values using empirical trends which are included in the computer code. The engine cycle program is capable of producing reasonable engine performance prediction with a minimum of computer execute time. The current computer execute time on the IBM 360/67 for one Mach number, one altitude, and one power setting is about 0.1 seconds. about 0.1 seconds. The principal assumption used in the calculation is that the compressor is operated along a line of maximum adiabatic efficiency on the compressor map. The fluid properties are computed for the combustion mixture, but dissociation is not included. The procedure included in the program is only for the combustion of JP-4, methane, or hydrogen.

  7. Embedded Sensors and Controls to Improve Component Performance and Reliability -- Bench-scale Testbed Design Report

    SciTech Connect

    Melin, Alexander M.; Kisner, Roger A.; Drira, Anis; Reed, Frederick K.

    2015-09-01

    Embedded instrumentation and control systems that can operate in extreme environments are challenging due to restrictions on sensors and materials. As a part of the Department of Energy's Nuclear Energy Enabling Technology cross-cutting technology development programs Advanced Sensors and Instrumentation topic, this report details the design of a bench-scale embedded instrumentation and control testbed. The design goal of the bench-scale testbed is to build a re-configurable system that can rapidly deploy and test advanced control algorithms in a hardware in the loop setup. The bench-scale testbed will be designed as a fluid pump analog that uses active magnetic bearings to support the shaft. The testbed represents an application that would improve the efficiency and performance of high temperature (700 C) pumps for liquid salt reactors that operate in an extreme environment and provide many engineering challenges that can be overcome with embedded instrumentation and control. This report will give details of the mechanical design, electromagnetic design, geometry optimization, power electronics design, and initial control system design.

  8. Thermal and Electrical Analysis of MARS Rover RTG, and Performance Comparison of Alternative Design Options.

    SciTech Connect

    Schock, Alfred; Or, Chuen T; Skrabek, Emanuel A

    1989-09-29

    The paper describes the thermal, thermoelectric and electrical analysis of Radioisotope Thermoelectric Generators (RTGs) for powering the MARS Rover vehicle, which is a critical element of the unmanned Mars Rover and Sample Return mission (MRSR). The work described was part of an RTG design study conducted by Fairchild Space Company for the U.S. Department of Energy, in support of the Jet Propulsion Laboratory's MRSR Project.; A companion paper presented at this conference described a reference mission scenario, al illustrative Rover design and activity pattern on Mars, its power system requirements and environmental constraints, a design approach enabling RTG operation in the Martian atmosphere, and the design and the structural and mass analysis of a conservative baseline RTG employing safety-qualified heat source modules and reliability-proven thermoelectric converter elements.; The present paper presents a detailed description of the baseline RTG's thermal, thermoelectric, and electrical analysis. It examines the effect of different operating conditions (beginning versus end of mission, water-cooled versus radiation-cooled, summer day versus winter night) on the RTG's performance. Finally, the paper describes and analyzes a number of alternative RTG designs, to determine the effect of different power levels (250W versus 125W), different thermoelectric element designs (standard versus short unicouples versus multicouples) and different thermoelectric figures of merit (0.00058K(superscript -1) to 0.000140K (superscript -1) on the RTG's specific power.; The results presented show the RTG performance achievable with current technology, and the performance improvements that would be achievable with various technology developments. It provides a basis for selecting the optimum strategy for meeting the Mars Rover design goals with minimal programmatic risk and cost.; There is a duplicate copy and also a duplicate copy in the ESD files.

  9. Cryogenic propellant management: Integration of design, performance and operational requirements

    NASA Technical Reports Server (NTRS)

    Worlund, A. L.; Jamieson, J. R., Jr.; Cole, T. W.; Lak, T. I.

    1985-01-01

    The integration of the design features of the Shuttle elements into a cryogenic propellant management system is described. The implementation and verification of the design/operational changes resulting from design deficiencies and/or element incompatibilities encountered subsequent to the critical design reviews are emphasized. Major topics include: subsystem designs to provide liquid oxygen (LO2) tank pressure stabilization, LO2 facility vent for ice prevention, liquid hydrogen (LH2) feedline high point bleed, pogo suppression on the Space Shuttle Main Engine (SSME), LO2 low level cutoff, Orbiter/engine propellant dump, and LO2 main feedline helium injection for geyser prevention.

  10. DDE-MITR Status Report of Conceptual Design Activities

    SciTech Connect

    N.E. Woolstenhulme; R.B. Nielson; J.D. Wiest; J.W. Nielsen; G.A. Roth; S.D. Snow

    2012-09-01

    The Design Demonstration Experiment for the Massachusetts Institute of Technology Reactor (DDE-MITR) is intended to facilitate Low Enriched Uranium (LEU) conversion of the MITR by demonstrating the performance and fabrication of the LEU fuel element design through an irradiation test in the Advanced Test Reactor center flux trap. At the time this report was prepared the resources for furthering DDE design work were expected to be postponed. As such, the conceptual design effort to date is summarized herein in order to provide the status of key objectives, notable results, and provisions for future design work. These demonstrate that the DDE-MITR design effort is well on the path to producing a suitable irradiation experiment, but also exhibits several challenges for which timely resolution is recommend in order to facilitate success of the irradiation campaign and ultimate conversion of the MITR.

  11. DDE-MURR Status Report of Conceptual Design Activities

    SciTech Connect

    N.E. Woolstenhulme; R.B. Nielson; M.H. Sprenger; G.K. Housley

    2012-09-01

    The Design Demonstration Experiment for the University of Missouri Research Reactor (DDE-MURR) is intended to facilitate Low Enriched Uranium (LEU) conversion of the MURR by demonstrating the performance and fabrication of the LEU fuel element design through an irradiation test in a 200mm channel at the Belgium Reactor 2. At the time this report was prepared the resources for furthering DDE design work were expected to be postponed. As such, the conceptual design effort to date is summarized herein in order to provide the status of key objectives, notable results, and provisions for future design work. These demonstrate that the DDE-MURR design effort is well on the path to producing a suitable irradiation experiment, but also exhibits several challenges for which timely resolution is recommend in order to facilitate success of the irradiation campaign and ultimate conversion of the MURR.

  12. DDE-NBSR Status Report of Conceptual Design Activities

    SciTech Connect

    N.E. Woolstenhulme; R.B. Nielson; B.P. Durtschi; C.R. Glass; G.A. Roth; D.T. Clark

    2012-09-01

    The Design Demonstration Experiment for the National Bureau of Standard Reactor (DDE-NBSR) is intended to facilitate Low Enriched Uranium (LEU) conversion of the NBSR by demonstrating the performance and fabrication of the LEU fuel element design through an irradiation test in the Advanced Test Reactor center flux trap. At the time this report was prepared the resources for furthering DDE design work were expected to be postponed. As such, the conceptual design effort to date is summarized herein in order to provide the status of key objectives, notable results, and provisions for future design work. These demonstrate that the DDE-NBSR design effort is well on the path to producing a suitable irradiation experiment, but also exhibits several challenges for which timely resolution is recommend in order to facilitate success of the irradiation campaign and ultimate conversion of the NBSR.

  13. Design, fabrication and performance analysis of a 200 W PEM fuel cell short stack

    NASA Astrophysics Data System (ADS)

    Weng, Fang-Bor; Jou, Bo-Shian; Su, Ay; Chan, Shih Hung; Chi, Pei-Hung

    A PEM fuel cell short stack of 200 W capacity, with an active area of 100 cm 2 has been designed and fabricated in-house. The status of unit cell performance was 0.55 W cm -2. Based on the unit cell technology, a short stack has been developed. The proper design of uniform flow distribution, cooling plate and compressed end plate were important to achieve the best performance of the short stack. The performance of four cells stack was analyzed in static and dynamic modes. In the static mode of polarization curve, the stack has peak power density of 0.55 W cm -2 (220 W) at 0.5 V per cell, when the voltage was scanning from low to high voltage (1.5-3.5 V), and resulted in minimum water flooding inside the stack. In this study a series of dynamic loadings were tested to simulate the vehicle acceleration. The fuel cell performances respond to dynamic loading influenced by the hydrogen/air stoichiometric, back pressure, and dynamic-loading time. It was needed high hydrogen stoichiometric and back pressure to maintain high dynamic performance. In the long-time stable power testing, the stack was difficult to maintain at high performance, due to the water flooding at high output power. An adjusting cathode back-pressure method for purging water was proposed to prevent the water flooding at flow channels and maintain the stable output power at 170 W (0.42 W cm -2).

  14. Energy Design Guidelines for High Performance Schools: Hot and Dry Climates.

    ERIC Educational Resources Information Center

    Department of Energy, Washington, DC. Office of Energy Efficiency and Renewable Energy.

    This guide contains recommendations for designing high performance, energy efficient schools located in hot and dry climates. A high performance checklist for designers is included along with several case studies of projects that successfully demonstrated high performance design solutions for hot and dry climates. The guide's 10 sections…

  15. Design and Implementation of a Project-Based Active/Cooperative Engineering Design Course for Freshmen

    ERIC Educational Resources Information Center

    Abdulaal, R. M.; Al-Bahi, A. M.; Soliman, A. Y.; Iskanderani, F. I.

    2011-01-01

    A project-based active/cooperative design course is planned, implemented, assessed and evaluated to achieve several desired engineering outcomes. The course allows freshman-level students to gain professional hands-on engineering design experience through an opportunity to practise teamwork, quality principles, communication skills, life-long…

  16. Designs and performance of microprocessor-controlled knee joints.

    PubMed

    Thiele, Julius; Westebbe, Bettina; Bellmann, Malte; Kraft, Marc

    2014-02-01

    In this comparative study, three transfemoral amputee subjects were fitted with four different microprocessor-controlled exoprosthetic knee joints (MPK): C-Leg, Orion, Plié2.0, and Rel-K. In a motion analysis laboratory, objective gait measures were acquired during level walking at different velocities. Subsequent technical analyses, which involved X-ray computed tomography, identified the functional mechanisms of each device and enabled corroboration of the performance in the gait laboratory by the engineering design of the MPK. Gait measures showed that the mean increase of the maximum knee flexion angle at different walking velocities was closest in value to the unaffected contralateral knee (6.2°/m/s) with C-Leg (3.5°/m/s; Rel-K 17.0°/m/s, Orion 18.3°/m/s, and Plié2.0 28.1°/m/s). Technical analyses corroborated that only with Plié2.0 the flexion resistances were not regulated by microprocessor control at different walking velocities. The muscular effort for the initiation of the swing phase, measured by the minimum hip moment, was found to be lowest with C-Leg (-82.1±14.1 Nm; Rel-K -83.59±17.8 Nm, Orion -88.0±16.3 Nm, and Plié2.0 -91.6±16.5 Nm). Reaching the extension stop at the end of swing phase was reliably executed with both Plié2.0 and C-Leg. Abrupt terminal stance phase extension observed with Plié2.0 and Rel-K could be attributed to the absence of microprocessor control of extension resistance.

  17. Design, performance, and operational characteristics of an FDDI testbed

    SciTech Connect

    Testi, N.; Gossage, S.A.; Ralph, W.D.

    1991-01-01

    Sandia National Laboratories has recently completed a major upgrade of its Central Computing Network (CCN), which is a large heterogeneous network providing scientific supercomputing, file storage, output services, and remote access to network resources. The new network, called the Secure Supercomputing Network (SSN), is based on the HPYERchannel-100 technology platform and is primarily a UNIX-TCP/IP network environment. A migration from the HYPERchannel-100 hardware platform presently in use on the SSN to the Network Systems Corporation (NSC) Fiber Distributed Data Interface (FDDI) hardware platform is currently being considered for several reasons. First, Sandia supports the movement from proprietary hardware and software solutions to standardized solutions. Second, the inherent robustness of the FDDI standard would provide the reliability which is critical to production computing at the Labs. Finally, the potential for tuning the ring for specific applications and connection schemes is an advantage over HYPERchannel. In order to evaluate the NSC FDDI technology platform, an FDDI testbed has been constructed, consisting of two independent FDDI rings. The rings are connected via T3 (44.736 Megabits/second) and T1 (1.544 Megabits/second) link Data Exchange Units (DXUs), and an FE649 FDDI/FDDI router. In addition to a variety of NSC FDDI DXUs and associated host computers, several other vendors' FDDI products are also present on the testbed. Test data on fault isolation and recovery mechanisms, performance, IP routing (within and between rings), IP packet labeling, monitor capabilities, and interoperability'' will be presented. The design and implementation of the underlying fiber optic physical plant will also be discussed.

  18. A Geospatial Model for Remedial Design Optimization and Performance Evaluation

    SciTech Connect

    Madrid, V M; Demir, Z; Gregory, S; Valett, J; Halden, R U

    2002-02-19

    invaluable in optimizing and evaluating the remedial design and performance.

  19. DESIGN AND ANALYSIS OF AN FPGA-BASED ACTIVE FEEDBACK DAMPING SYSTEM

    SciTech Connect

    Xie, Zaipeng; Schulte, Mike; Deibele, Craig Edmond

    2010-01-01

    The Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory is a high-intensity proton-based accelerator that produces neutron beams for neutronscattering research. As the most powerful pulsed neutron source in the world, the SNS accelerator has experienced an unprecedented beam instability that has a wide bandwidth (0 to 300MHz) and fast growth time (10 to100 s). In this paper, we propose and analyze several FPGA-based designs for an active feedback damping system. This signal processing system is the first FPGA-based design for active feedback damping of wideband instabilities in high intensity accelerators. It can effectively mitigate instabilities in highintensity protons beams, reduce radiation, and boost the accelerator s luminosity performance. Unlike existing systems, which are designed using analog components, our FPGA-based active feedback damping system offers programmability while maintaining high performance. To meet the system throughput and latency requirements, our proposed designs are guided by detailed analysis of resource and performance tradeoffs. These designs are mapped onto a reconfigurable platform that includes Xilinx Virtex-II Pro FPGAs and high-speed analog-to-digital and digital-toanalog converters. Our results show that our FPGA-based active feedback damping system can provide increased flexibility and improved signal processing performance that are not feasible with existing analog systems.

  20. Associations of Physical Activity, Sports Participation and Active Commuting on Mathematic Performance and Inhibitory Control in Adolescents

    PubMed Central

    Huang, Tao; Gejl, Anne Kær; Froberg, Karsten

    2016-01-01

    Objectives To examine objectively measured physical activity level, organized sports participation and active commuting to school in relation to mathematic performance and inhibitory control in adolescents. Methods The design was cross-sectional. A convenient sample of 869 sixth and seventh grade students (12–14 years) was invited to participate in the study. A total of 568 students fulfilled the inclusion criteria and comprised the final sample for this study. Mathematic performance was assessed by a customized test and inhibitory control was assessed by a modified Eriksen flanker task. Physical activity was assessed with GT3X and GT3X+ accelerometers presented in sex-specific quartiles of mean counts per minute and mean minutes per day in moderate-to-vigorous physical activity. Active commuting and sports participation was self-reported. Mixed model regression was applied. Total physical activity level was stratified by bicycling status in order to bypass measurement error subject to the accelerometer. Results Non-cyclists in the 2nd quartile of counts per minute displayed a higher mathematic score, so did cyclists in the 2nd and 3rd quartile of moderate-to-vigorous physical activity relative to the least active quartile. Non-cyclists in the 3rd quartile of counts per minute had an improved reaction time and cyclists in the 2nd quartile of counts per minute and moderate-to-vigorous physical activity displayed an improved accuracy, whereas non-cyclists in the 2nd quartile of counts per minute showed an inferior accuracy relative to the least active quartile. Bicycling to school and organized sports participation were positively associated with mathematic performance. Conclusions Sports participation and bicycling were positively associated with mathematic performance. Results regarding objectively measured physical activity were mixed. Although, no linear nor dose-response relationship was observed there was no indication of a higher activity level impairing the

  1. Data path design considerations for a high performance VLSI multiprocessor

    SciTech Connect

    Lee, D.

    1987-01-01

    A VLSI data path implementation for the SPUR (Symbolic Processing Using RISCs) processor is presented. There are many tradeoffs to be considered in the design of a microprocessor data path. Often, these tradeoffs are interrelated and thus increase the complexity of the design. This report focuses on the design of the CMOS data path with the tradeoffs considered throughout the implementation of the data path for the SPUR CPU.

  2. Design and Validation of MAPS for Educators: A Performance Support System to Guide Media Selection for Lesson Design

    ERIC Educational Resources Information Center

    Hung, Wei-Chen; Kalota, Faisal

    2013-01-01

    The importance of adopting technology-supported performance systems for on-the-job learning and training is well-recognized in a networked economy. In this study, we present a performance support system (PSS) designed to support technology integration for lesson design. The goal is to support educators in the development of appropriate and…

  3. An Action Research Study on the Effect of Interactive Technology and Active Learning on Student Performance

    ERIC Educational Resources Information Center

    Bear, Teresa J.

    2013-01-01

    This quantitative action science research study utilized a causal-comparative experimental research design in order to determine if the use of student response systems (clickers), as an active learning strategy in a community college course, improved student performance in the course. Students in the experimental group (n = 26) used clickers to…

  4. Layered shielding design for an active neutron interrogation system

    NASA Astrophysics Data System (ADS)

    Whetstone, Zachary D.; Kearfott, Kimberlee J.

    2016-08-01

    The use of source and detector shields in active neutron interrogation can improve detector signal. In simulations, a shielded detector with a source rotated π/3 rad relative to the opening decreased neutron flux roughly three orders of magnitude. Several realistic source and detector shield configurations were simulated. A layered design reduced neutron and secondary photon flux in the detector by approximately one order of magnitude for a deuterium-tritium source. The shield arrangement can be adapted for a portable, modular design.

  5. In Search of Design Principles for Developing Digital Learning and Performance Support for a Student Design Task

    ERIC Educational Resources Information Center

    Bollen, Lars; van der Meij, Hans; Leemkuil, Henny; McKenney, Susan

    2015-01-01

    A digital learning and performance support environment for university student design tasks was developed. This paper describes on the design rationale, process, and the usage results to arrive at a core set of design principles for the construction of such an environment. We present a collection of organizational, technical, and course-related…

  6. Design and Performance Frameworks for Constructing Problem-Solving Simulations

    ERIC Educational Resources Information Center

    Stevens, Rons; Palacio-Cayetano, Joycelin

    2003-01-01

    Rapid advancements in hardware, software, and connectivity are helping to shorten the times needed to develop computer simulations for science education. These advancements, however, have not been accompanied by corresponding theories of how best to design and use these technologies for teaching, learning, and testing. Such design frameworks…

  7. DESIGN AND PERFORMANCE OF A LOW FLOW RATE INLET

    EPA Science Inventory

    Several ambient air samplers that have been designated by the U. S. EPA as Federal Reference Methods (FRMs) for measuring particulate matter nominally less than 10 um (PM10) include the use of a particular inlet design that aspirates particulate matter from the atmosphere at 1...

  8. DDE-MURR Status Report of Conceptual Design Activities

    SciTech Connect

    N.E. Woolstenhulme; R.B. Nielson; M.H. Sprenger; G.K. Housley

    2013-09-01

    The Design Demonstration Experiment for the University of Missouri Research Reactor (DDE-MURR) is intended to facilitate Low Enriched Uranium (LEU) conversion of the MURR by demonstrating the performance and fabrication of the LEU fuel element design through an irradiation test in a 200mm channel at the Belgium Reactor 2 (BR2). Revision 0 of this report was prepared at the end of government fiscal year 2012 when most of the resources for furthering DDE design work were expected to be postponed. Hence, the conceptual design efforts were summarized to provide the status of key objectives, notable results, and provisions for future design work. Revision 1 of this report was prepared at the end of fiscal year 2013 in order to include results from a neutronic study performed by BR2, to incorporate further details that had been achieved in the engineering sketches of the irradiation devices, and to provide an update of the DDE-MURR campaign in relation to program objectives and opportunities for its eventual irradiation. These updates were purposed to bring the DDE-MURR conceptual design to level of maturity similar to that of the other two DDE efforts (DDE-MITR and DDE-NBSR). This report demonstrates that the DDE-MURR design effort is well on the path to producing a suitable irradiation experiment, but also puts forth several recommendations in order to facilitate success of the irradiation campaign.

  9. The CF6 Jet Engine Performance Improvement - Low Pressure Turbine Active Clearance Control

    NASA Technical Reports Server (NTRS)

    Beck, B. D.; Fasching, W. A.

    1982-01-01

    A low pressure turbine (LPT) active clearance control (ACC) cooling system was developed to reduce the fuel consumption of current CF6-50 turbofan engines for wide bodied commercial aircraft. The program performance improvement goal of 0.3% delta sfc was determined to be achievable with an improved impingement cooling system. The technology enables the design of an optimized manifold and piping system which is capable of a performance gain of 0.45% delta sfc.

  10. Gearbox design for uncertain load requirements using active robust optimization

    NASA Astrophysics Data System (ADS)

    Salomon, Shaul; Avigad, Gideon; Purshouse, Robin C.; Fleming, Peter J.

    2016-04-01

    Design and optimization of gear transmissions have been intensively studied, but surprisingly the robustness of the resulting optimal design to uncertain loads has never been considered. Active Robust (AR) optimization is a methodology to design products that attain robustness to uncertain or changing environmental conditions through adaptation. In this study the AR methodology is utilized to optimize the number of transmissions, as well as their gearing ratios, for an uncertain load demand. The problem is formulated as a bi-objective optimization problem where the objectives are to satisfy the load demand in the most energy efficient manner and to minimize production cost. The results show that this approach can find a set of robust designs, revealing a trade-off between energy efficiency and production cost. This can serve as a useful decision-making tool for the gearbox design process, as well as for other applications.

  11. Aerodynamic Performance of Electro-Active Membrane Wings

    NASA Astrophysics Data System (ADS)

    Barbu, Ioan-Alexandru; de Kat, Roeland; Ganapathisubramani, Bharathram

    2014-11-01

    Electro-active polymers offer due to their multivariate compliant nature a great potential for integrating the lift producing system and the control system into one. This work presents the first step in describing both the mechanical and aerodynamic performance of such materials and focuses on both understanding their behaviour in aerodynamic applications and on analysing their aerodynamic performance. Photogrammetry and load measurements are conducted in a wind tunnel for both silicone-based and acrylic-based membranes at zero prestrain supported in a perimeter reinforced frame in electrically passive, active and pulsing conditions. A wide range of fixed voltages and pulsing frequencies are considered. Due to their hyper-viscoelastic nature, both short and long term hysteresis analysis are conducted in terms of aerodynamic performance. Along with these tests, analyses of the effects of the percentage electrode area and silicone content on aerodynamic performance are conducted.

  12. The effects of age and sex on mental rotation performance, verbal performance, and brain electrical activity.

    PubMed

    Roberts, Jonathan E; Bell, Martha Ann

    2002-05-01

    This study examined the effects of age and sex on mental rotation performance, verbal performance, and brain-wave activity. Thirty-two 8-year-olds (16 boys) and 32 college students (16 men) had EEG recorded at baseline and while performing four computerized tasks: a two-dimensional (2D) gingerbread man mental rotation, a 2D alphanumeric mental rotation, of three-dimensional (3D) basketball player mental rotation, and lexical decision making. Additionally, participants completed a paper- and pencil water level task and an oral verbal fluency task. On the 2D alphanumeric and 3D basketball player mental rotation tasks, men performed better than boys, but the performance of women and girls did not differ. On the water level task, men performed better than women whereas there was no difference between boys and girls. No sex differences were found on the 2D gingerbread man mental rotation, lexical decision-making, and verbal fluency tasks. EEG analyses indicated that men exhibited left posterior temporal activation during the 2D alphanumeric task and that men and boys both exhibited greater left parietal activation than women and girls during the 2D gingerbread man task. On the 3D basketball player mental rotation task, all participants exhibited greater activation of the right parietal area than the left parietal area. These data give insight into the brain activity and cognitive development changes that occur between childhood and adulthood.

  13. Performance of Straight Steel Fibres Reinforced Alkali Activated Concrete

    NASA Astrophysics Data System (ADS)

    Faris, Meor Ahmad; Bakri Abdullah, Mohd Mustafa Al; Nizar Ismail, Khairul; Muniandy, Ratnasamy; Putra Jaya, Ramadhansyah

    2016-06-01

    This paper focus on the performance of alkali activated concrete produced by using fly ash activated by sodium silicate and sodium hydroxide solutions. These alkali activated concrete were reinforced with straight steel fibres with different weight percentage starting from 0 % up to 5 %. Chemical composition of raw material in the production alkali activated concrete which is fly ash was first identified by using X-ray fluorescence. Results reveal there have an effect of straight steel fibres inclusion to the alkali activated concrete. Highest compressive strength of alkali activated concrete which is 67.72 MPa was obtained when 3 % of straight fibres were added. As well as flexural strength, highest flexural strength which is 6.78 MPa was obtained at 3 % of straight steel fibres inclusions.

  14. Improved performance design of gallium arsenide solar cells for space

    NASA Technical Reports Server (NTRS)

    Parekh, R. H.; Barnett, A. M.

    1984-01-01

    An improved design, shallow junction heteroface, n-p, gallium arsenide solar cell for space applications is reported, with a predicted AM0 efficiency in the 21.9 to 23.0 percent range. The optimized n-p structure, while slightly more efficient, has the added advantage of being less susceptible to radiation-induced degradation by virtue of this thin top junction layer. Detailed spectral response curves and an analysis of the loss mechanisms are reported. The details of the design are readily measurable. The optimized designs were reached by quantifying the dominant loss mechanisms and then minimizing them by using computer simulations.

  15. Design and performance of the LCLS cavity BPM system.

    SciTech Connect

    Lill, R.; Norum, E.; Morrison, L.; Sereno, N.; Waldschmidt, G.; Walters, D.; Smith, S.; Straumann, T.; SLAC

    2008-01-01

    In this paper we present the design of the beam position monitor (BPM) system for the LCLS undulator, which features a high-resolution X-band cavity BPM. Each BPM has a TM{sub 010} monopole reference cavity and a TM{sub 110} dipole cavity designed to operate at a center frequency of 11.384 GHz. The signal processing electronics features a low- noise single-stage three-channel heterodyne receiver that has selectable gain and a phase locking local oscillator. We will discuss the system specifications, design, and prototype test results.

  16. Current Research in Aircraft Tire Design and Performance

    NASA Technical Reports Server (NTRS)

    Tanner, J. A.; Mccarthy, J. L.; Clark, S. K.

    1981-01-01

    A review of the tire research programs which address the various needs identified by landing gear designers and airplane users is presented. The experimental programs are designed to increase tire tread lifetimes, relate static and dynamic tire properties, establish the tire hydroplaning spin up speed, study gear response to tire failures, and define tire temperature profiles during taxi, braking, and cornering operations. The analytical programs are aimed at providing insights into the mechanisms of heat generation in rolling tires and developing the tools necessary to streamline the tire design process and to aid in the analysis of landing gear problems.

  17. Electroencephalogram associations to cognitive performance in clinically active nurses.

    PubMed

    Lees, Ty; Khushaba, Rami; Lal, Sara

    2016-07-01

    Cognitive impairment is traditionally identified via cognitive screening tools that have limited ability in detecting early or transitional stages of impairment. The dynamic nature of physiological variables such as the electroencephalogram (EEG) may provide alternate means for detecting these transitions. However, previous research examining EEG and cognitive performance is largely confined to samples with diagnosed cognitive impairments, and research examining non-impaired, and occupation specific samples, is limited. The present study aimed to investigate the associations between frontal pole and central EEG and cognitive performance in a sample of male and female nurses, and to determine the significance of these associations. Fifty seven nurses participated in the study, in which two lead bipolar EEG was recorded at positions Fp1 (frontal polar), Fp2, C3 (central) and C4 during a baseline and an active phase involving the common neuropsychological Stroop test. Participants' cognitive performance was assessed using the mini-mental state exam (MMSE) and Cognistat screening tools. Significant correlations between EEG beta activity and the outcome of MMSE and Cognistat were revealed, where an increased beta activity was associated to an increased global cognitive performance. Additionally, domain specific cognitive performance was also significantly associated to various EEG variables. The study identified potential EEG biomarkers for global and domain specific cognitive performance, and provides initial groundwork for the development of future EEG based biomarkers for detection of cognitive pathologies. PMID:27244262

  18. Design and Performance Measurement of the Mercury Laser Altimeter

    NASA Technical Reports Server (NTRS)

    Sun, Xiao-Li; Cavanaugh, John F.; Smith, James C.; Bartels, Arlin E.

    2004-01-01

    We report the design and test results of the Mercury Laser Altimeter on MESSENGER mission to be launched in May 2004. The altimeter will provide planet surface topography measurements via laser pulse time of flight.

  19. Design and performance characterization of the LCOGTN One-Meter Telescope optical tube assembly

    NASA Astrophysics Data System (ADS)

    Haldeman, Benjamin J.; Haynes, Rachel M.; Posner, Vincent; Tufts, Joseph R.; Pickles, Andrew J.; Dubberley, Matthew A.

    2010-07-01

    Scientific performance specifications, a necessity for ease of commissioning and minimal maintenance, and a desire for automated sensing and remote collimation have led to novel designs and features in LCOGT's one-meter Optical Tube Assembly (OTA). We discuss the design and performance of the quasi-RC optical system with 18 point whiffletree and radial hub mount. Position probes and IR temperature sensors on the primary and secondary mirrors give feedback for active collimation and thermal control. A carbon fiber/epoxy composite truss, with unique spherical node connections, mounts to parallel and offset Invar vanes. A flexure based, closed loop, 3-DOF secondary mirror mechanism is used for tip/tilt collimation. The optics and deflections of the OTA components were iteratively designed for passive collimation with a changing gravity vector. We present the FEA predictions, measured deflections, and measured hysteresis for many of the components. Vibration modes, amplitudes, and damping of the system are presented with an FFT frequency analysis. Thermal CTE effects on loading and focal position are quantified. All of these system effects are then related to the overall scientific performance of the 1.0 m telescope.

  20. Design and performance evaluation of a new jetting dispenser system using two piezostack actuators

    NASA Astrophysics Data System (ADS)

    Jeon, Juncheol; Hong, Seung-Min; Choi, Minkyu; Choi, Seung-Bok

    2015-01-01

    This paper presents a new jetting dispenser system which is adaptable to various packaging processes such as light emitting diode packaging and flip chip packaging. The proposed dispenser system is driven by piezostack actuators and a lever-hinge mechanism. In order to improve jetting performances such as accurate dispensed amount and adaptability to high viscosity fluid, two piezostack actuators are used. By activating the two actuators dually, the angular displacement of the lever can be controlled to produce a required motion of the needle. Firstly, the configuration and working principles of the proposed jetting system are explained, the design of the dispenser is then conducted and significant geometric dimensions of the dispenser are presented. In the design process, several operational requirements such as the maximum needle stroke, operational frequency, and amplification ratio of the lever-hinge are considered. The principal design parameters of the jetting dispenser system are determined from static and modal analysis using the finite element analysis. After obtaining the dimensional characteristics, the control logic for the dispensing operation is explained using a feed-forward controller. The piezostack-driven jetting dispenser system and control devices are then fabricated to evaluate the dispenser performance. It is shown experimentally that by changing the input voltage conditions, the amount of fluid dispensed by the proposed jetting system can be effectively controlled to achieve the desired jetting performance.

  1. Performance of truss panels with kagome cores and design of a high authority shape morphing structure

    NASA Astrophysics Data System (ADS)

    Wang, Ju

    This dissertation includes two parts: First, the performance of a light weight truss panels with Kagome cores; Second, design of a high authority morphing structure for hinging and twisting. The performance characteristics of a truss core sandwich panel design based on the 3D Kagome are measured and compared with earlier numerical simulations and the consistency is demonstrated. Panels are fabricated by investment casting and tested in compression, shear and 3-point bending. The isotropic nature of this core design is confirmed. The superior performance relative to truss designs based on the tetrahedron is demonstrated and attributed to the greater resistance to plastic buckling at the equivalent core density. The failed samples are examined in the scanning electron microscope and imperfections are identified to have caused the premature failures. A concept for a high authority shape morphing plate is described. The design incorporates an active Kagome back-plane capable of changing the shape of a solid face by transmitting loads through a tetrahedral core. The two shape deformations to be achieved and demonstrated consist of hinging and twisting. The design is performed by a combination of analytic estimation and numerical simulation, guided by previous assessments of the Kagome configuration. The objective is to ascertain designs that provide the maximum edge displacement subjected to specified passive load. An optimization is used to ascertain the largest displacement achievable within the force capacity of the actuators. These displacements have been demonstrated and shown to correspond with values predicted by numerical simulation. Non-linear effects, such as face wrinkling, are probed by using a finite element method and the fidelity of the results assessed through comparison with measurements. The numerical results are used to validate a dimensional analysis of trends in the actuation resistance of the structure with geometry, as well as the passive load

  2. Revised MITG design, fabrication procedure, and performance predictions

    SciTech Connect

    Schock, A.

    1983-01-01

    The design, analysis, and key features of the Modular Isotopic Thermoelectric Generator (MITG) were described in a 1981 IECEC paper; and the design, fabrication, testing, and post-test analysis of test assemblies simulating prototypical MITG modules were described in preceding papers in these proceedings. These analyses succeeded in identifying and explaining the principal causes of thermal-stress problems encountered in the tests, and in confirming the effectiveness of design changes for alleviating them. The present paper presents additional design improvements for solving these and other problems, and describes new thermoelectric material properties generated by independent laboratories over the past two years. Based on these changes and on a revised fabrication procedure, it presents a reoptimization of the MITG design and computes the power-to-weight ratio for the revised design. That ratio is appreciably lower than the 1981 prediction, primarily because of changes in material properties; but it is still much higher than the specific power of current-generation RTGs.

  3. Improving the lens design and performance of a contemporary electromagnetic shock wave lithotripter.

    PubMed

    Neisius, Andreas; Smith, Nathan B; Sankin, Georgy; Kuntz, Nicholas John; Madden, John Francis; Fovargue, Daniel E; Mitran, Sorin; Lipkin, Michael Eric; Simmons, Walter Neal; Preminger, Glenn M; Zhong, Pei

    2014-04-01

    The efficiency of shock wave lithotripsy (SWL), a noninvasive first-line therapy for millions of nephrolithiasis patients, has not improved substantially in the past two decades, especially in regard to stone clearance. Here, we report a new acoustic lens design for a contemporary electromagnetic (EM) shock wave lithotripter, based on recently acquired knowledge of the key lithotripter field characteristics that correlate with efficient and safe SWL. The new lens design addresses concomitantly three fundamental drawbacks in EM lithotripters, namely, narrow focal width, nonidealized pulse profile, and significant misalignment in acoustic focus and cavitation activities with the target stone at high output settings. Key design features and performance of the new lens were evaluated using model calculations and experimental measurements against the original lens under comparable acoustic pulse energy (E+) of 40 mJ. The -6-dB focal width of the new lens was enhanced from 7.4 to 11 mm at this energy level, and peak pressure (41 MPa) and maximum cavitation activity were both realigned to be within 5 mm of the lithotripter focus. Stone comminution produced by the new lens was either statistically improved or similar to that of the original lens under various in vitro test conditions and was significantly improved in vivo in a swine model (89% vs. 54%, P = 0.01), and tissue injury was minimal using a clinical treatment protocol. The general principle and associated techniques described in this work can be applied to design improvement of all EM lithotripters.

  4. Design of multitarget activity landscapes that capture hierarchical activity cliff distributions.

    PubMed

    Dimova, Dilyana; Wawer, Mathias; Wassermann, Anne Mai; Bajorath, Jürgen

    2011-02-28

    An activity landscape model of a compound data set can be rationalized as a graphical representation that integrates molecular similarity and potency relationships. Activity landscape representations of different design are utilized to aid in the analysis of structure-activity relationships and the selection of informative compounds. Activity landscape models reported thus far focus on a single target (i.e., a single biological activity) or at most two targets, giving rise to selectivity landscapes. For compounds active against more than two targets, landscapes representing multitarget activities are difficult to conceptualize and have not yet been reported. Herein, we present a first activity landscape design that integrates compound potency relationships across multiple targets in a formally consistent manner. These multitarget activity landscapes are based on a general activity cliff classification scheme and are visualized in graph representations, where activity cliffs are represented as edges. Furthermore, the contributions of individual compounds to structure-activity relationship discontinuity across multiple targets are monitored. The methodology has been applied to derive multitarget activity landscapes for compound data sets active against different target families. The resulting landscapes identify single-, dual-, and triple-target activity cliffs and reveal the presence of hierarchical cliff distributions. From these multitarget activity landscapes, compounds forming complex activity cliffs can be readily selected.

  5. Performance of pavements designed with low-cost materials

    NASA Astrophysics Data System (ADS)

    Grau, R. W.; Yrjanson, W. A.; Packard, R. G.; Barksdale, R. D.; Potts, C. F.; Ruth, B. E.; Smith, L. L.; Huddleston, I. J.; Vinson, T. S.; Hicks, R. G.

    1980-04-01

    The following areas are discussed. Utilization of marginal aggregate materials for secondary road surface layers; econocrete pavements; current practices; construction and performance of sand-asphalt bases and performance of sand-asphalt and limerock pavements in Florida. Cement stabilization of degrading aggregates use of crushed stone screenings in highway construction (abridgement); and sulfur-asphalt pavement technology are also reviewed.

  6. Predictors of Future Performance in Architectural Design Education

    ERIC Educational Resources Information Center

    Roberts, A. S.

    2007-01-01

    The link between academic performance in secondary education and the subsequent performance of students studying architecture at university level is commonly questioned by educators and admissions tutors. This paper investigates the potential for using measures of cognitive style and spatial ability as predictors of future potential in…

  7. Using Fall to Design Activities: In the Classroom.

    ERIC Educational Resources Information Center

    Grambo, Gregory

    1994-01-01

    Examples of fall activities to bring the natural world into the classroom are offered including conducting a simple chromatography experiment on leaves, correlating number of seeds with the lines on pumpkins, planting colored corn kernels, and designing and making scarecrows. (DB)

  8. Designing the Perfect Plant: Activities to Investigate Plant Ecology

    ERIC Educational Resources Information Center

    Lehnhoff, Erik; Woolbaugh, Walt; Rew, Lisa

    2008-01-01

    Plant ecology is an important subject that often receives little attention in middle school, as more time during science classes is devoted to plant biology. Therefore, the authors have developed a series of activities, including a card game--Designing the Perfect Plant--to introduce student's to plant ecology and the ecological trade offs…

  9. ALARA Design Review for the Resumption of the Plutonium Finishing Plant (PFP) Cementation Process Project Activities

    SciTech Connect

    DAYLEY, L.

    2000-06-14

    The requirements for the performance of radiological design reviews are codified in 10CFR835, Occupational Radiation Protection. The basic requirements for the performance of ALARA design reviews are presented in the Hanford Site Radiological Control Manual (HSRCM). The HSRCM has established trigger levels requiring radiological reviews of non-routine or complex work activities. These requirements are implemented in site procedures HNF-PRO-1622 and 1623. HNF-PRO-1622 Radiological Design Review Process requires that ''radiological design reviews [be performed] of new facilities and equipment and modifications of existing facilities and equipment''. In addition, HNF-PRO-1623 Radiological Work Planning Process requires a formal ALARA Review for planned activities that are estimated to exceed 1 person-rem total Dose Equivalent (DE). The purpose of this review is to validate that the original design for the PFP Cementation Process ensures that the principles of ALARA (As Low As Reasonably Achievable) were included in the original project design. That is, that the design and operation of existing Cementation Process equipment and processes allows for the minimization of personnel exposure in its operation, maintenance and decommissioning and that the generation of radioactive waste is kept to a minimum.

  10. Asteroid Redirect Crewed Mission Nominal Design and Performance

    NASA Technical Reports Server (NTRS)

    Condon, Gerald; williams, Jacob

    2014-01-01

    Mission (ARCM) nominal design and performance costs associated with an Orion based crewed rendezvous mission to a captured asteroid in an Earth-Moon DRO. The ARM study includes two fundamental mission phases: 1) The Asteroid Redirect Robotic Mission (ARRM) and 2) the ARCM. The ARRM includes a solar electric propulsion based robotic asteroid return vehicle (ARV) sent to rendezvous with a selected near Earth asteroid, capture it, and return it to a DRO in the Earth-Moon vicinity. The DRO is selected over other possible asteroid parking orbits due to its achievability (by both the robotic and crewed vehicles) and by its stability (e.g., no orbit maintenance is required). After the return of the asteroid to the Earth-Moon vicinity, the ARCM is executed and carries a crew of two astronauts to a DRO to rendezvous with the awaiting ARV with the asteroid. The outbound and inbound transfers employ lunar gravity assist (LGA) flybys to reduce the Orion propellant requirement for the overall nominal mission, which provides a nominal mission with some reserve propellant for possible abort situations. The nominal mission described in this report provides a better understanding of the mission considerations as well as the feasibility of such a crewed mission, particularly with regard to spacecraft currently undergoing development, such as the Orion vehicle and the Space Launch System (SLS).

  11. Extra-Curricular Activities and Academic Performance in Secondary Students

    ERIC Educational Resources Information Center

    Moriana, Juan Antonio; Alos, Francisco; Alcala, Rocio; Pino, Maria-Jose; Herruzo, Javier; Ruiz, Rosario

    2006-01-01

    Introduction: In this paper we study the possible influence of extra-curricular activities (study-related and/or sports) on academic performance of first- and second-year pupils in "Educacion Secundaria Obligatoria (ESO)" [N.T. seventh- and eighth-graders]. Method: We randomly selected 12 schools in the city (9 public and 3 private), and randomly…

  12. Prior-to-Exam: What Activities Enhance Performance?

    ERIC Educational Resources Information Center

    Rhoads, C. J.; Healy, Therese

    2013-01-01

    Can instructors impact their student performance by recommending an activity just prior to taking an exam? In this study, college students were randomly assigned to one of three treatment groups (study, exercise, or meditation) or a control group. Each group was given two different types of tests; a traditional concept exam, and a non-traditional…

  13. Preliminary Axial Flow Turbine Design and Off-Design Performance Analysis Methods for Rotary Wing Aircraft Engines. Part 1; Validation

    NASA Technical Reports Server (NTRS)

    Chen, Shu-cheng, S.

    2009-01-01

    For the preliminary design and the off-design performance analysis of axial flow turbines, a pair of intermediate level-of-fidelity computer codes, TD2-2 (design; reference 1) and AXOD (off-design; reference 2), are being evaluated for use in turbine design and performance prediction of the modern high performance aircraft engines. TD2-2 employs a streamline curvature method for design, while AXOD approaches the flow analysis with an equal radius-height domain decomposition strategy. Both methods resolve only the flows in the annulus region while modeling the impact introduced by the blade rows. The mathematical formulations and derivations involved in both methods are documented in references 3, 4 for TD2-2) and in reference 5 (for AXOD). The focus of this paper is to discuss the fundamental issues of applicability and compatibility of the two codes as a pair of companion pieces, to perform preliminary design and off-design analysis for modern aircraft engine turbines. Two validation cases for the design and the off-design prediction using TD2-2 and AXOD conducted on two existing high efficiency turbines, developed and tested in the NASA/GE Energy Efficient Engine (GE-E3) Program, the High Pressure Turbine (HPT; two stages, air cooled) and the Low Pressure Turbine (LPT; five stages, un-cooled), are provided in support of the analysis and discussion presented in this paper.

  14. DOE site performance assessment activities. Radioactive Waste Technical Support Program

    SciTech Connect

    Not Available

    1990-07-01

    Information on performance assessment capabilities and activities was collected from eight DOE sites. All eight sites either currently dispose of low-level radioactive waste (LLW) or plan to dispose of LLW in the near future. A survey questionnaire was developed and sent to key individuals involved in DOE Order 5820.2A performance assessment activities at each site. The sites surveyed included: Hanford Site (Hanford), Idaho National Engineering Laboratory (INEL), Los Alamos National Laboratory (LANL), Nevada Test Site (NTS), Oak Ridge National Laboratory (ORNL), Paducah Gaseous Diffusion Plant (Paducah), Portsmouth Gaseous Diffusion Plant (Portsmouth), and Savannah River Site (SRS). The questionnaire addressed all aspects of the performance assessment process; from waste source term to dose conversion factors. This report presents the information developed from the site questionnaire and provides a comparison of site-specific performance assessment approaches, data needs, and ongoing and planned activities. All sites are engaged in completing the radioactive waste disposal facility performance assessment required by DOE Order 5820.2A. Each site has achieved various degrees of progress and have identified a set of critical needs. Within several areas, however, the sites identified common needs and questions.

  15. A performance-oriented power transformer design methodology using multi-objective evolutionary optimization.

    PubMed

    Adly, Amr A; Abd-El-Hafiz, Salwa K

    2015-05-01

    Transformers are regarded as crucial components in power systems. Due to market globalization, power transformer manufacturers are facing an increasingly competitive environment that mandates the adoption of design strategies yielding better performance at lower costs. In this paper, a power transformer design methodology using multi-objective evolutionary optimization is proposed. Using this methodology, which is tailored to be target performance design-oriented, quick rough estimation of transformer design specifics may be inferred. Testing of the suggested approach revealed significant qualitative and quantitative match with measured design and performance values. Details of the proposed methodology as well as sample design results are reported in the paper.

  16. A performance-oriented power transformer design methodology using multi-objective evolutionary optimization

    PubMed Central

    Adly, Amr A.; Abd-El-Hafiz, Salwa K.

    2014-01-01

    Transformers are regarded as crucial components in power systems. Due to market globalization, power transformer manufacturers are facing an increasingly competitive environment that mandates the adoption of design strategies yielding better performance at lower costs. In this paper, a power transformer design methodology using multi-objective evolutionary optimization is proposed. Using this methodology, which is tailored to be target performance design-oriented, quick rough estimation of transformer design specifics may be inferred. Testing of the suggested approach revealed significant qualitative and quantitative match with measured design and performance values. Details of the proposed methodology as well as sample design results are reported in the paper. PMID:26257939

  17. Block Design Test Performance as a Function of Race and Block Color.

    ERIC Educational Resources Information Center

    Mitchell, Nancy B.; Pollack, Robert H.

    The purpose of this study was to see if a relationship between color sensitivity and skin pigmentation would affect performance on the WISC block design subtest when both the standard red/white design and the blue/yellow design were used. It was hypothesized that the white children would perform better overall because black children have been…

  18. Research in the design of high-performance reconfigurable systems

    NASA Technical Reports Server (NTRS)

    Slotnick, D. L.

    1985-01-01

    The initial control and programming philosophies of the RELAPSE are discussed. A block diagram showing the relationship of the Arithmetic Units (composed of Stages and Bit Processors), to the Functional Units, and other components of the RELAPSE is used to guide this discussion. The latest version of the Bit Processor design is presented. Included is a detailed discussion of the Bit Processor's new scratch pad memory component. The section also clarifies the usage of the Bit Processor's processing registers, and Input/Output functions. The final design phase of the Arithmetic Unit is underway by a study of the Proposed IEEE Floating Point Standard. The decisions on conformation to this standard will be used as inputs into the finalization of the designs of the Bit Processor, Stage, and Arithmetic Units of the RELAPSE.

  19. Italsat in-orbit test transponder design and performance

    NASA Astrophysics Data System (ADS)

    Mott, R.; Estep, G.; Kelly, W.; Yogev, I.; di Fiore, L.; Talcott, J.; Williams, A.; Assal, F.

    1992-03-01

    This paper describes the design, fabrication, and test of the Italsat in-orbit test (IOT) RF bypass transponder mounted on board the Italsat multibeam spacecraft, which was launched in January 1991. It is believed that the in-orbit test transponder (IOTT) contains the first monolithic microwave integrated circuits (MMICs) ever launched into space on a communications satellite. The IOTT bypasses the demodulator, basebands switchboard, and modulator of the multibeam package of the Italsat spacecraft payload, enabling full characterization of the satellite's transponders using well-established IOT techniques. This space-qualified design incorporates custom-designed gallium arsenide MMIC Ku-band amplifiers, lightweight waveguide Ku-band channel filters, electronic power conditioner, and combined IOTT telemetry and command circuitry.

  20. The acoustic performance of double-skin facades: A design support tool for architects

    NASA Astrophysics Data System (ADS)

    Batungbakal, Aireen

    This study assesses and validates the influence of measuring sound in the urban environment and the influence of glass facade components in reducing sound transmission to the indoor environment. Among the most reported issues affecting workspaces, increased awareness to minimize noise led building designers to reconsider the design of building envelopes and its site environment. Outdoor sound conditions, such as traffic noise, challenge designers to accurately estimate the capability of glass facades in acquiring an appropriate indoor sound quality. Indicating the density of the urban environment, field-tests acquired existing sound levels in areas of high commercial development, employment, and traffic activity, establishing a baseline for sound levels common in urban work areas. Composed from the direct sound transmission loss of glass facades simulated through INSUL, a sound insulation software, data is utilized as an informative tool correlating the response of glass facade components towards existing outdoor sound levels of a project site in order to achieve desired indoor sound levels. This study progresses to link the disconnection in validating the acoustic performance of glass facades early in a project's design, from conditioned settings such as field-testing and simulations to project completion. Results obtained from the study's facade simulations and facade comparison supports that acoustic comfort is not limited to a singular solution, but multiple design options responsive to its environment.

  1. Rapid Euler CFD for High-Performance Aircraft Design

    NASA Technical Reports Server (NTRS)

    Charlton, Eric F.

    2004-01-01

    The goal here was to present one approach to rapid CFD for S&C using an unstructured inviscid method, in order to eventually assess S&C properties as early in the design process as possible. Specific results are presented regarding time, accuracy (as compared to a baseline wind tunnel database) and simplicity for the user. For COMSAC, it s more important to talk about the "specifications" required by Advanced Design and S&C, as well as how the CFD results can be combined for envelope evaluation.

  2. Performance Study and Dynamic Optimization Design for Thread Pool Systems

    SciTech Connect

    Dongping Xu

    2004-12-19

    Thread pools have been widely used by many multithreaded applications. However, the determination of the pool size according to the application behavior still remains problematic. To automate this process, in this thesis we have developed a set of performance metrics for quantitatively analyzing thread pool performance. For our experiments, we built a thread pool system which provides a general framework for thread pool research. Based on this simulation environment, we studied the performance impact brought by the thread pool on different multithreaded applications. Additionally, the correlations between internal characterizations of thread pools and their throughput were also examined. We then proposed and evaluated a heuristic algorithm to dynamically determine the optimal thread pool size. The simulation results show that this approach is effective in improving overall application performance.

  3. Design and Performance Evaluation of Sensors and Actuators for Advanced Optical Systems

    NASA Technical Reports Server (NTRS)

    Clark, Natalie

    2011-01-01

    Current state-of-the-art commercial sensors and actuators do not meet many of NASA s next generation spacecraft and instrument needs. Nor do they satisfy the DoD needs for satellite missions, especially micro/nano satellite missions. In an effort to develop advanced optical devices and instruments that meet mission requirements, NASA Langley recently completed construction of a new cleanroom housing equipment capable of fabricating high performance active optic and adaptive optic technologies including deformable mirrors, reconfigurable lenses (both refractive and diffractive), spectrometers, spectro-polarimeters, tunable filters and many other active optic devices. In addition to performance, these advanced optic technologies offer advantages in speed, size, weight, power consumption, and radiation tolerance. The active optic devices described in this paper rely on birefringent liquid crystal materials to alter either the phase or the polarization of the incoming light. Design considerations and performance evaluation results for various NASA applications are presented. Applications presented will include large space telescopes, optical communications, spacecraft windows, coronagraphs, and star trackers. Keywords: Photonics, Adaptive Optics, Tunable Filters, MEMs., MOEMs, Coronagraph, Star Tracker

  4. Design and performance evaluation of sensors and actuators for advanced optical systems

    NASA Astrophysics Data System (ADS)

    Clark, Natalie

    2011-04-01

    Current state-of-the-art commercial sensors and actuators do not meet many of NASA's next generation spacecraft and instrument needs. Nor do they satisfy the DoD needs for satellite missions, especially micro/nano satellite missions. In an effort to develop advanced optical devices and instruments that meet mission requirements, NASA Langley recently completed construction of a new cleanroom housing equipment capable of fabricating high performance active optic and adaptive optic technologies including deformable mirrors, reconfigurable lenses (both refractive and diffractive), spectrometers, spectro-polarimeters, tunable filters and many other active optic devices. In addition to performance, these advanced optic technologies offer advantages in speed, size, weight, power consumption, and radiation tolerance. The active optic devices described in this paper rely on birefringent liquid crystal materials to alter either the phase or the polarization of the incoming light. Design considerations and performance evaluation results for various NASA applications are presented. Applications presented will include large space telescopes, optical communications, spacecraft windows, coronagraphs, and star trackers.

  5. Design and performance of the ALS double-crystal monochromator

    SciTech Connect

    Jones, G.; Ryce, S.; Perera, R.C.C.

    1997-04-01

    A new {open_quotes}Cowan type{close_quotes} double-crystal monochromator, based on the boomerang design used at NSLS beamline X-24A, has been developed for beamline 9.3.1 at the ALS, a windowless UHV beamline covering the 1-6 keV photon-energy range. Beamline 9.3.1 is designed to simultaneously achieve the goals of high energy resolution, high flux, and high brightness at the sample. The mechanical design has been simplified, and recent developments in technology have been included. Measured mechanical precision of the monochromator shows significant improvement over existing designs. In tests with x-rays at NSLS beamline X-23 A2, maximum deviations in the intensity of monochromatic light were just 7% during scans of several hundred eV in the vicinity of the Cr K edge (6 keV) with the monochromator operating without intensity feedback. Such precision is essential because of the high brightness of the ALS radiation and the overall length of beamline 9.3.1 (26 m).

  6. The design of virtual signal analyzer with high cost performance

    NASA Astrophysics Data System (ADS)

    Wang, Ya-nan; Pei, Gui-ling; Xu, Lei

    2013-03-01

    Based on 16bit STEREO AUDIO CODEC and C# this paper introduces a virtual signal analyzer. It mainly describes the system's overall structure, hardware design, PC software framework, etc. With reducing costs dramatically, the system also achieves being a signal generator, oscilloscope, recorder, spectrum analyzer, time-frequency analyzer and so on.

  7. Infant ventilator design: performance during expiratory limb occlusion.

    PubMed

    Hall, M W; Peevy, K J

    1983-01-01

    We examined the specifications and design of the inspiratory pressure regulating valve of 8 continuous flow, pressure-limited infant ventilators. Two pressure regulating designs are currently available; one placing the primary pressure regulating valve on the inspiratory limb, the other placing it on the expiratory limb. Seven ventilators incorporate the latter design to limit inspiratory pressure and must have a safety pressure-relief valve located on the inspiratory limb to vent pressure in case of circuit occlusion. These pressure-relief valves are generally set by the manufacturer far in excess of pressures normally used for infant ventilation. Alarm systems are often absent or inadequate to warn of high pressure conditions during circuit obstruction. A case report detailing the fatal complication of prolonged excessive airway pressure during circuit occlusion is presented. Improvements in the pressure-relief valve designs currently available are possible, and may be necessary to provide adequate protection from barotrauma. The majority of infant ventilators currently available expose the patient to unnecessary excessive airway pressures in the case of expiratory limb occlusion, and the lack of alarm systems may leave the operator unaware of malfunction.

  8. Performance of Random Effects Model Estimators under Complex Sampling Designs

    ERIC Educational Resources Information Center

    Jia, Yue; Stokes, Lynne; Harris, Ian; Wang, Yan

    2011-01-01

    In this article, we consider estimation of parameters of random effects models from samples collected via complex multistage designs. Incorporation of sampling weights is one way to reduce estimation bias due to unequal probabilities of selection. Several weighting methods have been proposed in the literature for estimating the parameters of…

  9. Design and performance of the ALS double-crystal monochromator

    SciTech Connect

    Jones, G.; Ryce, S.; Perera, R.C.C.; Lindle, D.W. |; Karlin, B.A.; Woicik, J.C.

    1994-08-01

    A new ``Cowan type`` double-crystal monochromator, based on the boomerang design used at NSLS beamline X-24A, has been developed for beamline 9.3.1 at the ALS, a windowless UHV beamline covering the 1-6 keV photon-energy range. Beamline 9.3.1 is designed to simultaneously achieve the goals of high energy resolution, high flux, and high brightness at the sample. The mechanical design has been simplified, and recent developments in technology have been included. Measured mechanical precision of the monochromator shows significant improvement over existing designs. In tests with x-rays at NSLS beamline X-A, maximum deviations in the intensity of monochromatic light were just 7% during scans of several hundred eV in the vicinity of the Cr K edge (6 keV) with the monochromator operating without intensity feedback. Such precision is essential because of the high brightness of the ALS radiation and the overall length of beamline 9.3.1 (26 m).

  10. Safe, High-Performance, Sustainable Precast School Design

    ERIC Educational Resources Information Center

    Finsen, Peter I.

    2011-01-01

    School design utilizing integrated architectural and structural precast and prestressed concrete components has gained greater acceptance recently for numerous reasons, including increasingly sophisticated owners and improved learning environments based on material benefits such as: sustainability, energy efficiency, indoor air quality, storm…

  11. Research in the design of high-performance reconfigurable systems

    NASA Technical Reports Server (NTRS)

    Mcewan, S. D.; Spry, A. J.

    1985-01-01

    Computer aided design and computer aided manufacturing have the potential for greatly reducing the cost and lead time in the development of VLSI components. This potential paves the way for the design and fabrication of a wide variety of economically feasible high level functional units. It was observed that current computer systems have only a limited capacity to absorb new VLSI component types other than memory, microprocessors, and a relatively small number of other parts. The first purpose is to explore a system design which is capable of effectively incorporating a considerable number of VLSI part types and will both increase the speed of computation and reduce the attendant programming effort. A second purpose is to explore design techniques for VLSI parts which when incorporated by such a system will result in speeds and costs which are optimal. The proposed work may lay the groundwork for future efforts in the extensive simulation and measurements of the system's cost effectiveness and lead to prototype development.

  12. Design, Motivation and Performance in a Cooperative MOOC Course

    ERIC Educational Resources Information Center

    Castaño, Carlos; Maiz, Inmaculada; Garay, Urtza

    2015-01-01

    MOOCs are seen as the latest evolution in online learning and, since their launch in 2008, they have become an integral part of university course curricula. Despite the social success of these courses, the learning design and efficacy of their results have been questioned. Most current research has focused more on discussing their potential to…

  13. Evaluation and performance of an unconventional AFC-design

    SciTech Connect

    Schwartz, S.; Lindstroem, O.

    1996-12-31

    Alkaline fuel cells, AFC, now play a Cinderella role after their successes in space. There are signs that the {open_quotes}CO{sub 2} syndrome{close_quotes} at last will have its cure. The argument that removal of CO{sub 2} from air and hydrogen should be so expensive that AFC has to be ruled out for terrestrial applications is no longer true. Its low stack cost will be the decisive feature. The AFC could easily be developed to a mature, industrial product for a large number of applications. We and a few other groups have tried to keep the AFC technology alive in a hostile climate, preparing for a rebirth as happened to its notorious rival the PEFC. We have concentrated our efforts on two designs characterized by external or internal manifolding. Both designs rely on an electrolyte chamber giving a constant pressure between the gas space and the electrolyte over the whole electrode surface. Hoechst has developed another cell design for the same purpose. We shall here describe the design of such a module with external manifolding.

  14. Use and Rationale of Media Types in Performance-Centered Design.

    ERIC Educational Resources Information Center

    Schubert, Dave

    2002-01-01

    Focuses on the convergent rationale and use of media within performance centered design and how that can affect user performance using real-time electronic performance support system appliance design. Discusses the more effective time-based, interactive, and synchronized media types that have become viable with technological advancements.…

  15. 14 CFR 91.705 - Operations within airspace designated as Minimum Navigation Performance Specification Airspace.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Minimum Navigation Performance Specification Airspace. 91.705 Section 91.705 Aeronautics and Space FEDERAL... Operations within airspace designated as Minimum Navigation Performance Specification Airspace. (a) Except as... airspace designated as Minimum Navigation Performance Specifications airspace unless— (1) The aircraft...

  16. Design, Fabrication and Performance of Open Source Generation I and II Compliant Hydrodynamic Gas Foil Bearings

    NASA Technical Reports Server (NTRS)

    DellaCorte, Christopher; Radil, Kevin C.; Bruckner, Robert J.; Howard, S. Adam

    2007-01-01

    Foil gas bearings are self-acting hydrodynamic bearings made from sheet metal foils comprised of at least two layers. The innermost top foil layer traps a gas pressure film that supports a load while a layer or layers underneath provide an elastic foundation. Foil bearings are used in many lightly loaded, high-speed turbo-machines such as compressors used for aircraft pressurization, and small micro-turbines. Foil gas bearings provide a means to eliminate the oil system leading to reduced weight and enhanced temperature capability. The general lack of familiarity of the foil bearing design and manufacturing process has hindered their widespread dissemination. This paper reviews the publicly available literature to demonstrate the design, fabrication and performance testing of both first and second generation bump style foil bearings. It is anticipated that this paper may serve as an effective starting point for new development activities employing foil bearing technology.

  17. Active learning increases student performance in science, engineering, and mathematics.

    PubMed

    Freeman, Scott; Eddy, Sarah L; McDonough, Miles; Smith, Michelle K; Okoroafor, Nnadozie; Jordt, Hannah; Wenderoth, Mary Pat

    2014-06-10

    To test the hypothesis that lecturing maximizes learning and course performance, we metaanalyzed 225 studies that reported data on examination scores or failure rates when comparing student performance in undergraduate science, technology, engineering, and mathematics (STEM) courses under traditional lecturing versus active learning. The effect sizes indicate that on average, student performance on examinations and concept inventories increased by 0.47 SDs under active learning (n = 158 studies), and that the odds ratio for failing was 1.95 under traditional lecturing (n = 67 studies). These results indicate that average examination scores improved by about 6% in active learning sections, and that students in classes with traditional lecturing were 1.5 times more likely to fail than were students in classes with active learning. Heterogeneity analyses indicated that both results hold across the STEM disciplines, that active learning increases scores on concept inventories more than on course examinations, and that active learning appears effective across all class sizes--although the greatest effects are in small (n ≤ 50) classes. Trim and fill analyses and fail-safe n calculations suggest that the results are not due to publication bias. The results also appear robust to variation in the methodological rigor of the included studies, based on the quality of controls over student quality and instructor identity. This is the largest and most comprehensive metaanalysis of undergraduate STEM education published to date. The results raise questions about the continued use of traditional lecturing as a control in research studies, and support active learning as the preferred, empirically validated teaching practice in regular classrooms.

  18. Active learning increases student performance in science, engineering, and mathematics.

    PubMed

    Freeman, Scott; Eddy, Sarah L; McDonough, Miles; Smith, Michelle K; Okoroafor, Nnadozie; Jordt, Hannah; Wenderoth, Mary Pat

    2014-06-10

    To test the hypothesis that lecturing maximizes learning and course performance, we metaanalyzed 225 studies that reported data on examination scores or failure rates when comparing student performance in undergraduate science, technology, engineering, and mathematics (STEM) courses under traditional lecturing versus active learning. The effect sizes indicate that on average, student performance on examinations and concept inventories increased by 0.47 SDs under active learning (n = 158 studies), and that the odds ratio for failing was 1.95 under traditional lecturing (n = 67 studies). These results indicate that average examination scores improved by about 6% in active learning sections, and that students in classes with traditional lecturing were 1.5 times more likely to fail than were students in classes with active learning. Heterogeneity analyses indicated that both results hold across the STEM disciplines, that active learning increases scores on concept inventories more than on course examinations, and that active learning appears effective across all class sizes--although the greatest effects are in small (n ≤ 50) classes. Trim and fill analyses and fail-safe n calculations suggest that the results are not due to publication bias. The results also appear robust to variation in the methodological rigor of the included studies, based on the quality of controls over student quality and instructor identity. This is the largest and most comprehensive metaanalysis of undergraduate STEM education published to date. The results raise questions about the continued use of traditional lecturing as a control in research studies, and support active learning as the preferred, empirically validated teaching practice in regular classrooms. PMID:24821756

  19. Active learning increases student performance in science, engineering, and mathematics

    PubMed Central

    Freeman, Scott; Eddy, Sarah L.; McDonough, Miles; Smith, Michelle K.; Okoroafor, Nnadozie; Jordt, Hannah; Wenderoth, Mary Pat

    2014-01-01

    To test the hypothesis that lecturing maximizes learning and course performance, we metaanalyzed 225 studies that reported data on examination scores or failure rates when comparing student performance in undergraduate science, technology, engineering, and mathematics (STEM) courses under traditional lecturing versus active learning. The effect sizes indicate that on average, student performance on examinations and concept inventories increased by 0.47 SDs under active learning (n = 158 studies), and that the odds ratio for failing was 1.95 under traditional lecturing (n = 67 studies). These results indicate that average examination scores improved by about 6% in active learning sections, and that students in classes with traditional lecturing were 1.5 times more likely to fail than were students in classes with active learning. Heterogeneity analyses indicated that both results hold across the STEM disciplines, that active learning increases scores on concept inventories more than on course examinations, and that active learning appears effective across all class sizes—although the greatest effects are in small (n ≤ 50) classes. Trim and fill analyses and fail-safe n calculations suggest that the results are not due to publication bias. The results also appear robust to variation in the methodological rigor of the included studies, based on the quality of controls over student quality and instructor identity. This is the largest and most comprehensive metaanalysis of undergraduate STEM education published to date. The results raise questions about the continued use of traditional lecturing as a control in research studies, and support active learning as the preferred, empirically validated teaching practice in regular classrooms. PMID:24821756

  20. Wireless design of a multisensor system for physical activity monitoring.

    PubMed

    Mo, Lingfei; Liu, Shaopeng; Gao, Robert X; John, Dinesh; Staudenmayer, John W; Freedson, Patty S

    2012-11-01

    Real-time monitoring of human physical activity (PA) is important for assessing the intensity of activity and exposure to environmental pollutions. A wireless wearable multisenor integrated measurement system (WIMS) has been designed for real-time measurement of the energy expenditure and breathing volume of human subjects under free-living conditions. To address challenges posted by the limited battery life and data synchronization requirement among multiple sensors in the system, the ZigBee communication platform has been explored for energy-efficient design. Two algorithms have been developed (multiData packaging and slot-data-synchronization) and coded into a microcontroller (MCU)-based sensor circuitry for real-time control of wireless data communication. Experiments have shown that the design enables continued operation of the wearable system for up to 68 h, with the maximum error for data synchronization among the various sensor nodes (SNs) being less than 24 ms. Experiment under free-living conditions have shown that the WIMS is able to correctly recognize the activity intensity level 86% of the time. The results demonstrate the effectiveness of the energy-efficient wireless design for human PA monitoring.

  1. Aerodynamic Design Criteria for Class 8 Heavy Vehicles Trailer Base Devices to Attain Optimum Performance

    SciTech Connect

    Salari, K; Ortega, J

    2010-12-13

    Lawrence Livermore National Laboratory (LLNL) as part of its Department of Energy (DOE), Energy Efficiency and Renewable Energy (EERE), and Vehicle Technologies Program (VTP) effort has investigated class 8 tractor-trailer aerodynamics for many years. This effort has identified many drag producing flow structures around the heavy vehicles and also has designed and tested many new active and passive drag reduction techniques and concepts for significant on the road fuel economy improvements. As part of this effort a database of experimental, computational, and conceptual design for aerodynamic drag reduction devices has been established. The objective of this report is to provide design guidance for trailer base devices to improve their aerodynamic performance. These devices are commonly referred to as boattails, base flaps, tail devices, and etc. The information provided here is based on past research and our most recent full-scale experimental investigations in collaboration with Navistar Inc. Additional supporting data from LLNL/Navistar wind tunnel, track test, and on the road test will be published soon. The trailer base devices can be identified by 4 flat panels that are attached to the rear edges of the trailer base to form a closed cavity. These devices have been engineered in many different forms such as, inflatable and non-inflatable, 3 and 4-sided, closed and open cavity, and etc. The following is an in-depth discussion with some recommendations, based on existing data and current research activities, of changes that could be made to these devices to improve their aerodynamic performance. There are 6 primary factors that could influence the aerodynamic performance of trailer base devices: (1) Deflection angle; (2) Boattail length; (3) Sealing of edges and corners; (4) 3 versus 4-sided, Position of the 4th plate; (5) Boattail vertical extension, Skirt - boattail transition; and (6) Closed versus open cavity.

  2. New design deforming controlling system of the active stressed lap

    NASA Astrophysics Data System (ADS)

    Ying, Li; Wang, Daxing

    2008-07-01

    A 450mm diameter active stressed lap has been developed in NIAOT by 2003. We design a new lap in 2007. This paper puts on emphases on introducing the new deforming control system of the lap. Aiming at the control characteristic of the lap, a new kind of digital deforming controller is designed. The controller consists of 3 parts: computer signal disposing, motor driving and force sensor signal disposing. Intelligent numeral PID method is applied in the controller instead of traditional PID. In the end, the result of new deformation are given.

  3. Design and experiment performances of an inchworm type rotary actuator.

    PubMed

    Li, Jianping; Zhao, Hongwei; Shao, Mingkun; Zhou, Xiaoqin; Huang, Hu; Fan, Zunqiang

    2014-08-01

    A piezo-driven rotary actuator by means of inchworm principle is proposed in this paper. Six piezo-stacks and flexure hinges are used to realize large rotation ranges with high accuracy both in the forward and backward motions. Four right-angle flexure hinges and two right-circular flexure hinges are applied in the stator. The motion principle and theoretical analysis of the designed actuator are discussed. In order to investigate the working characteristics, a prototype actuator was manufactured and a series of experiment tests were carried out. The test results indicate that the maximum rotation velocity is 71,300 μrad/s; the maximum output torque is 19.6 N mm. The experiment results confirm that the designed actuator can obtain large rotation motion ranges with relatively high output torques and different rotation speeds on the condition of different driving voltages and frequencies.

  4. WMAP Observatory Thermal Design and On-Orbit Thermal Performance

    NASA Technical Reports Server (NTRS)

    Glazer, Stuart D.; Brown, Kimberly D.; Michalek, Theodore J.; Ancarrow, Walter C.

    2003-01-01

    The Wilkinson Microwave Anisotropy Probe (WMAP) observatory, launched June 30, 2001, is designed to measure the cosmic microwave background radiation with unprecedented precision and accuracy while orbiting the second Lagrange point (L2). The instrument cold stage must be cooled passively to <95K, and systematic thermal variations in selected instrument components controlled to less than 0.5 mK (rms) per spin period. This paper describes the thermal design and testing of the WMAP spacecraft and instrument. Flight thermal data for key spacecraft and instrument components are presented from launch through the first year of mission operations. Effects of solar flux variation due to the Earth's elliptical orbit about the sun, surface thermo-optical property degradations, and solar flares on instrument thermal stability are discussed.

  5. Laboratory design for high-performance electron microscopy

    SciTech Connect

    O'Keefe, Michael A.; Turner, John H.; Hetherington, Crispin J.D.; Cullis, A.G.; Carragher, Bridget; Jenkins, Ron; Milgrim, Julie; Milligan,Ronald A.; Potter, Clinton S.; Allard, Lawrence F.; Blom, Douglas A.; Degenhardt, Lynn; Sides, William H.

    2004-04-23

    Proliferation of electron microscopes with field emission guns, imaging filters and hardware spherical aberration correctors (giving higher spatial and energy resolution) has resulted in the need to construct special laboratories. As resolutions improve, transmission electron microscopes (TEMs) and scanning transmission electron microscopes (STEMs) become more sensitive to ambient conditions. State-of-the-art electron microscopes require state-of-the-art environments, and this means careful design and implementation of microscope sites, from the microscope room to the building that surrounds it. Laboratories have been constructed to house high-sensitive instruments with resolutions ranging down to sub-Angstrom levels; we present the various design philosophies used for some of these laboratories and our experiences with them. Four facilities are described: the National Center for Electron Microscopy OAM Laboratory at LBNL; the FEGTEM Facility at the University of Sheffield; the Center for Integrative Molecular Biosciences at TSRI; and the Advanced Microscopy Laboratory at ORNL.

  6. The design and performance of an improved target for MICE

    NASA Astrophysics Data System (ADS)

    Booth, C. N.; Hodgson, P.; Langlands, J.; Overton, E.; Robinson, M.; Smith, P. J.; Barber, G.; Long, K. R.; Shepherd, B.; Capocci, E.; MacWaters, C.; Tarrant, J.

    2016-05-01

    The linear motor driving the target for the Muon Ionisation Cooling Experiment has been redesigned to improve its reliability and performance. A new coil-winding technique is described which produces better magnetic alignment and improves heat transport out of the windings. Improved field-mapping has allowed the more precise construction to be demonstrated, and an enhanced controller exploits the full features of the hardware, enabling increased acceleration and precision. The new user interface is described and analysis of performance data to monitor friction is shown to allow quality control of bearings and a measure of the ageing of targets during use.

  7. Autonomous mine detection sensors (AMDS) design and performance

    NASA Astrophysics Data System (ADS)

    McCoy, Richard; DeGrano, Brian

    2005-06-01

    The Autonomous Mine Detection Sensor (AMDS) is a program to develop a suite of advanced sensor technology on a vehicular robot (PackBot). These sensors are characterized as having high detection performance and low false alarm rate. The AMDS program is sponsored by the U.S. Army CERDEC RDES Night Vision and Electronic Sensors Directorate (NVESD). The CyTerra Corporation solution to this problem is the combination of a Ground Penetration Radar (GPR) and a Metal Detector (MD) which comprise the AN/PSS-14. This paper presents the CyTerra Corporation concept and includes performance results from early government sponsored tests.

  8. Electrode design and performance of the ORNL positive ion sources

    SciTech Connect

    Whealton, J.H.; Gardner, W.L.; Haselton, H.H.

    1981-08-01

    The neutral beam development group at ORNL has designed, constructed, and shipped four 50-kV, 100-A sources to PPL to be used for neutral beam heating of the confined plasma on the PDX tokamak. These sources have higher current capability than scaled-down sources, and they are required to run for 0.5 s as opposed to the 0.3-s requirement for PLT and ISX-B sources. Due to an innovative electrode design, these higher power sources met these requirements and achieved a higher transmission efficiency - 76% of the total input power on target vs 60% for the original ISX-B and modified PLT sources or 40% for the original PLT sources. Using the same electrode design with a tetrode accelerating structure and a new, indirectly heated cathode, repeatable long pulse, high energy conditions of 70 kV, 7 A, 8 s, and 90 kV, 9 A, 5 s were achieved. Grid deformation calculations and Monte Carlo beam line gas deposition algorithms will be discussed. A direct-magnetic-electron-blocking, direct-recovery device is described, and theoretical considerations of it are discussed.

  9. KJRR-FAI Status Report of Conceptual Design Activities

    SciTech Connect

    N.E. Woolstenhulme; B.P. Nielson; D.B. Chapman; J.W. Nielsen; P.E. Murray; D.S. Crawford; S.D. Snow

    2013-12-01

    The Korea Atomic Energy Research Institute has initiated the Ki-Jang Research Reactor (KJRR) project to construct a new dedicated radio-isotope production facility in the KiJang province of South Korea. The KJRR will employ a uranium-molybdenum dispersion plate-type fuel clad in aluminum. The KJRR fuel assembly design will undergo irradiation in the Advanced Test Reactor (ATR) as part of the regulatory qualification of the fuel. The Idaho National Laboratory performed a multi-disciplined conceptual design effort and found that one full-size KJRR fuel assembly can be irradiated in the ATR’s north east flux trap. The analyses accomplished during the conceptual design phase are sufficient to prove viability of the overall design and irradiation campaign. Requirements for fission power can be met. The desired burnup can be achieved well within 15% depending on reactor operating availability. Mechanical design and structural analysis show that structural integrity of the irradiation test is maintained. It is recommended that future detailed design efforts be based on the concept described in this report.

  10. Sharing Collaborative Designs of Tobacco Cessation Performance Improvement CME Projects

    ERIC Educational Resources Information Center

    Mullikin, Elizabeth A.; Ales, Mary W.; Cho, Jane; Nelson, Teena M.; Rodrigues, Shelly B.; Speight, Mike

    2011-01-01

    Introduction: Performance Improvement Continuing Medical Education (PI CME) provides an important opportunity for CME providers to combine educational and quality health care improvement methodologies. Very few CME providers take on the challenges of planning this type of intervention because it is still a new practice and there are limited…

  11. Designing and Implementing Teacher Performance Management Systems: Pitfalls and Possibilities

    ERIC Educational Resources Information Center

    Wiener, Ross; Jacobs, Ariel

    2011-01-01

    As new performance-management-related policies go from idea to implementation, policy makers and education leaders will be called upon to flesh-out what are still broad principles in many areas. This represents a significant inflection point for the teaching profession and the management of public school systems. Early decisions will determine…

  12. Flight test and performance of a nongated active television system

    NASA Astrophysics Data System (ADS)

    Miller, John L.; Kelly, John M.; Ehlen, Jon

    1999-07-01

    A series of helicopter flight tests were conducted to test the feasibility and assess the performance of a gimbaled active television system and co-located IR system. The laser light was provided to the gimbal via a fiber optic cable from a remote semiconductor laser. A high power, divergent beam was used to illuminate a scene providing enhanced performance in poor weather, the recording of registry and augmentation to existing night vision devices. The flight tests were conducted in clear-weather conditions over land and water. Additionally, a series of ground test were conducted.

  13. APOLLO 9: Dave scott performs Extra Vehicular Activities

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Dave Scott performs Extra Vehicular Activities around the Command Module 'Gumdrop'. From the film documentary 'APOLLO 9: The Duet of Spider & Gumdrop': part of a documentary series made in the early 70's on the APOLLO missions, and narrated by Burgess Meredith. (Actual date created is not known at this time) Mission: APOLLO 9: Earth orbital flight with James A. McDivitt, David R. Scott, and Russell Schweickart. First flight of the Lunar Module. Performed rendezvous, docking and E.V.A..Mission Duration 241hrs 0m 54s.

  14. Instructional Design for Teaching Physical Activities: A Knowledge Structures Approach.

    ERIC Educational Resources Information Center

    Vickers, Joan N.

    This text uses the unique Knowledge Structures (KS) Model developed specifically for those who teach and coach complex physical skills. The KS Model provides the framework for constructing a sport-specific curriculum based on all of the pertinent information needed to perform a sport or activity. The model is cross-disciplinary, integrating…

  15. Short-term effects of integrated motor imagery practice on muscle activation and force performance.

    PubMed

    Di Rienzo, F; Blache, Y; Kanthack, T F D; Monteil, K; Collet, C; Guillot, A

    2015-10-01

    The effect of motor imagery (MI) practice on isometric force development is well-documented. However, whether practicing MI during rest periods of physical training improves the forthcoming performance remains unexplored. We involved 18 athletes in a counterbalanced design including three physical training sessions scheduled over five consecutive days. Training involved 10 maximal isometric contractions against a force plate, with the elbow at 90°. During two sessions, we integrated MI practice (focusing on either muscle activation or relaxation) during the inter-trial rest periods. We measured muscle performance from force plate and electromyograms of the biceps brachii and anterior deltoideus. We continuously monitored electrodermal activity (EDA) to control sympathetic nervous system activity. MI of muscle activation resulted in higher isometric force as compared to both MI of muscle relaxation and passive recovery (respectively +2.1% and +3.5%). MI practice of muscle relaxation also outperformed the control condition (+1.9%). Increased activation of the biceps brachii was recorded under both MI practice conditions compared to control. Biceps brachii activation was similar between the two MI practice conditions, but electromyography revealed a marginal trend toward greater activation of the anterior deltoideus during MI practice of muscle activation. EDA and self-reports indicated that these effects were independent from physiological arousal and motivation. These results might account for priming effects of MI practice yielding to higher muscle activation and force performance. Present findings may be of interest for applications in sports training and neurologic rehabilitation. PMID:26241339

  16. PERFORMANCE OF ACTIVATED SLUDGE-POWDERED ACTIVATED CARBON-WET AIR REGENERATION SYSTEMS

    EPA Science Inventory

    The investigation summarized in the report was undertaken to evaluate the performance of powdered activated carbon (PAC) technology used in conjunction with wet air regeneration (WAR) at municipal wastewater treatment plants. Excessive ash concentrations accumulated in the mixed ...

  17. The Effects of Goal Specificity and Scaffolding on Programming Performance and Self-Regulation in Game Design

    ERIC Educational Resources Information Center

    Feng, Chia-Yen; Chen, Ming-Puu

    2014-01-01

    The purpose of this study was to investigate the influence of goal specificity and scaffolding on the programming performance and self-regulation of elementary students engaged in learning game design. This study recruited 232 students for the experimental activities. Two levels of goal specificity were employed: specific and nonspecific.…

  18. The design and performance of the electromagnetic calorimeters in Hall C at Jefferson Lab

    SciTech Connect

    Vardan Tadevosyan, Hamlet Mkrtchyan, Arshak Asaturyan, Arthur Mkrtchyan, Simon Zhamkochyan

    2012-12-01

    The design and performance of the electromagnetic calorimeters in the magnetic spectrometers in Hall C at Jefferson Lab are presented. For the existing HMS and SOS spectrometers, construction information and comparisons of simulated and experimental results are presented. The design and simulated performance for a new calorimeter to be used in the new SHMS spectrometer is also presented. We have developed and constructed electromagnetic calorimeters from TF-1 type lead-glass blocks for the HMS and SOS magnetic spectrometers at JLab Hall C. The HMS/SOS calorimeters are of identical design and construction except for their total size. Blocks of dimension 10 cm × 10 cm × 70 cm are arranged in four planes and stacked 13 and 11 blocks high in the HMS and SOS respectively. The energy resolution of these calorimeters is better than 6%/√E, and pion/electron (π/e) separation of about 100:1 has been achieved in energy range 1–5 GeV. Good agreement has been observed between the experimental and GEANT4 simulated energy resolutions. The HMS/SOS calorimeters have been used nearly in all Hall C experiments, providing good energy resolution and a high pion suppression factor. No significant deterioration in their performance has been observed in the course of use since 1994. For the SHMS spectrometer, presently under construction, details on the calorimeter design and accompanying GEANT4 simulation efforts are given. A Preshower+Shower design was selected as the most cost-effective among several design choices. The preshower will consist of a layer of 28 modules with TF-1 type lead glass radiators, stacked in two columns. The shower part will consist of 224 modules with F-101 type lead glass radiators, stacked in a “fly's eye” configuration of 14 columns and 16 rows. The active area of 120 × 130 cm(2) will encompass the beam envelope at the calorimeter. The anticipated performance of the new calorimeter is simulated over the full momentum range of the SHMS, predicting

  19. Design for a Performance Based Adult Education Community Coordinating Agency.

    ERIC Educational Resources Information Center

    Stambler, Moses

    A plan is described for a project to establish an adult education coordinating and change agency in the New Haven, Connecticut area to coordinate activities of existing organizations; provide a research staff to establish a computerized data base; disseminate information and provide technological services to local agencies; set up a communications…

  20. Development of low-shock pyrotechnic separation nuts. [design performance of flight type nuts

    NASA Technical Reports Server (NTRS)

    Bement, L. J.; Neubert, V. H.

    1973-01-01

    Performance demonstrations and comparisons were made on six flight type pyrotechnic separation nut designs, two of which are standard designs in current use, and four of which were designed to produce low shock on actuation. Although the shock performances of the four low shock designs are considerably lower than the standard designs, some penalties may be incurred in increased volume, weight, or complexity. These nuts, and how they are installed, can significantly influence the pyrotechnic shock created in spacecraft structures. A high response monitoring system has been developed and demonstrated to provide accurate performance comparisons for pyrotechnic separation nuts.

  1. Designing an Energy Drink: High School Students Learn Design and Marketing Skills in This Activity

    ERIC Educational Resources Information Center

    Martin, Doug

    2008-01-01

    A decade ago, energy drinks were almost nonexistent in the United States, but in the past five years they've become wildly popular. In fact, the $3.4 billion energy-drink market is expected to double this year alone, and the younger generation is the market targeted by manufacturers. This article presents an energy-drink designing activity. This…

  2. Fashion Design: Designing a Learner-Active, Multi-Level High School Course

    ERIC Educational Resources Information Center

    Nelson, Diane

    2009-01-01

    A high school fashion design teacher has much in common with the ringmaster of a three-ring circus. The challenges of teaching a hands-on course are to facilitate the entire class and to meet the needs of individual students. When teaching family and consumer sciences, the goal is to have a learner-active classroom. Revamping the high school's…

  3. Performance Evaluation of a High Bandwidth Liquid Fuel Modulation Valve for Active Combustion Control

    NASA Technical Reports Server (NTRS)

    Saus, Joseph R.; DeLaat, John C.; Chang, Clarence T.; Vrnak, Daniel R.

    2012-01-01

    At the NASA Glenn Research Center, a characterization rig was designed and constructed for the purpose of evaluating high bandwidth liquid fuel modulation devices to determine their suitability for active combustion control research. Incorporated into the rig s design are features that approximate conditions similar to those that would be encountered by a candidate device if it were installed on an actual combustion research rig. The characterized dynamic performance measures obtained through testing in the rig are planned to be accurate indicators of expected performance in an actual combustion testing environment. To evaluate how well the characterization rig predicts fuel modulator dynamic performance, characterization rig data was compared with performance data for a fuel modulator candidate when the candidate was in operation during combustion testing. Specifically, the nominal and off-nominal performance data for a magnetostrictive-actuated proportional fuel modulation valve is described. Valve performance data were collected with the characterization rig configured to emulate two different combustion rig fuel feed systems. Fuel mass flows and pressures, fuel feed line lengths, and fuel injector orifice size was approximated in the characterization rig. Valve performance data were also collected with the valve modulating the fuel into the two combustor rigs. Comparison of the predicted and actual valve performance data show that when the valve is operated near its design condition the characterization rig can appropriately predict the installed performance of the valve. Improvements to the characterization rig and accompanying modeling activities are underway to more accurately predict performance, especially for the devices under development to modulate fuel into the much smaller fuel injectors anticipated in future lean-burning low-emissions aircraft engine combustors.

  4. UML activity diagram swimlanes in logic controller design

    NASA Astrophysics Data System (ADS)

    Grobelny, Michał; Grobelna, Iwona

    2015-12-01

    Logic controller behavior can be specified using various techniques, including UML activity diagrams and control Petri nets. Each technique has its advantages and disadvantages. Application of both specification types in one project allows to take benefits from both of them. Additional elements of UML models make it possible to divide a specification into some parts, considered from other point of view (logic controller, user or system). The paper introduces an idea to use UML activity diagrams with swimlanes to increase the understandability of design models.

  5. Ultra high resolution stepper motors design, development, performance and application

    NASA Technical Reports Server (NTRS)

    Moll, H.; Roeckl, G.

    1979-01-01

    The design and development of stepper motors with steps in the 10 arc sec to 2 arc min range is described. Some of the problem areas, e.g. rotor suspension, tribology aspects and environmental conditions are covered. A summary of achieved test results and the employment in different mechanisms already developed and tested is presented to give some examples of the possible use of this interesting device. Adaptations to military and commercial requirements are proposed and show the wide range of possible applications.

  6. Design and performance of the KSC Biomass Production Chamber

    NASA Technical Reports Server (NTRS)

    Prince, Ralph P.; Knott, William M.; Sager, John C.; Hilding, Suzanne E.

    1987-01-01

    NASA's Controlled Ecological Life Support System program has instituted the Kennedy Space Center 'breadboard' project of which the Biomass Production Chamber (BPC) presently discussed is a part. The BPC is based on a modified hypobaric test vessel; its design parameters and operational parameters have been chosen in order to meet a wide range of plant-growing objectives aboard future spacecraft on long-duration missions. A control and data acquisition subsystem is used to maintain a common link between the heating, ventilation, and air conditioning system, the illumination system, the gas-circulation system, and the nutrient delivery and monitoring subsystems.

  7. Status of nuclear light bulb engine design and performance analyses.

    NASA Technical Reports Server (NTRS)

    Bauer, H. E.

    1971-01-01

    The dynamic response is discussed of a nuclear light bulb engine to perturbations at full-power operating conditions, both with and without control systems. Start-up and shutdown procedures are described, along with the provisions for residual afterheat removal. Problems associated with uprated engine designs are examined. The results of some analytical studies indicate that satisfactory control can be obtained by varying the fuel injection rate by means of a control valve which responds to the rate of change of neutron flux, or to the difference between the instantaneous and steady-state neutron fluxes.

  8. Cost and performance of activated carbon injection for mercury control

    SciTech Connect

    2006-08-15

    Activated carbon injection (ACI) is one technology being developed to absorb mercury from mercury emitted from coal-fired power plants. In 2003/04, the USDOE and NETL selected 14 projects to test and evaluate mercury control technologies. While field testing is still ongoing, DOE/NETL recently completed an economic analysis of mercury control for six test sites spanning three ACI variations - conventional powdered activated carbon (PAC), brominated PAC and conventional PAC combined with a sorbent enhancement additive (SEA) applied to the coal. To evaluate the progress of the field testing program and discern the performance of ACI, a data adjustment methodology was developed to account for baseline methane capture. This data were used to perform economic analyses to achieve low, mid and high levels of mercury control. The costs are given in the article. Full details are available on the DOE/NETL website, www.netl.doe.gov. 2 figs., 1 photo.

  9. Engineering design activities and conceptual change in middle school science

    NASA Astrophysics Data System (ADS)

    Schnittka, Christine G.

    The purpose of this research was to investigate the impact of engineering design classroom activities on conceptual change in science, and on attitudes toward and knowledge about engineering. Students were given a situated learning context and a rationale for learning science in an active, inquiry-based method, and worked in small collaborative groups. One eighth-grade physical science teacher and her students participated in a unit on heat transfer and thermal energy. One class served as the control while two others received variations of an engineering design treatment. Data were gathered from teacher and student entrance and exit interviews, audio recordings of student dialog during group work, video recordings and observations of all classes, pre- and posttests on science content and engineering attitudes, and artifacts and all assignments completed by students. Qualitative and quantitative data were collected concurrently, but analysis took place in two phases. Qualitative data were analyzed in an ongoing manner so that the researcher could explore emerging theories and trends as the study progressed. These results were compared to and combined with the results of the quantitative data analysis. Analysis of the data was carried out in the interpretive framework of analytic induction. Findings indicated that students overwhelmingly possessed alternative conceptions about heat transfer, thermal energy, and engineering prior to the interventions. While all three classes made statistically significant gains in their knowledge about heat and energy, students in the engineering design class with the targeted demonstrations made the most significant gains over the other two other classes. Engineering attitudes changed significantly in the two classes that received the engineering design intervention. Implications from this study can inform teachers' use of engineering design activities in science classrooms. These implications are: (1) Alternative conceptions will

  10. Design and performance test of spacecraft test and operation software

    NASA Astrophysics Data System (ADS)

    Wang, Guohua; Cui, Yan; Wang, Shuo; Meng, Xiaofeng

    2011-06-01

    Main test processor (MTP) software is the key element of Electrical Ground Support Equipment (EGSE) for spacecraft test and operation used in the Chinese Academy of Space Technology (CAST) for years without innovation. With the increasing demand for a more efficient and agile MTP software, the new MTP software was developed. It adopts layered and plug-in based software architecture, whose core runtime server provides message queue management, share memory management and process management services and forms the framework for a configurable and open architecture system. To investigate the MTP software's performance, the test case of network response time, test sequence management capability and data-processing capability was introduced in detail. Test results show that the MTP software is common and has higher performance than the legacy one.

  11. A Standard Setting Method Designed for Complex Performance Assessments with Multiple Performance Categories: Categorical Assignments of Student Work.

    ERIC Educational Resources Information Center

    Plake, Barbara S.; Hambleton, Ronald K.

    This paper reports on a standard-setting method designed for complex performance assessments with multiple performance categories. The method studied, the Analytical Judgment Method, involves panelists' making analytical classification decisions for each of the test's components individually. It also allows for discussion and reconsideration of…

  12. Least cost process design for granular activated carbon adsorbers

    SciTech Connect

    Narbaitz, R.M.; Benedek, A.

    1983-10-01

    Although toxic organics may be removed from industrial effluents by activated carbon adsorbers, the cost of this process is relatively high. Also, adsorber design is complex because of the unsteady-state nature of the process and the numerous operational variables. A package of computer programs has been developed to help to minimise the ultimate cost of 4 types of column configurations. It determines the effect of treatment facility costs of different values for design and operational variables, such as empty bed contact time (EBCT), hydraulic loading, and column configurations. The results of a sample problem indicated that the optimum EBCT for all the column configurations was significantly higher than values typically used by designers.

  13. Alvord (3000-ft Strawn) LPG flood: design and performance evaluation

    SciTech Connect

    Frazier, G.D.; Todd, M.R.

    1982-01-01

    Mitchell Energy Corporation has implemented a LPG-dry gas miscible process in the Alvord (3000 ft Strawn) Unit in Wise County, Texas utilizing the DOE tertiary incentive program. The field had been waterflooded for 14 years and was producing near its economic limit at the time this project was started. This paper presents the results of the reservoir simulation study that was conducted to evaluate pattern configuration and operating alternatives so as to maximize LPG containment and oil recovery performance. Several recommendations resulting from this study were implemented for the project. Based on the model prediction, tertiary oil recovery is expected to be between 100,000 and 130,000 bbls, or about 7 percent of th oil originally in place in the Unit. An evaluation of the project performance to date is presented. In July of 1981 the injection of a 16% HPV slug of propane was completed. Natural gas is being used to drive the propane slug. A peak oil response of 222 BOPD was achieved in August of 1981 and production has since been declining. The observed performance of the flood indicates that the actual tertiary oil recovered will reach the predicted value, although the project life will be longer than expected. The results presented in this paper indicate that, without the DOE incentive program, the economics for this project would still be uncertain at this time.

  14. Style-independent document labeling: design and performance evaluation

    NASA Astrophysics Data System (ADS)

    Mao, Song; Kim, Jong Woo; Thoma, George R.

    2003-12-01

    The Medical Article Records System or MARS has been developed at the U.S. National Library of Medicine (NLM) for automated data entry of bibliographical information from medical journals into MEDLINE, the premier bibliographic citation database at NLM. Currently, a rule-based algorithm (called ZoneCzar) is used for labeling important bibliographical fields (title, author, affiliation, and abstract) on medical journal article page images. While rules have been created for medical journals with regular layout types, new rules have to be manually created for any input journals with arbitrary or new layout types. Therefore, it is of interest to label any journal articles independent of their layout styles. In this paper, we first describe a system (called ZoneMatch) for automated generation of crucial geometric and non-geometric features of important bibliographical fields based on string-matching and clustering techniques. The rule based algorithm is then modified to use these features to perform style-independent labeling. We then describe a performance evaluation method for quantitatively evaluating our algorithm and characterizing its error distributions. Experimental results show that the labeling performance of the rule-based algorithm is significantly improved when the generated features are used.

  15. Macroergonomic analysis and design for improved safety and quality performance.

    PubMed

    Kleiner, B M

    1999-01-01

    Macroergonomics, which emerged historically after sociotechnical systems theory, quality management, and ergonomics, is presented as the basis for a needed integrative methodology. A macroergonomics methodology was presented in some detail to demonstrate how aspects of microergonomics, total quality management (TQM), and sociotechnical systems (STS) can be triangulated in a common approach. In the context of this methodology, quality and safety were presented as 2 of several important performance criteria. To demonstrate aspects of the methodology, 2 case studies were summarized with safety and quality performance results where available. The first case manipulated both personnel and technical factors to achieve a "safety culture" at a nuclear site. The concept of safety culture is defined in INSAG-4 (International Atomic Energy Agency, 1991). as "that assembly of characteristics and attitudes in organizations and individuals which establishes that, as an overriding priority, nuclear plant safety issues receive the attention warranted by their significance." The second case described a tire manufacturing intervention to improve quality (as defined by Sink and Tuttle, 1989) through joint consideration of technical and social factors. It was suggested that macroergonomics can yield greater performance than can be achieved through ergonomic intervention alone. Whereas case studies help to make the case, more rigorous formative and summative research is needed to refine and validate the proposed methodology respectively.

  16. Aerodynamic performance of a 1.20-pressure ratio fan stage designed for low noise

    NASA Technical Reports Server (NTRS)

    Lewis, G. W., Jr.; Moore, R. D.

    1976-01-01

    The aerodynamic design and the overall blade element performance of a 51 centimeter diameter fan stage is presented. The stage was designed to minimize the noise generated by rotor stator interactions. The design pressure ratio was 1.20 at a flow of 30.6 kilograms per second and a rotor blade tip speed of 228.6 meters per second. At design speed the rotor peak efficiency was 0.935. The peak efficiency of the stage, however, was 0.824. The radial distribution of rotor performance parameters at peak efficiency and design speed indicated excellent agreement with design values.

  17. Impact of study design on development and evaluation of an activity-type classifier

    PubMed Central

    Golubic, Rajna; Ekelund, Ulf; Brage, Søren

    2013-01-01

    Methods to classify activity types are often evaluated with an experimental protocol involving prescribed physical activities under confined (laboratory) conditions, which may not reflect real-life conditions. The present study aims to evaluate how study design may impact on classifier performance in real life. Twenty-eight healthy participants (21–53 yr) were asked to wear nine triaxial accelerometers while performing 58 activity types selected to simulate activities in real life. For each sensor location, logistic classifiers were trained in subsets of up to 8 activities to distinguish between walking and nonwalking activities and were then evaluated in all 58 activities. Different weighting factors were used to convert the resulting confusion matrices into an estimation of the confusion matrix as would apply in the real-life setting by creating four different real-life scenarios, as well as one traditional laboratory scenario. The sensitivity of a classifier estimated with a traditional laboratory protocol is within the range of estimates derived from real-life scenarios for any body location. The specificity, however, was systematically overestimated by the traditional laboratory scenario. Walking time was systematically overestimated, except for lower back sensor data (range: 7–757%). In conclusion, classifier performance under confined conditions may not accurately reflect classifier performance in real life. Future studies that aim to evaluate activity classification methods are warranted to pay special attention to the representativeness of experimental conditions for real-life conditions. PMID:23429872

  18. Energy-Performance-Based Design-Build Process: Strategies for Procuring High-Performance Buildings on Typical Construction Budgets: Preprint

    SciTech Connect

    Scheib, J.; Pless, S.; Torcellini, P.

    2014-08-01

    NREL experienced a significant increase in employees and facilities on our 327-acre main campus in Golden, Colorado over the past five years. To support this growth, researchers developed and demonstrated a new building acquisition method that successfully integrates energy efficiency requirements into the design-build requests for proposals and contracts. We piloted this energy performance based design-build process with our first new construction project in 2008. We have since replicated and evolved the process for large office buildings, a smart grid research laboratory, a supercomputer, a parking structure, and a cafeteria. Each project incorporated aggressive efficiency strategies using contractual energy use requirements in the design-build contracts, all on typical construction budgets. We have found that when energy efficiency is a core project requirement as defined at the beginning of a project, innovative design-build teams can integrate the most cost effective and high performance efficiency strategies on typical construction budgets. When the design-build contract includes measurable energy requirements and is set up to incentivize design-build teams to focus on achieving high performance in actual operations, owners can now expect their facilities to perform. As NREL completed the new construction in 2013, we have documented our best practices in training materials and a how-to guide so that other owners and owner's representatives can replicate our successes and learn from our experiences in attaining market viable, world-class energy performance in the built environment.

  19. Total System Performance Assessment- License Appication Design Selection (LADS) Phase 1 Analysis for Post-Closure Ventilation (Design Alternative 3)

    SciTech Connect

    N. Erb

    1999-06-21

    The objective of this report is to evaluate the effect of potential changes to the TSPA-VA base case design on long-term repository performance. The design changes that are evaluated in this report include two configurations for post-closure ventilation. bow tie and open loop (Design Alternative 3 or D3). The following paragraphs briefly describe the motivation for evaluating post-closure ventilation. The bow tie configuration for post closure ventilation has been identified as a design alternative to the TSPA-VA base case model (CRWMS M&O, 1998a) that may provide improved performance by reducing the temperature and relative humidity within the waste package drifts. The bow tie configuration for post-closure ventilation is a closed-loop design. In this design. cross drifts are placed in pairs with each drift angling up on opposite sides of the repository. From the side, the cross drifts and side drifts form the shape of a bow tie. Movement of air through the system is driven by convective heating from the waste packages in the cross drifts. The open loop configuration is also being considered for its potential to improve post-closure performance of the repository. As with the bow tie configuration, the open loop is designed to decrease temperature and relative humidity within the waste package drifts. For the open loop configuration, air is drawn into the drifts from outside the mountain. The configuration for the repository with open-loop ventilation is similar to the base case repository design with a few added shafts to increase air flow through the drifts. This report documents the modeling assumptions and calculations conducted to evaluate the long-term performance of Design Alternative 3. The performance measure for this evaluation is dose rate. Results are presented that compare the dose-rate time histories with the new design alternatives to that for the TSPA-VA base case calculation (CRWMS M&O, 1998a).

  20. Theory and design of variable conductance heat pipes: Steady state and transient performance

    NASA Technical Reports Server (NTRS)

    Edwards, D. K.; Fleischman, G. L.; Marcus, B. D.

    1972-01-01

    Heat pipe technology pertinent to the design and application of self-controlled, variable conductance heat pipes for spacecraft thermal control is discussed. Investigations were conducted to: (1) provide additional confidence in existing design tools, (2) to generate new design tools, and (3) to develop superior variable conductance heat pipe designs. A computer program for designing and predicting the performance of the heat pipe systems was developed.

  1. Improved JPC performance via a low inductance, lumped element design

    NASA Astrophysics Data System (ADS)

    Narla, A.; Sliwa, K.; Hatridge, M.; Shankar, S.; Schackert, F.; Abdo, B.; Frunzio, L.; Schoelkopf, R. J.; Devoret, M. H.

    2013-03-01

    The Josephson Parametric Converter (JPC), a linear, non-degenerate, nearly quantum-limited amplifier, is a promising tool for quantum information applications. We propose a new JPC design characterized by the use of multi-pF parallel-plate capacitors. By decreasing the geometric inductance of the system, higher critical-current Josephson junctions can be used. Both the bandwidth and dynamic range can thus be increased by a factor of two relative to existing microstrip devices. When integrated with a shunted ring of Josephson junctions, these devices should also be tunable over more than a GHz. We present simulations of the circuit behavior and preliminary measurements of a proof-of-concept device. Work supported by: IARPA, ARO, and NSF

  2. Nondimensional Representations for Occulter Design and Performance Evaluation

    NASA Technical Reports Server (NTRS)

    Cady, Eric

    2011-01-01

    An occulter is a spacecraft with a precisely-shaped optical edges which ies in formation with a telescope, blocking light from a star while leaving light from nearby planets una ected. Using linear optimization, occulters can be designed for use with telescopes over a wide range of telescope aperture sizes, science bands, and starlight suppression levels. It can be shown that this optimization depends primarily on a small number of independent nondimensional parameters, which correspond to Fresnel numbers and physical scales and enter the optimization only as constraints. We show how these can be used to span the parameter space of possible optimized occulters; this data set can then be mined to determine occulter sizes for various mission scenarios and sets of engineering constraints.

  3. Smart wing shape memory alloy actuator design and performance

    NASA Astrophysics Data System (ADS)

    Jardine, A. Peter; Flanagan, John S.; Martin, Christopher A.; Carpenter, Bernie F.

    1997-05-01

    Shape Memory Effect TiNi torque tubes were fabricated, tested and installed to supply 2500 in.lbs and 500 in.lbs of torque for inboard and outboard sections, respectively, of the DARPA smart wing wind tunnel model. Structural connections to the tubes were designed so that the entire assembly would fit within the interior of the wing, whose maximum dimensions of depth ranged from 1.125' to 0.375', depending on the position along the wing span. The torque tubes themselves were made by the gun drilling a TiNi ingot and ElectroSpark Discharge Machining to the required dimensions, which were calculated from a simple model described in a previous paper. The torque tubes were placed into the wing and twist deflections were measured. Deflections on the wing were measured at 1.3 degree(s), which provided a significant increase (approximately 8%) in the wing rolling moment.

  4. NIRCam cryo filter wheel assembly design and performance

    NASA Astrophysics Data System (ADS)

    Clark, Charles S.; Privári, Béla I.

    2013-09-01

    The filter wheel assembly (FWA) is an integral and important sub-system of the Near Infrared Camera (NIRCam) instrument on the James Webb Space Telescope (JWST). The optic elements in each of the four FWA mechanisms on NIRCam are used to conduct science operations as well as calibration of the NIRCam instrument and the JWST observatory. The FWA mechanism can position one of 12 different filters in the optical path of the camera and position one of 12 different pupil optics in the same path. The filters and pupil optics are mounted in two separate wheel assemblies in the FWA that can be positioned independently to provide the desired optical configuration for imaging. Along with the rest of the instrument, the FWA operates at cryogenic temperatures and is used for both short and long wavelength imaging. This paper reviews significant elements of the FWA mechanism design.

  5. Design and performance of a robust WDM network

    NASA Astrophysics Data System (ADS)

    Vaishnav, Chintan H.; Nieberger, Matt; Jayasumana, Anura P.; Sauer, Jon R.

    1996-11-01

    Increasing number of bandwidth intensive applications demand introduction of concurrency among multiple user transmissions, using techniques such as time division multiplexing (TDM) or wavelength division multiplexing (WDM), to achieve higher aggregate bandwidth. Commercial exploitation of WDM networks, despite their immense potential and promise, find extreme reluctance due to their vulnerability to the wavelength instability of the transmitter sources, and budgetary concerns raised by the inordinate cost of stabilizing them. Robust WDM network uses an intelligent multichannel wavelength tracking receiver that is capable of dynamically accommodating the manufacturing and operating imperfections of the transmitter sources. This yields robust WDM to be a lucrative option for cost sensitive computer networking markets. In this paper we present token-based medium access control protocol and network node architecture designed for the demonstration testbed of robust WDM network. Behavior of average waiting time for a typical connection request on the network is presented using computer simulation.

  6. Design and Performance Estimates of an Ablative Gallium Electromagnetic Thruster

    NASA Technical Reports Server (NTRS)

    Thomas, Robert E.

    2012-01-01

    The present study details the high-power condensable propellant research being conducted at NASA Glenn Research Center. The gallium electromagnetic thruster is an ablative coaxial accelerator designed to operate at arc discharge currents in the range of 10-25 kA. The thruster is driven by a four-parallel line pulse forming network capable of producing a 250 microsec pulse with a 60 kA amplitude. A torsional-type thrust stand is used to measure the impulse of a coaxial GEM thruster. Tests are conducted in a vacuum chamber 1.5 m in diameter and 4.5 m long with a background pressure of 2 microtorr. Electromagnetic scaling calculations predict a thruster efficiency of 50% at a specific impulse of 2800 seconds.

  7. Performance studies of bulk Micromegas of different design parameters

    NASA Astrophysics Data System (ADS)

    Bhattacharya, P.; Bhattacharya, S.; Majumdar, N.; Mukhopadhyay, S.; Sarkar, S.; Colas, P.; Attie, D.

    2014-04-01

    The present work involves the comparison of various bulk Micromegas detectors having different design parameters. Six detectors with amplification gaps of 64,128,192,220μm and mesh hole pitch of 63,78μm were tested at room temperature and normal gas pressure. Two setups were built to evaluate the effect of the variation of the amplification gap and mesh hole pitch on different detector characteristics. The gain, energy resolution and electron transmission of these Micromegas detectors were measured in Argon-Isobutane (90:10) gas mixture while the measurements of the ion backflow were carried out in P10 gas. These measured characteristics have been compared in detail to numerical simulations using the Garfield framework that combines packages such as neBEM, Magboltz and Heed.

  8. Design and Performance of the Monopulse Control System

    NASA Astrophysics Data System (ADS)

    Gawronski, W.; Gudim, M. A.

    1999-01-01

    Ka-band (32-GHz) monopulse tracking has been chosen for the upcoming NASA missions. This decision requires an increased pointing accuracy of the Deep Space Network antenna servo systems that are maintained in a noisy environment. The noise sources include wind gusts, encoder imperfections, and Block V Receiver (BVR) noise. This article describes the selection of the position and monopulse controllers for the improved tracking accuracy and presents the results of the linear and nonlinear simulations to confirm that servo performance meets the requirements.

  9. Design and performance of TOPAZ TPC-trigger

    SciTech Connect

    Enomoto, R.; Tsukada, K.; Ujiie, N.; Shirahashi, A.

    1988-02-01

    The Time Projection Chamber (TPC) is widely used in the high energy physics experiment. The authors developed the new track finding algorithm by using the TOPAZ-TPC. The logic not only finds the number of tracks, but also calculates their vertex positions. It also takes care of the sector boundary crossing tracks. The proto-type TPC-Trigger has been tested at the in-beam experiment and has shown good performance. The authors achieved the vertex resolution of less than 10cm (r.m.s.) in the beam direction. The improved TPC-Trigger system is being used in October 1987 beam run.

  10. Design and performance analysis of gas sorption compressors

    NASA Technical Reports Server (NTRS)

    Chan, C. K.

    1984-01-01

    Compressor kinetics based on gas adsorption and desorption processes by charcoal and for gas absorption and desorption processes by LaNi5 were analyzed using a two-phase model and a three-component model, respectively. The assumption of the modeling involved thermal and mechanical equilibria between phases or among the components. The analyses predicted performance well for compressors which have heaters located outside the adsorbent or the absorbent bed. For the rapidly-cycled compressor, where the heater was centrally located, only the transient pressure compared well with the experimental data.

  11. High-performance pulsed magnets: Theory, design and construction

    NASA Astrophysics Data System (ADS)

    Li, Liang

    This thesis is an in-depth study of the design and construction of coils for pulsed magnets energised by a capacitor bank, including mathematical modelling and testing of the coils. The magnetic field generated by solenoid magnets with homogeneous and non-homogenous current distribution is calculated with the elliptical integral method. Coupled partial differential equations for magnetic and thermal diffusion and the electric circuits are solved numerically to calculate the pulse shape and the heating in a pulsed magnet. The calculations are in good agreement with test results for a large range of different coils; this provides useful insights for optimised coil design. Stresses and strains in the mid-plane of the coil are analytically calculated by solving the system of equations describing the displacement in each layer of the coil. Non-linear stress-strain characteristics and the propagation of the plastic deformation are taken into account by sub- dividing each layer of the coil in the radial direction and changing the elastic-plastic matrix at each transition point. Conductors, insulating materials and techniques used for pulsed magnets are discussed in detail. More than 80 pulsed magnets with optimised combinations of conductors and reinforcements have been built and tested, with peak fields in the range 45-73 T and a bore size from 8 mm-35 mm. The pulse duration is of the order of 10 milliseconds. A dual stage pulsed magnet for use at a free electron laser has been developed. This has a rise time of 10 microseconds and enables magneto-optical experiments in a parameter range previously inaccessible to condensed matter physicists. The joint of superconducting cables can be modelled by means of distributed circuit elements that characterise current diffusion.

  12. Encouraging overweight students with intellectual disability to actively perform walking activity using an air mouse combined with preferred stimulation.

    PubMed

    Chang, Chia-Jui; Chang, Man-Ling; Shih, Ching-Hsiang

    2016-08-01

    This study continues the research on using an air mouse as a physical activity detector. An air mouse is embedded with a MEMS (Micro Electro Mechanical Systems) gyro sensor, which can measure even the slightest movement in the air. The air mouse was strapped to one of each participant's calves to detect walking activity. This study was conducted to evaluate whether four students with intellectual disability who were overweight and disliked exercising could be motivated to engage in walking actively by linking the target response with preferred stimulation. Single-subject research with ABAB design was adopted in this study. The experimental data showed substantial increases in the participants' target responses (i.e. the performance of the activity of walking) during the intervention phases compared to the baseline phases. The practical and developmental implications of the findings are discussed. PMID:27037988

  13. Discovering a one-dimensional active subspace to quantify multidisciplinary uncertainty in satellite system design

    NASA Astrophysics Data System (ADS)

    Hu, Xingzhi; Parks, Geoffrey T.; Chen, Xiaoqian; Seshadri, Pranay

    2016-03-01

    Uncertainty quantification has recently been receiving much attention from aerospace engineering community. With ever-increasing requirements for robustness and reliability, it is crucial to quantify multidisciplinary uncertainty in satellite system design which dominates overall design direction and cost. However, coupled multi-disciplines and cross propagation hamper the efficiency and accuracy of high-dimensional uncertainty analysis. In this study, an uncertainty quantification methodology based on active subspaces is established for satellite conceptual design. The active subspace effectively reduces the dimension and measures the contributions of input uncertainties. A comprehensive characterization of associated uncertain factors is made and all subsystem models are built for uncertainty propagation. By integrating a system decoupling strategy, the multidisciplinary uncertainty effect is efficiently represented by a one-dimensional active subspace for each design. The identified active subspace is checked by bootstrap resampling for confidence intervals and verified by Monte Carlo propagation for the accuracy. To show the performance of active subspaces, 18 uncertainty parameters of an Earth observation small satellite are exemplified and then another 5 design uncertainties are incorporated. The uncertainties that contribute the most to satellite mass and total cost are ranked, and the quantification of high-dimensional uncertainty is achieved by a relatively small number of support samples. The methodology with considerably less cost exhibits high accuracy and strong adaptability, which provides a potential template to tackle multidisciplinary uncertainty in practical satellite systems.

  14. Affordable Design: A Methodolgy to Implement Process-Based Manufacturing Cost into the Traditional Performance-Focused Multidisciplinary Design Optimization

    NASA Technical Reports Server (NTRS)

    Bao, Han P.; Samareh, J. A.

    2000-01-01

    The primary objective of this paper is to demonstrate the use of process-based manufacturing and assembly cost models in a traditional performance-focused multidisciplinary design and optimization process. The use of automated cost-performance analysis is an enabling technology that could bring realistic processbased manufacturing and assembly cost into multidisciplinary design and optimization. In this paper, we present a new methodology for incorporating process costing into a standard multidisciplinary design optimization process. Material, manufacturing processes, and assembly processes costs then could be used as the objective function for the optimization method. A case study involving forty-six different configurations of a simple wing is presented, indicating that a design based on performance criteria alone may not necessarily be the most affordable as far as manufacturing and assembly cost is concerned.

  15. High-Performance Design Patterns for Modern Fortran

    DOE PAGES

    Haveraaen, Magne; Morris, Karla; Rouson, Damian; Radhakrishnan, Hari; Carson, Clayton

    2015-01-01

    This paper presents ideas for using coordinate-free numerics in modern Fortran to achieve code flexibility in the partial differential equation (PDE) domain. We also show how Fortran, over the last few decades, has changed to become a language well-suited for state-of-the-art software development. Fortran’s new coarray distributed data structure, the language’s class mechanism, and its side-effect-free, pure procedure capability provide the scaffolding on which we implement HPC software. These features empower compilers to organize parallel computations with efficient communication. We present some programming patterns that support asynchronous evaluation of expressions comprised of parallel operations on distributed data. We implemented thesemore » patterns using coarrays and the message passing interface (MPI). We compared the codes’ complexity and performance. The MPI code is much more complex and depends on external libraries. The MPI code on Cray hardware using the Cray compiler is 1.5–2 times faster than the coarray code on the same hardware. The Intel compiler implements coarrays atop Intel’s MPI library with the result apparently being 2–2.5 times slower than manually coded MPI despite exhibiting nearly linear scaling efficiency. As compilers mature and further improvements to coarrays comes in Fortran 2015, we expect this performance gap to narrow.« less

  16. Filter Design and Performance Evaluation for Fingerprint Image Segmentation.

    PubMed

    Thai, Duy Hoang; Huckemann, Stephan; Gottschlich, Carsten

    2016-01-01

    Fingerprint recognition plays an important role in many commercial applications and is used by millions of people every day, e.g. for unlocking mobile phones. Fingerprint image segmentation is typically the first processing step of most fingerprint algorithms and it divides an image into foreground, the region of interest, and background. Two types of error can occur during this step which both have a negative impact on the recognition performance: 'true' foreground can be labeled as background and features like minutiae can be lost, or conversely 'true' background can be misclassified as foreground and spurious features can be introduced. The contribution of this paper is threefold: firstly, we propose a novel factorized directional bandpass (FDB) segmentation method for texture extraction based on the directional Hilbert transform of a Butterworth bandpass (DHBB) filter interwoven with soft-thresholding. Secondly, we provide a manually marked ground truth segmentation for 10560 images as an evaluation benchmark. Thirdly, we conduct a systematic performance comparison between the FDB method and four of the most often cited fingerprint segmentation algorithms showing that the FDB segmentation method clearly outperforms these four widely used methods. The benchmark and the implementation of the FDB method are made publicly available.

  17. Filter Design and Performance Evaluation for Fingerprint Image Segmentation.

    PubMed

    Thai, Duy Hoang; Huckemann, Stephan; Gottschlich, Carsten

    2016-01-01

    Fingerprint recognition plays an important role in many commercial applications and is used by millions of people every day, e.g. for unlocking mobile phones. Fingerprint image segmentation is typically the first processing step of most fingerprint algorithms and it divides an image into foreground, the region of interest, and background. Two types of error can occur during this step which both have a negative impact on the recognition performance: 'true' foreground can be labeled as background and features like minutiae can be lost, or conversely 'true' background can be misclassified as foreground and spurious features can be introduced. The contribution of this paper is threefold: firstly, we propose a novel factorized directional bandpass (FDB) segmentation method for texture extraction based on the directional Hilbert transform of a Butterworth bandpass (DHBB) filter interwoven with soft-thresholding. Secondly, we provide a manually marked ground truth segmentation for 10560 images as an evaluation benchmark. Thirdly, we conduct a systematic performance comparison between the FDB method and four of the most often cited fingerprint segmentation algorithms showing that the FDB segmentation method clearly outperforms these four widely used methods. The benchmark and the implementation of the FDB method are made publicly available. PMID:27171150

  18. SKA Weak Lensing II: Simulated Performance and Survey Design Considerations

    NASA Astrophysics Data System (ADS)

    Bonaldi, Anna; Harrison, Ian; Camera, Stefano; Brown, Michael L.

    2016-08-01

    We construct a pipeline for simulating weak lensing cosmology surveys with the Square Kilometre Array (SKA), taking as inputs telescope sensitivity curves; correlated source flux, size and redshift distributions; a simple ionospheric model; source redshift and ellipticity measurement errors. We then use this simulation pipeline to optimise a 2-year weak lensing survey performed with the first deployment of the SKA (SKA1). Our assessments are based on the total signal-to-noise of the recovered shear power spectra, a metric that we find to correlate very well with a standard dark energy figure of merit. We first consider the choice of frequency band, trading off increases in number counts at lower frequencies against poorer resolution; our analysis strongly prefers the higher frequency Band 2 (950-1760 MHz) channel of the SKA-MID telescope to the lower frequency Band 1 (350-1050 MHz). Best results would be obtained by allowing the centre of Band 2 to shift towards lower frequency, around 1.1 GHz. We then move on to consider survey size, finding that an area of 5,000 square degrees is optimal for most SKA1 instrumental configurations. Finally, we forecast the performance of a weak lensing survey with the second deployment of the SKA. The increased survey size (3π steradian) and sensitivity improves both the signal-to-noise and the dark energy metrics by two orders of magnitude.

  19. Filter Design and Performance Evaluation for Fingerprint Image Segmentation

    PubMed Central

    Thai, Duy Hoang; Huckemann, Stephan; Gottschlich, Carsten

    2016-01-01

    Fingerprint recognition plays an important role in many commercial applications and is used by millions of people every day, e.g. for unlocking mobile phones. Fingerprint image segmentation is typically the first processing step of most fingerprint algorithms and it divides an image into foreground, the region of interest, and background. Two types of error can occur during this step which both have a negative impact on the recognition performance: ‘true’ foreground can be labeled as background and features like minutiae can be lost, or conversely ‘true’ background can be misclassified as foreground and spurious features can be introduced. The contribution of this paper is threefold: firstly, we propose a novel factorized directional bandpass (FDB) segmentation method for texture extraction based on the directional Hilbert transform of a Butterworth bandpass (DHBB) filter interwoven with soft-thresholding. Secondly, we provide a manually marked ground truth segmentation for 10560 images as an evaluation benchmark. Thirdly, we conduct a systematic performance comparison between the FDB method and four of the most often cited fingerprint segmentation algorithms showing that the FDB segmentation method clearly outperforms these four widely used methods. The benchmark and the implementation of the FDB method are made publicly available. PMID:27171150

  20. Piston designs keep pace with increased engine performance

    SciTech Connect

    Mullins, P.

    1996-12-01

    Piston technology for medium-speed diesel engines is having to keep pace with steadily increasing engine performance criteria. Specific output of medium-speed diesel engines has increased some 50% since 1970, according to Walter Griffiths, chief engineer at the UK-based AE Geotze Special Products Ltd. To satisfy the higher performance now required, a two-piece piston has been developed and went into production in 1995. This type still uses an aluminum alloy forged body, but incorporates a steel crown. The composite piston can carry higher engine ratings and resists the abrasive deposits formed by heavy fuel operation. It has become well established for bore sizes above 300 mm and is becoming increasingly specified for engines down to 200 mm. The latest solution to the carbon deposits on the top of the piston that has gained widespread acceptance within the industry is to reduce the diameter of the bore above the top ring and cut back the top land to maintain the normal operating clearance. This requires an insert to be fitted into the liner after the piston has been assembled. The effect is to limit the carbon build-up on the top land to a specific diameter, which is always less than the bore diameter. Thus there is no possibility of top land contact with the bore over the effective stroke of the piston rings. 2 figs.