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Sample records for actively perform designated

  1. Using Importance-Performance Analysis to Guide Instructional Design of Experiential Learning Activities

    ERIC Educational Resources Information Center

    Anderson, Sheri; Hsu, Yu-Chang; Kinney, Judy

    2016-01-01

    Designing experiential learning activities requires an instructor to think about what they want the students to learn. Using importance-performance analysis can assist with the instructional design of the activities. This exploratory study used importance-performance analysis in an online introduction to criminology course. There is limited…

  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. A modal H∞-norm-based performance requirement for damage-tolerant active controller design

    NASA Astrophysics Data System (ADS)

    Genari, Helói F. G.; Mechbal, Nazih; Coffignal, Gérard; Nóbrega, Eurípedes G. O.

    2017-04-01

    Damage-tolerant active control (DTAC) is a recent research area that encompasses control design methodologies resulting from the application of fault-tolerant control methods to vibration control of structures subject to damage. The possibility of damage occurrence is not usually considered in the active vibration control design requirements. Damage changes the structure dynamics, which may produce unexpected modal behavior of the closed-loop system, usually not anticipated by the controller design approaches. A modal H∞ norm and a respective robust controller design framework were recently introduced, and this method is here extended to face a new DTAC strategy implementation. Considering that damage affects each vibration mode differently, this paper adopts the modal H∞ norm to include damage as a design requirement. The basic idea is to create an appropriate energy distribution over the frequency range of interest and respective vibration modes, guaranteeing robustness, damage tolerance, and adequate overall performance, taking into account that it is common to have previous knowledge of the structure regions where damage may occur during its operational life. For this purpose, a structural health monitoring technique is applied to evaluate modal modifications caused by damage. This information is used to create modal weighing matrices, conducting to the modal H∞ controller design. Finite element models are adopted for a case study structure, including different damage severities, in order to validate the proposed control strategy. Results show the effectiveness of the proposed methodology with respect to damage tolerance.

  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.

    PubMed

    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 instructions by controlling their favorite environmental stimulation using Nintendo Wii Balance Boards. This study was carried out according to an A-B-A-B design. Data showed that both participants significantly increased their target response (performing a designated physical activity) by activating the control system to produce their preferred environmental stimulation during the intervention phases.

  8. 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…

  9. 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.

  10. 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.

  11. 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…

  12. 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…

  13. The influence of desk and display design on posture and muscle activity variability whilst performing information technology tasks.

    PubMed

    Straker, L; Burgess-Limerick, R; Pollock, C; Maslen, B

    2009-09-01

    Desk design and computer display height can affect posture and muscle activation during computer use. Amplitudes of postural variables and muscle activity during computer use do not explain the results from epidemiological studies of musculoskeletal discomfort and disorders related to computer use. The purpose of this study was to assess variability of posture and muscle activity during work with two computer display heights and book/paper, in conjunction with a curved desk designed to provide forearm support and a traditional, straight desk. 18 male and 18 female participants performed 10-min tasks involving keying, mousing, reading and writing in six desk/display conditions. 3D posture and surface emg were assessed for the final 2 min of each task. The curved desk resulted in greater postural and muscle activity variation, suggesting an advantage of this supportive surface over the straight desk. There was little difference in variability associated with the two display heights. However, greater variability of posture and muscle activity was evident with the book/paper condition. Non-touch typists had greater neck flexion variation. The design of information technology tasks and workstations can influence the short term variation in posture and muscle activity. Variation is influenced independently of mean postures and muscle amplitudes and therefore needs to be considered to adequately assess the risk of musculoskeletal disorders.

  14. 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

  15. 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.

  16. Interactive Design Activism

    NASA Astrophysics Data System (ADS)

    Goulev, Petar; Farrer, Joan

    The following sections are included: * Introduction * Computers and Human Well-being * To Fuzzy or Yes (No)! * Interactive Design Activism * Sensing the Sun * Personalised Public Health Advice * Modifying Human Behaviour * Transdisciplinarity, Knowledge Transfer and Multi-domain

  17. Airfoil Design and Rotorcraft Performance

    NASA Technical Reports Server (NTRS)

    Bousman, William G.

    2003-01-01

    The relationship between global performance of a typical helicopter and the airfoil environment, as represented by the airfoil angles of attack and Mach number, has been examined using the comprehensive analysis CAMRAD II. A general correspondence is observed between global performance parameters, such as rotor L/D, and airfoil performance parameters, such as airfoil L/D, the drag bucket boundaries, and the divergence Mach number. Effects of design parameters such as blade twist and rotor speed variation have been examined and, in most cases, improvements observed in global performance are also observed in terms of airfoil performance. The relations observed between global Performance and the airfoil environment suggests that the emphasis in airfoil design should be for good L/D, while the maximum lift coefficient performance is less important.

  18. Designing Metacognitive Activities.

    ERIC Educational Resources Information Center

    Lin, Xiaodong

    2001-01-01

    Proposes a framework for thinking about how metacognition research might apply to design activities. Examines two basic approaches to supporting metacognition: strategy training, and creation of a supportive social environment for metacognition. Identifies two kinds of content that are taught using these two approaches: knowledge about a specific…

  19. 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.

  20. Characterization, performance modeling, and design of an active capping remediation project in a heavily polluted urban channel.

    PubMed

    Yin, Ke; Viana, Priscilla; Zhao, Xiuhong; Rockne, Karl

    2010-07-15

    Collateral Channel is a heavily polluted former navigation slip to the Chicago Sanitary and Ship Canal (Illinois, USA). Characterization of sediment cores taken in the channel show high levels of heavy metals, polycyclic aromatic hydrocarbons (PAHs) and other contaminants in deposited sediment dating back to the 1800's. Of these, PAHs were the contaminants of greatest concern based upon exceedance of sediment contamination criteria (Sigma(16) PAHs up to 1500mg/kg). Benthic animal counts revealed a lack of biodiversity, with relatively low levels of small tubificid oligochaetes (generally <3000/m(2)) in surficial sediments. Comparison of surficial sediment contaminant levels between 1995 and 2005 showed few decreases in contaminant levels, indicating a lack of "natural recovery" processes occurring in the channel. These results led to an analysis of sediment amendments for an active capping demonstration project in the channel using transport models developed in our previous work (Viana et al., 2008). Based on the sediment characterization and modeling results, the active capping design will be focused on organic contaminant sequestration through the use of organoclay. A site-specific difficulty is the substantial rates of gas ebullition from anaerobic organic matter biodegradation in the sediments, particularly in the summer months. These gases can open advective channels that may result in substantial pollution release and compromise cap effectiveness, and thus the capping scenario must control for such releases. The active capping layer will underlay a sloped sand layer and a high permeability gas venting system to allow biogenically-produced gas migration to shoreline collectors through an innovative support grid. The cap will include an overlaying wetland to remove nutrients from the adjoining Chicago River and provide a public recreational space.

  1. Design and performance characterization of a hand orthosis prototype to aid activities of daily living in a post-stroke population.

    PubMed

    Gasser, Benjamin W; Goldfarb, Michael

    2015-01-01

    This paper presents the design of a hand orthosis prototype intended to assist persons with hand paresis, as a result of stroke, perform activities of daily living. Among its attributes, the orthosis is characterized by a low mass and small profile, while still offering the power assistance of a robotic exoskeleton. Experimental characterization of the orthosis is presented, including its mass, envelope dimensions, motion bandwidth, and joint torque characteristics.

  2. 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…

  3. 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.

  4. 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

  5. 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…

  6. 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.

  7. Designing high-performance jobs.

    PubMed

    Simons, Robert

    2005-01-01

    Tales of great strategies derailed by poor execution are all too common. That's because some organizations are designed to fail. For a company to achieve its potential, each employee's supply of organizational resources should equal the demand, and the same balance must apply to every business unit and to the company as a whole. To carry out his or her job, each employee has to know the answers to four basic questions: What resources do I control to accomplish my tasks? What measures will be used to evaluate my performance? Who do I need to interact with and influence to achieve my goals? And how much support can I expect when I reach out to others for help? The questions correspond to what the author calls the four basic spans of a job-control, accountability, influence, and support. Each span can be adjusted so that it is narrow or wide or somewhere in between. If you get the settings right, you can design a job in which a talented individual can successfully execute on your company's strategy. If you get the settings wrong, it will be difficult for an employee to be effective. The first step is to set the span of control to reflect the resources allocated to each position and unit that plays an important role in delivering customer value. This setting, like the others, is determined by how the business creates value for customers and differentiates its products and services. Next, you can dial in different levels of entrepreneurial behavior and creative tension by widening or narrowing spans of accountability and influence. Finally, you must adjust the span of support to ensure that the job or unit will get the informal help it needs.

  8. 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)

  9. Aircraft design optimization with multidisciplinary performance criteria

    NASA Technical Reports Server (NTRS)

    Morris, Stephen; Kroo, Ilan

    1989-01-01

    The method described here for aircraft design optimization with dynamic response considerations provides an inexpensive means of integrating dynamics into aircraft preliminary design. By defining a dynamic performance index that can be added to a conventional objective function, a designer can investigate the trade-off between performance and handling (as measured by the vehicle's unforced response). The procedure is formulated to permit the use of control system gains as design variables, but does not require full-state feedback. The examples discussed here show how such an approach can lead to significant improvements in the design as compared with the more common sequential design of system and control law.

  10. Neighborhood design and active aging.

    PubMed

    Michael, Yvonne L; Green, Mandy K; Farquhar, Stephanie A

    2006-12-01

    This qualitative analysis of focus groups describes how neighborhood design encourages active aging. Nine focus groups were conducted in 2002 and 2003 with residents (N=60) aged 55 and over living in Portland, OR, USA. Content analysis revealed that local shopping and services, traffic and pedestrian infrastructure, neighborhood attractiveness, and public transportation influence activity among older adults. This information will be useful for making policy recommendations relating to land use planning and transportation, to assist in senior-friendly developments and neighborhood improvements, and to design effective senior health interventions with an emphasis on neighborhood design influences.

  11. 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…

  12. ALMR plant design and performance

    SciTech Connect

    Kwant, W.; Boardman, C.E.; Dayal, Y.; Magee, P.M. )

    1992-01-01

    The advanced liquid-metal reactor (ALMR) plant, sponsored by the US Department of Energy and being developed by a General Electric Company lead industrial team, features simple and reliable safety systems, seismic isolation, passive decay heat removal, passive reactivity control, and substantial margins to structural and fuel damage limits during potential accident situations. These features will result in significant gains for public safety and protection of the owner's investment. Standardized modular construction and extensive factory fabrication will result in a plant design that is economically competitive. The reference commercial ALMR plant utilizes nine reactor modules arranged in three identical 480-MW(electric) power blocks for an overall plant net electrical rating of 1440 MW(electric). Each power block features three identical reactor modules, each with its own steam generator, that jointly supply power to a single turbine generator.

  13. Ion Propulsion Module design and mission performance

    NASA Technical Reports Server (NTRS)

    Graf, J. E.; Boain, R. J.; Pawlik, E. V.; Pless, L. C.

    1978-01-01

    This paper describes the design options, processes and tradeoffs that occur during the establishment of viable Ion Drive vehicle and mission designs. The options identify those internal vehicle design alternatives which are being considered for future Ion Drive missions, such as sunlight concentrating arrays and direct drive thrust subsystems, and their effect on mission performance. Also, the highly interactive nature of the Ion Drive design process, which occurs between the spacecraft and mission designers, is described. The results of design tradeoffs, performed for three Ion Drive comet rendezvous missions, are presented. These results include the following: (1) the power profile is determined primarily by the trajectory while second order effects include the solar cell characteristics and array concentration factor and degradation; and (2) the dominant parameter in mission performance determination, Ion Propulsion Module (IPM) mass, and IPM design, is the total cell power evaluated without concentration, at the beginning of life and at 1 AU.

  14. Planck payload module design and performance

    NASA Astrophysics Data System (ADS)

    Riti, Jean-Bernard; Dubruel, Denis; Nadarassin, Madivanane; Martin, Philippe P.; Gavila, Emmanuel; Lasic, Thierry; de Chambure, Daniel; Guillaume, Bernard

    2003-03-01

    Planck associated to Herschel is one of the next ESA scientific missions. Both satellites will be launched in 2007 on a single ARIANE V launcher to the 2nd Lagrange libration point L2. Planck is a Principal Investigator Survey mission and the Planck spacecraft will provide the environment for two full sky surveys in the frequency range from 30 to 857 GHz. Planck aims to image the temperature anisotropies of the Cosmic Microwave Background (CMB) over the whole sky with a sensitivity of ΔT/T = 2 .10-6 and an angular resolution of 10 arc-minutes. This will be obtained thanks to a wide wavelength range telescope associated to a cryogenic Payload Module. The Planck mission leads to very stringent requirements (straylight, thermal stability) that can only be achieved by designing the spacecraft at system level, combining optical, radio frequency and thermal engineering. The PLANCK Payload Module (PPLM) is composed of a cryo-structure supporting and a 1.5 m aperture off-axis telescope equipped of two scientific instruments HFI (High Frequency Instrument) and LFI (Low Frequency Instrument). The LFI detectors are based on HETM amplifier technology and need to be cooled down to 20 K. The detectors for the HFI are bolometers operating at 0.1 K. These temperature levels are obtained using 3 different active coolers, a 20K sorption cooler stage, which need pre-cooling stages for normal operation (the coldest one is around 60 K). Finally, the telescope temperature must be lower than 60 K. To meet those requirements, a specific cryo-structure accommodating a multi-stages cryogenic passive radiator has been developed. The design of this high efficiency radiator is basically a black painted open honeycomb surface radiatively insulated from the warm spacecraft by a set of angled shields opened towards cold space, also called "V-grooves". The coldest stage offers a ~1.5 W net cooling capacity around 55 K. Specific design are implemented to guarantee the straylight performance. The

  15. 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…

  16. Active Member Design, Modeling, and Verification

    NASA Technical Reports Server (NTRS)

    Umland, Jeffrey W.; Webster, Mark; John, Bruce

    1993-01-01

    The design and development of active members intended for use in structural control applications is presented. The use of three different solid state actuation materials, namely, piezoelectric, electrostictive, and magnetostrictive, is discussed. Test data is given in order to illustrate the actuator and device characteristics and performance.

  17. Passive Solar Construction--Design and Performance.

    ERIC Educational Resources Information Center

    Conservation and Renewable Energy Inquiry and Referral Service (DOE), Silver Spring, MD.

    Presented is a list of books and reports intended to serve as technical sources of information for the building professional interested in energy conservation. These publications are grouped under these headings: (1) energy-conserving building design; (2) passive systems/design; (3) passive systems/performance; and (4) proceedings (of the American…

  18. 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.

  19. 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

  20. Thermic diode performance characteristics and design manual

    NASA Technical Reports Server (NTRS)

    Bernard, D. E.; Buckley, S.

    1979-01-01

    Thermic diode solar panels are a passive method of space and hot water heating using the thermosyphon principle. Simplified methods of sizing and performing economic analyses of solar heating systems had until now been limited to passive systems. A mathematical model of the thermic diode including its high level of stratification has been constructed allowing its performance characteristics to be studied. Further analysis resulted in a thermic diode design manual based on the f-chart method.

  1. 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.

  2. 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

  3. Advanced photovoltaic solar array - Design and performance

    NASA Technical Reports Server (NTRS)

    Kurland, Richard; Stella, Paul

    1992-01-01

    This paper reports on the development of an ultralightweight flexible blanket, flatpack, foldout solar array design that can provide 3- to 4-fold improvement on specific power performance of current rigid panel arrays and a factor of two improvement over a first-generation flexible blanket array developed as a forerunner to the Space Station Freedom array. To date a prototype wing has been built with a projected specific power performance of about 138 W/kg at beginning-of-life (BOL) and 93 W/kg end-of-life (EOL) at 12 kW (BOL) for a 10-year geosynchronous (GEO) mission. The prototype wing hardware has been subjected to a series of system-level tests to demonstrate design feasibility. The design of the array is summarized. The major trade studies that led to the selection of the baseline design are discussed. Key system-level and component-level testing are described. Array-level performance projections are presented as a function of existing and advanced solar array component technology for various mission applications.

  4. 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.

  5. Assisting Design Given Multiple Performance Criteria

    DTIC Science & Technology

    1988-08-01

    by mapping an equational description of a common signal processing computation into a recurrence relation. The relationships between the input and...the plot, since 5 these transformations change the plot’s orientation and shape. They result in new tim- ing relationships , different numbers of...characteristics of the design to the system. The problem with this approach is the performance specifications are completely divorced from what is

  6. 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.

  7. Assessing Design Activity in Complex CMOS Circuit Design.

    ERIC Educational Resources Information Center

    Biswas, Gautam; And Others

    This report characterizes human problem solving in digital circuit design. Protocols of 11 different designers with varying degrees of training were analyzed by identifying the designers' problem solving strategies and discussing activity patterns that differentiate the designers. These methods are proposed as a tentative basis for assessing…

  8. Experiences performing conceptual design optimization of transport aircraft

    NASA Technical Reports Server (NTRS)

    Arbuckle, P. D.; Sliwa, S. M.

    1984-01-01

    Optimum Preliminary Design of Transports (OPDOT) is a computer program developed at NASA Langley Research Center for evaluating the impact of new technologies upon transport aircraft. For example, it provides the capability to look at configurations which have been resized to take advantage of active controls and provide and indication of economic sensitivity to its use. Although this tool returns a conceptual design configuration as its output, it does not have the accuracy, in absolute terms, to yield satisfactory point designs for immediate use by aircraft manufacturers. However, the relative accuracy of comparing OPDOT-generated configurations while varying technological assumptions has been demonstrated to be highly reliable. Hence, OPDOT is a useful tool for ascertaining the synergistic benefits of active controls, composite structures, improved engine efficiencies and other advanced technological developments. The approach used by OPDOT is a direct numerical optimization of an economic performance index. A set of independent design variables is iterated, given a set of design constants and data. The design variables include wing geometry, tail geometry, fuselage size, and engine size. This iteration continues until the optimum performance index is found which satisfies all the constraint functions. The analyst interacts with OPDOT by varying the input parameters to either the constraint functions or the design constants. Note that the optimization of aircraft geometry parameters is equivalent to finding the ideal aircraft size, but with more degrees of freedom than classical design procedures will allow.

  9. 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.

  10. The design of high-performance gliders

    NASA Technical Reports Server (NTRS)

    Mueller, B.; Heuermann, V.

    1985-01-01

    A high-performance glider is defined as a glider which has been designed to carry the pilot in a minimum of time a given distance, taking into account conditions which are as conveniently as possible. The present investigation has the objective to show approaches for enhancing the cross-country flight cruising speed, giving attention to the difficulties which the design engineer will have to overcome. The characteristics of the cross-country flight and their relation to the cruising speed are discussed, and a description is provided of mathematical expressions concerning the cruising speed, the sinking speed, and the optimum gliding speed. The effect of aspect ratio and wing loading on the cruising speed is illustrated with the aid of a graph. Trends in glider development are explored, taking into consideration the design of laminar profiles, the reduction of profile-related drag by plain flaps, and the variation of wing loading during the flight. A number of suggestions are made for obtaining gliders with improved performance.

  11. 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.

  12. 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.

  13. 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…

  14. 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.

  15. 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.

  16. Design and performance of subgrade biogeochemical reactors.

    PubMed

    Gamlin, Jeff; Downey, Doug; Shearer, Brad; Favara, Paul

    2017-02-18

    Subgrade biogeochemical reactors (SBGRs), also commonly referred to as in situ bioreactors, are a unique technology for treatment of contaminant source areas and groundwater plume hot spots. SBGRs have most commonly been configured for enhanced reductive dechlorination (ERD) applications for chlorinated solvent treatment. However, they have also been designed for other contaminant classes using alternative treatment media. The SBGR technology typically consists of removal of contaminated soil via excavation or large-diameter augers, and backfill of the soil void with gravel and treatment amendments tailored to the target contaminant(s). In most cases SBGRs include installation of infiltration piping and a low-flow pumping system (typically solar-powered) to recirculate contaminated groundwater through the SBGR for treatment. SBGRs have been constructed in multiple configurations, including designs capable of meeting limited access restrictions at heavily industrialized sites, and at sites with restrictions on surface disturbance due to sensitive species or habitat issues. Typical performance results for ERD applications include 85 to 90 percent total molar reduction of chlorinated volatile organic compounds (CVOCs) near the SBGR and rapid clean-up of adjacent dissolved contaminant source areas. Based on a review of the literature and CH2M's field-scale results from over a dozen SBGRs with a least one year of performance data, important site-specific design considerations include: 1) hydraulic residence time should be long enough for sufficient treatment but not too long to create depressed pH and stagnant conditions (e.g., typically between 10 and 60 days), 2) reactor material should balance appropriate organic mulch as optimal bacterial growth media along with other organic additives that provide bioavailable organic carbon, 3) a variety of native bacteria are important to the treatment process, and 4) biologically mediated generation of iron sulfides along with

  17. 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 curl-ups.…

  18. Automated Assistance for Designing Active Magnetic Bearings

    NASA Technical Reports Server (NTRS)

    Imlach, Joseph

    2008-01-01

    MagBear12 is a computer code that assists in the design of radial, heteropolar active magnetic bearings (AMBs). MagBear12 was developed to help in designing the system described in "Advanced Active-Magnetic-Bearing Thrust-Measurement System". Beyond this initial application, MagBear12 is expected to be useful for designing AMBs for a variety of rotating machinery. This program incorporates design rules and governing equations that are also implemented in other, proprietary design software used by AMB manufacturers. In addition, this program incorporates an advanced unpublished fringing-magnetic-field model that increases accuracy beyond that offered by the other AMB-design software.

  19. 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

  20. AVIRIS scan drive design and performance

    NASA Technical Reports Server (NTRS)

    Miller, D. C.

    1987-01-01

    The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) images the ground with an instantaneous field of view (IFOV) of 1 mrad. The IFOV is scanned 30 deg from left to right to provide the cross-track dimension of the image, while the aircraft's motion provides the along-track dimension. The scanning frequency is 12 Hz, with a scan efficiency of 70 percent. The scan mirror has an effective diameter of 5.7 in, and its positional accuracy is a small fraction of a milliradian of the nominal position-time profile. Described are the design and performance of the scan drive mechanism. Tradeoffs among various approaches are discussed, and the reasons given for the selection of the cam drive.

  1. Tools for active control system design

    NASA Technical Reports Server (NTRS)

    Adams, W. M., Jr.; Tiffany, S. H.; Newsom, J. R.

    1984-01-01

    Efficient control law analysis and design tools which properly account for the interaction of flexible structures, unsteady aerodynamics and active controls are developed. Development, application, validation and documentation of efficient multidisciplinary computer programs for analysis and design of active control laws are also discussed.

  2. 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…

  3. VIRUS-P: camera design and performance

    NASA Astrophysics Data System (ADS)

    Tufts, Joseph R.; MacQueen, Phillip J.; Smith, Michael P.; Segura, Pedro R.; Hill, Gary J.; Edmonston, Robert D.

    2008-07-01

    We present the design and performance of the prototype Visible Integral-field Replicable Unit Spectrograph (VIRUS-P) camera. Commissioned in 2007, VIRUS-P is the prototype for 150+ identical fiber-fed integral field spectrographs for the Hobby-Eberly Telescope Dark Energy Experiment. With minimal complexity, the gimbal mounted, double-Schmidt design achieves high on-sky throughput, image quality, contrast, and stability with novel optics, coatings, baffling, and minimization of obscuration. The system corrector working for both the collimator and f / 1.33 vacuum Schmidt camera serves as the cryostat window while a 49 mm square aspheric field flattener sets the central obscuration. The mount, electronics, and cooling of the 2k × 2k, Fairchild Imaging CCD3041-BI fit in the field-flattener footprint. Ultra-black knife edge baffles at the corrector, spider, and adjustable mirror, and a detector mask, match the optical footprints at each location and help maximize the 94% contrast between 245 spectra. An optimally stiff and light symmetric four vane stainless steel spider supports the CCD which is thermally isolated with an equally stiff Ultem-1000 structure. The detector/field flattener spacing is maintained to 1 μm for all camera orientations and repeatably reassembled to 12 μm. Invar rods in tension hold the camera focus to +/-4 μm over a -5-25 °C temperature range. Delivering a read noise of 4.2 e- RMS, sCTE of 1-10-5 , and pCTE of 1-10-6 at 100 kpix/s, the McDonald V2 controller also helps to achieve a 38 hr hold time with 3 L of LN2 while maintaining the detector temperature setpoint to 150 μK (5σ RMS).

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. Designing Real-Life Cases To Support Authentic Design Activities.

    ERIC Educational Resources Information Center

    Bennett, Sue; Harper, Barry; Hedberg, John

    Teachers in a range of disciplines are interested in engaging their students in authentic activities that reflect the experiences of real-world practitioners. Adopting this approach requires the design and implementation of learning environments that incorporate and support such activities. This paper describes two real-life cases at the…

  9. STACEE-32: Design, performance, and preliminary results

    NASA Astrophysics Data System (ADS)

    Ong, Rene A.

    2000-06-01

    The Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE) is designed to detect astrophysical sources of γ-rays at energies between 25 and 500 GeV. STACEE uses large solar mirrors (heliostats) to collect the atmospheric Cherenkov radiation produced in γ-ray air showers. The use of a large mirror collection area will allow STACEE to probe γ-ray sources at energies above the reach of the Compton Gamma Ray Observatory (CGRO), but below the reach of conventional Cherenkov telescopes. During the 1998-99 observing season, a portion of STACEE using 32 heliostats was installed at the National Solar Thermal Test Facility (NSTTF) of Sandia National Laboratories (Albuquerque, NM). This initial configuration (STACEE-32) observed a number of astronomical sources, including the Crab and several active galactic nuclei (AGN). Here we report on these observations. We highlight the experimental configuration and the preliminary results from the Crab data. The full STACEE experiment using 64 heliostats will be commissioned in 2000. .

  10. 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.

  11. Wireless Body Area Network (WBAN) design techniques and performance evaluation.

    PubMed

    Khan, Jamil Yusuf; Yuce, Mehmet R; Bulger, Garrick; Harding, Benjamin

    2012-06-01

    In recent years interest in the application of Wireless Body Area Network (WBAN) for patient monitoring applications has grown significantly. A WBAN can be used to develop patient monitoring systems which offer flexibility to medical staff and mobility to patients. Patients monitoring could involve a range of activities including data collection from various body sensors for storage and diagnosis, transmitting data to remote medical databases, and controlling medical appliances, etc. Also, WBANs could operate in an interconnected mode to enable remote patient monitoring using telehealth/e-health applications. A WBAN can also be used to monitor athletes' performance and assist them in training activities. For such applications it is very important that a WBAN collects and transmits data reliably, and in a timely manner to a monitoring entity. In order to address these issues, this paper presents WBAN design techniques for medical applications. We examine the WBAN design issues with particular emphasis on the design of MAC protocols and power consumption profiles of WBAN. Some simulation results are presented to further illustrate the performances of various WBAN design techniques.

  12. 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.

  13. 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.

  14. 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.

  15. 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.…

  16. 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

  17. 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.

  18. Design optimization of system level adaptive optical performance

    NASA Astrophysics Data System (ADS)

    Michels, Gregory J.; Genberg, Victor L.; Doyle, Keith B.; Bisson, Gary R.

    2005-09-01

    By linking predictive methods from multiple engineering disciplines, engineers are able to compute more meaningful predictions of a product's performance. By coupling mechanical and optical predictive techniques mechanical design can be performed to optimize optical performance. This paper demonstrates how mechanical design optimization using system level optical performance can be used in the development of the design of a high precision adaptive optical telescope. While mechanical design parameters are treated as the design variables, the objective function is taken to be the adaptively corrected optical imaging performance of an orbiting two-mirror telescope.

  19. 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...

  20. 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...

  1. 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…

  2. Physical activity helps to control music performance anxiety.

    PubMed

    Rocha, Sérgio F; Marocolo, Moacir; Corrêa, Elisangela N V; Morato, Gledys S G; da Mota, Gustavo R

    2014-06-01

    We evaluated if regular physical activity could influence musical performance anxiety (MPA) in college music students. Levels of MPA, as measured with the Kenny MPA Inventory, and a survey about the physical activity habits were obtained from 87 students of music. The results showed that physically active musicians had lower MPA scores (p<0.05) than non-active ones, independent of gender. We conclude that there is an association between physical activity and minor MPA, and studies with a longitudinal design should be done to explore this important issue.

  3. 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.

  4. 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…

  5. 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.

  6. New design of high performance ionizing bar

    NASA Astrophysics Data System (ADS)

    Wang, Ronggang; Sun, Yurong

    2013-03-01

    This paper introduces a new design of DC-pulse ionizing bar to solve the problem of imbalance offset voltage for the AC ionizing bar, which is easily affected by the environment, as well as indicate the final tests. The new design mainly includes five parts: power supply circuit, main control unit, logic circuit, high frequency transformer unit, and feedback unit. The ionizing bar can automatically adjust the discharge voltage, pulse frequency and pulse width to balance the positive and negative ions. The final test results indicate that the DC ionizing bar owns good effect in electrostatic elimination.

  7. JLEIC forward detector design and performance

    SciTech Connect

    Yoshida, Rikutaro

    2016-11-01

    A major part of the physics program at the Electron-Ion Collider being planned in the US is the exploration of nucleon and nuclear structure. This program means that detection of particles that move in the forward direction and are associated with the beam electrons and protons(ions) is an important part of the detector design as well as of the accelerator and interaction area designs. The current planning of the forward detection for the Jefferson Lab Electron-Ion Collider is discussed.

  8. 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.

  9. 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…

  10. 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…

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. Design and analysis of thrust active magnetic bearing

    NASA Astrophysics Data System (ADS)

    Jang, Seok-Myeong; Lee, Un-Ho; Choi, Jang-Young; Hong, Jung-Pyo

    2008-04-01

    This paper deals with the design and analysis of thrust active magnetic bearing (AMB). Using the analytical solutions for thrust, resistance, and inductance obtained from equivalent magnetic circuits method, we determine initial design parameters such as the size of magnetic circuit, coil diameter, and the number of turns by investigating the variation of thrust according to design parameters. Then, using nonlinear finite element analysis, a detailed design considering saturation is performed in order to meet required thrust under restricted conditions. Finally, by confirming that the design result is shown in good agreement with experimental results, the validity of design procedures for thrust AMB used in this paper is proved. In particular, the dynamic test results of the thrust AMB are also given to confirm the validity of the design.

  17. 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.

  18. 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…

  19. Design for the Maintainer: Projecting Maintenance Performance from Design Characteristics.

    DTIC Science & Technology

    1981-07-01

    come from experimentally produced changes in the micro-elements. Several projects have employed time synthesis simulation with generally positive ...would produce, positions the video tape unit to the segment showing that outcome, and plays the taped segment showing a technician performing the test and... Psycological Services, Inc. Massachusetts Institute of Technolgy 404 East Lancaster Street Cembridge, MA 02139 Wayne, PA 19087 Dr. Harry Snyder 1 Dr. W. S

  20. 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.

  1. 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.

  2. Dawn Maneuver Design Performance at Vesta

    NASA Technical Reports Server (NTRS)

    Parcher, D. W.; Abrahamson, M.; Ardito, A.; Han, D.; Haw, R. J.; Kennedy, B. M.; Mastrodemos, N.; Nandi, S.; Park, R. S.; Rush, B. P.; Smith, B. A.; Smith, J. C.; Vaughan, A. T.; Whiffen, G. J.

    2013-01-01

    The Dawn spacecraft orbited the asteroid Vesta from July 16, 2011 to September 5, 2012, successfully accomplishing the four planned science orbits and two planned rotational characterization orbits. The lowest-altitude science orbit lasted four months, with 20 planned orbit maintenance maneuvers. Navigation results from Vesta demonstrate that the navigation plan was sufficient to achieve orbit delivery accuracy requirements. This paper compares the flown Dawn trajectory against the planned trajectory and expected maneuver dispersions. Understanding the effectiveness of the Vesta maneuver design plan is a key component of planning for operations at Ceres, the next destination for the Dawn mission.

  3. 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.

  4. Diffraction performance calculations in lens design.

    NASA Astrophysics Data System (ADS)

    Malacara, D.

    A review of the methods employed to compute the wavefront shape, the point spread function and the optical transfer function in lens evaluation programs is presented. One of the simplest methods to perform numerical calculations of the diffraction performance of optical systems is to divide the aperture in small squares, and then to consider the wavefront in each of these small squares to be flat and perpendicular to the ray direction in that region. This method however, presents some limitations, since the wavefront has to be flat within a fraction of the wavelength in that small square. This might not be the case if the wavefront is either too aberrated, or the defocusing is too large.

  5. 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.

  6. Active fragments-guided drug discovery and design of selective tropane alkaloids using ultra-high performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry coupled with virtual calculation and biological evaluation.

    PubMed

    Zhou, Mengge; Ma, Xiaoyao; Sun, Jixue; Ding, Guoyu; Cui, Qingxin; Miao, Yan; Hou, Yuanyuan; Jiang, Min; Bai, Gang

    2017-02-01

    Tropane alkaloids (TAs), rich in the plant of Physochlaina infundibularis Kuang, which is named Huashanshen (HSS) in China, showed good effects on types of spasms. However, no data were collected to explore the relationship between the specificity for muscarinic receptor subtypes and the structures of these TAs. To address this issue, an extracted ion chromatogram (EIC) strategy using ultra-high performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-Q/TOF-MS) based on the fragmentation behavior of the TA standards was established to rapidly capture the varied TAs from HSS. Based on the provided structural information of diagnostic ions or neutral loss, 29 TAs were efficiently profiled, especially some trace ingredients. In additional, via virtual validation combined with molecular dynamic simulation, approximately a dozen alkaloids were found with high selectivity for muscarinic receptors. In additional, N-acetyl convolicine was chosen for selectivity evaluation of M2 or M3 receptors through the use of a dual-luciferase reporter assay system at the cellular level and an ACh-induced constricted strip test in vitro. After summarizing the active fragments and the structure-activity relationship (SAR) information, a new modified TA that takes advantage of both the high affinity and high selectivity for M3 receptors was proposed and evaluated successfully. This study provided an effective approach for the discovery and design of natural products based on highly selective drugs by UPLC-Q/TOF-MS coupled with virtual calculation and biological evaluation. Graphical Abstract Active fragments-guided strategy for selective inhibitors from HSS.

  7. ACCESS: thermal mechanical design and performance

    NASA Astrophysics Data System (ADS)

    Kaiser, Mary E.; Morris, Matthew J.; Hansen, Jason; Jensen, Scott; McCandliss, Stephan R.; Rauscher, Bernard J.; Kimble, Randy A.; Kruk, Jeffrey W.; Pelton, Russell; Mott, D. Brent; Wen, Yiting; Gardner, Jonathan P.; Benford, Dominic J.; Woodgate, Bruce E.; Wright, Edward L.; Feldman, Paul D.; Moos, H. Warren; Riess, Adam G.; Bohlin, Ralph; Deustua, Susana E.; Dixon, W. V.; Sahnow, David J.; Kurucz, Robert; Lampton, Michael; Perlmutter, Saul

    2013-09-01

    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 0.35-1.7μm bandpass. Achieving a calibration accuracy of 1% not only requires an accurate calibration transfer from the detector standards to the instrument, but it also requires characterization and stability of the detector as well as a thermal background that contributes less than 1% to the flux per resolution element in the near-infrared (1.7μm) spectral region of the ACCESS bandpass. This paper describes the thermal mechanical design for achieving a low thermal background across the ACCESS spectral bandpass.

  8. Quadratic performance index generation for optimal regular design.

    NASA Technical Reports Server (NTRS)

    Bullock, T. E.; Elder, J. M.

    1971-01-01

    Application of optimal control theory to practical problems has been limited by the difficulty of prescribing a performance index which accurately reflects design requirements. The task of deriving equivalent performance indices is considered in the present paper for a plant that is a completely controllable, scalar linear system with state feedback. A quadratic index is developed which leads to an optimal design performance satisfying some of the classical performance criteria.

  9. Off-design performance analysis of MHD generator channels

    NASA Astrophysics Data System (ADS)

    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.

  10. DESIGN OF MEDICAL RADIOMETER FRONT-END FOR IMPROVED PERFORMANCE.

    PubMed

    Klemetsen, O; Birkelund, Y; Jacobsen, S K; Maccarini, P F; Stauffer, P R

    2011-01-01

    We have investigated the possibility of building a singleband Dicke radiometer that is inexpensive, small-sized, stable, highly sensitive, and which consists of readily available microwave components. The selected frequency band is at 3.25-3.75 GHz which provides a reasonable compromise between spatial resolution (antenna size) and sensing depth for radiometry applications in lossy tissue. Foreseen applications of the instrument are non-invasive temperature monitoring for breast cancer detection and temperature monitoring during heating. We have found off-the-shelf microwave components that are sufficiently small (< 5 mm × 5 mm) and which offer satisfactory overall sensitivity. Two different Dicke radiometers have been realized: one is a conventional design with the Dicke switch at the front-end to select either the antenna or noise reference channels for amplification. The second design places a matched pair of low noise amplifiers in front of the Dicke switch to reduce system noise figure.Numerical simulations were performed to test the design concepts before building prototype PCB front-end layouts of the radiometer. Both designs provide an overall power gain of approximately 50 dB over a 500 MHz bandwidth centered at 3.5 GHz. No stability problems were observed despite using triple-cascaded amplifier configurations to boost the thermal signals. The prototypes were tested for sensitivity after calibration in two different water baths. Experiments showed superior sensitivity (36% higher) when implementing the low noise amplifier before the Dicke switch (close to the antenna) compared to the other design with the Dicke switch in front. Radiometer performance was also tested in a multilayered phantom during alternating heating and radiometric reading. Empirical tests showed that for the configuration with Dicke switch first, the switch had to be locked in the reference position during application of microwave heating to avoid damage to the active components

  11. 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.

  12. 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.

  13. FAST Spacecraft Battery Design and Performance

    NASA Technical Reports Server (NTRS)

    Jung, David S.; Rao, Gopalakrishna; Ahmad, Anisa

    1997-01-01

    The Fast Auroral Snapshot (FAST) Explorer spacecraft is to study the physical processes that produce the aurora borealis and aurora australis. It is a unique plasma physics experiment that will take fundamental measurements of the magnetic and electrical fields. This investigation will add significantly to our understanding of the near-earth space environments and its effect. The FAST has a 1 year requirement and 3-year goal for its mission life in low earth orbit. The FAST power power system topology is a Direct Energy Transfer (DET) system based on the SAMPEX design. The FAST flight battery supplies power to the satellite during pre-launch operations, the launch phase, the eclipse periods for all mission phases, and when the load is about 50 watts.

  14. 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.

  15. Acoustical pipe lagging systems design and performance

    SciTech Connect

    Stevens, R.D.; Chapnik, B.V.; Howe, B.

    1998-10-30

    HGC Engineering was retained by the PRC International at the American Gas Association, to undertake a study of acoustical pipe lagging systems. The study included gathering input from PRCI member companies regarding their concerns and their established material specifications for lagging systems; conducting a comprehensive acoustical measurement program; using the measured results in conjunction with computer modeling to identify optimal lagging configurations; and developing material specifications for several standardized lagging systems for use by PRCI member companies. For all the lagging configurations, the measurement and modeling results showed amplification of sound at frequencies less than about 315 Hz. This result is a well known phenomenon, widely discussed the published acoustical literature, which means that pipe lagging is only effective for controlling higher frequencies noise (above about 500 Hz). Fortunately, in many gas piping applications, it is this higher frequency range that is of concern. The measurement and modeling results further showed that the high frequency performance of a lagging system is dependent primarily on having sufficient jacket mass and insulation thickness. The performance can be improved using an intermediate mass loaded barrier layer.

  16. 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.

  17. Design of a programmable active acoustics metamaterial

    NASA Astrophysics Data System (ADS)

    Smoker, Jason J.

    Metamaterials are artificial materials engineered to provide properties which may not be readily available in nature. The development of such class of materials constitutes a new area of research that has grown significantly over the past decade. Acoustic metamaterials, specifically, are even more novel than their electromagnetic counterparts arising only in the latter half of the decade. Acoustic metamaterials provide a new tool in controlling the propagation of pressure waves. However, physical design and frequency tuning, is still a large obstacle when creating a new acoustic metamaterial. This dissertation describes active and programmable design for acoustic metamaterials which allows the same basic physical design principles to be used for a variety of application. With cloaking technology being of a great interest to the US Navy, the proposed design approach would enable the development of a metamaterial with spatially changing effective parameters while retaining a uniform physical design features. The effective parameters would be controlled by tuning smart actuators embedded inside the metamaterial structure. Since this design is based on dynamic effective parameters that can be electrically controlled, material property ranges of several orders of magnitude could potentially be achieved without changing any physical parameters. With such unique capabilities, physically realizable acoustic cloaks can be achieved and objects treated with these active metamaterials can become acoustically invisible.

  18. 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.

  19. 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.

  20. Optoelectronic retinal prosthesis: system design and performance.

    PubMed

    Loudin, J D; Simanovskii, D M; Vijayraghavan, K; Sramek, C K; Butterwick, A F; Huie, P; McLean, G Y; Palanker, D V

    2007-03-01

    The design of high-resolution retinal prostheses presents many unique engineering and biological challenges. Ever smaller electrodes must inject enough charge to stimulate nerve cells, within electrochemically safe voltage limits. Stimulation sites should be placed within an electrode diameter from the target cells to prevent 'blurring' and minimize current. Signals must be delivered wirelessly from an external source to a large number of electrodes, and visual information should, ideally, maintain its natural link to eye movements. Finally, a good system must have a wide range of stimulation currents, external control of image processing and the option of either anodic-first or cathodic-first pulses. This paper discusses these challenges and presents solutions to them for a system based on a photodiode array implant. Video frames are processed and imaged onto the retinal implant by a head-mounted near-to-eye projection system operating at near-infrared wavelengths. Photodiodes convert light into pulsed electric current, with charge injection maximized by applying a common biphasic bias waveform. The resulting prosthesis will provide stimulation with a frame rate of up to 50 Hz in a central 10 degrees visual field, with a full 30 degrees field accessible via eye movements. Pixel sizes are scalable from 100 to 25 microm, corresponding to 640-10,000 pixels on an implant 3 mm in diameter.

  1. Pointing control system design and performance evaluation of TPF coronagraph

    NASA Astrophysics Data System (ADS)

    Liu, Kuo-Chia; Blaurock, Carl; Mosier, Gary E.

    2004-09-01

    The Terrestrial Planet Finder (TPF) project aims to detect and characterize extra-solar Earth-like planets. The coronagraph telescope is one of the two mission concepts being studied. To reject the star flux and detect the planet flux in the visible light range, the coronagraph telescope must achieve a rejection ratio on the order of a billion to one. Dynamic jitter, introduced by environmental and on-board mechanical disturbances, degrades the optical performance, as characterized primarily by contrast ratio. The feasibility of using passive vibration isolation combined with active attitude and line-of-sight (LOS) control systems to stabilize the spacecraft and the optical components to the requisite level is being studied. The telescope is also required to slew between targets or rotate around the LOS. The slew mode control law must be designed to balance the need for efficient large-angle maneuvers while simultaneously avoiding the excitation of flexible modes in order to minimize settling time. This paper provides an overview of the current control design concept and sensor/actuator topology for TPF Coronagraph and illustrates the fine pointing performance of the telescope. This performance is primarily a function of the rejection of high-frequency dynamic disturbances, in this case due to reaction wheel disturbance forces/torques transmitted through the passive isolation stage. Trade studies between isolator force rejection and disturbance level reduction via wheel redesign are also presented to illustrate the requirements imposed on current technologies. Finally, the paper summarizes preliminary results on the slew/settle performance of the telescope.

  2. 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.

  3. 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.

  4. Research on design multi-points performance curves of pump

    NASA Astrophysics Data System (ADS)

    Li, L.; Li, H.; Xu, D. H.

    2012-11-01

    The centrifugal pump's performance curves are the most important chart to reveal relevance of different performance parameters. They can show pump's function comprehensively and graphically. However these curves can't be predicted and designed precisely, duo to the complicated flow inside the impeller and the incomplete way to design pump. The complete shape of performance curves can be gained only after test. With the development of industry, many applications need the pump operating well at different flow conditions. It means the pump's performance curves should pass some specific points. This is a problem to the designer who still uses the traditional way to design pumps. In this paper, the Design of experiments was applied to arrange a plan of experiments. Because the theory equations of performance curves contain many geometry factors of impeller, changing these factors have different influence on the shape of curves, the relationship between geometry factors and the performance under different operation points been attained after using variance analysis to deal with experiment data. The relevant regression models and graphs were drawn to help understand these relationships. Depending on the predicted values of geometry factors pump's impeller was redesigned, and the pump's performance been simulated for saving time and cost. Test shows that the shape of performance curves satisfy design objective, this example can be taken as a reference of pump's specific designs.

  5. Pointing Control System Design and Performance Evaluation for TPF Coronagraph

    NASA Technical Reports Server (NTRS)

    Liu, Kuo-Chia; Blaurock, Carl; Mosier, Gary

    2004-01-01

    The Terrestrial Planet Finder (TPF) program aims to detect and characterize extra-solar Earth-like planets. The coronagraph telescope is one of the four mission concepts being studied. In order to reject the star flux and detect the planet flux in the visible light range, the coronagraph telescope must achieve a rejection ratio on the order of a billion to one. Dynamic jitter, introduced by environmental and on-board mechanical disturbances, degrades the optical performance, as characterized primarily by contrast ratio. The feasibility of using passive vibration isolation combined with active attitude and line-of- sight control systems to stabilize the spacecraft and the optical components to the requisite level is being studied. The telescope is also required to slew between targets. The slew mode control law must be designed to balance the need for efficient large-angle maneuvers while simultaneously avoiding the excitation of flexible modes in order to minimize settling time.

  6. 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.

  7. Development and final design of FAME active array

    NASA Astrophysics Data System (ADS)

    Farkas, Szigfrid; Agócs, Tibor; Aitink-Kroes, Gabby; Bettonvil, Felix; Black, Martin; Hugot, Emmanuel; Jaskó, Attila; Miller, Chris; Schnetler, Hermine; van Duffelen, Farian; Venema, Lars

    2016-07-01

    FAME (Freeform Active Mirror Experiment - part of the FP7 OPTICON/FP7 development programme) intends to demonstrate the huge potential of active mirrors and freeform optical surfaces. Freeform active surfaces can help to address the new challenges of next generation astronomical instruments, which are bigger, more complex and have tighter specifications than their predecessors. The FAME design consists of a pre-formed, deformable thin mirror sheet with an active support system. The thin face sheet provides a close to final surface shape with very high surface quality. The active array provides the support, and through actuation, the control to achieve final surface shape accuracy. In this paper the development path, trade-offs and demonstrator design of the FAME active array is presented. The key step in the development process of the active array is the design of the mechanical structure and especially the optimization of the actuation node positions, where the actuator force is transmitted to the thin mirror sheet. This is crucial for the final performance of the mirror where the aim is to achieve an accurate surface shape, with low residual (high order) errors using the minimum number of actuators. These activities are based on the coupling of optical and mechanical engineering, using analytical and numerical methods, which results in an active array with optimized node positions and surface shape.

  8. Design and Performance Analysis of Incremental Networked Predictive Control Systems.

    PubMed

    Pang, Zhong-Hua; Liu, Guo-Ping; Zhou, Donghua

    2016-06-01

    This paper is concerned with the design and performance analysis of networked control systems with network-induced delay, packet disorder, and packet dropout. Based on the incremental form of the plant input-output model and an incremental error feedback control strategy, an incremental networked predictive control (INPC) scheme is proposed to actively compensate for the round-trip time delay resulting from the above communication constraints. The output tracking performance and closed-loop stability of the resulting INPC system are considered for two cases: 1) plant-model match case and 2) plant-model mismatch case. For the former case, the INPC system can achieve the same output tracking performance and closed-loop stability as those of the corresponding local control system. For the latter case, a sufficient condition for the stability of the closed-loop INPC system is derived using the switched system theory. Furthermore, for both cases, the INPC system can achieve a zero steady-state output tracking error for step commands. Finally, both numerical simulations and practical experiments on an Internet-based servo motor system illustrate the effectiveness of the proposed method.

  9. Design and performance evaluation of a dual bell nozzle

    NASA Astrophysics Data System (ADS)

    Kbab, H.; Sellam, M.; Hamitouche, T.; Bergheul, S.; Lagab, L.

    2017-01-01

    The main objective of a dual bell nozzle is the enhancement of performances based on the principle of auto-adaptation in accordance with the altitude. Indeed, this system has as advantage the auto-adaptation of the flow for two operating modes (at low and high altitude) without mechanical activation. The principle is theoretically simple but structural forces involved can be significant. In this study, a numerical method for the design of this type of nozzle is developed. On the one hand, it is based on a transonic flow approaches to define the starting line on which the supersonic calculations will be initiated. On the other hand, the method of characteristics is used to draw the base nozzle profile. Knowing that the latter is assimilated as a polynomial of the second degree, its constants are calculated from initial conditions. In order to minimize the weight of this nozzle, its truncation proves necessary; this is performed at a point where the best compromise (weight / performances) was respected. The profile of the second curve is calculated to give a constant wall pressure. This is achieved by using the direct method of characteristics applied for a centered expansion wave that the intensity is P2/P1 at the junction. Once the profile is generated, an analysis of the thermodynamic-parameters evolution (such as: pressure, Mach number) and aerodynamic performances is conducted. For more consistency, our results are compared with numerical databases of ONERA nozzle. Simulations of flow in the nozzle with Ansys 13.0 environment for different types of meshes are presented. Also, to offset the effects of the boundary layer, the simulations were performed by using the k-ω SST turbulence model. The obtained results by the method of characteristics and numerical simulation are compared to the computed results of the literature and it was found good agreement and similarity.

  10. 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).

  11. 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.

  12. Modeling and design of a high-performance hybrid actuator

    NASA Astrophysics Data System (ADS)

    Aloufi, Badr; Behdinan, Kamran; Zu, Jean

    2016-12-01

    This paper presents the model and design of a novel hybrid piezoelectric actuator which provides high active and passive performances for smart structural systems. The actuator is composed of a pair of curved pre-stressed piezoelectric actuators, so-called commercially THUNDER actuators, installed opposite each other using two clamping mechanisms constructed of in-plane fixable hinges, grippers and solid links. A fully mathematical model is developed to describe the active and passive dynamics of the actuator and investigate the effects of its geometrical parameters on the dynamic stiffness, free displacement and blocked force properties. Among the literature that deals with piezoelectric actuators in which THUNDER elements are used as a source of electromechanical power, the proposed study is unique in that it presents a mathematical model that has the ability to predict the actuator characteristics and achieve other phenomena, such as resonances, mode shapes, phase shifts, dips, etc. For model validation, the measurements of the free dynamic response per unit voltage and passive acceleration transmissibility of a particular actuator design are used to check the accuracy of the results predicted by the model. The results reveal that there is a good agreement between the model and experiment. Another experiment is performed to teste the linearity of the actuator system by examining the variation of the output dynamic responses with varying forces and voltages at different frequencies. From the results, it can be concluded that the actuator acts approximately as a linear system at frequencies up to 1000 Hz. A parametric study is achieved here by applying the developed model to analyze the influence of the geometrical parameters of the fixable hinges on the active and passive actuator properties. The model predictions in the frequency range of 0-1000 Hz show that the hinge thickness, radius, and opening angle parameters have great effects on the frequency dynamic

  13. 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.

  14. JTIDS relative navigation with measurement sharing - Design and performance

    NASA Astrophysics Data System (ADS)

    Widnall, W. S.; Kelley, J. F.

    Alternate approaches for conducting relative navigation (relnav) using the JTIDS communication network are presented. The design and performance of the current JTIDS relnav with estimate sharing of discussed, including its shortcomings. We offer first a conceptually simpler alternate design that provides more accurate relnav between any pair of members, provided they have time to maneuver. A second alternate design includes the features of the first plus adds measurement sharing by designated primary members. It has even better performance including faster more accurate relnav fixes and relaxed maneuvering requirements. Simulation results are presented showing the superior performance of the new designs. The advantages and disadvantages of relnav with measurement sharing compared with relnav with estimate sharing are summarized.

  15. Physical performance and creative activities of centenarians.

    PubMed

    Antonini, F M; Magnolfi, S U; Petruzzi, E; Pinzani, P; Malentacchi, F; Petruzzi, I; Masotti, G

    2008-01-01

    The human functional autonomy is reduced progressively with advancing age, although a considerable proportion of the centenarians maintain a good level of autosufficiency for the basic performance of the everyday life. Even if males have a lower probability to reach the centenarian age than females do, the male centenarians display generally better functional conditions than the females. Actually, there are no systemic studies on centenarian works or activities; nevertheless, the examples of several representative persons (artists, scientists, explorers, etc.) who remained active even after this age indicate that such a possibility is realistic, and that the maintenance of vital interest and passions, thus preserving competence and professional attitudes, is not in conflict with the reaching of extreme longevity.

  16. High performances from a new design of crystal oscillator

    NASA Astrophysics Data System (ADS)

    Beuvy, G.; Marotel, G.; Renoult, P.

    1985-04-01

    This paper describes new designs developed and applied in order to increase the performance of crystal oscillators for military and space applications, requiring high performance. Results have been obtained from: (1) the developments of a new technology applied to crystal resonators; (2) the use of a low noise design of the electronics associated with the resonator; (3) highly miniaturized oven with PID control; and (4) assembly of these elements have met these specifications during mechanical environment tests.

  17. 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

  18. 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…

  19. 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.

  20. 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.

  1. 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.

  2. Manifold Regularized Experimental Design for Active Learning.

    PubMed

    Zhang, Lining; Shum, Hubert P H; Shao, Ling

    2016-12-02

    Various machine learning and data mining tasks in classification require abundant data samples to be labeled for training. Conventional active learning methods aim at labeling the most informative samples for alleviating the labor of the user. Many previous studies in active learning select one sample after another in a greedy manner. However, this is not very effective because the classification models has to be retrained for each newly labeled sample. Moreover, many popular active learning approaches utilize the most uncertain samples by leveraging the classification hyperplane of the classifier, which is not appropriate since the classification hyperplane is inaccurate when the training data are small-sized. The problem of insufficient training data in real-world systems limits the potential applications of these approaches. This paper presents a novel method of active learning called manifold regularized experimental design (MRED), which can label multiple informative samples at one time for training. In addition, MRED gives an explicit geometric explanation for the selected samples to be labeled by the user. Different from existing active learning methods, our method avoids the intrinsic problems caused by insufficiently labeled samples in real-world applications. Various experiments on synthetic datasets, the Yale face database and the Corel image database have been carried out to show how MRED outperforms existing methods.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Design and off-design performance analysis of a maximum compression/minimum drag hypersonic forebody

    NASA Technical Reports Server (NTRS)

    Hawkins, Richard W.; Richardson, Pamela F.

    1991-01-01

    The performance of a funnel-shaped hypersonic vehicle forebody is shown at its design Mach number of 15 and at two lower off-design Mach numbers. Inlet flow quality is presented by contour plots of flow angularity and pressure. Performance is indicated by mass capture ratio, total pressure recovery, kinetic energy efficiency and drag.

  10. 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.

  11. 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.

  12. Performance and design considerations in metal fueled cores. [LMFBR

    SciTech Connect

    Orechwa, Y.; Khalil, H.; Turski, R.B.

    1984-01-01

    To focus future metal fuel development requirements a study was performed to quantify the relationship between some critical core design parameters. The fuel studied was U-Pu-Zr alloy. Of interest are performance parameters, such as peak Pu enrichment, burnup swing, fast fluence, breeding ratio, and their relation to core parameters such as reactor size, degree of core heterogeneity, pin diameter, and linear heat rating. These performance parameters, while numericaly different from those of ceramic fuels, were found to exhibit the same qualitative dependence on the key design variables.

  13. 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.

  14. 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.

  15. Preliminary Tritium Management Design Activities at ORNL

    SciTech Connect

    Harrison, Thomas J.; Felde, David K.; Logsdon, Randall J.; McFarlane, Joanna; Qualls, A. L.

    2016-09-01

    Interest in salt-cooled and salt-fueled reactors has increased over the last decade (Forsberg et al. 2016). Several private companies and universities in the United States, as well as governments in other countries, are developing salt reactor designs and/or technology. Two primary issues for the development and deployment of many salt reactor concepts are (1) the prevention of tritium generation and (2) the management of tritium to prevent release to the environment (Holcomb 2013). In 2016, the US Department of Energy (DOE) initiated a research project under the Advanced Reactor Technology Program to (1) experimentally assess the feasibility of proposed methods for tritium mitigation and (2) to perform an engineering demonstration of the most promising methods. This document describes results from the first year’s efforts to define, design, and build an experimental apparatus to test potential methods for tritium management. These efforts are focused on producing a final design document as the basis for the apparatus and its scheduled completion consistent with available budget and approvals for facility use.

  16. Development of an improved active gas target design for ANASEN

    NASA Astrophysics Data System (ADS)

    Schill, Sabina; Blackmon, J. C.; Deibel, C. M.; Macon, K. T.; Rasco, B. C.; Wiedenhoever, I.

    2014-09-01

    The Array for Nuclear Astrophysics and Structure with Exotic Nuclei (ANASEN) is a charged particle detector array with an active gas target-detector capability for sensitive measurements using radioactive ion beams. One of the main goals is to improve our understanding of nuclear reactions important in stellar explosions. Following initial experimental campaigns with ANASEN, we have been developing an improved active gas target design for ANASEN that incorporates an innovative cylindrical gas ionization detector for heavy ions surrounding the beam axis inside of the other ANASEN charged particle detectors. The detection of heavy ions in coincidence with lighter ions in a redesigned proportional counter will provide greater discriminating power. The new active gas target design will be presented, and its simulated performance will be compared with test data. The Array for Nuclear Astrophysics and Structure with Exotic Nuclei (ANASEN) is a charged particle detector array with an active gas target-detector capability for sensitive measurements using radioactive ion beams. One of the main goals is to improve our understanding of nuclear reactions important in stellar explosions. Following initial experimental campaigns with ANASEN, we have been developing an improved active gas target design for ANASEN that incorporates an innovative cylindrical gas ionization detector for heavy ions surrounding the beam axis inside of the other ANASEN charged particle detectors. The detection of heavy ions in coincidence with lighter ions in a redesigned proportional counter will provide greater discriminating power. The new active gas target design will be presented, and its simulated performance will be compared with test data. This work was supported by the U.S. National Science Foundation and the Dept of Energy's Office of Science.

  17. 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

  18. 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.

  19. Design and performance of space station photovoltaic radiators

    SciTech Connect

    White, K.A.; Fleming, M.L.; Lee, A.Y.

    1993-12-31

    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.

  20. 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.

  1. 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.

  2. 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.

  3. Advances in design and performance of SHE system components

    NASA Astrophysics Data System (ADS)

    McBride, J. R.; Novak, R. F.; Schmatz, D. J.; Copple, W. B.; Brockway, J. T.

    The sodium heat engine (SHE), a thermoelectric energy conversion device that operates with no moving parts at conversion efficiencies projected to reach 25-30 percent, is discussed. Recent progress in the design and performance of components used in the development of a 1000-W SHE is reported. Advances in long-life electrodes, high-temperature ceramic-to-metal seals, electromagnetic pumps, radiation shields, and current-gathering systems are discussed. Parasitic losses and modular designs are considered.

  4. Performance Management and Optimization of Semiconductor Design Projects

    NASA Astrophysics Data System (ADS)

    Hinrichs, Neele; Olbrich, Markus; Barke, Erich

    2010-06-01

    The semiconductor industry is characterized by fast technological changes and small time-to-market windows. Improving productivity is the key factor to stand up to the competitors and thus successfully persist in the market. In this paper a Performance Management System for analyzing, optimizing and evaluating chip design projects is presented. A task graph representation is used to optimize the design process regarding time, cost and workload of resources. Key Performance Indicators are defined in the main areas cost, profit, resources, process and technical output to appraise the project.

  5. 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.

  6. Geometric design of the best performing auto-rotating wing

    NASA Astrophysics Data System (ADS)

    Liu, Yucen; Vincent, Lionel; Kanso, Eva

    2016-11-01

    Many plants use gravity and aerodynamics to disperse their seeds away from the parent plant. Various seed designs result in different dispersal modes from gliding to auto-rotating. Here, we are interested in understanding the effect of geometric design of auto-rotating seedpods on their aerodynamic performance. As an experimentally tractable surrogate to real seedpods, we investigate auto-rotating paper wings of various shape designs. We compare these designs to a control case consisting of the canonical rectangular wing. Inspired by aerodynamics, we begin by considering the benefit of an elliptical planform, and test the effect of aspect ratio on flight range and descent angle. We find the elliptical planform improves the tumbling rate and the aspect ratio has a positive effect on the flight performance of the wings. We then test two families of more complex shapes: one of tapered planform and one of a planform with sharp tips. We look for an optimal flight performance while constraining either the mass or the maximum length and width of the wing. We find that wings with sharper tips and larger length have higher auto-rotation rates and improved performance. The results imply that both the planform and length of the wing contribute to the wing's flight performance.

  7. 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.

  8. Breeder design for enhanced performance and safety characteristics

    SciTech Connect

    Fischer, G J; Atefi, B; Yang, J W; Galperin, A; Segev, M

    1980-01-01

    A fast breeder reactor design has been created which offers a considerably extended fuel cycle and excellent performance characteristics. An example of a core designed to operate on a ten-year fuel cycle is described in some detail. Use of metal fuel along with a moderator such as beryllium oxide dispersed throughout the core provides both design flexibility and safety advantages such as a strong Doppler feedback and limited sodium void reactivity gain. Local power variations are small for the entire cycle; control requirements are also modest, and fuel cycle costs are low.

  9. 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

  10. 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.

  11. Topology design and performance analysis of an integrated communication network

    NASA Technical Reports Server (NTRS)

    Li, V. O. K.; Lam, Y. F.; Hou, T. C.; Yuen, J. H.

    1985-01-01

    A research study on the topology design and performance analysis for the Space Station Information System (SSIS) network is conducted. It is begun with a survey of existing research efforts in network topology design. Then a new approach for topology design is presented. It uses an efficient algorithm to generate candidate network designs (consisting of subsets of the set of all network components) in increasing order of their total costs, and checks each design to see if it forms an acceptable network. This technique gives the true cost-optimal network, and is particularly useful when the network has many constraints and not too many components. The algorithm for generating subsets is described in detail, and various aspects of the overall design procedure are discussed. Two more efficient versions of this algorithm (applicable in specific situations) are also given. Next, two important aspects of network performance analysis: network reliability and message delays are discussed. A new model is introduced to study the reliability of a network with dependent failures. For message delays, a collection of formulas from existing research results is given to compute or estimate the delays of messages in a communication network without making the independence assumption. The design algorithm coded in PASCAL is included as an appendix.

  12. Design, Synthesis, and Monitoring of Light-Activated Motorized Nanomachines

    NASA Astrophysics Data System (ADS)

    Chiang, Pinn-Tsong

    Our group has developed a family of single molecules termed nanocars, which are aimed at performing controllable motion on surfaces. In this work, a series of light-activated motorized nanomachines incorporated with a MHz frequency light-activated unidirectional rotary motor were designed and synthesized. We hope the light-activated motor can serve as the powering unit for the nanomachines, and perform controllable translational motion on surfaces or in solution. A series of motorized nanovehicles intended for scanning tunneling microscopy (STM) imaging were designed and synthesized. A p-carborane-wheeled motorized nanocar was synthesized and monitored by STM. Single-molecule imaging was accomplished on a Cu(111) surface. However, further manipulations did lead to motor induced lateral motion. We attributed this result to the strong molecule-surface interactions between the p-carborane-wheeled nanocar and the Cu(111) surface and possible energy transfer between the rotary motor and the Cu(111) surface. To fine-tune the molecule-surface interactions, an adamantane-wheeled motorized nanocar and a three-wheel nanoroadster were designed and synthesized. In addition, the STM substrates will be varied and different combinations of molecule-surface interactions will be studied. As a complimentary imaging method to STM, single-molecule fluorescence microscopy (SMFM) also provides single-molecule level resolution. Unlike STM experiment requires ultra-high vacuum and conductive substrate, SMFM experiment is conducted at ambient conditions and uses non-conductive substrate. This imaging method allows us to study another category of molecule-surface interactions. We plan to design a fluorescent motorized nanocar that is suitable for SMFM studies. However, both the motor and fluorophore are photochemically active molecules. In proximity, some undesired energy transfer or interference could occur. A cyanine 5- (cy5-) tagged motorized nanocar incorporated with the MHz motor was

  13. 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

  14. Enhanced-performance active fiber composites

    NASA Astrophysics Data System (ADS)

    Gentilman, Richard L.; McNeal, Kelley; Schmidt, Gerald E.; Pizzochero, Alessandro E.; Rossetti, George A., Jr.

    2003-08-01

    Active fiber composites (AFCs) find applications in a variety of industrial, commercial, and aerospace markets as both actuators and sensors. Among the key attributes of AFCs relative to conventional monolithic piezoceramic actuators are high strain energy density, unidirectional response, conformability, and robustness. Recently, performance enhancements in AFCs have been demonstrated through the use of a modified injection molding process to produce piezoceramic modules with multiple identical fibers of a uniform rectangular cross section. AFC actuators made from Type II PZT fiber modules exhibit free micro-strains of 1830 +/- 30 ppm at a peak-peak E-field drive of 26.1 kV/cm, and show exceptional part-to-part uniformity. In addition, AFCs made from injection molded PMN-PT fiber modules show a low-field d33 of 650 pm/V. The successful incorporation of PMN-PT materials into AFCs also demonstrates the viability of using highly textured ceramic PMN-PT piezofibers, for which even larger increases in strain response are expected.

  15. Implications of tiling for performance and design flow

    NASA Astrophysics Data System (ADS)

    Demircan, Ertugrul; Tian, Ruiqi; Grobman, Warren D.

    2002-07-01

    In this paper, we discuss rule-based and model-based tiling methodologies for interconnect layers and their implications for design flows and performance. The addition of these 'dummy' tiling metal features modifies the final physical design and reduces the variation of back-end process parameters. This is a newly developing area of design flow and its importance is increasing with each succeeding semiconductor generation. Along with this development new methodologies and tools need to be introduced to handle time placement post-physical design, as well as efficient methods for representing the resulting large amount of dat. Additionally, the inclusion of tiles may introduce performance-degrading parasitic effects. The situation is complicated by the order of the elements of the design flow: parasitics characterization requires knowledge about the placement of dummy metal times, which takes place after physical design. In this study, we co pare the advantages of having uniform interconnect characteristics to the performance degradation caused by the additional layout parasitics. We also discuss several possible scenarios for the modification of design flows to account for these effects the thereby recover timing and power targets closure. These scenarios depend for their success on the very different length scales of polish and electromagnetic effects. Finally, an analysis of correlations in the parameters that define design corners leads to the new conclusion that the negative effect of increased parasitic loading due to tiling is not as sever as a simple analysis would suggest. This result is due to the fact that the tiling parasitic loading is somewhat compensated for by the improved planarity resulting from tiling, which tightens the process variation-induced spread of metal electrical parameters.

  16. Webpage aesthetics, performance and usability: design variables and their effects.

    PubMed

    Schmidt, Kristi E; Liu, Yili; Sridharan, Srivatsan

    2009-06-01

    The primary objectives of this research are to identify the underlying clusters of design variables affecting the perceived usability of a webpage and to examine the effects of webpage design variables on webpage performance. Fifty-seven design variables and 10 underlying clusters that conceptualise the structure of user webpage judgement are identified through content analysis on literature and structured interviews, balanced incomplete block user survey administration and cluster analysis. Five clusters are selected to conduct three experiments that quantify the change in user aesthetic preference, perceived ease of interaction and interaction speed as a function of loading speed, image colour, image size, font size, link style, and column width. Results show that user performance alone is not a good indicator of aesthetic judgement and overall effectiveness of a webpage. The value of integrating global construct analysis processes and local controlled experimentation processes in ergonomic interface research is illustrated. Fifty-seven webpage design variables are defined, ranked and clustered according to perceived importance and overall preference. Experimental results illustrate that both technical performance and aesthetic factors are important webpage design considerations.

  17. Key issues in the design of pay for performance programs.

    PubMed

    Eijkenaar, Frank

    2013-02-01

    Pay for performance (P4P) is increasingly being used to stimulate healthcare providers to improve their performance. However, evidence on P4P effectiveness remains inconclusive. Flaws in program design may have contributed to this limited success. Based on a synthesis of relevant theoretical and empirical literature, this paper discusses key issues in P4P-program design. The analysis reveals that designing a fair and effective program is a complex undertaking. The following tentative conclusions are made: (1) performance is ideally defined broadly, provided that the set of measures remains comprehensible, (2) concerns that P4P encourages "selection" and "teaching to the test" should not be dismissed, (3) sophisticated risk adjustment is important, especially in outcome and resource use measures, (4) involving providers in program design is vital, (5) on balance, group incentives are preferred over individual incentives, (6) whether to use rewards or penalties is context-dependent, (7) payouts should be frequent and low-powered, (8) absolute targets are generally preferred over relative targets, (9) multiple targets are preferred over single targets, and (10) P4P should be a permanent component of provider compensation and is ideally "decoupled" form base payments. However, the design of P4P programs should be tailored to the specific setting of implementation, and empirical research is needed to confirm the conclusions.

  18. 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.

  19. 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.

  20. Research on performance-based seismic design criteria

    NASA Astrophysics Data System (ADS)

    Xie, Li-Li; Ma, Yu-Hong

    2002-03-01

    The seismic design criterion adopted in the existing seismic design codes is reviewed. It is pointed out that the presently used seismic design criterion is not satisfied with the requirements of nowadays social and economic development. A new performance-based seismic design criterion that is composed of three components is presented in this paper. It can not only effectively control the economic losses and casualty, but also ensure the building’s function in proper operation during earthquakes. The three components are: classification of seismic design for buildings, determination of seismic design intensity and/or seismic design ground motion for controlling seismic economic losses and casualties, and determination of the importance factors in terms of service periods of buildings. For controlling the seismic human losses, the idea of socially acceptable casualty level is presented and the ‘Optimal Economic Decision Model’ and ‘Optimal Safe Decision Model’ are established. Finally, a new method is recommended for calculating the importance factors of structures by adjusting structures service period on the base of more important structure with longer service period than the conventional ones. Therefore, the more important structure with longer service periods will be designed for higher seismic loads, in case the exceedance probability of seismic hazard in different service period is same.

  1. 24 CFR 902.11 - PHAS performance designation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 4 2013-04-01 2013-04-01 false PHAS performance designation. 902.11 Section 902.11 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND INDIAN HOUSING, DEPARTMENT OF HOUSING AND...

  2. Design and performance verification of advanced multistage depressed collectors

    NASA Technical Reports Server (NTRS)

    Kosmahl, H. G.; Ramins, P.

    1975-01-01

    Design and performance of a small size, 4 stage depressed collector are discussed. The collector and a spent beam refocusing section preceding it are intended for efficiency enhancement of octave bandwidth, high CW power traveling wave tubes for use in ECM.

  3. 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.

  4. 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…

  5. 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…

  6. Wireless imaging sensor network design and performance analysis

    NASA Astrophysics Data System (ADS)

    Sundaram, Ramakrishnan

    2016-05-01

    This paper discusses (a) the design and implementation of the integrated radio tomographic imaging (RTI) interface for radio signal strength (RSS) data obtained from a wireless imaging sensor network (WISN) (b) the use of model-driven methods to determine the extent of regularization to be applied to reconstruct images from the RSS data, and (c) preliminary study of the performance of the network.

  7. Design and performance analysis of digital acoustic underwater telemetry system

    NASA Astrophysics Data System (ADS)

    Catipovic, J. A.; Baggeroer, A. B.; Vonderheydt, K.; Koelsch, D. E.

    1985-11-01

    The work discusses the design and performance characteristics of a Digital Acoustic Telemetry System (DATS) which incorporates the current state-of-the-art technology and is capable of reliable data transmission at rates useful to a wide range of ocean exploration and development gear.

  8. 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.

  9. Design and Ballistic Performance of Hybrid Composite Laminates

    NASA Astrophysics Data System (ADS)

    Ćwik, Tomasz K.; Iannucci, Lorenzo; Curtis, Paul; Pope, Dan

    2016-10-01

    This paper presents an initial design assessment of a series of novel, cost-effective, and hybrid composite materials for applications involving high velocity impacts. The proposed hybrid panels were designed in order to investigate various physical phenomenon occurring during high velocity impact on compliant laminates from a previous study on Dyneema® and Spectra®. In the first, screening phase of the study twenty different hybrid composite laminates were impacted with 20 mm Fragment Simulating Projectiles at 1 km/s striking velocity. The best performing concepts were put forward to phase II with other hybrid concepts involving shear thickening fluids, commonly used in low velocity impacts. The results indicated that it is possible to design hybrid laminates of similar ballistic performance as the reference Dyneema® laminate, but with lower material costs. The optimal hybrid concept involves a fibre reinforced Polypropylene front and a Dyneema® backing.

  10. Design, fabrication and performance of high efficiency photovoltaic modules

    NASA Technical Reports Server (NTRS)

    Nowlan, M. J.; Kreisman, W. S.; Younger, P. R.

    1981-01-01

    Design details and performance and environmental test results of newly developed high performance and reliability photovoltaic modules are presented. Efficiencies averaging 14.3% for 3040 cells were obtained by using ion implantation for cell junction and back surface field formation. 152 rectangular (6.0 cm x 4.6 cm) cells arranged with a 97% local packing density comprise the circuit assembly, and cells are wired 4 in parallel by 38 in series. The top cover of the superstrate design module is composed of tempered low-iron glass to provide transparent protection for the optical surface. Results show that this design has an encapsulation system which does not fail in the event of reverse-bias operation, and an average module efficiency of 12.2% was achieved at a 58.6W power which varied only 2% among all 20 modules.

  11. Design of a Pushbroom Imaging Spectrometer that Exceeds AVIRIS Performance

    NASA Technical Reports Server (NTRS)

    Green, Robert O.

    2004-01-01

    This slide presentation reviews the design of a Pushbroom Imaging Spectrometer, that will exceed the performance of Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). The approach for the AVIRIS-II instrument is reviewed as are the specifications for the new spectrometer. Even though the pushbroom spectrometer is inherently non-uniform, the design of the AVIRIS-II provides for uniformity. Spot diagrams at the slit and at the detector inside the 27micron box are presented. A few of the challenges in the mechanical design and the making of the slit are discussed. The specifications of the 6604A detector array are reviewed. Slides showing the expected Signal to Noise Ratio performance are presented.

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. Improved Hypersonic Inlet Performance Using Validated Strut Compression Designs

    NASA Technical Reports Server (NTRS)

    Bulman, M. J.; Stout, P. W.; Fernandez, R.

    1997-01-01

    Aerojet is currently executing two Strutjet propulsion contracts: one a Rocket Based Combined Cycle (RBCC) engine for a NASA-Marshall Space Flight Center (MSFC) Advanced Reusable Transportation Technology (ARTT) program, the second a Dual Mode Ram/Scramjet engine for a USAF Wright Laboratories Storable Fuel Scramjet Flow Path Concepts program. The engines employed in both programs operate at supersonic and low hypersonic speeds and use inlets employing forebody external and sidewall compression. Aerojet has developed and validated a successful design methodology applicable to these inlet types. Design features include an integrated vehicle forebody, external side compression struts, strut sidewall and throat bleed, a throat shock trap, and variable geometry internal contraction. Computation Fluid Dynamic (CFD) predictions and test data show these inlets allow substantially increased flow turning angles over other designs. These increased flow turning angles allow shorter and lighter engines than current designs, which in turn enables higher performing vehicles with broad operating characteristics. This paper describes the designs of two different inlets evaluated by the NASA-MSFC and USAF programs, discusses the results of wind tunnel tests performed by NASA-Lewis Research Center, and provides correlations of test data with CFD predictions. Parameters of interest include low Mach number starting capability, start sensitivity as a function of back pressure at various contraction ratios, flow turning angles, strut and throat bleed effects, and pressure recovery at various Mach numbers.

  17. Performance enhancement of a pump impeller using optimal design method

    NASA Astrophysics Data System (ADS)

    Jeon, Seok-Yun; Kim, Chul-Kyu; Lee, Sang-Moon; Yoon, Joon-Yong; Jang, Choon-Man

    2017-04-01

    This paper presents the performance evaluation of a regenerative pump to increase its efficiency using optimal design method. Two design parameters which define the shape of the pump impeller, are introduced and analyzed. Pump performance is evaluated by numerical simulation and design of experiments(DOE). To analyze three-dimensional flow field in the pump, general analysis code, CFX, is used in the present work. Shear stress turbulence model is employed to estimate the eddy viscosity. Experimental apparatus with an open-loop facility is set up for measuring the pump performance. Pump performance, efficiency and pressure, obtained from numerical simulation are validated by comparison with the results of experiments. Throughout the shape optimization of the pump impeller at the operating flow condition, the pump efficiency is successfully increased by 3 percent compared to the reference pump. It is noted that the pressure increase of the optimum pump is mainly caused by higher momentum force generated inside blade passage due to the optimal blade shape. Comparisons of pump internal flow on the reference and optimum pump are also investigated and discussed in detail.

  18. 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.

  19. 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.

  20. The SKA1 LOW telescope: system architecture and design performance

    NASA Astrophysics Data System (ADS)

    Waterson, Mark F.; Labate, Maria Grazia; Schnetler, Hermine; Wagg, Jeff; Turner, Wallace; Dewdney, Peter

    2016-07-01

    The SKA1-LOW radio telescope will be a low-frequency (50-350 MHz) aperture array located in Western Australia. Its scientific objectives will prioritize studies of the Epoch of Reionization and pulsar physics. Development of the telescope has been allocated to consortia responsible for the aperture array front end, timing distribution, signal and data transport, correlation and beamforming signal processors, infrastructure, monitor and control systems, and science data processing. This paper will describe the system architectural design and key performance parameters of the telescope and summarize the high-level sub-system designs of the consortia.

  1. DESIGN POINT PERFORMANCE OF TURBOJET AND TURBOFAN ENGINE CYCLES

    NASA Technical Reports Server (NTRS)

    Vanco, M. R.

    1994-01-01

    This program is one designed for the calculation of design-point performance of turbojet and turbofan engine cycles. This program requires as input the airplane Mach number, the altitude-state equations, turbine-inlet temperature, afterburner temperature, duct burner temperature, bypass ratio, coolant flow, component efficiences, and component pressure ratios. The output yields specific thrust, specific fuel consumption, engine efficiency, and several component temperatures and pressures. The thermodynamic properties of the gas are expressed as functions of temperature and fuel-to-air ratio. The program is provided with an example case. The program has been implemented on the IBM 7094.

  2. 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.

  3. Design and performance analysis of gas and liquid radial turbines

    NASA Astrophysics Data System (ADS)

    Tan, Xu

    In the first part of the research, pumps running in reverse as turbines are studied. This work uses experimental data of wide range of pumps representing the centrifugal pumps' configurations in terms of specific speed. Based on specific speed and specific diameter an accurate correlation is developed to predict the performances at best efficiency point of the centrifugal pump in its turbine mode operation. The proposed prediction method yields very good results to date compared to previous such attempts. The present method is compared to nine previous methods found in the literature. The comparison results show that the method proposed in this paper is the most accurate. The proposed method can be further complemented and supplemented by more future tests to increase its accuracy. The proposed method is meaningful because it is based both specific speed and specific diameter. The second part of the research is focused on the design and analysis of the radial gas turbine. The specification of the turbine is obtained from the solar biogas hybrid system. The system is theoretically analyzed and constructed based on the purchased compressor. Theoretical analysis results in a specification of 100lb/min, 900ºC inlet total temperature and 1.575atm inlet total pressure. 1-D and 3-D geometry of the rotor is generated based on Aungier's method. 1-D loss model analysis and 3-D CFD simulations are performed to examine the performances of the rotor. The total-to-total efficiency of the rotor is more than 90%. With the help of CFD analysis, modifications on the preliminary design obtained optimized aerodynamic performances. At last, the theoretical performance analysis on the hybrid system is performed with the designed turbine.

  4. 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.

  5. 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.

  6. Learning Design--Creative Design to Visualise Learning Activities

    ERIC Educational Resources Information Center

    Toetenel, Lisette; Rienties, Bart

    2016-01-01

    The focus on quality improvements by institutions for better online and blended teaching can be delivered in different ways. This article reports on the implementation of this process and the approaches taken first, in terms of the design of new learning materials, and second, when reviewing the existing curriculum. The study aims to ascertain…

  7. Photovoltaic concentrators: performance and reliability data and future design directions

    SciTech Connect

    Edenburn, M.W.; Boes, E.C.

    1984-05-01

    This paper will summarize the status and discuss likely future directions of photovoltaic concentrator technology. A current commercial Si cell module has a peak efficiency of 15.5%, and 17% has been reached for an experimental module. Advanced cells and module design improvements offer still higher efficiencies. Concentrator Fresnel lens array fields installed several years ago have all demonstrated very good electrical performance with little performance degradation. Fresnel lens arrays are commercially available and prices of $7/watt for installed one megawatt systems have been quoted. Cost projections predict that current technology concentrating PV arrays can be installed for less than $2/watt if they are manufactured in large, steady quantities. More advanced designs may cost even less.

  8. Photovoltaic concentrators: Performance and reliability data and future design directions

    SciTech Connect

    Edenbrum, M.

    1984-05-01

    This paper will summarize the status and discuss likely future directions of photovoltaic concentrator technology. A current commercial Si cell module has a peak efficiency of 15.5%, and 17% has been reached for an experimental module. Advanced cells and module design improvements offer still higher efficiencies. Concentrator Fresnel lens array fields installed several years ago have all demonstrated very good electrical performance with little performance degradation. Fresnel lens arrays are commercially available and prices of $7/watt for installed one megawatt systems have been quoted. Cost projections predict that current technology concentrating PV arrays can be installed for less than $2/watt if they are manufactured in large, steady quantities. More advanced designs may cost even less.

  9. 4MOST fiber feed preliminary design: prototype testing and performance

    NASA Astrophysics Data System (ADS)

    Haynes, Dionne M.; Kelz, Andreas; Barden, Samuel C.; Bauer, Svend-Marian; Ehrlich, Katjana; Haynes, Roger; Jahn, Thomas; Saviauk, Allar; de Jong, Roelof S.

    2016-08-01

    The 4MOST instrument is a multi-object-spectrograph for the ESO-VISTA telescope. The 4MOST fiber feed subsystem is composed of a fiber positioner (AESOP) holding 2436 science fibers based on the Echidna tilting spine concept, and the fiber cable, which feeds two low-resolution spectrographs (1624 fibers) and one high-resolution spectrograph (812 fibers). In order to optimize the fiber feed subsystem design and provide essential information required for the spectrograph design, prototyping and testing has been undertaken. In this paper we give an overview of the current fiber feed subsystem design and present the preliminary FRD, scrambling, throughput and system performance impact results for: maximum and minimum spine tilt, fiber connectors, cable de-rotator simulator for fiber cable lifetime tests.

  10. 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.

  11. 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.

  12. 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.

  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. 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.

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

    PubMed

    Zhang, Yutao; Xuan, Yimin

    2016-07-13

    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.

  16. 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)

  17. 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.

  18. 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.

  19. 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.

  20. Challenges and solutions for high performance SWIR lens design

    NASA Astrophysics Data System (ADS)

    Gardner, M. C.; Rogers, P. J.; Wilde, M. F.; Cook, T.; Shipton, A.

    2016-10-01

    Shortwave infrared (SWIR) cameras are becoming increasingly attractive due to the improving size, resolution and decreasing prices of InGaAs focal plane arrays (FPAs). The rapid development of competitively priced HD performance SWIR cameras has not been matched in SWIR imaging lenses with the result that the lens is now more likely to be the limiting factor in imaging quality than the FPA. Adapting existing lens designs from the visible region by re-coating for SWIR will improve total transmission but diminished image quality metrics such as MTF, and in particular large field angle performance such as vignetting, field curvature and distortion are serious consequences. To meet this challenge original SWIR solutions are presented including a wide field of view fixed focal length lens for commercial machine vision (CMV) and a wide angle, small, lightweight defence lens and their relevant design considerations discussed. Issues restricting suitable glass types will be examined. The index and dispersion properties at SWIR wavelengths can differ significantly from their visible values resulting in unusual glass combinations when matching doublet elements. Materials chosen simultaneously allow athermalization of the design as well as containing matched CTEs in the elements of doublets. Recently, thinned backside-illuminated InGaAs devices have made Vis.SWIR cameras viable. The SWIR band is sufficiently close to the visible that the same constituent materials can be used for AR coatings covering both bands. Keeping the lens short and mass low can easily result in high incidence angles which in turn complicates coating design, especially when extended beyond SWIR into the visible band. This paper also explores the potential performance of wideband Vis.SWIR AR coatings.

  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.

  2. Extravehicular Activity training and hardware design considerations

    NASA Technical Reports Server (NTRS)

    Thuot, Pierre J.; Harbaugh, Gregory J.

    1993-01-01

    Designing hardware that can be successfully operated by EVA astronauts for EVA tasks required to assemble and maintain Space Station Freedom requires a thorough understanding of human factors and of the capabilities and limitations of the space-suited astronaut, as well as of the effect of microgravity environment on the crew member's capabilities and on the overhead associated with EVA. This paper describes various training methods and facilities that are being designed for training EVA astronauts for Space Station assembly and maintenance, taking into account the above discussed factors. Particular attention is given to the user-friendly hardware design for EVA and to recent EVA flight experience.

  3. 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

  4. 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.

  5. Design and Performance of a 560-Microsecond Ku-Band Binary Fiber-Optic Delay Line

    DTIC Science & Technology

    2015-05-14

    photodiode. 5. Press the laser power button on the front panel. The ring illuminator on the button will light. This button activates the current drivers for...Naval Research Laboratory Washington, DC 20375-5320 NRL/MR/5650--15-9545 Design and Performance of a 560-Microsecond Ku-Band Binary Fiber -Optic Delay...THIS PAGE 18. NUMBER OF PAGES 17. LIMITATION OF ABSTRACT Design and Performance of a 560-Microsecond Ku-Band Binary Fiber -Optic Delay Line Joseph M

  6. Optimization of oar blade design for improved performance in rowing.

    PubMed

    Caplan, Nicholas; Gardner, Trevor N

    2007-11-01

    The aim of the present study was to find a more optimal blade design for rowing performance than the Big Blade, which has been shown to be less than optimal for propulsion. As well as the Big Blade, a flat Big Blade, a flat rectangular blade, and a rectangular blade with the same curvature and projected area as the Big Blade were tested in a water flume to determine their fluid dynamic characteristics at the full range of angles at which the oar blade might present itself to the water. Similarities were observed between the flat Big Blade and rectangular blades. However, the curved rectangular blade generated significantly more lift in the angle range 0-90 degrees than the curved Big Blade, although it was similar between 90 and 180 degrees. This difference was attributed to the shape of the upper and lower edges of the blade and their influence on the fluid flow around the blade. Although the influence of oar blade design on boat speed was not investigated here, the significant increases in fluid force coefficients for the curved rectangular blade suggest that this new oar blade design could elicit a practically significant improvement in rowing performance.

  7. High performance cluster system design for remote sensing data processing

    NASA Astrophysics Data System (ADS)

    Shi, Yuanli; Shen, Wenming; Xiong, Wencheng; Fu, Zhuo; Xiao, Rulin

    2012-10-01

    During recent years, cluster systems have played a more important role in the architecture design of high-performance computing area which is cost-effective and efficient parallel computing system able to satisfy specific computational requirements in the earth and space sciences communities. This paper presents a powerful cluster system built by Satellite Environment Center, Ministry of Environment Protection of China that is designed to process massive remote sensing data of HJ-1 satellites automatically everyday. The architecture of this cluster system including hardware device layer, network layer, OS/FS layer, middleware layer and application layer have been given. To verify the performance of our cluster system, image registration has been chose to experiment with one scene of HJ-1 CCD sensor. The experiments of imagery registration shows that it is an effective system to improve the efficiency of data processing, which could provide a response rapidly in applications that certainly demand, such as wild land fire monitoring and tracking, oil spill monitoring, military target detection, etc. Further work would focus on the comprehensive parallel design and implementations of remote sensing data processing.

  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. Nicotinamide phosphoribosyltransferase inhibitors, design, preparation, and structure-activity relationship.

    PubMed

    Christensen, Mette K; Erichsen, Kamille D; Olesen, Uffe H; Tjørnelund, Jette; Fristrup, Peter; Thougaard, Annemette; Nielsen, Søren Jensby; Sehested, Maxwell; Jensen, Peter B; Loza, Einars; Kalvinsh, Ivars; Garten, Antje; Kiess, Wieland; Björkling, Fredrik

    2013-11-27

    Existing pharmacological inhibitors for nicotinamide phosphoribosyltransferase (NAMPT) are promising therapeutics for treating cancer. By using medicinal and computational chemistry methods, the structure-activity relationship for novel classes of NAMPT inhibitors is described, and the compounds are optimized. Compounds are designed inspired by the NAMPT inhibitor APO866 and cyanoguanidine inhibitor scaffolds. In comparison with recently published derivatives, the new analogues exhibit an equally potent antiproliferative activity in vitro and comparable activity in vivo. The best performing compounds from these series showed subnanomolar antiproliferative activity toward a series of cancer cell lines (compound 15: IC50 0.025 and 0.33 nM, in A2780 (ovarian carcinoma) and MCF-7 (breast), respectively) and potent antitumor in vivo activity in well-tolerated doses in a xenograft model. In an A2780 xenograft mouse model with large tumors (500 mm(3)), compound 15 reduced the tumor volume to one-fifth of the starting volume at a dose of 3 mg/kg administered ip, bid, days 1-9. Thus, compounds found in this study compared favorably with compounds already in the clinic and warrant further investigation as promising lead molecules for the inhibition of NAMPT.

  10. Design of phosphorylated dendritic architectures to promote human monocyte activation.

    PubMed

    Poupot, Mary; Griffe, Laurent; Marchand, Patrice; Maraval, Alexandrine; Rolland, Olivier; Martinet, Ludovic; L'Faqihi-Olive, Fatima-Ezzahra; Turrin, Cédric-Olivier; Caminade, Anne-Marie; Fournié, Jean-Jacques; Majoral, Jean-Pierre; Poupot, Rémy

    2006-11-01

    As first defensive line, monocytes are a pivotal cell population of innate immunity. Monocyte activation can be relevant to a range of immune conditions and responses. Here we present new insights into the activation of monocytes by a series of phosphonic acid-terminated, phosphorus-containing dendrimers. Various dendritic or subdendritic structures were synthesized and tested, revealing the basic structural requirements for monocyte activation. We showed that multivalent character and phosphonic acid capping of dendrimers are crucial for monocyte targeting and activation. Confocal videomicroscopy showed that a fluorescein-tagged dendrimer binds to isolated monocytes and gets internalized within a few seconds. We also found that dendrimers follow the phagolysosomial route during internalization by monocytes. Finally, we performed fluorescence resonance energy transfer (FRET) experiments between a specifically designed fluorescent dendrimer and phycoerythrin-coupled antibodies. We showed that the typical innate Toll-like receptor (TLR)-2 is clearly involved, but not alone, in the sensing of dendrimers by monocytes. In conclusion, phosphorus-containing dendrimers appear as precisely tunable nanobiotools able to target and activate human innate immunity and thus prove to be good candidates to develop new drugs for immunotherapies.

  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.

  12. 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.

  13. Experimental investigation of design parameters on dry powder inhaler performance.

    PubMed

    Ngoc, Nguyen Thi Quynh; Chang, Lusi; Jia, Xinli; Lau, Raymond

    2013-11-30

    The study aims to investigate the impact of various design parameters of a dry powder inhaler on the turbulence intensities generated and the performance of the dry powder inhaler. The flow fields and turbulence intensities in the dry powder inhaler are measured using particle image velocimetry (PIV) techniques. In vitro aerosolization and deposition a blend of budesonide and lactose are measured using an Andersen Cascade Impactor. Design parameters such as inhaler grid hole diameter, grid voidage and chamber length are considered. The experimental results reveal that the hole diameter on the grid has negligible impact on the turbulence intensity generated in the chamber. On the other hand, hole diameters smaller than a critical size can lead to performance degradation due to excessive particle-grid collisions. An increase in grid voidage can improve the inhaler performance but the effect diminishes at high grid voidage. An increase in the chamber length can enhance the turbulence intensity generated but also increases the powder adhesion on the inhaler wall.

  14. 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.

  15. Design and Performance Frameworks for Constructing Problem-Solving Simulations

    PubMed Central

    Stevens, Ron; 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 ideally would be guided less by the strengths/limitations of the presentation media and more by cognitive analyses detailing the goals of the tasks, the needs and abilities of students, and the resulting decision outcomes needed by different audiences. This article describes a problem-solving environment and associated theoretical framework for investigating how students select and use strategies as they solve complex science problems. A framework is first described for designing on-line problem spaces that highlights issues of content, scale, cognitive complexity, and constraints. While this framework was originally designed for medical education, it has proven robust and has been successfully applied to learning environments from elementary school through medical school. Next, a similar framework is detailed for collecting student performance and progress data that can provide evidence of students' strategic thinking and that could potentially be used to accelerate student progress. Finally, experimental validation data are presented that link strategy selection and use with other metrics of scientific reasoning and student achievement. PMID:14506505

  16. Orion Entry, Descent, and Landing Performance and Mission Design

    NASA Technical Reports Server (NTRS)

    Broome, Joel M.; Johnson, Wyatt

    2007-01-01

    The Orion Vehicle is the next spacecraft to take humans into space and will include missions to ISS as well as missions to the Moon. As part of that challenge, the vehicle will have to accommodate multiple mission design concepts, since return from Low Earth Orbit and return from the Moon can be quite different. Commonality between the different missions as it relates to vehicle systems, guidance capability, and operations concepts is the goal. Several unique mission design concepts include the specification of multiple land-based landing sites for a vehicle with closed-loop direct and skip entry guidance, followed by a parachute descent and landing attenuation system. This includes the ability of the vehicle to accurately target and land at a designated landing site, including site location aspects, landing site size, and landing opportunities assessments. Analyses associated with these mission design and flight performance challenges and constraints will be discussed as well as potential operational concepts to provide feasibility and/or mission commonality.

  17. 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.

  18. 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.

  19. 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), 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.

  20. 4MOST low-resolution spectrograph: design and performances

    NASA Astrophysics Data System (ADS)

    Laurent, F.; Kosmalski, Johan; Boudon, Didier; Caillier, Patrick; Daguisé, Eric; Migniau, Jean-Emmanuel; Pécontal, Arlette; Richard, Johan; Barden, Samuel C.; Bellido-Tirado, Olga; Frey, Steffen; Saviauk, Allar

    2016-08-01

    4MOST, the 4m Multi Object Spectroscopic Telescope, is an upcoming optical, fibre-fed, MOS facility for the VISTA telescope at ESO's Paranal Observatory in Chile. Its main science drivers are in the fields of galactic archeology, highenergy physics, galaxy evolution and cosmology. The preliminary design of 4MOST features 2436 fibres split into lowresolution (1624 fibres, 370-950 nm, R > 4000) and high-resolution spectrographs (812 fibres, three arms, 44-69 nm coverage each, R >18000) with a fibre positioner and covering an hexagonal field of view of 4.1 deg2. The 4MOST consortium consists of several institutes in Europe and Australia under leadership of the Leibniz-Institut für Astrophysik, Potsdam (AIP). 4MOST is currently in its Preliminary Design Phase with an expected start of science operations in 2021. Two third of fibres go to two Low Resolution Spectrographs with three channels per spectrograph. Each low resolution spectrograph is composed of 812 scientific and 10 calibration fibres using 85μm core fibres at f/3, a 200mm beam for an off-axis collimator associated to its Schmidt corrector, 3 arms with f/1.73 cameras and standard 6k x 6k 15μm pixel detectors. CRAL has the responsibility of the Low Resolution Spectrographs. In this paper, the optical design and performances of 4MOST Low Resolution Spectrograph designed for 4MOST PDR in June, 2016 will be presented. Special emphasis will be put on the Low Resolution Spectrograph system budget and performance analysis.

  1. 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.

  2. 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.

  3. 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

  4. 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.

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

    NASA Technical Reports Server (NTRS)

    Condon, Gerald L.; Lee, David E.; Carson, John M., III

    2017-01-01

    On December 11, 1972, Apollo 17 marked the last controlled U.S. lunar landing and was followed by an absence of methodical in-situ investigation of the lunar surface. The Moon Age and Regolith Explorer (MARE) proposal provides scientific measurement of the age and composition of a relatively young portion of the lunar surface near Aristarchus Plateau and the first post-Apollo U.S. soft lunar landing. It includes the first demonstration of a crew survivability-enhancing autonomous hazard detection and avoidance system. This report focuses on the mission design and performance associated with the MARE robotic lunar landing subject to mission and trajectory constraints.

  6. 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.

  7. Cognitive Activity-based Design Methodology for Novice Visual Communication Designers

    ERIC Educational Resources Information Center

    Kim, Hyunjung; Lee, Hyunju

    2016-01-01

    The notion of design thinking is becoming more concrete nowadays, as design researchers and practitioners study the thinking processes involved in design and employ the concept of design thinking to foster better solutions to complex and ill-defined problems. The goal of the present research is to develop a cognitive activity-based design…

  8. 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.

  9. 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.

  10. 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.

  11. Yield-enhanced routing for high-performance VLSI designs

    NASA Astrophysics Data System (ADS)

    Venkataraman, Arunshankar; Chen, Howard H.; Koren, Israel

    1997-09-01

    It is widely recognized that interconnects will be the main bottleneck in enhancing the performance of future deep sub-micron VLSI designs. Interconnects do not "scale" well with decreasing feature sizes and therefore dominate the delays in the integrated circuit. In addition to RC delays, crosstalk noise also contributes significantly to the delays experienced by a signal. Interconnects are more susceptible to manufacturing defects and therefore affect the product yields significantly. Recently, several channel-routing based solutions have been proposed to minimize crosstalk noise and also enhance yield of the routing. While these approaches are effective, they do not provide maximum benefits as they are either constrained by a particular design methodology or are post-routing steps which have limited scope for significant improvement. Also, design for manufacturabiity objectives have not been fully exploited by VLSI CAD tools as they do not integrate seamlessly into the conventional design flow and the added overheads make it less attractive. In this paper, we propose a modified routing algorithm that maximizes yield and reduces crosstalk noise while using minimal area for the routing. The yield enhancement objective has been integrated into the routing phase as a preferred constraint (a constraint that will be satisfied only if the primary constraints of minimal area and wire length have been satisfied) and fits well into the conventional design flow. This enables the router to produce an output which provides maximum achievable critical area reduction for the given routing solution. Post-routing layout modification is also done with the objective of minimizing the interaction area between the interconnects by exploiting the gridless property of the router. The above algorithm is incorporated into GLITTER (the gridless, variable width channel router), and the results on channel-routing benchmarks are presented. These results show a significant reduction in the

  12. 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…

  13. Scientists Design Heat-Activated Penis Implant

    MedlinePlus

    ... implant, Le used a heat-activated exoskeleton of nitinol, a metal known for its elasticity. A urologist could do a simplified operation to insert the nitinol implant, which would remain flaccid at body temperature ...

  14. Advanced Performance Modeling with Combined Passive and Active Monitoring

    SciTech Connect

    Dovrolis, Constantine; Sim, Alex

    2015-04-15

    To improve the efficiency of resource utilization and scheduling of scientific data transfers on high-speed networks, the "Advanced Performance Modeling with combined passive and active monitoring" (APM) project investigates and models a general-purpose, reusable and expandable network performance estimation framework. The predictive estimation model and the framework will be helpful in optimizing the performance and utilization of networks as well as sharing resources with predictable performance for scientific collaborations, especially in data intensive applications. Our prediction model utilizes historical network performance information from various network activity logs as well as live streaming measurements from network peering devices. Historical network performance information is used without putting extra load on the resources by active measurement collection. Performance measurements collected by active probing is used judiciously for improving the accuracy of predictions.

  15. Performance analysis for second-design space Stirling engine model

    NASA Astrophysics Data System (ADS)

    Ogiwara, Sachio; Fujiwara, Tsutomu; Eguchi, Kunihisa; Nakamura, Yoshihiro

    A hybrid free-piston Stirling research engine, called NALSEM 125, has been tested since 1988 as part of a solar dynamic power technology program. It is a gamma-type Stirling driven linear-alternator machine with helium as a working fluid. The objective of the experimental program is to understand the thermodynamic and dynamic mechanisms of the free piston engine integrated with a magnet-moving alternator. After the first phase engine experiments of NALSEM 125, a second design Stirling engine of NALSEM 125 R has been tested. By using a second-order analytical tool, some design modifications were performed to provide much more stable dynamic operations over a required operating range, as well as to incorporate an electric heater head simulating a hot interface of 12 sodium heat pipes. Describes in this paper are thermodynamic performance data of NALSEM 125R operations, which are also compared with the computational analysis, considering the power losses resulting from pressure drop and gas leakage.

  16. The design and performance of high-temperature irradiation capsules

    SciTech Connect

    Greenslade, D.L.; Knight, R.C.; Ermi, A.M.

    1990-03-01

    Characterization of high-temperature materials behavior in a neutron environment will be required to develop reliable performance prediction models for high-temperature gas-cooled, space power, and fusion reactors. One vehicle by which material behavior in a fast neutron environment can be studied is the Materials Open Test Assembly (MOTA) in the Fast Flux Facility (FFTF). Until recently, irradiation temperatures in the MOTA were limited to 1075 K. A recent successful experiment, however, has extended the temperature capability in the MOTA to 1500 K. This report describes the design and performance of high-temperature capsules that were used in that experiment. Each of eight uniquely designed instrumented capsules (which contained refractory metal specimens) operated at an irradiation temperature between 1290 and 1500 K. Temperatures within {plus}/{minus}10 K of target were maintained in seven of the eight capsules during the 335-day irradiation. Data obtained during the experiment clearly showed the advantages of having a temperature control system for high-temperature irradiation capsules. 7 refs., 6 figs., 1 tab.

  17. 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.

  18. 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

  19. 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.}

  20. 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.

  1. A conceptual design tool for RBCC engine performance analysis

    NASA Astrophysics Data System (ADS)

    Olds, John R.; Saks, Greg

    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'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.

  2. 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.

  3. Performance Analysis of Intelligent Robust Facility Layout Design

    NASA Astrophysics Data System (ADS)

    Moslemipour, G.; Lee, T. S.; Loong, Y. T.

    2017-03-01

    Design of a robust production facility layout with minimum handling cost (MHC) presents an appropriate approach to tackle facility layout problems in a dynamic volatile environment, in which product demands randomly change in each planning period. The objective of the design is to find the robust facility layout with minimum total material handling cost over the entire multi-period planning horizon. This paper proposes a new mathematical model for designing robust machine layout in the stochastic dynamic environment of manufacturing systems using quadratic assignment problem (QAP) formulation. In this investigation, product demands are assumed to be normally distributed random variables with known expected value, variance, and covariance that randomly change from period to period. The proposed model was verified and validated using randomly generated numerical data and benchmark examples. The effect of dependent product demands and varying interest rate on the total cost function of the proposed model has also been investigated. Sensitivity analysis on the proposed model has been performed. Dynamic programming and simulated annealing optimization algorithms were used in solving the modeled example problems.

  4. Design validation and performance of closed loop gas recirculation system

    NASA Astrophysics Data System (ADS)

    Kalmani, S. D.; Joshi, A. V.; Majumder, G.; Mondal, N. K.; Shinde, R. R.

    2016-11-01

    A pilot experimental set up of the India Based Neutrino Observatory's ICAL detector has been operational for the last 4 years at TIFR, Mumbai. Twelve glass RPC detectors of size 2 × 2 m2, with a gas gap of 2 mm are under test in a closed loop gas recirculation system. These RPCs are continuously purged individually, with a gas mixture of R134a (C2H2F4), isobutane (iC4H10) and sulphur hexafluoride (SF6) at a steady rate of 360 ml/h to maintain about one volume change a day. To economize gas mixture consumption and to reduce the effluents from being released into the atmosphere, a closed loop system has been designed, fabricated and installed at TIFR. The pressure and flow rate in the loop is controlled by mass flow controllers and pressure transmitters. The performance and integrity of RPCs in the pilot experimental set up is being monitored to assess the effect of periodic fluctuation and transients in atmospheric pressure and temperature, room pressure variation, flow pulsations, uniformity of gas distribution and power failures. The capability of closed loop gas recirculation system to respond to these changes is also studied. The conclusions from the above experiment are presented. The validations of the first design considerations and subsequent modifications have provided improved guidelines for the future design of the engineering module gas system.

  5. 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…

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Rational Design of Protein C Activators

    PubMed Central

    Barranco-Medina, Sergio; Murphy, Mary; Pelc, Leslie; Chen, Zhiwei; Di Cera, Enrico; Pozzi, Nicola

    2017-01-01

    In addition to its procoagulant and proinflammatory functions mediated by cleavage of fibrinogen and PAR1, the trypsin-like protease thrombin activates the anticoagulant protein C in a reaction that requires the cofactor thrombomodulin and the endothelial protein C receptor. Once in the circulation, activated protein C functions as an anticoagulant, anti-inflammatory and regenerative factor. Hence, availability of a protein C activator would afford a therapeutic for patients suffering from thrombotic disorders and a diagnostic tool for monitoring the level of protein C in plasma. Here, we present a fusion protein where thrombin and the EGF456 domain of thrombomodulin are connected through a peptide linker. The fusion protein recapitulates the functional and structural properties of the thrombin-thrombomodulin complex, prolongs the clotting time by generating pharmacological quantities of activated protein C and effectively diagnoses protein C deficiency in human plasma. Notably, these functions do not require exogenous thrombomodulin, unlike other anticoagulant thrombin derivatives engineered to date. These features make the fusion protein an innovative step toward the development of protein C activators of clinical and diagnostic relevance. PMID:28294177

  11. Water-line design and performance of Z

    SciTech Connect

    Garcia, R.J.; Ives, H.C.; Struve, K.W.; Spielman, R.B.; Martin, T.H.; Horry, M.L.; Waverick, R.; Jaramillo, T.F.

    1997-06-01

    A new set of bi-plate transmission lines have been designed and installed in the water-section of PBFA-II for the Z-pinch experiments. Thirty-six aluminum flat-plate transmission lines submerged in a water dielectric deliver a timed electrical pulse from coaxial tube sections to a ring stack section. Each of the lines are electrically isolated from each other by transit-time effects. The water-lines are configured radially at four vertical levels. Each level has nine sets of bi-plates, with a transition section that is unique to that level. Mechanically, the bi-plate sections are designed to carry both static and dynamic loads. Electrically, the lines are designed to transport electrical pulses that average 200 nanoseconds with peak voltage of 2.5 to 3.0 MV. The peak fields exceed 200kV/cm. All line sections are a series of chromate coated aluminum plates, broken down into short, light weight sections. The design of the plates was meticulously developed using the Electro code for voltage break down, and NISA for mechanical analysis. Electrical losses associated with impedance mismatching and voltage breakdown were carefully reviewed. Changes in the bi-plate gap, surface shapes and electrical path discontinuities (mechanical joints) were precisely calculated to achieve maximum electrical performance and reliability. Several iterations of surface shapes and line gaps were reviewed to achieve the most desirable characteristics possible. Additional criteria required that minimal time and effort be required to remove and install the water-lines. Special hardware was developed to help meet this requirement.

  12. 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…

  13. Physical Activity Predicts Performance in an Unpracticed Bimanual Coordination Task

    PubMed Central

    Boisgontier, Matthieu P.; Serbruyns, Leen; Swinnen, Stephan P.

    2017-01-01

    Practice of a given physical activity is known to improve the motor skills related to this activity. However, whether unrelated skills are also improved is still unclear. To test the impact of physical activity on an unpracticed motor task, 26 young adults completed the international physical activity questionnaire and performed a bimanual coordination task they had never practiced before. Results showed that higher total physical activity predicted higher performance in the bimanual task, controlling for multiple factors such as age, physical inactivity, music practice, and computer games practice. Linear mixed models allowed this effect of physical activity to be generalized to a large population of bimanual coordination conditions. This finding runs counter to the notion that generalized motor abilities do not exist and supports the existence of a “learning to learn” skill that could be improved through physical activity and that impacts performance in tasks that are not necessarily related to the practiced activity. PMID:28265253

  14. 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

  15. 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…

  16. Design and performance of the EO-1 Advanced Land Imager

    NASA Astrophysics Data System (ADS)

    Lencioni, Donald E.; Digenis, Constantine J.; Bicknell, William E.; Hearn, David R.; Mendenhall, Jeffrey A.

    1999-12-01

    An Advanced Land Imager (ALI) will be flown on the first Earth Observing mission (EO-1) under NASA's New Millennium Program (NMP). The ALI contains a number of key NMP technologies. These include a 15 degree wide field-of-view, push-broom instrument architecture with a 12.5 cm aperture diameter, compact multispectral detector arrays, non-cryogenic HgCdTe for the short wave infrared bands, silicon carbide optics, and a multi-level solar calibration technique. The focal plane contains multispectral and panchromatic (MS/Pan) detector arrays with a total of 10 spectral bands spanning the 0.4 to 2.5 micrometer wavelength region. Seven of these correspond to the heritage Landsat bands. The instantaneous fields of view of the detectors are 14.2 (mu) rad for the Pan band and 42.6 (mu) rad for the MS bands. The partially populated focal plane provides a 3 degree cross-track coverage corresponding to 37 km on the ground. The focal plane temperature is maintained at 220 K by means of a passive radiator. The instrument environmental and performance testing has been completed. Preliminary data analysis indicates excellent performance. This paper presents an overview of the instrument design, the calibration strategy, and results of the pre-flight performance measurements. It also discusses the potential impact of ALI technologies to future Landsat-like instruments.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. Advances in the Design of High-Performance Flow Control

    NASA Astrophysics Data System (ADS)

    Chen, Kevin K.

    This thesis tackles challenges in feedback control design for fluid flows, from multiple angles and approaches. It covers three major facets---stability theory, control, and reduced-order modeling---and it investigates three major challenges of these facets: nonlinearity, high dimensionality, and non-normality. The dissertation begins with a discussion of global stability via linearized Navier--Stokes eigendecompositions, including numerical algorithms for this analysis. This section then investigates the global stability of a pipe flow through a T-shaped bifurcation at mid-hundred Reynolds numbers, which exhibits vortex breakdown. The recirculation and sensitivity regions closely coincide, which we explain using an inviscid short-wavelength perturbation theory. We also discuss the stability and receptivity properties of this flow. The second part discusses feedback control design for fluid flows, including optimal actuator and sensor placement. It presents an algorithm that computes the gradient of a control measure with respect to such placements, allowing an efficient gradient-based optimization. The implementation on the linearized Ginzburg--Landau and the Orr--Sommerfeld/Squire models of fluid flow reveals that common methods for placement, such as global mode analysis, are suboptimal. We discuss heuristics, including sensitivity, that may predict optimal placements. The third part covers reduced-order flow modeling. It examines previously unknown properties of dynamic mode decomposition (DMD)---a data-based modeling technique---including the uniqueness of the numerical algorithm and the boundary conditions of DMD-based models. We also propose an "optimized" DMD that produces less spurious decompositions, and gives the user control over the number of output modes. We show examples from the two-dimensional laminar flow over a cylinder. This part also investigates the stability and performance of high dimensional (e.g., fluid) systems in closed-loop with reduced

  4. Design of the Active Elevon Rotor for Low Vibration

    NASA Technical Reports Server (NTRS)

    Fulton, Mark V.; Rutkowski, Michael (Technical Monitor)

    2000-01-01

    Helicopter fuselages vibrate more than desired, and traditional solutions have limited effectiveness and can impose an appreciable weight penalty. Alternative methods of combating high vibration, including Higher Harmonic Control (HHC) via harmonic swashplate motion and Individual Blade Control (IBC) via active pitch links, have been studied for several decades. HHC via an on-blade control surface was tested in 1977 on a full scale rotor using a secondary active swashplate and a mechanical control system. Recent smart material advances have prompted new research into the use of on-blade control concepts. Recent analytical studies have indicated that the use of on-blade control surfaces produces vibration reduction comparable to swashplate-based HHC but for less power. Furthermore, smart materials (such as piezoceramics) have been shown to provide sufficient control authority for preliminary rotor experiments. These experiments were initially performed at small scale for reduced tip speeds. More recent experiments have been conducted at or near full tip speeds, and a full-scale active rotor is under development by Boeing with Eurocopter et al. pursuing a similarly advanced full-scale implementation. The US Army Aeroflightdynamics Directorate has undertaken a new research program called the Active Elevon Rotor (AER) Focus Demo. This program includes the design, fabrication, and wind. tunnel testing of a four-bladed, 12.96 ft diameter rotor with one or two on-blade elevons per blade. The rotor, which will be Mach scaled, will use 2-5/rev elevon motion for closed-loop control and :will be tested in late 2001. The primary goal of the AER Focus Demo is the reduction of vibratory hub loads by 80% and the reduction of vibratory blade structural loads. A secondary goal is the reduction of rotor power. The third priority is the measurement and possible reduction of Blade Vortex Interaction (BVI) noise. The present study is focused on elevon effectiveness, that is, the elevon

  5. Molecular design, crystal packing and TFT performance of novel polythiophenes

    NASA Astrophysics Data System (ADS)

    Pan, Hualong

    This thesis presents the design, synthesis and thin-film-transistor performance of a novel series of polythiophenes. The work can be divided into two parts: (1) study of crystal packing of the alkyl side chains in single crystals of model oligothiophene compounds for soluble polythiophenes; (2) exploration of a new series of polythiophenes to achieve favorable crystal packing and hense high mobility for use in organic thin-film-transistors. The first part is based on the crystal packing of a series of compounds derived from the monomer of a high-performance semiconductor, poly(3,3"didodecylquarter-thiophene), PQT-12. A unique conformational polymorphism arising from side chains was observed when the conjugation of backbone of PQT-monomer was extended with phenyl, methyl-phenyl, trifluoromethyl-phenyl. The alkyl side chains preferred tilting towards the middle and then being parallel with the backbones when crystallized from a poor solvent, whereas, the side chains extended out vertically to the backbones when crystallized from a good solvent. The conformational polymorphism of the side chains in the dip-coated film was also studied. The following chapters focus on the design, characterization and TFT performance test of novel polymer semiconductors. A novel and symmetrical poly(4,8-didodecylbenzo[1,2-b:4,5-b']dithiophene) with alkyl side chains tethered to the middle of the large fused backbone was synthesized from 2,6-dibromo-4,8-didodecylbenzo[1,2-b:4,5-b']dithiophene by a dehalogenative coupling polymerization. The thin-film transistors made from this polymer as a semiconductor produced a field-effect mobility of 0.012 cm2V-1s-1 and current on/off ratio ˜2.5x105 after thermal annealing at 140°C. The performance was greatly enhanced (field-effect mobility ˜0.15 cm 2V-1s-1 and current on/off ratio x10 6) when two 3-methyl-thienylenes were incorporated into the backbone, poly(4,8-dodecyl-2,6-bis-(3-methylthiophen-2-yl)-benzo[1,2-b:4,5-b']dithiophene). Such good

  6. Design and development of an active Gurney flap for rotorcraft

    NASA Astrophysics Data System (ADS)

    Freire Gómez, Jon; Booker, Julian D.; Mellor, Phil H.

    2013-03-01

    The EU's Green Rotorcraft programme will develop an Active Gurney Flap (AGF) for a full-scale helicopter main rotor blade as part of its `smart adaptive rotor blade' technology demonstrators. AGFs can be utilized to provide a localized and variable lift enhancement on the rotor, enabling a redistribution of loading on the rotor blade around the rotor azimuth. Further advantages include the possibility of using AGFs to allow a rotor speed reduction, which subsequently provides acoustic benefits. Designed to be integrable into a commercial helicopter blade, and thereby capable of withstanding real in-flight centrifugal loading, blade vibrations and aerodynamic loads, the demonstrator is expected to achieve a high technology readiness level (TRL). The AGF will be validated initially by a constant blade section 2D wind tunnel test and latterly by full blade 3D whirl tower testing. This paper presents the methodology adopted for the AGF concept topology selection, based on a series of both qualitative and quantitative performance criteria. Two different AGF candidate mechanisms are compared, both powered by a small commercial electromagnetic actuator. In both topologies, the link between the actuator and the control surface consists of two rotating torque bars, pivoting on flexure bearings. This provides the required reliability and precision, while making the design virtually frictionless. The engineering analysis presented suggests that both candidates would perform satisfactorily in a 2D wind tunnel test, but that equally, both have design constraints which limit their potential to be further taken into a whirl tower test under full scale centrifugal and inertial loads.

  7. Designing and testing the activities of TAL effector nucleases.

    PubMed

    Lin, Yanni; Cradick, Thomas J; Bao, Gang

    2014-01-01

    Transcription activator-like effector nucleases (TALENs) have rapidly developed into a powerful tool for genome editing. To avoid labor-intensive and time-consuming experimental screening for active TALENs, a scoring system can help select optimal target sites. Here we describe a procedure to design active TALENs using a scoring system named Scoring Algorithm for Predicted TALEN Activity (SAPTA) and a method to test the activity of individual and pairs of TALENs.

  8. Design and implementation of active members for precision space structures

    NASA Technical Reports Server (NTRS)

    Webster, M. S.; Fanson, J. L.; Lurie, B. J.; O'Brien, J. F.

    1992-01-01

    This paper describes the development and implementation of an active member in a precision truss structure. The active member utilizes a piezoelectric actuator motor imbedded in a steel case with built-in displacement sensor. This active member is used in structural quieting. Collocated active damping control loops are designed in order to impedance match piezoelectric active members to the structure. Results from application of these controllers and actuators to the JPL Phase B testbed are given.

  9. 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.

  10. Performance of active vibration control technology: the ACTEX flight experiments

    NASA Astrophysics Data System (ADS)

    Nye, T. W.; Manning, R. A.; Qassim, K.

    1999-12-01

    This paper discusses the development and results of two intelligent structures space-flight experiments, each of which could affect architecture designs of future spacecraft. The first, the advanced controls technology experiment I (ACTEX I), is a variable stiffness tripod structure riding as a secondary payload on a classified spacecraft. It has been operating well past its expected life since becoming operational in 1996. Over 60 on-orbit experiments have been run on the ACTEX I flight experiment. These experiments form the basis for in-space controller design problems and for concluding lifetime/reliability data on the active control components. Transfer functions taken during the life of ACTEX I have shown consistent predictability and stability in structural behavior, including consistency with those measurements taken on the ground prior to a three year storage period and the launch event. ACTEX I can change its modal characteristics by employing its dynamic change mechanism that varies preloads in portions of its structure. Active control experiments have demonstrated maximum vibration reductions of 29 dB and 16 dB in the first two variable modes of the system, while operating over a remarkable on-orbit temperature range of -80 °C to 129 °C. The second experiment, ACTEX II, was successfully designed, ground-tested, and integrated on an experimental Department of Defense satellite prior to its loss during a launch vehicle failure in 1995. ACTEX II also had variable modal behavior by virtue of a two-axis gimbal and added challenges of structural flexibility by being a large deployable appendage. Although the loss of ACTEX II did not provide space environment experience, ground testing resulted in space qualifying the hardware and demonstrated 21 dB, 14 dB, and 8 dB reductions in amplitude of the first three primary structural modes. ACTEX II could use either active and/or passive techniques to affect vibration suppression. Both experiments trailblazed

  11. The role of institutional design and organizational practice for health financing performance and universal coverage.

    PubMed

    Mathauer, Inke; Carrin, Guy

    2011-03-01

    Many low- and middle income countries heavily rely on out-of-pocket health care expenditure. The challenge for these countries is how to modify their health financing system in order to achieve universal coverage. This paper proposes an analytical framework for undertaking a systematic review of a health financing system and its performance on the basis of which to identify adequate changes to enhance the move towards universal coverage. The distinctive characteristic of this framework is the focus on institutional design and organizational practice of health financing, on which health financing performance is contingent. Institutional design is understood as formal rules, namely legal and regulatory provisions relating to health financing; organizational practice refers to the way organizational actors implement and comply with these rules. Health financing performance is operationalized into nine generic health financing performance indicators. Inadequate performance can be caused by six types of bottlenecks in institutional design and organizational practice. Accordingly, six types of improvement measures are proposed to address these bottlenecks. The institutional design and organizational practice of a health financing system can be actively developed, modified or strengthened. By understanding the incentive environment within a health financing system, the potential impacts of the proposed changes can be anticipated.

  12. 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.

  13. Alcohol/ether separation by pervaporation. High performance membrane design

    SciTech Connect

    Roizard, D.; Jonquieres, A.; Leger, C.

    1999-02-01

    Several routes were investigated to design high performance membranes for the separation of tert-butyl ethers (octane enhancers) from alcohols by pervaporation. These routes aim at incorporating Lewis base groups into good film-forming polymers with different structures. The Lewis base groups showed a high affinity to alcohols in screening tests, thus imparting high pervaporation selectivity to the polymer materials. They led to several membranes able to extract pure ethanol out of the azeotropic mixture, but with very low permeation rates. Further modifications of the polymer structure allowed the authors to synthesize materials with greatly enhanced transfer rates and with acceptable selectivity for industrial applications. Structure-property relationships were derived from sorption and pervaporation data for a qualitative prediction of the effect of polymer structure on the flux and selectivity. For these solvent-polymer systems the diffusion phenomenon appears to further improve the pervaporation selectivity for alcohol compared with that given by the sorption process at the membrane face.

  14. 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.

  15. 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.

  16. Application of an optimization method to high performance propeller designs

    NASA Technical Reports Server (NTRS)

    Li, K. C.; Stefko, G. L.

    1984-01-01

    The application of an optimization method to determine the propeller blade twist distribution which maximizes propeller efficiency is presented. The optimization employs a previously developed method which has been improved to include the effects of blade drag, camber and thickness. Before the optimization portion of the computer code is used, comparisons of calculated propeller efficiencies and power coefficients are made with experimental data for one NACA propeller at Mach numbers in the range of 0.24 to 0.50 and another NACA propeller at a Mach number of 0.71 to validate the propeller aerodynamic analysis portion of the computer code. Then comparisons of calculated propeller efficiencies for the optimized and the original propellers show the benefits of the optimization method in improving propeller performance. This method can be applied to the aerodynamic design of propellers having straight, swept, or nonplanar propeller blades.

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

    NASA Technical Reports Server (NTRS)

    Teverovsky, Alexander

    2017-01-01

    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.

  18. 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.

  19. Modeling and design aspects of active caloric regenerators

    NASA Astrophysics Data System (ADS)

    Engelbrecht, Kurt

    2015-03-01

    A cooling device based on a solid caloric material using, for example, the elastocaloric, magnetocaloric, barocaloric or electrocaloric effect has the potential to replace vapor-compression based systems for a variety of applications. Any caloric device using a solid refrigerant may benefit from using a regenerative cycle to increase the operating temperature span. This presentation shows how all active caloric regenerators can be modeled using similar techniques and how they are related to passive regenerator performance. The advantages and disadvantages of using a regenerative cycle are also discussed. The issue of hysteresis in caloric materials is investigated from a system/thermodynamic standpoint and the effects on cooling power and efficiency are quantified using a numerical model of an active regenerator using model caloric materials with assumed properties. The implementation in a working device will be discussed for elastocaloric and magnetocaloric cooling devices. It is shown that demagnetization effects for magnetocaloric systems and stress concentration effects in elastocaloric system reduce the overall effect in the regenerator and care must be taken in regenerator design for both technologies. Other loss mechanisms outside the regenerator such as heat leaks are also discussed. Finally, experimental results for active magnetic regenerative cooler are given for a range of operating conditions. The most recently published device uses a regenerator consisting of Gd and three alloys of GdY and has demonstrated a COP over 3.

  20. Custom design in lower limb prosthetics for athletic activity.

    PubMed

    Fergason, J R; Boone, D A

    2000-08-01

    In summary, the prosthetist is the best source of information with regard to the fast-changing lower extremity prosthetics technology for sports. The needs and desires of the amputee should be outlined and balanced with the cost of the desired components and design. In many cases, one carefully designed prosthesis can serve in dual roles for everyday ambulation and certain athletic activities. In other cases, the amputee is limited severely by a prosthesis that is not designed for a specific activity. Using a prosthesis for activities that it was not designed to accommodate can cause physical injury to the amputee as well as structural failure of the device. A properly designed and fitted prosthesis can open a whole new world of activity to the amputee and helps him or her to reach the desired a vocational goals.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  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. NiTi-Enabled Composite Design for Exceptional Performances

    NASA Astrophysics Data System (ADS)

    Shao, Yang; Guo, Fangmin; Ren, Yang; Zhang, Junsong; Yang, Hong; Jiang, Daqiang; Hao, Shijie; Cui, Lishan

    2017-03-01

    In an effort to further develop shape memory alloys (SMAs) for functional applications, much focus has been given in recent years to design and create innovative forms of SMAs, such as functionally graded SMAs, architecture SMAs, and SMA-based metallic composites. This paper reports on the progress in creating NiTi-based composites of exceptional properties stimulated by the recent discovery of the principle of lattice strain matching between the SMA matrix and superelastic nanoinclusions embedded in the matrix. Based on this principle, different SMA-metal composites have been designed to achieve extraordinary shape memory performances, such as complete pseudoelastic behavior at as low as 77 K and stress plateau as high as 1600 MPa, and exceptional mechanical properties, such as tensile strength as high as 2000 MPa and Young's modulus as low as 28 GPa. Details are given for a NiTi-W micro-fiber composite prepared by melt infiltration, hot pressing, forging, and cold rolling. The composite contained 63% in volume of W micro-fibers of 0.6 μm thickness. In situ synchrotron X-ray diffraction revealed that the NiTi matrix underwent martensite transformation during tensile deformation while the W micro-fiber deformed elastically with a maximum strain of 0.83% in the loading direction, implying a W fiber stress of 3280 MPa. The composite showed a maximum high tensile strength of 2300 MPa.

  7. 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

  8. Aerosol Polarimetry Sensor (APS): Design Summary, Performance and Potential Modifications

    NASA Technical Reports Server (NTRS)

    Cairns, Brian

    2014-01-01

    APS is a mature design that has already been built and has a TRL of 7. Algorithmic and retrieval capabilities continue to improve and make better and more sophisticated used of the data. Adjoint solutions, both in one dimensional and three dimensional are computationally efficient and should be the preferred implementation for the calculation of Jacobians (one dimensional), or cost-function gradients (three dimensional). Adjoint solutions necessarily provide resolution of internal fields and simplify incorporation of active measurements in retrievals, which will be necessary for a future ACE mission. Its best to test these capabilities when you know the answer: OSSEs that are well constrained observationally provide the best place to test future multi-instrument platform capabilities and ensure capabilities will meet scientific needs.

  9. 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.

  10. 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.

  11. High-performance computing in accelerating structure design and analysis

    NASA Astrophysics Data System (ADS)

    Li, Zenghai; Folwell, Nathan; Ge, Lixin; Guetz, Adam; Ivanov, Valentin; Kowalski, Marc; Lee, Lie-Quan; Ng, Cho-Kuen; Schussman, Greg; Stingelin, Lukas; Uplenchwar, Ravindra; Wolf, Michael; Xiao, Liling; Ko, Kwok

    2006-03-01

    Future high-energy accelerators such as the Next Linear Collider (NLC) will accelerate multi-bunch beams of high current and low emittance to obtain high luminosity, which put stringent requirements on the accelerating structures for efficiency and beam stability. While numerical modeling has been quite standard in accelerator R&D, designing the NLC accelerating structure required a new simulation capability because of the geometric complexity and level of accuracy involved. Under the US DOE Advanced Computing initiatives (first the Grand Challenge and now SciDAC), SLAC has developed a suite of electromagnetic codes based on unstructured grids and utilizing high-performance computing to provide an advanced tool for modeling structures at accuracies and scales previously not possible. This paper will discuss the code development and computational science research (e.g. domain decomposition, scalable eigensolvers, adaptive mesh refinement) that have enabled the large-scale simulations needed for meeting the computational challenges posed by the NLC as well as projects such as the PEP-II and RIA. Numerical results will be presented to show how high-performance computing has made a qualitative improvement in accelerator structure modeling for these accelerators, either at the component level (single cell optimization), or on the scale of an entire structure (beam heating and long-range wakefields).

  12. High-Performance Computing in Accelerating Structure Design And Analysis

    SciTech Connect

    Li, Z.H.; Folwell, N.; Ge, Li-Xin; Guetz, A.; Ivanov, V.; Kowalski, M.; Lee, L.Q.; Ng, C.K.; Schussman, G.; Stingelin, L.; Uplenchwar, R.; Wolf, M.; Xiao, L.L.; Ko, K.; /SLAC /PSI, Villigen /Illinois U., Urbana

    2006-06-27

    Future high-energy accelerators such as the Next Linear Collider (NLC) will accelerate multi-bunch beams of high current and low emittance to obtain high luminosity, which put stringent requirements on the accelerating structures for efficiency and beam stability. While numerical modeling has been quite standard in accelerator R&D, designing the NLC accelerating structure required a new simulation capability because of the geometric complexity and level of accuracy involved. Under the US DOE Advanced Computing initiatives (first the Grand Challenge and now SciDAC), SLAC has developed a suite of electromagnetic codes based on unstructured grids and utilizing high performance computing to provide an advanced tool for modeling structures at accuracies and scales previously not possible. This paper will discuss the code development and computational science research (e.g. domain decomposition, scalable eigensolvers, adaptive mesh refinement) that have enabled the large-scale simulations needed for meeting the computational challenges posed by the NLC as well as projects such as the PEP-II and RIA. Numerical results will be presented to show how high performance computing has made a qualitative improvement in accelerator structure modeling for these accelerators, either at the component level (single cell optimization), or on the scale of an entire structure (beam heating and long range wakefields).

  13. 40 CFR Table 6 to Subpart Wwww of... - Basic Requirements for Performance Tests, Performance Evaluations, and Design Evaluations for New...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Tests, Performance Evaluations, and Design Evaluations for New and Existing Sources Using Add-On Control... Performance Tests, Performance Evaluations, and Design Evaluations for New and Existing Sources Using Add-On... emissions to an add-on control device that is a PTE Meet the requirements for a PTE EPA method 204...

  14. 40 CFR Table 6 to Subpart Wwww of... - Basic Requirements for Performance Tests, Performance Evaluations, and Design Evaluations for New...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Tests, Performance Evaluations, and Design Evaluations for New and Existing Sources Using Add-On Control... Performance Tests, Performance Evaluations, and Design Evaluations for New and Existing Sources Using Add-On... emissions to an add-on control device that is a PTE Meet the requirements for a PTE EPA method 204...

  15. 40 CFR Table 6 to Subpart Wwww of... - Basic Requirements for Performance Tests, Performance Evaluations, and Design Evaluations for New...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Tests, Performance Evaluations, and Design Evaluations for New and Existing Sources Using Add-On Control... Performance Tests, Performance Evaluations, and Design Evaluations for New and Existing Sources Using Add-On... emissions to an add-on control device that is a PTE Meet the requirements for a PTE EPA method 204...

  16. 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

  17. Improving the performances of current optical interferometers & future designs

    NASA Astrophysics Data System (ADS)

    Arnold, L.; Le Coroller, H.; Surdej, J.

    2014-04-01

    The number of astrophysical studies making use of interferometers has steadily increased during the past 15 years. Nevertheless, the performances of interferometers are still limited: their sensitivity does not exceed magnitude V=12, and their imaging capability could yet be improved by increasing the number of telescopes/sub-apertures. In the context of the ELTs, it is not certain how future interferometry projects will be financed. However, interferometry remains the only way to observe compact astrophysical objects at very high angular resolution (< milli-arcsecond), like gravitational micro-lensing events, central engines of AGNs, proto-planetary disks, exoplanets, etc. The aim of this workshop was to review and discuss the development of technologies that could improve the performances of current and future interferometers: new optical designs; techniques to improve the accuracy of measurements (visibility, closure-phase, etc.); progress on delay-line performances; solutions without delay-lines; technologies for larger apertures at lower cost (ex: lightweight replica mirrors); optimized beam combiners (integrated optic, pupil densifier, etc.); fringe tracking systems; laser telemetry applied to interferometry; heterodyne interferometry; progress in heterodyne detection using new technologies (laser comb, time propagation technologies, etc.); progress in image reconstruction techniques; progress in nulling interferometry; and important science cases that could benefit from progress in interferometry (report of observations at the limit of current interferometers). Nearly 50 oral presentations have been delivered, followed by very lively discussions which eventually emerged with the proposition to organize the "Planet Formation Interferometer/Imager" (PFI) project. The present proceedings reflect most of the highlights of this international colloquium.

  18. Comparing Fish Screen Performance to Physical Design Criteria

    SciTech Connect

    McMichael, Geoffrey A.; Vucelick, Jessica A.; Abernethy, Cary S.; Neitzel, Duane A.

    2004-07-01

    Fish screens associated with irrigation diversion structures in streams where salmonids are present can perform a vital function by protecting rearing and migrating fishes. Irrigation diversions in the western United States were developed in the late 1800?s and early 1900?s with little regard to how they might affect fish populations. Fish screens were installed on some diversions beginning in the 1930's but were often ineffective. Beginning in the 1980's a ''modern-era'' fish screening program was initiated in the Yakima River basin in Washington State. A systematic phased approach was employed, with federal funding, to replace antiquated screens and to install screens where there had not previously been any. Also during this time, the federal and state agencies responsible for protecting the fish resources developed criteria to guide the design of these facilities. These criteria, developed by the National Oceanic and Atmospheric Agency Fisheries (formerly the National Marine Fisheries Service) and adopted by the Washington Department of Fish and Wildlife, dictate the limits of physical metrics such as approach velocity for fish screens facilities. To determine whether the investment in fish screen facilities were paying dividends in terms of the fish protection they were designed and built to achieve, the in-situ evaluation of these facilities was required. Scientists at the Pacific Northwest National Laboratory (PNNL) developed methods for evaluating these new fish screen facilities as they came ''on-line'' to document whether the facilities were designed, constructed, operated and maintained to be within the fish passage criteria. Because the fish protection criteria were developed to guide facility engineering and design, researchers had to interpret the criteria in terms of how they would be applied to data from the field to determine whether a specific facility was operated within criteria. PNNL uses a combination of water velocity measurements, visual

  19. 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.

  20. 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…

  1. Design, modeling and performance of a hybrid portable gamma camera

    NASA Astrophysics Data System (ADS)

    Smith, Leon Eric

    The combination of a mechanically-collimated gamma-ray camera with an electronically-collimated gamma camera offers both the high efficiency and good angular resolution typical in a mechanically-collimated camera for lower photon energies and the uncoupling of spatial resolution and efficiency provided by an electronically-collimated camera at higher energies. The design, construction, performance modeling and measured performance of the Hybrid Portable Gamma Camera (HPGC) are presented here. Intended for industrial use, the HPGC offers good angular resolution and efficiency over a broad energy range (50 keV to 2 MeV) by combining a MURA coded aperture camera with a Compton scatter camera in a single system. The HPGC consists of two detector modules: (1) a NaI(Tl) scintillator with Anger logic readout and (2) a CsI(Na) pixellated crystal viewed by a position-sensitive photomultiplier tube. Analytical calculations of angular resolution components and efficiency for the HPGC were compared to Monte Carlo calculations of the same quantities. The predicted angular resolution performance for on-axis point sources, a central scattering angle of 45sp° and a detector separation distance of 35 cm ranges from 3.5-6sp° FWHM over the sensitive energy range. The mechanical collimation intrinsic efficiency for energies up to 800 keV varies from 0.50 to 0.05 while the electronic collimation intrinsic efficiency for energies above 400 keV is 7.0×10sp{-4} to 5×10sp{-5}. The experimentally measured angular resolution and efficiency values show good agreement with the modeling predictions for incident energies of 412 keV and 662 keV. Although work has been done on mechanical collimation cameras and electronic collimation cameras operating independently, no truly hybrid imaging system has been constructed that uses the same gamma ray for both mechanical collimation and electronic collimation information. This dissertation compares the relative information per photon for three

  2. 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.

  3. 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.

  4. Design of a three-dimensional multitarget activity landscape.

    PubMed

    de la Vega de León, Antonio; Bajorath, Jürgen

    2012-11-26

    The design of activity landscape representations is challenging when compounds are active against multiple targets. Going beyond three or four targets, the complexity of underlying activity spaces is difficult to capture in conventional activity landscape views. Previous attempts to generate multitarget activity landscapes have predominantly utilized extensions of molecular network representations or plots of activity versus chemical similarity for pairs of active compounds. Herein, we introduce a three-dimensional multitarget activity landscape design that is based upon principles of radial coordinate visualization. Circular representations of multitarget activity and chemical reference space are combined to generate a spherical view into which compound sets are projected for interactive analysis. Interpretation of landscape content is facilitated by following three canonical views of activity, chemical, and combined activity/chemical space, respectively. These views focus on different planes of the underlying coordinate system. From the activity and combined views, compounds with well-defined target selectivity and structure-activity profile relationships can be extracted. In the activity landscape, such compounds display characteristic spatial arrangements and target activity patterns.

  5. Design and performance of the Douglas Mawson telescope

    NASA Astrophysics Data System (ADS)

    Lawrence, Jon S.; Ashley, Michael C. B.; Burton, Michael G.; Storey, John W. V.

    2002-12-01

    The Douglas Mawson Telescope (DMT) is a proposed 2 m telescope to be situated on the Antarctic plateau. The proposal comes from Australia, and invites participation by other nations, especially those already active in Antarctic astronomy; such as Italy, France and the United States. The DMT will be equipped with instrumentation to perform wide-field imaging from the near to far infrared. Results from an extensive site testing campaign over the last decade indicates that an Antarctic infrared telescope can be one to two orders of magnitude more sensitive than any other ground based telescope of the same size. The DMT will be an important tool for astrophysical research. It will also be beneficial as a technological test bed for future large (8-10 m class) Antarctic telescopes and interferometers, and for space-based telescopes. This paper analyses the performance of the DMT in terms of the achievable resolution, field-of-view, sensitivity and survey depth and compares it to a similar sized telescope located with the characteristic mid-latitude atmosphere of Mauna Kea.

  6. Design and Analysis of an Active Helical Drive Downhole Tractor

    NASA Astrophysics Data System (ADS)

    LI, Yujia; LIU, Qingyou; CHEN, Yonghua; REN, Tao

    2017-03-01

    During oil-gas well drilling and completion, downhole tools and apparatus should be conveyed to the destination to complete a series of downhole works. Downhole tractors have been used to convey tools in complex wellbores, however a very large tractive force is needed to carry more downhole tools to accomplish works with high efficiency. A novel serial active helical drive downhole tractor which has significantly improved performance compared with previous work is proposed. All previously reported helical drive downhole tractors need stators to balance the torque generated by the rotator. By contrast, the proposed serial downhole tractor does not need a stator; several rotator-driven units should only be connected to one another to achieve a tractive force multifold higher than that was previously reported. As a result, the length of a single unit is shortened, and the motion flexibility of the downhole tractor is increased. The major performance indicators, namely, gear ratio, velocity, and tractive force, are analyzed. Experimental results show that the maximum tractive force of a single-unit prototype with a length of 900 mm is 165.3 kg or 1620 N. The analysis and experimental results show that the proposed design has considerable potential for downhole works.

  7. Integration of Humanitarian Knowledge in Art and Design Activity

    ERIC Educational Resources Information Center

    Kamzina, Nadezhda Enovna; Mazina, Julia Ilyinichna; Turganbayeva, Shakhizada Sainbekovna

    2016-01-01

    The process of integration of humanitarian knowledge is being examined in the article and the development of the project activities and a special outlook on the examples of famous artists, designers and architects are investigated. The forms of creative thinking are systematized and the factors modifying the borders of design knowledge are formed…

  8. 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…

  9. Design and performance of radioisotope space power systems based on OSC multitube AMTEC converter designs

    SciTech Connect

    Schock, A.; Noravian, H.; Or, C.

    1997-12-31

    This paper extends the analytical procedure described in another paper in these proceedings to analyze a variety of compact and light-weight OSC-designed radioisotope-heated generators. Those generators employed General Purpose Heat Source (GPHS) modules and a converter containing sixteen AMTEC cells of OSC`s revised five-tube design with enhanced cell wall reflectivity described in a companion paper in these proceedings. OSC found that the performance of the generator is primarily a function of the thermal insulation between the outside of the generator`s 16 cells and the inside of its wall. After examining a variety of insulation options, it was found that the generator`s performance is optimized by employing a hybrid insulation system, in which the space between the cells is filled with fibrous Min-K insulation, and the generator walls are lined with tapered (i.e., graded-length) multifoil insulation. The OSC design results in a very compact generator, with eight AMTEC cells on each end of the heat source stack. The choice of the five-tube cells makes it possible to expand the BASE tube diameter without increasing the cell diameter. This is important because the eight cells mate well with the stacked GPHS modules. The OSC generator design includes a compliant heat source support and preload arrangement, to hold the heat source modules together during launch, and to maintain thermal contact conductance at the generator`s interfaces despite creep relaxation of its housing. The BOM and EOM (up to 15 years) performances of the revised generators were analyzed for two and three GPHS modules, both for fresh fuel and for aged fuel left over from a spare RTG (Radioisotope Thermoelectric Generator) fueled in 1982. The resulting power outputs were compared with JPL`s latest EOM power demand goals for the Pluto Express and Europa Orbiter missions, and with the generic goals of DOE`s Advanced Radioisotope Power System (ARPS) study. The OSC AMTEC designs yielded system

  10. SAPTA: a new design tool for improving TALE nuclease activity.

    PubMed

    Lin, Yanni; Fine, Eli J; Zheng, Zhilan; Antico, Christopher J; Voit, Richard A; Porteus, Matthew H; Cradick, Thomas J; Bao, Gang

    2014-04-01

    Transcription activator-like effector nucleases (TALENs) have become a powerful tool for genome editing due to the simple code linking the amino acid sequences of their DNA-binding domains to TALEN nucleotide targets. While the initial TALEN-design guidelines are very useful, user-friendly tools defining optimal TALEN designs for robust genome editing need to be developed. Here we evaluated existing guidelines and developed new design guidelines for TALENs based on 205 TALENs tested, and established the scoring algorithm for predicting TALEN activity (SAPTA) as a new online design tool. For any input gene of interest, SAPTA gives a ranked list of potential TALEN target sites, facilitating the selection of optimal TALEN pairs based on predicted activity. SAPTA-based TALEN designs increased the average intracellular TALEN monomer activity by >3-fold, and resulted in an average endogenous gene-modification frequency of 39% for TALENs containing the repeat variable di-residue NK that favors specificity rather than activity. It is expected that SAPTA will become a useful and flexible tool for designing highly active TALENs for genome-editing applications. SAPTA can be accessed via the website at http://baolab.bme.gatech.edu/Research/BioinformaticTools/TAL_targeter.html.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Design and performance analysis of multilayer nested grazing incidence optics

    NASA Astrophysics Data System (ADS)

    Zuo, Fuchang; Deng, Loulou; Mei, Zhiwu; Li, Liansheng; Lv, Zhengxin

    2014-10-01

    We have developed X-ray grazing incidence optics with a single mirror. Although t can be used to demonstrate and test on the ground to verify the feasibility of X-ray detection system, it is unable to meet the requirements of X-ray pulsar navigation due to small effective area and large mass. There is an urgent need to develop multilayer nested grazing incidence optics, which consists of multilayer mirrors to form a coaxial and confocal system to maximize the use of space and increase the effective area. In this paper, aiming at the future demand of X-ray pulsar navigation, optimization and analysis of nested X-ray grazing incidence optics was carried out, the recurrence relations between the layers of mirrors were derived, reasonable initial structural parameters and stray light reduction method was given, and theoretical effective collection area was calculated. The initial structure and stray light eliminating structure are designed. The optical-mechanical-thermal numerical model was established using optical analysis software and finite element software for stray light analysis, focusing performance analysis, tolerance analysis, and mechanical analysis, providing evidence and guidance for the processing and alignment of nested X-ray grazing incidence optics.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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…

  4. PEGASUS: Designing a System for Supporting Group Activity

    ERIC Educational Resources Information Center

    Kyprianidou, Maria; Demetriadis, Stavros; Pombortsis, Andreas; Karatasios, George

    2009-01-01

    Purpose: The purpose of this paper is to present the design and first results of the integration of a web-based system person-centred group-activity support system (PEGASUS) in university instruction, as a means for advancing person-centred learning by supporting group activity. The PEGASUS is expected to help students and teachers in two distinct…

  5. 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…

  6. 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…

  7. 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.

  8. Systems design of high performance stainless steels I. Conceptual and computational design

    NASA Astrophysics Data System (ADS)

    Campbell, C. E.; Olson, G. B.

    2000-10-01

    Application of a systems approach to the computational materials design led to the development of a high performance stainless steel. The systems approach highlighted the integration of processing/structure/property/ performance relations with mechanistic models to achieve desired quantitative property objectives. The mechanistic models applied to the martensitic transformation behavior included the Olson Cohen model for heterogeneous nucleation and the Ghosh Olson solid-solution strengthening model for interfacial mobility. Strengthening theory employed modeling of the coherent M2C precipitation in a BCC matrix, which is initially in a paraequilibrium with cementite condition. The calibration of the M2C coherency used available small-angle neutron scattering (SANS) data to determine a composition-dependent strain energy and a composition-independent interfacial energy. Multicomponent pH-potential diagrams provided an effective tool for evaluating oxide stability. Constrained equilibrium calculations correlated oxide stability to Cr enrichment in the metastable spinel film, allowing more efficient use of alloy Cr content. The composition constraints acquired from multicomponent solidification simulations improved castability. Then integration of the models, using multicomponent thermodynamic and diffusion software programs, enabled the design of a carburizable, secondary-hardening martensitic stainless steel for advanced bearing applications.

  9. DSN 70-meter antenna microwave optics design and performance improvements. Part 1: Design optimization

    NASA Technical Reports Server (NTRS)

    Bathker, D. A.; Slobin, S. D.

    1989-01-01

    The design optimizations associated with the microwave and structural upgrade of the DSN 64-m antennas are discussed. Expected area efficiency/gain performances at S- and X-band are given for both the original 64-m systems and the upgraded 70-m systems, and error estimates are developed. The DSN 70-m Upgrade Project specifications, based on predesign estimates, were 1.4-dB gain at S-band and 1.9-dB at X-band, with no degradation to critical receiving system noise temperatures. The measurements show an S-band gain increase of 1.9 dB and an average increase of 2.1 dB at X-band. The Project also delivered small receiving system noise decreases at both frequency bands. The three DSN 70-m antennas, in the initial state of mechanical adjustment as of the end of calendar year 1988, are performing with very high peak microwave area efficiencies at very nearly the engineering design expectations of 76 percent at S-band and 71 percent at X-band.

  10. 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.

  11. 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.

  12. 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…

  13. Integrating Computer Architectures into the Design of High-Performance Controllers

    NASA Technical Reports Server (NTRS)

    Jacklin, Stephen A.; Leyland, Jane A.; Warmbrodt, William

    1986-01-01

    Modern control systems must typically perform real-time identification and control, as well as coordinate a host of other activities related to user interaction, on-line graphics, and file management. This paper discusses five global design considerations that are useful to integrate array processor, multimicroprocessor, and host computer system architecture into versatile, high-speed controllers. Such controllers are capable of very high control throughput, and can maintain constant interaction with the non-real-time or user environment. As an application example, the architecture of a high-speed, closed-loop controller used to actively control helicopter vibration will be briefly discussed. Although this system has been designed for use as the controller for real-time rotorcraft dynamics and control studies in a wind-tunnel environment, the control architecture can generally be applied to a wide range of automatic control applications.

  14. Performance in physiology evaluation: possible improvement by active learning strategies.

    PubMed

    Montrezor, Luís H

    2016-12-01

    The evaluation process is complex and extremely important in the teaching/learning process. Evaluations are constantly employed in the classroom to assist students in the learning process and to help teachers improve the teaching process. The use of active methodologies encourages students to participate in the learning process, encourages interaction with their peers, and stimulates thinking about physiological mechanisms. This study examined the performance of medical students on physiology over four semesters with and without active engagement methodologies. Four activities were used: a puzzle, a board game, a debate, and a video. The results show that engaging in activities with active methodologies before a physiology cognitive monitoring test significantly improved student performance compared with not performing the activities. We integrate the use of these methodologies with classic lectures, and this integration appears to improve the teaching/learning process in the discipline of physiology and improves the integration of physiology with cardiology and neurology. In addition, students enjoy the activities and perform better on their evaluations when they use them.

  15. The influence of anodic helical design on fluid flow and bioelectrochemical performance.

    PubMed

    Michie, Iain S; Kim, Jung Rae; Dinsdale, Richard M; Guwy, Alan J; Premier, Giuliano C

    2014-08-01

    In this study three different tubular helical anode designs are compared, for each helical design the pitch and nominal sectional area/liquid flow channel between the helicoids was varied and this produced maximum power densities of 11.63, 9.2 and 6.73Wm(-3) (small, medium and large helical flow channel cross-sections). It is found that the level of mixing and the associated shear rates present in the anodes affects both the power development and biofilm formation. The small helical flow channel carbon anode produced 40% more biofilm and this result was related to modelling data which determined a system shear rate of 237s(-1), compared to 52s(-1) and 47s(-1) for the other reactor configurations. The results from computational fluid dynamic modelling further distinguishes between convective flow conditions and supports the influence of helical structure on system performance, so establishing the importance of anodic design on the overall electrogenic biofilm activity.

  16. 40 CFR Table 6 to Subpart Wwww of... - Basic Requirements for Performance Tests, Performance Evaluations, and Design Evaluations for New...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Tests, Performance Evaluations, and Design Evaluations for New and Existing Sources Using Add-On Control... Tests, Performance Evaluations, and Design Evaluations for New and Existing Sources Using Add-On Control... emissions to an add-on control device that is a PTE Meet the requirements for a PTE EPA method 204...

  17. 40 CFR Table 6 to Subpart Wwww of... - Basic Requirements for Performance Tests, Performance Evaluations, and Design Evaluations for New...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Tests, Performance Evaluations, and Design Evaluations for New and Existing Sources Using Add-On Control... Tests, Performance Evaluations, and Design Evaluations for New and Existing Sources Using Add-On Control... emissions to an add-on control device that is a PTE Meet the requirements for a PTE EPA method 204...

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Human Activity Modeling: Toward A Pragmatic Integration of Activity Theory and Usage-Centered Design

    NASA Astrophysics Data System (ADS)

    Constantine, Larry L.

    Human activity modeling is a systematic approach to organizing and representing the contextual aspects of tool use that is both well-grounded in an accepted theoretical framework and embedded within a proven design method. Activity theory provides the vocabulary and conceptual framework for understanding the human use of tools and other artifacts. Usage-centered design provides the methodological scaffolding for applying activity theory in practice. In this chapter, activity theory and usage-centered design are outlined and the connections between the two are highlighted. Simple extensions to the models of usage-centered design are introduced that together succinctly model the salient and most essential features of the activities within which tool use is embedded. Although not intended as a tutorial, examples of Activity Maps, Activity Profiles, and Participation Maps are provided.

  3. 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…

  4. 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.

  5. 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…

  6. High-performance passive viscous isolator element for active/passive (hybrid) isolation

    NASA Astrophysics Data System (ADS)

    Davis, Torey; Davis, L. Porter; Sullivan, Jeanne M.; Hoffman, Terry; Das, Alok

    1996-05-01

    A high performance passive isolator has been developed for a multiaxis isolation system for vibration isolation of an optical payload. This passive isolator will be used along with an active element to provide improved vibration isolation performance over previous isolators. The isolator has been designed using ideas developed previously for 'tuned' three parameter passive isolators. The isolator has also been developed offering the lowest system passive break frequencies structurally feasible for the lightweight optical payload. The implementations of these passive isolator design considerations complement the active portion of the system, and also provide the best passive isolation at the higher frequencies long after the active system has 'rolled off.' The mathematics used to design the isolator as well as the isolator's physical attributes are discussed. The unique design challenges of incorporating the passive element with the active, forming one 'hybrid' D-strut$TM, also are discussed. Finally, actual test data from isolator testing are compared to predicted performance, verifying the isolator's exceptional performance and predictability.

  7. 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…

  8. Embedded Sensors and Controls to Improve Component Performance and Reliability -- Loop-scale Testbed Design Report

    SciTech Connect

    Melin, Alexander M.; Kisner, Roger A.

    2016-09-01

    Embedded instrumentation and control systems that can operate in extreme environments are challenging to design and operate. Extreme environments limit the options for sensors and actuators and degrade their performance. Because sensors and actuators are necessary for feedback control these limitations mean that designing embedded instrumentation and control systems for the challenging environments of nuclear reactors requires advanced technical solutions that are not available commercially. This report details the development of testbed that will be used for cross-cutting embedded instrumentation and control research for nuclear power applications. This research is funded by the Department of Energy's Nuclear Energy Enabling Technology program's Advanced Sensors and Instrumentation topic. The design goal of the loop-scale testbed is to build a low temperature pump that utilizes magnetic bearing that will be incorporated into a water loop to test control system performance and self-sensing techniques. Specifically, this testbed will be used to analyze control system performance in response to nonlinear and cross-coupling fluid effects between the shaft axes of motion, rotordynamics and gyroscopic effects, and impeller disturbances. This testbed will also be used to characterize the performance losses when using self-sensing position measurement techniques. Active magnetic bearings are a technology that can reduce failures and maintenance costs in nuclear power plants. They are particularly relevant to liquid salt reactors that operate at high temperatures (700 C). Pumps used in the extreme environment of liquid salt reactors provide many engineering challenges that can be overcome with magnetic bearings and their associated embedded instrumentation and control. This report will give details of the mechanical design and electromagnetic design of the loop-scale embedded instrumentation and control testbed.

  9. 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…

  10. 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.

  11. 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...

  12. 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…

  13. CMS Physics Technical Design Report, Volume II: Physics Performance

    NASA Astrophysics Data System (ADS)

    CMS Collaboration

    2007-06-01

    CMS is a general purpose experiment, designed to study the physics of pp collisions at 14 TeV at the Large Hadron Collider (LHC). It currently involves more than 2000 physicists from more than 150 institutes and 37 countries. The LHC will provide extraordinary opportunities for particle physics based on its unprecedented collision energy and luminosity when it begins operation in 2007. The principal aim of this report is to present the strategy of CMS to explore the rich physics programme offered by the LHC. This volume demonstrates the physics capability of the CMS experiment. The prime goals of CMS are to explore physics at the TeV scale and to study the mechanism of electroweak symmetry breaking—through the discovery of the Higgs particle or otherwise. To carry out this task, CMS must be prepared to search for new particles, such as the Higgs boson or supersymmetric partners of the Standard Model particles, from the start-up of the LHC since new physics at the TeV scale may manifest itself with modest data samples of the order of a few fb -1 or less. The analysis tools that have been developed are applied to study in great detail and with all the methodology of performing an analysis on CMS data specific benchmark processes upon which to gauge the performance of CMS. These processes cover several Higgs boson decay channels, the production and decay of new particles such as Z' and supersymmetric particles, B s production and processes in heavy ion collisions. The simulation of these benchmark processes includes subtle effects such as possible detector miscalibration and misalignment. Besides these benchmark processes, the physics reach of CMS is studied for a large number of signatures arising in the Standard Model and also in theories beyond the Standard Model for integrated luminosities ranging from 1 fb -1 to 30 fb -1 . The Standard Model processes include QCD, B -physics, diffraction, detailed studies of the top quark properties, and electroweak physics

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Active cooling for downhole instrumentation: design criteria and conceptual design summary

    SciTech Connect

    Bennett, G.A.

    1986-05-01

    This report summarizes the results of a literature survey that describes successful tests of geophysical instruments and their thermal protection systems. The conditions to which an instrument is subjected are formulated into relevant thermal and mechanical design criteria that have proved useful for improving passive thermal protection systems and selecting the preliminary feasibility of active refrigeration systems. A brief summary of the results of a series of conceptual designs on seven different active refrigeration systems is given. The systems are ranked according to feasibility for use in downhole active cooling applications.

  20. 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.

  1. 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.

  2. Neighborhood Design, Physical Activity, and Wellbeing: Applying the Walkability Model.

    PubMed

    Zuniga-Teran, Adriana A; Orr, Barron J; Gimblett, Randy H; Chalfoun, Nader V; Guertin, David P; Marsh, Stuart E

    2017-01-13

    Neighborhood design affects lifestyle physical activity, and ultimately human wellbeing. There are, however, a limited number of studies that examine neighborhood design types. In this research, we examine four types of neighborhood designs: traditional development, suburban development, enclosed community, and cluster housing development, and assess their level of walkability and their effects on physical activity and wellbeing. We examine significant associations through a questionnaire (n = 486) distributed in Tucson, Arizona using the Walkability Model. Among the tested neighborhood design types, traditional development showed significant associations and the highest value for walkability, as well as for each of the two types of walking (recreation and transportation) representing physical activity. Suburban development showed significant associations and the highest mean values for mental health and wellbeing. Cluster housing showed significant associations and the highest mean value for social interactions with neighbors and for perceived safety from crime. Enclosed community did not obtain the highest means for any wellbeing benefit. The Walkability Model proved useful in identifying the walkability categories associated with physical activity and perceived crime. For example, the experience category was strongly and inversely associated with perceived crime. This study provides empirical evidence of the importance of including vegetation, particularly trees, throughout neighborhoods in order to increase physical activity and wellbeing. Likewise, the results suggest that regular maintenance is an important strategy to improve mental health and overall wellbeing in cities.

  3. Neighborhood Design, Physical Activity, and Wellbeing: Applying the Walkability Model

    PubMed Central

    Zuniga-Teran, Adriana A.; Orr, Barron J.; Gimblett, Randy H.; Chalfoun, Nader V.; Guertin, David P.; Marsh, Stuart E.

    2017-01-01

    Neighborhood design affects lifestyle physical activity, and ultimately human wellbeing. There are, however, a limited number of studies that examine neighborhood design types. In this research, we examine four types of neighborhood designs: traditional development, suburban development, enclosed community, and cluster housing development, and assess their level of walkability and their effects on physical activity and wellbeing. We examine significant associations through a questionnaire (n = 486) distributed in Tucson, Arizona using the Walkability Model. Among the tested neighborhood design types, traditional development showed significant associations and the highest value for walkability, as well as for each of the two types of walking (recreation and transportation) representing physical activity. Suburban development showed significant associations and the highest mean values for mental health and wellbeing. Cluster housing showed significant associations and the highest mean value for social interactions with neighbors and for perceived safety from crime. Enclosed community did not obtain the highest means for any wellbeing benefit. The Walkability Model proved useful in identifying the walkability categories associated with physical activity and perceived crime. For example, the experience category was strongly and inversely associated with perceived crime. This study provides empirical evidence of the importance of including vegetation, particularly trees, throughout neighborhoods in order to increase physical activity and wellbeing. Likewise, the results suggest that regular maintenance is an important strategy to improve mental health and overall wellbeing in cities. PMID:28098785

  4. 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.

  5. The Messenger Spacecraft Power System Design and Early Mission Performance

    NASA Astrophysics Data System (ADS)

    Dakermanji, G.; Person, C.; Jenkins, J.; Kennedy, L.; Temkin, D.

    2005-05-01

    The MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) spacecraft was launched on August 3, 2004. The spacecraft will be inserted into Mercury orbit in March 2011 for one year of orbital operation. During the mission, the spacecraft distance to the Sun will vary between approximately 1 and 0.3 Astronomical Units (AU), imposing severe requirements on the spacecraft thermal and power systems design. The spacecraft is maintained behind a sunshade. The two single-axis, gimbaled solar array panels are designed to withstand the expected high temperatures. A peak power tracking system has been selected to allow operation over the widely varying solar array I-V curves. In order to reduce cost and risk while increasing the likelihood of mission success, the approach taken in the power system design, including the solar arrays, was to use conventional design, materials, and fabrication techniques.

  6. Design, Synthesis, and Antibacterial Activities of Novel Heterocyclic Arylsulphonamide Derivatives.

    PubMed

    Singh, Anuradha; Srivastava, Ritika; Singh, Ramendra K

    2017-02-13

    Design, synthesis, and antibacterial activities of a series of arylsulphonamide derivatives as probable peptide deformylase (PDF) inhibitors have been discussed. Compounds have been designed following Lipinski's rule and after docking into the active site of PDF protein (PDB code: 1G2A) synthesized later on. Furthermore, to assess their antibacterial activity, screening of the compound was done in vitro conditions against Gram-positive and Gram-negative bacterial strains. In silico, studies revealed these compounds as potential antibacterial agents and this fact was also supported by their prominent scoring functions. Antibacterial results indicated that these molecules possessed a significant activity against Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa, and Escherichia coli with MIC values ranging from 0.06 to 0.29 μM. TOPKAT results showed that high LD50 values and the compounds were assumed non-carcinogenic when various animal models were studied computationally.

  7. Design and Performance Optimization of GeoFEST for Adaptive Geophysical Modeling on High Performance Computers

    NASA Astrophysics Data System (ADS)

    Norton, C. D.; Parker, J. W.; Lyzenga, G. A.; Glasscoe, M. T.; Donnellan, A.

    2006-12-01

    The Geophysical Finite Element Simulation Tool (GeoFEST) and the PYRAMID parallel adaptive mesh refinement library have been integrated to provide high performance and high resolution modeling of 3D Earth crustal deformation under tectonic loading associated with the Earthquake cycle. This includes co-seismic and post-seismic modeling capabilities as well as other problems of geophysical interest. The use of the PYRAMID AMR library has allowed simulations of tens of millions of elements on various parallel computers where strain energy is applied as the error estimation criterion. This has allowed for improved generation of time-dependent simulations where the computational effort can be localized to geophysical regions of most activity. This talk will address techniques including conversion of the sequential GeoFEST software to a parallel version using PYRAMID, performance optimization and various lessons learned as part of porting such software to various parallel systems including Linux Clusters, SGI Altix systems, and Apple G5 XServe systems. We will also describe how the software has been applied in modeling of post-seismic deformation studies of the Landers and Northridge earthquake events.

  8. Active Heat Rejection System on Mars Exploration Rover - Design Changes from Mars Pathfinder

    NASA Astrophysics Data System (ADS)

    Ganapathi, Gani B.; Birur, Gajanana C.; Tsuyuki, Glenn T.; McGrath, Paul L.; Patzold, Jack D.

    2003-01-01

    The active Heat Rejection System designed for Mars Pathfinder was modified for the Mars Exploration Rover (Mars '03) mission and will be used to remove excess heat from the Rover electronics during the cruise part of the mission. The Integrated Pump Assembly design from MPF remained essentially intact; changes were primarily made to reduce weight. However, the cooling loop was significantly redesigned to service totally different requirements for the MER rovers. In addition, the vent design was readdressed to alleviate potentially excessive nutation as was induced on the MPF spacecraft in the process of dumping the CFC-11 overboard prior to Entry/Descent/Landing. The current vent design was based on a better understanding of the flow characteristics during the blowdown process. This paper addresses some of the key design changes. This paper also addresses lessons learned from the performance testing, and potential changes to improve the HRS performance (e.g. temperature oscillations).

  9. Performance-based landfill design: development of a design component selection matrix using GIS and system simulation models

    NASA Astrophysics Data System (ADS)

    Tarhan, Başak; Ünlü, Kahraman

    2005-11-01

    Designing environmentally safe and economically feasible landfills can be a challenging task due to complex interactions that need to be taken into account between landfill size, waste and site characteristics. The main focus of this study is, by interfacing the geographic information systems (GIS) with system simulation models (SSM), to develop a methodology and a landfill design component selection matrix that can enable the determination of landfill design components providing the desired performance with minimal design details. In this paper, the conceptual framework and applications of the developed methodology demonstrating the selection of landfill design components that are suitable for the existing site conditions are presented. The conceptual model defines design variables, performance criteria and design components of a landfill. GIS and SSM are used to handle the site-specific data and to evaluate the landfill performance, respectively. Results indicate that the landfills having the same design characteristics show different performance under different site conditions; therefore, a landfill design that is technically and economically feasible should be selected on the basis of performance.

  10. 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.

  11. 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

  12. Semi-active controller design for vibration suppression and energy harvesting via LMI approach

    NASA Astrophysics Data System (ADS)

    Liu, Yilun; Lin, Chi-Chang; Zuo, Lei

    2014-04-01

    The vibration control plays an important role in energy harvesting systems. Compared to the active control, semi-active control is a more preferred alternative for practical use. Many different semi-active control strategies have been developed, among which LQ-clip, Skyhook and model predictive control are the most popular strategies in literatures. In this paper, a different control strategy that designs semi-active controller via LMI approach is proposed. Different from clipping the control input after controller construction like most existing control methods, the proposed method fulfills the semi-active control input feasibility constraints before the controller construction. The methodology is developed through LMI approach which leads to a stabilizing linear controller to ensure semi-active constraint and the pre-designed performance. An illustrative example, vibration control system of a tall building, is presented to show the efficiency of the method and validate the new approach.

  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. 22 CFR 96.6 - Performance criteria for designation as an accrediting entity.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Performance criteria for designation as an..., Designation, and Duties of Accrediting Entities § 96.6 Performance criteria for designation as an accrediting...: (a) That it has a governing structure, the human and financial resources, and systems of...

  15. 22 CFR 96.6 - Performance criteria for designation as an accrediting entity.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Performance criteria for designation as an..., Designation, and Duties of Accrediting Entities § 96.6 Performance criteria for designation as an accrediting...: (a) That it has a governing structure, the human and financial resources, and systems of...

  16. 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…

  17. 76 FR 49797 - Designation of ONDCP SES Performance Review Board Members

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-11

    ... CONTROL POLICY Designation of ONDCP SES Performance Review Board Members AGENCY: Office of National Drug Control Policy. ACTION: Notice of Designation of ONDCP SES Performance Review Board. Headings: Designation... Office of National Drug Control Policy has appointed Patrick M. Ward, Robert Denniston, Michele Marx,...

  18. 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).

  19. 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…

  20. 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…

  1. 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.

  2. Circuit Design: An Inquiry Lab Activity at Maui Community College

    NASA Astrophysics Data System (ADS)

    Morzinski, K.; Azucena, O.; Downs, C.; Favaloro, T.; Park, J.; U, Vivian

    2010-12-01

    We present an inquiry lab activity on Circuit Design that was conducted in Fall 2009 with first-year community college students majoring in Electrical Engineering Technology. This inquiry emphasized the use of engineering process skills, including circuit assembly and problem solving, while learning technical content. Content goals of the inquiry emphasized understanding voltage dividers (Kirchoff's voltage law) and analysis and optimization of resistive networks (Thévenin equivalence). We assumed prior exposure to series and parallel circuits and Ohm's law (the relationship between voltage, current, and resistance) and designed the inquiry to develop these skills. The inquiry utilized selection of engineering challenges on a specific circuit (the Wheatstone Bridge) to realize these learning goals. Students generated questions and observations during the starters, which were categorized into four engineering challenges or design goals. The students formed teams and chose one challenge to focus on during the inquiry. We created a rubric for summative assessment which helped to clarify and solidify project goals while designing the inquiry and aided in formative assessment during the activity. After describing implementation, we compare and contrast engineering-oriented inquiry design as opposed to activities geared toward science learning.

  3. 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.

  4. Adult Learning Principles in Designing Learning Activities for Teacher Development

    ERIC Educational Resources Information Center

    Gravani, Maria N.

    2012-01-01

    The research reported in this paper is an investigation of the application of adult learning principles in designing learning activities for teachers' life-long development. The exploration is illustrated by qualitative data from a case study of adult educators' and adult learners' insights and experiences of a teacher development course organised…

  5. Programming biological operating systems: genome design, assembly and activation.

    PubMed

    Gibson, Daniel G

    2014-05-01

    The DNA technologies developed over the past 20 years for reading and writing the genetic code converged when the first synthetic cell was created 4 years ago. An outcome of this work has been an extraordinary set of tools for synthesizing, assembling, engineering and transplanting whole bacterial genomes. Technical progress, options and applications for bacterial genome design, assembly and activation are discussed.

  6. 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…

  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. Feed-pump hydraulic performance and design improvement. Final report

    SciTech Connect

    Dunfee, J.D.; Anwar, I.M.; Rusak, V.; Silvaggio, J.A. Jr.; Spring, H.

    1982-03-01

    As a result of surveys of the industry and the literature (1960 to 1980), which are described in detail, a proposed research plan is presented that is designed to improve the reliability of boiler feed pumps, which are a key factor in power plant availability. The proposed research tasks can be divided into three major categories: studies of flow phenomena in the pump, improvement of mechanical components supporting and sealing the rotor, and utility aids designed to offer immediate help to the utilities in areas of pump specification, procurement, maintenance, and reliability. A method is presented of estimating the anticipated payback versus estimated research costs.

  9. 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.…

  10. 14 CFR 91.705 - Operations within airspace designated as Minimum Navigation Performance Specification Airspace.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 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...

  11. 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

  12. Valley Fill Design and Construction Alternatives to Improve Ecological Performance

    EPA Pesticide Factsheets

    This presentation discusses; current challenges, comprehensive approaches, BMPs, the Middlefork Development, the Guy Cove project, and a path forward when looking at construction alternatives to improve the ecological performance of valley fills.

  13. Performance Study and Dynamic Optimization Design for Thread Pool Systems

    SciTech Connect

    Xu, Dongping

    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.

  14. 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.

  15. 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…

  16. 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…

  17. 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…

  18. Neutron beam design, development, and performance for neutron capture therapy

    SciTech Connect

    Harling, O.K.; Bernard, J.A. ); Zamenhof, R.G. )

    1990-01-01

    The report presents topics presented at a workshop on neutron beams and neutron capture therapy. Topics include: neutron beam design; reactor-based neutron beams; accelerator-based neutron beams; and dosimetry and treatment planning. Individual projects are processed separately for the databases. (CBS)

  19. Core design and performance of small inherently safe LMRs

    SciTech Connect

    Orechwa, Y.; Khalil, H.; Turski, R.B.; Fujita, E.K.

    1986-01-01

    Oxide and metal-fueled core designs at the 900 MWt level and constrained by a requirement for interchangeability are described. The physics parameters of the two cores studied here indicate that metal-fueled cores display attractive economic and safety features and are more flexible than are oxide cores in adapting to currently-changing deployment scenarios.

  20. 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).

  1. Design and performance of the KSC biomass production chamber

    SciTech Connect

    Prince, R.P.; Knott, W.M.; Sager, J.C.

    1987-01-01

    An atmospherically sealed chamber has been constructed for the purpose of studying gas, liquid, and microbial contaminants produced by growing food crops. This chamber is designed to provide suitable biomass for evaluation of quality, yield, volume, and energy for different environments and nutrient delivery systems.

  2. 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).

  3. 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.

  4. 24 CFR 902.11 - PHAS performance designation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... financial condition, physical condition, and management operations indicators and at least 50 percent of the... or more of the physical condition, financial condition, or management operations indicators. The PHA... designation is based on the overall PHAS score and the four indicator scores, as set forth below. (a)...

  5. 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.

  6. Prism sodium-cooled reactor design and performance

    SciTech Connect

    Kwant, W.; Magee, P.M.; Patel, M.R. )

    1989-01-01

    The Power Reactor Inherently Safe Module (PRISM) program is being conducted at General Electric (GE) under U.S. Department of Energy sponsorship to develop a conceptual design for an advanced sodium-cooled liquid-metal reactor plant. The PRISM design emphasizes inherent safety, modular construction, and factory fabrication. A PRISM power plant includes a number of reactor modules, which will be fabricated in a factory and shipped by whatever combination of barge, rail, and road transport that is most economical for a particular site. The target commercial PRISM plant utilizes nine reactor modules arranged in three identical 465-MW(electric) power blocks for an overall plant net electrical rating of 1395 MW(electric). Each power block has three identical reactor modules, each with its own steam generator, that jointly supply saturated steam to a single turbine generator. The PRISM's features of fewer and simpler safety systems, seismic isolation, passive decay heat removal, inherent reactivity control, and generous margins from structural and fuel damage limits during potential accident situations will result in significant gains in public safety and protection of the owner's investment. The use of standardized modular construction and extensive factory fabrication is resulting in a plant design that is economically competitive against projected coal plants and other nuclear design approaches.

  7. A Design and Development Model for Building Electronic Performance Support Systems.

    ERIC Educational Resources Information Center

    Cagiltay, Kursat

    This proposed study is to investigate the design and development process of electronic performance support systems (EPSSs). The primary purpose of this study is to help the EPSS designers by proposing a more effective and productive EPSS design and developmental model. By analyzing EPSS products and observing EPSS design projects, the research…

  8. 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.

  9. 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

  10. 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.

  11. Design, synthesis and insecticidal activity of novel phenylurea derivatives.

    PubMed

    Sun, Jialong; Zhou, Yuanming

    2015-03-19

    A series of novel phenylurea derivatives were designed and synthesized according to the method of active groups linkage and the principle of aromatic groups bioisosterism in this study. The structures of the novel phenylurea derivatives were confirmed based on ESI-MS, IR and 1H-NMR spectral data. All of the compounds were evaluated for the insecticidal activity against the third instars larvae of Spodoptera exigua Hiibner, Plutella xyllostella Linnaeus, Helicoverpa armigera Hubner and Pieris rapae Linne respectively, at the concentration of 10 mg/L. The results showed that all of the derivatives displayed strong insecticidal activity. Most of the compounds presented higher insecticidal activity against S. exigua than the reference compounds tebufenozide, chlorbenzuron and metaflumizone. Among the synthesized compounds, 3b, 3d, 3f, 4b and 4g displayed broad spectrum insecticidal activity.

  12. Quantifying the Performance of Individual Players in a Team Activity

    PubMed Central

    Duch, Jordi; Waitzman, Joshua S.; Amaral, Luís A. Nunes

    2010-01-01

    Background Teamwork is a fundamental aspect of many human activities, from business to art and from sports to science. Recent research suggest that team work is of crucial importance to cutting-edge scientific research, but little is known about how teamwork leads to greater creativity. Indeed, for many team activities, it is not even clear how to assign credit to individual team members. Remarkably, at least in the context of sports, there is usually a broad consensus on who are the top performers and on what qualifies as an outstanding performance. Methodology/Principal Findings In order to determine how individual features can be quantified, and as a test bed for other team-based human activities, we analyze the performance of players in the European Cup 2008 soccer tournament. We develop a network approach that provides a powerful quantification of the contributions of individual players and of overall team performance. Conclusions/Significance We hypothesize that generalizations of our approach could be useful in other contexts where quantification of the contributions of individual team members is important. PMID:20585387

  13. Fundamental Investigations and Rational Design of Durable High-Performance SOFC Cathodes

    SciTech Connect

    Chen, Yu; Ding, Dong; Wei, Tao; Liu, Meilin

    2016-03-31

    The main objective of this project is to unravel the degradation mechanism of LSCF cathodes under realistic operating conditions with different types of contaminants, aiming towards the rational design of cathodes with high-performance and enhanced durability by combining a porous backbone (such as LSCF) with a thin catalyst coating. The mechanistic understanding will help us to optimize the composition and morphology of the catalyst layer and microstructure of the LSCF backbone for better performance and durability. More specifically, the technical objectives include: (1) to unravel the degradation mechanism of LSCF cathodes under realistic operating conditions with different types of contaminants using in situ and ex situ measurements performed on specially-designed cathodes; (2) to examine the microstructural and compositional evolution of LSCF cathodes as well as the cathode/electrolyte interfaces under realistic operating conditions; (3) to correlate the fuel cell performance instability and degradation with the microstructural and morphological evolution and surface chemistry change of the cathode under realistic operating conditions; (4) to explore new catalyst materials and electrode structures to enhance the stability of the LSCF cathode under realistic operating conditions; and (5) to validate the long term stability of the modified LSCF cathode in commercially available cells under realistic operating conditions. We have systematically evaluated LSCF cathodes in symmetrical cells and anode supported cells under realistic conditions with different types of contaminants such as humidity, CO2, and Cr. Electrochemical models for the design of test cells and understanding of mechanisms have been developed for the exploration of fundamental properties of electrode materials. It is demonstrated that the activity and stability of LSCF cathodes can be degraded by the introduction of contaminants. The microstructural and compositional evolution of LSCF

  14. 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.

  15. 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.

  16. 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.

  17. Laboratory Investigations of Biomedical Factors Influencing Laser Designator Operator Performance

    DTIC Science & Technology

    1980-06-01

    which included the Armed Forces Visual Acuity Test , Farnsworth Munsell 100- hue Color Vision Test , a dark adaptation test , undilated funduscopic...examination, and a visual history. The color vision, acuity, and funduscopic examina- tion were repeated after the experimental phase of the project. No test ...mixed designs (6). The specific post hoc com- parisons of significant findings were made using Newman-Keuls Tests (7). The 0.05 level was used for

  18. Human Performance Data Needed for Training Device Design Decisions.

    DTIC Science & Technology

    1987-03-01

    know more about night vision and the effect of Training Device (TD) layout on visual perception. Next to vision , the most frequently Queried domain in...general 14 alphanumeric 5 symbols 18 dynamics 10 organization 6 anomalous effects 14 color 5 Night Vision 6 Vision and TD Layout 12 Visual vs. Vestibular...device designers, helping them to find the topic of greatest relevance (e.g., CRT alphanumerics, night vision , motion cues). Such a supplement might

  19. Kepler Mission Design, Realized Photometric Performance, and Early Science

    DTIC Science & Technology

    2010-04-20

    designed with the explicit capability to detect Earth- size planets in the habitable zone of solar-like stars using the transit photometry method...that can be used to distinguish dwarf stars from red giants. Key words: instrumentation: photometers – planetary systems – space vehicles: instruments...characteristics. The method of choice is transit photometry (Pont et al. 2009), which provides the orbital period and size of the planet relative to its

  20. Design and performance of a dynaniic gas flux chamber.

    PubMed

    Reichman, Rivka; Rolston, Dennis E

    2002-01-01

    Chambers are commonly used to measure the emission of many trace gases and chemicals from soil. An aerodynamic (flow through) chamber was designed and fabricated to accurately measure the surface flux of trace gases. Flow through the chamber was controlled with a small vacuum at the outlet. Due to the design using fans, a partition plate, and aerodynamic ends, air is forced to sweep parallel and uniform over the entire soil surface. A fraction of the air flowing inside the chamber is sampled in the outlet. The air velocity inside the chamber is controlled by fan speed and outlet suction flow rate. The chamber design resulted in a uniform distribution of air velocity at the soil surface. Steady state flux was attained within 5 min when the outlet air suction rate was 20 L/min or higher. For expected flux rates, the presence of the chamber did not affect the measured fluxes at outlet suction rates of around 20 L/min, except that the chamber caused some cooling of the surface in field experiments. Sensitive measurements of the pressure deficit across the soil layer in conjunction with measured fluxes in the source box and chamber outlet show that the outflow rate must be controlled carefully to minimize errors in the flux measurements. Both over- and underestimation of the fluxes are possible if the outlet flow rate is not controlled carefully. For this design, the chamber accurately measured steady flux at outlet air suction rates of approximately 20 L/min when the pressure deficit within the chamber with respect to the ambient atmosphere ranged between 0.46 and 0.79 Pa.

  1. 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.

  2. Preliminary optical design of an Active Optics test bench for space applications.

    NASA Astrophysics Data System (ADS)

    Calcines, A.; Bitenc, U.; Rolt, S.; Reeves, S.; Doelman, N.; Human, J.; Morris, T.; Myers, R.; Talbot, G.

    2017-03-01

    This communication presents a preliminary optical design for a test bench conceived within the European Space Agency's TRP project (Active Optics Correction Chain (AOCC) for large monolithic mirrors) with the goal of designing and developing an Active Optics system able to correct in space on telescopes apertures larger than 3 meters. The test bench design uses two deformable mirrors of 37.5 mm and 116 mm, the smallest mirror to generate aberrations and the largest one to correct them. The system is configured as a multi-functional test bench capable of verifying the performance of a Shack-Hartmann wavefront sensor as well as of a Phase Diversity based wavefront sensor. A third optical path leads to a high-order Shack-Hartmann wavefront sensor to monitor the entire system performance.

  3. 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.…

  4. Design and control of an active 1-DoF mechanism for knee rehabilitation.

    PubMed

    Naghavi, Nader; Mahjoob, Mohammad J

    2016-10-01

    A 1-DoF robot is designed and fabricated to be used for knee rehabilitation training. The mechanism (robot) is designed to perform specific set of exercises while the patient is sitting on a chair. The therapy process for patients has different stages; each stage consists of specific exercises to recover the knee to its condition before injury. The maximum torque of healthy joint during the extension/flexion exercise is evaluated by simulation and suitable actuator is selected based on the results. A prototype is then fabricated as a platform to evaluate the design and control concepts. The experiment procedure consisting of three stages of therapy indicates good tracking performance and safe operation of the system. Implication for Rehabilitation A 1-DoF mechanism for knee rehabilitation has been designed to perform three stages of therapy: passive, active assist and active resist. The assistive and resistive torque, during active assist and active resist stages, can be set according to the progress in therapy. The results of this study suggest the system has the potential to result in various benefits including reduction of physical workload of physiotherapists and improved repeatability.

  5. 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.

  6. 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

  7. 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.

  8. Optimal Designs for Performance Assessments: The Subject Factor.

    ERIC Educational Resources Information Center

    Parkes, Jay

    Much speculation abounds concerning how expensive performance assessments are or are going to be. Recent projections indicate that, in order to achieve an acceptably high generalizability coefficient, many additional tasks may need to be added, which will enlarge costs. Such projections are, to some degree, correct, and to some degree simplistic.…

  9. 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…

  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. 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.

  12. 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 ...

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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…

  20. 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.

  1. Design and performances of the Scrap Neutron Multiplicity Counter

    NASA Astrophysics Data System (ADS)

    Marin Ferrer, Montserrat; Peerani, Paolo; Looman, Marc R.; Dechamp, Luc

    2007-05-01

    JRC has developed the Scrap Neutron Multiplicity Counter (SNMC): an advanced neutron multiplicity counter for the verification of inhomogeneous Pu samples, such as scrap material in MOX fuel fabrication plants. The innovative features of this counter with respect to existing ones rely on two aspects: (i) an optimised design based on Monte Carlo calculations in order to select the most appropriate materials, geometry and detector disposition for maximum efficiency and (ii) novel electronics based on digital signal processing (DSP) reducing the system dead time. The paper recalls the design process, the electronics, the construction and assembly of the counter. Then the results of the first experimental tests will be reported. We will show the characterization of the main physical parameters of the counter, the calibration and the verification of a wide variety of plutonium bearing samples available in the PERLA laboratory at JRC Ispra. This will include pure homogeneous samples (Pu dioxide powders, metal Pu, MOX powders and pellets) and some tests on heterogeneous samples representative of scrap material.

  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. 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…

  4. 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.

  5. Design Activity in the Software Cost Reduction Project.

    DTIC Science & Technology

    1986-08-18

    PM Physical Model S G System Generation SS Shared Services SU System Utilities . NOV M N 1600SEP A 0 JUL TOTAL 14000 MAAR cc 100 FEB :IESGN 0o 10000...iy---- .... ;’ TESTING Jan 78 Jan 79 Jan 80 Jan 81 Jan 82 Jan 83 Jan 84 Jan 85 M3ITH Fig. 7 - Shared services activities A F 0 U E C 1600 G B T...DISCUSSING 200M Jan 78 Jan 79 Jan 80 Jan 81 Jan 82 Jan 83 Jan 84 Jan 85 Fig 13 - Shared services design activities 5.~ S% 12 ......,ooU7 . . NRL REPORT 8974 A

  6. 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.

  7. A designed supramolecular protein assembly with in vivo enzymatic activity.

    PubMed

    Song, Woon Ju; Tezcan, F Akif

    2014-12-19

    The generation of new enzymatic activities has mainly relied on repurposing the interiors of preexisting protein folds because of the challenge in designing functional, three-dimensional protein structures from first principles. Here we report an artificial metallo-β-lactamase, constructed via the self-assembly of a structurally and functionally unrelated, monomeric redox protein into a tetrameric assembly that possesses catalytic zinc sites in its interfaces. The designed metallo-β-lactamase is functional in the Escherichia coli periplasm and enables the bacteria to survive treatment with ampicillin. In vivo screening of libraries has yielded a variant that displays a catalytic proficiency [(k(cat)/K(m))/k(uncat)] for ampicillin hydrolysis of 2.3 × 10(6) and features the emergence of a highly mobile loop near the active site, a key component of natural β-lactamases to enable substrate interactions.

  8. Impact of study design on development and evaluation of an activity-type classifier.

    PubMed

    van Hees, Vincent T; Golubic, Rajna; Ekelund, Ulf; Brage, Søren

    2013-04-01

    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.

  9. 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.

  10. 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.

  11. Designing minimal space telerobotics systems for maximum performance

    NASA Technical Reports Server (NTRS)

    Backes, Paul G.; Long, Mark K.; Steele, Robert D.

    1992-01-01

    The design of the remote site of a local-remote telerobot control system is described which addresses the constraints of limited computational power available at the remote site control system while providing a large range of control capabilities. The Modular Telerobot Task Execution System (MOTES) provides supervised autonomous control, shared control and teleoperation for a redundant manipulator. The system is capable of nominal task execution as well as monitoring and reflex motion. The MOTES system is minimized while providing a large capability by limiting its functionality to only that which is necessary at the remote site and by utilizing a unified multi-sensor based impedance control scheme. A command interpreter similar to one used on robotic spacecraft is used to interpret commands received from the local site. The system is written in Ada and runs in a VME environment on 68020 processors and initially controls a Robotics Research K1207 7 degree of freedom manipulator.

  12. High Performance Concentrating Photovoltaic Module Designs Employing Reflective Lens Optics

    NASA Astrophysics Data System (ADS)

    Vasylyev, Sergey V.; Vasylyev, Viktor P.

    2011-12-01

    The present study is aimed at advancing the optical component as well as optimizing the design of concentrating photovoltaic (CPV) modules in order to increase the conversion efficiency and improve the utility of CPV while obtaining the prescribed concentration ratio. In this work, we turn to non-traditional concentrating optics, namely Reflective Lenses™ (RL), first introduced in early 2000s. The optical configuration of RLs is unique since it combines the very low F/D number (hence resulting in a very low profile of the unit) of mirrors with a rear-focus of lenses and uses only a single-stage reflection. A liner-focus version of RLs, the Slat-Array Concentrator (SAC), is a capable alternative to the parabolic troughs for mid-concentration CPV. A point-focus version called the Ring-Array Concentrator (RAC) is deemed suitable for high concentration photovoltaics.

  13. Design and performance of a piezoelectric actuated precise rotary positioner

    NASA Astrophysics Data System (ADS)

    Wang, Y. C.; Chang, S. H.

    2006-10-01

    Industries including semiconductor, biotechnology, and nanotechnology are seeking compact and reliable nanometer resolution positioning techniques. To address this demand, this article presents a friction-drive rotary stage driven by a piezoelectric transducer (PZT) actuator. This stage includes a multilayer PZT actuator, the Scott-Russell mechanism, an actuation stage, a preload spring, and an output shaft. Its rotary positioning is accomplished by the stick-slip effect between the wire electrodischarge-machining rotary stage and the output shaft. Finite element analysis and Taguchi optimization method were extensively conducted to analyze the displacement, stress, and vibration behavior for optimum design. As shown by the experimental results, the stage achieved a resolution of 0.13μrad and a speed of 0.15°/h by tuning of the preload spring.

  14. Effects of pen design on drawing and writing performance.

    PubMed

    Goonetilleke, Ravindra S; Hoffmann, Errol R; Luximon, Ameersing

    2009-03-01

    Two experiments are reported with the aim of determining the effect of pen shape and size on two different types of task: drawing and writing. Experiment 1 attempted to determine the optimum shape and size of shank for ball-point pens used to perform an accurate drawing task. Twenty-seven participants used a total of nine different pens. Drawing performance was measured by having the subjects follow mazes of different size. The dependent variables were drawing movement time and drawing accuracy. The results indicate that the pen with an equivalent diameter of 8mm had the best accuracy during drawing, even though it had the lowest speed. The results confirm the applicability and validity of the Drury tracking model for such a task. Even though users tended to prefer larger pens, their accuracy with such pens tended to be low. In a second experiment, subjects performed a writing task (with no accuracy constraints) and rated their preference for types of pen. An attempt was made to determine the preferred dimensions of ball-point pens for writing in Chinese and English. A total of 36 'bare-bodied' pens and 20 Chinese subjects were used to evaluate the effects of shape, size and weight on time to write a sentence. The Writing Ability, Comfort and an Overall Rating were given by the subjects. The results indicate that the Chinese subjects preferred a circular shaped pen for writing in both languages. A factor analysis showed that speed, comfort and writing ability are independent parameters in pen evaluations.

  15. Design and performance of differential pumping system of coating unit

    NASA Astrophysics Data System (ADS)

    Karmakar, P.; Maiti, N.; Bapat, A. V.

    2008-05-01

    A box type coating unit has been developed in view of dual purpose of optical and reactive coating. The system is divided in two parts namely, substrate chamber (800mm × 800 mm × 100 mm) and gun chamber (800mm × 800 mm × 100 mm). Coating material is evaporated in the substrate chamber by traverse (270°) electron beams. Reactive gas is injected in the substrate chamber by up-stream pressure controller to reach set pressures in the range of 1×10-3 mbar to 1×10-4 mbar for gas flow rate in the range of 0-30 sccm. Traverse EB guns (10 kV, 15 kW, 2 No) are mounted inside gun chamber. The gun chamber vacuum should be better than 1×10-5 mbar for the operation of EB guns. Both these chambers are connected by the apertures provided on the intermediate bifurcation plate for the passage of electron beams. Through the apertures the reactive gas leaks from the substrate chamber to the gun chamber due to differential pressure. The differential pumping system consists of individual pumping modules for the substrate chamber and the gun chamber. The paper focuses upon the design of differential pumping system in view of determination of steady state differential pressures for different flow rates of reactive gas. It has been noticed that on introduction of reactive gas in the substrate chamber, the pressures in the substrate chamber and the gun chamber oscillates before converging to steady state values. Theoretically calculated values have been compared with the experimental values as design validation.

  16. 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.

  17. Manholes within MSW landfills - design, construction and performance

    SciTech Connect

    Paruvakat, N.; Marman, S.; Thompson, S.

    1995-12-31

    Two interior manholes (located within the waste) were required for an efficient, workable improvement and expansion of a solid waste landfill in southeastern Wisconsin. Due to the less than satisfactory performance of some interior manholes in the past, the project received close scrutiny and required attention to be paid to every minute detail. Geotechnical and structural analyses conducted to evaluate the loads on, and settlement of, the manhole are described. Since the improvements at the site included leachate management from the existing and future waste fill areas, plumbing considerations were very important. These are detailed. Construction and monitoring of settlement of the manholes are discussed.

  18. 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.

  19. Comparative Effect of Orthosis Design on Functional Performance

    DTIC Science & Technology

    2012-03-21

    S , Bell KJ, Davis RB 3rd, DeLuca PA. An evaluation of the posterior leaf spring orthosis using joint kinematics and kinetics. J Pediatr Orthop...GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) Patzkowski J. C., Blanck R. V., Owens J. G., Wilken J. M., Kirk K. L., Wenke J. C., Hsu J. R...5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) United States Army Institute of

  20. IRSPEC: Design, performance and first scientific results (Invited)

    NASA Astrophysics Data System (ADS)

    Moorwood, A. F. M.

    IRSPEC is a cooled grating spectrometer currently equipped with a monolithic, linear, array of InSb diodes coupled to a Reticon multiplexer. The array is sensitive between 1 μm and 5 μm, has a pixel size of 200 μm corresponding to a 6 arcsec slit on the ESO 3.6 m telescope and yields resolving powers between 1000 and 2500 depending on wavelength and grating order. The overall performance is illustrated by a variety of astronomical spectra and a brief report on recent scientific results from observations of supernova remnants and galaxy nuclei.

  1. 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.

  2. SKA weak lensing- II. Simulated performance and survey design considerations

    NASA Astrophysics Data System (ADS)

    Bonaldi, Anna; Harrison, Ian; Camera, Stefano; Brown, Michael L.

    2016-12-01

    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 optimize a 2-yr 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 5000 deg2 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.

  3. 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

  4. High-Performance Design Patterns for Modern Fortran

    DOE PAGES

    Haveraaen, Magne; Morris, Karla; Rouson, Damian; ...

    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

  5. 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.

  6. A novel design of semi-active hydraulic mount with wide-band tunable notch frequency

    NASA Astrophysics Data System (ADS)

    Wang, Min; Yao, Guo-feng; Zhao, Jing-zhou; Qin, Min

    2014-04-01

    Hydraulic engine mount is advanced vibration isolator with superior performance to reduce vibration transferred from engine to chassis. As the stiffness at notch frequency is small, some semi-active or active hydraulic mounts tune some parameters to let notch frequency coincide with exciting frequency for better vibration isolation performance. It is discovered the current semi-active mounts can tune the notch frequency in narrow frequency band when only one parameter is tuned. A novel semi-active hydraulic engine mount design which introduces screw thread is proposed and researched in the paper. This hydraulic mount can control both cross section area and the length of inertia track and the theoretical tunable notch frequency band is [0, ∞). Theoretical work is carried out to uncover the capability for the proposed design to tune notch frequency. Simulation work is performed to understand its high vibration isolation performance. For the purpose of energy conservation, the friction self-locking is introduced. This denotes once the mount is tuned at optimal condition, the energy can be cut off and the optimal condition will never change. We also determine the best time to tune the parameters of the proposed mount in order to decrease the acting force. The proposed semi-active mount has capability to obtain wide band tunable notch frequency and has merit of energy conservation.

  7. Background activities, induction, and behavioral allocation in operant performance.

    PubMed

    Baum, William M; Davison, Michael

    2014-09-01

    In experiments on operant behavior, other activities, called "background" activities, compete with the operant activities. Herrnstein's (1970) formulation of the matching law included background reinforcers in the form of a parameter rO, but remained vague about the activities (BO) that produce rO. To gain more understanding, we analyzed data from three studies of performance with pairs of variable-interval schedules that changed frequently in the relative rate at which they produced food: Baum and Davison (2014), Belke and Heyman (1994), and Soto, McDowell, and Dallery (2005). Results sometimes deviated from the matching law, suggesting variation in rO. When rO was calculated from the matching equation, two results emerged: (a) rO is directly proportional to BO, as in a ratio schedule; and (b) rO and BO depend on the food rate, which is to say that BO consists of activities induced by food, as a phylogenetically important event. Other activities unrelated to food (BN ) correspond to Herrnstein's original conception of rO and may be included in the matching equation. A model based on Baum's (Baum, 2012) concepts of allocation, induction, and contingency explained the deviations from the matching law. In the model, operant activity B, BO, and BN competed unequally in the time allocation: B and BO both replaced BN , BO replaced lever pressing (Soto et al.), and key pecking replaced BO (Baum & Davison). Although the dependence of rO and BO on food rate changes Herrnstein's (1970) formulation, the model preserved the generalized matching law for operant activities by incorporating power-function induction.

  8. Aspects of achievable performance for quarter-car active suspensions

    NASA Astrophysics Data System (ADS)

    Türkay, Semiha; Akçay, Hüseyin

    2008-03-01

    In this paper, constraints on the transfer functions from the road disturbance to the vertical acceleration, the suspension travel, and the tire deflection are derived for a quarter-car active suspension system using the vertical acceleration and/or the suspension travel measurements for feedback. The derived constraints complement the similar constraints in the literature. By using the factorization approach to feedback stability, it is shown that tire damping couples the motions of the sprung and unsprung masses; and eliminates a constraint at the wheel-hop frequency. The influence of tire damping on the design of an active suspension system for a quarter-car model by a mixture of the LQG methodology and the interpolation approach is also illustrated.

  9. Decoupling interrelated parameters for designing high performance thermoelectric materials.

    PubMed

    Xiao, Chong; Li, Zhou; Li, Kun; Huang, Pengcheng; Xie, Yi

    2014-04-15

    The world's supply of fossil fuels is quickly being exhausted, and the impact of their overuse is contributing to both climate change and global political unrest. In order to help solve these escalating problems, scientists must find a way to either replace combustion engines or reduce their use. Thermoelectric materials have attracted widespread research interest because of their potential applications as clean and renewable energy sources. They are reliable, lightweight, robust, and environmentally friendly and can reversibly convert between heat and electricity. However, after decades of development, the energy conversion efficiency of thermoelectric devices has been hovering around 10%. This is far below the theoretical predictions, mainly due to the interdependence and coupling between electrical and thermal parameters, which are strongly interrelated through the electronic structure of the materials. Therefore, any strategy that balances or decouples these parameters, in addition to optimizing the materials' intrinsic electronic structure, should be critical to the development of thermoelectric technology. In this Account, we discuss our recently developed strategies to decouple thermoelectric parameters for the synergistic optimization of electrical and thermal transport. We first highlight the phase transition, which is accompanied by an abrupt change of electrical transport, such as with a metal-insulator and semiconductor-superionic conductor transition. This should be a universal and effective strategy to optimize the thermoelectric performance, which takes advantage of modulated electronic structure and critical scattering across phase transitions to decouple the power factor and thermal conductivity. We propose that solid-solution homojunction nanoplates with disordered lattices are promising thermoelectric materials to meet the "phonon glass electron crystal" approach. The formation of a solid solution, coupled with homojunctions, allows for

  10. Iptycenes in the design of high performance polymers.

    PubMed

    Swager, Timothy M

    2008-09-01

    This Account details the use of building blocks known as iptycene units, which are particularly useful in the design of advanced materials because of their three-dimensional, noncompliant structures. Iptycenes are built upon [2,2,2]-ring systems in which the bridges are aromatic rings, and the simplest member of this class of compounds is triptycene. Iptycenes can provide steric blocking, which can prevent strong interactions between polymeric chromophores that have a strong tendency to form nonemissive exciplex complexes. Iptycene-containing conjugated polymers are exceptionally stable and display solution-like emissive spectra and quantum yields in the solid state. This application of iptycenes has enabled new vapor detection methods for ultratrace detection of high explosives that are now used by the U.S. military. The three-dimensional shape of iptycenes creates interstitial space (free volume) around the molecules. This space can confer size selectivity in sensory responses and also promotes alignment in oriented polymers and liquid crystals. Specifically, the iptycene-containing polymers and molecules align in the anisotropic host material in a way that minimizes the free volume. This effect can be used to align molecules contrary to what would be predicted by conventional models on the basis of aspect ratios. In one demonstration, we show that an iptycene polymer aligns orthogonally to the host polymer when stretched, and these structures approximate molecular versions of woven cloth. In liquid crystal solutions, the conjugated iptycene-containing polymers exhibit greater electronic delocalization, and the transport of excited states along the polymer backbone is observed. Structures that preserve high degrees of internal free volume can also be designed to create low dielectric constant insulators. These materials have high temperature stability (>500 degrees C) and hardness that make them potential interlayer dielectric materials for integrated circuits

  11. Off-Design Performance Prediction of Gas Turbines without the use of Compressor or Turbine Characteristics

    NASA Astrophysics Data System (ADS)

    Suraweera, Janitha Kanishka

    A new method of predicting gas turbine off-design performance is presented. This method, referred to as the core control method, is based on the idea that performance across a gas turbine depends on a single parameter that controls the energy input to the said gas turbine. It is shown that only the design-point performance of a gas turbine is needed to predict its off-design performance, and that neither compressor nor turbine characteristics are required. A thermodynamic model is developed for predicting the off-design performance of a single-spool turbojet and a two-spool gas generator with a free power turbine. This model is further developed to simulate the effects of handling bleed schedules, performance limiters and performance deterioration. The core control method is then used to predict the off-design performance of a Rolls-Royce Viper Mark 521 as a proof-of-concept, after which, the new and deteriorated off-design performance of three Rolls-Royce RB211-24GT gas turbines is predicted. In addition to the discussions on the involved theories and the performance predictions, the process by which the deteriorated RB211-24GT performance data was analyzed, and the sources and propagation of measurement uncertainties are also discussed.

  12. Materials design data for reduced activation martensitic steel type EUROFER

    NASA Astrophysics Data System (ADS)

    Tavassoli, A.-A. F.; Alamo, A.; Bedel, L.; Forest, L.; Gentzbittel, J.-M.; Rensman, J.-W.; Diegele, E.; Lindau, R.; Schirra, M.; Schmitt, R.; Schneider, H. C.; Petersen, C.; Lancha, A.-M.; Fernandez, P.; Filacchioni, G.; Maday, M. F.; Mergia, K.; Boukos, N.; Baluc; Spätig, P.; Alves, E.; Lucon, E.

    2004-08-01

    Materials design limits derived so far from the data generated in Europe for the reduced activation ferritic/martensitic (RAFM) steel type Eurofer are presented. These data address the short-term needs of the ITER Test Blanket Modules and a DEMOnstration fusion reactor. Products tested include plates, bars, tubes, TIG and EB welds, as well as powder consolidated blocks and solid-solid HIP joints. Effects of thermal ageing and low dose neutron irradiation are also included. Results are sorted and screened according to design code requirements before being introduced in reference databases. From the physical properties databases, variations of magnetic properties, modulus of elasticity, density, thermal conductivity, thermal diffusivity, specific heat, mean and instantaneous linear coefficients of thermal expansion versus temperature are derived. From the tensile and creep properties databases design allowable stresses are derived. From the instrumented Charpy impact and fracture toughness databases, ductile to brittle transition temperature, toughness and behavior of materials in different fracture modes are evaluated. From the fatigue database, total strain range versus number of cycles to failure curves are plotted and used to derive fatigue design curves. Cyclic curves are also derived and compared with monotonic hardening curves. Finally, irradiated and aged materials data are compared to ensure that the safety margins incorporated in unirradiated design limits are not exceeded.

  13. The sPHENIX Detector: Design and Performance Requirements

    NASA Astrophysics Data System (ADS)

    Mannel, Eric; Sphenix Collaboration

    2016-09-01

    A new detector, sPHENIX, is being proposed to explore the quark-gluon plasma through measurements of jet properties in heavy ion collisions at the Relativistic Heavy Ion Collider, RHIC, at Brookhaven National Laboratory. The detector is based on the 1.5T super conducting solenoid magnet formerly used for the BaBar experiment and provides charged particle tracking, electromagnetic and hadronic calorimetry with a high speed data acquisition system capable of recording data at rates up to 15 KHz. In this talk we will present the performance requirements of the calorimeters and tracking systems, along with preliminary results from prototype tests at the Fermilab Test Beam Facility and future prospects for sPHENIX.

  14. Cost performance satellite design using queueing theory. [via digital simulation

    NASA Technical Reports Server (NTRS)

    Hein, G. F.

    1975-01-01

    A modified Poisson arrival, infinite server queuing model is used to determine the effects of limiting the number of broadcast channels (C) of a direct broadcast satellite used for public service purposes (remote health care, education, etc.). The model is based on the reproductive property of the Poisson distribution. A difference equation has been developed to describe the change in the Poisson parameter. When all initially delayed arrivals reenter the system a (C plus 1) order polynomial must be solved to determine the effective value of the Poisson parameter. When less than 100% of the arrivals reenter the system the effective value must be determined by solving a transcendental equation. The model was used to determine the minimum number of channels required for a disaster warning satellite without degradation in performance. Results predicted by the queuing model were compared with the results of digital simulation.

  15. Communication in Performance-Based Training and Instruction: From Design to Practice

    ERIC Educational Resources Information Center

    Larbi-Apau, Josephine A.; Moseley, James L.

    2009-01-01

    Communication is inextricably important to instructional design and performance-based training. Promoting effective communication as an integral part of the performance support system improves professional instructional design functions and offers greater avenues for meaningful discourse among end users of the instruction. In this article, we…

  16. 28 CFR 0.31 - Designating officials to perform the functions of the Director.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Designating officials to perform the functions of the Director. 0.31 Section 0.31 Judicial Administration DEPARTMENT OF JUSTICE ORGANIZATION OF THE DEPARTMENT OF JUSTICE Community Relations Service § 0.31 Designating officials to perform...

  17. Space tug point design study. Volume 2: Operations, performance and requirements

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A design study to determine the configuration and characteristics of a space tug was conducted. Among the subjects analyzed in the study are: (1) flight and ground operations, (2) vehicle flight performance and performance enhancement techniques, (3) flight requirements, (4) basic design criteria, and (5) functional and procedural interface requirements between the tug and other systems.

  18. 77 FR 30016 - Clinical Study Design and Performance of Hospital Glucose Sensors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-21

    ... Sensors AGENCY: Food and Drug Administration, HHS. ACTION: Notice of public meeting; request for comments... Study Design and Performance of Hospital Glucose Sensors.'' The purpose of this public meeting is to discuss clinical study design considerations and performance metrics for innovative glucose...

  19. The EXIST Infra-Red Telescope System: Design and Performance

    NASA Technical Reports Server (NTRS)

    Moseley, Samuel H.

    2010-01-01

    The Infra-Red Telescope is a critical element of the EXIST (Energetic X-Ray Imaging Survey Telescope) observatory. It is a passively cooled 1.lm visible/infrared telescope. The primary goal of the IRT is to obtain photometric and spectroscopic measurements of high redshift (>6) gamma ray burst afterglows to study the nature of these enigmatic events and their environments, and to use them as probes of the composition and ionization state of the intergalactic medium of the young universe. The IRT will provide a prompt follow up (within three minutes) of the transient discovered by the EXIST with exceptional NIR sensitivity (AB=24 in 100s) surpassing HST in the infrared due to its passively cooled (- 30 C) mirror. Its optical design and spectral coverage is tailored to the high redshift transient events that require prompt pointing, identification, accurate photometry and both low and high resolution spectroscopy. Here we describe the telescope, its instrument complement, and the cooling systems which provide its remarkable sensitivity

  20. Design and performance of the ALS diagnostic beamline

    SciTech Connect

    Renner, T.; Padmore, H.A.; Keller, R.

    1995-09-01

    Synchrotron light sources have evolved from accelerators which produced this radiation as a by-product to dedicated, third generation storage rings such as the Advanced Light Source (ALS). Optimization of beam line designs to take advantage of these new sources requires information on electron beam parameters and their stability. A real-time, image of the electron beam is useful to accelerator physicists in helping their understanding of beam dynamics, monitoring of accelerator operation, and providing a means of diagnosing problems as they arise. A diagnostic beam line for these purposes has been built at the ALS to image the electron beam by focusing bend magnet radiation. Measurement of beam parameters, electron-bunch time structure and beam dynamics can now be routinely made. The image of the electron beam can be continuously monitored via standard video equipment and the size and location of the beam redundantly measured via a second detection system utilizing a slit scanned in front of a photocathode. Longitudinal electron bunch lengths can be measured with a port providing visible light to an optical platform on which a fast photodiode or a streak camera can be mounted. An additional set of diagnostic tools built into the beam line allows determination of the acceptance of the beam line and the locations of the vertical and horizontal focal planes of the system. The system also provides a discrete method of attenuating the photon flux for equalizing the signal on the video system over the wide range of expected accelerator operating conditions.