Science.gov

Sample records for experimental configuration analysis

  1. Biomechanical behaviour of oesophageal tissues: material and structural configuration, experimental data and constitutive analysis.

    PubMed

    Natali, Arturo N; Carniel, Emanuele L; Gregersen, Hans

    2009-11-01

    The aim of the present work is to propose an approach to the biomechanical analysis of oesophagus by defining an appropriate constitutive model and the associated constitutive parameters. The configuration of the different tissues and layers that compose the oesophagus shows very complicated internal anatomy, geometry and mechanical properties. The coupling of these tissues adds to the complexity. The constitutive models must be capable of interpreting the highly non-linear mechanical response. This is done adopting a specific hyperelastic anisotropic formulation. Experimental data are essential for the investigation of the tissues' biomechanical behaviour and also represent the basis for the definition of constitutive parameters to be adopted within the constitutive formulation developed. This action is provided by using a specific stochastic optimization procedure, addressed to the minimization of a cost function that interprets the discrepancy between experimental data and results from the analytical models developed. Unfortunately, experimental data at disposal do not satisfy all requested information and a particular solution must be provided with regard to definition of the lateral contraction of soft tissues. The anisotropic properties of the tissues are investigated considering the configuration of embedded fibres, according to their mechanical characteristics, quantity and distribution. Collagen and muscular fibres must be considered. The formulation provided on the basis of axiomatic theory of constitutive relationships and the procedure for constitutive parameters identification are described. The evaluation of constitutive parameters requires the analysis of data from experimental tests, that are extracted from the literature. Result validation is performed by comparing the experimental data and model results. In this way a valid basis is provided for the investigation of biomechanical behaviour of oesophagus, looking at deeper information from the

  2. Numerical and experimental analysis of a darrieus-type cross flow water turbine in bare and shrouded configurations

    NASA Astrophysics Data System (ADS)

    Roa, A. M.; Aumelas, V.; Maître, T.; Pellone, C.

    2010-08-01

    The aim of this paper is to present the results of the analysis of a Darrieus-type cross flow water turbine in bare and shrouded configurations. Numerical results are compared to experimental data and differences found in values are also highlighted. The benefit of the introduction of a channelling device, which generates an efficiency increment factor varying from 2 to 5, depending on the configuration, is discussed.

  3. Configuration Analysis Tool

    NASA Technical Reports Server (NTRS)

    Merwarth, P. D.

    1983-01-01

    Configuration Analysis Tool (CAT), is information storage and report generation system for aid of configuration management activities. Configuration management is discipline composed of many techniques selected to track and direct evolution of complex systems. CAT is interactive program that accepts, organizes and stores information pertinent to specific phases of project.

  4. Experimental verification of low sonic boom configuration

    NASA Technical Reports Server (NTRS)

    Ferri, A.; Wang, H. H.; Sorensen, H.

    1972-01-01

    A configuration designed to produce near field signature has been tested at M = 2.71 and the results are analyzed, by taking in account three-dimensional and second order effects. The configuration has an equivalent total area distribution that corresponds to an airplane flying at 60,000 ft. having a weight of 460,000 lbs, and 300 ft. length. A maximum overpressure of 0.95 lb/square foot has been obtained experimentally. The experimental results agree well with the analysis. The investigation indicates that the three-dimensional effects are very important when the measurements in wind tunnels are taken at small distances from the airplane.

  5. Experimental analysis of internal gas flow configurations for a polymer electrolyte membrane fuel cell stack

    NASA Astrophysics Data System (ADS)

    Friedl, A.; Fraser, S. D.; Baumgartner, W. R.; Hacker, V.

    The internal gas distribution system utilised for supplying fresh reactants and removing reaction products from the individual cells of a fuel cell stack can be designed in a parallel, a serial or a mixture of parallel and serial gas flow configuration. In order to investigate the interdependence between the internal stack gas distribution configuration and single cell as well as overall stack performance, a small laboratory-scale fuel cell stack consisting of identical unit cells was subject to operation with different gas distribution configurations and different operating parameters. The current/voltage characteristics measured with the different gas distribution configurations are analysed and compared on unit cell- as well as on stack-level. The results show the significant impact of the internal stack gas distribution system on operation and performance of the individual unit cells and the overall stack.

  6. Experimental and numerical analysis of the wing rock characteristics of a 'wing-body-tail' configuration

    NASA Technical Reports Server (NTRS)

    Suarez, Carlos J.; Smith, Brooke C.; Malcolm, Gerald N.

    1993-01-01

    Free-to-roll wind tunnel tests were conducted and a computer simulation exercise was performed in an effort to investigate in detail the mechanism of wing rock on a configuration that consisted of a highly-slender forebody and a 78 deg swept delta wing. In the wind tunnel test, the roll angle and wing surface pressures were measured during the wing rock motion. A limit cycle oscillation was observed for angles of attack between 22 deg and 30 deg. In general, the wind tunnel test confirmed that the main flow phenomena responsible for the wing-body-tail wing rock are the interactions between the forebody and the wing vortices. The variation of roll acceleration (determined from the second derivative of the roll angle time history) with roll angle clearly showed the energy balance necessary to sustain the limit cycle oscillation. Pressure measurements on the wing revealed the hysteresis of the wing rock process. First, second and nth order models for the aerodynamic damping were developed and examined with a one degree of freedom computer simulation. Very good agreement with the observed behavior from the wind tunnel was obtained.

  7. Operational Dynamic Configuration Analysis

    NASA Technical Reports Server (NTRS)

    Lai, Chok Fung; Zelinski, Shannon

    2010-01-01

    Sectors may combine or split within areas of specialization in response to changing traffic patterns. This method of managing capacity and controller workload could be made more flexible by dynamically modifying sector boundaries. Much work has been done on methods for dynamically creating new sector boundaries [1-5]. Many assessments of dynamic configuration methods assume the current day baseline configuration remains fixed [6-7]. A challenging question is how to select a dynamic configuration baseline to assess potential benefits of proposed dynamic configuration concepts. Bloem used operational sector reconfigurations as a baseline [8]. The main difficulty is that operational reconfiguration data is noisy. Reconfigurations often occur frequently to accommodate staff training or breaks, or to complete a more complicated reconfiguration through a rapid sequence of simpler reconfigurations. Gupta quantified a few aspects of airspace boundary changes from this data [9]. Most of these metrics are unique to sector combining operations and not applicable to more flexible dynamic configuration concepts. To better understand what sort of reconfigurations are acceptable or beneficial, more configuration change metrics should be developed and their distribution in current practice should be computed. This paper proposes a method to select a simple sequence of configurations among operational configurations to serve as a dynamic configuration baseline for future dynamic configuration concept assessments. New configuration change metrics are applied to the operational data to establish current day thresholds for these metrics. These thresholds are then corroborated, refined, or dismissed based on airspace practitioner feedback. The dynamic configuration baseline selection method uses a k-means clustering algorithm to select the sequence of configurations and trigger times from a given day of operational sector combination data. The clustering algorithm selects a simplified

  8. Inferring unstable equilibrium configurations from experimental data

    NASA Astrophysics Data System (ADS)

    Virgin, L. N.; Wiebe, R.; Spottswood, S. M.; Beberniss, T.

    2016-09-01

    This research considers the structural behavior of slender, mechanically buckled beams and panels of the type commonly found in aerospace structures. The specimens were deflected and then clamped in a rigid frame in order to exhibit snap-through. That is, the initial equilibrium and the buckled (snapped-through) equilibrium configurations both co-existed for the given clamped conditions. In order to transit between these two stable equilibrium configurations (for example, under the action of an externally applied load), it is necessary for the structural component to pass through an intermediate unstable equilibrium configuration. A sequence of sudden impacts was imparted to the system, of various strengths and at various locations. The goal of this impact force was to induce relatively intermediate-sized transients that effectively slowed-down in the vicinity of the unstable equilibrium configuration. Thus, monitoring the velocity of the motion, and specifically its slowing down, should give an indication of the presence of an equilibrium configuration, even though it is unstable and not amenable to direct experimental observation. A digital image correlation (DIC) system was used in conjunction with an instrumented impact hammer to track trajectories and statistical methods used to infer the presence of unstable equilibria in both a beam and a panel.

  9. An experimental and theoretical analysis of the aerodynamic characteristics of a biplane-winglet configuration. M.D. Thesis

    NASA Technical Reports Server (NTRS)

    Gall, P. D.

    1984-01-01

    Improving the aerodynamic characteristics of an airplane with respect to maximizing lift and minimizing induced and parasite drag are of primary importance in designing lighter, faster, and more efficient aircraft. Previous research has shown that a properly designed biplane wing system can perform superiorly to an equivalent monoplane system with regard to maximizing the lift-to-drag ratio and efficiency factor. Biplanes offer several potential advantages over equivalent monoplanes, such as a 60-percent reduction in weight, greater structural integrity, and increased roll response. The purpose of this research is to examine, both theoretically and experimentally, the possibility of further improving the aerodynamic characteristics of the biplanes configuration by adding winglets. Theoretical predictions were carried out utilizing vortex-lattice theory, which is a numerical method based on potential flow theory. Experimental data were obtained by testing a model in the Pennsylvania State University's subsonic wind tunnel at a Reynolds number of 510,000. The results showed that the addition of winglets improved the performance of the biplane with respect to increasing the lift-curve slope, increasing the maximum lift coefficient, increasing the efficiency factor, and decreasing the induced drag. A listing of the program is included in the Appendix.

  10. Analysis of Advanced Rotorcraft Configurations

    NASA Technical Reports Server (NTRS)

    Johnson, Wayne

    2000-01-01

    Advanced rotorcraft configurations are being investigated with the objectives of identifying vehicles that are larger, quieter, and faster than current-generation rotorcraft. A large rotorcraft, carrying perhaps 150 passengers, could do much to alleviate airport capacity limitations, and a quiet rotorcraft is essential for community acceptance of the benefits of VTOL operations. A fast, long-range, long-endurance rotorcraft, notably the tilt-rotor configuration, will improve rotorcraft economics through productivity increases. A major part of the investigation of advanced rotorcraft configurations consists of conducting comprehensive analyses of vehicle behavior for the purpose of assessing vehicle potential and feasibility, as well as to establish the analytical models required to support the vehicle development. The analytical work of FY99 included applications to tilt-rotor aircraft. Tilt Rotor Aeroacoustic Model (TRAM) wind tunnel measurements are being compared with calculations performed by using the comprehensive analysis tool (Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics (CAMRAD 11)). The objective is to establish the wing and wake aerodynamic models that are required for tilt-rotor analysis and design. The TRAM test in the German-Dutch Wind Tunnel (DNW) produced extensive measurements. This is the first test to encompass air loads, performance, and structural load measurements on tilt rotors, as well as acoustic and flow visualization data. The correlation of measurements and calculations includes helicopter-mode operation (performance, air loads, and blade structural loads), hover (performance and air loads), and airplane-mode operation (performance).

  11. International Space Station Configuration Analysis and Integration

    NASA Technical Reports Server (NTRS)

    Anchondo, Rebekah

    2016-01-01

    Ambitious engineering projects, such as NASA's International Space Station (ISS), require dependable modeling, analysis, visualization, and robotics to ensure that complex mission strategies are carried out cost effectively, sustainably, and safely. Learn how Booz Allen Hamilton's Modeling, Analysis, Visualization, and Robotics Integration Center (MAVRIC) team performs engineering analysis of the ISS Configuration based primarily on the use of 3D CAD models. To support mission planning and execution, the team tracks the configuration of ISS and maintains configuration requirements to ensure operational goals are met. The MAVRIC team performs multi-disciplinary integration and trade studies to ensure future configurations meet stakeholder needs.

  12. MATISSE-v2.0 infrared sea images: sensitivity analysis and experimental validation using MIRAMER campaign measurements in solar glint configurations.

    PubMed

    Fauqueux, Sandrine

    2013-08-20

    The validation of the multiresolution model of sea radiance in the infrared, developed at Onera, is investigated by comparison with measurements obtained during the MIRAMER campaign that took place in May 2008 in the Mediterranean Sea. The sea radiance model and optical properties are expressed and the experimental setup of the campaign is briefly presented. We focus on solar glint measurements collected on the 22nd of May at 5 h 59 m 50 s in the mid-wave IR (3.93-4.14 μm) band and the long-wave IR (8.19-8.96 μm) band onboard the research vessel (R/V) Atalante at a grazing observational angle. A sensitivity analysis of glitter radiance on atmospheric and aerosol profiles, as well as sea temperature and wind speed in the vicinity of the measured contextual parameters, is presented. Modeled and measured images are compared and results are delved into further by comparisons of histograms, averaged vertical and horizontal profiles. Errors in the 3.93-4.14 μm band are under those potentially due to calibration, whereas discrepancies are noticed in the 8.19-8.96 μm band, where the deepest analysis has to be performed.

  13. Experimental and theoretical analysis of organic dyes having a double D-π-A configurations for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Balanay, Mannix P.; Choi, Kyu-Seok; Lee, Sang Hee; Kim, Dong Hee

    2017-02-01

    Two spiro-like organic dyes linked at the thiophene bridge (KS-11 and KS-12) together with the original rod-shaped D-π-A configuration (C1) were designed, synthesized, and characterized based on their electronic structure, and determine the photophysical and photovoltaic properties for its application in dye-sensitized solar cells. Compared to C1, the double D-π-A spiro-like configuration, which consists of two separated light-harvesting moieties, was found to be beneficial to photocurrent generation provided that they are separated properly to prevent intramolecular exciton annihilation. This was observed when KS-11, which is linked at the β-position of the thiophene moiety of D-π-A, was compared with KS-12, where the two D-π-A are linked with an additional thiophene using a α-β linkage. The results show that KS-12 produced a 20% and 17% increase in photovoltaic efficiency under simulated AM 1.5G solar irradiation compared to KS-11 and C1, respectively. This increase in photovoltaic performance is credited mostly to the reduction of recombination effects and the increase in the density of states at the semiconductor surface due to high dye loading and better charge-transfer properties.

  14. An experimental study of several wind tunnel wall configurations using two V/STOL model configurations. [low speed wind tunnels

    NASA Technical Reports Server (NTRS)

    Binion, T. W., Jr.

    1975-01-01

    Experiments were conducted in the low speed wind tunnel using two V/STOL models, a jet-flap and a jet-in-fuselage configuration, to search for a wind tunnel wall configuration to minimize wall interference on V/STOL models. Data were also obtained on the jet-flap model with a uniform slotted wall configuration to provide comparisons between theoretical and experimental wall interference. A test section configuration was found which provided some data in reasonable agreement with interference-free results over a wide range of momentum coefficients.

  15. Contaminant plume configuration and movement: an experimental model

    NASA Astrophysics Data System (ADS)

    Alencoao, A.; Reis, A.; Pereira, M. G.; Liberato, M. L. R.; Caramelo, L.; Amraoui, M.; Amorim, V.

    2009-04-01

    The relevance of Science and Technology in our daily routines makes it compulsory to educate citizens who have both scientific literacy and scientific knowledge. These will allow them to be intervening citizens in a constantly changing society. Thus, physical and natural sciences are included in school curricula, both in primary and secondary education, with the fundamental aim of developing in the students the skills, attitudes and knowledge needed for the understanding of the planet Earth and its real problems. On the other hand, teaching in Geosciences is more and more based on practical methodologies which use didactic material, sustaining teachers' pedagogical practices and facilitating students' learning tasks suggested on the syllabus defined for each school level. Themes related to exploring the different components of the Hydrological Cycle and themes related to natural environment protection and preservation, namely water resources and soil contamination by industrial and urban sewage are examples of subject matters included on the Portuguese syllabus. These topics motivated the conception and construction of experimental models for the study of the propagation of pollutants on a porous medium. The experimental models allow inducing a horizontal flux of water though different kinds of permeable substances (e.g. sand, silt), with contamination spots on its surface. These experimental activities facilitate the student to understand the flow path of contaminating substances on the saturated zone and to observe the contaminant plume configuration and movement. The activities are explored in a teaching and learning process perspective where the student builds its own knowledge through real question- problem based learning which relate Science, Technology and Society. These activities have been developed in the framework of project ‘Water in the Environment' (CV/PVI/0854) of the POCTI Program (Programa Operacional "Ciência, Tecnologia, Inovação") financed

  16. Transonic Flow Field Analysis for Wing-Fuselage Configurations

    NASA Technical Reports Server (NTRS)

    Boppe, C. W.

    1980-01-01

    A computational method for simulating the aerodynamics of wing-fuselage configurations at transonic speeds is developed. The finite difference scheme is characterized by a multiple embedded mesh system coupled with a modified or extended small disturbance flow equation. This approach permits a high degree of computational resolution in addition to coordinate system flexibility for treating complex realistic aircraft shapes. To augment the analysis method and permit applications to a wide range of practical engineering design problems, an arbitrary fuselage geometry modeling system is incorporated as well as methodology for computing wing viscous effects. Configuration drag is broken down into its friction, wave, and lift induced components. Typical computed results for isolated bodies, isolated wings, and wing-body combinations are presented. The results are correlated with experimental data. A computer code which employs this methodology is described.

  17. Experimental transonic flutter characteristics of supersonic cruise configurations

    NASA Technical Reports Server (NTRS)

    Durham, Michael H.; Cole, Stanley R.; Cazier, F. W., Jr.; Keller, Donald F.; Parker, Ellen C.; Wilkie, W. Keats

    1990-01-01

    The flutter characteristics of a generic arrow-wing supersonic transport configuration are studied. The wing configuration has a 3 percent biconvex airfoil and a leading-edge sweep of 73 deg out to a cranked tip with a 60 deg leading-edge sweep. The ground vibration tests and flutter test procedure are described. The effects of flutter on engine nacelles, fuel loading, wing-mounted vertical fin, wing angle-of-attack, and wing tip mass and stiffness distributions are analyzed. The data reveal that engine nacelles reduce the transonic flutter dynamic pressure by 25-30 percent; fuel loadings decrease dynamic pressures by 25 percent; 4-6 deg wing angles-of-attack cause steep transonic boundaries; and 5-10 percent changes in flutter dynamic pressures are the result of the wing-mounted vertical fin and wing-tip mass and stiffness distributions.

  18. Experimental Configuration Effects on ICE Tumble Flow Evaluation

    NASA Astrophysics Data System (ADS)

    Santana, Bryan; Puzinauskas, Paulius

    2014-11-01

    The generation of ICE (Internal Combustion Engine) in-cylinder charge motions, such as swirl and tumble, have shown positive effects on reducing fuel consumption and exhaust emission levels at partial engine loads. Tumble flow is commonly measured utilizing a steady-flow rig and two-dimensional PIV (Particle Image Velocimetry) systems, among others. In order to optimize the tumble flow, it is important to retrieve accurate measurements. The tumble flow values could be affected by variations in the geometry and/or design of the steady-flow rig utilized during flow tests. In this research, a four-valve per cylinder head was tested on a steady flow bench, varying several aspects of the configuration to evaluate how they influence bulk momentum as well as PIV measurements. The configuration variations included symmetrical, asymmetrical and runner-fed configurations throughout testing. Volumetric flow rate and tumble strength flow measurements were retrieved at the selected L/D ratios. Additionally, several PIV seeding particles were characterized for size and shape. Corresponding PIV flow measurements using each type of seeding were made to evaluate how the particles influence the results. NSF ECE Grant #1358991 supported Bryan Santana Rivera as an REU student.

  19. An Analysis of Naval Aviation Configuration Status Accounting.

    DTIC Science & Technology

    1983-12-01

    R -A41O 473 AN ANALYSIS OF NAVAL AVIATION CONFIGURATION STATUS 1/2 ACCOUNTING (U) NAVAL POSTGRADUATE SCHOOL MONTEREY CR M A SNYDER ET AL. DEC 83...THESIS "S AN ANALYSIS OF NAVAL AVIATION CONFIGURATION STATUS ACCOUNTING by ____ Marlene A. Snyder -... ,and C..) Thomas F. Snyder 4/ December 1983 Thesis...NUMBER 4. TITLE (and Aejt11a) 5. TYPE OF REPORT & PERIOD COVERED An Analysis of Naval Aviation Master’s Thesis Configuration Status Accounting December

  20. Experimental beta limits of symmetric linear heliac configurations

    SciTech Connect

    Spanjers, G.G.; Nelson, B.A.; Ribe, F.L.; Jarboe, T.R. )

    1994-08-01

    Helically symmetric heliac equilibria [H. P. Furth, [ital Plasma] [ital Physics] [ital and] [ital Controlled] [ital Fusion] [ital Research] (International Atomic Energy Agency, Vienna, 1966), Vol. 1, p. 103] are formed on the High Beta Q Machine (HBQM) [C. M. Greenfield, Phys. Fluids B [bold 2], 133 (1990)] by using a fast-rising central conductor (hardcore) current in conjunction with a shock-heated [ital l]=1 stellarator configuration. The equilibria are found to possess a high global beta and the plasma pressure is approximately a flux-surface quantity. Under the effects of plasma, the magnetic well is found to deepen and the rotational transform is greatly increased and becomes highly sheared, owing to plasma currents induced by the fast-rising hardcore current. In the second phase of the experiment, the equilibrium fields of the symmetric heliac are lowered while maintaining the same shock heating in an attempt to raise the global beta. No substantial change in global beta is seen, indicating that the configuration forms at the beta limit in the shock-heated HBQM, and that the plasma beta seen in the first phase of the experiment is the symmetric heliac beta limit.

  1. CRANS - CONFIGURABLE REAL-TIME ANALYSIS SYSTEM

    NASA Technical Reports Server (NTRS)

    Mccluney, K.

    1994-01-01

    In a real-time environment, the results of changes or failures in a complex, interconnected system need evaluation quickly. Tabulations showing the effects of changes and/or failures of a given item in the system are generally only useful for a single input, and only with regard to that item. Subsequent changes become harder to evaluate as combinations of failures produce a cascade effect. When confronted by multiple indicated failures in the system, it becomes necessary to determine a single cause. In this case, failure tables are not very helpful. CRANS, the Configurable Real-time ANalysis System, can interpret a logic tree, constructed by the user, describing a complex system and determine the effects of changes and failures in it. Items in the tree are related to each other by Boolean operators. The user is then able to change the state of these items (ON/OFF FAILED/UNFAILED). The program then evaluates the logic tree based on these changes and determines any resultant changes to other items in the tree. CRANS can also search for a common cause for multiple item failures, and allow the user to explore the logic tree from within the program. A "help" mode and a reference check provide the user with a means of exploring an item's underlying logic from within the program. A commonality check determines single point failures for an item or group of items. Output is in the form of a user-defined matrix or matrices of colored boxes, each box representing an item or set of items from the logic tree. Input is via mouse selection of the matrix boxes, using the mouse buttons to toggle the state of the item. CRANS is written in C-language and requires the MIT X Window System, Version 11 Revision 4 or Revision 5. It requires 78K of RAM for execution and a three button mouse. It has been successfully implemented on Sun4 workstations running SunOS, HP9000 workstations running HP-UX, and DECstations running ULTRIX. No executable is provided on the distribution medium; however

  2. CRANS - CONFIGURABLE REAL-TIME ANALYSIS SYSTEM

    NASA Technical Reports Server (NTRS)

    Mccluney, K.

    1994-01-01

    In a real-time environment, the results of changes or failures in a complex, interconnected system need evaluation quickly. Tabulations showing the effects of changes and/or failures of a given item in the system are generally only useful for a single input, and only with regard to that item. Subsequent changes become harder to evaluate as combinations of failures produce a cascade effect. When confronted by multiple indicated failures in the system, it becomes necessary to determine a single cause. In this case, failure tables are not very helpful. CRANS, the Configurable Real-time ANalysis System, can interpret a logic tree, constructed by the user, describing a complex system and determine the effects of changes and failures in it. Items in the tree are related to each other by Boolean operators. The user is then able to change the state of these items (ON/OFF FAILED/UNFAILED). The program then evaluates the logic tree based on these changes and determines any resultant changes to other items in the tree. CRANS can also search for a common cause for multiple item failures, and allow the user to explore the logic tree from within the program. A "help" mode and a reference check provide the user with a means of exploring an item's underlying logic from within the program. A commonality check determines single point failures for an item or group of items. Output is in the form of a user-defined matrix or matrices of colored boxes, each box representing an item or set of items from the logic tree. Input is via mouse selection of the matrix boxes, using the mouse buttons to toggle the state of the item. CRANS is written in C-language and requires the MIT X Window System, Version 11 Revision 4 or Revision 5. It requires 78K of RAM for execution and a three button mouse. It has been successfully implemented on Sun4 workstations running SunOS, HP9000 workstations running HP-UX, and DECstations running ULTRIX. No executable is provided on the distribution medium; however

  3. An alternative experimental approach for subcritical configurations of the IPEN/MB-01 nuclear reactor

    NASA Astrophysics Data System (ADS)

    Gonnelli, E.; Lee, S. M.; Pinto, L. N.; Landim, H. R.; Diniz, R.; Jerez, R.; dos Santos, A.

    2015-07-01

    This work presents an alternative approach for the reactivity worth experiments analysis in the IPEN/MB-01 reactor considering highly subcritical arrays. In order to reach the subcritical levels, the removal of a specific number of fuel rods is proposed. Twenty three configurations were carried out for this purpose. The control bank insertion experiment was used only as reference for the fuel rod experiment and, in addition, the control banks were maintained completely withdrawn during all the fuel rods experiment. The theoretical simulation results using the MCNP5 code and the ENDF/B-VII.0 library neutron data are in a very good agreement to experimental results.

  4. Experimental evidence of skyrmion-like configurations in bilayer nanodisks with perpendicular magnetic anisotropy

    SciTech Connect

    Stebliy, Maxim E. Kolesnikov, Alexander G.; Davydenko, Alexander V.; Ognev, Alexey V.; Samardak, Alexander S.; Chebotkevich, Ludmila A.

    2015-05-07

    Formation and existence of magnetic skyrmion-like configurations in bilayer nanodisks (Ta(3 nm)/[Co(0.37 nm)/Ni(0.58 nm)]{sub 10}){sub 2} with perpendicular magnetic anisotropy are shown experimentally at room temperature. Magnetization reversal through the skyrmion state is studied using magnetic hysteresis measurements. An evolution of skyrmion configurations in the nanodisk structure is analyzed. Experimental methods and micromagnetic simulations help to understand the magnetization reversal processes occurring through the stable skyrmion-like configurations. Formation of the intermediate C-states during magnetization reversal is demonstrated. The skyrmion number for all possible spin configurations is calculated.

  5. CMS Configuration Editor: GUI based application for user analysis job

    NASA Astrophysics Data System (ADS)

    de Cosa, A.

    2011-12-01

    We present the user interface and the software architecture of the Configuration Editor for the CMS experiment. The analysis workflow is organized in a modular way integrated within the CMS framework that organizes in a flexible way user analysis code. The Python scripting language is adopted to define the job configuration that drives the analysis workflow. It could be a challenging task for users, especially for newcomers, to develop analysis jobs managing the configuration of many required modules. For this reason a graphical tool has been conceived in order to edit and inspect configuration files. A set of common analysis tools defined in the CMS Physics Analysis Toolkit (PAT) can be steered and configured using the Config Editor. A user-defined analysis workflow can be produced starting from a standard configuration file, applying and configuring PAT tools according to the specific user requirements. CMS users can adopt this tool, the Config Editor, to create their analysis visualizing in real time which are the effects of their actions. They can visualize the structure of their configuration, look at the modules included in the workflow, inspect the dependences existing among the modules and check the data flow. They can visualize at which values parameters are set and change them according to what is required by their analysis task. The integration of common tools in the GUI needed to adopt an object-oriented structure in the Python definition of the PAT tools and the definition of a layer of abstraction from which all PAT tools inherit.

  6. Experimental and analytical investigations of sleeved pipeline configurations

    SciTech Connect

    Hart, J.D.; Powell, G.H.; Rinawi, A.K.

    1995-12-31

    A series of buckling experiments has been conducted on 60 foot long 48-inch diameter sleeved pipe specimens at Southwest Research Institute in San Antonio, Texas. The tests included the application of internal pressure and axial force to simulate fully restrained conditions, followed by the application of four-point bending loads up to and beyond wrinkling of the specimens. The results from the first two of these tests are presented together with results from analytical correlation studies in which the tests were simulated using beam bending models. The comparisons show close agreement between the analyses and the experiments, provided that (a) anisotropy of the steel properties is accounted for and (b) a special wrinkling segment is included in the bending models. It is concluded that the analytical approach can be used with a substantial degree of confidence to analyze pipeline configurations up to the point of incipient wrinkling.

  7. USM3D Analysis of Low Boom Configuration

    NASA Technical Reports Server (NTRS)

    Carter, Melissa B.; Campbell, Richard L.; Nayani, Sudheer N.

    2011-01-01

    In the past few years considerable improvement was made in NASA's in house boom prediction capability. As part of this improved capability, the USM3D Navier-Stokes flow solver, when combined with a suitable unstructured grid, went from accurately predicting boom signatures at 1 body length to 10 body lengths. Since that time, the research emphasis has shifted from analysis to the design of supersonic configurations with boom signature mitigation In order to design an aircraft, the techniques for accurately predicting boom and drag need to be determined. This paper compares CFD results with the wind tunnel experimental results conducted on a Gulfstream reduced boom and drag configuration. Two different wind-tunnel models were designed and tested for drag and boom data. The goal of this study was to assess USM3D capability for predicting both boom and drag characteristics. Overall, USM3D coupled with a grid that was sheared and stretched was able to reasonably predict boom signature. The computational drag polar matched the experimental results for a lift coefficient above 0.1 despite some mismatch in the predicted lift-curve slope.

  8. Flammability Configuration Analysis for Spacecraft Applications

    NASA Technical Reports Server (NTRS)

    Pedley, Michael D.

    2014-01-01

    Fire is one of the many potentially catastrophic hazards associated with the operation of crewed spacecraft. A major lesson learned by NASA from the Apollo 204 fire in 1966 was that ignition sources in an electrically powered vehicle should and can be minimized, but can never be eliminated completely. For this reason, spacecraft fire control is based on minimizing potential ignition sources and eliminating materials that can propagate fire. Fire extinguishers are always provided on crewed spacecraft, but are not considered as part of the fire control process. "Eliminating materials that can propagate fire" does not mean eliminating all flammable materials - the cost of designing and building spacecraft using only nonflammable materials is extraordinary and unnecessary. It means controlling the quantity and configuration of such materials to eliminate potential fire propagation paths and thus ensure that any fire would be small, localized, and isolated, and would self-extinguish without harm to the crew. Over the years, NASA has developed many solutions for controlling the configuration of flammable materials (and potentially flammable materials in commercial "off-the-shelf" hardware) so that they can be used safely in air and oxygen-enriched environments in crewed spacecraft. This document describes and explains these design solutions so payload customers and other organizations can use them in designing safe and cost-effective flight hardware. Proper application of these guidelines will produce acceptable flammability configurations for hardware located in any compartment of the International Space Station or other program crewed vehicles and habitats. However, use of these guidelines does not exempt hardware organizations of the responsibility for safety of the hardware under their control.

  9. Comparative analysis of alternate MHS configurations

    NASA Technical Reports Server (NTRS)

    Cabrera-Mercader, Carlos R.; Staelin, David H.

    1995-01-01

    Given the possibility that the passive Microwave Humidity Sounder (MHS) for NASA's Earth Observing System (EOS) may have to be replaced, two alternate configurations are analyzed in this document. One option mirrors AMSU-B, the Advanced Microwave Sounding Unit (AMSU) moisture sounder; which consists of five channels at 89, 150, 183 +/- 1, 183 +/- 3, and 183 +/- 7 GHz. The second option contains an additional channel at 183 +/- 14 GHz and replaces the channels at 89 and 150 GHz with three channels at 118 +/- 0.5, 118 +/- 1.4, and 118 +/- 3 GHz. The latter configuration is considered to be superior due to its greater scientific benefits and reduced cost and complexity -- it would require only two local oscillators and a smaller antenna size for a given resolution on the ground. As shown by means of simulations, humidity profile retrieval accuracy for the second option is superior in most cases and only slightly degraded relative to the first option in the worst-case scenario. The results are summarized. Including the 118-GHz channels also offers the possibility of cell-top altitude retrievals and improved temperature profile retrievals when used in conjunction with a temperature sounder such as the 15-channel AMSU-A.

  10. Experimental studies of linear high-beta heliac plasma configurations

    SciTech Connect

    Greenfield, C.M.; Koepke, M.E.; Ribe, F.L. )

    1990-01-01

    The formation and quasi-equilibrium of a high-beta heliac plasma are investigated in the High-Beta Q Machine (Phys. Fluids {bold 30}, 2885 (1987)), a linear high-beta {ital l}=1 stellarator with an internal current carrying conductor (hardcore). The hardcore current rise time is varied from 9 {mu}sec to smaller values comparable with that of the main compression field (450 nsec). Flux contours and plasma pressure calculated from internal magnetic-probe measurements are used to distinguish between nearly axisymmetric plasma confined near the hardcore and the heliac plasma confined near the magnetic axis. For the shorter hardcore rise times, the axisymmetric plasma pressure becomes small compared to that of the heliac. Further analysis of the data allows calculation of the currents flowing in the plasma, the rotational transform, and the magnetic well depth. Appreciable axial current is observed, consistent with induction by the changing magnetic fields during the heliac formation. The observed relationship between the axial current and rotational transform is confirmed by computer modeling using the HASE magnetohydrodynamic equilibrium code (Nucl. Fusion {bold 23}, 1061 (1983)).

  11. Selectivity evaluation for two experimental gill-net configurations used to sample Lake Erie walleyes

    USGS Publications Warehouse

    Vandergoot, Christopher S.; Kocovsky, Patrick M.; Brenden, Travis O.; Liu, Weihai

    2011-01-01

    We used length frequencies of captured walleyes Sander vitreus to indirectly estimate and compare selectivity between two experimental gill-net configurations used to sample fish in Lake Erie: (1) a multifilament configuration currently used by the Ohio Department of Natural Resources (ODNR) with stretched-measure mesh sizes ranging from 51 to 127 mm and a constant filament diameter (0.37 mm); and (2) a monofilament configuration with mesh sizes ranging from 38 to 178 mm and varying filament diameter (range = 0.20–0.33 mm). Paired sampling with the two configurations revealed that the catch of walleyes smaller than 250 mm and larger than 600 mm was greater in the monofilament configuration than in the multifilament configuration, but the catch of 250–600-mm fish was greater in the multifilament configuration. Binormal selectivity functions yielded the best fit to observed walleye catches for both gill-net configurations based on model deviances. Incorporation of deviation terms in the binormal selectivity functions (i.e., to relax the assumption of geometric similarity) further improved the fit to observed catches. The final fitted selectivity functions produced results similar to those from the length-based catch comparisons: the monofilament configuration had greater selectivity for small and large walleyes and the multifilament configuration had greater selectivity for mid-sized walleyes. Computer simulations that incorporated the fitted binormal selectivity functions indicated that both nets were likely to result in some bias in age composition estimates and that the degree of bias would ultimately be determined by the underlying condition, mortality rate, and growth rate of the Lake Erie walleye population. Before the ODNR switches its survey gear, additional comparisons of the different gill-net configurations, such as fishing the net pairs across a greater range of depths and at more locations in the lake, should be conducted to maintain congruence in

  12. The MIRTE Experimental Program: An Opportunity to Test Structural Materials in Various Configurations in Thermal Energy Spectrum

    SciTech Connect

    Leclaire, Nicolas; Le Dauphin, Francois-Xavier; Duhamel, Isabelle; Briggs, Blair; Piot, Jerome; Rennesson, Malvina; Laville, Arnaud

    2014-11-04

    The MIRTE (Materials in Interacting and Reflecting configurations, all Thicknesses) program was established to answer the needs of criticality safety practitioners in terms of experimental validation of structural materials and to possibly contribute to nuclear data improvement, which ultimately supports reactor safety analysis as well. MIRTE took the shape of a collaboration between the AREVA and ANDRA French industrialists and a noncommercial international funding partner such as the U.S. Department of Energy. The aim of this paper is to present the configurations of the MIRTE 1 and MIRTE 2 programs and to highlight the results of the titanium experiments recently published in the International Handbook of Evaluated Criticality Safety Benchmark Experiments.

  13. Experimental and numerical study of a dual configuration for a flapping tidal current generator.

    PubMed

    Kim, Jihoon; Quang Le, Tuyen; Hwan Ko, Jin; Ebenezer Sitorus, Patar; Hartarto Tambunan, Indra; Kang, Taesam

    2015-07-30

    In this study, we conduct experimental and consecutive numerical analyses of a flapping tidal current generator with a mirror-type dual configuration with front-swing and rear-swing flappers. An experimental analysis of a small-scale prototype is conducted in a towing tank, and a numerical analysis is conducted by means of two-dimensional computational fluid dynamics simulations with an in-house code. An experimental study with a controller to determine the target arm angle shows that the resultant arm angle is dependent on the input arm angle, the frequency, and the applied load, while a high pitch is obtained simply with a high input arm angle. Through a parametric analysis conducted while varying these factors, a high applied load and a high input arm angle were found to be advantageous. Moreover, the optimal reduced frequency was found to be 0.125 in terms of the power extraction. In consecutive numerical investigations with the kinematics selected from the experiments, it was found that a rear-swing flapper contributes to the total amount of power more than a front-swing flapper with a distance of two times the chord length and with a 90° phase difference between the two. The high contribution stems from the high power generated by the rear-swing flapper, which mimics the tail fin movement of a dolphin along a flow, compared to a plunge system or a front-swing system, which mimics the tail fin movement of a dolphin against a flow. It is also due to the fact that the shed vorticities of the front-swing flapper slightly affect negatively or even positively the power performance of the rear-swing system at a given distance and phase angle.

  14. Molecular dynamics simulation of configurational ensembles compatible with experimental FRET efficiency data through a restraint on instantaneous FRET efficiencies.

    PubMed

    Reif, Maria M; Oostenbrink, Chris

    2014-12-15

    Förster resonance energy transfer (FRET) measurements are widely used to investigate (bio)molecular interactions or/and association. FRET efficiencies, the primary data obtained from this method, give, in combination with the common assumption of isotropic chromophore orientation, detailed insight into the lengthscale of molecular phenomena. This study illustrates the application of a FRET efficiency restraint during classical atomistic molecular dynamics simulations of a mutant mastoparan X peptide in either water or 7 M aqueous urea. The restraint forces acting on the donor and acceptor chromophores ensure that the sampled peptide configurational ensemble satisfies the experimental primary data by modifying interchromophore separation and chromophore transition dipole moment orientations. By means of a conformational cluster analysis, it is seen that indeed different configurational ensembles may be sampled without and with application of the restraint. In particular, while the FRET efficiency and interchromophore distances monitored in an unrestrained simulation may differ from the experimentally-determined values, they can be brought in agreement with experimental data through usage of the FRET efficiency restraining potential. Furthermore, the present results suggest that the assumption of isotropic chromophore orientation is not always justified. The FRET efficiency restraint allows the generation of configurational ensembles that may not be accessible with unrestrained simulations, and thereby supports a meaningful interpretation of experimental FRET results in terms of the underlying molecular degrees of freedom. Thus, it offers an additional tool to connect the realms of computer and wet-lab experimentation.

  15. What carries a mediation process? Configural analysis of mediation.

    PubMed

    von Eye, Alexander; Mun, Eun Young; Mair, Patrick

    2009-09-01

    Mediation is a process that links a predictor and a criterion via a mediator variable. Mediation can be full or partial. This well-established definition operates at the level of variables even if they are categorical. In this article, two new approaches to the analysis of mediation are proposed. Both of these approaches focus on the analysis of categorical variables. The first involves mediation analysis at the level of configurations instead of variables. Thus, mediation can be incorporated into the arsenal of methods of analysis for person-oriented research. Second, it is proposed that Configural Frequency Analysis (CFA) can be used for both exploration and confirmation of mediation relationships among categorical variables. The implications of using CFA are first that mediation hypotheses can be tested at the level of individual configurations instead of variables. Second, this approach leaves the door open for different types of mediation processes to exist within the same set. Using a data example, it is illustrated that aggregate-level analysis can overlook mediation processes that operate at the level of individual configurations.

  16. Experimental Sonic Boom Measurements on a Mach 1.6 Cruise Low-Boom Configuration

    NASA Technical Reports Server (NTRS)

    Wilcox, Floyd J., Jr.; Elmiligui, Alaa, A.; Wayman, Thomas R.; Waithe, Kenrick A.; Howe, Donald C.; Bangert, Linda S.

    2012-01-01

    A wind tunnel test has been conducted by Gulfstream Aerospace Corporation (GAC) to measure the sonic boom pressure signature of a low boom Mach 1.6 cruise business jet in the Langley Unitary Plan Wind Tunnel at Mach numbers 1.60 and 1.80. Through a cooperative agreement between GAC and the National Aeronautics and Space Administration (NASA), GAC provided NASA access to some of the experimental data and NASA is publishing these data for the sonic boom research community. On-track and off-track near field sonic boom pressure signatures were acquired at three separation distances (0.5, 1.2, and 1.7 reference body lengths) and three angles of attack (-0.26deg, 0.26deg, and 0.68deg). The model was blade mounted to minimize the sting effects on the sonic boom signatures. Although no extensive data analysis is provided, selected data are plotted to illustrate salient features of the data. All of the experimental sonic boom pressure data are tabulated. Schlieren images of the configuration are also included.

  17. An Experimental Investigation of the Flow Over the Rear End of a Notchback Automobile Configuration

    NASA Technical Reports Server (NTRS)

    Jenkins, Luther N.

    2000-01-01

    An experimental investigation of the flow over the rear end of a 0.16 scale notchback automobile configuration has been conducted in the NASA Langley Basic Aerodynamics Research Tunnel (BART). The objective of this work was to investigate the flow separation that occurs behind the backlight and obtain experimental data that can be used to understand the physics and time-averaged structure of the flow field. A three-component laser velocimeter was used to make non-intrusive, velocity measurements in the center plane and in a single cross-flow plane over the decklid. In addition to off-body measurements, flow conditions on the car surface were documented via surface flow visualization, boundary layer measurements, and surface pressures. The experimental data show several features previously identified by other researchers, but also reveal differences between the flow field associated with this particular configuration and the generally accepted models for the flow over a notchback rear end.

  18. Cost benefit analysis on different configurations of berthing structure

    NASA Astrophysics Data System (ADS)

    Rajesh, G.; Saravanan, R.; Ravichandran, Vijaya; Parameswara Pandian, S.; Ramani Sujatha, Evangelin

    2017-07-01

    Port and harbors are essential for handling of the imports/exports of good transported through shipping. This paper discusses the different configuration of berthing structure, their design with respect to the site conditions and suitability. The analysis includes detailed load calculations conforming to the various codal provisions and design of the structure. The configuration of berthing structure considered are analyzed and designed using STAAD Pro for different combination of loads as per IS 4651. Bill of Quantities are prepared and final cost of construction is calculated. Factors affecting the construction and maintenance such as land availability, soil conditions, hydrodynamics of the site, dredging requirements, design ship size etc. are considered to finalize the configuration of the berthing structure. Result of the study shows that Diaphragm wall type of berthing structure is economic for Ennore port.

  19. Nonlinear High Fidelity Aeroelastic Analysis for Novel Configurations

    DTIC Science & Technology

    2010-03-29

    structural nonlinearities are stronger than aerodynamic nonlinearities for the cases studied. Aeroelasticity, morphing wings , folding wings , flutter...2004. 4Snyder, M., Frank, G., and Sanders, B., “Aeroelastic Analysis of a Morphing Z- Wing Configuration,” Aerospace Flutter and Dynamics Council...finite element analysis and component synthesis and the aerodynamic model is discretized using a vortex lattice. Results from the computational model

  20. Propfan experimental data analysis

    NASA Technical Reports Server (NTRS)

    Vernon, David F.; Page, Gregory S.; Welge, H. Robert

    1984-01-01

    A data reduction method, which is consistent with the performance prediction methods used for analysis of new aircraft designs, is defined and compared to the method currently used by NASA using data obtained from an Ames Res. Center 11 foot transonic wind tunnel test. Pressure and flow visualization data from the Ames test for both the powered straight underwing nacelle, and an unpowered contoured overwing nacelle installation is used to determine the flow phenomena present for a wind mounted turboprop installation. The test data is compared to analytic methods, showing the analytic methods to be suitable for design and analysis of new configurations. The data analysis indicated that designs with zero interference drag levels are achieveable with proper wind and nacelle tailoring. A new overwing contoured nacelle design and a modification to the wing leading edge extension for the current wind tunnel model design are evaluated. Hardware constraints of the current model parts prevent obtaining any significant performance improvement due to a modified nacelle contouring. A new aspect ratio wing design for an up outboard rotation turboprop installation is defined, and an advanced contoured nacelle is provided.

  1. Structural Configuration Systems Analysis for Advanced Aircraft Fuselage Concepts

    NASA Technical Reports Server (NTRS)

    Mukhopadhyay, Vivek; Welstead, Jason R.; Quinlan, Jesse R.; Guynn, Mark D.

    2016-01-01

    Structural configuration analysis of an advanced aircraft fuselage concept is investigated. This concept is characterized by a double-bubble section fuselage with rear mounted engines. Based on lessons learned from structural systems analysis of unconventional aircraft, high-fidelity finite-element models (FEM) are developed for evaluating structural performance of three double-bubble section configurations. Structural sizing and stress analysis are applied for design improvement and weight reduction. Among the three double-bubble configurations, the double-D cross-section fuselage design was found to have a relatively lower structural weight. The structural FEM weights of these three double-bubble fuselage section concepts are also compared with several cylindrical fuselage models. Since these fuselage concepts are different in size, shape and material, the fuselage structural FEM weights are normalized by the corresponding passenger floor area for a relative comparison. This structural systems analysis indicates that an advanced composite double-D section fuselage may have a relative structural weight ratio advantage over a conventional aluminum fuselage. Ten commercial and conceptual aircraft fuselage structural weight estimates, which are empirically derived from the corresponding maximum takeoff gross weight, are also presented and compared with the FEM- based estimates for possible correlation. A conceptual full vehicle FEM model with a double-D fuselage is also developed for preliminary structural analysis and weight estimation.

  2. Granger causality--statistical analysis under a configural perspective.

    PubMed

    von Eye, Alexander; Wiedermann, Wolfgang; Mun, Eun-Young

    2014-03-01

    The concept of Granger causality can be used to examine putative causal relations between two series of scores. Based on regression models, it is asked whether one series can be considered the cause for the second series. In this article, we propose extending the pool of methods available for testing hypotheses that are compatible with Granger causation by adopting a configural perspective. This perspective allows researchers to assume that effects exist for specific categories only or for specific sectors of the data space, but not for other categories or sectors. Configural Frequency Analysis (CFA) is proposed as the method of analysis from a configural perspective. CFA base models are derived for the exploratory analysis of Granger causation. These models are specified so that they parallel the regression models used for variable-oriented analysis of hypotheses of Granger causation. An example from the development of aggression in adolescence is used. The example shows that only one pattern of change in aggressive impulses over time Granger-causes change in physical aggression against peers.

  3. Structural Configuration Analysis of Crew Exploration Vehicle Concepts

    NASA Technical Reports Server (NTRS)

    Mukhopadhyay, V.

    2006-01-01

    Structural configuration modeling and finite element analysis of crew exploration vehicle (CEV) concepts are presented. In the structural configuration design approach, parametric solid models of the pressurized shell and tanks are developed. The CEV internal cabin pressure is same as in the International Space Station (ISS) to enable docking with the ISS without an intermediate airlock. Effects of this internal pressure load on the stress distribution, factor of safety, mass and deflections are investigated. Uniform 7 mm thick skin shell, 5 mm thick shell with ribs and frames, and isogrid skin construction options are investigated. From this limited study, the isogrid construction appears to provide most strength/mass ratio. Initial finite element analysis results on the service module tanks are also presented. These rapid finite element analyses, stress and factor of safety distribution results are presented as a part of lessons learned and to build up a structural mass estimation and sizing database for future technology support. This rapid structural analysis process may also facilitate better definition of the vehicles and components for rapid prototyping. However, these structural analysis results are highly conceptual and exploratory in nature and do not reflect current configuration designs being conducted at the program level by NASA and industry.

  4. Analysis of electromagnetic backscatter from an inlet cavity configuration

    NASA Astrophysics Data System (ADS)

    Pathak, P. H.; Huang, C. C.; Lai, C. Y.; Moffatt, D. L.

    1983-01-01

    The radar cross secction of jet engine configurations on modern aircraft is a most perverse problem analytically. An ability to predict the radar cross section of loaded cavity structures, even when such structures are only very crude models of the actual engine, has been seriously lacking. At the same time it is well known that above a certain spectral range the engine configuration largely controls the radar cross section of the aircraft over a large span of noise and often stern aspects. Recently, the radar signal modulation produced by the engines has become of important analytical concern. This report is separated into two parts. Part I, Ray Analysis of EM Backscatter from a Cavity Configuration contains the major thrust of our research and basically details an asymptotic frequency domain analysis of various loaded cavity structures. Part II, Canonical Response Waveforms of Finite and Open Circular Waveguides is essentially a time domain analysis of the same types of problems. The parts are interrelated in the sense that results from one are used in the other. For example, Part II reproduces a portion of the exact Wiener-Hopf computations for an open circular waveguide. These results were used to verify a portion of the theory in Part I. Conversely, frequency computations from the analysis in Part I are used in Part II as part of a Fourier synthesis procedure to obtain canonical response waveforms.

  5. Analysis of transonic flow about lifting wing-body configurations

    NASA Technical Reports Server (NTRS)

    Barnwell, R. W.

    1975-01-01

    An analytical solution was obtained for the perturbation velocity potential for transonic flow about lifting wing-body configurations with order-one span-length ratios and small reduced-span-length ratios and equivalent-thickness-length ratios. The analysis is performed with the method of matched asymptotic expansions. The angles of attack which are considered are small but are large enough to insure that the effects of lift in the region far from the configuration are either dominant or comparable with the effects of thickness. The modification to the equivalence rule which accounts for these lift effects is determined. An analysis of transonic flow about lifting wings with large aspect ratios is also presented.

  6. Transonic analysis of complex configurations using TRANAIR program

    NASA Technical Reports Server (NTRS)

    Saaris, G. R.; Gilkey, R. D.; Smit, K. L.; Tinoco, E. N.

    1989-01-01

    The application of a three-dimensional transonic flow analysis method, TRANAIR, is explored from the point of view of a user. Detailed features of the program are outlined to give a better understanding of capability. Numerous results are presented to show some of the complex configurations which have been analyzed. In particular, examples are provided which show the application to turbofan engine installation on transport aircraft.

  7. Analysis of conventional and asymmetric aircraft configurations using CEASIOM

    NASA Astrophysics Data System (ADS)

    Richardson, Thomas S.; McFarlane, Cormac; Isikveren, Askin; Badcock, Ken; Da Ronch, Andrea

    2011-11-01

    One of the main drivers behind the SimSAC project and the CEASIOM software is to bring stability analysis and control system design earlier into the aircraft conceptual design process. Within this paper two very different aircraft are considered, a conventional T-tail based on the existing EA500 Very Light Jet and the second, a novel Z-wing configuration known as the GAV or general aviation vehicle. The first aircraft serves as a baseline comparison for the second, and the cruise case is considered as a benchmark for identifying potential drag reductions and aircraft stability characteristics. CEASIOM, the Computerised Environment for Aircraft Synthesis and Integrated Optimisation Methods, is used to generate aerodynamic data sets for both aircraft, create trim conditions and the associated linear models for classical stability analysis. The open-loop Z-wing configuration is shown to display both highly unstable and coupled modes before a multivariable Stability Augmentation System (SAS) is applied both to decouple and stabilise the aircraft. Within this paper, these two aircraft provide a test case with which to demonstrate the capabilities of the CEASIOM environment and the tools which have been developed during the SimSAC project. This new software suite is shown to allow conceptual development of unconventional novel configurations from mass properties through adaptive-fidelity aerodynamics to linear analysis and control system design.

  8. Numerical analysis of the dynamics of distributed vortex configurations

    NASA Astrophysics Data System (ADS)

    Govorukhin, V. N.

    2016-08-01

    A numerical algorithm is proposed for analyzing the dynamics of distributed plane vortex configurations in an inviscid incompressible fluid. At every time step, the algorithm involves the computation of unsteady vortex flows, an analysis of the configuration structure with the help of heuristic criteria, the visualization of the distribution of marked particles and vorticity, the construction of streamlines of fluid particles, and the computation of the field of local Lyapunov exponents. The inviscid incompressible fluid dynamic equations are solved by applying a meshless vortex method. The algorithm is used to investigate the interaction of two and three identical distributed vortices with various initial positions in the flow region with and without the Coriolis force.

  9. Experimental and analytical transonic flutter characteristics of a geared-elevator configuration

    NASA Technical Reports Server (NTRS)

    Ruhlin, C. L.; Doggett, R. V., Jr.; Gregory, R. A.

    1980-01-01

    The flutter model represented the aft fuselage and empennage of a proposed supersonic transport airplane and had an all movable horizontal tail with a geared elevator. It was tested mounted from a sting in the transonic dynamics tunnel. Symmetric flutter boundaries were determined experimentally at Mach numbers from 0.7 to 1.14 for a geared elevator configuration (gear ratio of 2.8 to 1.0) and an ungeared elevator configuration (gear ratio of 1.0 to 1.0). Gearing the elevator increased the experimental flutter dynamic pressures about 20 percent. Flutter calculations were made for the geared elevator configuration by using two analytical methods based on subsonic lifting surface theory. Both methods analyzed the stabilizer and elevator as a single, deforming surface, but one method also allowed the elevator to be analyzed as hinged from the stabilizer. All analyses predicted lower flutter dynamic pressures than experiment with best agreement (within 12 percent) for the hinged elevator method. Considering the model as mounted from a flexible rather than rigid sting in the analyses, had only a slight effect on the flutter results but was significant in that a sting related vibration mode was identified as a potentially flutter critical mode.

  10. A comparative study of behaviors of ventilated supercavities between experimental models with different mounting configurations

    NASA Astrophysics Data System (ADS)

    Lee, Seung-Jae; Kawakami, Ellison; Karn, Ashish; Arndt, Roger E. A.

    2016-08-01

    Small-scale water tunnel experiments of the phenomenon of supercavitation can be carried out broadly using two different kinds of experimental models-in the first model (forward facing model, or FFM), the incoming flow first interacts with the cavitator at front, which is connected to the strut through a ventilation pipe. The second model could have the strut and the ventilation pipe preceding the cavitator (backward facing model, or BFM). This is the continuation of a water tunnel study of the effects of unsteady flows on axisymmetric supercavities. In this study, the unwanted effect of test model configuration on supercavity shape in periodic flows was explored through a comparison of FFM and BFM models. In our experiments, it was found that periodic gust flows have only a minimal effect on the maximum diameter and the cavity length can be shortened above a certain vertical velocity of periodic flows. These findings appear to be robust regardless of the model configuration.

  11. Experimental investigation on the characteristics of supersonic fuel spray and configurations of induced shock waves

    PubMed Central

    Wang, Yong; Yu, Yu-song; Li, Guo-xiu; Jia, Tao-ming

    2017-01-01

    The macro characteristics and configurations of induced shock waves of the supersonic sprays are investigated by experimental methods. Visualization study of spray shape is carried out with the high-speed camera. The macro characteristics including spray tip penetration, velocity of spray tip and spray angle are analyzed. The configurations of shock waves are investigated by Schlieren technique. For supersonic sprays, the concept of spray front angle is presented. Effects of Mach number of spray on the spray front angle are investigated. The results show that the shape of spray tip is similar to blunt body when fuel spray is at transonic region. If spray entered the supersonic region, the oblique shock waves are induced instead of normal shock wave. With the velocity of spray increasing, the spray front angle and shock wave angle are increased. The tip region of the supersonic fuel spray is commonly formed a cone. Mean droplet diameter of fuel spray is measured using Malvern’s Spraytec. Then the mean droplet diameter results are compared with three popular empirical models (Hiroyasu’s, Varde’s and Merrigton’s model). It is found that the Merrigton’s model shows a relative good correlation between models and experimental results. Finally, exponent of injection velocity in the Merrigton’s model is fitted with experimental results. PMID:28054555

  12. Experimental investigation on the characteristics of supersonic fuel spray and configurations of induced shock waves

    NASA Astrophysics Data System (ADS)

    Wang, Yong; Yu, Yu-Song; Li, Guo-Xiu; Jia, Tao-Ming

    2017-01-01

    The macro characteristics and configurations of induced shock waves of the supersonic sprays are investigated by experimental methods. Visualization study of spray shape is carried out with the high-speed camera. The macro characteristics including spray tip penetration, velocity of spray tip and spray angle are analyzed. The configurations of shock waves are investigated by Schlieren technique. For supersonic sprays, the concept of spray front angle is presented. Effects of Mach number of spray on the spray front angle are investigated. The results show that the shape of spray tip is similar to blunt body when fuel spray is at transonic region. If spray entered the supersonic region, the oblique shock waves are induced instead of normal shock wave. With the velocity of spray increasing, the spray front angle and shock wave angle are increased. The tip region of the supersonic fuel spray is commonly formed a cone. Mean droplet diameter of fuel spray is measured using Malvern’s Spraytec. Then the mean droplet diameter results are compared with three popular empirical models (Hiroyasu’s, Varde’s and Merrigton’s model). It is found that the Merrigton’s model shows a relative good correlation between models and experimental results. Finally, exponent of injection velocity in the Merrigton’s model is fitted with experimental results.

  13. Direct experimental evidence for a multiparticle-hole ground state configuration of deformed 33Mg

    NASA Astrophysics Data System (ADS)

    Datta, Ushasi; Rahaman, A.; Aumann, T.; Beceiro-Novo, S.; Boretzky, K.; Caesar, C.; Carlson, B. V.; Catford, W. N.; Chakraborty, S.; Chartier, M.; Cortina-Gil, D.; de Angelis, G.; Diaz Fernandez, P.; Emling, H.; Ershova, O.; Fraile, L. M.; Geissel, H.; Gonzalez-Diaz, D.; Jonson, B.; Johansson, H.; Kalantar-Nayestanaki, N.; Kröll, T.; Krücken, R.; Kurcewicz, J.; Langer, C.; Le Bleis, T.; Leifels, Y.; Marganiec, J.; Münzenberg, G.; Najafi, M. A.; Nilsson, T.; Nociforo, C.; Panin, V.; Paschalis, S.; Plag, R.; Reifarth, R.; Ricciardi, V.; Rossi, D.; Scheit, H.; Scheidenberger, C.; Simon, H.; Taylor, J. T.; Togano, Y.; Typel, S.; Volkov, V.; Wagner, A.; Wamers, F.; Weick, H.; Weigand, M.; Winfield, J. S.; Yakorev, D.; Zoric, M.

    2016-09-01

    The first direct experimental evidence of a multiparticle-hole ground state configuration of the neutron-rich 33Mg isotope has been obtained via intermediate energy (400 A MeV) Coulomb dissociation measurement. The major part ˜(70 ±13 )% of the cross section is observed to populate the excited states of 32Mg after the Coulomb breakup of 33Mg. The shapes of the differential Coulomb dissociation cross sections in coincidence with different core excited states favor that the valence neutron occupies both the s1 /2 and p3 /2 orbitals. These experimental findings suggest a significant reduction and merging of s d -p f shell gaps at N ˜20 and 28. The ground state configuration of 33Mg is predominantly a combination of 32Mg(3.0 ,3.5 MeV ;2-,1-) ⨂νs1/2 , 32Mg(2.5 MeV ;2+) ⨂νp3/2 , and 32Mg(0 ;0+) ⨂νp3/2 . The experimentally obtained quantitative spectroscopic information for the valence neutron occupation of the s and p orbitals, coupled with different core states, is in agreement with Monte Carlo shell model (MCSM) calculation using 3 MeV as the shell gap at N =20 .

  14. Flow Field Analysis of a Future Launcher Configuration during Start

    NASA Astrophysics Data System (ADS)

    Bozic, O.; Otto, H.

    2005-02-01

    Within the German Future Space Launcher Technology Research Program ASTRA several reusable concepts have been investigated. Particularly one dedicated for near-term application consists of an Ariane 5-type expendable core stage and two liquid fly back boosters (LFBB). The present investigation focused on the interaction between the booster and the core stage during ascent phase. The analysis is carried out numerically by means of the DLR unstructured code TAU. The numerical results allow a compressive study of the complicate flow pattern between the boosters and the central core and address the changes on aerodynamic drag between the three configurations considered. Key words: launcher, ASTRA, LFBB, flow simulation, CFD simulation, unstructured grid

  15. Unstructured CFD Aerodynamic Analysis of a Generic UCAV Configuration

    NASA Technical Reports Server (NTRS)

    Frink, Neal T.; Tormalm, Magnus; Schmidt, Stefan

    2011-01-01

    Three independent studies from the United States (NASA), Sweden (FOI), and Australia (DSTO) are analyzed to assess the state of current unstructured-grid computational fluid dynamic tools and practices for predicting the complex static and dynamic aerodynamic and stability characteristics of a generic 53-degree swept, round-leading-edge uninhabited combat air vehicle configuration, called SACCON. NASA exercised the USM3D tetrahedral cell-centered flow solver, while FOI and DSTO applied the FOI/EDGE general-cell vertex-based solver. The authors primarily employ the Reynolds Averaged Navier-Stokes (RANS) assumption, with a limited assessment of the EDGE Detached Eddy Simulation (DES) extension, to explore sensitivities to grids and turbulence models. Correlations with experimental data are provided for force and moments, surface pressure, and off-body flow measurements. The vortical flow field over SACCON proved extremely difficult to model adequately. As a general rule, the prospect of obtaining reasonable correlations of SACCON pitching moment characteristics with the RANS formulation is not promising, even for static cases. Yet, dynamic pitch oscillation results seem to produce a promising characterization of shapes for the lift and pitching moment hysteresis curves. Future studies of this configuration should include more investigation with higher-fidelity turbulence models, such as DES.

  16. Monosaccharide-NAIM derivatives for D-, L-configurational analysis.

    PubMed

    Lin, Chunchi; Kuo, Chien-Yuan; Liao, Kuo-Shiang; Yang, Wen-Bin

    2011-01-17

    The D-, L-enantiomeric pairs of common monosaccharides (xylose, ribose, rhamnose, arabinose, fucose, glucose, mannose, galactose, N-acetylgalactosamine, glucuronic acid and galacturonic acid) were derivatized with 2,3-naphthalenediamine to form the corresponding D-, L-aldo-NAIM derivatives. A simple and facile capillary electrophoretic method was established for sugar composition analysis by simultaneously determining the migration times of these aldo-NAIMs using borate buffer at high pH (100 mM, pH 9.0). The methodology is also applicable to sialic acid (ketose monosaccharides). The quantitation level of the proposed method was in the 10~500 ppm range and the LOD was 1 ppm. The enantioseparation of D, L pairs of aldo-NAIMs were also achieved by using modified sulfated-α-cyclodextrin as the chiral selector in phosphate buffer (300 mM, pH 3.0). In addition, the combination by reductive amination of amino-aldo-NAIM agent and D-, L-enantiomeric pairs of monosaccharides formed a diastereomeric pair for saccharide configuration analysis. Aldo-NAIM derivatives are thus shown to be rapid and efficient agents for analyzing saccharide compositions and configurations with good linearity and short analysis times via capillary electrophoresis.

  17. Comparative analysis of imaging configurations and objectives for Fourier microscopy.

    PubMed

    Kurvits, Jonathan A; Jiang, Mingming; Zia, Rashid

    2015-11-01

    Fourier microscopy is becoming an increasingly important tool for the analysis of optical nanostructures and quantum emitters. However, achieving quantitative Fourier space measurements requires a thorough understanding of the impact of aberrations introduced by optical microscopes that have been optimized for conventional real-space imaging. Here we present a detailed framework for analyzing the performance of microscope objectives for several common Fourier imaging configurations. To this end, we model objectives from Nikon, Olympus, and Zeiss using parameters that were inferred from patent literature and confirmed, where possible, by physical disassembly. We then examine the aberrations most relevant to Fourier microscopy, including the alignment tolerances of apodization factors for different objective classes, the effect of magnification on the modulation transfer function, and vignetting-induced reductions of the effective numerical aperture for wide-field measurements. Based on this analysis, we identify an optimal objective class and imaging configuration for Fourier microscopy. In addition, the Zemax files for the objectives and setups used in this analysis have been made publicly available as a resource for future studies.

  18. Nonlinear potential analysis techniques for supersonic-hypersonic configuration design

    NASA Technical Reports Server (NTRS)

    Clever, W. C.; Shankar, V.

    1983-01-01

    Approximate nonlinear inviscid theoretical techniques for predicting aerodynamic characteristics and surface pressures for relatively slender vehicles at moderate hypersonic speeds were developed. Emphasis was placed on approaches that would be responsive to preliminary configuration design level of effort. Second order small disturbance and full potential theory was utilized to meet this objective. Numerical pilot codes were developed for relatively general three dimensional geometries to evaluate the capability of the approximate equations of motion considered. Results from the computations indicate good agreement with higher order solutions and experimental results for a variety of wing, body and wing-body shapes for values of the hypersonic similarity parameter M delta approaching one. Case computational times of a minute were achieved for practical aircraft arrangements.

  19. Experimental investigation on the effect of slat geometrical configurations on aerodynamic noise

    NASA Astrophysics Data System (ADS)

    Pagani, Carlos C.; Souza, Daniel S.; Medeiros, Marcello A. F.

    2017-04-01

    Relatively few studies have addressed the slat noise dependence on gap, overlap and deflection angle, although slat noise level and spectral content are topics of increasing concern in the aeronautical industry. This paper presents new experimental data on the subject. An array of microphones placed in a closed-section wind tunnel was used in the experiments. Beamforming signal processing enhanced by DAMAS (Deconvolution Approach for the Mapping of Acoustic Sources) was applied to the data. The experimental data covered a range of angles of attack and Mach numbers, for which the typical slat noise signature features high-level narrow-band peaks, broadband noise and a single broad tone. The narrow-band peaks often dominate the slat noise spectra and arise at Strouhal numbers up to approximately 5. The broadband noise is well characterized for Strouhal numbers between 5 and 20, whereas the broad tone arises for Strouhal above 20. A total of 10 different slat configurations, including variations in gap, overlap and deflection angle were tested. The slat noise dependence on gap, overlap and slat deflection angle was assessed by letting each of them vary separately. The slat configuration exerted a substantial effect on all slat noise components, with variations of up to 20 dB/Hz in the level of the narrow-band peaks. In general, the level of the narrow-band peaks reduced and the high frequency content increased as the gap, overlap, angle of attack and slat deflection increased separately or in combination. The aerodynamically optimized baseline configuration is very distinct from the lowest noise one.

  20. Experimental and theoretical study of the effects of wing geometry on a supersonic multibody configuration

    NASA Technical Reports Server (NTRS)

    Bauer, Steven X. S.; Mcmillin, S. Naomi

    1988-01-01

    An experimental and theoretical investigation of planform effects on a low-fineness ratio multibody configuration was conducted in NASA-Langley Research Center's Unitary Plan Wind Tunnel at Mach number of 1.6, 1.8, 2.0 and 2.16. Experimental and theoretical values of lift, drag, and pitching moment as well as surface pressures were obtained on several configurations which varied in both outboard-wing panel and inboard-wing panel planforms. The three outboard-wing panels were a 65 -deg delta and two trapezoidal wing planforms. An unswept and a 60-deg swept inboard-wing panels were also tested. The purpose of the study was to determine the effect of wing planform on the supersonic aerodynamics. The large trapezoidal wing provided increased performance over the small trapezoidal wing primarily due to a reduction in the zero-lift drag coefficient. The swept inboard-wing panel planforms provided a slightly higher L/D than the unswept inboard-wing panel due to a minimal improvement in zero-lift drag. Linear-theory aerodynamic codes were used to analyze the effect of planform on the supersonic aerodynamics and were found to generally produce adequate results.

  1. Configuration optimization and experimental accuracy evaluation of a bone-attached, parallel robot for skull surgery.

    PubMed

    Kobler, Jan-Philipp; Nuelle, Kathrin; Lexow, G Jakob; Rau, Thomas S; Majdani, Omid; Kahrs, Lueder A; Kotlarski, Jens; Ortmaier, Tobias

    2016-03-01

    Minimally invasive cochlear implantation is a novel surgical technique which requires highly accurate guidance of a drilling tool along a trajectory from the mastoid surface toward the basal turn of the cochlea. The authors propose a passive, reconfigurable, parallel robot which can be directly attached to bone anchors implanted in a patient's skull, avoiding the need for surgical tracking systems. Prior to clinical trials, methods are necessary to patient specifically optimize the configuration of the mechanism with respect to accuracy and stability. Furthermore, the achievable accuracy has to be determined experimentally. A comprehensive error model of the proposed mechanism is established, taking into account all relevant error sources identified in previous studies. Two optimization criteria to exploit the given task redundancy and reconfigurability of the passive robot are derived from the model. The achievable accuracy of the optimized robot configurations is first estimated with the help of a Monte Carlo simulation approach and finally evaluated in drilling experiments using synthetic temporal bone specimen. Experimental results demonstrate that the bone-attached mechanism exhibits a mean targeting accuracy of [Formula: see text] mm under realistic conditions. A systematic targeting error is observed, which indicates that accurate identification of the passive robot's kinematic parameters could further reduce deviations from planned drill trajectories. The accuracy of the proposed mechanism demonstrates its suitability for minimally invasive cochlear implantation. Future work will focus on further evaluation experiments on temporal bone specimen.

  2. Disposal criticality analysis for immobilized Pu: External configurations

    SciTech Connect

    Gottlieb, P.; Goluoglu, S.; Cloke, P.L.

    1998-03-01

    The problem of potential external criticality is defined according to the following features and issues: The environment outside the waste package is most conveniently divided into 3 zones: (1) Near-field, in the drift, external to the waste package; (2) Near far-field, several meters into the host rock immediately adjacent to the drift; (3) Far far-field, everything beyond the near far-field. These zones have different mechanisms for accumulating a critical mass from the passing waste package outflow. Fissile material can be transported outside of the waste package thereby becoming separated from the neutron absorber. Descriptions of uranium mineral deposits imply that concentrations sufficient for criticality can be accumulated by natural processes, particularly if the uranium is highly enriched. Some configurations of fissile material in the external environment have been identified as having the potential for autocatalytic criticality behavior, but without examining the likelihood of the processes necessary to achieve such configurations. The following factors limit the possibility of external criticality: absence of geologic formations in Yucca Mountain which can cause sufficient concentration, and length of time required to form the typical geologic mineral deposit. The paper summarizes the approach used to analyze criticality and gives results and conclusions of the analysis.

  3. Techno-economic analysis of biofuel production considering logistic configurations.

    PubMed

    Li, Qi; Hu, Guiping

    2016-04-01

    In the study, a techno-economic analysis method considering logistic configurations is proposed. The economic feasibility of a low temperature biomass gasification pathway and an integrated pathway with fast pyrolysis and bio-oil gasification are evaluated and compared with the proposed method in Iowa. The results show that both pathways are profitable, biomass gasification pathway could achieve an Internal Rate of Return (IRR) of 10.00% by building a single biorefinery and integrated bio-oil gasification pathway could achieve an IRR of 3.32% by applying decentralized supply chain structure. A Monte-Carlo simulation considering interactions among parameters is also proposed and conducted, which indicates that both pathways are at high risk currently. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Experimental Investigation of the DLR-F6 Transport Configuration in the National Transonic Facility

    NASA Technical Reports Server (NTRS)

    Gatlin, Gregory M.; Rivers, Melissa B.; Goodliff, Scott L.; Rudnik, Ralf; Sitzmann, Martin

    2008-01-01

    An experimental aerodynamic investigation of the DLR (German Aerospace Center) F6 generic transport configuration has been conducted in the NASA NTF (National Transonic Facility) for CFD validation within the framework of the AIAA Drag Prediction Workshop. Force and moment, surface pressure, model deformation, and surface flow visualization data have been obtained at Reynolds numbers of both 3 million and 5 million. Flow-through nacelles and a side-of-body fairing were also investigated on this wing-body configuration. Reynolds number effects on trailing edge separation have been assessed, and the effectiveness of the side-of-body fairing in eliminating a known region of separated flow has been determined. Data obtained at a Reynolds number of 3 million are presented together for comparison with data from a previous wind tunnel investigation in the ONERA S2MA facility. New surface flow visualization capabilities have also been successfully explored and demonstrated in the NTF for the high pressure and moderately low temperature conditions required in this investigation. Images detailing wing surface flow characteristics are presented.

  5. Experimental and Computational Studies of the Flow Over a Sting Mounted Planetary Probe Configuration

    NASA Technical Reports Server (NTRS)

    Holden, Michael S.; Harvey, John K.; Boyd, Iain D.; George, Jyothish; Horvath, Thomas J.

    1997-01-01

    This paper summarizes the results of a series of experimental studies in the LENS shock tunnel and computations with DSMC and Navier Stokes codes which have been made to examine the aerothermal and flowfield characteristics of the flow over a sting-supported planetary probe configuration in hypervelocity air and nitrogen flows. The experimental program was conducted in the LENS hypervelocity shock tunnel at total enthalpies of 5and 10 MJkg for a range of reservoir pressure conditions from 70 to 500 bars. Heat transfer and pressure measurements were made on the front and rear face of the probe and along the supporting sting. High-speed and single shot schlieren photography were also employed to examine the flow over the model and the time to establish the flow in the base recirculation region. Predictions of the flowfield characteristics and the distributions of heat transfer and pressure were made with DSMC codes for rarefied flow conditions and with the Navier-Stokes solvers for the higher pressure conditions where the flows were assumed to be laminar. Analysis of the time history records from the heat transfer and pressure instrumentation on the face of the probe and in the base region indicated that the base flow was fully established in under 4 milliseconds from flow initiation or between 35 and 50 flow lengths based on base height. The measurements made in three different tunnel entries with two models of identical geometries but with different instrumentation packages, one prepared by NASA Langley and the second prepared by CUBRC, demonstrated good agreement between heat transfer measurements made with two different types of thin film and coaxial gage instrumentation. The measurements of heat transfer and pressure to the front face of the probe were in good agreement with theoretical predictions from both the DSMC and Navier Stokes codes. For the measurements made in low density flows, computations with the DSMC code were found to compare well with the

  6. Experimental study of the interference resistance of pentamaran asymmetric side-hull configurations

    NASA Astrophysics Data System (ADS)

    Yanuar, Ibadurrahman, Karim, S.; Ichsan, M.

    2017-03-01

    An experimental investigation has been performed to assess the relation of interference performances on the total resistance of pentamaran model advancing in calm water. For this motive, total drag of the ship has been carried out for several values of the asymmetric side-hull positions and hull separations at changing the Froude number in the range 0.3-0.9. Our results indicate that a remarkable change of resistance require notable changes in transverse distance values (hull separation) when wave interference may take place. On top of that, there is no single configuration that constancy out-performed the others across the entire speed range, and the optimum interference factor (-0.2) appears at Froude number of 0.45 by the outriggers outer position: asymmetric outboard.

  7. Experimental configuration of direct drive cylindrical implosions on the Omega Laser

    SciTech Connect

    Barnes, C.W.; Tubbs, D.L.; Beck, J.B.

    1998-12-31

    Details about the cylindrical implosions using direct-drive irradiation on the OMEGA Laser facility are provided. The experimental configuration, including orientation, construction, and mounting of the targets is described. An attempt to characterize the modulation transfer function of the primary x-ray framing camera diagnostic results in insufficient exposure contrast but relative agreement with other determinations. The x-ray intensity of the titanium backlighter driven by the 2.5-nsec linear ramp of the laser beams is described, and the relative intensity on film is compared to similar Nova experiments. The parallax effects of different length marker layers of high-opacity dichloropolystyrene is measured, resulting in the conclusion that the marker layer length should be matched to the laser drive illumination profile.

  8. Experimental Investigation of a Point Design Optimized Arrow Wing HSCT Configuration

    NASA Technical Reports Server (NTRS)

    Narducci, Robert P.; Sundaram, P.; Agrawal, Shreekant; Cheung, S.; Arslan, A. E.; Martin, G. L.

    1999-01-01

    The M2.4-7A Arrow Wing HSCT configuration was optimized for straight and level cruise at a Mach number of 2.4 and a lift coefficient of 0.10. A quasi-Newton optimization scheme maximized the lift-to-drag ratio (by minimizing drag-to-lift) using Euler solutions from FL067 to estimate the lift and drag forces. A 1.675% wind-tunnel model of the Opt5 HSCT configuration was built to validate the design methodology. Experimental data gathered at the NASA Langley Unitary Plan Wind Tunnel (UPWT) section #2 facility verified CFL3D Euler and Navier-Stokes predictions of the Opt5 performance at the design point. In turn, CFL3D confirmed the improvement in the lift-to-drag ratio obtained during the optimization, thus validating the design procedure. A data base at off-design conditions was obtained during three wind-tunnel tests. The entry into NASA Langley UPWT section #2 obtained data at a free stream Mach number, M(sub infinity), of 2.55 as well as the design Mach number, M(sub infinity)=2.4. Data from a Mach number range of 1.8 to 2.4 was taken at UPWT section #1. Transonic and low supersonic Mach numbers, M(sub infinity)=0.6 to 1.2, was gathered at the NASA Langley 16 ft. Transonic Wind Tunnel (TWT). In addition to good agreement between CFD and experimental data, highlights from the wind-tunnel tests include a trip dot study suggesting a linear relationship between trip dot drag and Mach number, an aeroelastic study that measured the outboard wing deflection and twist, and a flap scheduling study that identifies the possibility of only one leading-edge and trailing-edge flap setting for transonic cruise and another for low supersonic acceleration.

  9. Experimental Investigation of a Point Design Optimized Arrow Wing HSCT Configuration

    NASA Technical Reports Server (NTRS)

    Narducci, Robert P.; Sundaram, P.; Agrawal, Shreekant; Cheung, S.; Arslan, A. E.; Martin, G. L.

    1999-01-01

    The M2.4-7A Arrow Wing HSCT configuration was optimized for straight and level cruise at a Mach number of 2.4 and a lift coefficient of 0.10. A quasi-Newton optimization scheme maximized the lift-to-drag ratio (by minimizing drag-to-lift) using Euler solutions from FL067 to estimate the lift and drag forces. A 1.675% wind-tunnel model of the Opt5 HSCT configuration was built to validate the design methodology. Experimental data gathered at the NASA Langley Unitary Plan Wind Tunnel (UPWT) section #2 facility verified CFL3D Euler and Navier-Stokes predictions of the Opt5 performance at the design point. In turn, CFL3D confirmed the improvement in the lift-to-drag ratio obtained during the optimization, thus validating the design procedure. A data base at off-design conditions was obtained during three wind-tunnel tests. The entry into NASA Langley UPWT section #2 obtained data at a free stream Mach number, M(sub infinity), of 2.55 as well as the design Mach number, M(sub infinity)=2.4. Data from a Mach number range of 1.8 to 2.4 was taken at UPWT section #1. Transonic and low supersonic Mach numbers, M(sub infinity)=0.6 to 1.2, was gathered at the NASA Langley 16 ft. Transonic Wind Tunnel (TWT). In addition to good agreement between CFD and experimental data, highlights from the wind-tunnel tests include a trip dot study suggesting a linear relationship between trip dot drag and Mach number, an aeroelastic study that measured the outboard wing deflection and twist, and a flap scheduling study that identifies the possibility of only one leading-edge and trailing-edge flap setting for transonic cruise and another for low supersonic acceleration.

  10. Experimental and numerical validation for the novel configuration of an arthroscopic indentation instrument

    NASA Astrophysics Data System (ADS)

    Korhonen, Rami K.; Saarakkala, Simo; Töyräs, Juha; Laasanen, Mikko S.; Kiviranta, Ilkka; Jurvelin, Jukka S.

    2003-06-01

    Softening of articular cartilage, mainly attributable to deterioration of superficial collagen network and depletion of proteoglycans, is a sign of incipient osteoarthrosis. Early diagnosis of osteoarthrosis is essential to prevent the further destruction of the tissue. During the past decade, a few arthroscopic instruments have been introduced for the measurement of cartilage stiffness; these can be used to provide a sensitive measure of cartilage status. Ease of use, accuracy and reproducibility of the measurements as well as a low risk of damaging cartilage are the main qualities needed in any clinically applicable instrument. In this study, we have modified a commercially available arthroscopic indentation instrument to better fulfil these requirements when measuring cartilage stiffness in joints with thin cartilage. Our novel configuration was validated by experimental testing as well as by finite element (FE) modelling. Experimental and numerical tests indicated that it would be better to use a smaller reference plate and a lower pressing force (3 N) than those used in the original instrument (7-10 N). The reproducibility (CV = 5.0%) of the in situ indentation measurements was improved over that of the original instrument (CV = 7.6%), and the effect of material thickness on the indentation response was smaller than that obtained with the original instrument. The novel configuration showed a significant linear correlation between the indenter force and the reference dynamic modulus of cartilage in unconfined compression, especially in soft tissue (r = 0.893, p < 0.001, n = 16). FE analyses with a transversely isotropic poroelastic model indicated that the instrument was suitable for detecting the degeneration of superficial cartilage. In summary, the instrument presented in this study allows easy and reproducible measurement of cartilage stiffness, also in thin cartilage, and therefore represents a technical improvement for the early diagnosis of

  11. Criticality Benchmark Analysis of the HTTR Annular Startup Core Configurations

    SciTech Connect

    John D. Bess

    2009-11-01

    One of the high priority benchmarking activities for corroborating the Next Generation Nuclear Plant (NGNP) Project and Very High Temperature Reactor (VHTR) Program is evaluation of Japan's existing High Temperature Engineering Test Reactor (HTTR). The HTTR is a 30 MWt engineering test reactor utilizing graphite moderation, helium coolant, and prismatic TRISO fuel. A large amount of critical reactor physics data is available for validation efforts of High Temperature Gas-cooled Reactors (HTGRs). Previous international reactor physics benchmarking activities provided a collation of mixed results that inaccurately predicted actual experimental performance.1 Reevaluations were performed by the Japanese to reduce the discrepancy between actual and computationally-determined critical configurations.2-3 Current efforts at the Idaho National Laboratory (INL) involve development of reactor physics benchmark models in conjunction with the International Reactor Physics Experiment Evaluation Project (IRPhEP) for use with verification and validation methods in the VHTR Program. Annular cores demonstrate inherent safety characteristics that are of interest in developing future HTGRs.

  12. Nonlinear Aeroelastic Analysis of Joined-Wing Configurations

    NASA Astrophysics Data System (ADS)

    Cavallaro, Rauno

    Aeroelastic design of joined-wing configurations is yet a relatively unexplored topic which poses several difficulties. Due to the overconstrained nature of the system combined with structural geometric nonlinearities, the behavior of Joined Wings is often counterintuitive and presents challenges not seen in standard layouts. In particular, instability observed on detailed aircraft models but never thoroughly investigated, is here studied with the aid of a theoretical/computational framework. Snap-type of instabilities are shown for both pure structural and aeroelastic cases. The concept of snap-divergence is introduced to clearly identify the true aeroelastic instability, as opposed to the usual aeroelastic divergence evaluated through eigenvalue approach. Multi-stable regions and isola-type of bifurcations are possible characterizations of the nonlinear response of Joined Wings, and may lead to branch-jumping phenomena well below nominal critical load condition. Within this picture, sensitivity to (unavoidable) manufacturing defects could have potential catastrophic effects. The phenomena studied in this work suggest that the design process for Joined Wings needs to be revisited and should focus, when instability is concerned, on nonlinear post-critical analysis since linear methods may provide wrong trend indications and also hide potentially catastrophical situations. Dynamic aeroelastic analyses are also performed. Flutter occurrence is critically analyzed with frequency and time-domain capabilities. Sensitivity to different-fidelity aeroelastic modeling (fluid-structure interface algorithm, aerodynamic solvers) is assessed showing that, for some configurations, wake modeling (rigid versus free) has a strong impact on the results. Post-flutter regimes are also explored. Limit cycle oscillations are observed, followed, in some cases, by flip bifurcations (period doubling) and loss of periodicity of the solution. Aeroelastic analyses are then carried out on a

  13. Multi-Body Analysis of a Tiltrotor Configuration

    NASA Technical Reports Server (NTRS)

    Ghiringhelli, G. L.; Masarati, P.; Mantegazza, P.; Nixon, M. W.

    1997-01-01

    The paper describes the aeroelastic analysis of a tiltrotor configuration. The 1/5 scale wind tunnel semispan model of the V-22 tiltrotor aircraft is considered. The analysis is performed by means of a multi-body code, based on an original formulation. The differential equilibrium problem is stated in terms of first order differential equations. The equilibrium equations of every rigid body are written, together with the definitions of the momenta. The bodies are connected by kinematic constraints, applied in form of Lagrangian multipliers. Deformable components are mainly modelled by means of beam elements, based on an original finite volume formulation. Multi-disciplinar problems can be solved by adding user-defined differential equations. In the presented analysis the equations related to the control of the swash-plate of the model are considered. Advantages of a multi-body aeroelastic code over existing comprehensive rotorcraft codes include the exact modelling of the kinematics of the hub, the detailed modelling of the flexibility of critical hub components, and the possibility to simulate steady flight conditions as well as wind-up and maneuvers. The simulations described in the paper include: 1) the analysis of the aeroelastic stability, with particular regard to the proprotor/pylon instability that is peculiar to tiltrotors, 2) the determination of the dynamic behavior of the system and of the loads due to typical maneuvers, with particular regard to the conversion from helicopter to airplane mode, and 3) the stress evaluation in critical components, such as the pitch links and the conversion downstop spring.

  14. An Experimental Study on Aerothermal Heating of the IXV Configuration During Re-Entry

    NASA Astrophysics Data System (ADS)

    Neeb, D.; Gülhan, A.; Cosson, E.; Ameziane, R.; Binetti, P.; Walloschek, T.

    2009-01-01

    In the frame of the ESA FLPP program an experimental study on the aerothermodynamic phenomena during re- entry phase of the IXV configuration has been conducted in the hypersonic wind tunnel H2K Cologne. Tests have been carried out at Mach 8.7, three different Reynolds numbers, different flap deflection and angles of attack. The model is made of a material with low thermal conductivity, in order to measure the surface temperature distribution by means of IR thermography and to avoid any lateral heat dissipation inside the structure. Using this data the heat flux rate has been determined taking into account temperature-dependent material characteristics assuming a semi infinite wall and radiative cooling to the environment. The flow topology has been analysed using Schlieren images. Depending on the combination of the flap deflection angle and angle of attack the experimental data show a significant influence of the Reynolds number on the Shock Wave - Shock Wave (SWSWI) and Shock Wave - Boundary Layer Interactions (SWBLI), flow separation and its re-attachment leading to remarkable differences in the aerothermal heating on the flap.

  15. An experimental investigation of supersonic flow past a wedge-cylinder configuration

    NASA Technical Reports Server (NTRS)

    Barnette, D. W.

    1976-01-01

    An experimental investigation of supersonic flow past double-wedge configurations was conducted. Over the range of geometries tested, it was found that, while theoretical solutions both for a Type V pattern and for a Type VI pattern could be generated for a particular flow condition (as defined by the geometry and the free-stream conditions), the weaker, Type VI pattern was observed experimentally. More rigorous flow-field solutions were developed for the flow along the wing leading-edge. Solutions were developed for the three-dimensional flow in the plane of symmetry of a swept cylinder (which represented the wing leading-edge) which was mounted on a wedge (which generated the "bow" shock wave). A numerical code was developed using integral techniques to calculate the flow in the shock layer upstream of the interaction region (i.e., near the wing root). Heat transfer rates were calculated for various free stream conditions. The present investigation was undertaken to examine the effects of crossflow on the resultant flow-field and to verify the flow model used in theoretical calculations.

  16. Global ideal magnetohydrodynamic stability analysis for the configurational space of Wendelstein 7-X

    NASA Astrophysics Data System (ADS)

    Nührenberg, Carolin

    1996-06-01

    A survey of the magnetohydrodynamic (MHD) stability properties of three-dimensional (3-D) MHD configurations representing the Wendelstein 7-X (W7-X) stellarator experiment [ G. Grieger et al., Plasma Physics and Controlled Nuclear Fusion Research, 1990 (International Atomic Energy Agency, Vienna, 1991), Vol. 3, p. 525] was performed with the Code for the Analysis for the Stability of 3-D Equilibria (CAS3D) [C. Schwab, Phys. Fluids B 5, 3195 (1993)] . This study confirms and elaborates previous indications on the structural characteristics of global MHD modes in stellarators. In particular these characteristics pertain to the compressibility of these modes, the equivalence of the decoupled stability problems for the modes with different parities, and the separability of global from fine-scale perturbations within the same mode family. As to the W7-X stellarator experiment, the envisaged configurational class—providing the intended experimental flexibility—appears to offer scenarios of safely stable operation.

  17. An experimental study of the lift, drag and static longitudinal stability for a three lifting surface configuration

    NASA Technical Reports Server (NTRS)

    Ostowari, C.; Naik, D.

    1986-01-01

    The experimental procedure and aerodynamic force and moment measurements for wind tunnel testing of the three lifting surface configuration (TLC) are described. The influence of nonelliptical lift distributions on lift, drag, and static longitudinal stability are examined; graphs of the lift coefficient versus angle of attack, the pitching moment coefficient, drag coefficient, and lift to drag ratio versus lift coefficient are provided. The TLC data are compared with the conventional tail-aft configuration and the canard-wing configuration; it is concluded that the TLC has better lift and high-lift drag characteristics, lift to drag ratio, and zero-lift moments than the other two configurations. The effects of variations in forward and tail wind incidence angles, gap, stagger, and forward wind span on the drag, lift, longitudinal stability, and zero-lift moments of the configuration are studied.

  18. Experimental Investigation of the Low-Speed Aerodynamic Characteristics of a 5.8-Percent Scale Hybrid Wing Body Configuration

    NASA Technical Reports Server (NTRS)

    Gatlin, Gregory M.; Vicroy, Dan D.; Carter, Melissa B.

    2012-01-01

    A low-speed experimental investigation has been conducted on a 5.8-percent scale Hybrid Wing Body configuration in the NASA Langley 14- by 22-Foot Subsonic Tunnel. This Hybrid Wing Body (HWB) configuration was designed with specific intention to support the NASA Environmentally Responsible Aviation (ERA) Project goals of reduced noise, emissions, and fuel burn. This HWB configuration incorporates twin, podded nacelles mounted on the vehicle upper surface between twin vertical tails. Low-speed aerodynamic characteristics were assessed through the acquisition of force and moment, surface pressure, and flow visualization data. Longitudinal and lateral-directional characteristics were investigated on this multi-component model. The effects of a drooped leading edge, longitudinal flow-through nacelle location, vertical tail shape and position, elevon deflection, and rudder deflection have been studied. The basic configuration aerodynamics, as well as the effects of these configuration variations, are presented in this paper.

  19. Unsteady loads due to propulsive lift configurations. Part D: The development of an experimental facility for the investigation of scaling effects on propulsive lift configurations

    NASA Technical Reports Server (NTRS)

    Haviland, J. K.; Herling, W. W.

    1978-01-01

    The design and construction of an experimental facility for the investigation of scaling effects in propulsive lift configurations are described. The facility was modeled after an existing full size NASA facility which consisted of a coaxial turbofan jet engine with a rectangular nozzle in a blown surface configuration. The flow field of the model facility was examined with and without a simulated wing surface in place at several locations downstream of the nozzle exit plane. Emphasis was placed on obtaining pressure measurements which were made with static probes and surface pressure ports connected via plastic tubing to condenser microphones for fluctuating measurements. Several pressure spectra were compared with those obtained from the NASA facility, and were used in a preliminary evaluation of scaling laws.

  20. Configurational salience of landmarks: an analysis of sketch maps using Space Syntax.

    PubMed

    von Stülpnagel, Rul; Frankenstein, Julia

    2015-09-01

    We conducted a visibility graph analysis (a Space Syntax method) of a virtual environment to examine how the configurational salience of global and local landmarks (i.e., their relative positions in the environment) as compared to their visual salience affects the probability of their depiction on sketch maps. Participants of two experimental conditions produced sketch maps from memory after exploration with a layout map or without a map, respectively. Participants of a third condition produced sketch maps in parallel to exploration. More detailed sketch maps were produced in the third condition, but landmarks with higher configurational salience were depicted more frequently across all experimental conditions. Whereas the inclusion of global landmarks onto sketch maps was best predicted by their size, both visual salience and isovist size (i.e., the area a landmark was visible from) predicted the frequency of depiction for local landmarks. Our findings imply that people determine the relevance of landmarks not only by their visual, but even more by their configurational salience.

  1. Experimental and numerical investigation of the turbulent wake flow of a generic space launcher configuration

    NASA Astrophysics Data System (ADS)

    Statnikov, V.; Saile, D.; Meiß, J.-H.; Henckels, A.; Meinke, M.; Gülhan, A.; Schröder, W.

    2015-06-01

    The turbulent wake of a generic space launcher at cold hypersonic freestream conditions is investigated experimentally and numerically to gain detailed insight into the intricate base flow phenomena of space vehicles at upper stages of the flight trajectory. The experiments are done at Ma∞ = 6 and ReD = 1.7 · 106 m-1 by the German Aerospace Center (DLR) and the corresponding computations are performed by the Institute of Aerodynamics Aachen using a zonal Reynolds-averaged Navier-Stokes / Large-Eddy Simulation (RANS/LES) approach. Two different aft-body geometries consisting of a blunt base and an attached cylindrical nozzle dummy are considered. It is found that the wind tunnel model support attached to the upper side of the main body has a nonnegligible impact on the wake along the whole circumference, albeit on the opposite side, the effects are minimal compared to an axisymmetric configuration. In the blunt-base case, the turbulent supersonic boundary layer undergoes a strong aftexpansion on the model shoulder leading to the formation of a confined low-pressure (p/p∞ ≈ 0.2) recirculation region. Adding a nozzle dummy causes the shear layer to reattach on the its wall at x/D ˜ 0.6 and the base pressure level to increase (p/p∞ ≈ 0.25) compared to the blunt-base case. For both configurations, the pressure fluctuations on the base wall feature dominant frequencies at SrD ≈ 0.05 and SrD ≈ 0.2-0.27, but are of small amplitudes (prms/p∞ = 0.02-0.025) compared to the main body boundary layer. For the nozzle dummy configuration, when moving downstream along the nozzle extension, the wall pressure is increasingly influenced by the reattaching shear layer and the periodic low-frequency behavior becomes less pronounced. Directly behind the reattachment point, the wall pressure reaches maximum mean and root-mean-square (rms) values of about p/p∞ = 1 and p'rms/p∞ = 0.1 and features a broadband specrms trum without distinct frequencies determined by the

  2. Experimental and Numerical Investigations on Debris Bed Coolability in a Multidimensional and Homogeneous Configuration with Volumetric Heat Source

    SciTech Connect

    Atkhen, Kresna; Berthoud, Georges

    2003-06-15

    Within the framework of severe reactor accident studies, we present experimental and numerical parametric studies on debris bed coolability. Data are provided by the SILFIDE multidimensional experimental facility at Electricite de France. The bed is composed of inductively heated steel sphere beads (diameters ranging from 2 to 7.18 mm) contained in a 50- x 60- x 10-cm vessel. Numerical computations are obtained with MC3D REPO developed by Commissariat a l'Energie Atomique.Because of heterogeneous power distribution within the bed, two definitions (mean and local) for the critical heat flux (CHF) are proposed. Even in the first case, the CHF was higher than the Lipinsky one-dimensional flux. As the power is being increased, temperature plateaus above saturation temperature are observed. An analysis is proposed, based on possible different hydrodynamic flow configurations occurring in postdryout regimes. In some experiments, some spheres were superficially molten and stacked together, but globally, the bed was still coolable.The influence of operational parameters such as bottom coolant injection, height of the water, fluidization of upper particles, and subcooled liquid injection on dryout phenomena and CHF values are also described.The MC3D-REPO calculations assuming a thermal equilibrium between the three phases gives results in accordance with experimental data.

  3. Steady and unsteady transonic small disturbance analysis of realistic aircraft configurations

    NASA Technical Reports Server (NTRS)

    Batina, John T.; Seidel, David A.; Bennett, Robert M.; Cunningham, Herbert J.; Bland, Samuel R.

    1989-01-01

    A transonic unsteady aerodynamic and aeroelastic code called CAP-TSD (Computational Aeroelasticity Program - Transonic Small Disturbance) was developed for application to realistic aircraft configurations. It permits the calculation of steady and unsteady flows about complete aircraft configurations for aeroelastic analysis of the flutter critical transonic speed range. The CAP-TSD code uses a time accurate approximate factorization algorithm for solution of the unsteady transonic small disturbance potential equation. An overview is given of the CAP-TSD code development effort along with recent algorithm modifications which are listed and discussed. Calculations are presented for several configurations including the General Dynamics 1/9th scale F-16C aircraft model to evaluate the algorithm and hence the reliability of the CAP-TSD code in general. Calculations are also presented for a flutter analysis of a 45 deg sweptback wing which agree well with the experimental data. Descriptions are presented of the CAP-TSD code and algorithm details along with results and comparisons which demonstrate the stability, accuracy, efficiency, and utility of CAP-TSD.

  4. A generalized method for the analysis of planar biaxial mechanical data using tethered testing configurations.

    PubMed

    Zhang, Will; Feng, Yuan; Lee, Chung-Hao; Billiar, Kristen L; Sacks, Michael S

    2015-06-01

    Simulation of the mechanical behavior of soft tissues is critical for many physiological and medical device applications. Accurate mechanical test data is crucial for both obtaining the form and robust parameter determination of the constitutive model. For incompressible soft tissues that are either membranes or thin sections, planar biaxial mechanical testing configurations can provide much information about the anisotropic stress-strain behavior. However, the analysis of soft biological tissue planar biaxial mechanical test data can be complicated by in-plane shear, tissue heterogeneities, and inelastic changes in specimen geometry that commonly occur during testing. These inelastic effects, without appropriate corrections, alter the stress-traction mapping and violates equilibrium so that the stress tensor is incorrectly determined. To overcome these problems, we presented an analytical method to determine the Cauchy stress tensor from the experimentally derived tractions for tethered testing configurations. We accounted for the measured testing geometry and compensate for run-time inelastic effects by enforcing equilibrium using small rigid body rotations. To evaluate the effectiveness of our method, we simulated complete planar biaxial test configurations that incorporated actual device mechanisms, specimen geometry, and heterogeneous tissue fibrous structure using a finite element (FE) model. We determined that our method corrected the errors in the equilibrium of momentum and correctly estimated the Cauchy stress tensor. We also noted that since stress is applied primarily over a subregion bounded by the tethers, an adjustment to the effective specimen dimensions is required to correct the magnitude of the stresses. Simulations of various tether placements demonstrated that typical tether placements used in the current experimental setups will produce accurate stress tensor estimates. Overall, our method provides an improved and relatively straightforward

  5. Experimental Investigation on Stirling Type Thermally Coupled Three Stage Pulse Tube Cryocoolers with 'U' Type Configuration

    NASA Astrophysics Data System (ADS)

    Badgujar, A. D.; Naik, H. B.; Atrey, M. D.

    Research on Stirling type Pulse Tube Cryocooler (PTC) is focused on achieving lower temperatures by cascading the stages or by multi-staging. Multi-staging can be done either by gas coupling or by thermal coupling of the stages. In the thermal coupling option, either a two stage cooler can pre-cool a single stage PTC to reach lower temperatures or a single stage PTC can cool a two stage PTC. In the present work, both these configurations are tested experimentally keeping the same two stage PTC. In case-1, the two stage PTC is used as a pre-cooling stage while in case-2, the single stage PTC is used as a pre-cooling stage. Length of the single stage is required and to be increased to match the two stages PTC for effective thermal coupling in case-1. The lowest temperature achieved in case-1 is 50.07 K where as in case-2 the lowest temperature achieved is 19.61 K at 17 bar charge pressure and 68 Hz frequency. The pressure drop in both the PTCs is compared to analyze the difference in performance.

  6. Experimental study of showerhead cooling on a cylinder comparing several configurations using cylindrical and shaped holes

    SciTech Connect

    Reiss, H.; Boelcs, A.

    2000-01-01

    Film cooling and heat transfer measurements on a cylinder model have been conducted using the transient thermochromic liquid crystal technique. Three showerhead cooling configurations adapted to leading edge film cooling of gas turbine blades were directly compared: classical cylindrical holes versus two types of shaped hole exits. The experiments were carried out in a free jet test facility at two different flow conditions, Mach numbers M = 0.14 and M = 0.26, yielding Reynolds numbers based on the cylinder diameter of 8.6e4 and 1.55e5, respectively, All experiments were done at a mainstream turbulence level of Tu = 7% with an integral length scale of L{sub x} = 9.1 mm (M = 0.14), or L{sub x} = 10.5 mm (M = 0.26), respectively. Foreign gas injection (CO{sub 2}) was used, yielding an engine-near density ratio of 1.6, with blowing ratios ranging from 0.6 to 1.5. Detailed experimental results are shown, including surface distributions of film cooling effectiveness and local heat transfer coefficients. Additionally, heat transfer and heat load augmentation due to injection with respect to the uncooled cylinder are reported. For a given cooling gas consumption, the laid-back shaped hole exits lead to a clear enhancement of the cooling performance compared to cylindrical exits, whereas laterally expanded holes give only slight performance enhancement.

  7. Analysis of computational modeling techniques for complete rotorcraft configurations

    NASA Astrophysics Data System (ADS)

    O'Brien, David M., Jr.

    Computational fluid dynamics (CFD) provides the helicopter designer with a powerful tool for identifying problematic aerodynamics. Through the use of CFD, design concepts can be analyzed in a virtual wind tunnel long before a physical model is ever created. Traditional CFD analysis tends to be a time consuming process, where much of the effort is spent generating a high quality computational grid. Recent increases in computing power and memory have created renewed interest in alternative grid schemes such as unstructured grids, which facilitate rapid grid generation by relaxing restrictions on grid structure. Three rotor models have been incorporated into a popular fixed-wing unstructured CFD solver to increase its capability and facilitate availability to the rotorcraft community. The benefit of unstructured grid methods is demonstrated through rapid generation of high fidelity configuration models. The simplest rotor model is the steady state actuator disk approximation. By transforming the unsteady rotor problem into a steady state one, the actuator disk can provide rapid predictions of performance parameters such as lift and drag. The actuator blade and overset blade models provide a depiction of the unsteady rotor wake, but incur a larger computational cost than the actuator disk. The actuator blade model is convenient when the unsteady aerodynamic behavior needs to be investigated, but the computational cost of the overset approach is too large. The overset or chimera method allows the blades loads to be computed from first-principles and therefore provides the most accurate prediction of the rotor wake for the models investigated. The physics of the flow fields generated by these models for rotor/fuselage interactions are explored, along with efficiencies and limitations of each method.

  8. High-Speed Research: 1994 Sonic Boom Workshop. Configuration, Design, Analysis and Testing

    NASA Technical Reports Server (NTRS)

    McCurdy, David A. (Editor)

    1999-01-01

    The third High-Speed Research Sonic Boom Workshop was held at NASA Langley Research Center on June 1-3, 1994. The purpose of this workshop was to provide a forum for Government, industry, and university participants to present and discuss progress in their research. The workshop was organized into sessions dealing with atmospheric propagation; acceptability studies; and configuration design, and testing. Attendance at the workshop was by invitation only. The workshop proceedings include papers on design, analysis, and testing of low-boom high-speed civil transport configurations and experimental techniques for measuring sonic booms. Significant progress is noted in these areas in the time since the previous workshop a year earlier. The papers include preliminary results of sonic boom wind tunnel tests conducted during 1993 and 1994 on several low-boom designs. Results of a mission performance analysis of all low-boom designs are also included. Two experimental methods for measuring near-field signatures of airplanes in flight are reported.

  9. Toward the routine aerodynamic analysis of complex configurations

    NASA Technical Reports Server (NTRS)

    Madson, Michael D.; Erickson, Larry L.

    1990-01-01

    An evaluation is made of the ability of the TranAir CFD code to routinely compute the aerodynamic characteristics of complex subsonic and supersonic aircraft configurations. TranAir solves the full-potential equation for transonic flow about completely arbitrary geometries, using the surface-paneling PanAir technique in geometry definition. The uniform global grid may be locally refined in regions where flow properties are rapidly changing, such as regions where shocks arise, and around wing leading edges. Unlike panel method codes, TranAir solutions are not undermined by small-perturbation assumptions. Illustrative results are presented for such configurations as the F-16A with wingtip-mounted missiles and underwing fuel tanks, a generic fighter configuration, and a model of NASA-Ames' 12-ft Pressure Wind Tunnel.

  10. Aerodynamic configuration design using response surface methodology analysis

    NASA Astrophysics Data System (ADS)

    Engelund, Walter C.; Stanley, Douglas O.; Lepsch, Roger A.; McMillin, Mark M.; Unal, Resit

    1993-08-01

    An investigation has been conducted to determine a set of optimal design parameters for a single-stage-to-orbit reentry vehicle. Several configuration geometry parameters which had a large impact on the entry vehicle flying characteristics were selected as design variables: the fuselage fineness ratio, the nose to body length ratio, the nose camber value, the wing planform area scale factor, and the wing location. The optimal geometry parameter values were chosen using a response surface methodology (RSM) technique which allowed for a minimum dry weight configuration design that met a set of aerodynamic performance constraints on the landing speed, and on the subsonic, supersonic, and hypersonic trim and stability levels. The RSM technique utilized, specifically the central composite design method, is presented, along with the general vehicle conceptual design process. Results are presented for an optimized configuration along with several design trade cases.

  11. Aerodynamic configuration design using response surface methodology analysis

    NASA Technical Reports Server (NTRS)

    Engelund, Walter C.; Stanley, Douglas O.; Lepsch, Roger A.; Mcmillin, Mark M.; Unal, Resit

    1993-01-01

    An investigation has been conducted to determine a set of optimal design parameters for a single-stage-to-orbit reentry vehicle. Several configuration geometry parameters which had a large impact on the entry vehicle flying characteristics were selected as design variables: the fuselage fineness ratio, the nose to body length ratio, the nose camber value, the wing planform area scale factor, and the wing location. The optimal geometry parameter values were chosen using a response surface methodology (RSM) technique which allowed for a minimum dry weight configuration design that met a set of aerodynamic performance constraints on the landing speed, and on the subsonic, supersonic, and hypersonic trim and stability levels. The RSM technique utilized, specifically the central composite design method, is presented, along with the general vehicle conceptual design process. Results are presented for an optimized configuration along with several design trade cases.

  12. Safety analysis of the MYRRHA facility with different core configurations

    SciTech Connect

    Arien, B.; Heusdains, S.; Alt Abderrahim, H.; Malambu, E.

    2006-07-01

    In the framework of the IAEA Coordinated Research Project on 'Studies of Innovative Reactor Technology Options for Effective Incineration of Radioactive Waste', a benchmark exercise was undertaken to analyse the behaviour of the MYRRHA facility in various accidental conditions. The transients were simulated by means of the RELAP and SITHER codes and the following set of accident scenarios was considered: loss of flow, loss of heat sink, overpower transient, overcooling and partial blockage of a subassembly. In addition, those accidents were simulated in two different situations depending on whether the proton beam is cut off (protected case) or not (unprotected case). In the IAEA benchmark two subcritical core configurations are considered: a typical core configuration composed only of (U-Pu)O{sub 2} MOX fuel assemblies and another one including additional U-free minor actinides fuel assemblies. The present paper summarized the main results obtained with the first core configuration. (authors)

  13. Configurational analysis of uranium-doped thorium dioxide

    NASA Astrophysics Data System (ADS)

    Shields, A. E.; Ruiz-Hernandez, S. E.; de Leeuw, N. H.

    2015-04-01

    While thorium dioxide is already used industrially in high temperature applications, more insight is needed about the behaviour of the material as part of a mixed-oxide (MOX) nuclear fuel, incorporating uranium. We have developed a new interatomic potential model, commensurate with a prominent existing UO2 potential, to conduct configurational analyses of uranium-doped ThO2 supercells. Using the GULP and Site Occupancy Disorder (SOD) computational codes, we have analysed the distribution of low concentrations of uranium in the bulk material, but have not observed the formation of uranium clusters or a single dominant configuration.

  14. Sensitivity Analysis and Optimization of Aerodynamic Configurations with Blend Surfaces

    NASA Technical Reports Server (NTRS)

    Thomas, A. M.; Tiwari, S. N.

    1997-01-01

    A novel (geometrical) parametrization procedure using solutions to a suitably chosen fourth order partial differential equation is used to define a class of airplane configurations. Inclusive in this definition are surface grids, volume grids, and grid sensitivity. The general airplane configuration has wing, fuselage, vertical tail and horizontal tail. The design variables are incorporated into the boundary conditions, and the solution is expressed as a Fourier series. The fuselage has circular cross section, and the radius is an algebraic function of four design parameters and an independent computational variable. Volume grids are obtained through an application of the Control Point Form method. A graphic interface software is developed which dynamically changes the surface of the airplane configuration with the change in input design variable. The software is made user friendly and is targeted towards the initial conceptual development of any aerodynamic configurations. Grid sensitivity with respect to surface design parameters and aerodynamic sensitivity coefficients based on potential flow is obtained using an Automatic Differentiation precompiler software tool ADIFOR. Aerodynamic shape optimization of the complete aircraft with twenty four design variables is performed. Unstructured and structured volume grids and Euler solutions are obtained with standard software to demonstrate the feasibility of the new surface definition.

  15. Preliminary analysis of several microwave landing system flare elevation configurations

    NASA Technical Reports Server (NTRS)

    Goka, T.

    1975-01-01

    Configurations of MLS Flare Elevation Systems that can be considered reasonable and practical in actual implementation are identified. Each of these are analyzed and compared with respect to (1) computational requirement, (2) required coverage, and (3) accuracy including altitude and sink-rate estimation error performance.

  16. Indoor experimental facility for airborne synthetic aperture radar (SAR) configurations - rail-SAR

    NASA Astrophysics Data System (ADS)

    Kirose, Getachew; Phelan, Brian R.; Sherbondy, Kelly D.; Ranney, Kenneth I.; Koenig, Francois; Narayanan, Ram M.

    2014-05-01

    The Army Research Laboratory (ARL) is developing an indoor experimental facility to evaluate and assess airborne synthetic-aperture-radar-(SAR)-based detection capabilities. The rail-SAR is located in a multi-use facility that also provides a base for research and development in the area of autonomous robotic navigation. Radar explosive hazard detection is one key sensordevelopment area to be investigated at this indoor facility. In particular, the mostly wooden, multi-story building houses a two (2) story housing structure and an open area built over a large sandbox. The housing structure includes reconfigurable indoor walls which enable the realization of multiple See-Through-The-Wall (STTW) scenarios. The open sandbox, on the other hand, allows for surface and buried explosive hazard scenarios. The indoor facility is not rated for true explosive hazard materials so all targets will need to be inert and contain surrogate explosive fills. In this paper we discuss the current system status and describe data collection exercises conducted using canonical targets and frequencies that may be of interest to designers of ultra-wideband (UWB) airborne, ground penetrating SAR systems. A bi-static antenna configuration will be used to investigate the effects of varying airborne SAR parameters such as depression angle, bandwidth, and integration angle, for various target types and deployment scenarios. Canonical targets data were used to evaluate overall facility capabilities and limitations. These data is analyzed and summarized for future evaluations. Finally, processing techniques for dealing with RF multi-path and RFI due to operating inside the indoor facility are described in detail. Discussion of this facility and its capabilities and limitations will provide the explosive hazard community with a great airborne platform asset for sensor to target assessment.

  17. VENUS-2 Experimental Benchmark Analysis

    SciTech Connect

    Pavlovichev, A.M.

    2001-09-28

    The VENUS critical facility is a zero power reactor located at SCK-CEN, Mol, Belgium, which for the VENUS-2 experiment utilized a mixed-oxide core with near-weapons-grade plutonium. In addition to the VENUS-2 Core, additional computational variants based on each type of fuel cycle VENUS-2 core (3.3 wt. % UO{sub 2}, 4.0 wt. % UO{sub 2}, and 2.0/2.7 wt.% MOX) were also calculated. The VENUS-2 critical configuration and cell variants have been calculated with MCU-REA, which is a continuous energy Monte Carlo code system developed at Russian Research Center ''Kurchatov Institute'' and is used extensively in the Fissile Materials Disposition Program. The calculations resulted in a k{sub eff} of 0.99652 {+-} 0.00025 and relative pin powers within 2% for UO{sub 2} pins and 3% for MOX pins of the experimental values.

  18. Extended analysis of the system of even configurations of Ta II

    NASA Astrophysics Data System (ADS)

    Stachowska, E.; Dembczyński, J.; Windholz, L.; Ruczkowski, J.; Elantkowska, M.

    2017-01-01

    We performed a parametric study of the fine (fs) and hyperfine structure (hfs) for the even parity configurations of ionized tantalum (Ta II) using improved experimental fs and hfs data for 88 levels. A multi-configuration fitting procedure was performed for 47 configurations taking into account second-order perturbation theory including the effects of closed to open shell excitations. The fs and hfs parameters were calculated. Predicted values of level energies up to 86 000cm-1 are given, as well as gJ-Landé factors, magnetic dipole and electric quadrupole hyperfine structure constants A and B, when no experimental values are available.

  19. Lacunarity analysis of atomic configurations: application to ethanol-water mixtures.

    PubMed

    Gereben, Orsolya

    2015-09-01

    Lacunarity analysis is a scale-dependent method quantifying the translational invariance in patterns. In this work it is used to characterize the distribution of several subsets of atoms in molecular systems. Binary clusters and one-component (ethanol or water) hydrogen-bonded clusters of ethanol-water mixtures with 0-100mol% ethanol content were analyzed. Molecular dynamics simulations created the configurations, and all were in good agreement with the respective experimental x-ray diffraction data. Lacunarity analysis revealed that the placement of the one-component clusters at low concentration can be described by a multifractal distribution, especially in the case of ethanol. Most of the cases these clusters are not isolated entities, but form islands in binary clusters.

  20. Lacunarity analysis of atomic configurations: Application to ethanol-water mixtures

    NASA Astrophysics Data System (ADS)

    Gereben, Orsolya

    2015-09-01

    Lacunarity analysis is a scale-dependent method quantifying the translational invariance in patterns. In this work it is used to characterize the distribution of several subsets of atoms in molecular systems. Binary clusters and one-component (ethanol or water) hydrogen-bonded clusters of ethanol-water mixtures with 0 -100 mol % ethanol content were analyzed. Molecular dynamics simulations created the configurations, and all were in good agreement with the respective experimental x-ray diffraction data. Lacunarity analysis revealed that the placement of the one-component clusters at low concentration can be described by a multifractal distribution, especially in the case of ethanol. Most of the cases these clusters are not isolated entities, but form islands in binary clusters.

  1. Configuration analysis and optimization on multipolar Galatea trap

    NASA Astrophysics Data System (ADS)

    Tong, W. M.; Tao, B. Q.; Jin, X. J.; Li, Z. W.

    2016-10-01

    Multipolar Galatea magnetic trap simulation model was established with the finite element simulation software COMSOL Multiphysics. Analyses about the magnetic section configuration show that better magnetic configuration should make more plasma stay in the weak magnetic field rather than the annular magnetic shell field. Then an optimization model was established with axial electromagnetic force, weak magnetic field area and average magnetic mirror ratio as the optimization goals and with the currents of myxines as design variables. Select appropriate weight coefficients and get optimization results by applying genetic algorithm. Results show that the superiority of the target value of typical application parameters, including the average magnetic mirror can reduce more than 5%, the weak magnetic field area can increase at least 65%, at the same time, axial electromagnetic force acting on the outer myxines can be reduced to less than 50 N. Finally, the results were proved by COMSOL Multiphysics and the results proved the optimized magnetic trap configuration with more plasma in the weak magnetic field can reduce the plasma diffusion velocity and is more conducive for the constraint of plasma.

  2. Configuration analysis and optimization on multipolar Galatea trap

    SciTech Connect

    Tong, W. M. Tao, B. Q.; Jin, X. J.; Li, Z. W.

    2016-10-15

    Multipolar Galatea magnetic trap simulation model was established with the finite element simulation software COMSOL Multiphysics. Analyses about the magnetic section configuration show that better magnetic configuration should make more plasma stay in the weak magnetic field rather than the annular magnetic shell field. Then an optimization model was established with axial electromagnetic force, weak magnetic field area and average magnetic mirror ratio as the optimization goals and with the currents of myxines as design variables. Select appropriate weight coefficients and get optimization results by applying genetic algorithm. Results show that the superiority of the target value of typical application parameters, including the average magnetic mirror can reduce more than 5%, the weak magnetic field area can increase at least 65%, at the same time, axial electromagnetic force acting on the outer myxines can be reduced to less than 50 N. Finally, the results were proved by COMSOL Multiphysics and the results proved the optimized magnetic trap configuration with more plasma in the weak magnetic field can reduce the plasma diffusion velocity and is more conducive for the constraint of plasma.

  3. Scale-4 Analysis of Pressurized Water Reactor Critical Configurations: Volume 3-Surry Unit 1 Cycle 2

    SciTech Connect

    Bowman, S.M.

    1995-01-01

    The requirements of ANSI/ANS 8.1 specify that calculational methods for away-from-reactor criticality safety analyses be validated against experimental measurements. If credit for the negative reactivity of the depleted (or spent) fuel isotopics is desired, it is necessary to benchmark computational methods against spent fuel critical configurations. This report summarizes a portion of the ongoing effort to benchmark away-from-reactor criticality analysis methods using selected critical configurations from commercial pressurized-water reactors. The analysis methodology selected for all the calculations in this report is based on the codes and data provided in the SCALE-4 code system. The isotopic densities for the spent fuel assemblies in the critical configurations were calculated using the SAS2H analytical sequence of the SCALE-4 system. The sources of data and the procedures for deriving SAS2H input parameters are described in detail. The SNIKR code module was used to extract the necessary isotopic densities from the SAS2H results and to provide the data in the format required by the SCALE criticality analysis modules. The CSASN analytical sequence in SCALE-4 was used to perform resonance processing of the cross sections. The KENO V.a module of SCALE-4 was used to calculate the effective multiplication factor (k{sub eff}) of each case. The SCALE-4 27-group burnup library containing ENDF/B-IV (actinides) and ENDF/B-V (fission products) data was used for all the calculations. This volume of the report documents the SCALE system analysis of two reactor critical configurations for Surry Unit 1 Cycle 2. This unit and cycle were chosen for a previous analysis using a different methodology because detailed isotopics from multidimensional reactor calculations were available from the Virginia Power Company. These data permitted a direct comparison of criticality calculations using the utility-calculated isotopics with those using the isotopics generated by the SCALE-4

  4. Scale-4 Analysis of Pressurized Water Reactor Critical Configurations: Volume 2-Sequoyah Unit 2 Cycle 3

    SciTech Connect

    Bowman, S.M.

    1995-01-01

    The requirements of ANSI/ANS 8.1 specify that calculational methods for away-from-reactor criticality safety analyses be validated against experimental measurements. If credit for the negative reactivity of the depleted (or spent) fuel isotopics is desired, it is necessary to benchmark computational methods against spent fuel critical configurations. This report summarizes a portion of the ongoing effort to benchmark away-from-reactor criticality analysis methods using critical configurations from commercial pressurized-water reactors. The analysis methodology selected for all the calculations reported herein is based on the codes and data provided in the SCALE-4 code system. The isotopic densities for the spent fuel assemblies in the critical configurations were calculated using the SAS2H analytical sequence of the SCALE-4 system. The sources of data and the procedures for deriving SAS2H input parameters are described in detail. The SNIKR code module was used to extract the necessary isotopic densities from the SAS2H results and provide the data in the format required by the SCALE criticality analysis modules. The CSASN analytical sequence in SCALE-4 was used to perform resonance processing of the cross sections. The KENO V.a module of SCALE-4 was used to calculate the effective multiplication factor (k{sub eff}) of each case. The SCALE-4 27-group burnup library containing ENDF/B-IV (actinides) and ENDF/B-V (fission products) data was used for all the calculations. This volume of the report documents the SCALE system analysis of three reactor critical configurations for the Sequoyah Unit 2 Cycle 3. This unit and cycle were chosen because of the relevance in spent fuel benchmark applications: (1) the unit had a significantly long downtime of 2.7 years during the middle of cycle (MOC) 3, and (2) the core consisted entirely of burned fuel at the MOC restart. The first benchmark critical calculation was the MOC restart at hot, full-power (HFP) critical conditions. The

  5. StarBooster Demonstrator Cluster Configuration Analysis/Verification Program

    NASA Technical Reports Server (NTRS)

    DeTurris, Dianne J.

    2003-01-01

    In order to study the flight dynamics of the cluster configuration of two first stage boosters and upper-stage, flight-testing of subsonic sub-scale models has been undertaken using two glideback boosters launched on a center upper-stage. Three high power rockets clustered together were built and flown to demonstrate vertical launch, separation and horizontal recovery of the boosters. Although the boosters fly to conventional aircraft landing, the centerstage comes down separately under its own parachute. The goal of the project has been to collect data during separation and flight for comparison with a six degree of freedom simulation. The configuration for the delta wing canard boosters comes from a design by Starcraft Boosters, Inc. The subscale rockets were constructed of foam covered in carbon or fiberglass and were launched with commercially available solid rocket motors. The first set of boosters built were 3-ft tall with a 4-ft tall centerstage, and two additional sets of boosters were made that were each over 5-ft tall with a 7.5 ft centerstage. The rocket cluster is launched vertically, then after motor bum out the boosters are separated and flown to a horizontal landing under radio-control. An on-board data acquisition system recorded data during both the launch and glide phases of flight.

  6. Experimental evaluation of sound produced by two cylinders in a cross flow in various configurations

    NASA Astrophysics Data System (ADS)

    Bilka, Michael; Kerrian, Peter; Morris, Scott

    2012-11-01

    Cylinders in a cross flow is a canonical test case that is considered representative of industrial fluid flow problems, such as heat exchangers and aircraft landing gear. The general configurations are cylinders in tandem, parallel or staggered, which lead to several interesting flow phenomena such as wake cavity/wake interaction effects (tandem), symmetric/asymmetric wake behavior (parallel) or wake interaction/coanda effects (staggered), depending on relative location of the cylinders. In many cases, it is important to not only understand the flow interaction between the cylinders but also the acoustic consequence of such configurations. However, information on the acoustical behavior based on these configurations is relatively small compared to that of the steady aerodynamic and flow interaction behavior. The present work investigates the acoustic spectral properties of these configurations in order to characterize the sound produced by cylinder proximity and wake effects. The spectra are measured using an acoustic beam-forming technique to identify the sources and remove spurious content from the spectra.

  7. Conformation, optical properties, and absolute configuration of 2‧,3‧-isopropylideneadenosines: Theoretical vs. experimental study

    NASA Astrophysics Data System (ADS)

    Ivanova, Bojidarka; Spiteller, Michael

    2011-10-01

    The conformational analysis, determination of absolute configurations (ACs) as well as elucidation of the electronic absorption and CD spectra of chiral molecules 2',3'-O-isopropylideneadenosine ( 1), 5'-carboxy-2',3'-O-isopropylidene-D-adenosine ( 2), 2-chloro-2',3'-O-isopropylideneadenosine-5'-N- ethylcarboxamide ( 3) and 1-[6-(6-Amino-2-methyl-purin-9-yl)-2,2-dimethyl-tetrahydro-furo[3,4-d][1,3]dioxol-4-ylmethyl]-3-carbamoyl-pyridinium chloride ( 4), 9-(6-aminomethyl-2,2-dimethyl-tetrahydro-furo[3,4-d][1,3]dioxol-4-yl)-9H-purin-6-ylamine ( 5) and acetic acid 6-(6-amino-purin-9-yl)-2,2-dimethyl-tetrahydro-furo[3,4-d][1,3]dioxol-4-ylmethyl ester ( 6) are performer. The methods such as electronic absorption (EAs), diffuse reflectance (DSs) spectroscopy as well as electronic circular dichroism (ECD) are applied. The theoretical density functional theory (DFT) calculations are carried out to evaluate the optical phenomena of isolated molecules as well as dimeric associates. We are demonstrated the significance and the advances of the stereo chemical experimental and theoretical characterization of natural products and their functional synthetic derivatives, vitha a view to further elucidation of unknown extracts of same chemical class. Special attention is devoted to the role of intermolecular interactions in condense phases on the theoretical and experimental optical properties, studying the corresponding dimeric associates. These results are a key in the drug discovery, and structure-based design of functionalized nucleosides. The methods as single crystal X-ray diffraction and MALDI Orbitrap mass spectrometric imaging (MALDI Orbitrap MSI) are also applied.

  8. Configuration analysis of three chiral polypyridines functionalized with pinene groups

    NASA Astrophysics Data System (ADS)

    Zhang, Xiao-Peng; Qi, Xiao-Wei; Zhang, Da-Shuai; Zhu, Lin-Hua; Wang, Xiang-Hui; Shi, Zai-Feng; Lin, Qiang

    2017-08-01

    Three polypyridines functionalized with pinene groups, (-)-'dipineno'-[4,5:4″,5″]-fused 2,2‧:6‧,2″-terpyridine ((-)-1), (-)-1,3-di-(2-(4,5-pinene)pyridyl)benzene ((-)-2) and (-)-4,5-pinene-6‧-phenyl-2,2‧-bipyridine ((-)-3) were synthesized, and their structures were characterized by single crystal X-ray diffraction and electronic circular dichroism (ECD) spectra. Although a small difference is exhibited for their molecular structures, a twisting configuration is observed for (-)-2 with a larger dihedral angle between aromatic planes relative to (-)-1 and (-)-3. Correspondingly, compound (-)-2 exhibits a shorter wavelength of low-energy absorption due to a lower planarity, while all compounds (-)-1, (-)-2 and (-)-3 show similar Cotton effects of ECD spectra.

  9. The key technique analysis and function configuration of MPLS OAM

    NASA Astrophysics Data System (ADS)

    Feng, Xiancheng; Hu, Zhonggong; Chen, Ying

    2009-08-01

    OAM function is very important to telecommunication network. Especially to the networks that need to supply QoS, OAM could simplify network operation, check network performance and decrease network operation cost. As the important and extensible carrier technology of next generation network, OAM enables that MPLS could supply multiple services capability with QoS. In this paper, MPLS OAM technique theory and protection are introduced at first. In the introduction, 1:1 protection and 1:1 protection are analyzed; Then, the MPLS OAM key technique is analyzed; At last, it configures the MPLS OAM protection and checks static LSP connection in detail. So, MPLS OAM will be very important to telecommunication of IP-packeted network.

  10. Spaceborne Doppler Precipitation Radar: System Configurations and Performance Analysis

    NASA Technical Reports Server (NTRS)

    Tanelli, Simone; Im, Eastwood

    2004-01-01

    Knowledge of the global distribution of the vertical velocity of precipitation is important in in the study of energy transportation in the atmosphere, the climate and weather. Such knowledge can only be directly acquired with the use of spaceborne Doppler precipitation radars. Although the high relative speed of the radar with respect to the rainfall particles introduces significant broadening in the Doppler spectrum, recent studies have shown that the average vertical velocity can be measured to acceptable accuracy levels by appropriate selection of radar parameters. Furthermore, methods to correct for specific errors arising from NUBF effects and pointing uncertainties have recently been developed. In this paper we will present the results of the trade studies on the performances of a spaceborne Doppler radar with different system parameters configurations.

  11. Multirole cargo aircraft options and configurations. [economic analysis

    NASA Technical Reports Server (NTRS)

    Conner, D. W.; Vaughan, J. C., III

    1979-01-01

    A future requirements and advanced market evaluation study indicates derivatives of current wide-body aircraft, using 1980 advanced technology, would be economically attractive through 2008, but new dedicated airfreighters incorporating 1990 technology, would offer little or no economic incentive. They would be economically attractive for all payload sizes, however, if RD and T costs could be shared in a joint civil/military arrangement. For the 1994-2008 cargo market, option studies indicate Mach 0.7 propfans would be economically attractive in trip cost, aircraft price and airline ROI. Spanloaders would have an even lower price and higher ROI but would have a relatively high trip cost because of aerodynamic inefficiencies. Dedicated airfreighters using propfans at Mach 0.8 cruise, laminar flow control, or cryofuels, would not provide any great economic benefits. Air cushion landing gear configurations are identified as an option for avoiding runway constraints on airport requirements and/or operational constraints are noted.

  12. Comparative analysis of different configurations of PLC-based safety systems from reliability point of view

    NASA Technical Reports Server (NTRS)

    Tapia, Moiez A.

    1993-01-01

    The study of a comparative analysis of distinct multiplex and fault-tolerant configurations for a PLC-based safety system from a reliability point of view is presented. It considers simplex, duplex and fault-tolerant triple redundancy configurations. The standby unit in case of a duplex configuration has a failure rate which is k times the failure rate of the standby unit, the value of k varying from 0 to 1. For distinct values of MTTR and MTTF of the main unit, MTBF and availability for these configurations are calculated. The effect of duplexing only the PLC module or only the sensors and the actuators module, on the MTBF of the configuration, is also presented. The results are summarized and merits and demerits of various configurations under distinct environments are discussed.

  13. Self-interstitial configurations in hcp Zr: a first principles analysis

    SciTech Connect

    Samolyuk, German D; Golubov, Stanislav I; Osetskiy, Yury N; Stoller, Roger E

    2013-01-01

    Analysis of microstructure evolution in irradiated Zr and Zr alloys based on the modern radiation damage theory suggests some important features of self-interstitial atoms (SIAs). Alignment of vacancy loops and voids along basal planes requires anisotropic interstitial transport with a dominant contribution along the basal plane. Under neutron irradiation this can be explained by one-dimensional mobility of SIA clusters but experiments under electron irradiation indicate unambiguously that even the single SIA should exhibit anisotropic diffusion. No experimental information is available on SIA properties in Zr and the data obtained by ab initio calculations within the last decade reported stable SIA configurations that should provide essentially three-dimensional diffusion. To clarify this issue, an extensive investigation of SIAs in Zr has been performed from first principles using two different codes. It was demonstrated that simulation cell size, type of pseudopotential, the exchange-correlation functional, and the c/a ratio are crucially important for determining the properties of interstitials in hcp Zr. The most stable SIA configurations lie in the basal plane, which should lead to SIA diffusion mainly along basal planes. The results provide a confirmation of basic mechanisms for microstructural evolution under irradiation.

  14. Design and analysis of air acoustic vector-sensor configurations for two-dimensional geometry.

    PubMed

    Wajid, Mohd; Kumar, Arun; Bahl, Rajendar

    2016-05-01

    Acoustic vector-sensors (AVS) have been designed using the P-P method for different microphone configurations. These configurations have been used to project the acoustic intensity on the orthogonal axes through which the direction of arrival (DoA) of a sound source has been estimated. The analytical expressions for the DoA for different microphone configurations have been derived for two-dimensional geometry. Finite element method simulation using COMSOL-Multiphysics has been performed, where the microphone signals for AVS configurations have been recorded in free field conditions. The performance of all the configurations has been evaluated with respect to angular error and root-mean-square angular error. The simulation results obtained with ideal geometry for different configurations have been corroborated experimentally with prototype AVS realizations and also compared with microphone-array method, viz., Multiple Signal Classification and Generalized Cross Correlation. Experiments have been performed in an anechoic room using different prototype AVS configurations made from small size microphones. The DoA performance using analytical expressions, simulation studies, and experiments with prototype AVS in anechoic chamber are presented in the paper. The square and delta configurations are found to perform better in the absence and presence of noise, respectively.

  15. Experimental Data for Two Different Alternator Configurations in a Solar Brayton Power System

    NASA Technical Reports Server (NTRS)

    Mason, Lee S.; Shaltens, Richard K.; Espinosa, William D.

    1997-01-01

    A solar dynamic (SD) space power system has been under test at the NASA Lewis Research Center since 1994. The SD Ground Test Demonstration (GTD) system includes a solar concentrator, heat receiver with thermal energy storage, Brayton power conversion unit, and radiator installed in a thermal-vacuum chamber with a solar simulator. The Brayton unit has been operated with two different turboalternator compressor (TAC) assemblies, one which included a Rice Lundell alternator and another which incorporated a permanent magnet (PM) alternator. The Rice alternator was part of the mini-Brayton rotating unit, designed and built during the 1970's and refurbished for the GTD. The PM TAC was a development unit from the Joint US/Russian SD Flight Project. This paper highlights the operational differences (and similarities) between the Rice and PM TAC configurations including a comparative evaluation of startup characteristics and operating performance. The two alternator configurations were tested under similar thermal conditions, as an interchangeable component within the SD system. The electrical characteristics of the two units, however, dictated the use of significantly different power conditioning and control strategies. The electrical control architectures are described and compared. Test data are presented on TAC startup and system operating performance for both configurations.

  16. Lunar lander configuration study and parametric performance analysis

    NASA Astrophysics Data System (ADS)

    Donahue, Benjamin B.; Fowler, C. R.

    1993-06-01

    Future Lunar exploration plans will call for delivery of significant mounts or cargo to provide for crew habitation, surface tansportation, and scientific exploration activities. Minimization of costly surface based infrastructure is in large part directly related to the design of the cargo delivery/landing craft. This study focused on evaluating Lunar lander concepts from a logistics oriented perspective, and outlines the approach used in the development of a preferred configuration, sets forth the benefits derived from its utilization and describes the missions and system considered. Results indicate that only direct-to-surface downloading of payloads provides for unassisted cargo removal operations imperative to efficient and low risk site buildup, including the emplacement of Space Station derivative surface habitat modules, immediate cargo jettison for both descent abort and emergency surface ascent essential to piloted missions carrying cargo, and short habitat egress/ingress paths necessary to productive surface work tours for crew members carrying hand held experiments, tools and other bulky articles. Accommodating cargo in a position underneath the vehicles structural frame, landing craft described herein eliminate altogether the necessity for dedicated surface based off-loading vehicles, the operations and maintenance associated with their operation, and the precipitous ladder climbs to and from the surface that are inherent to traditional designs. Parametric evaluations illustrate performance and mass variation with respect to mission requirements.

  17. Lunar lander configuration study and parametric performance analysis

    NASA Technical Reports Server (NTRS)

    Donahue, Benjamin B.; Fowler, C. R.

    1993-01-01

    Future Lunar exploration plans will call for delivery of significant mounts or cargo to provide for crew habitation, surface tansportation, and scientific exploration activities. Minimization of costly surface based infrastructure is in large part directly related to the design of the cargo delivery/landing craft. This study focused on evaluating Lunar lander concepts from a logistics oriented perspective, and outlines the approach used in the development of a preferred configuration, sets forth the benefits derived from its utilization and describes the missions and system considered. Results indicate that only direct-to-surface downloading of payloads provides for unassisted cargo removal operations imperative to efficient and low risk site buildup, including the emplacement of Space Station derivative surface habitat modules, immediate cargo jettison for both descent abort and emergency surface ascent essential to piloted missions carrying cargo, and short habitat egress/ingress paths necessary to productive surface work tours for crew members carrying hand held experiments, tools and other bulky articles. Accommodating cargo in a position underneath the vehicles structural frame, landing craft described herein eliminate altogether the necessity for dedicated surface based off-loading vehicles, the operations and maintenance associated with their operation, and the precipitous ladder climbs to and from the surface that are inherent to traditional designs. Parametric evaluations illustrate performance and mass variation with respect to mission requirements.

  18. Scale-4 Analysis of Pressurized Water Reactor Critical Configurations: Volume 1-Summary

    SciTech Connect

    DeHart, M.D.

    1995-01-01

    The requirements of ANSI/ANS 8.1 specify that calculational methods for away-from-reactor criticality safety analyses be validated against experimental measurements. If credit is to be taken for the reduced reactivity of burned or spent fuel relative to its original ''fresh'' composition, it is necessary to benchmark computational methods used in determining such reactivity worth against spent fuel reactivity measurements. This report summarizes a portion of the ongoing effort to benchmark away-from-reactor criticality analysis methods using critical configurations from commercial pressurized- water reactors (PWR). The analysis methodology utilized for all calculations in this report is based on the modules and data associated with the SCALE-4 code system. Isotopic densities for spent fuel assemblies in the core were calculated using the SAS2H analytical sequence in SCALE-4. The sources of data and the procedures for deriving SAS2H input parameters are described in detail. The SNIKR code sequence was used to extract the necessary isotopic densities from SAS2H results and to provide the data in the format required for SCALE-4 criticality analysis modules. The CSASN analytical sequence in SCALE-4 was used to perform resonance processing of cross sections. The KENO V.a module of SCALE-4 was used to calculate the effective multiplication factor (k{sub eff}) for the critical configuration. The SCALE-4 27-group burnup library containing ENDF/B-IV (actinides) and ENDF/B-V (fission products) data was used for analysis of each critical configuration. Each of the five volumes comprising this report provides an overview of the methodology applied. Subsequent volumes also describe in detail the approach taken in performing criticality calculations for these PWR configurations: Volume 2 describes criticality calculations for the Tennessee Valley Authority's Sequoyah Unit 2 reactor for Cycle 3; Volume 3 documents the analysis of Virginia Power's Surry Unit 1 reactor for the

  19. Revised Analysis and Configuration Interaction in Mo VI

    NASA Astrophysics Data System (ADS)

    Reader, Joseph

    2007-06-01

    Mo vi, with ground term 4p^64d ^2D, has a simple one-electron spectrum 4p^6nl-4p^6n^'l^' as well as a more complex spectrum arising from inner-shell excitations 4p^54d^2 and^ 4p^54d5s. A few years ago we observed the spectrum of Mo vi from 200 to 5300 å with a sliding-spark and the 10.7-m normal- and grazing-incidence spectrographs at NIST. We revised a number of the known even levels of the one-electron spectrum [1] and confirmed the ionization limit [1],^ which was based largely on the Penning discharge observations of Romanov and Striganov [2]. A number of Romanov and Striganov's line identifications were also revised. Our results have not yet been published. More recently, we revisited the 4p^6(4d+5s)-4p^5(4d^2+4d5s) transitions and revised several of the core-excited levels [3]. Some levels of 4p^54d^2 are highly mixed with one-electron levels, resulting in transitions at longer wavelengths between 4p^54d^2 and one-electron levels. This provides accurate connections between the ground term and some highly-excited levels and thus highly accurate Ritz-type wavelength predictions for resonance transitions. Improved values have been obtained for all of the energy levels and a new least-squares fit for the odd configurations carried out. [1] B. Edl'en, et al., Phys. Scr. 32, 215 (1985). [2] N. P. Romanov and A. R. Striganov, Opt. Spectrosc. (USSR) 27, 8 (1969). [3] A. Kancerevicius et al., Lith. Phys. J. 31,143 (1991). Supported by Office of Fusion Energy Sciences of D.O.E.

  20. Finite Element Method of Stress Analysis of Nonaxisymmetric Configurations

    DTIC Science & Technology

    1980-04-01

    30 Axisymmetric Perfectly Plastic Problem 30 Nonaxisymmetric Perfectly Plastic Problems 30 Hardening Cases, Nearly Elastic Examples 31 VI...NUMERICAL RESULTS OF ELASTIC-PLASTIC ANALYSIS Axisymmetric Perfectly Plastic Problem The first test of the elastic-plastic numerical analysis is...Nonaxisymmetric Perfectly Plastic Problems In doing the numerical solution in the axisymmetric example two segments were used in the 0 direction

  1. Transonic pressure measurements and comparison of theory to experiment for an arrow-wing configuration. Volume 1: Experimental data report, base configuration and effects of wing twist and leading-edge configuration. [wind tunnel tests, aircraft models

    NASA Technical Reports Server (NTRS)

    Manro, M. E.; Manning, K. J. R.; Hallstaff, T. H.; Rogers, J. T.

    1975-01-01

    A wind tunnel test of an arrow-wing-body configuration consisting of flat and twisted wings, as well as a variety of leading- and trailing-edge control surface deflections, was conducted at Mach numbers from 0.4 to 1.1 to provide an experimental pressure data base for comparison with theoretical methods. Theory-to-experiment comparisons of detailed pressure distributions were made using current state-of-the-art attached and separated flow methods. The purpose of these comparisons was to delineate conditions under which these theories are valid for both flat and twisted wings and to explore the use of empirical methods to correct the theoretical methods where theory is deficient.

  2. Experimental investigation of wing fin configurations for alleviation of vortex wakes of aircraft

    NASA Technical Reports Server (NTRS)

    Rossow, V. J.

    1978-01-01

    A variety of fin configurations were tested on a model of the Boeing B747 in 40 by 80 foot wind tunnels. The test results confirmed that a reduction in wake rolling moment was brought about by the vortex shed by the fins so that a wide range of designs can be used to achieve wake alleviation. It was also found that the reduction in wake-induced rolling moments was especially sensitive to the location of the smaller fins on the wing and that the penalties in lift and drag can probably be made negligible by proper fin design.

  3. Optimization of the circuit configuration of a pulsatile ECLs: an in vivo experimental study.

    PubMed

    Lim, Choon Hak; Son, Ho Sung; Lee, Jung Joo; Fang, Yong Hu; Moon, Ki Chul; Ahn, Chi Bum; Kim, Kyung Hyun; Lee, Hye Won; Sun, Kyung

    2005-01-01

    An extracorporeal life support system (ECLS) with a conventional membrane oxygenator requires a driving force for the blood to pass through hollow fiber membranes. We hypothesized that if a gravity-flow hollow fiber membrane oxygenator is installed in the circuit, the twin blood sacs of a pulsatile ECLS (the Twin-Pulse Life Support, T-PLS) can be placed downstream of the membrane oxygenator. This would increase pump output by doubling pulse rate at a given pumpsetting rate while maintaining effective pulsatility. The purpose of this study was to determine the optimal circuit configuration for T-PLS with respect to energy and pump output. Animals were randomly assigned to 2 groups in a total cardiopulmonary bypass model. In the serial group, a conventional membrane oxygenator was located between the twin blood sacs of the T-PLS. In the parallel group, the twin blood sacs were placed downstream of the gravity-flow membrane oxygenator. Energy equivalent pressure (EEP), surplus hemodynamic energy (SHE) and pump output were collected at the different pump-setting rates of 30, 40, and 50 beats per minute (BPM). At a given pump-setting rate the pulse rate doubled in the parallel group. Percent changes of mean arterial pressure to EEP were 13.0 +/- 1.7, 12.0 +/- 1.9, and 7.6 +/- 0.9% in the parallel group, while 22.5 +/- 2.4, 23.2 +/- 1.9, and 21.8 +/- 1.4 in the serial group at 30, 40, and 50 BPM of pump-setting rates. SHE at each pump setting rate was 20,131 +/- 1408, 21,739 +/- 2470, and 15,048 +/- 2108 erg/ cm3 in the parallel group, while 33,968 +/- 3001, 38,232 +/- 3281, 37,964 +/- 2693 erg/cm3 in the serial group. Pump output was higher in the parallel circuit at 40, and 50 BPM pump-setting rates (3.1 +/- 0.2, 3.7 +/- 0.2 L/min vs. 2.2 +/- 0.1 and 2.5 +/- 0.1 L/min, respectively, p =0.01). Either parallel or serial circuit configuration of T-PLS generates effective pulsatility. As for the pump out, the parallel circuit configuration provides higher flow than the

  4. Configuration analysis: an energy and first cost analysis of a large office building

    SciTech Connect

    Mangnusson, M.

    1983-01-01

    In response to the need to minimize energy use in the new Social Security Administration, Northeast Program Service Center (SSA/NEPSC), now under construction in Jamaica, Queens, New York an analysis of building configuration was undertaken. The one million square foot SSA/NEPSC federal office building was originally designed for a competition won by the joint venture firms of The Gruzen Partnership and The Ehrenkrantz Group, architects and planners, and Syska and Hennessy, mechanical and electrical engineers. When completed, the building will have 3600 employees within a 900,000 GSF, eleven story structure that will form the centerpiece of the Jamaica, Queens revitalization plan. Although substantially redesigned from the competition, two important requirements for the final building design remained: low construction cost ($70/SF-1981, New York) and low yearly energy use (45,000 /SF/YR). The strict construction cost limitations necessitated extensive value engineering of the major building systems. including the configuration.

  5. Experimental investigation of the natural divertor configuration in Heliotron-E

    SciTech Connect

    Hillis, D.L.; Mioduszewski, P.K.; Fowler, R.H.; Rome, J.A.; Motojima, O.; Mizuuchi, T.; Noda, N.; Mutoh, T.; Zushi, H.; Takahashi, R.; Obiki, T.; Iiyoshi, A.; Uo, K.

    1988-01-01

    Particle control with pump limiters and divertors has been successfully demonstrated in a number of present-day tokamaks. In a heliotron/stellarator configuration, plasma flows to the wall in distinct flux bundles, often called ''divertor stripes''. This complicated three-dimensional characteristic of the plasma edge presents a new challenge for active particle control systems such as pump limiters and divertors. The experiment described here has obtained data with an instrumented pump particle collector that is located in the ''natural'' magnetic divertor stripe of Heliotron-E. The particle collector consists of a moveable graphite assembly with single-sided particle collection and active pumping. By scanning the particle collector assembly through the plasma edge of Heliotron-E, the divertor stripe is observed to be about 2-3 cm (FWHM) in width, and pressure rises of 0.01-0.01 mTorr are observed in the particle collector pumping chamber. These measurements have demonstrated that particles leaving the bulk plasma via the divertor stripes can be collected and provide a basis for developing a divertor scheme for particle control in helical systems. Modelling of the Heliotron-E magnetic configuration at the plasma edge is used to determine the collection efficiency of the particle collector in the divertor stripes. The modeling is further extended to describe a helical divertor concept. 18 refs., 6 figs.

  6. Chiral Molecular Science: How were the absolute configurations of chiral molecules determined? "Experimental results and theories".

    PubMed

    Harada, Nobuyuki

    2017-10-05

    Molecular chirality is a key concept in chemistry, bioscience, and molecular technology, like the invention of a light-powered chiral molecular motor explained in this review. Thus, the primary research subject is how to determine the absolute configuration (AC) of chiral compounds. This review article focuses on the principle, theory, and practice of the nonempirical methods for determining ACs of chiral compounds, i.e., the Bijvoet method in X-ray crystallography and the circular dichroism (CD) exciton chirality method, together with the historical aspects of AC determination. The theoretical equations of X-ray crystallography and exciton CD spectroscopy are explained in detail, and these equations are useful for readers to understand the principle and mechanism of these methods. This review also focuses on the relative methods, where the internal reference with known AC is used and the relative configuration is determined by X-ray crystallography and/or (1) H nuclear magnetic resonance (NMR) diamagnetic anisotropy method. In these cases, CSDP acid and MαNP acid are useful for the chiral resolution of racemic alcohols, where their diastereomeric esters are easily separable by high-performance liquid chromatography (HPLC) on silica gel. Thus, these methods are useful for the preparation of enantiopure compounds and simultaneous determination of their ACs. In this review article, the above methods are explained mainly based on the author's own research results. © 2017 Wiley Periodicals, Inc.

  7. Stability Analysis of the Slowed-Rotor Compound Helicopter Configuration

    NASA Technical Reports Server (NTRS)

    Floros, Matthew W.; Johnson, Wayne

    2007-01-01

    The stability and control of rotors at high advance ratio are considered. Teetering, articulated, gimbaled, and rigid hub types are considered for a compound helicopter (rotor and fixed wing). Stability predictions obtained using an analytical rigid flapping blade analysis, a rigid blade CAMRAD II model, and an elastic blade CAMRAD II model are compared. For the flapping blade analysis, the teetering rotor is the most stable, showing no instabilities up to an advance ratio of 3 and a Lock number of 18. A notional elastic blade model of a teetering rotor is unstable at an advance ratio of 1.5, independent of pitch frequency. Analysis of the trim controls and blade flapping shows that for small positive collective pitch, trim can be maintained without excessive control input or flapping angles.

  8. Stability Analysis of the Slowed-Rotor Compound Helicopter Configuration

    NASA Technical Reports Server (NTRS)

    Johnson, Wayne; Floros, Matthew W.

    2004-01-01

    The stability and control of rotors at high advance ratio are considered. Teetering, articulated, gimbaled, and rigid hub types are considered for a compound helicopter (rotor and fixed wing). Stability predictions obtained using an analytical rigid flapping blade analysis, a rigid blade CAMRAD II model, and an elastic blade CAMRAD II model are compared. For the flapping blade analysis, the teetering rotor is the most stable, 5howing no instabilities up to an advance ratio of 3 and a Lock number of 18. With an elastic blade model, the teetering rotor is unstable at an advance ratio of 1.5. Analysis of the trim controls and blade flapping shows that for small positive collective pitch, trim can be maintained without excessive control input or flapping angles.

  9. Systems design analysis applied to launch vehicle configuration

    NASA Astrophysics Data System (ADS)

    Ryan, R.; Verderaime, V.

    1993-01-01

    As emphasis shifts from optimum-performance aerospace systems to least lift-cycle costs, systems designs must seek, adapt, and innovate cost improvement techniques in design through operations. The systems design process of concept, definition, and design was assessed for the types and flow of total quality management techniques that may be applicable in a launch vehicle systems design analysis. Techniques discussed are task ordering, quality leverage, concurrent engineering, Pareto's principle, robustness, quality function deployment, criteria, and others. These cost oriented techniques are as applicable to aerospace systems design analysis as to any large commercial system.

  10. Systems design analysis applied to launch vehicle configuration

    NASA Technical Reports Server (NTRS)

    Ryan, R.; Verderaime, V.

    1993-01-01

    As emphasis shifts from optimum-performance aerospace systems to least lift-cycle costs, systems designs must seek, adapt, and innovate cost improvement techniques in design through operations. The systems design process of concept, definition, and design was assessed for the types and flow of total quality management techniques that may be applicable in a launch vehicle systems design analysis. Techniques discussed are task ordering, quality leverage, concurrent engineering, Pareto's principle, robustness, quality function deployment, criteria, and others. These cost oriented techniques are as applicable to aerospace systems design analysis as to any large commercial system.

  11. Experimental investigation of the aerodynamic effects of distributed spanwise blowing on a fighter configuration

    NASA Technical Reports Server (NTRS)

    Huffman, J. K.; Hahne, D. E.; Johnson, T. D., Jr.

    1948-01-01

    The results of wind tunnel tests at NASA Langley targeted at the performance and configurational characteristics of 0.1 and 0.13 scale model spanwise blowing (SWB) jet wing concepts are reported. The concept involves redirection of engine compressor bleed air to provide SWB at the fuselage-wing juncture near the wing leading edge. The tests covered the orientation of the outer panel nozzles, the effects of SWB operation on the performance of leading and trailing edge flaps and the effects of SWB on lateral stability. The trials were run at low speeds and angles of attack from 24-45 deg (landing). Both lift and longitudinal stability improved with the SWB, stall and leading edge vortex breakdown were delayed and performance increased with the SWB rate. Lateral stability was degraded below 20 deg angle of attack while instabilities were delayed above 20 deg due to roll damping.

  12. Experimental investigation of the aerodynamic effects of distributed spanwise blowing on a fighter configuration

    NASA Technical Reports Server (NTRS)

    Huffman, J. K.; Hahne, D. E.; Johnson, T. D., Jr.

    1948-01-01

    The results of wind tunnel tests at NASA Langley targeted at the performance and configurational characteristics of 0.1 and 0.13 scale model spanwise blowing (SWB) jet wing concepts are reported. The concept involves redirection of engine compressor bleed air to provide SWB at the fuselage-wing juncture near the wing leading edge. The tests covered the orientation of the outer panel nozzles, the effects of SWB operation on the performance of leading and trailing edge flaps and the effects of SWB on lateral stability. The trials were run at low speeds and angles of attack from 24-45 deg (landing). Both lift and longitudinal stability improved with the SWB, stall and leading edge vortex breakdown were delayed and performance increased with the SWB rate. Lateral stability was degraded below 20 deg angle of attack while instabilities were delayed above 20 deg due to roll damping.

  13. Determining potential 30/20 GHZ domestic satellite system concepts and establishment of a suitable experimental configuration

    NASA Technical Reports Server (NTRS)

    Stevens, G. H.; Anzic, G.

    1979-01-01

    NASA is conducting a series of millimeter wave satellite communication systems and market studies to: (1) determine potential domestic 30/20 GHz satellite concepts and market potential, and (2) establish the requirements for a suitable technology verification payload which, although intended to be modest in capacity, would sufficiently demonstrate key technologies and experimentally address key operational issues. Preliminary results and critical issues of the current contracted effort are described. Also included is a description of a NASA-developed multibeam satellite payload configuration which may be representative of concepts utilized in a technology flight verification program.

  14. Comparison of Theoretical and Experimental Level Values of the n = 2 Configurations in the Nitrogen Isoelectronic Sequence

    NASA Astrophysics Data System (ADS)

    Edlén, Bengt

    1984-08-01

    Observed level intervals within and between the configurations 2s2 2p3, 2s2p4 and 2p5 of the nitrogen sequence are compared with the corresponding theoretical values derived from the tables of Cheng, Kim and Desclaux. The differences are expressed by suitable functions of Z which give the systematic correction to the theoretical values and reveal the accidental errors in the experimental values. The technique is the same as was used in previous examinations of the Li, Be, B, O and F sequences. The results are summarized in tables of recommended level values (Z = 10-36) and recalculated wavelengths.

  15. Experimental aerodynamic characteristics at Mach numbers from 0.60 to 2.70 of two supersonic cruise fighter configurations

    NASA Technical Reports Server (NTRS)

    Dollyhigh, S. M.

    1979-01-01

    Two 0.085-scale full span wind-tunnel models of a Mach 1.60 design supercruiser configuration were tested at Mach numbers from 0.60 to 2.70. One model incorporated a varying dihedral (swept-up) wing to obtain the desired lateral-directional characteristics; the other incorporated more conventional twin vertical tails. The data from the wind-tunnel tests are presented without analysis.

  16. GENERIC DEGRADATION SCENARIO AND CONFIGURATION ANALYSIS FOR DOE CODISPOSAL WASTE PACKAGE

    SciTech Connect

    S.F. A. Deng

    1999-11-10

    The purpose of this analysis is to develop a generic set of degradation scenarios and associated configurations for various Department of Energy (DOE) spent nuclear fuel (SNF) types when codisposed with the high-level waste (HLW) glass inside a waste package (WP). The degradation takes place inside the WP. These scenarios and configurations are developed as refinements of the standard degradation scenarios and potentially critical configuration classes given in Section 3.1 of the ''Disposal Criticality Analysis Methodology Topical Report'' (Ref. 1). Certain degradation scenarios and configurations will change when EDA II design is baselined. In accordance with AP-3.10Q, Revision 0, ICN 0, a work direction was developed, issued, and used in the preparation of this document (Ref. 13, p. 7).

  17. Load support system analysis high speed input pinion configuration

    NASA Technical Reports Server (NTRS)

    Gassel, S. S.; Pirvics, J.

    1979-01-01

    An analysis and a series of computerized calculations were carried out to explore competing prototype design concepts of a shaft and two taper-roller bearings systems to support the high-speed input pinion of an advanced commercial helicopter transmission. The results were used to evaluate designs both for a straddle arrangement where the pinion gear is located between the bearings and for a cantilever arrangement where the pinion is outboard of the two bearings. Effects of varying parameters including applied gear load, preload, wall thickness, interference fits, bearing spacing and pinion gear location on system rigidity, load distribution and bearing rating life were assessed. A comparison of the bearing load distributions for these designs demonstrated that the straddle more equally distributes both radial and axial loads. The performance of these designs over a range of shaft rotational speeds, with lubrication and friction effects included, is also discussed.

  18. Configuration Analysis Tool (CAT). System Description and users guide (revision 1)

    NASA Technical Reports Server (NTRS)

    Decker, W.; Taylor, W.; Mcgarry, F. E.; Merwarth, P.

    1982-01-01

    A system description of, and user's guide for, the Configuration Analysis Tool (CAT) are presented. As a configuration management tool, CAT enhances the control of large software systems by providing a repository for information describing the current status of a project. CAT provides an editing capability to update the information and a reporting capability to present the information. CAT is an interactive program available in versions for the PDP-11/70 and VAX-11/780 computers.

  19. Experimental investigation of advanced hub and pylon fairing configurations to reduce helicopter drag

    NASA Technical Reports Server (NTRS)

    Martin, D. M.; Mort, R. W.; Young, L. A.; Squires, P. K.

    1993-01-01

    New hub and pylon fairing designs were tested on a one-fifth scale Bell Helicopter Textron Model 222 helicopter with a bearingless main rotor hub. The blades were not installed for this test. The fairings were designed by NASA and Bell Helicopter Textron under a joint program and tested in the Ames Research Center 7-by 10-Foot Wind Tunnel. All six aircraft forces and moments were measured using the tunnel scales system. Previous research has identified the integrated hub and pylon fairing approach as the most efficient in reducing helicopter drag. Three hub fairings and three pylon fairings were tested (in various combinations) resulting in a total of 16 different configurations, including the baseline helicopter model without fairings. The geometry of the new fairings is described in detail. Test results are presented in the form of plots of the six model forces and moments. The data show that model drag can be reduced by as much as 20 percent by combining a small hub fairing (that has a circular arc upper surface and a flat lower surface) integrated with a nontapered pylon fairing. To minimize drag, the gap between the lower surface of the hub and upper surface of the pylon fairing must be kept to a minimum. Results show that the aerodynamic effects of the fairings on static longitudinal and directional stability can also be important.

  20. The expanding universe of mass analyzer configurations for biological analysis.

    PubMed

    Calvete, Juan J

    2014-01-01

    Mass spectrometry (MS) is an analytical technique that measures the mass-to-charge ratio of electrically charged gas-phase particles. All mass spectrometers combine ion formation, mass analysis, and ion detection. Although mass analyzers can be regarded as sophisticated devices that manipulate ions in space and time, the rich diversity of possible ways to combine ion separation, focusing, and detection in dynamic mass spectrometers accounts for the large number of instrument designs. A historical perspective of the progress in mass spectrometry that since 1965 until today have contributed to position this technique as an indispensable tool for biological research has been recently addressed by a privileged witness of this golden age of MS (Gelpí J. Mass Spectrom 43:419-435, 2008; Gelpí J. Mass Spectrom 44:1137-1161, 2008). The aim of this chapter is to highlight the view that the operational principles of mass spectrometry can be understood by a simple mathematical language, and that an understanding of the basic concepts of mass spectrometry is necessary to take the most out of this versatile technique.

  1. Laser ignition of an experimental combustion chamber with a multi-injector configuration at low pressure conditions

    NASA Astrophysics Data System (ADS)

    Börner, Michael; Manfletti, Chiara; Kroupa, Gerhard; Oschwald, Michael

    2017-06-01

    In search of reliable and light-weight ignition systems for re-ignitable upper stage engines, a laser ignition system was adapted and tested on an experimental combustion chamber for propellant injection into low combustion chamber pressures at 50-80 mbar. The injector head pattern consisted of five coaxial injector elements. Both, laser-ablation-driven ignition and laser-plasma-driven ignition were tested for the propellant combination liquid oxygen and gaseous hydrogen. The 122 test runs demonstrated the reliability of the ignition system for different ignition configurations and negligible degradation due to testing. For the laser-plasma-driven scheme, minimum laser pulse energies needed for 100% ignition probability were found to decrease when increasing the distance of the ignition location from the injector faceplate with a minimum of 2.6 mJ. For laser-ablation-driven ignition, the minimum pulse energy was found to be independent of the ablation material tested and was about 1.7 mJ. The ignition process was characterized using both high-speed Schlieren and OH* emission diagnostics. Based on these findings and on the increased fiber-based pulse transport capabilities recently published, new ignition system configurations for space propulsion systems relying on fiber-based pulse delivery are formulated. If the laser ignition system delivers enough pulse energy, the laser-plasma-driven configuration represents the more versatile configuration. If the laser ignition pulse power is limited, the application of laser-ablation-driven ignition is an option to realize ignition, but implies restrictions concerning the location of ignition.

  2. Investigation of lower hybrid wave coupling and current drive experiments at different configurations in experimental advanced superconducting tokamak

    NASA Astrophysics Data System (ADS)

    Ding, B. J.; Qin, Y. L.; Li, W. K.; Li, M. H.; Kong, E. H.; Zhang, L.; Ekedahl, A.; Peysson, Y.; Decker, J.; Wang, M.; Xu, H. D.; Hu, H. C.; Xu, G. S.; Shan, J. F.; Liu, F. K.; Zhao, Y. P.; Wan, B. N.; Li, J. G.; Group, EAST

    2011-08-01

    Using a 2 MW 2.45 GHz lower hybrid wave (LHW) system installed in experimental advanced superconducting tokamak, we have systematically carried out LHW-plasma coupling and lower hybrid current drive experiments in both divertor (double null and lower single null) and limiter plasma configuration with plasma current (Ip) ˜ 250 kA and central line averaged density (ne) ˜ 1.0-1.3 × 1019 m-3 recently. Results show that the reflection coefficient (RC) first is flat up to some distance between plasma and LHW grill, and then increases with the distance. Studies indicate that with the same plasma parameters, the best coupling is obtained in the limiter case (with plasma leaning on the inner wall), followed by the lower single null, and the one with the worst coupling is the double null configuration, explained by different magnetic connection length. The RCs in the different poloidal rows show that they have different coupling characteristics, possibly due to local magnetic connection length. Current drive efficiency has been investigated by a least squares fit with N//peak=2.1, where N//peak is the peak value of parallel refractive index of the launched wave. Results show that there is no obvious difference in the current drive efficiency between double null and lower single null cases, whereas the efficiency is somewhat small in the limiter configuration. This is in agreement with the ray tracing/Fokker-Planck code simulation by LUKE/C3PO and can be interpreted by the power spectrum up-shift factor in different plasma configurations. A transformer recharge is realized with ˜0.8 MW LHW power and the energy conversion efficiency from LHW to poloidal field energy is about 2%.

  3. Laser ignition of an experimental combustion chamber with a multi-injector configuration at low pressure conditions

    NASA Astrophysics Data System (ADS)

    Börner, Michael; Manfletti, Chiara; Kroupa, Gerhard; Oschwald, Michael

    2017-09-01

    In search of reliable and light-weight ignition systems for re-ignitable upper stage engines, a laser ignition system was adapted and tested on an experimental combustion chamber for propellant injection into low combustion chamber pressures at 50-80 mbar. The injector head pattern consisted of five coaxial injector elements. Both, laser-ablation-driven ignition and laser-plasma-driven ignition were tested for the propellant combination liquid oxygen and gaseous hydrogen. The 122 test runs demonstrated the reliability of the ignition system for different ignition configurations and negligible degradation due to testing. For the laser-plasma-driven scheme, minimum laser pulse energies needed for 100% ignition probability were found to decrease when increasing the distance of the ignition location from the injector faceplate with a minimum of 2.6 mJ. For laser-ablation-driven ignition, the minimum pulse energy was found to be independent of the ablation material tested and was about 1.7 mJ. The ignition process was characterized using both high-speed Schlieren and OH* emission diagnostics. Based on these findings and on the increased fiber-based pulse transport capabilities recently published, new ignition system configurations for space propulsion systems relying on fiber-based pulse delivery are formulated. If the laser ignition system delivers enough pulse energy, the laser-plasma-driven configuration represents the more versatile configuration. If the laser ignition pulse power is limited, the application of laser-ablation-driven ignition is an option to realize ignition, but implies restrictions concerning the location of ignition.

  4. Computational fluid dynamics analysis in microbial fuel cells with different anode configurations.

    PubMed

    Kim, Jiyeon; Kim, Hongsuck; Kim, Byunggoon; Yu, Jaecheul

    2014-01-01

    A key criterion in microbial fuel cell (MFC) design is that the bio-electrochemical reaction between bacteria and the bulk solution should occur evenly on the electrode surface in order to improve electricity generation. However, experimental optimization of MFC design over a wide range of conditions is limited. Computational fluid dynamics (CFD) technology makes it possible to evaluate physicochemical phenomena such as fluid flows, mass transfer and chemical reaction, which can assist in system optimization. Twelve MFCs (M1-M12) with different internal structures were subjected to CFD analysis. The dead (DS) and working spaces (WS) of the anode compartment were calculated. The flow patterns of the anodic fluid varied according to the internal structures. The WS where the bio-electrochemical reaction can actually occur varied over the range of 0.14-0.57 m(2). Based on the above results, the power densities were estimated under the assumption that a monolayer biofilm was formed on the electrode. M11, with 18 rectangular-type internal structures, showed the largest WS of 0.57 m(2) and a theoretical maximum power density of 0.54 W/m(2). Although the optimization of the MFC configuration with only CFD analysis remains limited, the present study results are expected to provide fundamental data for MFC optimization.

  5. An experimental and numerical investigation of air side heat transfer and flow characteristics on finned plate configuration

    NASA Astrophysics Data System (ADS)

    Gu, Lihao; Ling, Xiang; Peng, Hao

    2012-10-01

    In this paper, a new type of finned plate heat exchanger (FPHE) is presented to recover the waste heat from exhaust flue gases. A finned plate configuration causes low pressure drop and it is especially appropriate for heat transfer at the flue gas side. Meanwhile, this paper presents a detailed experimental and numerical study of convection heat transfer and pressure drop of the new structure. Three-dimensional numerical simulation results using the CFD code FLUENT6.3 were compared with experimental data to select the best model. The heat transfer and pressure drop with different geometry pattern was then studied numerically using the selected model. And the velocity field and temperature distribution of air flow in the finned plate channel are presented with different geometry patterns. These results provide insight into improved designs of FPHEs.

  6. An Experimental and Analytical Evaluation of Wall And Window Retrofit Configurations: Supporting the Residential Retrofit Best Practices Guide

    SciTech Connect

    Stovall, Therese K; Petrie, Thomas; Kosny, Jan; Childs, Phillip W; Atchley, Jerald Allen; Hulvey, Kimberly D

    2007-11-01

    A Retrofit Best Practices Guide was developed to encourage homeowners to consider energy conservation issues whenever they modify their siding or windows. In support of this guide, an experimental program was implemented to measure the performance of a number of possible wall siding and window retrofit configurations. Both thermal and air-leakage measurements were made for a 2.4 x 2.4 m (8 x 8 ft) wall section with and without a 0.9 x 1.2 m (3 x 4 ft) window. The windows tested were previously well-characterized at a dedicated window test facility. A computer model was also used to provide information for the Best Practices Guide. The experimental data for walls and windows were used in conjunction with this model to estimate the total annual energy savings for several typical houses in a number of different locations.

  7. Hypersonic Boundary/Shear Layer Transition for Blunt to Slender Configurations - A NASA Langley Experimental Perspective

    DTIC Science & Technology

    2004-10-01

    performances des vehicules aeriens militaires de l’OTAN par la gestion de l’interaction entre la transition et le decollement de la couche limite)., The...the Martian atmosphere. After an orbital rendezvous, the material samples would be autonomously transferred to the MSRO and stored in the US-designed...program was to demonstrate an autonomous return from low Earth orbit of an experimental flight test vehicle, with the ultimate goal of supporting

  8. Biomechanical Modeling Analysis of Loads Configuration for Squat Exercise

    NASA Technical Reports Server (NTRS)

    Gallo, Christopher A.; Thompson, William K.; Lewandowski, Beth E.; Jagodnik, Kathleen; De Witt, John K.

    2017-01-01

    the applied device load and the dual cable long bar or single cable T-bar interface between the test subject and the device. Data is also obtained using free weights with the identical loading for a comparison to the resistively loaded exercise device trials. The data drives the OpenSim biomechanical model, which has been scaled to match the anthropometrics of the test subject, to calculate the body loads. RESULTS Lower body kinematics, joint moments, joint forces and muscle forces are obtained from the OpenSim biomechanical analysis of the squat exercises under different loading conditions. Preliminary results from the model for the loading conditions will be presented as will hypotheses developed for follow on work.

  9. C2 for Computer Networked Operations: Using Computational Experimentation to Identify Effects on Performance in Organizational Configurations within the Larger Network-Centric Environment

    DTIC Science & Technology

    2008-06-01

    defense, attack, and exploitation, the technological capabilities are growing exponentially, as is the rate of data exchange, yet the organizational ...to improve CNO performance. The key research question is, which organizational configurations provide the best CNO performance within the network...CNO set within different organizational configurations taken from both theory and practice, and we employ the method of computational experimentation

  10. Comparison of Theoretical and Experimental Level Values of the n = 2 Configurations in the Boron Isoelectronic Sequence

    NASA Astrophysics Data System (ADS)

    Edlén, Bengt

    1983-10-01

    The examination of the level values of the n = 2 configurations, which was recently carried through for ions iso-electronic with Li, Be, O and F, has now been extended to the configurations 2s22p, 2s2p2 and 2p3 of the boron sequence. In this study, expressions of the form A + B(Z - C)-1 + a(Z - s)x are derived for the difference between observed and theoretical values of selected level intervals, the theoretical values being based on the calculations of Cheng, Kim and Desclaux. By this procedure, accidental errors in the experimental data are smoothed out and missing data are interpolated or extrapolated beyond the range of observations. In the case of the two strongly interacting levels 2s2p2 2S1/2, 2P1/2, however, the theory fails to reproduce the effects of the "avoided crossing" well enough to provide a useful frame of reference, and a more primitive method of extrapolation had to be used. The results of the examination are summarized in a table of recommended values for the 14 excited levels of the n = 2 complex, covering the range from Z = 7 to Z = 36, and a corresponding table of recalculated wavelengths, including intersystem combinations. Some experimental data reported in the literature are found to need revision.

  11. Evaluation of different synchrotron beamline configurations for X-ray fluorescence analysis of environmental samples.

    PubMed

    Barberie, Sean R; Iceman, Christopher R; Cahill, Catherine F; Cahill, Thomas M

    2014-08-19

    Synchrotron radiation X-ray fluorescence (SR-XRF) is a powerful elemental analysis tool, yet synchrotrons are large, multiuser facilities that are generally not amenable to modification. However, the X-ray beamlines from synchrotrons can be modified by simply including X-ray filters or removing monochromators to improve the SR-XRF analysis. In this study, we evaluated four easily applied beamline configurations for the analysis of three representative environmental samples, namely a thin aerosol sample, an intermediate thickness biological sample, and a thick rare earth mineral specimen. The results showed that the "white beam" configuration, which was simply the full, polychromatic output of the synchrotron, was the optimal configuration for the analysis of thin samples with little mass. The "filtered white beam" configuration removed the lower energy X-rays from the excitation beam so it gave better sensitivity for elements emitting more energetic X-rays. The "filtered white beam-filtered detector" configuration sacrifices the lower energy part of the spectrum (<15 keV) for improved sensitivity in the higher end (∼26 to 48 keV range). The use of a monochromatic beam, which tends to be the standard mode of operation for most SR-XRF analyses reported in the literature, gave the least sensitive analysis.

  12. Concept report: Experimental vector magnetograph (EXVM) operational configuration balloon flight assembly

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The observational limitations of earth bound solar studies has prompted a great deal of interest in recent months in being able to gain new scientific perspectives through, what should prove to be, relatively low cost flight of the magnetograph system. The ground work done by TBE for the solar balloon missions (originally planned for SOUP and GRID) as well as the rather advanced state of assembly of the EXVM has allowed the quick formulation of a mission concept for the 30 cm system currently being assembled. The flight system operational configuration will be discussed as it is proposed for short duration flight (on the order of one day) over the continental United States. Balloon hardware design requirements used in formulation of the concept are those set by the National Science Balloon Facility (NSBF), the support agency under NASA contract for flight services. The concept assumes that the flight hardware assembly would come together from three development sources: the scientific investigator package, the integration contractor package, and the NSBF support system. The majority of these three separate packages can be independently developed; however, the computer control interfaces and telemetry links would require extensive preplanning and coordination. A special section of this study deals with definition of a dedicated telemetry link to be provided by the integration contractor for video image data for pointing system performance verification. In this study the approach has been to capitalize to the maximum extent possible on existing hardware and system design. This is the most prudent step that can be taken to reduce eventual program cost for long duration flights. By fielding the existing EXVM as quickly as possible, experience could be gained from several short duration flight tests before it became necessary to commit to major upgrades for long duration flights of this system or of the larger 60 cm version being considered for eventual development.

  13. Experimental studies of field-reversed-configuration (FRC) confinement in FRX-C

    SciTech Connect

    Siemon, R.E.; Armstrong, W.T.; Bartsch, R.R.

    1982-01-01

    A primary purpose of the large bore (0.5 m dia.) FRX-C field-reversed theta pinch experiment is to study the scaling of plasma particle containment time, tau/sub N/, with major radius, R, of the field-reversed configuration (FRC). At 20 mtorr fill pressure the FRX-C plasma parameters, anti n approx. 4 x 10/sup 15/ c/sup -3/, T/sub e/ approx. 100 eV, T/sub i/ approx. 150 eV, are comparable to those obtained in the smaller bore (0.25 m dia.) FRX-B device. Under these conditions, the present measurement of particle confinement time in FRX-C is tau/sub N/ approx. 140 ..mu..s, consistent with the scaling tau/sub N/ ..cap alpha.. R/sup 2/, when compared with the earlier FRX-B results. This favorable scaling has been observed with R/rho/sub i/ approx. 30 (rho/sub i/ = ion gyro radius), twice as large as in FRX-B, despite theoretical indications that various MHD instabilities would appear as R/rho/sub i/ was increased. The characteristics of hotter, neutron generating FRC plasma produced at lower fill pressure (5 mtorr), where anti n approx. 2 x 10/sup 15/ cm/sup -3/, T/sub e/ approx. 170 eV, T/sub i/ approx. 600 eV, are also presented. In this plasma regime an accurate determination of tau/sub N/ is difficult because of the short stable period observed.

  14. Experimental and theoretical calculation studies on the structure elucidation and absolute configuration of calyxins from Alpinia katsumadai.

    PubMed

    Wang, Xiao-Bing; Yang, Chang-Shui; Luo, Jian-Guang; Zhang, Chao; Luo, Jun; Yang, Ming-Hua; Kong, Ling-Yi

    2017-06-01

    Six novel calyxins, named calyxin T-W, ent-calyxin T and ent-calyxin U were isolated from the seeds of Alpinia katsumadai Hayata. Their relative configurations were elucidated by means of detailed UV, IR, NMR and MS spectroscopic data. Their absolute configurations were assigned by collaborative studies on single crystal X-ray diffraction analysis, Mosher's method, electronic circular dichroism (ECD), optical rotation and theoretical calculations. These compounds are Friedel-Cranft alkylation adducts composed of coexisted diarylheptanoids and flavanone from the seeds of Alpinia katsumadai. The antiproliferative activity of the six compounds against NCI-H460, HeLa, SMMC-7721 and HCT-116 cell lines was also reported, and most of them showed moderate to strong activities. Copyright © 2017. Published by Elsevier B.V.

  15. Parametric study and performance analysis of hybrid rocket motors with double-tube configuration

    NASA Astrophysics Data System (ADS)

    Yu, Nanjia; Zhao, Bo; Lorente, Arnau Pons; Wang, Jue

    2017-03-01

    The practical implementation of hybrid rocket motors has historically been hampered by the slow regression rate of the solid fuel. In recent years, the research on advanced injector designs has achieved notable results in the enhancement of the regression rate and combustion efficiency of hybrid rockets. Following this path, this work studies a new configuration called double-tube characterized by injecting the gaseous oxidizer through a head end injector and an inner tube with injector holes distributed along the motor longitudinal axis. This design has demonstrated a significant potential for improving the performance of hybrid rockets by means of a better mixing of the species achieved through a customized injection of the oxidizer. Indeed, the CFD analysis of the double-tube configuration has revealed that this design may increase the regression rate over 50% with respect to the same motor with a conventional axial showerhead injector. However, in order to fully exploit the advantages of the double-tube concept, it is necessary to acquire a deeper understanding of the influence of the different design parameters in the overall performance. In this way, a parametric study is carried out taking into account the variation of the oxidizer mass flux rate, the ratio of oxidizer mass flow rate injected through the inner tube to the total oxidizer mass flow rate, and injection angle. The data for the analysis have been gathered from a large series of three-dimensional numerical simulations that considered the changes in the design parameters. The propellant combination adopted consists of gaseous oxygen as oxidizer and high-density polyethylene as solid fuel. Furthermore, the numerical model comprises Navier-Stokes equations, k-ε turbulence model, eddy-dissipation combustion model and solid-fuel pyrolysis, which is computed through user-defined functions. This numerical model was previously validated by analyzing the computational and experimental results obtained for

  16. Using Configural Frequency Analysis as a Person-Centered Analytic Approach with Categorical Data

    ERIC Educational Resources Information Center

    Stemmler, Mark; Heine, Jörg-Henrik

    2017-01-01

    Configural frequency analysis and log-linear modeling are presented as person-centered analytic approaches for the analysis of categorical or categorized data in multi-way contingency tables. Person-centered developmental psychology, based on the holistic interactionistic perspective of the Stockholm working group around David Magnusson and Lars…

  17. An Analysis of Spatial Configuration and its Application to Research in Higher Education.

    ERIC Educational Resources Information Center

    Cole, Nancy S.; Cole, James W. L.

    This paper presents an analysis of the spatial configuration of variables in a multivariate system. The purpose of the analysis is to make clearer the relationships among the variables by locating them in a minimally-dimensioned space. Similarly, individuals are located in the smaller space and related to each other on the basis of the variables…

  18. Noise characteristics of upper surface blown configurations. Experimental program and results

    NASA Technical Reports Server (NTRS)

    Brown, W. H.; Searle, N.; Blakney, D. F.; Pennock, A. P.; Gibson, J. S.

    1977-01-01

    An experimental data base was developed from the model upper surface blowing (USB) propulsive lift system hardware. While the emphasis was on far field noise data, a considerable amount of relevant flow field data were also obtained. The data were derived from experiments in four different facilities resulting in: (1) small scale static flow field data; (2) small scale static noise data; (3) small scale simulated forward speed noise and load data; and (4) limited larger-scale static noise flow field and load data. All of the small scale tests used the same USB flap parts. Operational and geometrical variables covered in the test program included jet velocity, nozzle shape, nozzle area, nozzle impingement angle, nozzle vertical and horizontal location, flap length, flap deflection angle, and flap radius of curvature.

  19. Experimental investigation of microwave interaction with magnetoplasma in miniature multipolar configuration using impedance measurements

    NASA Astrophysics Data System (ADS)

    Dey, Indranuj; Toyoda, Yuji; Yamamoto, Naoji; Nakashima, Hideki

    2014-09-01

    A miniature microwave plasma source employing both radial and axial magnetic fields for plasma confinement has been developed for micro-propulsion applications. Plasma is initiated by launching microwaves via a short monopole antenna to circumvent geometrical cutoff limitations. The amplitude and phase of the forward and reflected microwave power is measured to obtain the complex reflection coefficient from which the equivalent impedance of the plasma source is determined. Effect of critical plasma density condition is reflected in the measurements and provides insight into the working of the miniature plasma source. A basic impedance calculation model is developed to help in understanding the experimental observations. From experiment and theory, it is seen that the equivalent impedance magnitude is controlled by the coaxial discharge boundary conditions, and the phase is influenced primarily by the plasma immersed antenna impedance.

  20. Experimental investigation of microwave interaction with magnetoplasma in miniature multipolar configuration using impedance measurements

    SciTech Connect

    Dey, Indranuj Toyoda, Yuji; Yamamoto, Naoji; Nakashima, Hideki

    2014-09-15

    A miniature microwave plasma source employing both radial and axial magnetic fields for plasma confinement has been developed for micro-propulsion applications. Plasma is initiated by launching microwaves via a short monopole antenna to circumvent geometrical cutoff limitations. The amplitude and phase of the forward and reflected microwave power is measured to obtain the complex reflection coefficient from which the equivalent impedance of the plasma source is determined. Effect of critical plasma density condition is reflected in the measurements and provides insight into the working of the miniature plasma source. A basic impedance calculation model is developed to help in understanding the experimental observations. From experiment and theory, it is seen that the equivalent impedance magnitude is controlled by the coaxial discharge boundary conditions, and the phase is influenced primarily by the plasma immersed antenna impedance.

  1. Experimental imaging performance evaluation for alternate configurations of undersea pulsed laser serial imagers

    NASA Astrophysics Data System (ADS)

    Dalgleish, Fraser R.; Vuorenkoski, Anni K.; Nootz, Gero; Ouyang, Bing; Caimi, Frank M.

    2011-06-01

    This paper examines imaging performance bounds for undersea electro-optic identification (EOID) sensors that use pulsed laser line scanners to form serial images, typically utilizing one laser pulse for each formed image element. The experimental results presented include the use of two distinct imaging geometries; firstly where the laser source and single element optical detector are nearly co-aligned (near monostatic) and secondly where the laser source is deployed on a separate platform positioned closer to the target (bistatic) to minimize source-to-target beam spread, volumetric scatter and attenuation, with the detector being positioned much further from the target. The former system uses synchronous scanning in order to significantly limit the required instantaneous angular acceptance function of the detector and has the desired intention of acquiring only ballistic photons that have directly interacted with the target element and the undesirable property of acquiring snake photon contributions that indirectly arrive into the detector aperture via multiple forward scattering over the two-way propagation path. The latter system utilizes a staring detector with a much wider angular acceptance function, the objective being to deliver maximum photon density to each target element and acquire diffuse, snake and ballistic photon contributions in order to maximize the signal. The objective of this work was to experimentally investigate pulse-to-pulse detection statistics for both imaging geometries in carefully controlled particle suspensions, with and without artificially generated random uncharacterized scattering inhomogeneities to assess potential image performance in realistic conditions where large biological and mineral particles, aggregates, thin biological scattering layers and turbulence will exist. More specifically, the study investigates received pulse energy variance in clear filtered water, as well as various well-characterized particle suspensions

  2. Magnetic configuration flexibility of snowflake divertor for HL-2M [Analysis of snowflake divertor configurations for HL-2M

    SciTech Connect

    Zheng, G. Y.; Xu, X. Q.; Ryutov, D. D.; Pan, Y. D.; Xia, T. Y.

    2014-07-09

    HL-2M (Li, 2013 [1]) is a tokamak device that is under construction. Based on the magnetic coils design of HL-2M, four kinds of divertor configurations are calculated by CORSICA code (Pearlstein et al., 2001 [2]) with the same main plasma parameters, which are standard divertor, exact snowflake divertor, snowflake-plus divertor and snowflake-minus divertor configurations. The potential properties of these divertors are analyzed and presented in this paper: low poloidal field area around X-point, connection length from outside mid-plane to the primary X-point, target plate design and magnetic field shear. The results show that the snowflake configurations not only can reduce the heat load at divertor target plates, but also may improve the magneto-hydrodynamic stability by stronger magnetic shear at the edge. Furthermore, a new divertor configuration, named “tripod divertor”, is designed by adjusting the positions of the two X-points according to plasma parameters and magnetic coils current of HL-2M.

  3. Magnetic configuration flexibility of snowflake divertor for HL-2M [Analysis of snowflake divertor configurations for HL-2M

    DOE PAGES

    Zheng, G. Y.; Xu, X. Q.; Ryutov, D. D.; ...

    2014-07-09

    HL-2M (Li, 2013 [1]) is a tokamak device that is under construction. Based on the magnetic coils design of HL-2M, four kinds of divertor configurations are calculated by CORSICA code (Pearlstein et al., 2001 [2]) with the same main plasma parameters, which are standard divertor, exact snowflake divertor, snowflake-plus divertor and snowflake-minus divertor configurations. The potential properties of these divertors are analyzed and presented in this paper: low poloidal field area around X-point, connection length from outside mid-plane to the primary X-point, target plate design and magnetic field shear. The results show that the snowflake configurations not only can reducemore » the heat load at divertor target plates, but also may improve the magneto-hydrodynamic stability by stronger magnetic shear at the edge. Furthermore, a new divertor configuration, named “tripod divertor”, is designed by adjusting the positions of the two X-points according to plasma parameters and magnetic coils current of HL-2M.« less

  4. Analysis of hydrogen adsorption and surface binding configuration on tungsten using direct recoil spectrometry

    DOE PAGES

    Kolasinski, R. D.; Hammond, K. D.; Whaley, J. A.; ...

    2014-12-03

    In our work, we apply low energy ion beam analysis to examine directly how the adsorbed hydrogen concentration and binding configuration on W(1 0 0) depend on temperature. We exposed the tungsten surface to fluxes of both atomic and molecular H and D. We then probed the H isotopes adsorbed along different crystal directions using 1–2 keV Ne+ ions. At saturation coverage, H occupies two-fold bridge sites on W(1 0 0) at 25 °C. Moreover, the H coverage dramatically changes the behavior of channeled ions, as does reconstruction of the surface W atoms. For the exposure conditions examined here, wemore » find that surface sites remain populated with H until the surface temperature reaches 200 °C. Then, we observe H rapidly desorbing until only a residual concentration remains at 450 °C. Development of an efficient atomistic model that accurately reproduces the experimental ion energy spectra and azimuthal variation of recoiled H is underway.« less

  5. Overview of HATP Experimental Aerodynamics Data for the Baseline F/A-18 Configuration

    NASA Technical Reports Server (NTRS)

    Hall, Robert M.; Murri, Daniel G.; Erickson, Gary E.; Fisher, David F.; Banks, Daniel W.; Lanser, Wendy, R.

    1996-01-01

    Determining the baseline aerodynamics of the F/A-18 was one of the major objectives of the High-Angle-of-Attack Technology Program (HATP). This paper will review the key data bases that have contributed to our knowledge of the baseline aerodynamics and the improvements in test techniques that have resulted from the experimental program. Photographs are given highlighting the forebody and leading-edge-extension (LEX) vortices. Other data representing the impact of Mach and Reynolds numbers on the forebody and LEX vortices will also be detailed. The level of agreement between different tunnels and between tunnels and flight will be illustrated using pressures, forces, and moments measured on a 0.06-scale model tested in the Langley 7- by 10-Foot High Speed Tunnel, a 0.16-scale model in the Langley 30- by 60-Foot Tunnel, a full-scale vehicle in the Ames 80- by 120-Foot Wind Tunnel, and the flight F/A-18 High Alpha Research Vehicle (HARV). Next, creative use of wind tunnel resources that accelerated the validation of the computational fluid dynamics (CFD) codes will be described. Lastly, lessons learned, deliverables, and program conclusions are presented.

  6. Failure Mode Effects Analysis for the RHIC Cryogenic Distribution System First Sextant Test Configuration

    SciTech Connect

    Kane, S.

    1996-12-26

    The RHIC Cryogenic Distribution System previously has been analyzed and documented in the RHIC Cryogenic System Safety Analysis Report, September 6, 1994 and the RHIC SAD. These reports address the Cryogenic Distribution System for the completed Collider. The Collider is not completed for the First Sextant Test, thus the Cryogenic Distribution System must be modified for the First Sextant Test. Additionally, some components were not identified or designed at the time of the original report, and could not be analyzed. Finally, some minor modifications have been made to the configuration originally analyzed in 1994. This report specifically addresses all of the differences in the Cryogenic Distributio system configuration for the RHIC First Sextant Test and updates the analysis of those components whose design has been finalized or changed from the originally analyzed configuration.

  7. Shielding Characteristics Using an Ultrasonic Configurable Fan Artificial Noise Source to Generate Modes - Experimental Measurements and Analytical Predictions

    NASA Technical Reports Server (NTRS)

    Sutliff, Daniel L.; Walker, Bruce E.

    2014-01-01

    An Ultrasonic Configurable Fan Artificial Noise Source (UCFANS) was designed, built, and tested in support of the NASA Langley Research Center's 14x22 wind tunnel test of the Hybrid Wing Body (HWB) full 3-D 5.8% scale model. The UCFANS is a 5.8% rapid prototype scale model of a high-bypass turbofan engine that can generate the tonal signature of proposed engines using artificial sources (no flow). The purpose of the program was to provide an estimate of the acoustic shielding benefits possible from mounting an engine on the upper surface of a wing; a flat plate model was used as the shielding surface. Simple analytical simulations were used to preview the radiation patterns - Fresnel knife-edge diffraction was coupled with a dense phased array of point sources to compute shielded and unshielded sound pressure distributions for potential test geometries and excitation modes. Contour plots of sound pressure levels, and integrated power levels, from nacelle alone and shielded configurations for both the experimental measurements and the analytical predictions are presented in this paper.

  8. C-2U Experimental Transport Analysis

    NASA Astrophysics Data System (ADS)

    Trask, Erik; Beall, M.; Bolte, N.; Deng, B.; Douglass, J.; Gota, H.; Granstedt, E.; Gupta, D.; Osin, D.; Roche, T.; Zhai, K.; TAE Team

    2016-10-01

    Upgrades of the experimental facility at Tri Alpha Energy have led to record Field Reversed Configuration (FRC) performance on the C-2U device. Modifications to magnetic field characteristics and increases in neutral beam power were critical drivers in achieving sustained plasma targets for greater than 5ms. 0D power balance calculations detailing loss channel characteristics and plasma timescales will be presented demonstrating substantial improvements in equilibrium and transport parameters. Tri Alpha Energy, Inc.

  9. Experimental study of the enhanced Raman scattering in the Sarid-type 4-layered attenuated total reflection configurations

    NASA Astrophysics Data System (ADS)

    Lee, Moon-Gyu; Lee, Jai-Hyung; Chang, Joon-Sung

    We experimentally explored the enhanced Raman scattering in pyridine (C 5H 5N) due to the excitation of long range surface plasmons (LRSP's) guided by a symmetrically bounded silver slab in the Sarid-type ATR (attenuated total reflection) configuration. We have observed that, with decreasing the metallic thickness, the absolute enhancement of the Raman cross section increases while the width of the polar angular distribution of the signal decreases. This observed dependence of the enhanced Raman intensity on the thickness of the thin Ag slab and the collecting solid angle is well explained by assuming that the Raman scattering is mediated by LRSP's. The observed maximum enhancement factor is 4 × 10 6 for the 140 Å silver slab which agrees well with the theoretically predicted value of 6 × 10 6.

  10. Experimental evaluation of honeycomb/screen configurations and short contraction section for NASA Lewis Research Center's altitude wind tunnel

    NASA Technical Reports Server (NTRS)

    Burley, Richard R.; Harrington, Douglas E.

    1987-01-01

    An experimental investigation was conducted in the high speed leg of the 0.1 scale model of the proposed Altitude Wind Tunnel to evaluate flow conditioner configurations in the settling chamber and their effect on the flow through the short contraction section. The lowest longitudinal turbulence intensity measured at the contraction-section entrance, 1.2%, was achieved with a honeycomb plus three fine-mesh screens. Turbulence intensity in the test section was estimated to be between 0.1 and 0.2% with the honeycomb plus three fine mesh screens in the settling chamber. Adding screens, however, adversely affected the total pressure profile, causing a small defect near the centerline at the contraction section entrance. No significant boundary layer separation was evident in the short contraction section.

  11. Acute Haemodynamic and Echocardiographic Effects of Multiple Configurations of Left Ventricular Pacing Sites in Acute Myocardial Infarction: Experimental Study.

    PubMed

    Matthaios, I; Kaladaridou, A; Skaltsiotes, E; Agrios, J; Antoniou, A; Georgiopoulos, G; Papadopoulou, E; Pamboucas, C; Toumanidis, S

    2017-04-01

    Left ventricular (LV) pacing is unsuccessful in a significant number of patients, mainly due to sub-optimal LV pacing location. Nevertheless, data about the impact of different pacing sites on LV function in ischaemic myocardium are scarce. The purpose of this study was to investigate the effect of combinations of alternative LV pacing sites on LV mechanics after experimental acute anterior myocardial infarction (AMI), in order to define the optimal configuration. Atrioventricular epicardial pacing at alternative pacing sites was performed in 16 healthy pigs simultaneously, after experimental AMI. Standard right ventricular (RV) apical pacing was combined with: i) LV apex lateral wall; ii) LV basal posterior wall; iii) LV basal anterior wall, and; iv) LV basal anterior wall + LV basal posterior wall. Moreover the pacing configurations of, v) LV basal posterior wall + LV apex lateral wall; vi) LV basal posterior wall + LV basal anterior wall, and; vii) LV basal anterior wall + LV apex lateral wall were also investigated. Haemodynamic parameters, together with classic and novel echocardiographic indices were used, to evaluate the effect of each pacing combination. A speckle tracking technique using EchoPAC software was used. After AMI, the pacing combination of LV apex lateral wall and LV basal posterior wall had the most favourable effect on LV function, leading to similar haemodynamic and torsional effects with sinus rhythm (all variables p>0.05). In pig hearts after AMI, the combination of pacing LV apex lateral wall and LV basal posterior wall managed to maintain the LV function at a level comparable to the sinus rhythm. Copyright © 2016 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  12. Experimental investigation of the inlet detector configuration variation in the flow field at Mach 1.9

    NASA Technical Reports Server (NTRS)

    Hwang, Kyu C.; Tiwari, Surrendra N.; Miley, Stanley J.

    1995-01-01

    In recent years, active research has been conducted to study the technological feasibility of supersonic laminar flow control on the wing of the High Speed Civil Transport (HSCT). For this study, the F-16XL has been chosen due to its highly swept crank wing planform that closely resembles the HSCT configurations. During flights, it is discovered that the shock wave generated from the aircraft inlet introduces disturbances on the wing where the data acquisition is conducted. The flow field about a supersonic inlet is characterized by a complex three dimensional pattern of shock waves generated by the geometrical configuration of a deflector and a cowl lip. Hence, in this study, experimental method is employed to investigate the effects of the variation of deflector configuration on the flow field, and consequently, the possibility of diverting the incoming shock-disturbances away from the test section. In the present experiments, a model composed of a simple circular tube with a triangular deflector is designed to study the deflector length and the deflector base width variation in the flow field. Experimental results indicate that the lowest external pressure ratio is observed at the junction where the deflector lip and the inlet cowl lip merge. Also, it is noted that the external pressure ratio, the internal pressure ratio, the coefficient of spillage drag, and the shock standoff distance decrease as the deflector length increases. In addition, the Redefined Total Pressure Recovery Ratio (RTPRR) increases with an increase in the deflector length. Results from the study of the effect of the deflector's base width variation on the flow field indicate that the lowest external pressure ratio is observed at the junction between the inlet cowl lip and the deflector lip. As the base width of the deflector increases, the external pressure ratio at 0 rotation increases, whereas the external pressure ratio at 180 rotation decreases. In addition, the internal pressure ratio

  13. Temporal Patterns of Variable Relationships in Person-Oriented Research: Longitudinal Models of Configural Frequency Analysis

    ERIC Educational Resources Information Center

    von Eye, Alexander; Mun, Eun Young; Bogat, G. Anne

    2008-01-01

    This article reviews the premises of configural frequency analysis (CFA), including methods of choosing significance tests and base models, as well as protecting [alpha], and discusses why CFA is a useful approach when conducting longitudinal person-oriented research. CFA operates at the manifest variable level. Longitudinal CFA seeks to identify…

  14. Change of Ratings and Ratings of Change as Identified by Configural Frequency Analysis.

    ERIC Educational Resources Information Center

    Lienert, Gustav A.; Oeveste, Hans Zur

    1988-01-01

    Configurational frequency analysis is suggested as a technique for longitudinal research in educational psychology. Testing for types of change of ratings (grades) and for ratings of change is illustrated by data from three courses in statistics from a cohort of 128 students at Marburg University in West Germany. (TJH)

  15. Analysis of the Flight Motions of a Small Deployable Glider Configuration

    NASA Technical Reports Server (NTRS)

    Coe, Paul L., Jr.

    1975-01-01

    An investigation was conducted at the request of the U.S. Air Force Avionics Laboratory to analyze the flight characteristics of a small uncontrolled glider with folding wings. The study consisted of wind-tunnel tests of an actual glider and a theoretical analysis of the performance, stability, and trimmability of the configuration.

  16. Loads analysis and testing of flight configuration solid rocket motor outer boot ring segments

    NASA Technical Reports Server (NTRS)

    Ahmed, Rafiq

    1990-01-01

    The loads testing on in-house-fabricated flight configuration Solid Rocket Motor (SRM) outer boot ring segments. The tests determined the bending strength and bending stiffness of these beams and showed that they compared well with the hand analysis. The bending stiffness test results compared very well with the finite element data.

  17. Interpretation of discrepancies in mass spectroscopy data obtained from different experimental configurations

    NASA Technical Reports Server (NTRS)

    Russell, John M.

    1993-01-01

    Many helium mass spectrometer leak detectors at KSC employ sampling systems that feature hand held sniffer probes. Authors of general leakage-testing literature recommend sniffer probes for leak location but not for quantitative leakage measurement. Their use in the latter application at KSC involves assumptions that may be subtle. The purpose of the research effort reported herein was to establish the significance of indicated leak rates displayed by sniffer-probe equipped leak detectors and to determine whether the use of alternative hardware or testing procedures may reduce the uncertainty of leakage measurements made with them. The report classifies probe-type sampling systems for helium leak detectors according to their internal plumbing (direct or branched), presents a basic analysis of the fluid dynamics in the sampling system in the branched-conduit case, describes the usual test method for measuring the internal supply-to-sample flowrate ratio (a.k.a permeation ratio), and describes a concept for a sponge-tipped probe whose external supply-to-sample flowrate ratio promises to be lower than that of a simple-ended probe. One conclusion is that the main source of uncertainty in the use of probe-type sampling systems for leakage measurement is uncertainty in the external supply-to-sample flowrate ratio. In contrast, the present method for measuring the internal supply-to-sample flowrate ratio is quantitative and satisfactory. The implication is that probes of lower external supply-to-sample flowrate ratio must be developed before this uncertainty may be reduced significantly.

  18. Experimental Thermo-Magnetic Convection Analysis in Tall Rectangular Enclosure

    NASA Astrophysics Data System (ADS)

    Pyrda, L.; Kraszewska, A.

    2016-09-01

    Rectangular enclosure with aspect ratio (AR=height/width) 2 was investigated in experimental thermo-magnetic convection analysis. Experimental enclosure was placed inside superconducting magnet in Rayleigh-Bénard configuration, in position, where magnetic field gradient was enhancing natural convection. Two types of paramagnetic fluid behaviour were identified at different magnetic induction values. It was possible by utilization of Fast Fourier Transform of recorded temperature signals inside experimental enclosure. Presented results shown augmented heat transfer in rectangular enclosure at high magnetic field gradient up to 300%. Transition zone of fluid behaviour for presented experimental setup was observed from RaTM·4-107 to RaTM·1.3·108.

  19. Analysis and optimization of preliminary aircraft configurations in relationship to emerging agility metrics

    NASA Technical Reports Server (NTRS)

    Sandlin, Doral R.; Bauer, Brent Alan

    1993-01-01

    This paper discusses the development of a FORTRAN computer code to perform agility analysis on aircraft configurations. This code is to be part of the NASA-Ames ACSYNT (AirCraft SYNThesis) design code. This paper begins with a discussion of contemporary agility research in the aircraft industry and a survey of a few agility metrics. The methodology, techniques and models developed for the code are then presented. Finally, example trade studies using the agility module along with ACSYNT are illustrated. These trade studies were conducted using a Northrop F-20 Tigershark aircraft model. The studies show that the agility module is effective in analyzing the influence of common parameters such as thrust-to-weight ratio and wing loading on agility criteria. The module can compare the agility potential between different configurations. In addition one study illustrates the module's ability to optimize a configuration's agility performance.

  20. Nonlinear dynamics behavior analysis of the spatial configuration of a tendril-bearing plant

    NASA Astrophysics Data System (ADS)

    Feng, Jingjing; Zhang, Qichang; Wang, Wei; Hao, Shuying

    2017-03-01

    Tendril-bearing plants appear to have a spiraling shape when tendrils climb along a support during growth. The growth characteristics of a tendril-bearer can be simplified to a model of a thin elastic rod with a cylindrical constraint. In this paper, the connection between some typical configuration characteristics of tendrils and complex nonlinear dynamic behavior are qualitatively analyzed. The space configuration problem of tendrils can be explained through the study of the nonlinear dynamic behavior of the thin elastic rod system equation. In this study, the complex non-Z2 symmetric critical orbits in the system equation under critical parameters were presented. A new function transformation method that can effectively maintain the critical orbit properties was proposed, and a new nonlinear differential equations system containing complex nonlinear terms can been obtained to describe the cross section position and direction of a rod during climbing. Numerical simulation revealed that the new system can describe the configuration of a rod with reasonable accuracy. To adequately explain the growing regulation of the rod shape, the critical orbit and configuration of rod are connected in a direct way. The high precision analytical expressions of these complex non-Z2 symmetric critical orbits are obtained by introducing a suitable analytical method, and then these expressions are used to draw the corresponding three-dimensional configuration figures of an elastic thin rod. Combined with actual tendrils on a live plant, the space configuration of the winding knots of tendril is explained by the concept of heteroclinic orbit from the perspective of nonlinear dynamics, and correctness of the theoretical analysis was verified. This theoretical analysis method could also be effectively applied to other similar slender structures.

  1. Validating Network Security Policies via Static Analysis of Router ACL Configuration

    DTIC Science & Technology

    2006-12-01

    ordering were not always effective. They developed a system based on adding new filters that could be applied in all cases. The paper uses the concept...first begin with the development of a tool that can automatically perform static analysis of a network based on packet filters, since packet filter use...was developed , and the algorithm is based on static analysis of router configuration files. Packet filters are seen as the easiest way to control

  2. Simulator evaluation of the low-speed flying qualities of an experimental STOL configuration with an externally blown flap wing or an augmentor wing

    NASA Technical Reports Server (NTRS)

    Powers, B. G.; Kier, D. A.

    1973-01-01

    The low-speed flying qualities of an experimental STOL configuration were evaluated by using a fixed-base six-degree-of-freedom simulation. The configuration had either an externally blown flap (EBF) wing or an augmentor wing (AW). The AW configuration was investigated with two tails, one sized for the AW configuration and a larger one sized for the EBF configuration. The emphasis of the study was on the 70-knot approach task. The stability and control characteristics were compared with existing criteria. Several control systems were investigated for the normal four-engine condition and for the engine-out transient condition. Minimum control and stall speeds were determined for both the three- and four-engine operation.

  3. Complementarity of DFT Calculations, NMR Anisotropy, and ECD for the Configurational Analysis of Brevipolides K-O from Hyptis brevipes.

    PubMed

    Suárez-Ortiz, G Alejandra; Cerda-García-Rojas, Carlos M; Fragoso-Serrano, Mabel; Pereda-Miranda, Rogelio

    2017-01-27

    Brevipolides K-O (1-5), five new cytotoxic 6-(6'-cinnamoyloxy-2',5'-epoxy-1'-hydroxyheptyl)-5,6-dihydro-2H-pyran-2-ones (IC50 values against six cancer cell lines, 1.7-10 μM), were purified by recycling HPLC from Hyptis brevipes. The structures, containing a distinctive tetrahydrofuran ring, were established by comprehensive quantum mechanical calculations and experimental spectroscopic analysis of their NMR and ECD data. Detailed analysis of the experimental NMR (1)H-(1)H vicinal coupling constants in comparison with the corresponding DFT-calculated values at the B3LYP/DGDZVP level confirmed the absolute configuration of 3 and revealed its conformational preferences, which were further strengthened by NOESY correlations. NMR anisotropy experiments by the application of Mosher's ester methodology and chemical correlations were also used to conclude that this novel brevipolide series (1-5) share the same absolute configuration corresponding to C-6(R), C-1'(S), C-2'(R), C-5'(S), and C-6'(S).

  4. Overview of Sensitivity Analysis and Shape Optimization for Complex Aerodynamic Configurations

    NASA Technical Reports Server (NTRS)

    Newman, James C., III; Taylor, Arthur C., III; Barnwell, Richard W.; Newman, Perry A.; Hou, Gene J.-W.

    1999-01-01

    This paper presents a brief overview of some of the more recent advances in steady aerodynamic shape-design sensitivity analysis and optimization, based on advanced computational fluid dynamics (CFD). The focus here is on those methods particularly well-suited to the study of geometrically complex configurations and their potentially complex associated flow physics. When nonlinear state equations are considered in the optimization process, difficulties are found in the application of sensitivity analysis. Some techniques for circumventing such difficulties are currently being explored and are included here. Attention is directed to methods that utilize automatic differentiation to obtain aerodynamic sensitivity derivatives for both complex configurations and complex flow physics. Various examples of shape-design sensitivity analysis for unstructured-grid CFD algorithms are demonstrated for different formulations of the sensitivity equations. Finally, the use of advanced, unstructured-grid CFDs in multidisciplinary analyses and multidisciplinary sensitivity analyses within future optimization processes is recommended and encouraged.

  5. Overview of Sensitivity Analysis and Shape Optimization for Complex Aerodynamic Configurations

    NASA Technical Reports Server (NTRS)

    Newman, Perry A.; Newman, James C., III; Barnwell, Richard W.; Taylor, Arthur C., III; Hou, Gene J.-W.

    1998-01-01

    This paper presents a brief overview of some of the more recent advances in steady aerodynamic shape-design sensitivity analysis and optimization, based on advanced computational fluid dynamics. The focus here is on those methods particularly well- suited to the study of geometrically complex configurations and their potentially complex associated flow physics. When nonlinear state equations are considered in the optimization process, difficulties are found in the application of sensitivity analysis. Some techniques for circumventing such difficulties are currently being explored and are included here. Attention is directed to methods that utilize automatic differentiation to obtain aerodynamic sensitivity derivatives for both complex configurations and complex flow physics. Various examples of shape-design sensitivity analysis for unstructured-grid computational fluid dynamics algorithms are demonstrated for different formulations of the sensitivity equations. Finally, the use of advanced, unstructured-grid computational fluid dynamics in multidisciplinary analyses and multidisciplinary sensitivity analyses within future optimization processes is recommended and encouraged.

  6. Experimental analysis of armouring process

    NASA Astrophysics Data System (ADS)

    Lamberti, Alberto; Paris, Ennio

    Preliminary results from an experimental investigation on armouring processes are presented. Particularly, the process of development and formation of the armour layer under different steady flow conditions has been analyzed in terms of grain size variations and sediment transport rate associated to each size fraction.

  7. A systems engineering analysis of three-point and four-point wind turbine drivetrain configurations

    DOE PAGES

    Guo, Yi; Parsons, Tyler; Dykes, Katherine; ...

    2016-08-24

    This study compares the impact of drivetrain configuration on the mass and capital cost of a series of wind turbines ranging from 1.5 MW to 5.0 MW power ratings for both land-based and offshore applications. The analysis is performed with a new physics-based drivetrain analysis and sizing tool, Drive Systems Engineering (DriveSE), which is part of the Wind-Plant Integrated System Design & Engineering Model. DriveSE uses physics-based relationships to size all major drivetrain components according to given rotor loads simulated based on International Electrotechnical Commission design load cases. The model's sensitivity to input loads that contain a high degree ofmore » variability was analyzed. Aeroelastic simulations are used to calculate the rotor forces and moments imposed on the drivetrain for each turbine design. DriveSE is then used to size all of the major drivetrain components for each turbine for both three-point and four-point configurations. The simulation results quantify the trade-offs in mass and component costs for the different configurations. On average, a 16.7% decrease in total nacelle mass can be achieved when using a three-point drivetrain configuration, resulting in a 3.5% reduction in turbine capital cost. This analysis is driven by extreme loads and does not consider fatigue. Thus, the effects of configuration choices on reliability and serviceability are not captured. Furthermore, a first order estimate of the sizing, dimensioning and costing of major drivetrain components are made which can be used in larger system studies which consider trade-offs between subsystems such as the rotor, drivetrain and tower.« less

  8. A systems engineering analysis of three-point and four-point wind turbine drivetrain configurations

    SciTech Connect

    Guo, Yi; Parsons, Tyler; Dykes, Katherine; King, Ryan N.

    2016-08-24

    This study compares the impact of drivetrain configuration on the mass and capital cost of a series of wind turbines ranging from 1.5 MW to 5.0 MW power ratings for both land-based and offshore applications. The analysis is performed with a new physics-based drivetrain analysis and sizing tool, Drive Systems Engineering (DriveSE), which is part of the Wind-Plant Integrated System Design & Engineering Model. DriveSE uses physics-based relationships to size all major drivetrain components according to given rotor loads simulated based on International Electrotechnical Commission design load cases. The model's sensitivity to input loads that contain a high degree of variability was analyzed. Aeroelastic simulations are used to calculate the rotor forces and moments imposed on the drivetrain for each turbine design. DriveSE is then used to size all of the major drivetrain components for each turbine for both three-point and four-point configurations. The simulation results quantify the trade-offs in mass and component costs for the different configurations. On average, a 16.7% decrease in total nacelle mass can be achieved when using a three-point drivetrain configuration, resulting in a 3.5% reduction in turbine capital cost. This analysis is driven by extreme loads and does not consider fatigue. Thus, the effects of configuration choices on reliability and serviceability are not captured. Furthermore, a first order estimate of the sizing, dimensioning and costing of major drivetrain components are made which can be used in larger system studies which consider trade-offs between subsystems such as the rotor, drivetrain and tower.

  9. A systems engineering analysis of three-point and four-point wind turbine drivetrain configurations

    SciTech Connect

    Guo, Yi; Parsons, Tyler; Dykes, Katherine; King, Ryan N.

    2016-08-24

    This study compares the impact of drivetrain configuration on the mass and capital cost of a series of wind turbines ranging from 1.5 MW to 5.0 MW power ratings for both land-based and offshore applications. The analysis is performed with a new physics-based drivetrain analysis and sizing tool, Drive Systems Engineering (DriveSE), which is part of the Wind-Plant Integrated System Design & Engineering Model. DriveSE uses physics-based relationships to size all major drivetrain components according to given rotor loads simulated based on International Electrotechnical Commission design load cases. The model's sensitivity to input loads that contain a high degree of variability was analyzed. Aeroelastic simulations are used to calculate the rotor forces and moments imposed on the drivetrain for each turbine design. DriveSE is then used to size all of the major drivetrain components for each turbine for both three-point and four-point configurations. The simulation results quantify the trade-offs in mass and component costs for the different configurations. On average, a 16.7% decrease in total nacelle mass can be achieved when using a three-point drivetrain configuration, resulting in a 3.5% reduction in turbine capital cost. This analysis is driven by extreme loads and does not consider fatigue. Thus, the effects of configuration choices on reliability and serviceability are not captured. Furthermore, a first order estimate of the sizing, dimensioning and costing of major drivetrain components are made which can be used in larger system studies which consider trade-offs between subsystems such as the rotor, drivetrain and tower.

  10. Experimental Investigation of a Hypersonic Glider Configuration at a Mach Number of 6 and at Full-Scale Reynolds Numbers

    NASA Technical Reports Server (NTRS)

    Seiff, Alvin; Wilkins, Max E.

    1961-01-01

    The aerodynamic characteristics of a hypersonic glider configuration, consisting of a slender ogive cylinder with three highly swept wings, spaced 120 apart, with the wing chord equal to the body length, were investigated experimentally at a Mach number of 6 and at Reynolds numbers from 6 to 16 million. The objectives were to evaluate the theoretical procedures which had been used to estimate the performance of the glider, and also to evaluate the characteristics of the glider itself. A principal question concerned the viscous drag at full-scale Reynolds number, there being a large difference between the total drags for laminar and turbulent boundary layers. It was found that the procedures which had been applied for estimating minimum drag, drag due to lift, lift curve slope, and center of pressure were generally accurate within 10 percent. An important exception was the non-linear contribution to the lift coefficient which had been represented by a Newtonian term. Experimentally, the lift curve was nearly linear within the angle-of-attack range up to 10 deg. This error affected the estimated lift-drag ratio. The minimum drag measurements indicated that substantial amounts of turbulent boundary layer were present on all models tested, over a range of surface roughness from 5 microinches maximum to 200 microinches maximum. In fact, the minimum drag coefficients were nearly independent of the surface smoothness and fell between the estimated values for turbulent and laminar boundary layers, but closer to the turbulent value. At the highest test Reynolds numbers and at large angles of attack, there was some indication that the skin friction of the rough models was being increased by the surface roughness. At full-scale Reynolds number, the maximum lift-drag ratio with a leading edge of practical diameter (from the standpoint of leading-edge heating) was 4.0. The configuration was statically and dynamically stable in pitch and yaw, and the center of pressure was less

  11. Sensitivity analysis of flexible joint nonholonomic wheeled mobile manipulator in singular configuration

    NASA Astrophysics Data System (ADS)

    Korayem, A. H.; Azimirad, V.; Binabaji, H.; Korayem, M. H.

    2012-03-01

    This paper proposes a method for decreasing jerk and increasing Maximum Allowable Load (MAL) of nonholonomic Wheeled Mobile Manipulator (WMM) considering flexibility of joints in singular conditions. The full dynamic model of nonholonomic WMM contains simultaneous operation of mobile base and manipulator with joint flexibility (in wheels and manipulator) which is presented here. The problem is formulated in terms of the optimal control which leads to a two point boundary value problem. Then Sobol's sensitivity analysis method is applied to determine the optimal values of flexible joint constants subject to the jerk minimization. To illustrate the proposed method, two categories of conditions are considered: conditions containing non-singular configuration and the singular conditions. An example is explained for non-singular condition of nonholonomic WMM in presence of obstacle in which a complex path is generated but there is no singularity in robot configuration. Some examples of occurring singular configuration in final point and moving boundary condition is also presented. The results show that flexibility of the joints near to singular configuration normalizes the sudden movement and jerk implied to actuators. That is why using a rotational spring with a low stiffness coefficient could be helpful to decrease the high jerk and increase the maximum allowable load in mobile robots.

  12. Overview of the C-2 Field-Reversed Configuration Experimental Program and Future Plan on C-2 Upgrade

    NASA Astrophysics Data System (ADS)

    Yang, Xiaokang; Gota, Hiroshi; Binderbauer, Michl; Tuszewski, Michel; Guo, Houyang; Garate, Eusebio; Barnes, Dan; Putvinski, Sergei; Tajima, Toshiki; Sevier, Leigh

    2014-10-01

    C-2 is the world's largest compact-toroid (CT) device at Tri Alpha Energy that produces field-reversed configuration (FRC) plasmas by colliding/merging oppositely-directed CTs and seeks to study the evolution, heating and sustainment effects of neutral-beam (NB) injection into FRCs. Recently, significant progress has been made in C-2 on both technology and physics fronts, achieving ~ 5 ms stable plasmas with a dramatic improvement in confinement. FRCs are stabilized with an edge biasing using end-on plasma-guns and/or electrodes, and are partially sustained with NB injection (20 keV Hydrogen, ~ 4 MW). Recent work to reduce scrape-off layer and radiative losses has succeeded in reducing the average power balance deficit to ~ 1.5 MW. Increasing plasma pressure and electron temperature are now observed during brief periods of the discharge, which indicate a sign of NB injection effect such as accumulating fast-ions as well as heating core/edge plasmas. Highlights of these advances, broader C-2 experimental program, and future plan on upgrading the C-2 device with new NBs (15 keV, up to 10 MW injection power, selectable beam injection angle) will be presented.

  13. Dumbbell-type fullerene-steroid hybrids: a join experimental and theoretical investigation for conformational, configurational, and circular dichroism assignments.

    PubMed

    Ruíz, Alberto; Morera-Boado, Cercis; Almagro, Luis; Coro, Julieta; Maroto, Enrique E; Herranz, María Ángeles; Filippone, Salvatore; Molero, Dolores; Martínez-Álvarez, Roberto; Garcia de la Vega, José M; Suárez, Margarita; Martín, Nazario

    2014-04-18

    New [60]fullerene-steroid conjugates (4-6) have been synthesized by 1,3-dipolar cycloaddition and Bingel-Hirsch cyclopropanation reactions from suitably functionalized epiandrosterone and [60]fullerene. Since a new stereocenter is created in the formation of the Prato monoaduct, two different diastereomers were isolated by HPLC (4, 5) whose absolute configurations were assigned according to the highly reliable "sector rule" on fullerenes. A further reaction of the malonate-containing diastereomer 5 with a second C60 molecule has afforded dumbbell fullerene 6 in which the two fullerene units are covalently connected through an epiandrosterone moiety. The new compounds have been spectroscopically characterized and their redox potentials, determined by cyclic voltametry, reveal three reversible reduction waves for hybrids 4 and 5, whereas these signals are split in dumbbell 6. Theoretical calculations at semiempirical (AM1) and single point B3LYP/6-31G(d) levels have predicted the most stable conformations for the hybrid compounds (4-6), showing the importance of the chlorine atom on the D ring of the steroid. Furthermore, TDDFT calculations have allowed assignments of the experimentally determined circular dichroism (CD) of the [60]fullerene-steroid hybrids based on the sign and position of the Cotton effects, despite the exceptionally large systems under study.

  14. Transonic aeroelastic analysis of launch vehicle configurations. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Filgueirasdeazevedo, Joao Luiz

    1988-01-01

    A numerical study of the aeroelastic stability of typical launch vehicle configurations in transonic flight is performed. Recent computational fluid dynamics techniques are used to simulate the transonic aerodynamic flow fields, as opposed to relying on experimental data for the unsteady aerodynamic pressures. The flow solver is coupled to an appropriate structural representation of the vehicle. The aerodynamic formulation is based on the thin layer approximation to the Reynolds-Averaged Navier-Stokes equations, where the account for turbulent mixing is done by the two-layer Baldwin and Lomax algebraic eddy viscosity model. The structural-dynamic equations are developed considering free-free flexural vibration of an elongated beam with variable properties and are cast in modal form. Aeroelastic analyses are performed by integrating simultaneously in the two sets of equations. By tracing the growth or decay of a perturbed oscillation, the aeroelastic stability of a given constant configuration can be ascertained. The method is described in detail, and results that indicate its application are presented. Applications include some validation cases for the algorithm developed, as well as the study of configurations known to have presented flutter programs in the past.

  15. Scale-4 Analysis of Pressurized Water Reactor Critical Configurations: Volume 5 - North Anna Unit 1 Cycle 5

    SciTech Connect

    Bowman, S.M.

    1993-01-01

    The requirements of ANSI/ANS 8.1 specify that calculational methods for away-from-reactor (AFR) criticality safety analyses be validated against experimental measurements. If credit for the negative reactivity of the depleted (or spent) fuel isotopics is desired, it is necessary to benchmark computational methods against spent fuel critical configurations. This report summarizes a portion of the ongoing effort to benchmark AFR criticality analysis methods using selected critical configurations from commercial pressurized-water reactors (PWR). The analysis methodology selected for all calculations reported herein was the codes and data provided in the SCALE-4 code system. The isotopic densities for the spent fuel assemblies in the critical configurations were calculated using the SAS2H analytical sequence of the SCALE-4 system. The sources of data and the procedures for deriving SAS2H input parameters are described in detail. The SNIKR code module was used to extract the necessary isotopic densities from the SAS2H results and to provide the data in the format required by the SCALE criticality analysis modules. The CSASN analytical sequence in SCALE-4 was used to perform resonance processing of the cross sections. The KENO V.a module of SCALE-4 was used to calculate the effective multiplication factor (k{sub eff}) of each case. The SCALE-4 27-group burnup library containing ENDF/B-IV (actinides) and ENDF/B-V (fission products) data was used for all the calculations. This volume of the report documents the SCALE system analysis of one reactor critical configuration for North Anna Unit 1 Cycle 5. This unit and cycle were chosen for a previous analysis using a different methodology because detailed isotopics from multidimensional reactor calculations were available from the Virginia Power Company. These data permitted comparison of criticality calculations directly using the utility-calculated isotopics to those using the isotopics generated by the SCALE-4 SAS2H

  16. Shock unsteadiness creation and propagation: experimental analysis

    NASA Astrophysics Data System (ADS)

    Benay, R.; Alaphilippe, M.; Severac, N.

    2012-09-01

    The possibility of creating unsteady distortions of the tip shock by waves emitted from an aircraft is assessed experimentally. The model chosen is a cylindrical fore body equipped with a spike. This configuration is known for generating an important level of unsteadiness around the spike in supersonic regime. The wind tunnel Mach number is equal to 2. The experiments show that waves emitted from this source propagate along the tip shock and interact with it. It is then assessed that this interaction produces a periodic distortion of the shock that propagates to the external flow. Unsteady pressure sensors, high speed schlieren films, hot wire probing and laser Doppler velocimetry are used as complementary experimental means. The final result is a coherent representation of the complex mechanism of wave propagation that has been evidenced. The principle of creating unsteady shock deformation by onboard equipments could be examined as a possibly promising method of sonic boom control.

  17. Analysis of the symmetric configuration of the circle of Willis in a series of autopsied corpses.

    PubMed

    Stojanović, Nebojga; Stefanović, Ivica; Kostić, Aleksandar; Radisavejević, Misa; Stojanov, Dragan; Petrović, Sladjana

    2015-04-01

    The forming of the blood vessels network configuration at the base of the brain and interconnecting of blood vessels during the embryogenesis is directly related to the phylogenetic development of the brain and brain structures. A blood vessel configuration at the brain base, in the form of a ring or a hexagon, stands in direct relation to the perfusion needs of certain parts of the brain during its primary differentiation. The aim of this paper was to determine the incidence of certain blood vessel configurations at the base of the brain and understanding their symmetry or asymmetry. Analysis of the blood vessels at the base of the brain was performed on the autopsied subjects. The object of observation was the anterior segment of the circle of Willis consisting of C1- a. carotis interna (ICA), above a. communicaus posterior (PcoA), the segment A1 a. cerebri anterior (ACA) from a. carotis interna bifurcation to the a. communicans anterior (AcoA) and a communicans anterior itself, as well as the posterior segment consisting of PcoA and the segment P1--a. cerebri posterior (PCA) from the a. basilaris bifurcation to the PcoA. For the purpose of grouping the findings, the four basic configuration types of the circle of Willis were identified based on its symmetry or asymmetry. Type-A (symmetric circle of Willis), type-B (asymmetric circle of Willis' due to the unilateral hypoplastic A1-ACA); type-C (symmetric circle of Willis with bilateral symmetric changes on PcoA) and type-D (asymmetric circle of Willis due to the asymmetric changes on PcoA). Autosy was performed on 56 corpses. A total of 41 (73.2%) subjects were recorded with a symmetric configuration of the circle of Willis', of which 27 (48.2%) subjects had type A and 14 (25%) type C. The asymmetric configuration was present in 15 (26.8%) subjects, of whom 9 (16%) had type B and 6 (10.8%) subjects, of whom 9 (16%) had type B and 6 (10.8%) type D. The symmetric Willis group (73.2%) did not have a homogeneous

  18. Bistatic Radar Configuration for Soil Moisture Retrieval: Analysis of the Spatial Coverage

    PubMed Central

    Pierdicca, Nazzareno; De Titta, Ludovico; Pulvirenti, Luca; della Pietra, Giuliano

    2009-01-01

    Some outcomes of a feasibility analysis of a spaceborne bistatic radar mission for soil moisture retrieval are presented in this paper. The study starts from the orbital design of the configuration suitable for soil moisture estimation identified in a previous study. This configuration is refined according to the results of an analysis of the spatial resolution. The paper focuses on the assessment of the spatial coverage i.e., on the verification that an adequate overlap between the footprints of the antennas is ensured and on the duty cycle, that is the fraction of orbital period during which the bistatic data are acquired. A non-cooperating system is considered, in which the transmitter is the C-band Advanced Synthetic Aperture Radar aboard Envisat. The best performances in terms of duty cycle are achieved if the transmitter operates in Wide Swath Mode. The higher resolution Image Swath Modes that comply with the selected configuration have a duty cycle that is never less than 12% and can exceed 21%. When Envisat operates in Wide Swath Mode, the bistatic system covers a wide latitude range across the equator, while in some of the Image Swath Modes, the bistatic measurements, collected from the same orbit, cover mid-latitude areas. In the latter case, it might be possible to achieve full coverage in an Envisat orbit repeat cycle, while, for a very large latitude range such as that covered in Wide Swath Mode, bistatic acquisitions could be obtained over about 65% of the area. PMID:22399996

  19. Optimizing grid computing configuration and scheduling for geospatial analysis: An example with interpolating DEM

    NASA Astrophysics Data System (ADS)

    Huang, Qunying; Yang, Chaowei

    2011-02-01

    Many geographic analyses are very time-consuming and do not scale well when large datasets are involved. For example, the interpolation of DEMs (digital evaluation model) for large geographic areas could become a problem in practical application, especially for web applications such as terrain visualization, where a fast response is required and computational demands exceed the capacity of a traditional single processing unit conducting serial processing. Therefore, high performance and parallel computing approaches, such as grid computing, were investigated to speed up the geographic analysis algorithms, such as DEM interpolation. The key for grid computing is to configure an optimized grid computing platform for the geospatial analysis and optimally schedule the geospatial tasks within a grid platform. However, there is no research focused on this. Using DEM interoperation as an example, we report our systematic research on configuring and scheduling a high performance grid computing platform to improve the performance of geographic analyses through a systematic study on how the number of cores, processors, grid nodes, different network connections and concurrent request impact the speedup of geospatial analyses. Condor, a grid middleware, is used to schedule the DEM interpolation tasks for different grid configurations. A Kansas raster-based DEM is used for a case study and an inverse distance weighting (IDW) algorithm is used in interpolation experiments.

  20. Bistatic radar configuration for soil moisture retrieval: analysis of the spatial coverage.

    PubMed

    Pierdicca, Nazzareno; De Titta, Ludovico; Pulvirenti, Luca; Della Pietra, Giuliano

    2009-01-01

    Some outcomes of a feasibility analysis of a spaceborne bistatic radar mission for soil moisture retrieval are presented in this paper. The study starts from the orbital design of the configuration suitable for soil moisture estimation identified in a previous study. This configuration is refined according to the results of an analysis of the spatial resolution. The paper focuses on the assessment of the spatial coverage i.e., on the verification that an adequate overlap between the footprints of the antennas is ensured and on the duty cycle, that is the fraction of orbital period during which the bistatic data are acquired. A non-cooperating system is considered, in which the transmitter is the C-band Advanced Synthetic Aperture Radar aboard Envisat. The best performances in terms of duty cycle are achieved if the transmitter operates in Wide Swath Mode. The higher resolution Image Swath Modes that comply with the selected configuration have a duty cycle that is never less than 12% and can exceed 21%. When Envisat operates in Wide Swath Mode, the bistatic system covers a wide latitude range across the equator, while in some of the Image Swath Modes, the bistatic measurements, collected from the same orbit, cover mid-latitude areas. In the latter case, it might be possible to achieve full coverage in an Envisat orbit repeat cycle, while, for a very large latitude range such as that covered in Wide Swath Mode, bistatic acquisitions could be obtained over about 65% of the area.

  1. Identifying configurations of behavior change techniques in effective medication adherence interventions: a qualitative comparative analysis.

    PubMed

    Kahwati, Leila; Viswanathan, Meera; Golin, Carol E; Kane, Heather; Lewis, Megan; Jacobs, Sara

    2016-05-04

    Interventions to improve medication adherence are diverse and complex. Consequently, synthesizing this evidence is challenging. We aimed to extend the results from an existing systematic review of interventions to improve medication adherence by using qualitative comparative analysis (QCA) to identify necessary or sufficient configurations of behavior change techniques among effective interventions. We used data from 60 studies in a completed systematic review to examine the combinations of nine behavior change techniques (increasing knowledge, increasing awareness, changing attitude, increasing self-efficacy, increasing intention formation, increasing action control, facilitation, increasing maintenance support, and motivational interviewing) among studies demonstrating improvements in adherence. Among the 60 studies, 34 demonstrated improved medication adherence. Among effective studies, increasing patient knowledge was a necessary but not sufficient technique. We identified seven configurations of behavior change techniques sufficient for improving adherence, which together accounted for 26 (76 %) of the effective studies. The intervention configuration that included increasing knowledge and self-efficacy was the most empirically relevant, accounting for 17 studies (50 %) and uniquely accounting for 15 (44 %). This analysis extends the completed review findings by identifying multiple combinations of behavior change techniques that improve adherence. Our findings offer direction for policy makers, practitioners, and future comparative effectiveness research on improving adherence.

  2. Optomechanical analysis of the flexure mounting configuration of large-aperture laser transport mirror

    NASA Astrophysics Data System (ADS)

    Zhang, Zheng; Quan, Xusong; Wang, Hui; Liu, Tianye; Xiong, Zhao; Yuan, Xiaodong; Rong, Yiming

    2017-02-01

    Motivated by the demand to minimize the mount-induced wavefront aberration of the large-aperture laser transport mirror, a low-stress flexure mounting configuration is proposed. Specific optomechanical analyses, including theoretical modeling, numerical analysis and field experiment, are presented. The mechanical properties of the flexure support were studied specifically. Besides, the relation between the mounting forces and the root-mean-square of the gradients (GRMS) value of the mirror surface is studied. Then, the appropriate value of the bolt preload is set to 500N, with which the GRMS value is just 5.35 nm/cm. The results indicate that the flexure mounting configuration is indeed a feasible and promising method to solve the mount-induced distortion problem of large-aperture optics.

  3. Optimal configuration analysis for the Robotic All-Terrain Lunar Exploration Rover

    SciTech Connect

    Klarer, P.R.; Purvis, J.W.

    1993-01-01

    A robotic rover vehicle designed for use in the exploration of the Lunar surface is described. The Robotic All-Terrain Lunar Exploration Rover (R-A.T.L.E.R-) is a four wheeled all-wheel-drive dual-body vehicle. A uniquely simple method of chassis articulation is employed which allows all four wheels to remain in contact with the ground, even while climbing over step-like obstacles as large as [approximately]1.3 wheel diameters. Skid steering and modular construction are used to produce a simple, rugged, highly agile mobility chassis with fewer parts required compared to other designs being considered for planetary exploration missions. The design configuration, mobility parameters, and performance of several existing R.A.T.L.E.R prototypes are discussed, with emphasis on an analysis of the configuration parameters which directly affect the designs mobility performance.

  4. Optimal configuration analysis for the Robotic All-Terrain Lunar Exploration Rover

    SciTech Connect

    Klarer, P.R.; Purvis, J.W.

    1993-03-01

    A robotic rover vehicle designed for use in the exploration of the Lunar surface is described. The Robotic All-Terrain Lunar Exploration Rover (R-A.T.L.E.R-) is a four wheeled all-wheel-drive dual-body vehicle. A uniquely simple method of chassis articulation is employed which allows all four wheels to remain in contact with the ground, even while climbing over step-like obstacles as large as {approximately}1.3 wheel diameters. Skid steering and modular construction are used to produce a simple, rugged, highly agile mobility chassis with fewer parts required compared to other designs being considered for planetary exploration missions. The design configuration, mobility parameters, and performance of several existing R.A.T.L.E.R prototypes are discussed, with emphasis on an analysis of the configuration parameters which directly affect the designs mobility performance.

  5. Debris prevention analysis for DFI/OFI/OEI (STS-26 configuration only)

    NASA Technical Reports Server (NTRS)

    Richi, Glen A.

    1988-01-01

    The first 3 shuttle flights to use the Redesigned Solid Rocket Motors (RSRMs) will utilize Development Flight Instrumentation (DFI), as well as Operational Flight Instrumentation (OFI), and Operational Environment Instrumentation (OEI). The OFI consists of high pressure transducers used on both RSRMs to monitor the igniter and motor chamber pressure. DFI consists of assorted strain gages, temperature sensors, accelerometers, girth gages, and low level pressure transducers. The latter are installed on the left hand booster to measure post-separation aerodynamic loading. OEI consistes of temperature sensors. After Flight 3, all DFI gages are to be deleted, and only OFI and OEI will be used for subsequent flights. This report deals specifically with debris prevention and hazards concernig the STS-26 flight DFI configuration only. Continued analysis is being done that will adequately address the debris hazards associated with the STS-27 and subsequent flight DFI configurations.

  6. Analysis of payload bay magnetic fields due to dc power multipoint and single point ground configurations

    NASA Technical Reports Server (NTRS)

    Lawton, R. M.

    1976-01-01

    An analysis of magnetic fields in the Orbiter Payload Bay resulting from the present grounding configuration (structure return) was presented and the amount of improvement that would result from installing wire returns for the three dc power buses was determined. Ac and dc magnetic fields at five points in a cross-section of the bay are calculated for both grounding configurations. Y and Z components of the field at each point are derived in terms of a constant coefficient and the current amplitude of each bus. The dc loads assumed are 100 Amperes for each bus. The ac noise current used is a spectrum 6 db higher than the Orbiter equipment limit for narrowband conducted emissions. It was concluded that installing return wiring to provide a single point ground for the dc Buses in the Payload Bay would reduce the ac and dc magnetic field intensity by approximately 30 db.

  7. Transonic perturbation analysis of wing-fuselage-nacelle-pylon configurations with powered jet exhausts

    NASA Technical Reports Server (NTRS)

    Wai, J. C.; Yoshihara, H.; Abeyounis, W. K.

    1982-01-01

    A transonic small perturbation method has been developed for the analysis of general wing-fuselage-nacelle-pylon configurations with powered jet exhausts. Finite difference successive line relaxation algorithm is used to solve the small disturbance potential equation in conservative form. The nacelle tangency condition and the jet exhaust plume contact conditions are fulfilled in a quasi-cylindrical fashion on a surface fitting the Cartesian grid. The pylon tangency condition is treated in a quasi-planar manner as for the wing. Viscous displacement effects on the wing are modeled by suitable shape changes including the placement of a viscous ramp at the base of the shock. Computed results of a transport configuration show satisfactory correlation with test data.

  8. Aero-thermal analysis of lifting body configurations in hypersonic flow

    NASA Astrophysics Data System (ADS)

    Kumar, Sachin; Mahulikar, Shripad P.

    2016-09-01

    The aero-thermal analysis of a hypersonic vehicle is of fundamental interest for designing its thermal protection system. The aero-thermal environment predictions over several critical regions of the hypothesized lifting body vehicle, including the stagnation region of the nose-cap, cylindrically swept leading edges, fuselage-upper, and fuselage-lower surfaces, are discussed. The drag (Λ=70°) and temperature (Λ=80°) minimized sweepback angles are considered in the configuration design of the two hypothesized lifting body shape hypersonic vehicles. The main aim of the present study is to analyze and compare the aero-thermal characteristics of these two lifting body configurations at same heat capacity. Accordingly, a Computational Fluid Dynamics simulation has been carried out at Mach number (M∞=7), H=35 km altitude with zero Angle of Attack. Finally, the material selection for thermal protection system based on these predictions and current methodology is described.

  9. Determination of absolute configuration of an isopimarane-type diterpenoid by experimental and theoretical electronic circular dichroism and vibrational circular dichroism

    NASA Astrophysics Data System (ADS)

    Wang, Zhi-Qiang; Wu, Cheng-Jun; Wang, Zhen-Hui; Huang, Chao; Huang, Jian; Wang, Jin-Hui; Sun, Tie-Min

    2017-10-01

    In this study, the stereochemistry of a new isopimarane-type diterpenoid isolated from the Callicarpa macrophylla Vahl, Callicapene M3, was studied by experimental electronic circular dichroism and vibrational circular dichroism with the aid of TDDFT theoretical calculations. The good consistence between the experimental and simulated circular dichroism has clearly confirmed the absolute configuration of the title compound as (4S, 5S, 9S, 10S, 13S, 14S)-14α-hydroxy-7,15-isopimaradien-18-oic acid.

  10. Control of the glottal configuration in ex vivo human models: quantitative anatomy for clinical and experimental practices.

    PubMed

    Lagier, Aude; Guenoun, Daphné; Legou, Thierry; Espesser, Robert; Giovanni, Antoine; Champsaur, Pierre

    2017-03-01

    The objective of this paper was to identify the determining factors of the glottal prephonatory configuration from the point of view of the resulting muscular actions (i.e., arytenoids adduction, membranous vocal fold adduction, and tension). 21 human non-embalmed excised larynges (12 females and 9 males) were studied. Experiment A (11 larynges) studied four conditions of adduction of the vocal folds and arytenoids. Experiment B (10 larynges) studied the effect of cricothyroid approximation on the vocal fold length and the cricothyroid angle. Experiment A: The mean glottal area significantly decreased from 41.2 mm(2) mean with no adduction, to 10.2 mm(2) mean with arytenoid adduction, to 9.2 mm(2) with membranous vocal fold adduction, and down to 1.1 mm(2) with the combination of arytenoid and membranous adduction. The effect of the task was statistically significant. Experiment B: The length of vocal folds increased from 13.61 mm median to 14.48 mm median, and the cricothyroid angle decreased of 10.05 median along with cricothyroid approximation. The results of experiment A emphasize the sub-division of adductor intrinsic muscles in arytenoids adductors (i.e., LCA and IA), and membranous vocal fold adductor (i.e., TA). The results of experiment B quantify the effect of cricothyroid approximation on the vocal folds length. The implications of these results can be useful in both clinical practice and experimental studies.

  11. Transient analysis and energy optimization of solar heating and cooling systems in various configurations

    SciTech Connect

    Calise, F.; Dentice d'Accadia, M.; Palombo, A.

    2010-03-15

    In this paper, a transient simulation model of solar-assisted heating and cooling systems (SHC) is presented. A detailed case study is also discussed, in which three different configurations are considered. In all cases, the SHC system is based on the coupling of evacuated solar collectors with a single-stage LiBr-H{sub 2}O absorption chiller, and a gas-fired boiler is also included for auxiliary heating, only during the winter season. In the first configuration, the cooling capacity of the absorption chiller and the solar collector area are designed on the basis of the maximum cooling load, and an electric chiller is used as the auxiliary cooling system. The second layout is similar to the first one, but, in this case, the absorption chiller and the solar collector area are sized in order to balance only a fraction of the maximum cooling load. Finally, in the third configuration, there is no electric chiller, and the auxiliary gas-fired boiler is also used in summer to feed the absorption chiller, in case of scarce solar irradiation. The simulation model was developed using the TRNSYS software, and included the analysis of the dynamic behaviour of the building in which the SHC systems were supposed to be installed. The building was simulated using a single-lumped capacitance model. An economic model was also developed, in order to assess the operating and capital costs of the systems under analysis. Furthermore, a mixed heuristic-deterministic optimization algorithm was implemented, in order to determine the set of the synthesis/design variables that maximize the energy efficiency of each configuration under analysis. The results of the case study were analyzed on monthly and weekly basis, paying special attention to the energy and monetary flows of the standard and optimized configurations. The results are encouraging as for the potential of energy saving. On the contrary, the SHC systems appear still far from the economic profitability: however, this is

  12. 1995 NASA High-Speed Research Program Sonic Boom Workshop. Volume 2; Configuration Design, Analysis, and Testing

    NASA Technical Reports Server (NTRS)

    Baize, Daniel G. (Editor)

    1999-01-01

    The High-Speed Research Program and NASA Langley Research Center sponsored the NASA High-Speed Research Program Sonic Boom Workshop on September 12-13, 1995. The workshop was designed to bring together NASAs scientists and engineers and their counterparts in industry, other Government agencies, and academia working together in the sonic boom element of NASAs High-Speed Research Program. Specific objectives of this workshop were to: (1) report the progress and status of research in sonic boom propagation, acceptability, and design; (2) promote and disseminate this technology within the appropriate technical communities; (3) help promote synergy among the scientists working in the Program; and (4) identify technology pacing, the development C, of viable reduced-boom High-Speed Civil Transport concepts. The Workshop was organized in four sessions: Sessions 1 Sonic Boom Propagation (Theoretical); Session 2 Sonic Boom Propagation (Experimental); Session 3 Acceptability Studies-Human and Animal; and Session 4 - Configuration Design, Analysis, and Testing.

  13. Analysis and Evaluation of Error-Proof Systems for Configuration Data Management in Railway Signalling

    NASA Astrophysics Data System (ADS)

    Shimazoe, Toshiyuki; Ishikawa, Hideto; Takei, Tsuyoshi; Tanaka, Kenji

    Recent types of train protection systems such as ATC require the large amounts of low-level configuration data compared to conventional types of them. Hence management of the configuration data is becoming more important than before. Because of this, the authors developed an error-proof system focusing on human operations in the configuration data management. This error-proof system has already been introduced to the Tokaido Shinkansen ATC data management system. However, as effectiveness of the system has not been presented objectively, its full perspective is not clear. To clarify the effectiveness, this paper analyses error-proofing cases introduced to the system, using the concept of QFD and the error-proofing principles. From this analysis, the following methods of evaluation for error-proof systems are proposed: metrics to review the rationality of required qualities are provided by arranging the required qualities according to hazard levels and work phases; metrics to evaluate error-proof systems are provided to improve their reliability effectively by mapping the error-proofing principles onto the error-proofing cases which are applied according to the required qualities and the corresponding hazard levels. In addition, these objectively-analysed error-proofing cases are available to be used as error-proofing-cases database or guidelines for safer HMI design especially for data management.

  14. Analysis of magnetic-dipole transitions in tungsten plasmas using detailed and configuration-average descriptions

    NASA Astrophysics Data System (ADS)

    Na, Xieyu; Poirier, Michel

    2017-06-01

    This paper is devoted to the analysis of transition arrays of magnetic-dipole (M1) type in highly charged ions. Such transitions play a significant role in highly ionized plasmas, for instance in the tungsten plasma present in tokamak devices. Using formulas recently published and their implementation in the Flexible Atomic Code for M1-transition array shifts and widths, absorption and emission spectra arising from transitions inside the 3*n complex of highly-charged tungsten ions are analyzed. A comparison of magnetic-dipole transitions with electric-dipole (E1) transitions shows that, while the latter are better described by transition array formulas, M1 absorption and emission structures reveal some insufficiency of these formulas. It is demonstrated that the detailed spectra account for significantly richer structures than those predicted by the transition array formalism. This is due to the fact that M1 transitions may occur between levels inside the same relativistic configuration, while such inner configuration transitions are not accounted for by the currently available averaging expression. In addition, because of configuration interaction, transition processes involving more than one electron jump, such as 3p1/23d5/2 → 3p3/23d3/2, are possible but not accounted for in the transition array formulas. These missing transitions are collected in pseudo-arrays using a post-processing method described in this paper. The relative influence of inner- and inter-configuration transitions is carefully analyzed in cases of tungsten ions with net charge around 50. The need for an additional theoretical development is emphasized.

  15. Exploratory studies of the cruise performance of upper surface blown configuration: Experimental program, high-speed force tests

    NASA Technical Reports Server (NTRS)

    Braden, J. A.; Hancock, J. P.; Burdges, K. P.; Hackett, J. E.

    1979-01-01

    The work to develop a wing-nacelle arrangement to accommodate a wide range of upper surface blown configuration is reported. Pertinent model and installation details are described. Data of the effects of a wide range of nozzle geometric variations are presented. Nozzle aspect ratio, boattail angle, and chordwise position are among the parameters investigated. Straight and swept wing configurations were tested across a range of nozzle pressure ratios, lift coefficients, and Mach numbers.

  16. Configural frequency analysis as a method of determining patients' preferred decision-making roles in dialysis.

    PubMed

    Loeffert, Sabine; Ommen, Oliver; Kuch, Christine; Scheibler, Fueloep; Woehrmann, Andrej; Baldamus, Conrad; Pfaff, Holger

    2010-09-11

    Numerous studies examined factors in promoting a patient preference for active participation in treatment decision making with only modest success. The purpose of this study was to identify types of patients wishing to participate in treatment decisions as well as those wishing to play a completely active or passive role based on a Germany-wide survey of dialysis patients; using a prediction typal analysis method that defines types as configurations of categories belonging to different attributes and takes particularly higher order interactions between variables into account. After randomly splitting the original patient sample into two halves, an exploratory prediction configural frequency analysis (CFA) was performed on one-half of the sample (n = 1969) and the identified types were considered as hypotheses for an inferential prediction CFA for the second half (n = 1914). 144 possible prediction types were tested by using five predictor variables and control preferences as criterion. An α-adjustment (0.05) for multiple testing was performed by the Holm procedure. 21 possible prediction types were identified as hypotheses in the exploratory prediction CFA; four patient types were confirmed in the confirmatory prediction CFA: patients preferring a passive role show low information seeking preference, above average trust in their physician, perceive their physician's participatory decision-making (PDM)-style positive, have a lower educational level, and are 56-75 years old (Type 1; p < 0.001) or > 76 years old (Type 2; p < 0.001). Patients preferring an active role show high information seeking preference, a higher educational level, and are < 55 years old. They have either below average trust, perceive the PDM-style negative (Type 3; p < 0.001) or above average trust and perceive the PDM-style positive (Type 4; p < 0.001). The method prediction configural frequency analysis was newly introduced to the research field of patient participation and could demonstrate

  17. Monitoring of high-power fiber laser welding based on principal component analysis of a molten pool configuration

    NASA Astrophysics Data System (ADS)

    Xiangdong, Gao; Qian, Wen

    2013-12-01

    There exists plenty of welding quality information on a molten pool during high-power fiber laser welding. An approach for monitoring the high-power fiber laser welding status based on the principal component analysis (PCA) of a molten pool configuration is investigated. An infrared-sensitive high-speed camera was used to capture the molten pool images during laser butt-joint welding of Type 304 austenitic stainless steel plates with a high-power (10 kW) continuous wave fiber laser. In order to study the relationship between the molten pool configuration and the welding status, a new method based on PCA is proposed to analyze the welding stability by comparing the situation when the laser beam spot moves along, and when it deviates from the weld seam. Image processing techniques were applied to process the molten pool images and extract five characteristic parameters. Moreover, the PCA method was used to extract a composite indicator which is the linear combination of the five original characteristics to analyze the different status during welding. Experimental results showed that the extracted composite indicator had a close relationship with the actual welding results and it could be used to evaluate the status of the high-power fiber laser welding, providing a theoretical basis for the monitoring of laser welding quality.

  18. Experimental design method to the weld bead geometry optimization for hybrid laser-MAG welding in a narrow chamfer configuration

    NASA Astrophysics Data System (ADS)

    Bidi, Lyes; Le Masson, Philippe; Cicala, Eugen; Primault, Christophe

    2017-03-01

    The work presented in this paper relates to the optimization of operating parameters of the welding by the experimental design approach. The welding process used is the hybrid laser-MAG welding, which consists in combining a laser beam with an MAG torch, to increase the productivity and reliability of the chamfer filling operation in several passes over the entire height of the chamfer. Each pass, providing 2 mm deposited metal and must provide sufficient lateral penetration of about 0.2 mm. The experimental design method has been used in order to estimate the operating parameters effects and their interactions on the lateral penetration on one hand, and to provide a mathematical model that relates the welding parameters of welding to the objective function lateral penetration on the other hand. Furthermore, in this study, we sought to the identification of the set of optimum parameters sufficient to comply with a constraint on the quality of weld bead. This constraint is to simultaneously obtain a total lateral penetration greater than 0.4 mm and an H/L ratio less than 0.6. In order to obtain this condition, the multi-objective optimization (for both response functions) of a weld bead by the implementation of the plans method using two categories of Experiments Plans, on two levels has been used: the first is a complete experimental design (CED) with 32 tests and the second a fractional experimental design (FED) with 8 tests. A comparative analysis of the implementation of both types of experiments plans identified the advantages and disadvantages for each type of plan.

  19. CFD Analysis of Flexible Thermal Protection System Shear Configuration Testing in the LCAT Facility

    NASA Technical Reports Server (NTRS)

    Ferlemann, Paul G.

    2014-01-01

    This paper documents results of computational analysis performed after flexible thermal protection system shear configuration testing in the LCAT facility. The primary objectives were to predict the shear force on the sample and the sensitivity of all surface properties to the shape of the sample. Bumps of 0.05, 0.10,and 0.15 inches were created to approximate the shape of some fabric samples during testing. A large amount of information was extracted from the CFD solutions for comparison between runs and also current or future flight simulations.

  20. A finite-element analysis for steady and oscillatory subsonic flow around complex configurations

    NASA Technical Reports Server (NTRS)

    Chen, L. T.; Suciu, E. O.; Morino, L.

    1974-01-01

    The problem of potential subsonic flow around complex configurations is considered. The solution is given of an integral equation relating the values of the potential on the surface of the body to the values of the normal derivative, which is known from the boundary conditions. The surface of the body is divided into small (hyperboloidal quadrilateral) surface elements, which are described in terms of the Cartesian components of the four corner points. The values of the potential (and its normal derivative) within each element is assumed to be constant and equal to its value at the centroid of the element. The coefficients of the equation are given by source and doublet integrals over the surface elements. Closed form evaluations of the integrals are presented. The results obtained with the above formulation are compared with existing analytical and experimental results.

  1. A finite-element analysis for steady and oscillatory supersonic flows around complex configurations

    NASA Technical Reports Server (NTRS)

    Morino, L.; Chen, L. T.

    1974-01-01

    The problem of small perturbation potential supersonic flow around complex configurations is considered. This problem requires the solution of an integral equation relating the values of the potential on the surface of the body to the values of the normal derivative, which is known from the small perturbation boundary conditions. The surface of the body is divided into small (hyperboloidal quadrilateral) surface elements, sigma sub i, which are described in terms of the Cartesian components of the four corner points. The values of the potential (and its normal derivative) within each element is assumed to be constant and equal to its value at the centroid of the element, and this yields a set of linear algebraic equations. The coefficients of the equation are given by source and doublet integrals over the surface elements, sigma sub i. The results obtained using the above formulation are compared with existing analytical and experimental results.

  2. Aerodynamic Shape Sensitivity Analysis and Design Optimization of Complex Configurations Using Unstructured Grids

    NASA Technical Reports Server (NTRS)

    Taylor, Arthur C., III; Newman, James C., III; Barnwell, Richard W.

    1997-01-01

    A three-dimensional unstructured grid approach to aerodynamic shape sensitivity analysis and design optimization has been developed and is extended to model geometrically complex configurations. The advantage of unstructured grids (when compared with a structured-grid approach) is their inherent ability to discretize irregularly shaped domains with greater efficiency and less effort. Hence, this approach is ideally suited for geometrically complex configurations of practical interest. In this work the nonlinear Euler equations are solved using an upwind, cell-centered, finite-volume scheme. The discrete, linearized systems which result from this scheme are solved iteratively by a preconditioned conjugate-gradient-like algorithm known as GMRES for the two-dimensional geometry and a Gauss-Seidel algorithm for the three-dimensional; similar procedures are used to solve the accompanying linear aerodynamic sensitivity equations in incremental iterative form. As shown, this particular form of the sensitivity equation makes large-scale gradient-based aerodynamic optimization possible by taking advantage of memory efficient methods to construct exact Jacobian matrix-vector products. Simple parameterization techniques are utilized for demonstrative purposes. Once the surface has been deformed, the unstructured grid is adapted by considering the mesh as a system of interconnected springs. Grid sensitivities are obtained by differentiating the surface parameterization and the grid adaptation algorithms with ADIFOR (which is an advanced automatic-differentiation software tool). To demonstrate the ability of this procedure to analyze and design complex configurations of practical interest, the sensitivity analysis and shape optimization has been performed for a two-dimensional high-lift multielement airfoil and for a three-dimensional Boeing 747-200 aircraft.

  3. On the use of symmetry in configurational analysis for the simulation of disordered solids.

    PubMed

    Mustapha, Sami; D'Arco, Philippe; De La Pierre, Marco; Noël, Yves; Ferrabone, Matteo; Dovesi, Roberto

    2013-03-13

    The starting point for a quantum mechanical investigation of disordered systems usually implies calculations on a limited subset of configurations, generated by defining either the composition of interest or a set of compositions ranging from one end member to another, within an appropriate supercell of the primitive cell of the pure compound. The way in which symmetry can be used in the identification of symmetry independent configurations (SICs) is discussed here. First, Pólya's enumeration theory is adopted to determine the number of SICs, in the case of both varying and fixed composition, for colors numbering two or higher. Then, De Bruijn's generalization is presented, which allows analysis of the case where the colors are symmetry related, e.g. spin up and down in magnetic systems. In spite of their efficiency in counting SICs, neither Pólya's nor De Bruijn's theory helps in solving the difficult problem of identifying the complete list of SICs. Representative SICs are obtained by adopting an orderly generation approach, based on lexicographic ordering, which offers the advantage of avoiding the (computationally expensive) analysis and storage of all the possible configurations. When the number of colors increases, this strategy can be combined with the surjective resolution principle, which permits the efficient generation of SICs of a problem in |R| colors starting from the ones obtained for the (|R| - 1)-colors case. The whole scheme is documented by means of three examples: the abstract case of a square with C(4v) symmetry and the real cases of the garnet and olivine mineral families.

  4. On the use of symmetry in configurational analysis for the simulation of disordered solids

    NASA Astrophysics Data System (ADS)

    Mustapha, Sami; D'Arco, Philippe; De La Pierre, Marco; Noël, Yves; Ferrabone, Matteo; Dovesi, Roberto

    2013-03-01

    The starting point for a quantum mechanical investigation of disordered systems usually implies calculations on a limited subset of configurations, generated by defining either the composition of interest or a set of compositions ranging from one end member to another, within an appropriate supercell of the primitive cell of the pure compound. The way in which symmetry can be used in the identification of symmetry independent configurations (SICs) is discussed here. First, Pólya’s enumeration theory is adopted to determine the number of SICs, in the case of both varying and fixed composition, for colors numbering two or higher. Then, De Bruijn’s generalization is presented, which allows analysis of the case where the colors are symmetry related, e.g. spin up and down in magnetic systems. In spite of their efficiency in counting SICs, neither Pólya’s nor De Bruijn’s theory helps in solving the difficult problem of identifying the complete list of SICs. Representative SICs are obtained by adopting an orderly generation approach, based on lexicographic ordering, which offers the advantage of avoiding the (computationally expensive) analysis and storage of all the possible configurations. When the number of colors increases, this strategy can be combined with the surjective resolution principle, which permits the efficient generation of SICs of a problem in |R| colors starting from the ones obtained for the (|R| - 1)-colors case. The whole scheme is documented by means of three examples: the abstract case of a square with C4v symmetry and the real cases of the garnet and olivine mineral families.

  5. Modeling of advanced divertor configuration on experimental advanced superconducting tokamak by SOLPS5.0/B2.5-Eirene

    SciTech Connect

    Si, H. Xu, G. S.; Xiao, B. J.; Luo, Z. P.; Guo, Y.; Wang, L.; Ding, R.; Guo, H. Y.

    2016-03-15

    Heat exhaust is one of the most challenging issues to be addressed for tokamak magnetic confinement fusion research. Detailed modeling with SOLPS5.0/B2.5-Eirene code package is carried out to examine an alternative advanced divertor configuration, i.e., quasi snowflake (QSF), for long pulse operation in EAST. Comparison is also made with the lower single null (LSN) divertor configuration. SOLPS predicts that the quasi snowflake configuration significantly reduces the peak heat flux at the lower divertor outer target, by a factor of 2–3, owing to the magnetic flux expansion. Furthermore, the density threshold for detachment is much lower for QSF, compared to LSN under the same upstream conditions. This indicates that QSF provides a promising tool for controlling heat flux at divertor target while maintaining a lower separatrix density, which is highly desirable for current drive, thus greatly facilitating long-pulse operation in EAST.

  6. Modeling of advanced divertor configuration on experimental advanced superconducting tokamak by SOLPS5.0/B2.5-Eirene

    NASA Astrophysics Data System (ADS)

    Si, H.; Guo, H. Y.; Xu, G. S.; Xiao, B. J.; Luo, Z. P.; Guo, Y.; Wang, L.; Ding, R.

    2016-03-01

    Heat exhaust is one of the most challenging issues to be addressed for tokamak magnetic confinement fusion research. Detailed modeling with SOLPS5.0/B2.5-Eirene code package is carried out to examine an alternative advanced divertor configuration, i.e., quasi snowflake (QSF), for long pulse operation in EAST. Comparison is also made with the lower single null (LSN) divertor configuration. SOLPS predicts that the quasi snowflake configuration significantly reduces the peak heat flux at the lower divertor outer target, by a factor of 2-3, owing to the magnetic flux expansion. Furthermore, the density threshold for detachment is much lower for QSF, compared to LSN under the same upstream conditions. This indicates that QSF provides a promising tool for controlling heat flux at divertor target while maintaining a lower separatrix density, which is highly desirable for current drive, thus greatly facilitating long-pulse operation in EAST.

  7. Women in the experimental analysis of behavior

    PubMed Central

    McSweeney, Frances K.; Swindell, Samantha

    1998-01-01

    We examined the status of women in the experimental analysis of behavior by comparing authorship by women in the Journal of the Experimental Analysis of Behavior (JEAB) to authorship by women in three similar journals. For all journals, the percentage of articles with at least one female author, the percentage of authors who are female, and the percentage of articles with a female first author increased from 1978 to 1997. However, the participation by women in JEAB lagged behind participation in the other journals on each measure. Female membership on the editorial board of JEAB also failed to increase from 1978 to 1997. Suggestions are made that may increase the participation of women in the experimental analysis of behavior. ImagesFigure 5 PMID:22478307

  8. Analysis of the structure, configuration, and sizing of Cu and Cu oxide nanoparticles generated by fs laser ablation of solid target in liquids

    NASA Astrophysics Data System (ADS)

    Santillán, J. M. J.; Videla, F. A.; Fernández van Raap, M. B.; Schinca, D. C.; Scaffardi, L. B.

    2013-04-01

    We report on the analysis of structure, configuration, and sizing of Cu and Cu oxide nanoparticles (Nps) produced by femtosecond (fs) laser ablation of solid copper target in liquids. Laser pulse energy ranged between 500 μJ and 50 μJ. Water and acetone were used to produce the colloidal suspensions. The study was performed through optical extinction spectroscopy using Mie theory to fit the full experimental spectra, considering free and bound electrons size dependent contributions to the metal dielectric function. Raman spectroscopy and AFM technique were also used to characterize the sample. Considering the possible oxidation of copper during the fabrication process, two species (Cu and Cu2O) arranged in two structures (bare core or core-shell) and in two configuration types (Cu-Cu2O or Cu2O-Cu) were considered for the fitting depending on the laser pulse energy and the surrounding media. For water at high energy, it can be observed that a Cu-Cu2O configuration fits the experimental spectra of the colloidal suspension, while for decreasing energy and below a certain threshold, a Cu2O-Cu configuration needs to be included for the optimum fit. Both species coexist for energies below 170 μJ for water. On the other hand, for acetone at high energy, optimum fit of the full spectrum suggests the presence a bimodal Cu-Cu2O core-shell Nps distribution while for decreasing energy and below a 70 μJ threshold energy value, Cu2O-Cu core-shell Nps must be included, together with the former configuration, for the fit of the full spectrum. We discuss possible reasons for the changes in the structural configuration of the core-shell Nps.

  9. Analysis of the structure, configuration, and sizing of Cu and Cu oxide nanoparticles generated by fs laser ablation of solid target in liquids

    SciTech Connect

    Santillan, J. M. J.; Videla, F. A.; Schinca, D. C.; Scaffardi, L. B.; Fernandez van Raap, M. B.

    2013-04-07

    We report on the analysis of structure, configuration, and sizing of Cu and Cu oxide nanoparticles (Nps) produced by femtosecond (fs) laser ablation of solid copper target in liquids. Laser pulse energy ranged between 500 {mu}J and 50 {mu}J. Water and acetone were used to produce the colloidal suspensions. The study was performed through optical extinction spectroscopy using Mie theory to fit the full experimental spectra, considering free and bound electrons size dependent contributions to the metal dielectric function. Raman spectroscopy and AFM technique were also used to characterize the sample. Considering the possible oxidation of copper during the fabrication process, two species (Cu and Cu{sub 2}O) arranged in two structures (bare core or core-shell) and in two configuration types (Cu-Cu{sub 2}O or Cu{sub 2}O-Cu) were considered for the fitting depending on the laser pulse energy and the surrounding media. For water at high energy, it can be observed that a Cu-Cu{sub 2}O configuration fits the experimental spectra of the colloidal suspension, while for decreasing energy and below a certain threshold, a Cu{sub 2}O-Cu configuration needs to be included for the optimum fit. Both species coexist for energies below 170 {mu}J for water. On the other hand, for acetone at high energy, optimum fit of the full spectrum suggests the presence a bimodal Cu-Cu{sub 2}O core-shell Nps distribution while for decreasing energy and below a 70 {mu}J threshold energy value, Cu{sub 2}O-Cu core-shell Nps must be included, together with the former configuration, for the fit of the full spectrum. We discuss possible reasons for the changes in the structural configuration of the core-shell Nps.

  10. Low Speed Analysis of Mission Adaptive Flaps on a High Speed Civil Transport Configuration

    NASA Technical Reports Server (NTRS)

    Lessard, Victor R.

    1999-01-01

    Thin-layer Navier-Stokes analyses were done on a high speed civil transport configuration with mission adaptive leading-edge flaps. The flow conditions simulated were Mach = 0.22 and Reynolds number of 4.27 million for angles-of-attack ranging from 0 to 18 degrees. Two turbulence closure models were used. Analyses were done exclusively with the Baldwin-Lomax turbulence model at low angle-of-attack conditions. At high angles-of-attack where considerable flow separation and vortices occurred the Spalart-Allmaras turbulence model was also considered. The effects of flow transition were studied. Predicted aerodynamic forces, moment, and pressure are compared to experimental data obtained in the 14- by 22-Foot Subsonic Tunnel at NASA Langley. The forces and moments correlated well with experimental data in terms of trends. Drag and pitching moment were consistently underpredicted. Predicted surface pressures compared well with experiment at low angles-of-attack. Above 10 angle-of-attack the pressure comparisons were not as favorable. The two turbulent models affected the pressures on the flap considerably and neither produced correct results at the high angles-of-attack.

  11. Experimental friction coefficients for bovine cartilage measured with a pin-on-disk tribometer: testing configuration and lubricant effects.

    PubMed

    Shi, Liu; Sikavitsas, Vassilios I; Striolo, Alberto

    2011-01-01

    The friction coefficient between wet articular cartilage surfaces was measured using a pin-on-disk tribometer adopting different testing configurations: cartilage-on-pin vs. alumina-on-disk (CA); cartilage-on-pin vs. cartilage-on-disk (CC); and alumina-on-pin vs. cartilage-on-disk (AC). Several substances were dissolved in the phosphate buffered saline (PBS) solution to act as lubricants: 10,000 molecular weight (MW) polyethylene glycol (PEG), 100,000 MW PEG, and chondroitin sulfate (CS), all at 100 mg/mL concentration. Scanning electron microscopy photographs of the cartilage specimens revealed limited wear due to the experiment. Conducting the experiments in PBS solutions we provide evidence according to which a commercial pin-on-disk tribometer allows us to assess different lubrication mechanisms active in cartilage. Specifically, we find that the measured friction coefficient strongly depends on the testing configuration. Our results show that the friction coefficient measured under CC and AC testing configurations remains very low as the sliding distance increases, probably because during the pin displacement the pores present in the cartilage replenish with PBS solution. Under such conditions the fluid phase supports a large load fraction for long times. By systematically altering the composition of the PBS solution we demonstrate the importance of solution viscosity in determining the measured friction coefficient. Although the friction coefficient remains low under the AC testing configuration in PBS, 100 mg/mL solutions of both CS and 100,000 MW PEG in PBS further reduce the friction coefficient by ~40%. Relating the measured friction coefficient to the Hersey number, our results are consistent with a Stribeck curve, confirming that the friction coefficient of cartilage under the AC testing configuration depends on a combination of hydrodynamic, boundary, and weep bearing lubrication mechanisms.

  12. A Novel In Vitro Sensing Configuration for Retinal Physiology Analysis of a Sub-Retinal Prosthesis

    PubMed Central

    Koo, Kyo-in; Lee, Sangmin; Yee, Jang Hee; Ryu, Sang Baek; Kim, Kyung Hwan; Goo, Yong Sook; Cho, Dong-il Dan

    2012-01-01

    This paper presents a novel sensing configuration for retinal physiology analysis, using two microelectrode arrays (MEAs). In order to investigate an optimized stimulation protocol for a sub-retinal prosthesis, retinal photoreceptor cells are stimulated, and the response of retinal ganglion cells is recorded in an in vitro environment. For photoreceptor cell stimulation, a polyimide-substrate MEA is developed, using the microelectromechanical systems (MEMS) technology. For ganglion cell response recording, a conventional glass-substrate MEA is utilized. This new sensing configuration is used to record the response of retinal ganglion cells with respect to three different stimulation methods (monopolar, bipolar, and dual-monopolar stimulation methods). Results show that the geometrical relation between the stimulation microelectrode locations and the response locations seems very low. The threshold charges of the bipolar stimulation and the monopolar stimulation are in the range of 10∼20 nC. The threshold charge of the dual-monopolar stimulation is not obvious. These results provide useful guidelines for developing a sub-retinal prosthesis. PMID:22736997

  13. Utilization of an agility assessment module in analysis and optimization of preliminary fighter configuration

    NASA Technical Reports Server (NTRS)

    Ngan, Angelen; Biezad, Daniel

    1996-01-01

    A study has been conducted to develop and to analyze a FORTRAN computer code for performing agility analysis on fighter aircraft configurations. This program is one of the modules of the NASA Ames ACSYNT (AirCraft SYNThesis) design code. The background of the agility research in the aircraft industry and a survey of a few agility metrics are discussed. The methodology, techniques, and models developed for the code are presented. The validity of the existing code was evaluated by comparing with existing flight test data. A FORTRAN program was developed for a specific metric, PM (Pointing Margin), as part of the agility module. Example trade studies using the agility module along with ACSYNT were conducted using a McDonnell Douglas F/A-18 Hornet aircraft model. Tile sensitivity of thrust loading, wing loading, and thrust vectoring on agility criteria were investigated. The module can compare the agility potential between different configurations and has capability to optimize agility performance in the preliminary design process. This research provides a new and useful design tool for analyzing fighter performance during air combat engagements in the preliminary design.

  14. Fluid-thermal analysis of aerodynamic heating over spiked blunt body configurations

    NASA Astrophysics Data System (ADS)

    Qin, Qihao; Xu, Jinglei; Guo, Shuai

    2017-03-01

    When flying at hypersonic speeds, the spiked blunt body is constantly subjected to severe aerodynamic heating. To illustrate the thermal response of different configurations and the relevant flow field variation, a loosely-coupled fluid-thermal analysis is performed in this paper. The Mesh-based parallel Code Coupling Interface (MpCCI) is adopted to implement the data exchange between the fluid solver and the thermal solver. The results indicate that increases in spike diameter and length will result in a sharp decline of the wall temperature along the spike, and the overall heat flux is remarkably reduced to less than 300 W/cm2 with the aerodome mounted at the spike tip. Moreover, the presence and evolution of small vortices within the recirculation zone are observed and proved to be induced by the stagnation effect of reattachment points on the spike. In addition, the drag coefficient of the configuration with a doubled spike length presents a maximum drop of 4.59% due to the elevated wall temperature. And the growing difference of the drag coefficient is further increased during the accelerating process.

  15. A grid-embedding transonic flow analysis computer program for wing/nacelle configurations

    NASA Technical Reports Server (NTRS)

    Atta, E. H.; Vadyak, J.

    1983-01-01

    An efficient grid-interfacing zonal algorithm was developed for computing the three-dimensional transonic flow field about wing/nacelle configurations. the algorithm uses the full-potential formulation and the AF2 approximate factorization scheme. The flow field solution is computed using a component-adaptive grid approach in which separate grids are employed for the individual components in the multi-component configuration, where each component grid is optimized for a particular geometry such as the wing or nacelle. The wing and nacelle component grids are allowed to overlap, and flow field information is transmitted from one grid to another through the overlap region using trivariate interpolation. This report represents a discussion of the computational methods used to generate both the wing and nacelle component grids, the technique used to interface the component grids, and the method used to obtain the inviscid flow solution. Computed results and correlations with experiment are presented. also presented are discussions on the organization of the wing grid generation (GRGEN3) and nacelle grid generation (NGRIDA) computer programs, the grid interface (LK) computer program, and the wing/nacelle flow solution (TWN) computer program. Descriptions of the respective subroutines, definitions of the required input parameters, a discussion on interpretation of the output, and the sample cases illustrating application of the analysis are provided for each of the four computer programs.

  16. Superposed epoch analysis of pressure and magnetic field configuration changes in the plasma sheet

    NASA Technical Reports Server (NTRS)

    Kistler, L. M.; Baumjohann, W.; Nagai, T.; Mobius, E.

    1993-01-01

    Using data from 41 substorm events in the near-Earth magnetotail, we have combined plasma, energetic ion, and magnetic field data from the AMPTE/IRM spacecraft to perform a superposed epoch analysis of changes in the total pressure and in the magnetic field configuration as a function of time relative to substorm onset. Unloading is evident in the total pressure profile; the pressure decreases by about 20 percent. Pressure changes during the growth phase are not as uniform for the different substorms as the pressure changes during the expansion phase. To study changes in the magnetic field configuration, we have determined the development of the plasma pressure profiles in z for an average of data from 15 to 19 R(E). At substorm onset, the field line dipolarization begins on the innermost field lines and then progresses to the outer field lines. The field lines map the closest to the Earth about 45 min after substorm onset, and then begin to stretch out again during the recovery phase of the substorm.

  17. Transition Documentation on a Three-Element High-Lift Configuration at High Reynolds Numbers: Analysis

    NASA Technical Reports Server (NTRS)

    Bertelrud, Arild; Anders, J. B. (Technical Monitor)

    2002-01-01

    A 2-D high-lift system experiment was conducted in August of 1996 in the Low Turbulence Pressure Tunnel at NASA Langley Research Center, Hampton, VA. The purpose of the experiment was to obtain transition measurements on a three element high-lift system for CFD code validation studies. A transition database has been created using the data from this experiment. The present report contains the analysis of the surface hot film data in terms of the transition locations on the three elements. It also includes relevant information regarding the pressure loads and distributions and the wakes behind the model to aid in the interpretation of the transition data. For some of the configurations the current pressure data has been compared with previous wind tunnel entries of the same model. The methodology used to determine the regions of transitional flow is outlined and each configuration tested has been analyzed. A discussion of interference effects, repeatability, and three-dimensional effects on the data is included.

  18. Superposed epoch analysis of pressure and magnetic field configuration changes in the plasma sheet

    NASA Technical Reports Server (NTRS)

    Kistler, L. M.; Baumjohann, W.; Nagai, T.; Mobius, E.

    1993-01-01

    Using data from 41 substorm events in the near-Earth magnetotail, we have combined plasma, energetic ion, and magnetic field data from the AMPTE/IRM spacecraft to perform a superposed epoch analysis of changes in the total pressure and in the magnetic field configuration as a function of time relative to substorm onset. Unloading is evident in the total pressure profile; the pressure decreases by about 20 percent. Pressure changes during the growth phase are not as uniform for the different substorms as the pressure changes during the expansion phase. To study changes in the magnetic field configuration, we have determined the development of the plasma pressure profiles in z for an average of data from 15 to 19 R(E). At substorm onset, the field line dipolarization begins on the innermost field lines and then progresses to the outer field lines. The field lines map the closest to the Earth about 45 min after substorm onset, and then begin to stretch out again during the recovery phase of the substorm.

  19. Engineering Analysis of Intermediate Loop and Process Heat Exchanger Requirements to Include Configuration Analysis and Materials Needs

    SciTech Connect

    T.M. Lillo; R.L. Williamson; T.R. Reed; C.B. Davis; D.M. Ginosar

    2005-09-01

    The need to locate advanced hydrogen production facilities a finite distance away from a nuclear power source necessitates the need for an intermediate heat transport loop (IHTL). This IHTL must not only efficiently transport energy over distances up to 500 meters but must also be capable of operating at high temperatures (>850oC) for many years. High temperature, long term operation raises concerns of material strength, creep resistance and general material stability (corrosion resistance). IHTL design is currently in the initial stages. Many questions remain to be answered before intelligent design can begin. The report begins to look at some of the issues surrounding the main components of an IHTL. Specifically, a stress analysis of a compact heat exchanger design under expected operating conditions is reported. Also the results of a thermal analysis performed on two ITHL pipe configurations for different heat transport fluids are presented. The configurations consist of separate hot supply and cold return legs as well as annular design in which the hot fluid is carried in an inner pipe and the cold return fluids travels in the opposite direction in the annular space around the hot pipe. The effects of insulation configurations on pipe configuration performance are also reported. Finally, a simple analysis of two different process heat exchanger designs, one a tube in shell type and the other a compact or microchannel reactor are evaluated in light of catalyst requirements. Important insights into the critical areas of research and development are gained from these analyses, guiding the direction of future areas of research.

  20. Investigation of advanced counterrotation blade configuration concepts for high speed turboprop systems. Task 5: Unsteady counterrotation ducted propfan analysis

    NASA Technical Reports Server (NTRS)

    Hall, Edward J.; Delaney, Robert A.

    1993-01-01

    The primary objective of this study was the development of a time-marching three-dimensional Euler/Navier-Stokes aerodynamic analysis to predict steady and unsteady compressible transonic flows about ducted and unducted propfan propulsion systems employing multiple blade rows. The computer codes resulting from this study are referred to as ADPAC-AOAR\\CR (Advanced Ducted Propfan Analysis Codes-Angle of Attack Coupled Row). This document is the final report describing the theoretical basis and analytical results from the ADPAC-AOACR codes developed under task 5 of NASA Contract NAS3-25270, Unsteady Counterrotating Ducted Propfan Analysis. The ADPAC-AOACR Program is based on a flexible multiple blocked grid discretization scheme permitting coupled 2-D/3-D mesh block solutions with application to a wide variety of geometries. For convenience, several standard mesh block structures are described for turbomachinery applications. Aerodynamic calculations are based on a four-stage Runge-Kutta time-marching finite volume solution technique with added numerical dissipation. Steady flow predictions are accelerated by a multigrid procedure. Numerical calculations are compared with experimental data for several test cases to demonstrate the utility of this approach for predicting the aerodynamics of modern turbomachinery configurations employing multiple blade rows.

  1. Comparisons Between Experimental Transport Analysis and Theoretical Modeling on LHD

    NASA Astrophysics Data System (ADS)

    Yamazaki, Kozo; LHD Group

    2000-10-01

    Helical plasma confinement system has a great advantage in producing steady-state high performance plasmas with built-in divertor. For the experimental analysis and predictive simulation of helical and tokamak plasmas, a simulation code TOTAL (TOroidal Transport Analysis Linkage) has been developed and is applied to the Large Helical Device (LHD, R=3.6 ~3.9m, B<3.0T ) experiments. In the LHD experiment, the global plasma confinement is ~1.5-2 times better than the well-known confinement scaling laws, and effective transport diffusivity is same order of magnitude of neoclassical ion transport with the assumption of Ti=Te. The radial electric field has been measured and roughly agrees with theoretical neoclassical values. The simple drift wave transport models are also compared with experimental values. The impurity dynamics are calculated using predictive part of the TOTAL code, and compared with the "breathing plasma" dynamics, and the role of high-Z impurity are clarified. For the analysis of high beta plasmas, local ballooning mode analysis will be added in this TOTAL code, and optimized configurations for the future MHR reactor will be searched.

  2. Analysis of three idealized reactor configurations: plate, pin, and homogeneous. [LMFBR

    SciTech Connect

    McKnight, R.D.

    1983-01-01

    Detailed Monte Carlo calculations have been performed for three distinct configurations of an idealized fast critical assembly. This idealized assembly was based on the LMFBR benchmark critical assembly ZPR-6/7. In the first configuration, the entire core was loaded with the plate unit cell of ZPR-6/7. In the second configuration, the entire core was loaded with the ZPR sodium-filled pin calandria. The actual ZPR pin calandria are loaded with mixed (U,Pu) oxide pins which closely match the composition of the ZPR-6/7 plate unit cell. For the present study, slight adjustments were made in the atom concentrations and the length of the pin calandria in order to make the core boundaries and average composition for the pin-cell configuration identical to those of the plate-cell configuration. In the third configuration, the core was homogeneous, again with identical core boundaries and average composition as the plate and pin configurations.

  3. Low-Speed Dynamic Wind Tunnel Test Analysis of a Generic 53 Degree Swept UCAV Configuration With Controls

    NASA Technical Reports Server (NTRS)

    Vicroy, Dan D.; Huber, Kerstin C.; Rohlf, Detlef; Loser, Thomas

    2014-01-01

    Several static and dynamic forced-motion wind tunnel tests have been conducted on a generic unmanned combat air vehicle (UCAV) configuration with a 53deg swept leading edge. These tests are part of an international research effort to assess and advance the state-of-art of computational fluid dynamics (CFD) methods to predict the static and dynamic stability and control characteristics for this type of configuration. This paper describes the dynamic forced motion data collected from two different models of this UCAV configuration as well as analysis of the control surface deflections on the dynamic forces and moments.

  4. Unsteady aerodynamic flow field analysis of the space shuttle configuration. Part 4: 747/orbiter aeroelastic stability

    NASA Technical Reports Server (NTRS)

    Reding, J. P.; Ericsson, L. E.

    1976-01-01

    A quasi-steady analysis of the aeroelastic stability of the lateral (antisymmetric) modes of the 747/orbiter vehicle was accomplished. The interference effect of the orbiter wake on the 747 tail furnishes an aerodynamic undamping contribution to the elastic modes. Likewise, the upstream influence of the 747 tail and aft fuselage on the orbiter beaver-tail rail fairing also is undamping. Fortunately these undamping effects cannot overpower the large damping contribution of the 747 tail and the modes are damped for the configurations analyzed. However, significant interference effects of the orbiter on the 747 tail have been observed in the pitch plane. The high response of the 747 vertical tail in the orbiter wave was also considered. Wind tunnel data points to flapping of the OMS pod wakes as the source of the wake resonance phenomenon.

  5. Laser-Induced Breakdown Spectroscopy in open-path configuration for the analysis of distant objects

    NASA Astrophysics Data System (ADS)

    Sallé, B.; Mauchien, P.; Maurice, S.

    2007-08-01

    A review of recent results on stand-off Laser-Induced Breakdown Spectroscopy (LIBS) analysis and applications is presented. Stand-off LIBS was suggested for elemental analysis of materials located in environments where any physical access was not possible but optical access could be envisaged. This review only refers to the use of the open-path LIBS configuration in which the laser beam and the returning plasma light are transmitted through the atmosphere. It does not present the results obtained with a transportation of the laser pulses to the target through an optical fiber. Open-path stand-off LIBS has mainly been used with nanosecond laser pulses for solid sample analysis at distances of tens of meters. Liquid samples have also been analyzed at distances of a few meters. The distances achievable depend on many parameters including the laser characteristics (pulse energy and power, beam divergence, spatial profile) and the optical system used to focus the pulses at a distance. A large variety of laser focusing systems have been employed for stand-off analysis comprising refracting or reflecting telescope. Efficient collection of the plasma light is also needed to obtain analytically useful signals. For stand-off LIBS analysis, a lens or a mirror is required to increase the solid angle over which the plasma light can be collected. The light collection device can be either at an angle from the laser beam path or collinear with the optical axis of the system used to focus the laser pulses on the target surface. These different configurations have been used depending on the application such as rapid sorting of metal samples, identification of material in nuclear industry, process control and monitoring in metallurgical industry, applications in future planetary missions, detection of environmental contamination or cleaning of objects of cultural heritage. Recent stand-off analyses of metal samples have been reported using femtosecond laser pulses to extend LIBS

  6. Experimental and numerical analysis of convergent nozzlex

    NASA Astrophysics Data System (ADS)

    Srinivas, G.; Rakham, Bhupal

    2017-05-01

    In this paper the main focus was given to convergent nozzle where both the experimental and numerical calculations were carried out with the support of standardized literature. In the recent years the field of air breathing and non-air breathing engine developments significantly increase its performance. To enhance the performance of both the type of engines the nozzle is the one of the component which will play a vital role, especially selecting the type of nozzle depends upon the vehicle speed requirement and aerodynamic behavior at most important in the field of propulsion. The convergent nozzle flow experimental analysis done using scaled apparatus and the similar setup was arranged artificially in the ANSYS software for doing the flow analysis across the convergent nozzle. The consistent calculation analysis are done based on the public literature survey to validate the experimental and numerical simulation results of convergent nozzle. Using these two experimental and numerical simulation approaches the best fit results will bring up to meet the design requirements. However the comparison also made to meet the reliability of the work on design criteria of convergent nozzle which can entrench in the field of propulsion applications.

  7. GAS CURTAIN EXPERIMENTAL TECHNIQUE AND ANALYSIS METHODOLOGIES

    SciTech Connect

    J. R. KAMM; ET AL

    2001-01-01

    The qualitative and quantitative relationship of numerical simulation to the physical phenomena being modeled is of paramount importance in computational physics. If the phenomena are dominated by irregular (i. e., nonsmooth or disordered) behavior, then pointwise comparisons cannot be made and statistical measures are required. The problem we consider is the gas curtain Richtmyer-Meshkov (RM) instability experiments of Rightley et al. (13), which exhibit complicated, disordered motion. We examine four spectral analysis methods for quantifying the experimental data and computed results: Fourier analysis, structure functions, fractal analysis, and continuous wavelet transforms. We investigate the applicability of these methods for quantifying the details of fluid mixing.

  8. GAS CURTAIN EXPERIMENTAL TECHNIQUE AND ANALYSIS METHODOLOGIES.

    SciTech Connect

    Kamm, J. R.; Rider, William; Rightley, P. M.; Prestridge, K. P.; Benjamin, R. F.; Vorobieff, P. V.

    2001-01-01

    The qualitative and quantitative relationship of numerical simulation to the physical phenomena being modeled is of paramount importance in computational physics. If the phenomena are dominated by irregular (i.e., nonsmooth or disordered) behavior, then pointwise comparisons cannot be made and statistical measures are required. The problem we consider is the gas curtain Richtmyer-Meshkov (RM) instability experiments of Rightley et al. [13], which exhibit complicated, disordered motion. We examine four spectral analysis methods for quantifying the experimental data and computed results: Fourier analysis, structure functions, fractal analysis, and continuous wavelet transforms. We investigate the applicability of these methods for quantifying the details of fluid mixing.

  9. The Analysis and Design of Low Boom Configurations Using CFD and Numerical Optimization Techniques

    NASA Technical Reports Server (NTRS)

    Siclari, Michael J.

    1999-01-01

    The use of computational fluid dynamics (CFD) for the analysis of sonic booms generated by aircraft has been shown to increase the accuracy and reliability of predictions. CFD takes into account important three-dimensional and nonlinear effects that are generally neglected by modified linear theory (MLT) methods. Up to the present time, CFD methods have been primarily used for analysis or prediction. Some investigators have used CFD to impact the design of low boom configurations using trial and error methods. One investigator developed a hybrid design method using a combination of Modified Linear Theory (e.g. F-functions) and CFD to provide equivalent area due to lift driven by a numerical optimizer to redesign or modify an existing configuration to achieve a shaped sonic boom signature. A three-dimensional design methodology has not yet been developed that completely uses nonlinear methods or CFD. Constrained numerical optimization techniques have existed for some time. Many of these methods use gradients to search for the minimum of a specified objective function subject to a variety of design variable bounds, linear and nonlinear constraints. Gradient based design optimization methods require the determination of the objective function gradients with respect to each of the design variables. These optimization methods are efficient and work well if the gradients can be obtained analytically. If analytical gradients are not available, the objective gradients or derivatives with respect to the design variables must be obtained numerically. To obtain numerical gradients, say, for 10 design variables, might require anywhere from 10 to 20 objective function evaluations. Typically, 5-10 global iterations of the optimizer are required to minimize the objective function. In terms of using CFD as a design optimization tool, the numerical evaluation of gradients can require anywhere from 100 to 200 CFD computations per design for only 10 design variables. If one CFD

  10. The Analysis and Design of Low Boom Configurations Using CFD and Numerical Optimization Techniques

    NASA Technical Reports Server (NTRS)

    Siclari, Michael J.

    1999-01-01

    The use of computational fluid dynamics (CFD) for the analysis of sonic booms generated by aircraft has been shown to increase the accuracy and reliability of predictions. CFD takes into account important three-dimensional and nonlinear effects that are generally neglected by modified linear theory (MLT) methods. Up to the present time, CFD methods have been primarily used for analysis or prediction. Some investigators have used CFD to impact the design of low boom configurations using trial and error methods. One investigator developed a hybrid design method using a combination of Modified Linear Theory (e.g. F-functions) and CFD to provide equivalent area due to lift driven by a numerical optimizer to redesign or modify an existing configuration to achieve a shaped sonic boom signature. A three-dimensional design methodology has not yet been developed that completely uses nonlinear methods or CFD. Constrained numerical optimization techniques have existed for some time. Many of these methods use gradients to search for the minimum of a specified objective function subject to a variety of design variable bounds, linear and nonlinear constraints. Gradient based design optimization methods require the determination of the objective function gradients with respect to each of the design variables. These optimization methods are efficient and work well if the gradients can be obtained analytically. If analytical gradients are not available, the objective gradients or derivatives with respect to the design variables must be obtained numerically. To obtain numerical gradients, say, for 10 design variables, might require anywhere from 10 to 20 objective function evaluations. Typically, 5-10 global iterations of the optimizer are required to minimize the objective function. In terms of using CFD as a design optimization tool, the numerical evaluation of gradients can require anywhere from 100 to 200 CFD computations per design for only 10 design variables. If one CFD

  11. Self-mixing grating interferometer: theoretical analysis and experimental observations

    NASA Astrophysics Data System (ADS)

    Guo, Dongmei; Wang, Ming; Hao, Hui

    2016-08-01

    By combining self-mixing interferometer (SMI) and grating interferometer (GI), a self-mixing grating interferometer (SMGI) is proposed in this paper. Self-mixing interference occurs when light emitted from a laser diode is diffracted by the doublediffraction system and re-enters the laser active cavity, thus generating a modulation of both the amplitude and the frequency of the lasing field. Theoretical analysis and experimental observations show that the SMGI has the same phase sensitivity as that of the conventional GI and the direction of the phase movement can be obtained from inclination of the interference signal. Compared with the traditional SMI, the phase change of interference signal in SMGI is independent of laser wavelength, providing better immunity against environmental disturbances such as temperature, pressure, and humidity variation. Compared with the traditional GI, the SMGI provides a potential displacement sensor with directional discrimination and quite compact configuration.

  12. Analysis and experimental studies of the control of hang gliders

    NASA Technical Reports Server (NTRS)

    Phillips, W. H.

    1974-01-01

    A theoretical analysis of the longitudinal and lateral characteristics of hang gliders in straight flight, pullups, and turns is presented. Some examples of the characteristics of a straight-wing configuration and a Rogallo-wing configuration are given. A means for improving the control of hang gliders while retaining the same basic control feel is proposed.

  13. CFD analysis on gas distribution for different scrubber redirection configurations in sump cut.

    PubMed

    Zheng, Y; Organiscak, J A; Zhou, L; Beck, T W; Rider, J P

    2015-01-01

    The National Institute for Occupational Safety and Health's Office of Mine Safety and Health Research recently developed a series of models using computational fluid dynamics (CFD) to study the gas distribution around a continuous mining machine with various fan-powered flooded bed scrubber discharge configurations. CFD models using Species Transport Model without reactions in FLUENT were constructed to evaluate the redirection of scrubber discharge toward the mining face rather than behind the return curtain. The following scenarios are considered in this study: 100 percent of the discharge redirected back toward the face on the off-curtain side of the continuous miner; 100 percent of the discharge redirected back toward the face, but divided equally to both sides of the machine; and 15 percent of the discharge redirected toward the face on the off-curtain side of the machine, with 85 percent directed into the return. These models were compared against a model with a conventional scrubber discharge, where air is directed away from the face into the return. The CFD models were calibrated and validated based on experimental data and accurately predicted sulfur hexafluoride (SF6) gas levels at four gas monitoring locations. One additional prediction model was simulated to consider a different scrubber discharge angle for the 100 percent redirected, equally divided case. These models identified relatively high gassy areas around the continuous miner, which may not warrant their use in coal mines with medium to high methane liberation rates. This paper describes the methodology used to develop the CFD models, and the validation of the models based on experimental data.

  14. CFD analysis on gas distribution for different scrubber redirection configurations in sump cut

    PubMed Central

    Zheng, Y.; Organiscak, J.A.; Zhou, L.; Beck, T.W.; Rider, J.P.

    2016-01-01

    The National Institute for Occupational Safety and Health’s Office of Mine Safety and Health Research recently developed a series of models using computational fluid dynamics (CFD) to study the gas distribution around a continuous mining machine with various fan-powered flooded bed scrubber discharge configurations. CFD models using Species Transport Model without reactions in FLUENT were constructed to evaluate the redirection of scrubber discharge toward the mining face rather than behind the return curtain. The following scenarios are considered in this study: 100 percent of the discharge redirected back toward the face on the off-curtain side of the continuous miner; 100 percent of the discharge redirected back toward the face, but divided equally to both sides of the machine; and 15 percent of the discharge redirected toward the face on the off-curtain side of the machine, with 85 percent directed into the return. These models were compared against a model with a conventional scrubber discharge, where air is directed away from the face into the return. The CFD models were calibrated and validated based on experimental data and accurately predicted sulfur hexafluoride (SF6) gas levels at four gas monitoring locations. One additional prediction model was simulated to consider a different scrubber discharge angle for the 100 percent redirected, equally divided case. These models identified relatively high gassy areas around the continuous miner, which may not warrant their use in coal mines with medium to high methane liberation rates. This paper describes the methodology used to develop the CFD models, and the validation of the models based on experimental data. PMID:28018125

  15. Exploratory studies of the cruise performance of upper surface blown configurations. Experimental program: Test facilities, model design instrumentation, and lowspeed, high-lift tests

    NASA Technical Reports Server (NTRS)

    Braden, J. A.; Hancock, J. P.; Burdges, K. P.; Hackett, J. E.

    1980-01-01

    The model hardware, test facilities and instrumentation utilized in an experimental study of upper surface blown configurations at cruise is described. The high speed (subsonic) experimental work, studying the aerodynamic effects of wing nacelle geometric variations, was conducted around semispan model configurations composed of diversified, interchangeable components. Power simulation was provided by high pressure air ducted through closed forebody nacelles. Nozzle geometry was varied across size, exit aspect ratio, exit position and boattail angle. Three dimensional force and two dimensional pressure measurements were obtained at cruise Mach numbers from 0.5 to 0.8 and at nozzle pressure ratios up to about 3.0. The experimental investigation was supported by an analytical synthesis of the system using a vortex lattice representation with first order power effects. Results are also presented from a compatibility study in which a short haul transport is designed on the basis of the aerodynamic findings in the experimental study as well as acoustical data obtained in a concurrent program. High lift test data are used to substantiate the projected performance of the selected transport design.

  16. Neutronic analysis of three-element core configurations for the Advanced Neutron Source Reactor

    SciTech Connect

    Gehin, J.C.

    1995-08-01

    Calculations of several important neutronic parameters have been performed for ten different three-element configurations considered for the Advanced Neutron Source (ANS) Reactor. Six of these configurations (labeled ST, SB, MT, MB, LT, and LB) are there result of the permutations of the same three elements. Two configurations (ST- MOD and SB-MOD) have the same element configuration as their base core design (ST and SB) but have slightly different element dimensions, and two configurations (ST-OL1 and ST-OL2) have two overlapping elements to increase the neutron fluxes in the reflector. For each configuration, in addition to the conceptual two-element design, fuel-cycle calculations were performed with calculations required to obtain unperturbed fluxes. The element power densities, peak thermal neutron flux as a function of position throughout the cycle, fast flux, fast-to-thermal flux ratios, irradiation and production region fluxes, and control rod worth curves were determined. The effective multiplication factor for each fuel element criticality. A comparison shows that the ST core configurations have the best overall performance, and the fully overlapping core configuration ST-OL2 has the best performance by a large margin. Therefore, on the basis of the neutronics results, the fully overlapping configuration is recommended for further consideration in using a three-element ANS reactor core. Other considerations such as thermal-hydraulics, safety, and engineering that are not directly related to the core neutronic performance must be weighed before a final design is chosen.

  17. A Summary of Revisions Applied to a Turbulence Response Analysis Method for Flexible Aircraft Configurations

    NASA Technical Reports Server (NTRS)

    Funk, Christie J.; Perry, Boyd, III; Silva, Walter A.; Newman, Brett

    2014-01-01

    A software program and associated methodology to study gust loading on aircraft exists for a classification of geometrically simplified flexible configurations. This program consists of a simple aircraft response model with two rigid and three flexible symmetric degrees-of - freedom and allows for the calculation of various airplane responses due to a discrete one-minus- cosine gust as well as continuous turbulence. Simplifications, assumptions, and opportunities for potential improvements pertaining to the existing software program are first identified, then a revised version of the original software tool is developed with improved methodology to include more complex geometries, additional excitation cases, and additional output data so as to provide a more useful and precise tool for gust load analysis. In order to improve the original software program to enhance usefulness, a wing control surface and horizontal tail control surface is added, an extended application of the discrete one-minus-cosine gust input is employed, a supplemental continuous turbulence spectrum is implemented, and a capability to animate the total vehicle deformation response to gust inputs is included. These revisions and enhancements are implemented and an analysis of the results is used to validate the modifications.

  18. An Overview of Modifications Applied to a Turbulence Response Analysis Method for Flexible Aircraft Configurations

    NASA Technical Reports Server (NTRS)

    Funk, Christie J.

    2013-01-01

    A software program and associated methodology to study gust loading on aircraft exists for a classification of geometrically simplified flexible configurations. This program consists of a simple aircraft response model with two rigid and three flexible symmetric degrees of freedom and allows for the calculation of various airplane responses due to a discrete one-minus-cosine gust as well as continuous turbulence. Simplifications, assumptions, and opportunities for potential improvements pertaining to the existing software program are first identified, then a revised version of the original software tool is developed with improved methodology to include more complex geometries, additional excitation cases, and output data so as to provide a more useful and accurate tool for gust load analysis. Revisions are made in the categories of aircraft geometry, computation of aerodynamic forces and moments, and implementation of horizontal tail mode shapes. In order to improve the original software program to enhance usefulness, a wing control surface and horizontal tail control surface is added, an extended application of the discrete one-minus-cosine gust input is employed, a supplemental continuous turbulence spectrum is implemented, and a capability to animate the total vehicle deformation response to gust inputs in included. These revisions and enhancements are implemented and an analysis of the results is used to validate the modifications.

  19. Preliminary Computational Analysis of the (HIRENASD) Configuration in Preparation for the Aeroelastic Prediction Workshop

    NASA Technical Reports Server (NTRS)

    Chwalowski, Pawel; Florance, Jennifer P.; Heeg, Jennifer; Wieseman, Carol D.; Perry, Boyd P.

    2011-01-01

    This paper presents preliminary computational aeroelastic analysis results generated in preparation for the first Aeroelastic Prediction Workshop (AePW). These results were produced using FUN3D software developed at NASA Langley and are compared against the experimental data generated during the HIgh REynolds Number Aero- Structural Dynamics (HIRENASD) Project. The HIRENASD wind-tunnel model was tested in the European Transonic Windtunnel in 2006 by Aachen University0s Department of Mechanics with funding from the German Research Foundation. The computational effort discussed here was performed (1) to obtain a preliminary assessment of the ability of the FUN3D code to accurately compute physical quantities experimentally measured on the HIRENASD model and (2) to translate the lessons learned from the FUN3D analysis of HIRENASD into a set of initial guidelines for the first AePW, which includes test cases for the HIRENASD model and its experimental data set. This paper compares the computational and experimental results obtained at Mach 0.8 for a Reynolds number of 7 million based on chord, corresponding to the HIRENASD test conditions No. 132 and No. 159. Aerodynamic loads and static aeroelastic displacements are compared at two levels of the grid resolution. Harmonic perturbation numerical results are compared with the experimental data using the magnitude and phase relationship between pressure coefficients and displacement. A dynamic aeroelastic numerical calculation is presented at one wind-tunnel condition in the form of the time history of the generalized displacements. Additional FUN3D validation results are also presented for the AGARD 445.6 wing data set. This wing was tested in the Transonic Dynamics Tunnel and is commonly used in the preliminary benchmarking of computational aeroelastic software.

  20. Analysis and moving base simulation of transition configuration management aspects of a powered lift aircraft

    NASA Technical Reports Server (NTRS)

    Johnson, W. A.; Craig, S. J.; Ashkenas, I. L.

    1973-01-01

    A study aimed at the implementation of a configuration management flight control system is reported. The system is designed to take the guesswork out of, and improve the operational safety of, transition flight in the region from cruise to STOL. Potential improvements in the trim configuration management aspects of the transition process are described.

  1. Analysis of Plume Effects on Sonic Boom Signature for Isolated Nozzle Configurations

    NASA Technical Reports Server (NTRS)

    Castner, Raymond S.

    2008-01-01

    Computational fluid dynamics (CFD) analysis has been performed to study the plume effects on sonic boom signature for isolated nozzle configurations. The objectives of these analyses were to provide comparison to past work using modern CFD analysis tools, to investigate the differences of high aspect ratio nozzles to circular (axisymmetric) nozzles, and to report the effects of underexpanded nozzle operation on boom signature. CFD analysis was used to address the plume effects on sonic boom signature from a baseline exhaust nozzle. Near-field pressure signatures were collected for nozzle pressure ratios (NPRs) between 6 and 10. A computer code was used to extrapolate these signatures to a ground-observed sonic boom N-wave. Trends show that there is a reduction in sonic boom N-wave signature as NPR is increased from 6 to 10. The performance curve for this supersonic nozzle is flat, so there is not a significant loss in thrust coefficient as the NPR is increased. As a result, this benefit could be realized without significant loss of performance. Analyses were also collected for a high aspect ratio nozzle based on the baseline design for comparison. Pressure signatures were collected for nozzle pressure ratios from 8 to 12. Signatures were nearly twice as strong for the two-dimensional case, and trends also show a reduction in sonic boom signature as NPR is increased from 8 to 12. As low boom designs are developed and improved, there will be a need for understanding the interaction between the aircraft boat tail shocks and the exhaust nozzle plume. These CFD analyses will provide a baseline study for future analysis efforts.

  2. Biosynthesis, isolation, and NMR analysis of leukotriene A epoxides: substrate chirality as a determinant of the cis or trans epoxide configuration[S

    PubMed Central

    Jin, Jing; Zheng, Yuxiang; Boeglin, William E.; Brash, Alan R.

    2013-01-01

    Leukotriene (LT)A4 and closely related allylic epoxides are pivotal intermediates in lipoxygenase (LOX) pathways to bioactive lipid mediators that include the leukotrienes, lipoxins, eoxins, resolvins, and protectins. Although the structure and stereochemistry of the 5-LOX product LTA4 is established through comparison to synthetic standards, this is the exception, and none of these highly unstable epoxides has been analyzed in detail from enzymatic synthesis. Understanding of the mechanistic basis of the cis or trans epoxide configuration is also limited. To address these issues, we developed methods involving biphasic reaction conditions for the LOX-catalyzed synthesis of LTA epoxides in quantities sufficient for NMR analysis. As proof of concept, human 15-LOX-1 was shown to convert 15S-hydroperoxy-eicosatetraenoic acid (15S-HPETE) to the LTA analog 14S,15S-trans-epoxy-eicosa-5Z,8Z,10E,12E-tetraenoate, confirming the proposed structure of eoxin A4. Using this methodology we then showed that recombinant Arabidopsis AtLOX1, an arachidonate 5-LOX, converts 5S-HPETE to the trans epoxide LTA4 and converts 5R-HPETE to the cis epoxide 5-epi-LTA4, establishing substrate chirality as a determinant of the cis or trans epoxide configuration. The results are reconciled with a mechanism based on a dual role of the LOX nonheme iron in LTA epoxide biosynthesis, providing a rational basis for understanding the stereochemistry of LTA epoxide intermediates in LOX-catalyzed transformations. PMID:23242647

  3. Determining potential 30/20 GHz domestic satellite system concepts and establishment of a suitable experimental configuration

    NASA Technical Reports Server (NTRS)

    Stevens, G. H.; Anzic, G.

    1979-01-01

    Issues and results in a NASA study of the potential concepts and markets for a multibeam 30/20 GHz domestic satellite system in the 1990s are presented. Issues considered include the reduction of signal attenuation due to rain, beam-beam interference isolation in the multibeam system, the method of access/modulation (FDMA, TDMA or hybrid) and the market for reduced reliability and wideband services. A hypothetical demonstration payload configuration which would attempt to resolve these issues is illustrated. The communications payload would employ a system of seven contiguous coverage spots in order to demonstrate a typical cell in a contiguous beam system having extensive frequency re-use, as in a direct-to-user system, and a single spot, typical of a trunking system, to determine signal isolation. The payload could be carried on several existing buses and is illustrated on an MMS bus.

  4. Scale-4 Analysis of Pressurized Water Reactor Critical Configurations: Volume 4-Three Mile Island Unit 1 Cycle 5

    SciTech Connect

    DeHart, M.D.

    1995-01-01

    The requirements of ANSI/ANS-8.1 specify that calculational methods for away-from-reactor criticality safety analyses be validated against experimental measurements. If credit is to be taken for the reduced reactivity of burned or spent fuel relative to its original ''fresh'' composition, it is necessary to benchmark computational methods used in determining such reactivity worth against spent fuel reactivity measurements. This report summarizes a portion of the ongoing effort to benchmark away-from-reactor criticality analysis methods using relevant and well-documented critical configurations from commercial pressurized water reactors. The analysis methodology utilized for all calculations in this report is based on the modules and data associated with the SCALE-4 code system. Isotopic densities for spent fuel assemblies in the core were calculated using the SCALE-4 SAS2H analytical sequence. The sources of data and the procedures for deriving SAS2H input parameters are described in detail. The SNIKR code family was used to extract the necessary isotopic densities from SAS2H results and to provide the data in the format required for SCALE criticality analysis modules. The CSASN analytical sequence in SCALE-4 was used to perform resonance processing of cross sections. The KENO V.a module of SCALE-4 was used to calculate the effective multiplication factor (k{sub eff}) for the critical configuration. The SCALE-4 27-group burnup library containing ENDF/B-IV (actinides) and ENDF/B-V (fission products) data was used for all calculations. This volume of the report documents a reactor critical calculation for GPU Nuclear Corporation's Three Mile Island Unit 1 (TMI-1) during hot, zero-power startup testing for the beginning of cycle 5. This unit and cycle were selected because of their relevance in spent fuel benchmark applications: (1) cycle 5 startup occurred after an especially long downtime of 6.6 years; and (2) the core consisted primarily (75%) of burned fuel, with

  5. IR, VCD, 1H and 13C NMR experimental and theoretical studies of a natural guaianolide: Unambiguous determination of its absolute configuration

    NASA Astrophysics Data System (ADS)

    Bercion, Sylvie; Buffeteau, Thierry; Lespade, Laure; Martin, Marie-Anna Couppe deK.

    2006-06-01

    7,10-Epoxy -1,5-guaia-3, 11-dien-8, 12-olide has been isolated from dried leaves of Hedyosmum arborescens Swartz. The structure, vibrational frequencies, infrared and VCD intensities, NMR 1H and 13C spectra have been calculated by the density functional theory (DFT) method at the B3LYP/6-31+G(d,p) levels for four stereoisomers of this natural guaianolide. This study shows that the comparison of the experimental and calculated 1H and 13C NMR spectra allows the determination of the most favorable diastereoisomers but is not sufficient to access to the absolute configuration of the 7,10-epoxy guaianolide since the two remaining enantiomers possess the same NMR spectra. The absolute configuration of this natural compound can be unambiguously established only by the comparison of the calculated and experimental VCD spectra. Indeed, a very good agreement between experimental and theoretical VCD spectra was obtained in the mid-infrared range for the 7 S, 10 R-epoxy-1 R,5 R-guaia-3,11-dien-8 S,12-olide stereoisomer.

  6. Analysis and Inverse Design of the HSR Arrow Wing Configuration with Fuselage, Wing, and Flow Through Nacelles

    NASA Technical Reports Server (NTRS)

    Krist, Steven E.; Bauer, Steven X. S.

    1999-01-01

    The design process for developing the natural flow wing design on the HSR arrow wing configuration utilized several design tools and analysis methods. Initial fuselage/wing designs were generated with inviscid analysis and optimization methods in conjunction with the natural flow wing design philosophy. A number of designs were generated, satisfying different system constraints. Of the three natural flow wing designs developed, the NFWAc2 configuration is the design which satisfies the constraints utilized by McDonnell Douglas Aerospace (MDA) in developing a series of optimized configurations; a wind tunnel model of the MDA designed OPT5 configuration was constructed and tested. The present paper is concerned with the viscous analysis and inverse design of the arrow wing configurations, including the effects of the installed diverters/nacelles. Analyses were conducted with OVERFLOW, a Navier-Stokes flow solver for overset grids. Inverse designs were conducted with OVERDISC, which couples OVERFLOW with the CDISC inverse design method. An initial system of overset grids was generated for the OPT5 configuration with installed diverters/nacelles. An automated regridding process was then developed to use the OPT5 component grids to create grids for the natural flow wing designs. The inverse design process was initiated using the NFWAc2 configuration as a starting point, eventually culminating in the NFWAc4 design-for which a wind tunnel model was constructed. Due to the time constraints on the design effort, initial analyses and designs were conducted with a fairly coarse grid; subsequent analyses have been conducted on a refined system of grids. Comparisons of the computational results to experiment are provided at the end of this paper.

  7. Analysis and Inverse Design of the HSR Arrow Wing Configuration with Fuselage, Wing, and Flow Through Nacelles

    NASA Technical Reports Server (NTRS)

    Krist, Steven E.; Bauer, Steven X. S.

    1999-01-01

    The design process for developing the natural flow wing design on the HSR arrow wing configuration utilized several design tools and analysis methods. Initial fuselage/wing designs were generated with inviscid analysis and optimization methods in conjunction with the natural flow wing design philosophy. A number of designs were generated, satisfying different system constraints. Of the three natural flow wing designs developed, the NFWAc2 configuration is the design which satisfies the constraints utilized by McDonnell Douglas Aerospace (MDA) in developing a series of optimized configurations; a wind tunnel model of the MDA designed OPT5 configuration was constructed and tested. The present paper is concerned with the viscous analysis and inverse design of the arrow wing configurations, including the effects of the installed diverters/nacelles. Analyses were conducted with OVERFLOW, a Navier-Stokes flow solver for overset grids. Inverse designs were conducted with OVERDISC, which couples OVERFLOW with the CDISC inverse design method. An initial system of overset grids was generated for the OPT5 configuration with installed diverters/nacelles. An automated regridding process was then developed to use the OPT5 component grids to create grids for the natural flow wing designs. The inverse design process was initiated using the NFWAc2 configuration as a starting point, eventually culminating in the NFWAc4 design-for which a wind tunnel model was constructed. Due to the time constraints on the design effort, initial analyses and designs were conducted with a fairly coarse grid; subsequent analyses have been conducted on a refined system of grids. Comparisons of the computational results to experiment are provided at the end of this paper.

  8. Scale-4 analysis of pressurized water reactor critical configurations: Volume 5, North Anna Unit 1 Cycle 5

    SciTech Connect

    Bowman, S.M.; Suto, T. |

    1996-10-01

    ANSI/ANS 8.1 requires that calculational methods for away-from- reactor (AFR) criticality safety analyses be validated against experiment. This report summarizes part of the ongoing effort to benchmark AFR criticality analysis methods using selected critical configurations from commercial PWRs. Codes and data in the SCALE-4 code system were used. This volume documents the SCALE system analysis of one reactor critical configuration for North Anna Unit 1 Cycle 5. The KENO V.a criticality calculations for the North Anna 1 Cycle 5 beginning-of-cycle model yielded a value for k{sub eff} of 1. 0040{+-}0.0005.

  9. Navier-Stokes Analysis of a High Wing Transport High-Lift Configuration with Externally Blown Flaps

    NASA Technical Reports Server (NTRS)

    Slotnick, Jeffrey P.; An, Michael Y.; Mysko, Stephen J.; Yeh, David T.; Rogers, Stuart E.; Roth, Karlin; Baker, M.David; Nash, S.

    2000-01-01

    Insights and lessons learned from the aerodynamic analysis of the High Wing Transport (HWT) high-lift configuration are presented. Three-dimensional Navier-Stokes CFD simulations using the OVERFLOW flow solver are compared with high Reynolds test data obtained in the NASA Ames 12 Foot Pressure Wind Tunnel (PWT) facility. Computational analysis of the baseline HWT high-lift configuration with and without Externally Blown Flap (EBF) jet effects is highlighted. Several additional aerodynamic investigations, such as nacelle strake effectiveness and wake vortex studies, are presented. Technical capabilities and shortcomings of the computational method are discussed and summarized.

  10. Pressure loads and aerodynamic force information for the -89A space shuttle orbiter configuration, volume 2. [for structural strength analysis

    NASA Technical Reports Server (NTRS)

    Mennell, R. C.

    1973-01-01

    Experimental aerodynamic investigations were conducted on an 0.0405 scale representation of the Rockwell -89A Light Weight Space Shuttle Orbiter. The test purpose was to obtain pressure loads data in the presence of the ground for orbiter structural strength analysis. Aerodynamic force data was also recorded to allow correlation with all pressure loads information. Angles of attack from minus 3 deg to 18 deg and angles of sideslip of 0 deg, plus or minus 50 deg, and plus or minus 10 deg were tested in the presence of the NAAL ground plane. Static pressure bugs were used to obtain a pressure loads survey of the basic configuration, elevon deflections of 5 deg, 10 deg, 15 deg, and minus 20 deg and a rudder deflection of minus 15 deg, at a tunnel dynamic pressure of 40 psi. The test procedure was to locate a maximum of 30 static pressure bugs on the model surface at various locations calculated to prevent aerodynamic and physical interference. Then by various combinations of location the pressure bugs output was to define a complete pressure survey for the fuselages, wing, vertical tail, and main landing gear door.

  11. Identifying the causes of water crises: A configurational frequency analysis of 22 basins world wide

    NASA Astrophysics Data System (ADS)

    Srinivasan, V.; Gorelick, S.; Lambin, E.; Rozelle, S.; Thompson, B.

    2010-12-01

    Freshwater "scarcity" has been identified as being a major problem world-wide, but it is surprisingly hard to assess if water is truly scarce at a global or even regional scale. Most empirical water research remains location specific. Characterizing water problems, transferring lessons across regions, to develop a synthesized global view of water issues remains a challenge. In this study we attempt a systematic understanding of water problems across regions. We compared case studies of basins across different regions of the world using configurational frequency analysis. Because water crises are multi-symptom and multi-causal, a major challenge was to categorize water problems so as to make comparisons across cases meaningful. In this study, we focused strictly on water unsustainability, viz. the inability to sustain current levels of the anthropogenic (drinking water, food, power, livelihood) and natural (aquatic species, wetlands) into the future. For each case, the causes of three outcome variables, groundwater declines, surface water declines and aquatic ecosystem declines, were classified and coded. We conducted a meta-analysis in which clusters of peer-reviewed papers by interdisciplinary teams were considered to ensure that the results were not biased towards factors privileged by any one discipline. Based on our final sample of 22 case study river basins, some clear patterns emerged. The meta-analysis suggests that water resources managers have long overemphasized the factors governing supply of water resources and while insufficient attention has been paid to the factors driving demand. Overall, uncontrolled increase in demand was twice as frequent as declines in availability due to climate change or decreased recharge. Moreover, groundwater and surface water declines showed distinct causal pathways. Uncontrolled increases in demand due to lack of credible enforcement were a key factor driving groundwater declines; while increased upstream abstractions

  12. Computational and experimental analysis of DNA shuffling

    PubMed Central

    Maheshri, Narendra; Schaffer, David V.

    2003-01-01

    We describe a computational model of DNA shuffling based on the thermodynamics and kinetics of this process. The model independently tracks a representative ensemble of DNA molecules and records their states at every stage of a shuffling reaction. These data can subsequently be analyzed to yield information on any relevant metric, including reassembly efficiency, crossover number, type and distribution, and DNA sequence length distributions. The predictive ability of the model was validated by comparison to three independent sets of experimental data, and analysis of the simulation results led to several unique insights into the DNA shuffling process. We examine a tradeoff between crossover frequency and reassembly efficiency and illustrate the effects of experimental parameters on this relationship. Furthermore, we discuss conditions that promote the formation of useless “junk” DNA sequences or multimeric sequences containing multiple copies of the reassembled product. This model will therefore aid in the design of optimal shuffling reaction conditions. PMID:12626764

  13. Analysis of the characteristics of slot design affecting resistance to sliding during active archwire configurations

    PubMed Central

    2013-01-01

    Background During orthodontic treatment, a low resistance to slide (RS) is desirable when sliding mechanics are used. Many studies showed that several variables affect the RS at the bracket-wire interface; among these, the design of the bracket slot has not been deeply investigated yet. This study aimed to clarify the effect of different slot designs on the RS expressed by five types of low-friction brackets in vertical and horizontal active configurations of the wire. Methods Five low-friction brackets (Damon SL II, Ormco, Orange, CA, USA; In-Ovation, GAC International, Bohemia, NY, USA; Quick, Forestadent, Pforzheim, Germany; Time 2, AO, Sheboygan, WI, USA; Synergy, RMO, Denver, CO, USA) coupled with an 0.014-in NiTi thermal wire (Therma-Lite, AO) were tested in two three-bracket experimental models simulating vertical and horizontal bracket displacements. A custom-made machine was used to measure frictional resistance with tests repeated on ten occasions for each bracket-wire combination. Design characteristics such as the mesio-distal slot width, slot depth, and presence of chamfered edges at the extremities of the slot were evaluated on SEM images (SUPRA, Carl Zeiss, Oberkochen, Germany) and analyzed in relation to the data of RS recorded. Results Time 2 was found to show the higher frictional forces (1.50 and 1.35 N) in both experimental models (p < 0.05), while Quick and Synergy brackets showed the lower frictional values in the vertical (0.66 N) and in the horizontal (0.68 N) bracket displacements, respectively. With vertically displaced brackets, the increased mesio-distal slot width and the presence of clear angle at mesial and distal slot edges increase the values of RS. With brackets horizontally displaced, the RS expressed by the wire is influenced simultaneously by the depth of the slot, the mesio-distal slot width, and the presence of clear angle at the extremities of the slot base, the clip, or the slide. Conclusion In order to select the proper low

  14. Detection and Analysis of X Ray Emission from the Princeton-Field-Reversed Configuration (PFRC-2)

    NASA Astrophysics Data System (ADS)

    Bosh, Alexandra; Swanson, Charles; Jandovitz, Peter; Cohen, Samuel

    2016-10-01

    The PFRC is an odd-parity rotating-magnetic-field-driven field-reversed-configuration magnetic confinement experiment. Studying X rays produced via electron Bremsstrahlung with neutral particles is crucial to the further understanding of the energy and particle confinement of the PFRC. The data on the x rays are collected using a detector system comprised of two, spatially scannable Amptek XR-100 CR detectors and a Amptek XR-100 SDD detector that view the plasma column at two axial locations, one in the divertor and one near the axial midplane. These provide X-ray energy and arrival-time information. (Data analysis requires measurement of each detector's efficiency, a parameter that is modified by window transmission. Detector calibrations were performed with a custom-made X-ray tube that impinged 1-microamp 1-5 kV electron beams onto a carbon target.) From the analyzed data, the average electron energy, effective temperature, and electron density can be extracted. Spatial scans then allow the FRC's internal energy to be measured. We present recent measurements of the Bremsstrahlung spectrum from 0.8 to 6 keV and the inferred electron temperature in the PFRC device as functions of heating power, magnetic field and fill gas pressure. This work was supported, in part, by DOE Contract Number DE-AC02-09CH11466.

  15. CFD Analysis and Design of Detailed Target Configurations for an Accelerator-Driven Subcritical System

    SciTech Connect

    Kraus, Adam; Merzari, Elia; Sofu, Tanju; Zhong, Zhaopeng; Gohar, Yousry

    2016-08-01

    High-fidelity analysis has been utilized in the design of beam target options for an accelerator driven subcritical system. Designs featuring stacks of plates with square cross section have been investigated for both tungsten and uranium target materials. The presented work includes the first thermal-hydraulic simulations of the full, detailed target geometry. The innovative target cooling manifold design features many regions with complex flow features, including 90 bends and merging jets, which necessitate three-dimensional fluid simulations. These were performed using the commercial computational fluid dynamics code STAR-CCM+. Conjugate heat transfer was modeled between the plates, cladding, manifold structure, and fluid. Steady-state simulations were performed but lacked good residual convergence. Unsteady simulations were then performed, which converged well and demonstrated that flow instability existed in the lower portion of the manifold. It was established that the flow instability had little effect on the peak plate temperatures, which were well below the melting point. The estimated plate surface temperatures and target region pressure were shown to provide sufficient margin to subcooled boiling for standard operating conditions. This demonstrated the safety of both potential target configurations during normal operation.

  16. Space transportation booster engine configuration study. Volume 2: Design definition document and environmental analysis

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The objective of the Space Transportation Booster Engine (STBE) Configuration Study is to contribute to the Advanced Launch System (ALS) development effort by providing highly reliable, low cost booster engine concepts for both expendable and reusable rocket engines. The objectives of the space Transportation Booster Engine (STBE) Configuration Study were: (1) to identify engine configurations which enhance vehicle performance and provide operational flexibility at low cost, and (2) to explore innovative approaches to the follow-on Full-Scale Development (FSD) phase for the STBE.

  17. Tests of strain analysis by experimental deformation

    NASA Astrophysics Data System (ADS)

    Borradaile, G. J.; McArthur, J.

    1991-01-01

    The linearisation method and Robin's method of strain analysis of granular materials yield accurate strain estimates for a variety of materials deformed experimentally in pure shear. The breakdown of continuum behaviour at high pore fluid pressures causes the methods to overestimate the strain because they do not take added rigid-body rotation into account. Both methods tolerate some variation in initial shape ratio and some degree of initial preferred orientation at modest strains. Results of tests on polymict sandstone indicate that the lower than average ductility of competent clasts may be balanced against an unfavourable degree of preferred orientation to yield an improved strain estimate.

  18. Sensitivity analysis and optimization of the COSMO-CLM configuration over Italy

    NASA Astrophysics Data System (ADS)

    Montesarchio, M.; Manzi, M.; Mercogliano, P.; Bucchignani, E.

    2012-12-01

    The aim of this work is to analyze the sensitivity of the precipitation and the 2-meters mean temperature in response to the variation of some physical, numerical and tuning parameters in COSMO-CLM, a non-hydrostatic model for the simulation of atmospheric processes. The model has been developed by the DWD-Germany for weather forecast services; successively, the model has been updated by the CLM-Community, in order to develop also climatic applications. It is the only documented numerical model system in Europe designed for spatial resolutions down to 1km with a range of applicability encompassing operational numerical weather prediction, regional climate modelling the dispersion of trace gases and aerosol and idealised studies and applicable in all regions of the world for a wide range of available climate simulations from global climate and NWP models. The main goal is to adjust the configuration of COSMO-CLM over Italy in order to better reproduce the climate of the last thirty years of the XX century. Moreover, the crucial point of this analysis is the reduction of the precipitation bias on Alps and the understanding and improvement of the strong local temperature bias registered in specific areas such as Po Valley. In the present work, a precise sensitivity analysis has been performed on the domain 4.7-16.7°E; 40.8-48.3°N, considering the time period 1996-2000. The choice of this domain is mainly due to the availability of different observational dataset to perform the result validation: E-OBS (a European land only daily high resolution gridded dataset for precipitation and mean surface temperature covering the period 1960-2006), ETH (Alpine Precipitation Analyses from High-Resolution Rain-Gauge Observations) and ARPA EMR (high-density in situ station network of daily temperature and precipitation). More than twenty simulations have been performed, all driven by ERA40, with an update of the boundary conditions every 6 hours. In order to avoid spin

  19. SECOND WASTE PACKAGE PROBABILISTIC CRITICALITY ANALYSIS: GENERATION AND EVALUATION OF INTERNAL CRITICIALITY CONFIGURATIONS

    SciTech Connect

    P. Gottlieb, J.R. Massari, J.K. McCoy

    1996-03-27

    This analysis is prepared by the Mined Geologic Disposal System (MGDS) Waste Package Development (WPD) department to provide an evaluation of the criticality potential within a waste package having sonic or all of its contents degraded by corrosion and removal of neutron absorbers. This analysis is also intended to provide an estimate of the consequences of any internal criticality, particularly in terms of any increase in radionuclide inventory. These consequence estimates will be used as part of the WPD input to the Total System Performance Assessment. The ultimate objective of this analysis is to augment the information gained from the Initial Waste Package Probabilistic Criticality Analyses (Ref. 5.8 and 5.9, hereafter referred to as IPA) to a degree which will support preliminary waste package design recommendations intended to reduce the risk of waste package criticality and the risk to total repository system performance posed by the consequences of any criticality. The IPA evaluated the criticality potential under the assumption that the waste package basket retained its structural integrity, so that the assemblies retained their initial separation, even when the neutron absorbers had been leached from the basket. This analysis is based on the more realistic condition that removal of the neutron absorbers is a consequence of the corrosion of the steel in which they are contained, which has the additional consequence of reducing the structural support between assemblies. The result is a set of more reactive configurations having a smaller spacing between assemblies, or no inter-assembly spacing at all. Another difference from the IPA is the minimal attention to probabilistic evaluation given in this study. Although the IPA covered a time horizon to 100,000 years, the lack of consideration of basket degradation modes made it primarily applicable to the first 10,000 years. In contrast, this study, by focusing on the degraded modes of the basket, is primarily

  20. Nonlinear particle dynamics in the magnetotail: A laboratory study 1. The experimental configuration and numerical simulation. Interim report

    SciTech Connect

    Walker, D.; Bowles, J.; Holland, D.; Chen, J.; Siefring, C.

    1995-09-25

    The authors have performed the initial stages of an experiment designed to investigate particle dynamics in the magnetotail. The results of this experiment lend support to the idea that particle scattering from the magnetotail neutral sheet is not random but that there exist resonances in the number and direction of scattered particles as a function of energy. The effort began with construction and testing of the magnetic field configuration necessary to simulate the quitetime magnetotail field: a neutral sheet magnetic field profile B0(z)x with a superimposed normal field B(2)z. Once complete, electrons of variable energy were injected into the field region created and the scattered current collected by back-scattered and forward-scattered collection plates was analyzed as a function of electron energy. The experiment was used to test the hypothesis that single particle scattering from a neutral sheet type profile as described can be coherent and can, at times, demonstrate resonance effects as a function of energy.

  1. Aerodynamic design and analysis of the AST-204, AST-205, and AST-206 blended wing-fuse large supersonic transport configuration concepts

    NASA Technical Reports Server (NTRS)

    Martin, G. L.; Walkley, K. B.

    1980-01-01

    The aerodynamic design and analysis of three blended wing-fuselage supersonic cruise configurations providing four, five, and six abreast seating was conducted using a previously designed supersonic cruise configuration as the baseline. The five abreast configuration was optimized for wave drag at a Mach number of 2.7. The four and six abreast configurations were also optimized at Mach 2.7, but with the added constraint that the majority of their structure be common with the five abreast configuration. Analysis of the three configurations indicated an improvement of 6.0, 7.5, and 7.7 percent in cruise lift-to-drag ratio over the baseline configuration for the four, five, and six abreast configurations, respectively.

  2. Experimental and CFD simulation studies of wall shear stress for different impeller configurations and MBR activated sludge.

    PubMed

    Ratkovich, N; Chan, C C V; Bentzen, T R; Rasmussen, M R

    2012-01-01

    Membrane bioreactors (MBRs) have been used successfully in biological wastewater treatment for effective solids-liquid separation. However, a common problem encountered with MBR systems is fouling of the membrane resulting in frequent membrane cleaning and replacement which makes the system less appealing for full-scale applications. It has been widely demonstrated that the filtration performances in MBRs can be improved by understanding the shear stress over the membrane surface. Modern tools such as computational fluid dynamics (CFD) can be used to diagnose and understand the shear stress in an MBR. Nevertheless, proper experimental validation is required to validate CFD simulation. In this work experimental measurements of shear stress induced by impellers at a membrane surface were made with an electrochemical approach and the results were used to validate CFD simulations. As good results were obtained with the CFD model (<9% error), it was extrapolated to include the non-Newtonian behaviour of activated sludge.

  3. Experimental analysis of computer system dependability

    NASA Technical Reports Server (NTRS)

    Iyer, Ravishankar, K.; Tang, Dong

    1993-01-01

    This paper reviews an area which has evolved over the past 15 years: experimental analysis of computer system dependability. Methodologies and advances are discussed for three basic approaches used in the area: simulated fault injection, physical fault injection, and measurement-based analysis. The three approaches are suited, respectively, to dependability evaluation in the three phases of a system's life: design phase, prototype phase, and operational phase. Before the discussion of these phases, several statistical techniques used in the area are introduced. For each phase, a classification of research methods or study topics is outlined, followed by discussion of these methods or topics as well as representative studies. The statistical techniques introduced include the estimation of parameters and confidence intervals, probability distribution characterization, and several multivariate analysis methods. Importance sampling, a statistical technique used to accelerate Monte Carlo simulation, is also introduced. The discussion of simulated fault injection covers electrical-level, logic-level, and function-level fault injection methods as well as representative simulation environments such as FOCUS and DEPEND. The discussion of physical fault injection covers hardware, software, and radiation fault injection methods as well as several software and hybrid tools including FIAT, FERARI, HYBRID, and FINE. The discussion of measurement-based analysis covers measurement and data processing techniques, basic error characterization, dependency analysis, Markov reward modeling, software-dependability, and fault diagnosis. The discussion involves several important issues studies in the area, including fault models, fast simulation techniques, workload/failure dependency, correlated failures, and software fault tolerance.

  4. Finite element analysis of balloon-expandable coronary stent deployment: influence of angioplasty balloon configuration.

    PubMed

    Martin, David; Boyle, Fergal

    2013-11-01

    Today, the majority of coronary stents are balloon-expandable and are deployed using a balloon-tipped catheter. To improve deliverability, the membrane of the angioplasty balloon is typically folded about the catheter in a pleated configuration. As such, the deployment of the angioplasty balloon is governed by the material properties of the balloon membrane, its folded configuration and its attachment to the catheter. Despite this observation, however, an optimum strategy for modelling the configuration of the angioplasty balloon in finite element studies of coronary stent deployment has not been identified, and idealised models of the angioplasty balloon are commonly employed in the literature. These idealised models often neglect complex geometrical features, such as the folded configuration of the balloon membrane and its attachment to the catheter, which may have a significant influence on the deployment of a stent. In this study, three increasingly sophisticated models of a typical semi-compliant angioplasty balloon were employed to determine the influence of angioplasty balloon configuration on the deployment of a stent. The results of this study indicate that angioplasty balloon configuration has a significant influence on both the transient behaviour of the stent and its impact on the mechanical environment of the coronary artery.

  5. Configuration and validation of an analytical model predicting secondary neutron radiation in proton therapy using Monte Carlo simulations and experimental measurements.

    PubMed

    Farah, J; Bonfrate, A; De Marzi, L; De Oliveira, A; Delacroix, S; Martinetti, F; Trompier, F; Clairand, I

    2015-05-01

    This study focuses on the configuration and validation of an analytical model predicting leakage neutron doses in proton therapy. Using Monte Carlo (MC) calculations, a facility-specific analytical model was built to reproduce out-of-field neutron doses while separately accounting for the contribution of intra-nuclear cascade, evaporation, epithermal and thermal neutrons. This model was first trained to reproduce in-water neutron absorbed doses and in-air neutron ambient dose equivalents, H*(10), calculated using MCNPX. Its capacity in predicting out-of-field doses at any position not involved in the training phase was also checked. The model was next expanded to enable a full 3D mapping of H*(10) inside the treatment room, tested in a clinically relevant configuration and finally consolidated with experimental measurements. Following the literature approach, the work first proved that it is possible to build a facility-specific analytical model that efficiently reproduces in-water neutron doses and in-air H*(10) values with a maximum difference less than 25%. In addition, the analytical model succeeded in predicting out-of-field neutron doses in the lateral and vertical direction. Testing the analytical model in clinical configurations proved the need to separate the contribution of internal and external neutrons. The impact of modulation width on stray neutrons was found to be easily adjustable while beam collimation remains a challenging issue. Finally, the model performance agreed with experimental measurements with satisfactory results considering measurement and simulation uncertainties. Analytical models represent a promising solution that substitutes for time-consuming MC calculations when assessing doses to healthy organs. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  6. Constructing Flexible, Configurable, ETL Pipelines for the Analysis of "Big Data" with Apache OODT

    NASA Astrophysics Data System (ADS)

    Hart, A. F.; Mattmann, C. A.; Ramirez, P.; Verma, R.; Zimdars, P. A.; Park, S.; Estrada, A.; Sumarlidason, A.; Gil, Y.; Ratnakar, V.; Krum, D.; Phan, T.; Meena, A.

    2013-12-01

    A plethora of open source technologies for manipulating, transforming, querying, and visualizing 'big data' have blossomed and matured in the last few years, driven in large part by recognition of the tremendous value that can be derived by leveraging data mining and visualization techniques on large data sets. One facet of many of these tools is that input data must often be prepared into a particular format (e.g.: JSON, CSV), or loaded into a particular storage technology (e.g.: HDFS) before analysis can take place. This process, commonly known as Extract-Transform-Load, or ETL, often involves multiple well-defined steps that must be executed in a particular order, and the approach taken for a particular data set is generally sensitive to the quantity and quality of the input data, as well as the structure and complexity of the desired output. When working with very large, heterogeneous, unstructured or semi-structured data sets, automating the ETL process and monitoring its progress becomes increasingly important. Apache Object Oriented Data Technology (OODT) provides a suite of complementary data management components called the Process Control System (PCS) that can be connected together to form flexible ETL pipelines as well as browser-based user interfaces for monitoring and control of ongoing operations. The lightweight, metadata driven middleware layer can be wrapped around custom ETL workflow steps, which themselves can be implemented in any language. Once configured, it facilitates communication between workflow steps and supports execution of ETL pipelines across a distributed cluster of compute resources. As participants in a DARPA-funded effort to develop open source tools for large-scale data analysis, we utilized Apache OODT to rapidly construct custom ETL pipelines for a variety of very large data sets to prepare them for analysis and visualization applications. We feel that OODT, which is free and open source software available through the Apache

  7. Experimental signal analysis in ion mobility spectrometry

    NASA Astrophysics Data System (ADS)

    Goubran, R. A.; Lawrence, A. H.

    1991-03-01

    The mathematical differentiation of experimental signals is often used as a resolution enhancement technique, to facilitate the detection and location of partially overlapped gaussian peaks in a multi-component signal. In this paper the analysis of the peak shapes of real ion mobility spectrometry (IMS) signals indicated that a gaussian approximation leads to less than 0.035% of mean square error (using a window of ± 3[sigma] around the peak) while the analysis of the noise signal (performed both in the time and frequency domains) showed that it could be modelled as filtered white gaussian noise. The experimental signal data were provided through the IMS sampling of the chemicals diazepam, lorazepam and bromazepan. Given these findings, a model capable of simulating IMS peaks with any desired time separation, relative amplitude, or additive noise level was developed. It then became possible to quantitatively evaluate the performance and limitations of the second derivative peak detection algorithm. Peak resolution down to 0.27 ms and signal-to-noise ratios down to 18 d[circle dot operator]B were achieved. Some preliminary results obtained with higher order derivative algorithms are also presented.

  8. An Experimental Test of How Different Community Configurations and Environmental Pressures Influence the Susceptibility of Ponds to a Critical Transition

    NASA Astrophysics Data System (ADS)

    Gregory-Eaves, I.; Iacarella, J.; Giani, A.; Beisner, B. E.

    2015-12-01

    Over the past two centuries, humans have been modifying the planet at an accelerating rate and, in some cases, ecosystems have been observed to experience critical transitions. For example, shallow lakes and ponds may change abruptly from a clear-water, macrophyte-dominated state to a turbid state when exposed to minor increases in stress (e.g., nutrient loading). Yet, abrupt changes in shallow lakes and ponds are not consistently observed and considerable uncertainty remains regarding the ecological and environmental conditions that render these systems susceptible to sudden changes. To address this knowledge gap, we are conducting a mesocosm experiment to quantify how different community configurations and environmental pressures influence the susceptibility of ponds to critical transitions. This research tests the hypothesis that macrophyte density and the rate of external nutrient loading alter the trajectory of phytoplankton dynamics, thus influencing the transition to a turbid state. We supplied 18 mesocosms with field-collected sediment, phytoplankton, zooplankton and fish, and exposed them to three levels of macrophyte densities and two external nutrient loading regimes. Based on daily measurements of phytoplankton biomass (measured as chlorophyll a), we will apply early warning metrics for identifying critical transitions (e.g., http://www.early-warning-signals.org). Our preliminary results indicate that ponds with no macrophytes and the faster nutrient loading rate yield the greatest rate of increase in chlorophyll a. Key goals of this experiment are to enhance the mechanistic understanding of shallow lake and pond dynamics, and aid in the interpretation of lake sediment records as archives of historical critical transitions.

  9. Preventing Instrumentation Failure in Three-Column Spinal Osteotomy: Biomechanical Analysis of Rod Configuration.

    PubMed

    Jager, Zachary S; İnceoğlu, Serkan; Palmer, Daniel; Akpolat, Yusuf T; Cheng, Wayne K

    2016-01-01

    Biomechanical analysis. To show the role of additional rods and long-term fatigue strength to prevent the instrumentation failure on three-column osteotomies. Three-column osteotomy such as pedicle subtraction osteotomy (PSO) and vertebral column resections are surgical correction options for fixed spinal deformity. Posterior fixation for the PSO involves pedicle screw-and rod-based instrumentation, with the rods being contoured to accommodate the accentuated lordosis. Pseudarthrosis and instrumentation failure are known complications of PSO. Unilateral pedicle screw and rod constructs were mounted in ultra-high-molecular-weight polyethylene blocks using a vertebrectomy model with the rods contoured to simulate posterior fixation of a PSO. Each construct was cycled under a 200 N load at 5 Hz in simulated flexion and extension to rod failure. Three configurations (n = 5) of titanium alloy rods were tested: single rod (control), double rod, and bridging rod. Outcomes were total cycles to failure and location of rod failure. Double-rod and bridging-rod constructs had a significantly higher number of cycles to failure compared with the single-rod construct (p < .05). Single-rod constructs failed at or near the rod bend apex, whereas the majority of double-rod and bridging-rod constructs failed at the screw-rod or rod-connector junction. Double-rod and bridging-rod constructs are more resistant to fatigue failure compared with single-rod constructs in PSO instrumentation and could be considered to mitigate the risk of instrumentation failure. Copyright © 2016 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.

  10. Experimental study on the effects of blast-cap configurations and charge patterns on coke descending in CDQ cooling shaft

    SciTech Connect

    Y.H. Feng; X.X. Zhang; M.L. Wu

    2008-08-15

    The coke descending behavior in a CDQ cooling shaft is studied experimentally by means of a tracing method with a digital camera. For three different blast-caps, the law of coke flow is studied under five conditions of coke charge. The experimental results show that, for the sake of the uniformity of the coke burden descending, a blast-cap with elliptical cross-section is a better choice than that with circular cross-section regardless of high or low placement. A coke charge pattern with a flat top burden surface is preferable to that with peak-valley surface, a double-peak superior to a one-peak. Trajectory and average velocity distribution of coke behavior depend weakly on whether the coke is continuously fed or not as the discharging began. The blast-caps have local effects on the descending coke and hardly affect whether the cokes flow smoothly or not in the case of coke burden with enough depth.

  11. Intelligent self-configuring client-server analysis software for high-resolution X and gamma-ray spectrometry

    SciTech Connect

    Buckley, W.M.; Carlson, J.

    1995-07-01

    The Safeguards Technology Program at the Lawrence Livermore National Laboratory is developing isotopic analysis software that is constructed to be adaptable to a wide variety of applications and requirements. The MGA++ project will develop an analysis capability based on an architecture consisting of a set of tools that can be configured by an executive to perform a specific task. The software will check the results or progress of an analysis and change assumptions and methodology as required to arrive at an optimum analysis. The software is intended to address analysis needs that arise from material control and accountability, treaty verification, complex reconfiguration and environmental clean-up applications.

  12. Configurational Analysis of Tetracyclic Dimeric Pyrrole-Imidazole Alkaloids using a Floating Chirality Approach

    PubMed Central

    Köck, Matthias; Schmidt, Gesine; Seiple, Ian B.; Baran, Phil S.

    2012-01-01

    The structure elucidation of the palau'amine congener tetrabromostyloguanidine (1), which used interproton distances from ROESY spectra as restraints in a computational approach, the so-called fc-rDG/DDD method, led to a revision of the relative configuration of palau'amine (2) and its congeners in 2007. The recent total synthesis of (±)-palau'amine (2) subsequently confirmed the computed structural revision of the relative configuration. In order to test a broader application range of the fc-rDG/DDD method, the present study investigated two additional dimeric pyrrole-imidazole alkaloids, axinellamine A (3) and 3,7-epi-massadine chloride (4). These calculations allowed the simultaneous assignment of the relative configuration for all eight stereogenic centers of compounds 3 and 4 without using any information from the reported configurations. In contrast to the palau'amine congeners, the fc-rDG/DDD method confirmed the relative configuration originally described for axinellamine A (3) and 3,7-epi-massadine chloride (4). PMID:22332969

  13. Configurational analysis of tetracyclic dimeric pyrrole-imidazole alkaloids using a floating chirality approach.

    PubMed

    Köck, Matthias; Schmidt, Gesine; Seiple, Ian B; Baran, Phil S

    2012-02-24

    The structure elucidation of the palau'amine congener tetrabromostyloguanidine (1), which used interproton distances from ROESY spectra as restraints in a computational approach, the so-called fc-rDG/DDD method, led to a revision of the relative configuration of palau'amine (2) and its congeners in 2007. The recent total synthesis of (±)-palau'amine (2) subsequently confirmed the computed structural revision of the relative configuration. In order to test a broader application range of the fc-rDG/DDD method, the present study investigated two additional dimeric pyrrole-imidazole alkaloids, axinellamine A (3) and 3,7-epi-massadine chloride (4). These calculations allowed the simultaneous assignment of the relative configuration for all eight stereogenic centers of compounds 3 and 4 without using any information from the reported configurations. In contrast to the palau'amine congeners, the fc-rDG/DDD method confirmed the relative configuration originally described for axinellamine A (3) and 3,7-epi-massadine chloride (4).

  14. Euler/Navier-Stokes flow computations on flexible configurations for stability analysis

    NASA Technical Reports Server (NTRS)

    Guruswamy, G.; Tu, E.

    1995-01-01

    Longitudinal dynamic stability derivatives required for design of aircraft are computed by using the state-of-the-art numerical methods for wing-body configurations. The flow is modeled using the Euler/Navier-Stokes equations with turbulence models and solved using an efficient finite-difference scheme suitable for patched structured grids. Computations are made at a flow regime that is beyond the limits of the current linear methods mostly used for computing stability derivatives. Flow conditions include shockwaves and viscous dominated vortical flows. Effect of Mach number and angle-of-attack on stability derivatives are demonstrated for a typical wing-body configuration. For the same configuration the effects of wing flexibility on the magnitude and phase angles of stability derivatives are also demonstrated.

  15. Analysis and in-simulator evaluation of display and control concepts for a terminal configured vehicle in final approach in a windshear environment

    NASA Technical Reports Server (NTRS)

    Levison, W. H.

    1978-01-01

    Display Control configurations for the Terminal configured Vehicle in approach to landing situations were analyzed. A pilot/vehicle model was used to compare with a real time simulation study. Model results are presented and extended for the approach task during wind shear and random turbulence environments. In general, model results of performance trends matched those obtained experimentally.

  16. Determination and analysis of an analytical potential for ions in excited configurations in plasmas

    NASA Astrophysics Data System (ADS)

    Rodriguez Perez, Rafael

    The main objective in this Thesis is to propose an analytical expression, within the context of the Independent Particle Model in a central field, for the effective potential that a bound electron feels when it belongs to an ion which is in an excited configuration. It is also an objective that this potential will be obtained as a correction to the effective potential corresponding to the ion in ground state. The potential proposed not only allows to include the effects that the excited configurations introduce on atomic magnitudes but also allows to broach, in a simple and fast way, how to determine the ionic populations and the optical properties of plasmas. The great advantage of the analytical potentials is that they avoid the iterative procedures, which are characteristic in the self-consistent methods, in the calculations of atomic magnitudes and plasma properties. This fact allow a considerable diminution in calculation time. Moreover, the analytical potential proposed in this Thesis has the advantage with respect other analytical potentials that it does not need to fit its parameters when we consider different excited configurations. This fact implies a considerable diminution in the complexity of the problem and in the calculation time and allows to include more excited configurations to model the ions present in the plasma, which improves the results. With the potential proposed in this Thesis we have studied the influence of the excited configurations on atomic magnitudes. Those results have been checked satisfactorily with others obtained by self-consistent methods and by using analytical potentials. We have also used the potential proposed to determine which excited configurations have more probability of presence in a plasma in Local Thermodynamic Equilibrium.

  17. On the scaling analysis of the solute boundary layer in idealized growth configurations

    NASA Astrophysics Data System (ADS)

    Garandet, J. P.; Duffar, T.; Favier, J. J.

    1990-11-01

    A scaling procedure is applied to the equation governing chemical transport in idealized Czochralski and horizontal Bridgman growth experiments. Our purpose is to get a fair estimate of the solute boundary layer in front of the solidification interface. The results are very good in the Czochralski type configuration, the maximum error with respect to the semi-analytical solution of Burton, Prim and Schlichter being of the order of 20%. In the Bridgman type configuration, our predictions compare well with the values of the numerical simulations; however, more data would be needed for a definite conclusion to be drawn.

  18. Experimental analysis of direct current corona discharge

    NASA Astrophysics Data System (ADS)

    lagăr, A.; Diniş, C. M.; Popa, G. N.

    2017-01-01

    This paper presents the experimental analysis of current-voltage characteristic of DC corona discharge. In experiments were used an electrostatic discharge system, consists of an active brass electrode, and a passive copper electrode (plane). A high-voltage source has been used to produce the positive or negative DC discharge. To analyse the influence of active electrode surface were used a conical and a spherical electrode, with small radius of curvature. The gap between the electrodes was varied by moving the passive electrode. Current-voltage characteristics of DC corona discharge were obtained at a constant distance between the discharge electrodes, by changing the amplitude of supply voltage. Corona current and voltage were acquired using a digital oscilloscope. Experiments allowed the study of the effects due to the active electrode and the air gap between the electrodes, on the onset voltage and the current of corona discharge.

  19. Experimental and analysis methods in radiochemical experiments

    NASA Astrophysics Data System (ADS)

    Cattadori, C. M.; Pandola, L.

    2016-04-01

    Radiochemical experiments made the history of neutrino physics by achieving the first observation of solar neutrinos (Cl experiment) and the first detection of the fundamental pp solar neutrinos component (Ga experiments). They measured along decades the integral νe charged current interaction rate in the exposed target. The basic operation principle is the chemical separation of the few atoms of the new chemical species produced by the neutrino interactions from the rest of the target, and their individual counting in a low-background counter. The smallness of the expected interaction rate (1 event per day in a ˜ 100 ton target) poses severe experimental challenges on the chemical and on the counting procedures. The main aspects related to the analysis techniques employed in solar neutrino experiments are reviewed and described, with a special focus given to the event selection and the statistical data treatment.

  20. Unsteady aerodynamic flow field analysis of the space shuttle configuration. Part 1: Orbiter aerodynamics

    NASA Technical Reports Server (NTRS)

    Ericsson, L. E.; Reding, J. P.

    1976-01-01

    An analysis of the steady and unsteady aerodynamics of the space shuttle orbiter has been performed. It is shown that slender wing theory can be modified to account for the effect of Mach number and leading edge roundness on both attached and separated flow loads. The orbiter unsteady aerodynamics can be computed by defining two equivalent slender wings, one for attached flow loads and another for the vortex-induced loads. It is found that the orbiter is in the transonic speed region subject to vortex-shock-boundary layer interactions that cause highly nonlinear or discontinuous load changes which can endanger the structural integrity of the orbiter wing and possibly cause snap roll problems. It is presently impossible to simulate these interactions in a wind tunnel test even in the static case. Thus, a well planned combined analytic and experimental approach is needed to solve the problem.

  1. Analysis of Post-Support and Wind-Tunnel Wall Interference on Flow Field About Subsonic High-Lift High-Speed Research Configuration

    NASA Technical Reports Server (NTRS)

    Lessard, Wendy B.

    2000-01-01

    The present study was performed to determine how significant the interference effects of the wind-tunnel model support system and tunnel walls can be for a high-speed configuration during takeoff and landing conditions. A 5-percent scale model of the Technology Concept Airplane was recently tested in the Langley 14- by 22-Foot Sub-sonic Tunnel. The model was numerically modeled with and without the support and tunnel walls and compared with experimental data. Detailed analysis of the flow provided additional insight concerning what effects the post support and tunnel walls had on the flow field. This study revealed that although the overall forces and moments could be experimentally accounted for, the detailed flow features, such as the surface pressure distributions, could not be accurately simulated without including the post support in the computations.

  2. Optimization of Simplex Atomizer Inlet Port Configuration through Computational Fluid Dynamics and Experimental Study for Aero-Gas Turbine Applications

    NASA Astrophysics Data System (ADS)

    Marudhappan, Raja; Chandrasekhar, Udayagiri; Hemachandra Reddy, Koni

    2017-10-01

    The design of plain orifice simplex atomizer for use in the annular combustion system of 1100 kW turbo shaft engine is optimized. The discrete flow field of jet fuel inside the swirl chamber of the atomizer and up to 1.0 mm downstream of the atomizer exit are simulated using commercial Computational Fluid Dynamics (CFD) software. The Euler-Euler multiphase model is used to solve two sets of momentum equations for liquid and gaseous phases and the volume fraction of each phase is tracked throughout the computational domain. The atomizer design is optimized after performing several 2D axis symmetric analyses with swirl and the optimized inlet port design parameters are used for 3D simulation. The Volume Of Fluid (VOF) multiphase model is used in the simulation. The orifice exit diameter is 0.6 mm. The atomizer is fabricated with the optimized geometric parameters. The performance of the atomizer is tested in the laboratory. The experimental observations are compared with the results obtained from 2D and 3D CFD simulations. The simulated velocity components, pressure field, streamlines and air core dynamics along the atomizer axis are compared to previous research works and found satisfactory. The work has led to a novel approach in the design of pressure swirl atomizer.

  3. Optimization of Simplex Atomizer Inlet Port Configuration through Computational Fluid Dynamics and Experimental Study for Aero-Gas Turbine Applications

    NASA Astrophysics Data System (ADS)

    Marudhappan, Raja; Chandrasekhar, Udayagiri; Hemachandra Reddy, Koni

    2016-06-01

    The design of plain orifice simplex atomizer for use in the annular combustion system of 1100 kW turbo shaft engine is optimized. The discrete flow field of jet fuel inside the swirl chamber of the atomizer and up to 1.0 mm downstream of the atomizer exit are simulated using commercial Computational Fluid Dynamics (CFD) software. The Euler-Euler multiphase model is used to solve two sets of momentum equations for liquid and gaseous phases and the volume fraction of each phase is tracked throughout the computational domain. The atomizer design is optimized after performing several 2D axis symmetric analyses with swirl and the optimized inlet port design parameters are used for 3D simulation. The Volume Of Fluid (VOF) multiphase model is used in the simulation. The orifice exit diameter is 0.6 mm. The atomizer is fabricated with the optimized geometric parameters. The performance of the atomizer is tested in the laboratory. The experimental observations are compared with the results obtained from 2D and 3D CFD simulations. The simulated velocity components, pressure field, streamlines and air core dynamics along the atomizer axis are compared to previous research works and found satisfactory. The work has led to a novel approach in the design of pressure swirl atomizer.

  4. Multi-Scale Creep Analysis of Plain-Woven Laminates Using Time-Dependent Homogenization Theory:. Effects of Laminate Configuration

    NASA Astrophysics Data System (ADS)

    Nakata, K.; Matsuda, T.; Kawai, M.

    In this study, multi-scale creep analysis of plain-woven GFRP laminates is performed using the time-dependent homogenization theory developed by the present authors. First, point-symmetry of internal structures of plain-woven laminates is utilized for a boundary condition of unit cell problems, reducing the domain of analysis to 1/4 and 1/8 for in-phase and out-of-phase laminate configurations, respectively. The time-dependent homogenization theory is then reconstructed for these domains of analysis. Using the present method, in-plane creep behavior of plain-woven glass fiber/epoxy laminates subjected to a constant stress is analyzed. The results are summarized as follows: (1) The in-plane creep behavior of the plain-woven GFRP laminates exhibits marked anisotropy. (2) The laminate configurations considerably affect the creep behavior of the laminates.

  5. Analysis of high-speed growth of silicon sheet in inclined-meniscus configuration

    NASA Technical Reports Server (NTRS)

    Thomas, P. D.; Brown, R. A.

    1985-01-01

    The study of high speed growth of silicon sheet in inclined-meniscus configurations is discussed. It was concluded that the maximum growth rates in vertical and inclined growth are set by thermal-capillary limits. Also, the melt/crystal interface was determined to be flat. And, vertical growth is qualitatively modelled by one dimensional heat transfer.

  6. An Empirical Analysis of an Alternative Configuration of the Academic Motivation Scale

    ERIC Educational Resources Information Center

    Smith, Kenneth J.; Davy, Jeanette A.; Rosenberg, Donald L.

    2012-01-01

    The purpose of this study was to examine an alternative configuration of the Academic Motivation Scale (AMS), a psychometric instrument used as a measure of academic motivation in various academic environments. The analyses utilised data from a convenience sample of 2354 business students, broken into two random subsamples of 1177 cases.…

  7. An Empirical Analysis of an Alternative Configuration of the Academic Motivation Scale

    ERIC Educational Resources Information Center

    Smith, Kenneth J.; Davy, Jeanette A.; Rosenberg, Donald L.

    2012-01-01

    The purpose of this study was to examine an alternative configuration of the Academic Motivation Scale (AMS), a psychometric instrument used as a measure of academic motivation in various academic environments. The analyses utilised data from a convenience sample of 2354 business students, broken into two random subsamples of 1177 cases.…

  8. Analysis of pronuclear zygote configurations in 459 clinical pregnancies obtained with assisted reproductive technique procedures.

    PubMed

    Nicoli, Alessia; Capodanno, Francesco; Moscato, Lucia; Rondini, Ilaria; Villani, Maria T; Tuzio, Antonella; La Sala, Giovanni B

    2010-06-25

    Embryos selection is crucial to maintain high performance in terms of pregnancy rate, reducing the risk of multiple pregnancy during IVF. Pronuclear and nucleolar characteristics have been proposed as an indicator of embryo development and chromosomal complement in humans, providing information about embryo viability. To correlate the zygote-score with the maternal age and the outcome of pregnancy, we analyzed the pronuclear and nucleolar morphology, the polar body alignment and the zygote configuration in 459 clinical pregnancies obtained by IVF and ICSI in our public clinic in Reggio Emilia, Italy. We derived odds ratios (OR) and Corenfield's 95% confidence intervals (CI). Continuous variables were compared with Student's t-test; P lower than .05 was considered statistically significant. We observed a significant increase of "A" pronuclear morphology configuration in 38-41 years old patients in comparison to that lower than or equal to 32 years old and a significant decrease of "B" configuration in 38-41 years old patients in comparison to that lower than or equal to 32 and in comparison to that of 33-37 years old. Related to maternal age we found no significant differences in P1 and in P2 configuration. We found no correlation between zygote-score, embryo cleavage and embryo quality. Our results confirm the limited clinical significance of zygote-score suggesting that it can not be associated with maternal age, embryo cleavage and embryo quality. The evaluation of embryo quality based on morphological parameters is probably more predictive than zygote-score.

  9. Heat Transfer Retardation at Elevated Temperatures. Phase I. Analysis of Heat Transfer Retardation Configurations and Materials.

    DTIC Science & Technology

    1983-09-01

    aluminum foil (0.002 in. thick). The other configuration tested was formed with alternate layers of an insulating paper (" Fiberfrax " paper, which has...because " Fiberfrax " has a density of about 15 Ibm/ft3 , as compared to the Dynaquartz density of 4 to 7 lbm/ft 3 depending on the compaction. Thus the

  10. Aerodynamic analysis of three advanced configurations using the TranAir full-potential code

    NASA Technical Reports Server (NTRS)

    Madson, M. D.; Carmichael, R. L.; Mendoza, J. P.

    1989-01-01

    Computational results are presented for three advanced configurations: the F-16A with wing tip missiles and under wing fuel tanks, the Oblique Wing Research Aircraft, and an Advanced Turboprop research model. These results were generated by the latest version of the TranAir full potential code, which solves for transonic flow over complex configurations. TranAir embeds a surface paneled geometry definition in a uniform rectangular flow field grid, thus avoiding the use of surface conforming grids, and decoupling the grid generation process from the definition of the configuration. The new version of the code locally refines the uniform grid near the surface of the geometry, based on local panel size and/or user input. This method distributes the flow field grid points much more efficiently than the previous version of the code, which solved for a grid that was uniform everywhere in the flow field. TranAir results are presented for the three configurations and are compared with wind tunnel data.

  11. Analysis of HIF-1 inhibition by manassantin A and analogues with modified tetrahydrofuran configurations

    PubMed Central

    Kasper, Amanda C.; Moon, Eui Jung; Hu, Xiangqian; Park, Yongho; Wooten, Ceshea M.; Kim, Hyoungsu; Yang, Weitao; Dewhirst, Mark W.; Hong, Jiyong

    2009-01-01

    We have shown that manassantin A downregulated the HIF-1α expression and inhibited the secretion of VEGF. We have also demonstrated that the 2,3-cis-3,4-trans-4,5-cis-configuration of the tetrahydrofuran is critical to the HIF-1 inhibition of manassantin A. PMID:19423348

  12. Analysis of HIF-1 inhibition by manassantin A and analogues with modified tetrahydrofuran configurations.

    PubMed

    Kasper, Amanda C; Moon, Eui Jung; Hu, Xiangqian; Park, Yongho; Wooten, Ceshea M; Kim, Hyoungsu; Yang, Weitao; Dewhirst, Mark W; Hong, Jiyong

    2009-07-15

    We have shown that manassantin A downregulated the HIF-1alpha expression and inhibited the secretion of VEGF. We have also demonstrated that the 2,3-cis-3,4-trans-4,5-cis-configuration of the tetrahydrofuran is critical to the HIF-1 inhibition of manassantin A.

  13. Transonic perturbation analysis of wing-fuselage-nacelle-pylon configurations with powered jet exhausts

    NASA Technical Reports Server (NTRS)

    Wai, J. C.; Sun, C. C.; Yoshihara, H.

    1982-01-01

    A method using a transonic small disturbance code with successive line over-relaxation is described for treating wing/fuselage configurations with a nacelle/pylon/powered jet. Examples illustrating its use for the NASA transport research model are given. Reasonable test/theory comparisons were obtained.

  14. Experimental study of the lift and drag characteristics of a cascade of flat plates in a configuration of interest for tidal energy converters

    NASA Astrophysics Data System (ADS)

    Fedoul, Faical; Parras, Luis; Del Pino, Carlos; Fernandez-Feria, Ramon

    2012-11-01

    Wind tunnel experiments are conducted for the flow around both a single flat plate and a cascade of three parallel flat plates at different angles of incidence to compare their lift and drag coefficients in a range of Reynolds number about 105, and for two values of the aspect ratio of the flat plates. The selected cascade configuration is of interest for a particular type of tidal energy converter. The lift and drag characteristics of the central plate in the cascade are compared to those of the isolated plate, finding that there exist an angle of incidence, which depends on the Reynolds number and the aspect ratio, above which the effective lift of the plate in the cascade becomes larger than that of an isolated plate. These experimental results, which are also analyzed in the light of theoretical predictions, are used as a guide for the design of the optimum configuration of the cascade which extracts the maximum power from a tidal current for a given value of the Reynolds number. Supported by the Ministerio de Ciencia e Innovacion (Spain) Grant no. ENE2010-16851.

  15. Critical assessment of precracked specimen configuration and experimental test variables for stress corrosion testing of 7075-T6 aluminum alloy plate

    NASA Technical Reports Server (NTRS)

    Domack, M. S.

    1985-01-01

    A research program was conducted to critically assess the effects of precracked specimen configuration, stress intensity solutions, compliance relationships and other experimental test variables for stress corrosion testing of 7075-T6 aluminum alloy plate. Modified compact and double beam wedge-loaded specimens were tested and analyzed to determine the threshold stress intensity factor and stress corrosion crack growth rate. Stress intensity solutions and experimentally determined compliance relationships were developed and compared with other solutions available in the literature. Crack growth data suggests that more effective crack length measurement techniques are necessary to better characterize stress corrosion crack growth. Final load determined by specimen reloading and by compliance did not correlate well, and was considered a major source of interlaboratory variability. Test duration must be determined systematically, accounting for crack length measurement resolution, time for crack arrest, and experimental interferences. This work was conducted as part of a round robin program sponsored by ASTM committees G1.06 and E24.04 to develop a standard test method for stress corrosion testing using precracked specimens.

  16. Critical assessment of precracked specimen configuration and experimental test variables for stress corrosion testing of 7075-T6 aluminum alloy plate

    NASA Technical Reports Server (NTRS)

    Domack, M. S.

    1985-01-01

    A research program was conducted to critically assess the effects of precracked specimen configuration, stress intensity solutions, compliance relationships and other experimental test variables for stress corrosion testing of 7075-T6 aluminum alloy plate. Modified compact and double beam wedge-loaded specimens were tested and analyzed to determine the threshold stress intensity factor and stress corrosion crack growth rate. Stress intensity solutions and experimentally determined compliance relationships were developed and compared with other solutions available in the literature. Crack growth data suggests that more effective crack length measurement techniques are necessary to better characterize stress corrosion crack growth. Final load determined by specimen reloading and by compliance did not correlate well, and was considered a major source of interlaboratory variability. Test duration must be determined systematically, accounting for crack length measurement resolution, time for crack arrest, and experimental interferences. This work was conducted as part of a round robin program sponsored by ASTM committees G1.06 and E24.04 to develop a standard test method for stress corrosion testing using precracked specimens.

  17. Analysis of the interaction between experimental and applied behavior analysis.

    PubMed

    Virues-Ortega, Javier; Hurtado-Parrado, Camilo; Cox, Alison D; Pear, Joseph J

    2014-01-01

    To study the influences between basic and applied research in behavior analysis, we analyzed the coauthorship interactions of authors who published in JABA and JEAB from 1980 to 2010. We paid particular attention to authors who published in both JABA and JEAB (dual authors) as potential agents of cross-field interactions. We present a comprehensive analysis of dual authors' coauthorship interactions using social networks methodology and key word analysis. The number of dual authors more than doubled (26 to 67) and their productivity tripled (7% to 26% of JABA and JEAB articles) between 1980 and 2010. Dual authors stood out in terms of number of collaborators, number of publications, and ability to interact with multiple groups within the field. The steady increase in JEAB and JABA interactions through coauthors and the increasing range of topics covered by dual authors provide a basis for optimism regarding the progressive integration of basic and applied behavior analysis. © Society for the Experimental Analysis of Behavior.

  18. Theoretical and experimental pressure distributions for a 71.2 degree swept arrow-wing configuration at subsonic, transonic, and supersonic speeds

    NASA Technical Reports Server (NTRS)

    Bobbitt, P. J.; Manro, M. E.

    1976-01-01

    A wind-tunnel test of an arrow-wing body configuration consisting of flat and twisted wings, as well as a variety of leading- and trailing-edge control-surface deflections, was conducted at Mach numbers from 0.40 to 2.50 to provide an experimental data base for comparison with theoretical methods. Theory-to-experiment comparisons of detailed pressure distributions were made using current state-of-the-art and newly developed attached- and separated-flow methods. Conditions were delineated under which these theories provide accurate basic and incremental aeroelastic loads predictions. Current state-of-the-art linear and nonlinear attached-flow methods were adequate only at small-angle-of-attack cruise conditions. Of the several separated-vortex methods evaluated, only the one utilizing a combination of linear source and quadratically varying doublet panels showed promise of yielding accurate loads distributions at moderate to large angles of attack.

  19. Computational analysis of experimental results on spatial distributions of fission reaction rates in the annular core of a modular HTGR, obtained at the ASTRA critical facility

    SciTech Connect

    Boyarinov, V. F.; Glushkov, E. S.; Fomichenko, P. A.; Kompaniets, G. V.; Krutov, A. M.; Marova, E. V.; Nevinitsa, V. A.; Polyakov, D. N.; Smirnov, O. N.; Sukharev, Y. P.; Zimin, A. A.

    2006-07-01

    The paper presents computational analysis of some experimental results on spatial distribution of {sup 235}U fission reaction rates in a critical assembly with the annular core and different configurations of safety rods, placed into the inner reflector, made of graphite. Presented computational analysis of experimental data was performed with the set of codes used in HTGR design calculations. (authors)

  20. Optimal double screw configuration for subtalar arthrodesis: a finite element analysis.

    PubMed

    Lee, Jun Young; Lee, Yeon Soo

    2011-05-01

    The subtalar arthrodesis using screws has been performed to manage traumatic subtalar arthritis. Even though clinically there might not have been big difference between using single screw or double screws for subtalar arthrodesis, a double screw fixation is expected to bring a better initial stability in a mechanical view. This study aimed to assess the optimal configuration of double screw fixation for subtalar arthrodesis. From the CT-scanned images of an ankle of a Korean male (21 year old), polygon models of the talus and calcaneus were reconstructed. The polygon models were converted to tetrahedron finite elements. Young's modulus was assigned locally to each element based on the Hounsfield unit, and a Poisson's ratio of 0.4 was commonly. Four fixation configurations of double screw subtalar arthrodesis were modeled by combination of a same placement of a neck screw and one of four different placements of a dome screw, i.e., anterolateral (AL), anteromedial (AM), posterolateral (PL), and posteromedial (PM) placements. External and internal rotation torques of 4 N-m were applied when evaluating the stability of each fixation configuration. Among the four fixation configurations, the fixation configuration of a neck screw plus a PM dome screw had the least translation of 0.9 and 0.8 mm for external and internal rotational torques of 4 N-m, respectively. The fixation configuration of a neck screw plus a PM dome screw showed the least rotation of 5.0° and 4.8° for external and internal rotational torques of 4 N-m, respectively. The divergence angle or the contact length did not solely match well to the better stability. However, the integration of both the divergence angle of 2 screws and the contact length between screw and bones were proportionally related to the better rotational stability. A posteromedial dome screw combined with a neck screw can be the best surgical choice, which will bring out excellent union rate of the subtalar arthrodesis as well

  1. Module Configuration

    DOEpatents

    Oweis, Salah; D'Ussel, Louis; Chagnon, Guy; Zuhowski, Michael; Sack, Tim; Laucournet, Gaullume; Jackson, Edward J.

    2002-06-04

    A stand alone battery module including: (a) a mechanical configuration; (b) a thermal management configuration; (c) an electrical connection configuration; and (d) an electronics configuration. Such a module is fully interchangeable in a battery pack assembly, mechanically, from the thermal management point of view, and electrically. With the same hardware, the module can accommodate different cell sizes and, therefore, can easily have different capacities. The module structure is designed to accommodate the electronics monitoring, protection, and printed wiring assembly boards (PWAs), as well as to allow airflow through the module. A plurality of modules may easily be connected together to form a battery pack. The parts of the module are designed to facilitate their manufacture and assembly.

  2. Role of mechanical forces in hand nail configuration asymmetry in hemiplegia: an analysis of four hundred thumb nails.

    PubMed

    Sano, H; Ogawa, R

    2013-01-01

    To assess the relationship between nail configuration and mechanical force, the nail morphology and pinch strengths of the paralyzed and non-paralyzed sides of patients with hemiplegia were measured. Study 1: Analysis of nail configuration. Both thumb nails of 100 subjects with hemiplegia and 100 healthy volunteers (400 thumb nails) were enrolled. The left and right thumb nails were compared in terms of configuration, namely the curve index (defined as nail height/width). Study 2: Measurement of pinch strength. In 10 subjects with hemiplegia and 10 healthy volunteers, the pinch strengths of both sides were compared. Study 1: In the subjects with hemiplegia, the palsy side had a significantly higher curve index than the non-palsy side (32.7 ± 8.3 vs. 24.4 ± 6.5%). The two sides of the healthy volunteers did not differ significantly in terms of the curve index. Study 2: In all hemiplegia cases, the non-palsy side had a higher pinch strength. The differences were statistically significant (4.40 ± 1.90 vs. 0.05 ± 0.16 kg). In the healthy volunteers, the dominant and non-dominant sides did not differ significantly. Mechanical forces may affect the nail configuration and could participate in the pathophysiology of nail deformities.

  3. NREL Gearbox Reliability Collaborative Experimental Data Overview and Analysis: Preprint

    SciTech Connect

    Oyague, F.; Gorman, D.; Sheng, S.

    2010-05-01

    Most turbines in the market today follow a modular configuration comprised of a main shaft, gearbox, high speed shaft, and generator. The gearbox has the important task of increasing the slow rotor speeds to meet the electromechanical requirements of the electromechanical. These gearboxes are commonly composed of a planetary stage and several parallel shaft stages. The planetary, or epicyclical, design of the gearbox is a feature of the design that has many advantages compared to the traditional parallel shaft arrangement. Among these are that higher gear ratios can be achieved in a single stage, they are capable to carrying higher loads, and they require less space than the traditional parallel shaft arrangement. For this reason, planetary gearboxes they are commonly used in the first stage of the wind turbine gearboxes. However, planetary stages are more complex than the typical parallel shaft arrangement, and can be affected by deflection in the planet carrier, annulus deformations and bearing clearances. Unanticipated levels of these motions can reduce their life expectancy. This paper gives a brief overview of a subset of the experimental efforts, data, and analysis of the GRC project focusing on the planet carrier deformation.

  4. Radiation analysis of various vehicle and payload configurations for the reusable nuclear shuttle

    NASA Technical Reports Server (NTRS)

    Preeg, W. E.

    1972-01-01

    Radiation analyses were performed and shielding weight requirements were estimated for various candidate vehicle and payload configurations for use with the reusable nuclear shuttle. The analyses included both point kernel and Monte Carlo approaches. The effects on reduced shield weight were determined for propellant ranks with pointed conical tank bottoms and for one case of a cluster of small tanks. This later case, however, had an arrangement which had no center tank in the upper tier of tanks. This effect negated most of the gain of going to the smaller tanks. A range of shield weights is presented for various light and heavy manned payload configurations when used in conjunction with a single liquid hydrogen propellant tank, 33 ft in diameter with a 15 deg conical tank bottom.

  5. Analysis of electronic properties of different configurations of CNTS with undoped and doped atom

    SciTech Connect

    Sharma, Varshali

    2016-04-13

    In this paper three types of carbon nanotubes, namely, zigzag (n, 0), armchair (n= m), and chiral (n, m) are investigated with and without doping using simulation technique. The electronic properties like band structure and density of states of these three configurations with different values of n and m vectors are analysed and compared using Atomistix Toolkit (ATK) software. When the band structures of the designed configurations, reported in this paper are compared, it is observed that when the value of (n-m) vector is divisible by three, the CNTs behave as metals, otherwise they behave as semiconductors. The density of states of carbon nanotubes depicts the energy gap around the Fermi level. For the tube with chiral chirality, density of states is zero near the Fermi level, for semiconductor behaviour there is small gap in density of states near Fermi level and gap increases as the behaviour changes to insulator.

  6. Pitch difference and belt tooth configuration effect on load distribution of timing belt using FEM analysis

    SciTech Connect

    Uchida, Takanao; Furukawa, Yoshihisa; Tomono, Kiyohisa; Takahashi, Hideaki

    1996-09-01

    A timing belt used for an automotive engine`s camshaft consists of a facing fabric, elastoeric body and glass fiber cords. These materials show significant non-linear characteristics. Therefore, a model of the timing belt was analyzed using ABAQUS (a general non-linear finite element program). As a result, the mechanism that generates the belt load distribution was successfully confirmed by calculation. It was found that the pitch difference existing between the timing belt and pulley, and belt tooth configuration both have a large affect on load distribution of toothed belts. This paper reports the development of an analytical model which shows the effects of pitch difference and pulley tooth configuration on belt contact pressure.

  7. Aerothermal loads analysis for high speed flow over a quilted surface configuration

    NASA Astrophysics Data System (ADS)

    Olsen, G. C.; Smith, R. E.

    1984-08-01

    Attention is given to hypersonic laminar flow over a quilted surface configuration that simulates an array of Space Shuttle Thermal Protection System panels bowed in a spherical shape as a result of thermal gradient through the panel thickness. Pressure and heating loads to the surface are determined. The flow field over the configuration was mathematically modeled by means of time-dependent, three-dimensional conservation of mass, momentum, and energy equations. A boundary mapping technique was then used to obtain a rectangular, parallel piped computational domain, and an explicit MacCormack (1972) explicit time-split predictor corrector finite difference algorithm was used to obtain steady state solutions. Total integrated heating loads vary linearly with bowed height when this value does not exceed the local boundary layer thickness.

  8. Sensitivity analysis of upstream plasma condition for SST-1 X-Divertor configuration with SOLPS

    NASA Astrophysics Data System (ADS)

    Himabindu, M.; Tyagi, Anil K.; Sharma, Deepti; Sharma, Devendra; Srinivasan, R.

    2017-04-01

    Extensive power exhausts and target heat loads are anticipated in reactor grade fusion devices. Prototyping of an X-Divertor based power exhaust scheme is being attempted by means of simulations of Scrape-off Layer plasma transport in the diverted plasma equilibria of SST-1 tokamak using SOLPS5.1. Evaluation of the relative advantages of an X-Divertor configuration involves simulating the SST-1 standard divertor scheme plasma transport for the reference and then achieving equivalent upstream plasma conditions in the X-divertor equilibrium to ensure equivalent core plasma in both the cases. The first optimization is to be achieved by simulating effects of an external gas puff in the SOL region for controlling separatrix density in the X-divertor configuration with visible modifications in the downstream plasma conditions. The present work analyzes sensitivity of the upstream SOL plasma conditions to the gas puff intensity and its effect on the plasma neutral transport in the divertor region

  9. Analysis of Radiant Cooling System Configurations Integrated with Cooling Tower for Different Indian Climatic Zones

    SciTech Connect

    Mathur, Jyotirmay; Bhandari, Mahabir S; Jain, Robin; Srivastava, Prateek

    2016-01-01

    Radiant cooling system has proven to be a low energy consumption system for building cooling needs. This study describes the use of cooling tower in radiant cooling system to improve the overall system efficiency. A comprehensive simulation feasibility study of the application of cooling tower in radiant cooling system was performed for the fifteen cities in different climatic zones of India. It was found that in summer, the wet bulb temperature (WBT) of the different climatic zones except warm-humid is suitable for the integration of cooling tower with radiant cooling system. In these climates, cooling tower can provide on average 24 C to 27 C water In order to achieve the energy saving potential, three different configurations of radiant cooling system have been compared in terms of energy consumption. The different configurations of the radiant cooling system integrated with cooling tower are: (1) provide chilled water to the floor, wall and ceiling mounted tubular installation. (2) provide chilled water to the wall and ceiling mounted tabular installation. In this arrangement a separate chiller has also been used to provide chilled water at 16 C to the floor mounted tubular installation. (3) provide chilled water to the wall mounted tabular installation and a separate chiller is used to provide chilled water at 16 C to the floor and ceiling mounted tabular installation. A dedicated outdoor air system is also coupled for dehumidification and ventilation in all three configurations. A conventional all-air system was simulated as a baseline to compare these configurations for assessing the energy saving potential.

  10. Analysis of pronuclear zygote configurations in 459 clinical pregnancies obtained with assisted reproductive technique procedures

    PubMed Central

    2010-01-01

    Background Embryos selection is crucial to maintain high performance in terms of pregnancy rate, reducing the risk of multiple pregnancy during IVF. Pronuclear and nucleolar characteristics have been proposed as an indicator of embryo development and chromosomal complement in humans, providing information about embryo viability. Methods To correlate the zygote-score with the maternal age and the outcome of pregnancy, we analyzed the pronuclear and nucleolar morphology, the polar body alignment and the zygote configuration in 459 clinical pregnancies obtained by IVF and ICSI in our public clinic in Reggio Emilia, Italy. We derived odds ratios (OR) and Corenfield's 95% confidence intervals (CI). Continuous variables were compared with Student's t-test; P lower than .05 was considered statistically significant. Results We observed a significant increase of "A" pronuclear morphology configuration in 38-41 years old patients in comparison to that lower than or equal to 32 years old and a significant decrease of "B" configuration in 38-41 years old patients in comparison to that lower than or equal to 32 and in comparison to that of 33-37 years old. Related to maternal age we found no significant differences in P1 and in P2 configuration. We found no correlation between zygote-score, embryo cleavage and embryo quality. Conclusions Our results confirm the limited clinical significance of zygote-score suggesting that it can not be associated with maternal age, embryo cleavage and embryo quality. The evaluation of embryo quality based on morphological parameters is probably more predictive than zygote-score. PMID:20579351

  11. A finite element analysis of configurational stability and finite growth of buckling driven delamination

    NASA Astrophysics Data System (ADS)

    Nilsson, Karl-Fredrik; Giannakopoulos, Antonios E.

    1995-12-01

    A theoretical study of a budding-driven, initially circular, delaminated thin film loaded in equal bi-axial compression is presented. The main objective of this investigation is to study the configurational instability phenomena frequently observed for thin debonded coatings loaded in compression. The analyses are done with the aid of a kinematically non-linear finite element formulation of the plate problem to model the film, supplemented with a method to account automatically for the redistribution of the stress field as the shape of the advancing delamination is changing. By this procedure, not only the shape of the delaminated film but also the stability properties of the growth follow automatically. The configurational stability properties of the initially circular delamination are assessed by slightly perturbing the delamination front. The configurational instability is strongly related to the fracture mode dependence in the crack growth law. Finite growth of the buckling-driven thin film was also investigated. A load perturbation was employed as well as a front perturbation. It was found that the two perturbation methods can result in quite different shapes of the advancing buckled thin film. A few examples of extensive growth are also presented, and in some cases it was observed that a part of the delamination front may start tunnelling in the interface.

  12. Configuration Analysis of the ERS Points in Large-Volume Metrology System.

    PubMed

    Jin, Zhangjun; Yu, Cijun; Li, Jiangxiong; Ke, Yinglin

    2015-09-22

    In aircraft assembly, multiple laser trackers are used simultaneously to measure large-scale aircraft components. To combine the independent measurements, the transformation matrices between the laser trackers' coordinate systems and the assembly coordinate system are calculated, by measuring the enhanced referring system (ERS) points. This article aims to understand the influence of the configuration of the ERS points that affect the transformation matrix errors, and then optimize the deployment of the ERS points to reduce the transformation matrix errors. To optimize the deployment of the ERS points, an explicit model is derived to estimate the transformation matrix errors. The estimation model is verified by the experiment implemented in the factory floor. Based on the proposed model, a group of sensitivity coefficients are derived to evaluate the quality of the configuration of the ERS points, and then several typical configurations of the ERS points are analyzed in detail with the sensitivity coefficients. Finally general guidance is established to instruct the deployment of the ERS points in the aspects of the layout, the volume size and the number of the ERS points, as well as the position and orientation of the assembly coordinate system.

  13. Biomechanical Analysis of a Pedicle Screw-Rod System with a Novel Cross-Link Configuration

    PubMed Central

    Hara, Masahito; Umebayashi, Daisuke; Haimoto, Shoichi; Yamamoto, Yu; Nishimura, Yusuke; Wakabayashi, Toshihiko

    2016-01-01

    Study Design The strength effects of a pedicle screw-rod system supplemented with a novel cross-link configuration were biomechanically evaluated in porcine spines. Purpose To assess the biomechanical differences between a conventional cross-link pedicle screw-rod system versus a novel cross-link instrumentation, and to determine the effect of the cross-links. Overview of Literature Transverse cross-link systems affect torsional rigidity, but are thought to have little impact on the sagittal motion of spinal constructs. We tested the strength effects in pullout and flexion-compression tests of novel cross-link pedicle screw constructs using porcine thoracic and lumbar vertebrae. Methods Five matched thoracic and lumbar vertebral segments from 15 porcine spines were instrumented with 5.0-mm pedicle screws, which were then connected with 6.0-mm rods after partial corpectomy in the middle vertebral body. The forces required for construct failure in pullout and flexion-compression tests were examined in a randomized manner for three different cross-link configurations: un-cross-link control, conventional cross-link, and cross-link passing through the base of the spinous process. Statistical comparisons of strength data were analyzed using Student's t-tests. Results The spinous process group required a significantly greater pullout force for construct failure than the control group (p=0.036). No difference was found between the control and cross-link groups, or the cross-link and spinous process groups in pullout testing. In flexion-compression testing, the spinous processes group required significantly greater forces for construct failure than the control and cross-link groups (p<0.001 and p=0.003, respectively). However, there was no difference between the control and cross-link groups. Conclusions A novel cross-link configuration that features cross-link devices passing through the base of the spinous processes increased the mechanical resistance in pullout and

  14. Parametric Flutter Analysis of the TCA Configuration and Recommendation for FFM Design and Scaling

    NASA Technical Reports Server (NTRS)

    Baker, Myles; Lenkey, Peter

    1997-01-01

    The current HSR Aeroelasticity plan to design, build, and test a full span, free flying transonic flutter model in the TDT has many technical obstacles that must be overcome for a successful program. One technical obstacle is the determination of a suitable configuration and point in the sky to use in setting the scaling point for the ASE models program. Determining this configuration and point in the sky requires balancing several conflicting requirements, including model buildability, tunnel test safety, and the ability of the model to represent the flutter mechanisms of interest. As will be discussed in detail in subsequent sections, the current TCA design exhibits several flutter mechanisms of interest. It has been decided that the ASE models program will focus on the low frequency symmetric flutter mechanism, and will make no attempt to investigate high frequency flutter mechanisms. There are several reasons for this choice. First, it is believed that the high frequency flutter mechanisms are similar in nature to classical wing bending/torsion flutter, and therefore there is more confidence that this mechanism can be predicted using current techniques. The low frequency mode, on the other hand, is a highly coupled mechanism involving wing, body, tail, and engine motion which may be very difficult to predict. Second, the high frequency flutter modes result in very small weight penalties (several hundred pounds), while suppression of the low frequency mechanism inside the flight envelope causes thousands of pounds to be added to the structure. In order to successfully test the low frequency flutter mode of interest, a suitable starting configuration and point in the sky must be identified. The configuration and point in the sky must result in a wind tunnel model that (1) represents the low-frequency wing/body/engine/empennage flutter mechanisms that are unique to HSCT configurations, (2) flutters at an acceptably low frequency in the tunnel, (3) flutters at an

  15. The Analysis and Design of Two-Element Airfoil Configurations in Transonic Flow.

    DTIC Science & Technology

    1981-10-01

    Experimental Surface Pressure Distribution: NACA 64A010 Airfoil With 18A Slat; M_,z 0.7, a = 6", Re = 7.8 x 106• 26 14 Computed and Experimental Surface...separated flow. In Fig. 13, the computed pressure distribution and the experimental data (Ref 17) for an NACA 64A010 airfoil with a slat at M = 0.7, 0 60 and...T) Fig. 13 Computed and Experimental Surface Pressure Distributions: NACA 64A010 Airfoil With 18A Slat; M = 0.7. c = 60, Re = 7.8 x 10 26 II The

  16. Comparison of Experimental Data and Computations Fluid Dynamics Analysis for a Three Dimensional Linear Plug Nozzle

    NASA Technical Reports Server (NTRS)

    Ruf, J. H.; Hagemann, G.; Immich, H.

    2003-01-01

    A three dimensional linear plug nozzle of area ratio 12.79 was designed by EADS Space Transportation (former Astrium Space Infrastructure). The nozzle was tested within the German National Technology Program 'LION' in a cold air wind tunnel by TU Dresden. The experimental hardware and test conditions are described. Experimental data was obtained for the nozzle without plug side wall fences at a nozzle pressure ratio of 116 and then with plug side wall fences at NPR 110. Schlieren images were recorded and axial profiles of plug wall static pressures were measured at several spanwise locations and on the plug base. Detailed CFD analysis was performed for these nozzle configurations at NPR 116 by NASA MSFC. The CFD exhibits good agreement with the experimental data. A detailed comparison of the CFD results and the experimental plug wall pressure data are given. Comparisons are made for both the without and with plug side wall fence configurations. Numerical results for density gradient are compared to experimental Schlieren images. Experimental nozzle thrust efficiencies are calculated based on the CFD results. The CFD results are used to illustrate the plug nozzle fluid dynamics. The effect of the plug side wall is emphasized.

  17. Comparison of Experimental Data and Computations Fluid Dynamics Analysis for a Three Dimensional Linear Plug Nozzle

    NASA Technical Reports Server (NTRS)

    Ruf, J. H.; Hagemann, G.; Immich, H.

    2003-01-01

    A three dimensional linear plug nozzle of area ratio 12.79 was designed by Astrium. The nozzle was tested within the German National Technology Program LION in a cold air wind tunnel by TU Dresden. The experimental hardware and test conditions are described. Experimental data was obtained for the nozzle without plug side wall fences and then with plug side wall fences. Experimental data for two nozzle pressure ratios (NPR), 116 and 45, are presented for the without fence and with fence configurations. Schlieren images of both NPR were recorded. Axial profiles of plug wall static pressures were measured at several spanwise locations and on the plug base. Detailed computational fluid dynamics (CFD) analysis was performed for these nozzle configurations by NASA MSFC. The CFD exhibits good agreement with the experimental data. A detailed comparison of the CFD results and the experimental plug wall pressure data is given for four test conditions; at both NPRs, without and with plug side wall fences. Numerical schlieren images are compared to experimental schlieren images. Nozzle thrust efficiencies are calculated from the CFD results. The CFD results are used to illustrate the plug nozzle fluid dynamics for all four test conditions. The effect of the plug side wall fences at both NPRs is emphasized.

  18. Digital imaging techniques in experimental stress analysis

    NASA Technical Reports Server (NTRS)

    Peters, W. H.; Ranson, W. F.

    1982-01-01

    Digital imaging techniques are utilized as a measure of surface displacement components in laser speckle metrology. An image scanner which is interfaced to a computer records and stores in memory the laser speckle patterns of an object in a reference and deformed configuration. Subsets of the deformed images are numerically correlated with the references as a measure of surface displacements. Discrete values are determined around a closed contour for plane problems which then become input into a boundary integral equation method in order to calculate surface traction in the contour. Stresses are then calculated within this boundary. The solution procedure is illustrated by a numerical example of a case of uniform tension.

  19. Transonic Free-To-Roll Analysis of the F/A-18E and F-35 Configurations

    NASA Technical Reports Server (NTRS)

    Owens, D. Bruce; McConnell, Jeffrey K.; Brandon, Jay M.; Hall, Robert M.

    2004-01-01

    The free-to-roll technique is used as a tool for predicting areas of uncommanded lateral motions. Recently, the NASA/Navy/Air Force Abrupt Wing Stall Program extended the use of this technique to the transonic speed regime. Using this technique, this paper evaluates various wing configurations on the pre-production F/A-18E aircraft and the Joint Strike Fighter (F-35) aircraft. The configurations investigated include leading and trailing edge flap deflections, fences, leading edge flap gap seals, and vortex generators. These tests were conducted in the NASA Langley 16-Foot Transonic Tunnel. The analysis used a modification of a figure-of-merit developed during the Abrupt Wing Stall Program to discern configuration effects. The results showed how the figure-of-merit can be used to schedule wing flap deflections to avoid areas of uncommanded lateral motion. The analysis also used both static and dynamic wind tunnel data to provide insight into the uncommanded lateral behavior. The dynamic data was extracted from the time history data using parameter identification techniques. In general, modifications to the pre-production F/A-18E resulted in shifts in angle-of-attack where uncommanded lateral activity occurred. Sealing the gap between the inboard and outboard leading-edge flaps on the Navy version of the F-35 eliminated uncommanded lateral activity or delayed the activity to a higher angle-of-attack.

  20. Analysis of UAV state estimation modeling based on AHRS and INS configurations

    NASA Astrophysics Data System (ADS)

    Razali, Shikin; Zhahir, Amzari

    2017-09-01

    State estimation for unmanned aerial vehicle is one of the important components in autonomous UAV. There are several techniques and algorithms used in estimating UAV states depend on the applied sensors. Inertial measurement unit (IMU) based attitude heading and reference system (AHRS) and complete inertial navigation system (INS) are the common navigation sensors used for UAV today. The differences between these two configurations in estimating UAV states are analyzed in this paper using state estimation modeling in Matlab environment. The results are displayed through UAV position and attitude graphs.

  1. An arbitrary grid CFD algorithm for configuration aerodynamics analysis. Volume 1: Theory and validations

    NASA Technical Reports Server (NTRS)

    Baker, A. J.; Iannelli, G. S.; Manhardt, Paul D.; Orzechowski, J. A.

    1993-01-01

    This report documents the user input and output data requirements for the FEMNAS finite element Navier-Stokes code for real-gas simulations of external aerodynamics flowfields. This code was developed for the configuration aerodynamics branch of NASA ARC, under SBIR Phase 2 contract NAS2-124568 by Computational Mechanics Corporation (COMCO). This report is in two volumes. Volume 1 contains the theory for the derived finite element algorithm and describes the test cases used to validate the computer program described in the Volume 2 user guide.

  2. Development and benefit analysis of a sector design algorithm for terminal dynamic airspace configuration

    NASA Astrophysics Data System (ADS)

    Sciandra, Vincent

    The National Airspace System (NAS) is the vast network of systems enabling safe and efficient air travel in the United States. It consists of a set of static sectors, each controlled by one or more air traffic controllers. Air traffic control is tasked with ensuring that all flights can depart and arrive on time and in a safe and efficient matter. However, skyrocketing demand will only increase the stress on an already inefficient system, causing massive delays. The current, static configuration of the NAS cannot possibly handle the future demand on the system safely and efficiently, especially since it is projected to triple by 2025. To overcome these issues, the Next Generation of Air Transportation System (NextGen) is being enacted to increase the flexibility of the NAS. A major objective of NextGen is to implement Adaptable Dynamic Airspace Configuration (ADAC) which will dynamically allocate the sectors to best fit the traffic in the area. Dynamically allocating sectors will allow resources such as controllers to be better distributed to meet traffic demands. Currently, most DAC research has involved the en route airspace. This leaves the terminal airspace, which accounts for a large amount of the overall NAS complexity, in need of work. Using a combination of methods used in en route sectorization, this thesis has developed an algorithm for the dynamic allocation of sectors in the terminal airspace. This algorithm will be evaluated using metrics common in the evaluation of dynamic density, which is adapted for the unique challenges of the terminal airspace, and used to measure workload on air traffic controllers. These metrics give a better view of the controller workload than the number of aircraft alone. By comparing the test results with sectors currently used in the NAS using real traffic data, the algorithm xv generated sectors can be quantitatively evaluated for improvement of the current sectorizations. This will be accomplished by testing the

  3. An arbitrary grid CFD algorithm for configuration aerodynamics analysis. Volume 2: FEMNAS user guide

    NASA Technical Reports Server (NTRS)

    Manhardt, Paul D.; Orzechowski, J. A.; Baker, A. J.

    1992-01-01

    This report documents the user input and output data requirements for the FEMNAS finite element Navier-Stokes code for real-gas simulations of external aerodynamics flowfields. This code was developed for the configuration aerodynamics branch of NASA ARC, under SBIR Phase 2 contract NAS2-124568 by Computational Mechanics Corporation (COMCO). This report is in two volumes. Volume 1 contains the theory for the derived finite element algorithm and describes the test cases used to validate the computer program described in the Volume 2 user guide.

  4. Numerical and Experimental Study of Mixing Properties of Gaseous Fuels Jets Including Hydrogen and Methane Into the non-Swirl Main Flow in a Premixer Configuration

    NASA Astrophysics Data System (ADS)

    Akbari, Amin

    The mixing of fuel and air has a significant impact on overall operation efficiency and emissions performance of combustion systems, especially in lean combustion applications. As a result, developing an understanding of the processes associated with the fuel/air mixing is important. In parallel with the evolution of lean combustion, a new generation of fuels is emerging as an alternative to conventional fuels. Thus, it is desirable to study the mixing properties of different fuels from conventional resources, such as methane, as well as from renewable resources, such as hydrogen. One tool that is available to study mixing in complex (e.g., turbulent and elliptic) flows is computational fluid dynamics (CFD). In the present work, mixing of hydrogen and methane into air, for example, is simulated using various CFD approaches. Fuel is injected either co-flowing to the air flow ("axial injection") or perpendicular to the air flow ("radial injection"). The quality of the simulations is evaluated by comparing the numerical results with experimental measurements. Qualitative and quantitative comparisons are used to evaluate the relative accuracy of different CFD approaches to simulate the mixing characteristics. Reynolds Averaged Navier-Stokes (RANS) turbulent models are utilized to model all the cases as steady turbulent models. Moreover, unsteady turbulent models, such as Unsteady RANS, and Large Eddy Simulation (LES) are used to provide information about unsteady features in selected cases. The sensitivity of numerical predictions to different RANS turbulence models as well as to different turbulent Schmidt numbers are explored. The results indicate more sensitivity to turbulence models for radial injection configurations. However, for the axial configuration, more sensitivity to Sct is observed. In general, the RSM turbulence model with Sc t=0.7 provides the most promising predictions for various combination of different fuels and injection types.

  5. Experimental aerodynamic characteristics of a generic hypersonic accelerator configuration at Mach numbers 1.5 and 2.0. [conducted in the Langley Unitary Plan Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Walker, Ira J.; Covell, Peter F.; Forrest, Dana K.

    1993-01-01

    An experimental investigation of the static longitudinal and lateral-directional aerodynamic characteristics of a generic hypersonic research vehicle was conducted in the Langley Unitary Plan Wind Tunnel (UPWT). A parametric study was performed to determine the interference effects of various model components. Configuration variables included delta and trapezoidal canards; large and small centerline-mounted vertical tails, along with a set of wing-mounted vertical tails; and a set of model noses with different degrees of bluntness. Wing position was varied by changing the longitudinal location and the incidence angle. The test Mach numbers were 1.5 and 2.0 at Reynolds numbers of 1 x 10(exp 6) per foot, 2 x 10(exp 6) per foot, and 4 x 10(exp 6) per foot. Angle of attack was varied from -4 degrees to 27 degrees, and sideslip angle was varied from -8 degrees to 8 degrees. Generally, the effect of Reynolds number did not deviate from conventional trends. The longitudinal stability and lift-curve slope decreased with increasing Mach number. As the wing was shifted rearward, the lift-curve slope decreased and the longitudinal stability increased. Also, the wing-mounted vertical tails resulted in a more longitudinally stable configuration. In general, the lift-drag ratio was not significantly affected by vertical-tail arrangement. The best lateral-directional stability was achieved with the large centerline-mounted tail, although the wing-mounted vertical tails exhibited the most favorable characteristics at the higher angles of attack.

  6. Performance Analysis of Two Early NACA High Speed Propellers with Application to Civil Tiltrotor Configurations

    NASA Technical Reports Server (NTRS)

    Harris, Franklin D.

    1996-01-01

    The helicopter industry is vigorously pursuing development of civil tiltrotors. One key to efficient high speed performance of this rotorcraft is prop-rotor performance. Of equal, if not greater, importance is assurance that the flight envelope is free of aeroelastic instabilities well beyond currently envisioned cuise speeds. This later condition requires study at helical tip Match numbers well in excess of 1.0. Two 1940's 'supersonic' propeller experiments conducted by NACA have provided an immensely valuable data bank with which to study prop-rotor behavior at transonic and supersonic helical tip Mach numbers. Very accurate 'blades alone' data were obtained by using nearly an infinite hub. Tabulated data were recreated from the many thrust and power figures and are included in two Appendices to this report. This data set is exceptionally well suited to re-evaluating classical blade element theories as well as evolving computational fluid dynamic (CFD) analyses. A limited comparison of one propeller's experimental results to a modem rotorcraft CFD code is made. This code, referred to as TURNS, gives very encouraging results. Detailed analysis of the performance data from both propellers is provided in Appendix A. This appendix quantifies the minimum power required to produce usable prop-rotor thrust. The dependence of minimum profile power on Reynolds number is quantified. First order compressibility power losses are quantified as well and a first approximation to design air-foil thickness ratio to avoid compressibility losses is provided. Appendix A's results are applied to study high speed civil tiltrotor cruise performance. Predicted tiltrotor performance is compared to two turboprop commercial transports. The comparison shows that there is no fundamental aerodynamic reason why the rotorcraft industry could not develop civil tiltrotor aircraft which have competitive cruise performance with today's regional, turboprop airlines. Recommendations for future study

  7. Determination of the absolute configuration of (+)-neopentyl-1-d alcohol by neutron and x-ray diffraction analysis

    SciTech Connect

    Yuan, H.S.H.; Stevens, R.C.; Bau, R. ); Mosher, H.S. ); Koetzle, T.F. )

    1994-12-20

    The absolute configuration of (+)-neopentyl-1-d alcohol, prepared by the reduction of 2,2-dimethylpropanol-1-d by actively fermenting yeast, has been determined to be S by neutron diffraction. The neutron study was carried out on the phthalate half ester of neopentyl-1-d alcohol, crystallized as its strychnine salt. The absolute configuration of the (-)-strychninium cation was first determined by an x-ray anomalous dispersion study of its iodide salt. The chiral skeleton of strychnine then served as a reference from which the absolute configuration of the -O-CHD-C(CH[sub 3])[sub 3] group of neopentyl phthalate was determined. Difference Fourier maps calculated from the neutron data showed unambiguously that the -O-CHD-C(CH[sub 3])[sub 3] groups of both independent molecules in the unit cell had the S configuration. This work proves conclusively that the yeast system reduces aldehydes by delivering hydrogen to the re face of the carbonyl group. Crystallographic details: (-)-strychninium (+)-neopentyl-1-d phthalate, space group P2[sub 1] (monoclinic), a = 18.564(6) [angstrom], b = 7.713(2) [angstrom], c = 23.361(8) [angstrom], [beta] = 94.18(4)[degrees], V = 3336.0(5) [angstrom][sup 3], Z = 2 (T = 100 K). Final agreement factors are R(F) = 0.073 for 2768 reflections collected at room temperature (x-ray analysis) and R(F) = 0.144 for 960 reflections collected at 100 K (neutron analysis). 49 refs., 7 figs., 2 tabs.

  8. Geometric analysis characterizes molecular rigidity in generic and non-generic protein configurations.

    PubMed

    Budday, Dominik; Leyendecker, Sigrid; van den Bedem, Henry

    2015-10-01

    Proteins operate and interact with partners by dynamically exchanging between functional substates of a conformational ensemble on a rugged free energy landscape. Understanding how these substates are linked by coordinated, collective motions requires exploring a high-dimensional space, which remains a tremendous challenge. While molecular dynamics simulations can provide atomically detailed insight into the dynamics, computational demands to adequately sample conformational ensembles of large biomolecules and their complexes often require tremendous resources. Kinematic models can provide high-level insights into conformational ensembles and molecular rigidity beyond the reach of molecular dynamics by reducing the dimensionality of the search space. Here, we model a protein as a kinematic linkage and present a new geometric method to characterize molecular rigidity from the constraint manifold Q and its tangent space Q at the current configuration q. In contrast to methods based on combinatorial constraint counting, our method is valid for both generic and non-generic, e.g., singular configurations. Importantly, our geometric approach provides an explicit basis for collective motions along floppy modes, resulting in an efficient procedure to probe conformational space. An atomically detailed structural characterization of coordinated, collective motions would allow us to engineer or allosterically modulate biomolecules by selectively stabilizing conformations that enhance or inhibit function with broad implications for human health.

  9. Finite Element Analysis of Composite Joint Configurations with Gaps and Overlaps

    NASA Technical Reports Server (NTRS)

    Krueger, Ronald

    2014-01-01

    The goal of the current study is to identify scenarios for which thermal and moisture effects become significant in the loading of a composite structure. In the current work, a simple configuration was defined, and material properties were selected. A Fortran routine was created to automate the mesh generation process. The routine was used to create the models for the initial mesh refinement study. A combination of element length and width suitable for further studies was identified. Also, the effect of the overlap length and gap length on computed shear and through-thickness stresses along the bondline of the joints was studied for the mechanical load case. Further, the influence of neighboring gaps and overlaps on these joint stresses was studied and was found to be negligible. The results suggest that for an initial study it is sufficient to focus on one configuration with fixed overlap and gap lengths to study the effects of mechanical, thermal and moisture loading and combinations thereof on computed joint stresses

  10. Numerical analysis of flow in ultra micro centrifugal compressor -influence of meridional configuration

    NASA Astrophysics Data System (ADS)

    Kaneko, Masanao; Tsujita, Hoshio; Hirano, Toshiyuki

    2013-04-01

    A single stage ultra micro centrifugal compressor constituting ultra micro gas turbine is required to operate at high rotational speed in order to achieve the pressure ratio which establishes the gas turbine cycle. As a consequence, the aerodynamic losses can be increased by the interaction of a shock wave with the boundary layer on the blade surface. Moreover, the centrifugal force which exceeds the allowable stress of the impeller material can act on the root of blades. On the other hand, the restrictions of processing technology for the downsizing of impeller not only relatively enlarge the size of tip clearance but also make it difficult to shape the impeller with the three-dimensional blade. Therefore, it is important to establish the design technology for the impeller with the two-dimensional blade which possesses the sufficient aerodynamic performance and enough strength to bear the centrifugal force caused by the high rotational speed. In this study, the flow in two types of impeller with the two-dimensional blade which have different meridional configuration was analyzed numerically. The computed results clarified the influence of the meridional configuration on the loss generations in the impeller passage.

  11. Geometric analysis characterizes molecular rigidity in generic and non-generic protein configurations

    PubMed Central

    Budday, Dominik; Leyendecker, Sigrid; van den Bedem, Henry

    2015-01-01

    Proteins operate and interact with partners by dynamically exchanging between functional substates of a conformational ensemble on a rugged free energy landscape. Understanding how these substates are linked by coordinated, collective motions requires exploring a high-dimensional space, which remains a tremendous challenge. While molecular dynamics simulations can provide atomically detailed insight into the dynamics, computational demands to adequately sample conformational ensembles of large biomolecules and their complexes often require tremendous resources. Kinematic models can provide high-level insights into conformational ensembles and molecular rigidity beyond the reach of molecular dynamics by reducing the dimensionality of the search space. Here, we model a protein as a kinematic linkage and present a new geometric method to characterize molecular rigidity from the constraint manifold Q and its tangent space Q at the current configuration q. In contrast to methods based on combinatorial constraint counting, our method is valid for both generic and non-generic, e.g., singular configurations. Importantly, our geometric approach provides an explicit basis for collective motions along floppy modes, resulting in an efficient procedure to probe conformational space. An atomically detailed structural characterization of coordinated, collective motions would allow us to engineer or allosterically modulate biomolecules by selectively stabilizing conformations that enhance or inhibit function with broad implications for human health. PMID:26213417

  12. Analysis of electric energy consumption of automatic milking systems in different configurations and operative conditions.

    PubMed

    Calcante, Aldo; Tangorra, Francesco M; Oberti, Roberto

    2016-05-01

    Automatic milking systems (AMS) have been a revolutionary innovation in dairy cow farming. Currently, more than 10,000 dairy cow farms worldwide use AMS to milk their cows. Electric consumption is one of the most relevant and uncontrollable operational cost of AMS, ranging between 35 and 40% of their total annual operational costs. The aim of the present study was to measure and analyze the electric energy consumption of 4 AMS with different configurations: single box, central unit featuring a central vacuum system for 1 cow unit and for 2 cow units. The electrical consumption (daily consumption, daily consumption per cow milked, consumption per milking, and consumption per 100L of milk) of each AMS (milking unit + air compressor) was measured using 2 energy analyzers. The measurement period lasted 24h with a sampling frequency of 0.2Hz. The daily total energy consumption (milking unit + air compressor) ranged between 45.4 and 81.3 kWh; the consumption per cow milked ranged between 0.59 and 0.99 kWh; the consumption per milking ranged between 0.21 and 0.33 kWh; and the consumption per 100L of milk ranged between 1.80 to 2.44 kWh according to the different configurations and operational contexts considered. Results showed that AMS electric consumption was mainly conditioned by farm management rather than machine characteristics/architectures. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  13. Geometric analysis characterizes molecular rigidity in generic and non-generic protein configurations

    NASA Astrophysics Data System (ADS)

    Budday, Dominik; Leyendecker, Sigrid; van den Bedem, Henry

    2015-10-01

    Proteins operate and interact with partners by dynamically exchanging between functional substates of a conformational ensemble on a rugged free energy landscape. Understanding how these substates are linked by coordinated, collective motions requires exploring a high-dimensional space, which remains a tremendous challenge. While molecular dynamics simulations can provide atomically detailed insight into the dynamics, computational demands to adequately sample conformational ensembles of large biomolecules and their complexes often require tremendous resources. Kinematic models can provide high-level insights into conformational ensembles and molecular rigidity beyond the reach of molecular dynamics by reducing the dimensionality of the search space. Here, we model a protein as a kinematic linkage and present a new geometric method to characterize molecular rigidity from the constraint manifold Q and its tangent space Tq Q at the current configuration q. In contrast to methods based on combinatorial constraint counting, our method is valid for both generic and non-generic, e.g., singular configurations. Importantly, our geometric approach provides an explicit basis for collective motions along floppy modes, resulting in an efficient procedure to probe conformational space. An atomically detailed structural characterization of coordinated, collective motions would allow us to engineer or allosterically modulate biomolecules by selectively stabilizing conformations that enhance or inhibit function with broad implications for human health.

  14. SCALE-4 Analysis of LaSalle Unit 1 BWR Commercial Reactor Critical Configurations

    SciTech Connect

    Gauld, I.C.

    2000-03-01

    Five commercial reactor criticals (CRCs) for the LaSalle Unit 1 boiling-water reactor have been analyzed using KENO V.a, the Monte Carlo criticality code of the SCALE 4 code system. The irradiated fuel assembly isotopics for the criticality analyses were provided by the Waste Package Design team at the Yucca Mountain Project in the US, who performed the depletion calculations using the SAS2H sequence of SCALE 4. The reactor critical measurements involved two beginning-of-cycle and three middle-of-cycle configurations. The CRCs involved relatively low-cycle burnups, and therefore contained a relatively high gadolinium poison content in the reactor assemblies. This report summarizes the data and methods used in analyzing the critical configurations and assesses the sensitivity of the results to some of the modeling approximations used to represent the gadolinium poison distribution within the assemblies. The KENO V.a calculations, performed using the SCALE 44GROUPNDF5 ENDF/B-V cross-section library, yield predicted k{sub eff} values within about 1% {Delta}k/k relative to reactor measurements for the five CRCs using general 8-pin and 9-pin heterogeneous gadolinium poison pin assembly models.

  15. Confocal microscopic analysis of the microfilament configurations from human vitrification-thawed oocytes matured in vitro.

    PubMed

    Ci, Qianqian; Li, Mei; Zhang, Yingchun; Ma, Shuiying; Gao, Qin; Shi, Yuhua

    2014-01-01

    The alteration in microfilaments of human oocytes by vitrification has not been understood well. To evaluate the effect of vitrification on the microfilaments of human in vitro matured oocytes and the time needed for the repair. Human in vitro matured oocytes were divided into the control group (Group 1) and the vitrified group. The vitrified oocytes were further divided into four sub-groups that were cultured after thawing for 1 h, 2 h, 3 h and 4 h, respectively (Groups 2, 3, 4 and 5). The survival rate of oocytes was 87.4% after vitrification and thawing. The percentage of oocytes with a normal configuration of microfilaments in Group 2 and Group 3 was significantly lower than that of the fresh control group (Group 1), whereas the percentage of oocytes with normal microfilament configuration in Group 4 and Group 5 was comparable to the control group. Vitrification alters microfilament structure of oocytes, which takes at least 3h after thawing for the repair and recovery.

  16. Numerical analysis of the s1020 airfoils in tandem under different flapping configurations

    NASA Astrophysics Data System (ADS)

    Lim, K. B.; Tay, W. B.

    2010-05-01

    The objective of this project is to improve the performance of the efficiency, thrust and lift of flapping wings in tandem arrangement. This research investigates the effect of the arrangement of the airfoils in tandem on the performance of the airfoils by varying the phase difference and distance between the airfoils. Three flapping configurations from an earlier phase of a research which gives high efficiency, thrust and lift are used in the tandem simulation. It is found all the different flapping configurations show improvement in the efficiency, thrust or lift when the distance between the two airfoils and the phase angle between the heaving positions of the two airfoils are optimal. The average thrust coefficient of the tandem arrangement managed to attain more than twice that of the single one (4.84 vs. 2.05). On the other hand, the average lift coefficient of the tandem arrangement also increased to 4.59, as compared to the original single airfoil value of 3.04. All these results obtained will aid in the design of a better ornithopter with tandem wing arrangement.

  17. Thermomechanical analysis of solid breeders in sphere-pac, plate, and pellet configurations

    SciTech Connect

    Blanchard, J.P.; Ghoniem, N.M.

    1986-02-01

    The first configuration studied is called sphere-pac. It features small breeder spheres of three different diameters, thus allowing efficient packing and minimal void fraction. The concept originated as an attempt to minimize thermal stresses in the breeder and improve the predictability of the breeder-structure interface heat conduction. In general the breeder is made as thin as possible, to maximize the breeding ratio, so the cladding's integrity will likely be the life-limiting issue of this concept. The third breeder configuration is in the form of pellets cladded by steel tubes. The major thermomechanical issue of the pin-type designs is cracking, which would impair the thermal performance of the blanket. Fortunately, the pins can be sized to prevent cracking under normal operation. In this report we have treated each blanket generically, dealing with basic issues rather than design specifics. Our basic philosophy is to avoid cracking of the breeder if at all possible. It can be argued that cracking could be allowed, but this would sacrifice predictability of the blanket thermal performance and tritium release characteristics. Proper design can and should minimize breeder cracking.

  18. SCALE-4 Analysis of LaSalle Unit 1 BWR Commercial Reactor Critical Configuration

    SciTech Connect

    Gauld, I.C.

    2000-03-16

    Five commercial reactor criticals (CRCs) for the LaSalle Unit 1 boiling-water reactor have been analyzed using KENO V.a, the Monte Carlo criticality code of the SCALE 4 code system. The irradiated fuel assembly isotopics for the criticality analyses were provided by the Waste Package Design team at the Yucca Mountain Project in the United States, who performed the depletion calculations using the SAS2H sequence of SCALE 4. The reactor critical measurements involved two beginning-of-cycle and three middle-of-cycle configurations. The CRCs involved relatively low-cycle burnups, and therefore contained a relatively high gadolinium poison content in the reactor assemblies. This report summarizes the data and methods used in analyzing the critical configurations and assesses the sensitivity of the results to some of the modeling approximations used to represent the gadolinium poison distribution within the assemblies. The KENO V.a calculations, performed using the SCALE 44GROUPNDF5 ENDF/B-V cross-section library, yield predicted k{sub eff} values within about 1% {Delta}k/k relative to reactor measurements for the five CRCs using general 8-pin and 9-pin heterogeneous gadolinium poison pin assembly models.

  19. Analysis and prediction of traffic fatalities resulting from angle collisions including the effect of vehicles' configuration and compatibility.

    PubMed

    Abdel-Aty, Mohamed; Abdelwahab, Hassan

    2004-05-01

    Although the rapid growth in light truck vehicle (LTV) sales, including minivans, sports utility vehicles (SUVs), and light-duty trucks, has not been associated with an overall increase in collisions or traffic deaths in the US, there is a need for a research program to determine whether particular types of collisions have become more frequent or injurious because of the increase in the percent of LTVs in traffic. This paper presents an analysis of the effect of the increasing number of LTV registrations on fatal angle collision trends in the US. The analysis investigates the number of annual fatalities that result from angle collisions as well as collision configuration (car-car, car-LTV, LTV-car, and LTV-LTV). The analysis uses the Fatality Analysis Reporting System (FARS) crash databases covering the period 1975-2000. Results showed that death rates differ based on the collision configuration. Time series modeling results showed that fatalities in angle collisions will increase in the next 10 years, and that they are affected by the expected increase in the percentage of LTVs in traffic. Forecast showed that the total number of annual deaths is expected to reach 6300 deaths by the year 2010 (an increase of 12% over 2000). Analysis into the configuration of the collision indicated the seriousness of angle collisions involving an LTV striking a common passenger car (LTV-car). A time series model illustrated the significance of time lag and percent of LTVs in traffic on the increase of this type of fatal collisions. Forecasts from the time series model indicated a 32% increase in deaths due to this type of collisions in the next 10 years.

  20. An Experimental Analysis of Another Privacy

    ERIC Educational Resources Information Center

    Okouchi, Hiroto

    2006-01-01

    The present article discusses how events outside a subject's skin and not accessible to another subject but to an experimenter may contribute to experimental analyses of private events. Of 16 undergraduates, 8, referred to as instructors, first learned conditional discriminations (i.e., B1C1, B2C2, B3C3, and B4C4) in a standard matching-to-sample…

  1. An Experimental Analysis of Another Privacy

    ERIC Educational Resources Information Center

    Okouchi, Hiroto

    2006-01-01

    The present article discusses how events outside a subject's skin and not accessible to another subject but to an experimenter may contribute to experimental analyses of private events. Of 16 undergraduates, 8, referred to as instructors, first learned conditional discriminations (i.e., B1C1, B2C2, B3C3, and B4C4) in a standard matching-to-sample…

  2. Exploratory studies of the cruise performance of upper surface blown configurations: Program analysis and conclusions

    NASA Technical Reports Server (NTRS)

    Braden, J. A.; Hancock, J. P.; Hackett, J. E.; Lyman, V.

    1979-01-01

    The experimental data encompassing surface pressure measurements, and wake surveys at static and wind-on conditions are analyzed. Cruise performance trends reflecting nacelle geometric variations, and nozzle operating conditions are presented. Details of the modeling process are included.

  3. Analysis of the Capacity Potential of Current Day and Novel Configurations for New York's John F. Kennedy Airport

    NASA Technical Reports Server (NTRS)

    Glaab, Patricia; Tamburro, Ralph; Lee, Paul

    2016-01-01

    In 2015, a series of systems analysis studies were conducted on John F. Kennedy Airport in New York (NY) in a collaborative effort between NASA and the Port Authority of New York and New Jersey (PANYNJ). This work was performed to build a deeper understanding of NY airspace and operations to determine the improvements possible through operational changes with tools currently available, and where new technology is required for additional improvement. The analysis was conducted using tool-based mathematical analyses, video inspection and evaluation using recorded arrival/departure/surface traffic captured by the Aerobahn tool (used by Kennedy Airport for surface metering), and aural data archives available publically through the web to inform the video segments. A discussion of impacts of trajectory and operational choices on capacity is presented, including runway configuration and usage (parallel, converging, crossing, shared, independent, staggered), arrival and departure route characteristics (fix sharing, merges, splits), and how compression of traffic is staged. The authorization in March of 2015 for New York to use reduced spacing under the Federal Aviation Administration (FAA) Wake Turbulence Recategorization (RECAT) also offers significant capacity benefit for New York airports when fully transitioned to the new spacing requirements, and the impact of these changes for New York is discussed. Arrival and departure capacity results are presented for each of the current day Kennedy Airport configurations. While the tools allow many variations of user-selected conditions, the analysis for these studies used arrival-priority, no-winds, additional safety buffer of 5% to the required minimum spacing, and a mix of traffic typical for Kennedy. Two additional "novel" configurations were evaluated. These configurations are of interest to Port Authority and to their airline customers, and are believed to offer near-term capacity benefit with minimal operational and

  4. Highly Efficient Design-of-Experiments Methods for Combining CFD Analysis and Experimental Data

    NASA Technical Reports Server (NTRS)

    Anderson, Bernhard H.; Haller, Harold S.

    2009-01-01

    It is the purpose of this study to examine the impact of "highly efficient" Design-of-Experiments (DOE) methods for combining sets of CFD generated analysis data with smaller sets of Experimental test data in order to accurately predict performance results where experimental test data were not obtained. The study examines the impact of micro-ramp flow control on the shock wave boundary layer (SWBL) interaction where a complete paired set of data exist from both CFD analysis and Experimental measurements By combining the complete set of CFD analysis data composed of fifteen (15) cases with a smaller subset of experimental test data containing four/five (4/5) cases, compound data sets (CFD/EXP) were generated which allows the prediction of the complete set of Experimental results No statistical difference were found to exist between the combined (CFD/EXP) generated data sets and the complete Experimental data set composed of fifteen (15) cases. The same optimal micro-ramp configuration was obtained using the (CFD/EXP) generated data as obtained with the complete set of Experimental data, and the DOE response surfaces generated by the two data sets were also not statistically different.

  5. Analysis of aeromedical retrieval coverage using elliptical isochrones: An evaluation of helicopter fleet size configurations in Scotland.

    PubMed

    Dodds, Naomi; Emerson, Philip; Phillips, Stephanie; Green, David R; Jansen, Jan O

    2017-03-01

    Trauma systems in remote and rural regions often rely on helicopter emergency medical services to facilitate access to definitive care. The siting of such resources is key, but often relies on simplistic modeling of coverage, using circular isochrones. Scotland is in the process of implementing a national trauma network, and there have been calls for an expansion of aeromedical retrieval capacity. The aim of this study was to analyze population and area coverage of the current retrieval service configuration, with three aircraft, and a configuration with an additional helicopter, in the North East of Scotland, using a novel methodology. Both overall coverage and coverage by physician-staffed aircraft, with enhanced clinical capability, were analyzed. This was a geographical analysis based on calculation of elliptical isochrones, which consider the "open-jaw" configuration of many retrieval flights. Helicopters are not always based at hospitals. We modeled coverage based on different outbound and inbound flights. Areally referenced population data were obtained from the Scottish Government. The current helicopter network configuration provides 94.2% population coverage and 59.0% area coverage. The addition of a fourth helicopter would marginally increase population coverage to 94.4% and area coverage to 59.1%. However, when considering only physician-manned aircraft, the current configuration provides only 71.7% population coverage and 29.4% area coverage, which would be increased to 91.1% and 51.2%, respectively, with a second aircraft. Scotland's current helicopter network configuration provides good population coverage for retrievals to major trauma centers, which would only be increased minimally by the addition of a fourth aircraft in the North East. The coverage provided by the single physician-staffed aircraft is more limited, however, and would be increased considerably by a second physician-staffed aircraft in the North East. Elliptical isochrones provide a

  6. Theoretical analysis of south-staring Beampark configurations for the TIRA system

    NASA Astrophysics Data System (ADS)

    Flegel, S.; Letsch, K.; Krag, H.

    2015-09-01

    The tracking and imaging radar (TIRA) L-band radar of the Fraunhofer Institute for High Frequency Physics and Radar Techniques (FHR) in Wachtberg has been used since 1993 for the conduction of space debris measurement campaigns, called Beampark experiments (BPE). The results from BPEs are used for the regular validation of statistical debris models such as ESA's MASTER model. It is an experimental radar system which is employed among other things in the frame of BPEs. In these experiments, the line-of-sight (LOS) of the radar is fixed at a defined direction and measurements are taken for 24 h. The aim of these campaigns is to obtain statistical information on the state of the space debris environment in Low Earth Orbit. BPEs are typically conducted in mono-static east-staring mode. The aim of the current paper is to gain an overview of how the measurement results of mono-static BPEs using TIRA are influenced by the direction of the LOS with a focus on south-staring BPEs. The analysis is purely theoretical and employs ESA's Program for Radar and Optical Observation Forecasting (PROOF-2009). The paper starts out with a look at the range window as a function of the LOS elevation which is required to cover LEO altitudes up to 2000 km. This information is required to determine the minimum allowed pulse repetition interval necessary to obtain unambiguous range information. In a next step, 24 h BPEs are simulated covering azimuth angles between 0° and 360° and elevation angles between 10° and 90°. Looking at the number of crossings and detections at various object sizes, orbit types and debris sources allows an assessment of specific LOS orientations. Due to the relatively high latitude of the sensor at about 50° north, debris at low inclinations can only be detected if the radar's LOS is directed due south. The lower the LOS elevation is, the more objects on low inclination orbits will cross TIRA's beam. A low LOS elevation however requires an extended range window

  7. A High-Order Method Using Unstructured Grids for the Aeroacoustic Analysis of Realistic Aircraft Configurations

    NASA Technical Reports Server (NTRS)

    Atkins, Harold L.; Lockard, David P.

    1999-01-01

    A method for the prediction of acoustic scatter from complex geometries is presented. The discontinuous Galerkin method provides a framework for the development of a high-order method using unstructured grids. The method's compact form contributes to its accuracy and efficiency, and makes the method well suited for distributed memory parallel computing platforms. Mesh refinement studies are presented to validate the expected convergence properties of the method, and to establish the absolute levels of a error one can expect at a given level of resolution. For a two-dimensional shear layer instability wave and for three-dimensional wave propagation, the method is demonstrated to be insensitive to mesh smoothness. Simulations of scatter from a two-dimensional slat configuration and a three-dimensional blended-wing-body demonstrate the capability of the method to efficiently treat realistic geometries.

  8. Performance analysis of dye solar cells with various nanoparticles-aggregates mesoscopic multilayer configurations

    NASA Astrophysics Data System (ADS)

    Samsudin, Adel Eskandar; Mohamed, Norani Muti

    2012-11-01

    Multilayers of different TiO2 aggregate-nanoparticles compositions were utilized to improve the sensitized TiO2 dye solar cells (DSC) by light confinement in the layer. Four different TiO2 aggregate-nanoparticle composite were integrated as the photoelectrode material of DSCs and their performance and physics were investigated. TiO2 pastes of different composition ratios films were screen-printed onto transparent conducting oxide (TCO) glass and assembled into test cells. I-V characterization was conducted using solar simulator. Electrochemical impedance spectroscopy (EIS) was utilized in order to measure electron transport properties. Measurement for the quantum efficiency and spectral response of the DSCs were performed using incident photon-to-electron conversion efficiency (IPCE). DSC test cell with an optimized configuration recorded the highest overall power conversion efficiency of 4.22% under the irradiation of 100 mW/cm2 of AM 1.5 simulated sunlight.

  9. Analysis on shock attenuation in gap test configuration for characterizing energetic materials

    NASA Astrophysics Data System (ADS)

    Kim, Bohoon; Park, Jungsu; Yoh, Jack J.

    2016-04-01

    A pyrotechnic system consisting of donor/acceptor pair separated by a gap relies on shock attenuation characteristics of the gap material and shock sensitivity of the donor and the acceptor charges. Despite of its common use, a numerical study of such a pyrotechnic train configuration is seldom reported because proper modeling of the full process requires precise capturing of the shock wave attenuation in the gap prior to triggering a full detonation of a high explosive and accurate description of the high strain rate dynamics of the explosively loaded inert confinements. We apply a hybrid particle level-set based multimaterial hydrocode with reactive flow models for pentolite donor and heavily aluminized cyclotrimethylene-trinitramine as the acceptor charge. The complex shock interaction, a critical gap thickness, an acoustic impedance, and go/no-go characteristics of the pyrotechnic system are quantitatively investigated.

  10. Analysis on shock attenuation in gap test configuration for characterizing energetic materials

    SciTech Connect

    Kim, Bohoon; Yoh, Jack J.; Park, Jungsu

    2016-04-14

    A pyrotechnic system consisting of donor/acceptor pair separated by a gap relies on shock attenuation characteristics of the gap material and shock sensitivity of the donor and the acceptor charges. Despite of its common use, a numerical study of such a pyrotechnic train configuration is seldom reported because proper modeling of the full process requires precise capturing of the shock wave attenuation in the gap prior to triggering a full detonation of a high explosive and accurate description of the high strain rate dynamics of the explosively loaded inert confinements. We apply a hybrid particle level-set based multimaterial hydrocode with reactive flow models for pentolite donor and heavily aluminized cyclotrimethylene-trinitramine as the acceptor charge. The complex shock interaction, a critical gap thickness, an acoustic impedance, and go/no-go characteristics of the pyrotechnic system are quantitatively investigated.

  11. Electromagnetic Analysis in Time Domain in Various Configurations for Identification of Hydrocarbon Reservoirs: Numerical Modeling

    NASA Astrophysics Data System (ADS)

    Salazar Rodriguez, J. M.; Vargas Jiménez, C. A.

    2015-12-01

    In this research, various configurations of reservoirs were simulated using finite elements in 3D, in order to analyze the subsoil electromagnetic responses in the time domain. Apparent resistivity curves both early and late time and their respective sensitivities in detecting hydrocarbon reservoirs are found. The maximum sensitivity obtained in the early and late times was 55.72% and 49.32% respectively. The separation of 1km between the transmitter and receiver was used in the simulations, because at shorter distances problems were encountered in in determining the resistivity curves. In addition, it was determined that the current dipole transmitter must be over 800A • m to overcome the level of noise instrumental of the receptor coil.

  12. Computational optimization of the configuration of a spatially resolved spectroscopy sensor for milk analysis.

    PubMed

    Watté, Rodrigo; Aernouts, Ben; Van Beers, Robbe; Postelmans, Annelies; Saeys, Wouter

    2016-04-21

    A global optimizer has been developed, capable of computing the optimal configuration in a probe for spatially resolved reflectance spectroscopy (SRS). The main objective is to minimize the number of detection fibers, while maintaining an accurate estimation of both absorption and scattering profiles. Multiple fibers are necessary to robustify the estimation of optical properties against noise, which is typically present in the measured signals and influences the accuracy of the inverse estimation. The optimizer is based on a robust metamodel-based inverse estimation of the absorption coefficient and a reduced scattering coefficient from the acquired SRS signals. A genetic algorithm is used to evaluate the effect of the fiber placement on the performance of the inverse estimator to find the bulk optical properties of raw milk. The algorithm to find the optimal fiber placement was repeatedly executed for cases with a different number of detection fibers, ranging from 3 to 30. Afterwards, the optimal designs for each considered number of fibers were compared based on their performance in separating the absorption and scattering properties, and the significance of the differences was tested. A sensor configuration with 13 detection fibers was found to be the combination with the lowest number of fibers which provided an estimation performance which was not significantly worse than the one obtained with the best design (30 detection fibers). This design resulted in the root mean squared error of prediction (RMSEP) of 1.411 cm(-1) (R(2) = 0.965) for the estimation of the bulk absorption coefficient values, and 0.382 cm(-1) (R(2) = 0.996) for the reduced scattering coefficient values.

  13. Biomechanical analysis of acromioclavicular joint dislocation repair using coracoclavicular suspension devices in two different configurations.

    PubMed

    Abat, Ferran; Sarasquete, Juan; Natera, Luis Gerardo; Calvo, Ángel; Pérez-España, Manuel; Zurita, Néstor; Ferrer, Jesús; del Real, Juan Carlos; Paz-Jimenez, Eva; Forriol, Francisco

    2015-09-01

    The best treatment option for some acromioclavicular (AC) joint dislocations is controversial. For this reason, the aim of this study was to evaluate the vertical biomechanical behavior of two techniques for the anatomic repair of coracoclavicular (CC) ligaments after an AC injury. Eighteen human cadaveric shoulders in which repair using a coracoclavicular suspension device was initiated after injury to the acromioclavicular joint were included in the study. Three groups were formed; group I (n = 6): control; group II (n = 6): repair with a double tunnel in the clavicle and in the coracoid (with two CC suspension devices); group III (n = 6): repair in a "V" configuration with two tunnels in the clavicle and one in the coracoid (with one CC suspension device). The biomechanical study was performed with a universal testing machine (Electro Puls 3000, Instron, Boulder, MA, USA), with the clamping jaws set in a vertical position. The force required for acromioclavicular reconstruction system failure was analyzed for each cadaveric piece. Group I reached a maximum force to failure of 635.59 N (mean 444.0 N). The corresponding force was 939.37 N (mean 495.6 N) for group II and 533.11 N (mean 343.9 N) for group III. A comparison of the three groups did not find any significant difference despite the loss of resistance presented by group III. Anatomic repair of coracoclavicular ligaments with a double system (double tunnel in the clavicle and in the coracoid) permits vertical translation that is more like that of the acromioclavicular joint. Acromioclavicular repair in a "V" configuration does not seem to be biomechanically sufficient.

  14. Experimental and CFD-PBM Study of Oxygen Mass Transfer Coefficient in Different Impeller Configurations and Operational Conditions of a Two-Phase Partitioning Bioreactor.

    PubMed

    Moradkhani, Hamed; Izadkhah, Mir-Shahabeddin; Anarjan, Navideh

    2017-02-01

    In this work, gas dispersion in a two-phase partitioning bioreactor is analyzed by calculating volumetric oxygen mass transfer coefficient which is modeled using a commercial computational fluid dynamics (CFD), code FLUENT 6.2. Dispersed oxygen bubbles dynamics is based on standard "k-ε" Reynolds-averaged Navier-Stokes (RANS) model. This paper describes a three-dimensional CFD model coupled with population balance equations (PBE) in order to get more confirming results of experimental measurements. Values of k L a are obtained using dynamic gassing-out method. Using the CFD simulation, the volumetric mass transfer coefficient is calculated based on Higbie's penetration theory. Characteristics of mass transfer coefficient are investigated for five configurations of impeller and three different aeration flow rates. The pitched six blade type, due to the creation of downward flow direction, leads to higher dissolved oxygen (DO) concentrations, thereby, higher values of k L a compared with other impeller compositions. The magnitude of dissolved oxygen percentage in the aqueous phase has direct correlation with impeller speed and any increase of the aeration magnitude leads to faster saturation in shorter periods of time. Agitation speeds of 300 to 800 rpm are found to be the most effective rotational speeds for the mass transfer of oxygen in two-phase partitioning bioreactors (TPPB).

  15. Numerical and experimental study of the mesa configuration in high-voltage 4H-SiC PiN rectifiers

    NASA Astrophysics Data System (ADS)

    Deng, Xiao-Chuan; Chen, Xi-Xi; Li, Cheng-Zhan; Shen, Hua-Jun; Zhang, Jin-Ping

    2016-08-01

    The effect of the mesa configuration on the reverse breakdown characteristic of a SiC PiN rectifier for high-voltage applications is analyzed in this study. Three geometrical parameters, i.e., mesa height, mesa angle and mesa bottom corner, are investigated by numerical simulation. The simulation results show that a deep mesa height, a small mesa angle and a smooth mesa bottom (without sub-trench) could contribute to a high breakdown voltage due to a smooth and uniform surface electric field distribution. Moreover, an optimized mesa structure without sub-trench (mesa height of 2.2 μm and mesa angle of 20°) is experimentally demonstrated. A maximum reverse blocking voltage of 4 kV and a forward voltage drop of 3.7 V at 100 A/cm2 are obtained from the fabricated diode with a 30-μm thick N- epi-layer, corresponding to 85% of the ideal parallel-plane value. The blocking characteristic as a function of the JTE dose is also discussed for the PiN rectifiers with and without interface charge. Project supported by the State Key Program of the National Natural Science Foundation of China (Grant No. 61234006), the Open Foundation of the State Key Laboratory of Electronic Thin Films and Integrated Devices, China (Grant No. KFJJ201301), and the National Science and Technology Major Project of the Ministry of Science and Technology, China (Grant No. 2013ZX02305-003).

  16. Analysis of a high speed civil transport configuration at subsonic flow conditions using a Navier-Stokes solver

    NASA Technical Reports Server (NTRS)

    Lessard, Victor R.

    1993-01-01

    Computations of three dimensional vortical flows over a generic High Speed Civil Transport (HSCT) configuration with an aspect ratio of 3.04 are performed using a thin-layer Navier-Stokes solver. The HSCT cruise configuration is modeled without leading or trailing edge flap deflections and without engine nacelles. The flow conditions, which correspond to tests done in the NASA Langley 8-Foot Transonic Pressure Tunnel (TPT), are a subsonic Mach number of 0.3 and Reynolds number of 4.4 million for a range-of-attack (-.23 deg to 17.78 deg). The effects of the farfield boundary location with respect to the body are investigated. The boundary layer is assumed turbulent and simulated using an algebraic turbulence model. The key features of the vortices and their interactions are captured. Grid distribution in the vortex regions is critical for predicting the correct induced lift. Computed forces and surface pressures compare reasonably well with the experimental TPT data.

  17. Design, performance, and analysis of an aquifer thermal-energy-storage experiment using the doublet-well configuration

    SciTech Connect

    Molz, F.J.; Melville, J.G.; Gueven, O.; Parr, A.D.

    1983-09-01

    In March 1980 Auburn University began series of aquifer thermal energy storage (ATES) experiments using the doublet well configuration. The test site was in Mobile, Alabama. The objectives of the three experimental cycles were to demonstrate the technical feasibility of the ATES concept, to identify and resolve operational problems, and to acquire a data base for developing and testing mathematical models. Pre-injection tests were performed and analyses of hydraulic, geochemical, and thermodynamic data were completed. Three injection-storage-recovery cycles had injection volumes of 25,402 m/sup 3/, 58,010 m/sup 3/, and 58,680 m/sup 3/ and average injection temperatures of 58.5/sup 0/C, 81.0/sup 0/C, and 79.0/sup 0/C, respectively. The first cycle injection began in February 1981 and the third cycle recovery was completed in November 1982. Attributable to the doublet well configuration no clogging of injection wells occurred. Energy recovery percentages based on recovery volumes equal to the injection volumes were 56, 45, and 42%. Thermal convection effects were observed. Aquifer nonhomogeneity, not detectable using standard aquifer testing procedures, was shown to reduce recovery efficiency.

  18. Experimental Analysis of Team Performance: Methodological Developments and Research Results.

    DTIC Science & Technology

    1982-07-06

    The effects of a cooperation contingency on behavior in a continuous three-person environment. Journal of the Experimental Analysis of Behavior , 25...J.V. Effects of a pairing contingency on behavior in a three-person programmed environment. Journal of the Experimental Analysis of Behavior , 1978

  19. CHALLENGES IN DATA INTENSIVE ANALYSIS AT SCIENTIFIC EXPERIMENTAL USER FACILITIES

    SciTech Connect

    Kleese van Dam, Kerstin; Li, Dongsheng; Miller, Stephen D.; Cobb, John W.; Green, Mark L.; Ruby, Catherine L.

    2011-12-31

    This chapter will discuss the critical data intensive analysis and visualiza-tion challenges faced by the experimental science community at large scale and laboratory based facilities. The chapter will further highlight initial solutions under development through community efforts and lay out perspectives for the future, such as the potential of more closely linked experimental and computational science approaches, methods to achieve real time analysis capabilities and the challenges and opportunities of data integration across experimental scales, levels of theory and varying techniques.

  20. Low Boom Configuration Analysis with FUN3D Adjoint Simulation Framework

    NASA Technical Reports Server (NTRS)

    Park, Michael A.

    2011-01-01

    Off-body pressure, forces, and moments for the Gulfstream Low Boom Model are computed with a Reynolds Averaged Navier Stokes solver coupled with the Spalart-Allmaras (SA) turbulence model. This is the first application of viscous output-based adaptation to reduce estimated discretization errors in off-body pressure for a wing body configuration. The output adaptation approach is compared to an a priori grid adaptation technique designed to resolve the signature on the centerline by stretching and aligning the grid to the freestream Mach angle. The output-based approach produced good predictions of centerline and off-centerline measurements. Eddy viscosity predicted by the SA turbulence model increased significantly with grid adaptation. Computed lift as a function of drag compares well with wind tunnel measurements for positive lift, but predicted lift, drag, and pitching moment as a function of angle of attack has significant differences from the measured data. The sensitivity of longitudinal forces and moment to grid refinement is much smaller than the differences between the computed and measured data.

  1. Mixed Waste Treatment Cost Analysis for a Range of GeoMelt Vitrification Process Configurations

    SciTech Connect

    Thompson, L. E.

    2002-02-27

    GeoMelt is a batch vitrification process used for contaminated site remediation and waste treatment. GeoMelt can be applied in several different configurations ranging from deep subsurface in situ treatment to aboveground batch plants. The process has been successfully used to treat a wide range of contaminated wastes and debris including: mixed low-level radioactive wastes; mixed transuranic wastes; polychlorinated biphenyls; pesticides; dioxins; and a range of heavy metals. Hypothetical cost estimates for the treatment of mixed low-level radioactive waste were prepared for the GeoMelt subsurface planar and in-container vitrification methods. The subsurface planar method involves in situ treatment and the in-container vitrification method involves treatment in an aboveground batch plant. The projected costs for the subsurface planar method range from $355-$461 per ton. These costs equate to 18-20 cents per pound. The projected cost for the in-container method is $1585 per ton. This cost equates to 80 cents per pound. These treatment costs are ten or more times lower than the treatment costs for alternative mixed waste treatment technologies according to a 1996 study by the US Department of Energy.

  2. Inversion and sensitivity analysis of multi-configuration electromagnetic induction data using Bayesian approach

    NASA Astrophysics Data System (ADS)

    Jadoon, A.; Moghadas, D.; Jadoon, K. Z.; Missimer, T. M.

    2012-12-01

    Electromagnetic induction (EMI) devices are capable of returning a cumulative electrical conductivity that represents a weighted averaged of the electrical conductivity distributed over a certain depth range. Several studies have illustrated fast inversion algorithms to estimate subsurface electrical conductivity. However, there is still a lack of studies that analyze parameter uncertainty, correlation and non-uniqueness for the EMI parameter estimation problem. In this study, a numerical experiment was performed to test a join inversion approach for the Geonics EM34 instrument, by considering different coil offsets (10, 20 and 40 m), different coil orientations (vertical and horizontal), and different frequencies (6.4, 1.6 and 0.4 kHz). To appropriately infer the parameter uncertainty, a Bayesian approach was used in the framework of the DiffeRential Evolution Adaptive Metropolis (DREAM) algorithm. Synthetic examples were analyzed to illustrate how the distribution of acceptable models is affected by the choice of prior information and the coil configuration. The posterior distribution of subsurface conductivities indicate that most of these parameters were well constrained. Field data acquired using the EM34 along a transect for the purpose of hydrogeological characterization were also studied. The proposed approach provides useful information to estimate parameter uncertainty and enables the quantitative mapping of lateral and vertical electrical conductivity variations over large areas.

  3. Validation and Analysis of Numerical Results for a Two-Pass Trapezoidal Channel With Different Cooling Configurations of Trailing Edge.

    PubMed

    Siddique, Waseem; El-Gabry, Lamyaa; Shevchuk, Igor V; Fransson, Torsten H

    2013-01-01

    experimental data. Using the same turbulence model shows that the height of ribs used in the study is not suitable for inducing secondary flow. Also, the orthogonal rib does not strengthen the secondary flow rotational momentum. The comparison between the new designs for trailing edge shows that if pressure drop is acceptable, staggered arrangement is suitable for the outlet pass heat transfer. For the trailing edge wall, the thermal performance for the ribbed trailing edge only was found about 8% better than other configurations.

  4. Histochemical analysis of experimental granulomatous uveitis.

    PubMed

    Kristeva, M; Biswas, J; Pararajasegaram, G; Sevanian, A; Rao, N A

    1991-01-01

    We have previously demonstrated the effects of various inhibitors of arachidonic acid metabolism on experimental lens-induced granulomatous uveitis. In the present study, we investigated the effect of these same inhibitors on the expression of lysosomal enzymes at different stages of choroidal inflammation in experimental lens-induced granulomatous uveitis and compared this to the inflammation observed at each stage examined. Lysosomal enzymes such as acid phosphatase, beta-glucuronidase and succinate dehydrogenase are known to be liberated during the maturation of mononuclear phagocytes to epithelioid cell granulomas. Although animals treated with nordihydroguaiaretic acid showed less severe inflammation than did indomethacin-treated or control animals, none of these agents appeared to affect the expression of acid phosphatase and beta-glucuronidase, as determined histochemically. Succinate dehydrogenase could not be detected in any of the eyes examined, even though sections of liver and kidney from these same animals were positive for this enzyme.

  5. Experimental system and component performance analysis

    SciTech Connect

    Peterman, K.

    1984-10-01

    A prototype dye laser flow loop was constructed to flow test large power amplifiers in Building 169. The flow loop is designed to operate at supply pressures up to 900 psig and flow rates up to 250 GPM. During the initial startup of the flow loop experimental measurements were made to evaluate component and system performance. Three candidate dye flow loop pumps and three different pulsation dampeners were tested.

  6. Two MIS Analysis Methods: An Experimental Comparison.

    ERIC Educational Resources Information Center

    Wang, Shouhong

    1996-01-01

    In China, 24 undergraduate business students applied data flow diagrams (DFD) to a mini-case, and 20 used object-oriented analysis (OOA). DFD seemed easier to learn, but after training, those using the OOA method for systems analysis made fewer errors. (SK)

  7. Two MIS Analysis Methods: An Experimental Comparison.

    ERIC Educational Resources Information Center

    Wang, Shouhong

    1996-01-01

    In China, 24 undergraduate business students applied data flow diagrams (DFD) to a mini-case, and 20 used object-oriented analysis (OOA). DFD seemed easier to learn, but after training, those using the OOA method for systems analysis made fewer errors. (SK)

  8. Analysis of fuel options for the breakeven core configuration of the Advanced Recycling Reactor

    SciTech Connect

    Stauff, N.E.; Klim, T.K.; Taiwo, T.A.; Fiorina, C.; Franceschini, F.

    2013-07-01

    A trade-off study is performed to determine the impacts of various fuel forms on the core design and core physics characteristics of the sodium-cooled Toshiba- Westinghouse Advanced Recycling Reactor (ARR). The fuel forms include oxide, nitride, and metallic forms of U and Th. The ARR core configuration is redesigned with driver and blanket regions in order to achieve breakeven fissile breeding performance with the various fuel types. State-of-the-art core physics tools are used for the analyses. In addition, a quasi-static reactivity balance approach is used for a preliminary comparison of the inherent safety performances of the various fuel options. Thorium-fueled cores exhibit lower breeding ratios and require larger blankets compared to the U-fueled cores, which is detrimental to core compactness and increases reprocessing and manufacturing requirements. The Th cores also exhibit higher reactivity swings through each cycle, which penalizes reactivity control and increases the number of control rods required. On the other hand, using Th leads to drastic reductions in void and coolant expansion coefficients of reactivity, with the potential for enhancing inherent core safety. Among the U-fueled ARR cores, metallic and nitride fuels result in higher breeding ratios due to their higher heavy metal densities. On the other hand, oxide fuels provide a softer spectrum, which increases the Doppler effect and reduces the positive sodium void worth. A lower fuel temperature is obtained with the metallic and nitride fuels due to their higher thermal conductivities and compatibility with sodium bonds. This is especially beneficial from an inherent safety point of view since it facilitates the reactor cool-down during loss of power removal transients. The advantages in terms of inherent safety of nitride and metallic fuels are maintained when using Th fuel. However, there is a lower relative increase in heavy metal density and in breeding ratio going from oxide to metallic

  9. A cost-benefit analysis of alternative device configurations for aviation-checked baggage security screening.

    PubMed

    Jacobson, Sheldon H; Karnani, Tamana; Kobza, John E; Ritchie, Lynsey

    2006-04-01

    The terrorist attacks of September 11, 2001 have resulted in dramatic changes in aviation security. As of early 2003, an estimated 1,100 explosive detection systems (EDS) and 6,000 explosive trace detection machines (ETD) have been deployed to ensure 100% checked baggage screening at all commercial airports throughout the United States. The prohibitive costs associated with deploying and operating such devices is a serious issue for the Transportation Security Administration. This article evaluates the cost effectiveness of the explosive detection technologies currently deployed to screen checked baggage as well as new technologies that could be used in the future. Both single-device and two-device systems are considered. In particular, the expected annual direct cost of using these devices for 100% checked baggage screening under various scenarios is obtained and the tradeoffs between using single- and two-device strategies are studied. The expected number of successful threats under the different checked baggage screening scenarios with 100% checked baggage screening is also obtained. Lastly, a risk-based screening strategy proposed in the literature is analyzed. The results reported suggest that for the existing security setup, with current device costs and probability parameters, single-device systems are less costly and have fewer expected number of successful threats than two-device systems due to the way the second device affects the alarm or clear decision. The risk-based approach is found to have the potential to significantly improve security. The cost model introduced provides an effective tool for the execution of cost-benefit analyses of alternative device configurations for aviation-checked baggage security screening.

  10. Analysis of the Junction Properties of CdS/CdTe Devices in Substrate and Superstrate Configurations

    SciTech Connect

    Dhere, R. G.; Duenow, J. N.; DeHart, C. M.; Li, J. V.; Kuciauskas, D.; Young, M. R.; Alberi, K.; Mascarenhas, A.; Gessert, T. A.

    2011-01-01

    The best efficiency of CdS/CdTe devices fabricated in the substrate configuration reported to date is about 8%, which is about half the 17.3% reported for the conventional superstrate configuration. The performance of substrate devices is affected by lower open-circuit voltage (Voc), about 700 mV, and low fill factor (FF), which indicates that these devices are primarily limited by non-ideal junction properties and possibly by the ohmic contact to CdTe. In our study of the junction properties of superstrate devices, we show that lower-Voc devices (< 720 mV) with SnO2/CdTe and CdS/CdTe structures are true heterojunction devices. High charged defect density at the heterointerfaces is present in the depletion region and contributes to the dark current density, thereby reducing Voc. On the other hand, for higher-performance devices with Voc > 800 mV, the junction is between an n-type, Te-rich CdSTe alloy with a bandgap of 1.45 eV and p-type CdTe with a bandgap of 1.5 eV. Because the crystal structure of both the Te-rich alloy and the CdTe is cubic zinc blende, and the lattice mismatch between the two is minimal, the device in this case can be considered a quasi-homojunction. These higher-Voc devices are therefore affected less by the high charged defect density at the hetero-interface, which lies outside of the depletion region. We present analysis of the junction properties of our recent and improved substrate-configuration devices with Voc well in excess of 800 mV, FF approaching 60%, and efficiencies around 10%. We also compare devices fabricated in both the substrate and superstrate configurations and with comparable Voc in the range of 700 to more than 800 mV. Photoluminescence (PL) and temperature-dependent PL, current density-voltage and quantum efficiency analysis, and modulated reflectance measurements are used to study device properties.

  11. Comparison of NASTRAN analysis with ground vibration results of UH-60A NASA/AEFA test configuration

    NASA Technical Reports Server (NTRS)

    Idosor, Florentino; Seible, Frieder

    1990-01-01

    Preceding program flight tests, a ground vibration test and modal test analysis of a UH-60A Black Hawk helicopter was conducted by Sikorsky Aircraft to complement the UH-60A test plan and NASA/ARMY Modern Technology Rotor Airloads Program. The 'NASA/AEFA' shake test configuration was tested for modal frequencies and shapes and compared with its NASTRAN finite element model counterpart to give correlative results. Based upon previous findings, significant differences in modal data existed and were attributed to assumptions regarding the influence of secondary structure contributions in the preliminary NASTRAN modeling. An analysis of an updated finite element model including several secondary structural additions has confirmed that the inclusion of specific secondary components produces a significant effect on modal frequency and free-response shapes and improves correlations at lower frequencies with shake test data.

  12. Experimentally demonstrate the surface state and optical topological phase transition of one dimensional hyperbolic metamaterials in Otto and KR configuration (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Wei, Chih Chung; Un, Leng-Wai; Yen, Ta-Jen

    2017-05-01

    One-dimension hyperbolic metamaterials (1DHMMs) possess marvelous and considerable applications: hyperlens, spontaneous emission engineering and nonlinear optics. Conventionally, effective medium theory, which is only valid for long wavelength limit, was used to predict and analyze the optical properties and applications. In our previous works, we considered a binary 1DHMM which consists of alternative metallic and dielectric layers, and rigorously demonstrated the existence of surface states and bulk-interface correspondence with the plasmonic band theory from the coupled surface plasmon point of view. In the plasmonic band structure, we can classify 1DHMMs into two classes: metallic-like and dielectric-like, depending on the formation of the surface states with dielectric and metallic material, respectively. Band crossing exists only when the dielectric layers are thicker than the metallic ones, which is independent from the dielectric constants. Furthermore, the 1DHMMs are all metallic-like without band crossing. On the other hand, the 1DHMMs with band crossing are metal-like before the band crossing point, while they are dielectric-like after the band crossing point. In this work, we measure the surface states formed by dielectric material and 1DHMMs with band crossing in Otto configuration. With white light source and fixed incident angle, we measure the reflectance to investigate the existence of the surface states of 1DHMMs with various thickness ratio of metallic to dielectric layers. Conclusively, our results show that the surface states of 1DHMMs exist only when the thickness ratio is larger than 0.15. The disappearance of the surface states indicates the topological phase transition of 1DHMMs. Our experimental results will benefit new applications for manipulating light on the surface of hyperbolic metamaterials.

  13. Evaluation of the influences of various force magnitudes and configurations on scoliotic curve correction using finite element analysis.

    PubMed

    Karimi, Mohammad Taghi; Ebrahimi, Mohammad Hossein; Mohammadi, Ali; McGarry, Anthony

    2017-03-01

    Scoliosis is a lateral curvature in the normally straight vertical line of the spine, and the curvature can be moderate to severe. Different treatment can be used based on severity and age of subjects, but most common treatment for this disease is using orthosis. To design orthosis types of force arrangement can be varied, from transverse loads to vertical loads or combination of them. But it is not well introduced how orthoses control scoliotic curve and how to achieve the maximum correction based on force configurations and magnitude. Therefore, it was aimed to determine the effect of various loads configurations and magnitudes on curve correction of a degenerative scoliotic subject. A scoliotic subject participated in this study. The CT-Scan of the subject was used to produce 3D model of spine. The 3D model of spine was produced by Mimics software and the finite element analysis and deformation of scoliotic curve of the spine under seven different forces and in three different conditions was determined by ABAQUS software. The Cobb angle in scoliosis curve decreased significantly by applying forces. In each condition depends on different forces, different corrections have been achieved. It can be concluded that the configurations of the force application mentioned in this study is effective to decrease the scoliosis curve. Although it is a case study, it can be used for a vast number of subjects to predict the correction of scoliosis curve before orthotic treatment. Moreover, it is recommended that this method and the outputs can be compared with clinical findings.

  14. Cold flow scaleup facility experimental results and comparison of performance at different bed configurations, Volume 1: Topical report, January--December 1983

    SciTech Connect

    Schmidt, D.K.; Yang, W.C.; Ettehadieh, B.; Anestis, T.C.; Haldipur, G.B.; Kettering, E.; O'Rourke, R.E.; Weigle, D.

    1988-12-01

    KRW Energy Systems Inc. is engaged in the continuing development of a pressurized, fluidized-bed gasification process at its Waltz Mill Site in Madison, Pennsylvania. The overall objective of the program is to demonstrate the viability of the KRW process for the environmentally acceptable production of low- and medium-BTU fuel gas from a variety of fossilized carbonaceous feedstocks for electric power generation, synthetic natural gas, chemical feedstocks and industrial fuels. This report presents analysis of the Cold Flow Scaleup Facility (CFSF) operations. Included is work performed on the 3-meter CFSF model using four different bed configurations to check correlations and scale-up criteria developed from studies conducted in small-scale cold flow units and those available in open literature. The 3-meter model permits full front-face viewing of the fluidized bed through a transparent plastic window and with its instrumentation allows detailed studies of jet behavior, bubble dynamics, solid circulation, gas mixing, and related phenomena important to the design of a large-scale gasifier. 87 refs., 95 figs., 56 tabs.

  15. Human Factors Experimental Design and Analysis Reference

    DTIC Science & Technology

    2007-07-01

    reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions...searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection information. Send comments...Robert C. Williges December 2006 Prepared For Collaborative Technology Alliance on Advanced Decision Architectures Micro Analysis

  16. Effects of sprayer configuration on efficacy for the control of scab on crabapple using electron beam analysis.

    PubMed

    Krause, Charles R; Derksen, Richard C; Horst, Leona E; Zhu, Heping; Zondag, Randall

    2009-01-01

    Foliar diseases like apple scab result in significant economic losses to growers each year. Assessment in past studies involved only macroscopic disease ratings. More complete knowledge of the fate and behavior of fungicide has been needed to reduce pesticide use with less off-target contamination. Field studies were conducted in a production nursery for over 4 years. A moderately susceptible cultivar of ornamental crabapple, Malus spp. cv "Candied Apple", was sprayed with a fungicide using two sprayer/nozzle configurations. The fungicide used in this study was Mankocide, combination of Cu(OH)2 and mancozeb that permitted electron beam analysis (EBA) identification based on the presence of Cu, MN and Zn in the molecule and formulation. EBA was conducted using a cold field emission scanning electron microscopy and energy dispersive x-ray microanalyzer. Fresh leaf samples were placed on sticky stubs after each fungicide treatment. The presence or absence of fungal conidia and fungicide residue were measured. EBA permitted direct visualization and identification of the pathogens, morphologically, and chemical characterization of fungicide present. EBA was useful to quantify disease control related to fungicide coverage, sprayer configuration and treatment efficacy.

  17. Four Dimensional Analysis of Free Electron Lasers in the Amplifier Configuration

    DTIC Science & Technology

    2007-12-01

    19 G. TAPERED WIGGLER ...................................20 1. Linear Tapering ..............................21 2...separatrix (black line) and the closed (green line) and open ( red doted line) orbits on a phase space diagram; horizontal axis is the angular...closed orbits until it begins an upward trend, taking the energy away from the optical field. G. TAPERED WIGGLER In this work, an analysis of an FEL

  18. Investigation of advanced counterrotation blade configuration concepts for high speed turboprop systems. Task 5: Unsteady counterrotation ducted propfan analysis. Computer program user's manual

    NASA Technical Reports Server (NTRS)

    Hall, Edward J.; Delaney, Robert A.; Adamczyk, John J.; Miller, Christopher J.; Arnone, Andrea; Swanson, Charles

    1993-01-01

    The primary objective of this study was the development of a time-marching three-dimensional Euler/Navier-Stokes aerodynamic analysis to predict steady and unsteady compressible transonic flows about ducted and unducted propfan propulsion systems employing multiple blade rows. The computer codes resulting from this study are referred to as ADPAC-AOACR (Advanced Ducted Propfan Analysis Codes-Angle of Attack Coupled Row). This report is intended to serve as a computer program user's manual for the ADPAC-AOACR codes developed under Task 5 of NASA Contract NAS3-25270, Unsteady Counterrotating Ducted Propfan Analysis. The ADPAC-AOACR program is based on a flexible multiple blocked grid discretization scheme permitting coupled 2-D/3-D mesh block solutions with application to a wide variety of geometries. For convenience, several standard mesh block structures are described for turbomachinery applications. Aerodynamic calculations are based on a four-stage Runge-Kutta time-marching finite volume solution technique with added numerical dissipation. Steady flow predictions are accelerated by a multigrid procedure. Numerical calculations are compared with experimental data for several test cases to demonstrate the utility of this approach for predicting the aerodynamics of modern turbomachinery configurations employing multiple blade rows.

  19. Aero-acoustic experimental verification of optimum configuration of variable-pitch fans for 40 x 80 foot subsonic wind tunnel

    NASA Technical Reports Server (NTRS)

    Lown, H.

    1977-01-01

    The aerodynamic and acoustic performance of two drive fan configurations (low-speed and high-speed variable pitch design) for a 40 x 80 foot wind tunnel were monitored. A 1/7-scale model was utilized. The necessary aero-acoustic data reduction computer program logic was supplied. Test results were evaluated, and the optimum configuration to be employed in the 40 foot full scale fan was recommended.

  20. Analytical and experimental analysis of magnetorheological elastomers

    NASA Astrophysics Data System (ADS)

    Trabia, Sarah

    Many engineering applications ranging from robotic joints to shock and vibration mitigation can benefit by incorporating components with variable stiffness. In addition, variable stiffness structures can provide haptic feedback (the sense of touch) to the user. In this work, it is proposed to study Magnetorheological Elastomers (MRE), where iron particles within the elastomer compound develop a dipole interaction energy, to be used in a device for haptic feedback. A novel feature of this MRE device is to introduce a field-induced variable shear modulus bias via a permanent magnet and using a current input to the electromagnetic control coil to change the modulus of the elastomer in both directions (softer or harder). In this preliminary work, both computational and experimental results of the proposed MRE design are presented. The design is created in COMSOL to verify that the magnetic field is in the desired direction. MRE was fabricated and characterized using a Bose Dynamic Mechanical Analyzer for the shear modulus. Using this information, it is possible to know how the MRE will react in magnetic fields within the haptic feedback device. Additionally, a model for an MRE is developed in a multi-physics COMSOL program that is linked to a MATLAB function that predicts the shear modulus and incorporates it into the material properties to best simulate the MRE's ability to change shear modulus.

  1. Analysis and composition of a new microwave filter configuration with inhomogeneous dielectric medium

    NASA Astrophysics Data System (ADS)

    Fukasawa, A.

    1982-09-01

    A theoretical study has been undertaken to solve inter-resonator coupling problems, and to design a new structure of microwave bandpass filter. This filter is composed of quarter-wavelength resonators arranged in a housing with the same ends short-circuited. This arrangement of resonators has never been utilized to compose bandpass filters because of the small inter-resonator coupling. The coupling coefficient of TEM resonant lines has been derived theoretically and expressed with capacitive parameters of the coupled lines. The accurate values of capacitances of the lines were obtained by the numerical analysis of the TEM field. By a simple method to make the medium inhomogeneous through removing the dielectric partially, a simplified structure of filter has first been realized based on this theory. Through numerical analysis by the finite difference method, this structure is also shown to have higher unloaded Q of resonator than conventional dielectric-filled coaxial filters to minimize the volume of filters.

  2. Numerical analysis of the performance of rock weirs: Effects of structure configuration on local hydraulics

    USGS Publications Warehouse

    Holmquist-Johnson, C. L.

    2009-01-01

    River spanning rock structures are being constructed for water delivery as well as to enable fish passage at barriers and provide or improve the aquatic habitat for endangered fish species. Current design methods are based upon anecdotal information applicable to a narrow range of channel conditions. The complex flow patterns and performance of rock weirs is not well understood. Without accurate understanding of their hydraulics, designers cannot address the failure mechanisms of these structures. Flow characteristics such as jets, near bed velocities, recirculation, eddies, and plunging flow govern scour pool development. These detailed flow patterns can be replicated using a 3D numerical model. Numerical studies inexpensively simulate a large number of cases resulting in an increased range of applicability in order to develop design tools and predictive capability for analysis and design. The analysis and results of the numerical modeling, laboratory modeling, and field data provide a process-based method for understanding how structure geometry affects flow characteristics, scour development, fish passage, water delivery, and overall structure stability. Results of the numerical modeling allow designers to utilize results of the analysis to determine the appropriate geometry for generating desirable flow parameters. The end product of this research will develop tools and guidelines for more robust structure design or retrofits based upon predictable engineering and hydraulic performance criteria. ?? 2009 ASCE.

  3. Experimental analysis of nature-nurture interactions.

    PubMed

    Wyman, Robert J

    2005-06-01

    The presumed opposition of nature and nurture has been a major concern of western civilization since its beginnings. Christian theologians interpreted Adam and Eve's eating of the forbidden fruit as the origin of an inherited 'original sin'. Saint Augustine explicitly applied the concept to human mental development, arguing that, because of original sin, children are inclined toward evil and education requires physical punishment. For centuries, it was considered parents' moral and religious obligation, not to nurture their children, in our current sense of that word, but to beat the willfulness out of them. 16thC humanists fought back, arguing that "schools have become torture chambers" while it is adults "who corrupt young minds with evil". Locke's (1690) statement that children are born as a 'white paper' was crucial in rejecting the dogma of an inborn (and sinful) nature. The original sin vs. white paper argument merged with another ancient dichotomy: inborn instinct (which controls animal behavior) vs. the reason and free will which humans have. Darwin made the concept of inherited instinct, common to both man and animals, one cornerstone of his theory of evolution. The 20(th)C saw scientists recast the debate as instinct vs. learning, bitterly argued between behaviorists and ethologists. Laboratory experimentation and field observation showed that behavior could develop without learning but also that conditioning paradigms could powerfully mold behavior. The progress of genetics and neurobiology has led to the modern synthesis that neural development, and hence behavior, results from the interdependent action of both heredity and environment. Copyright 2005 Wiley-Liss, Inc.

  4. Numerical and experimental analysis of spallation phenomena

    NASA Astrophysics Data System (ADS)

    Martin, Alexandre; Bailey, Sean C. C.; Panerai, Francesco; Davuluri, Raghava S. C.; Zhang, Huaibao; Vazsonyi, Alexander R.; Lippay, Zachary S.; Mansour, Nagi N.; Inman, Jennifer A.; Bathel, Brett F.; Splinter, Scott C.; Danehy, Paul M.

    2016-12-01

    The spallation phenomenon was studied through numerical analysis using a coupled Lagrangian particle tracking code and a hypersonic aerothermodynamics computational fluid dynamics solver. The results show that carbon emission from spalled particles results in a significant modification of the gas composition of the post-shock layer. Results from a test campaign at the NASA Langley HYMETS facility are presented. Using an automated image processing of short exposure images, two-dimensional velocity vectors of the spalled particles were calculated. In a 30-s test at 100 W/cm2 of cold-wall heat flux, more than 722 particles were detected, with an average velocity of 110 m/s.

  5. Hybrid Experimental-Numerical Stress Analysis.

    DTIC Science & Technology

    1983-04-01

    tension testings of excised strips of the cornea (17] and the sclera E18 ] yielded erroneous modulus of elasticity and Poisson’s ratio by the...Clarke, ASTM 51? 668, 1979, pp. 121 -150. D. Lndet J A.Begley and G. A. Clarke, ASTM STP 668v 1979P pp. 65 - 120. 28. Wilson# W. K., and Oslas, 3. R...Paris, ASTM STP 700, 1900, pp. 174 - 188. 33. Nishioka, T. and Atluri, S. N., "Numerical Analysis of Dynamic Crack Propagation: Generation and

  6. Combined linear theory/impact theory method for analysis and design of high speed configurations

    NASA Technical Reports Server (NTRS)

    Brooke, D.; Vondrasek, D. V.

    1980-01-01

    Pressure distributions on a wing body at Mach 4.63 are calculated. The combined theory is shown to give improved predictions over either linear theory or impact theory alone. The combined theory is also applied in the inverse design mode to calculate optimum camber slopes at Mach 4.63. Comparisons with optimum camber slopes obtained from unmodified linear theory show large differences. Analysis of the results indicate that the combined theory correctly predicts the effect of thickness on the loading distributions at high Mach numbers, and that finite thickness wings optimized at high Mach numbers using unmodified linear theory will not achieve the minimum drag characteristics for which they are designed.

  7. BUMPERII - DESIGN ANALYSIS CODE FOR OPTIMIZING SPACECRAFT SHIELDING AND WALL CONFIGURATION FOR ORBITAL DEBRIS AND METEOROID IMPACTS

    NASA Technical Reports Server (NTRS)

    Hill, S. A.

    1994-01-01

    BUMPERII is a modular program package employing a numerical solution technique to calculate a spacecraft's probability of no penetration (PNP) from man-made orbital debris or meteoroid impacts. The solution equation used to calculate the PNP is based on the Poisson distribution model for similar analysis of smaller craft, but reflects the more rigorous mathematical modeling of spacecraft geometry, orientation, and impact characteristics necessary for treatment of larger structures such as space station components. The technique considers the spacecraft surface in terms of a series of flat plate elements. It divides the threat environment into a number of finite cases, then evaluates each element of each threat. The code allows for impact shielding (shadowing) of one element by another in various configurations over the spacecraft exterior, and also allows for the effects of changing spacecraft flight orientation and attitude. Four main modules comprise the overall BUMPERII package: GEOMETRY, RESPONSE, SHIELD, and CONTOUR. The GEOMETRY module accepts user-generated finite element model (FEM) representations of the spacecraft geometry and creates geometry databases for both meteoroid and debris analysis. The GEOMETRY module expects input to be in either SUPERTAB Universal File Format or PATRAN Neutral File Format. The RESPONSE module creates wall penetration response databases, one for meteoroid analysis and one for debris analysis, for up to 100 unique wall configurations. This module also creates a file containing critical diameter as a function of impact velocity and impact angle for each wall configuration. The SHIELD module calculates the PNP for the modeled structure given exposure time, operating altitude, element ID ranges, and the data from the RESPONSE and GEOMETRY databases. The results appear in a summary file. SHIELD will also determine the effective area of the components and the overall model, and it can produce a data file containing the probability

  8. BUMPERII - DESIGN ANALYSIS CODE FOR OPTIMIZING SPACECRAFT SHIELDING AND WALL CONFIGURATION FOR ORBITAL DEBRIS AND METEOROID IMPACTS

    NASA Technical Reports Server (NTRS)

    Hill, S. A.

    1994-01-01

    BUMPERII is a modular program package employing a numerical solution technique to calculate a spacecraft's probability of no penetration (PNP) from man-made orbital debris or meteoroid impacts. The solution equation used to calculate the PNP is based on the Poisson distribution model for similar analysis of smaller craft, but reflects the more rigorous mathematical modeling of spacecraft geometry, orientation, and impact characteristics necessary for treatment of larger structures such as space station components. The technique considers the spacecraft surface in terms of a series of flat plate elements. It divides the threat environment into a number of finite cases, then evaluates each element of each threat. The code allows for impact shielding (shadowing) of one element by another in various configurations over the spacecraft exterior, and also allows for the effects of changing spacecraft flight orientation and attitude. Four main modules comprise the overall BUMPERII package: GEOMETRY, RESPONSE, SHIELD, and CONTOUR. The GEOMETRY module accepts user-generated finite element model (FEM) representations of the spacecraft geometry and creates geometry databases for both meteoroid and debris analysis. The GEOMETRY module expects input to be in either SUPERTAB Universal File Format or PATRAN Neutral File Format. The RESPONSE module creates wall penetration response databases, one for meteoroid analysis and one for debris analysis, for up to 100 unique wall configurations. This module also creates a file containing critical diameter as a function of impact velocity and impact angle for each wall configuration. The SHIELD module calculates the PNP for the modeled structure given exposure time, operating altitude, element ID ranges, and the data from the RESPONSE and GEOMETRY databases. The results appear in a summary file. SHIELD will also determine the effective area of the components and the overall model, and it can produce a data file containing the probability

  9. Dynamic analysis of Space Shuttle/RMS configuration using continuum approach

    NASA Technical Reports Server (NTRS)

    Ramakrishnan, Jayant; Taylor, Lawrence W., Jr.

    1994-01-01

    The initial assembly of Space Station Freedom involves the Space Shuttle, its Remote Manipulation System (RMS) and the evolving Space Station Freedom. The dynamics of this coupled system involves both the structural and the control system dynamics of each of these components. The modeling and analysis of such an assembly is made even more formidable by kinematic and joint nonlinearities. The current practice of modeling such flexible structures is to use finite element modeling in which the mass and interior dynamics is ignored between thousands of nodes, for each major component. The model characteristics of only tens of modes are kept out of thousands which are calculated. The components are then connected by approximating the boundary conditions and inserting the control system dynamics. In this paper continuum models are used instead of finite element models because of the improved accuracy, reduced number of model parameters, the avoidance of model order reduction, and the ability to represent the structural and control system dynamics in the same system of equations. Dynamic analysis of linear versions of the model is performed and compared with finite element model results. Additionally, the transfer matrix to continuum modeling is presented.

  10. Fault Wear and Friction Evolution: Experimental Analysis

    NASA Astrophysics Data System (ADS)

    Boneh, Y.; Chang, J. C.; Lockner, D. A.; Reches, Z.

    2011-12-01

    Wear is an inevitable product of frictional sliding of brittle rocks as evidenced by the ubiquitous occurrence of fault gouge and slickenside striations. We present here experimental observations designed to demonstrate the relationship between wear and friction and their governing mechanisms. The experiments were conducted with a rotary shear apparatus on solid, ring-shaped rock samples that slipped for displacements up to tens of meters. Stresses, wear and temperature were continuously monitored. We analyzed 86 experiments of Kasota dolomite, Sierra White granite, Pennsylvania quartzite, Karoo gabbro, and Tennessee sandstone at slip velocities ranging from 0.002 to 0.97 m/s, and normal stress from 0.25 to 6.9 MPa. We conducted two types of runs: short slip experiments (slip distance < 25 mm) primarily on fresh, surface-ground samples, designed to analyze initial wear mechanisms; and long slip experiments (slip distance > 3 m) designed to achieve mature wear conditions and to observe the evolution of wear and friction as the fault surfaces evolved. The experiments reveal three wear stages: initial, running-in, and steady-state. The initial stage is characterized by (1) discrete damage striations, the length of which is comparable to total slip , and local pits or plow features; (2) timing and magnitude of fault-normal dilation corresponds to transient changes of normal and shear stresses; and (3) surface roughness increasing with the applied normal stress. We interpret these observations as wear mechanisms of (a) plowing into the fresh rock surfaces; (b) asperity breakage; and (c) asperity climb. The running-in stage is characterized by (1) intense wear-rate over a critical wear distance of Rd = 0.3-2 m; (2) drop of friction coefficient over a weakening distance of Dc = 0.2-4 m; (3) Rd and Dc display positive, quasi-linear relation with each other. We interpret these observations as indicating the organizing of newly-created wear particles into a 'three

  11. Interpolating dynamical systems: Applications to experimental data analysis

    SciTech Connect

    Ecke, R.E.

    1991-01-01

    Experimental data from Rayleigh-Benard convection is used to demonstrate new techniques in data analysis. The data, in the form of Poincare sections, are fit to a map of the plane as a function of a system control parameter. This provides a very useful method for interpolating experimental low-dimensional dynamical systems. The fitted map can then be studied using numerical bifurcation methods or other nonlinear dynamics analysis techniques. 16 refs., 3 figs., 1 tab.

  12. 3-D Experimental Fracture Analysis at High Temperature

    SciTech Connect

    John H. Jackson; Albert S. Kobayashi

    2001-09-14

    T*e, which is an elastic-plastic fracture parameter based on incremental theory of plasticity, was determined numerically and experimentally. The T*e integral of a tunneling crack in 2024-T3 aluminum, three point bend specimen was obtained through a hybrid analysis of moire interferometry and 3-D elastic-plastic finite element analysis. The results were verified by the good agreement between the experimentally and numerically determined T*e on the specimen surface.

  13. Temperature-dependent photoluminescence properties of MnF2: Configurational-coordinate model analysis

    NASA Astrophysics Data System (ADS)

    Arai, Takahiro; Adachi, Sadao

    2011-05-01

    A white MnF2 powder is synthesized by chemical etching of Mn shots in an aqueous HF solution. The optical properties of this synthesized powder are investigated using photoluminescence (PL) analysis, PL excitation spectroscopy, diffuse reflectivity, and PL decay measurements. The MnF2 powder exhibits PL peaks in the red (˜600 nm) and infrared spectral regions (˜780 nm) under visible to ultraviolet excitation. These PL peaks are asymmetric with a tail on the long-wavelength side. Such spectral features and temperature-dependent PL intensities are well interpreted by a newly developed model with Huang-Rhys's factor as the electron-local vibration coupling strength. The ground- and excited-state energy level diagram for the Mn2+ ions in MnF2 is also proposed.

  14. Interactive Analysis of General Beam Configurations using Finite Element Methods and JavaScript

    NASA Astrophysics Data System (ADS)

    Hernandez, Christopher

    Advancements in computer technology have contributed to the widespread practice of modelling and solving engineering problems through the use of specialized software. The wide use of engineering software comes with the disadvantage to the user of costs from the required purchase of software licenses. The creation of accurate, trusted, and freely available applications capable of conducting meaningful analysis of engineering problems is a way to mitigate to the costs associated with every-day engineering computations. Writing applications in the JavaScript programming language allows the applications to run within any computer browser, without the need to install specialized software, since all internet browsers are equipped with virtual machines (VM) that allow the browsers to execute JavaScript code. The objective of this work is the development of an application that performs the analysis of a completely general beam through use of the finite element method. The app is written in JavaScript and embedded in a web page so it can be downloaded and executed by a user with an internet connection. This application allows the user to analyze any uniform or non-uniform beam, with any combination of applied forces, moments, distributed loads, and boundary conditions. Outputs for this application include lists the beam deformations and slopes, as well as lateral and slope deformation graphs, bending stress distributions, and shear and a moment diagrams. To validate the methodology of the GBeam finite element app, its results are verified using the results from obtained from two other established finite element solvers for fifteen separate test cases.

  15. The analysis of experimental data obtained from automotives tests

    NASA Astrophysics Data System (ADS)

    Stoica, R. M.; Radulescu, V. J.; Neagu, D.; Trocan, C.; Copae, I.

    2016-08-01

    The paper highlights the three important and inseparably aspects of the systemic approach of automotives dynamics: taking into account the human-vehicle-field interaction, dealing movement with algorithms specific to system theory and analysis of experimental data with algorithms specific to signals theory.Within the paper, the systemic approach regarding vehicles dynamics is based on experimental data obtained from tests, whereby it is analyzed the movement and there are obtained movement mathematical models through algorithms of systems identification.Likewise, there are shown main analysis methods for experimental data, which uses probability theory, information theory, correlation analysis and variance analysis;in addition, there are highlighted possibilities given by time analysis, frequency analysis and data time-frequency analysis. Identification algorithms and highlighted analysis procedures assure the study of automotives dynamics and fuel saving,by directly using experimental data, or by using mathematical models and applying concepts and algorithms specific to systems theory. Experimental data were obtained by testing automotives with electronic control devices and by using acquisition and storage equipmentsfor data given by the on-board computer and taken from embedded sensors.

  16. Resolution of bone defects of varying dimension and configuration in the marginal portion of the peri-implant bone. An experimental study in the dog.

    PubMed

    Botticelli, Daniele; Berglundh, Tord; Lindhe, Jan

    2004-04-01

    It was demonstrated that a marginal defect of about 1 mm between the bone wall and the metal surface after implant installation can heal with a high degree of bone fill and osseointegration. The aim of the present animal experiment was to study bone healing at implant sites with hard tissue defects of varying dimensions and configuration. Four Labrador dogs were used. All mandibular premolars and first molars were extracted. After 3 months of healing, five experimental sites, two control (C1, C2) and three test (T1, T2, T3) sites, were identified. In all five sites, custom-made implants with a sand-blasted, large-grit, acid-etched (SLA) surface and with an outer dimension of 3.3x10 mm, were used. In site C1, traditional implant installation was performed. In site C2, the marginal 5 mm of the canal, prepared for the implant, was widened to 5.3 mm using a step-drill. Thus, following the installation of the implant, a circumferential gap occurred between the bone tissue and the metal rod that was 5 mm deep and between 1 and 1.25 mm wide. In test site T1, the canal was widened to establish a marginal gap of 2-2.25 mm. In test sites T2 and T3, the marginal 5 mm of the canal was first widened to 5.3 mm (T2) or 7.3 mm (T3). The buccal bone wall opposite the defect was subsequently removed. Following the placement of a cover screw in sites C2, T1, T2, and T3, a resorbable membrane was placed over the defect. All implants were submerged. After 4 months of healing, block biopsies of each implant site were dissected and processed for ground sectioning. The observations disclosed that four-wall defects of different dimensions (1-2.25 mm wide) that occurred in the marginal portion of the recipient sites following implant installation were resolved during healing. Further, at sites where the buccal bone wall during defect preparation was intentionally removed, healing resulted in defect resolution at the mesial, distal, and lingual aspects. At the buccal aspects, healing was

  17. An Operational Configuration of the ARPS Data Analysis System to Initialize WRF in the NM'S Environmental Modeling System

    NASA Technical Reports Server (NTRS)

    Case, Jonathan; Blottman, Pete; Hoeth, Brian; Oram, Timothy

    2006-01-01

    The Weather Research and Forecasting (WRF) model is the next generation community mesoscale model designed to enhance collaboration between the research and operational sectors. The NM'S as a whole has begun a transition toward WRF as the mesoscale model of choice to use as a tool in making local forecasts. Currently, both the National Weather Service in Melbourne, FL (NWS MLB) and the Spaceflight Meteorology Group (SMG) are running the Advanced Regional Prediction System (AIRPS) Data Analysis System (ADAS) every 15 minutes over the Florida peninsula to produce high-resolution diagnostics supporting their daily operations. In addition, the NWS MLB and SMG have used ADAS to provide initial conditions for short-range forecasts from the ARPS numerical weather prediction (NWP) model. Both NM'S MLB and SMG have derived great benefit from the maturity of ADAS, and would like to use ADAS for providing initial conditions to WRF. In order to assist in this WRF transition effort, the Applied Meteorology Unit (AMU) was tasked to configure and implement an operational version of WRF that uses output from ADAS for the model initial conditions. Both agencies asked the AMU to develop a framework that allows the ADAS initial conditions to be incorporated into the WRF Environmental Modeling System (EMS) software. Developed by the NM'S Science Operations Officer (S00) Science and Training Resource Center (STRC), the EMS is a complete, full physics, NWP package that incorporates dynamical cores from both the National Center for Atmospheric Research's Advanced Research WRF (ARW) and the National Centers for Environmental Prediction's Non-Hydrostatic Mesoscale Model (NMM) into a single end-to-end forecasting system. The EMS performs nearly all pre- and postprocessing and can be run automatically to obtain external grid data for WRF boundary conditions, run the model, and convert the data into a format that can be readily viewed within the Advanced Weather Interactive Processing System

  18. Experimental and numerical studies on the issues in laser welding of light-weight alloys in a zero-gap lap joint configuration

    NASA Astrophysics Data System (ADS)

    Harooni, Masoud

    It is advantageous for the transportation industry to use lightweight components in the structure in order to save mass and reduce CO2 emissions. One of the lightest structural metals, magnesium, fulfills the need for mass reduction within the automotive industry. Many of the body structure components in the automotive industry are assembled using joining processes such as fusion welding. Furthermore, laser welding offers a low heat impact, high process rate, joining method which is becoming increasingly popular as the cost for laser systems continues to decrease. However, there is a limited body of work investigating the laser welding of magnesium and therefore, in the current study, different techniques and methods for laser welding of magnesium alloys are numerically and experimentally studied in order to optimize process parameters to achieve high quality welds. A feasibility study was designed in order to study the effect of various laser welding process parameters (such as laser power levels and welding speeds) on weld quality. Three regression models were developed to find the best fit model that relates process parameters to the shear load of the weld. Furthermore, to understand the effect of laser welding parameters on temperature distribution in laser welding of AZ31B magnesium alloy, a numerical model was developed. A rotary Gaussian volumetric body heat source was applied in this study to obtain the temperature history during the laser welding process. Cross-sectional views of the weld beads, temperature history recorded by thermocouples, and temperature history recorded by infrared camera were used to validate the numerical model. In order to study the real-time dynamic behavior of the molten pool and the keyhole during the welding process, a high speed charge-coupled device (CCD) assisted with a green laser as an illumination source was used. In order to observe the presence of pores, prior studies destructively evaluated the weld bead however; in the

  19. Regional scale analysis of landform configuration with base-level (isobase) maps

    NASA Astrophysics Data System (ADS)

    Grohmann, C. H.; Riccomini, C.; Chamani, M. A. C.

    2011-05-01

    Base-level maps (or "isobase maps", as originally defined by Filosofov, 1960), express a relationship between valley order and topography. The base-level map can be seen as a "simplified" version of the original topographic surface, from which the "noise" of the low-order stream erosion was removed. This method is able to identify areas with possible tectonic influence even within lithologically uniform domains. Base-level maps have been recently applied in semi-detail scale (e.g., 1:50 000 or larger) morphotectonic analysis. In this paper, we present an evaluation of the method's applicability in regional-scale analysis (e.g., 1:250 000 or smaller). A test area was selected in northern Brazil, at the lower course of the Araguaia and Tocantins rivers. The drainage network extracted from SRTM30_PLUS DEMs with spatial resolution of approximately 900 m was visually compared with available topographic maps and considered to be compatible with a 1:1,000 000 scale. Regarding the interpretation of regional-scale morphostructures, the map constructed with 2nd and 3rd-order valleys was considered to present the best results. Some of the interpreted base-level anomalies correspond to important shear zones and geological contacts present in the 1:5 000 000 Geological Map of South America. Others have no correspondence with mapped Precambrian structures and are considered to represent younger, probably neotectonic, features. A strong E-W orientation of the base-level lines over the inflexion of the Araguaia and Tocantins rivers, suggest a major drainage capture. A N-S topographic swath profile over the Tocantins and Araguaia rivers reveals a topographic pattern which, allied with seismic data showing a roughly N-S direction of extension in the area, lead us to interpret this lineament as an E-W, southward-dipping normal fault. There is also a good visual correspondence between the base-level lineaments and geophysical anomalies. A NW-SE lineament in the southeast of the study

  20. Comparative analysis of various CO2 configurations in supermarket refrigeration systems

    SciTech Connect

    Sharma, Vishaldeep; Fricke, Brian; Bansal, Pradeep

    2014-07-09

    Our paper presents an analysis of various CO2 transcritical and cascade/secondary loop refrigeration systems that are becoming popular in supermarket applications with the objective of optimizing the operating parameters of these systems. In addition, the performance of selected CO2-based refrigeration systems is compared to the baseline R404A multiplex direct expansion system using bin analyses in the eight climate zones of the United States. Moreover, for the refrigeration systems investigated, it was found that the Transcritical Booster System with Bypass Compressor (TBS-BC) had the lowest energy consumption for ambient temperatures (Tamb) less than 8 °C, and for higher ambient temperatures the R404A direct expansion system was found to have the lowest energy consumption. Finally, the TBS-BC performs equivalent to or better than the R404A direct expansion system in the northern two-thirds of the US. For the southern portion of the US, the R404A multiplex DX system performs better than CO2 systems.

  1. Comparative analysis of various CO2 configurations in supermarket refrigeration systems

    DOE PAGES

    Sharma, Vishaldeep; Fricke, Brian; Bansal, Pradeep

    2014-07-09

    Our paper presents an analysis of various CO2 transcritical and cascade/secondary loop refrigeration systems that are becoming popular in supermarket applications with the objective of optimizing the operating parameters of these systems. In addition, the performance of selected CO2-based refrigeration systems is compared to the baseline R404A multiplex direct expansion system using bin analyses in the eight climate zones of the United States. Moreover, for the refrigeration systems investigated, it was found that the Transcritical Booster System with Bypass Compressor (TBS-BC) had the lowest energy consumption for ambient temperatures (Tamb) less than 8 °C, and for higher ambient temperatures themore » R404A direct expansion system was found to have the lowest energy consumption. Finally, the TBS-BC performs equivalent to or better than the R404A direct expansion system in the northern two-thirds of the US. For the southern portion of the US, the R404A multiplex DX system performs better than CO2 systems.« less

  2. Nonlinear visco-elastic finite element analysis of different porcelain veneers configuration.

    PubMed

    Sorrentino, Roberto; Apicella, Davide; Riccio, Carlo; Gherlone, Enrico; Zarone, Fernando; Aversa, Raffaella; Garcia-Godoy, Franklin; Ferrari, Marco; Apicella, Antonio

    2009-11-01

    This study is aimed at evaluating the biomechanical behavior of feldspathic versus alumina porcelain veneers. A 3D numerical model of a maxillary central incisor, with the periodontal ligament (PDL) and the alveolar bone was generated. Such model was made up of four main volumes: dentin, enamel, cement layer and veneer. Incisors restored with alumina and feldspathic porcelain veneers were compared with a natural sound tooth (control). Enamel, cementum, cancellous and cortical bone were considered as isotropic elastic materials; on the contrary, the tubular structure of dentin was designed as elastic orthotropic. The nonlinear visco-elatic behavior of the PDL was considered. The veneer volumes were coupled with alumina and feldspathic porcelain mechanical properties. The adhesive layers were modeled in the FE environment using spring elements. A 50N load applied at 60 degrees angle with tooth longitudinal axis was applied and validated. Compressive stresses were concentrated on the external surface of the buccal side of the veneer close to the incisal margin; such phenomenon was more evident in the presence of alumina. Tensile stresses were negligible when compared to compressive ones. Alumina and feldspathic ceramic were characterized by a different biomechanical behavior in terms of elastic deformations and stress distributions. The ultimate strength of both materials was not overcome in the performed analysis.

  3. Differential Drag Analysis to Infer the Geometrical Configuration of a Cubesat

    NASA Astrophysics Data System (ADS)

    Bussy-Virat, C.; Ridley, A. J.; Cutler, J.; Sharma, S.; Judd, E.

    2016-12-01

    On May 16th, 2016, the Miniature X-ray Solar Spectrometer (MinXSS) and the CubeSat investigating Atmospheric Density Response to Extreme driving (CADRE) were deployed from the International Space Station. While communication with MinXSS was quickly established, it has been impossible to interact with CADRE thus far. A likely reason could be that its solar panels did not open, preventing the antenna from fully functioning and eliminating communication with the ground stations. An orbit propagator that was developed for mission design and analysis was used to model the trajectories of the satellites. By comparing the drag accelerations on the two CubeSats, we are attempting to infer the number of solar panels that CADRE deployed. Ensemble simulations allow the modeling of uncertainties on its attitude, as it is likely to tumble if no solar panel was deployed. This technique introduces many challenges, as there are many unknowns, including the drag coefficient, the attitude, and the thermospheric density. We present results of this study, as well as these challenges that were encountered.

  4. Theoretical and experimental analysis of liquid layer instability in hybrid rocket engines

    NASA Astrophysics Data System (ADS)

    Kobald, Mario; Verri, Isabella; Schlechtriem, Stefan

    2015-03-01

    The combustion behavior of different hybrid rocket fuels has been analyzed in the frame of this research. Tests have been performed in a 2D slab burner configuration with windows on two sides. Four different liquefying paraffin-based fuels, hydroxyl terminated polybutadiene (HTPB) and high-density polyethylene (HDPE) have been tested in combination with gaseous oxygen (GOX). Experimental high-speed video data have been analyzed manually and with the proper orthogonal decomposition (POD) technique. Application of POD enables the recognition of the main structures of the flow field and the combustion flame appearing in the video data. These results include spatial and temporal analysis of the structures. For liquefying fuels these spatial values relate to the wavelengths associated to the Kelvin Helmholtz Instability (KHI). A theoretical long-wave solution of the KHI problem shows good agreement with the experimental results. Distinct frequencies found in the POD analysis can be related to the precombustion chamber configuration which can lead to vortex shedding phenomena.

  5. Laryngoscopic and spectral analysis of laryngeal and pharyngeal configuration in non-classical singing styles.

    PubMed

    Guzman, Marco; Lanas, Andres; Olavarria, Christian; Azocar, Maria Josefina; Muñoz, Daniel; Madrid, Sofia; Monsalve, Sebastian; Martinez, Francisca; Vargas, Sindy; Cortez, Pedro; Mayerhoff, Ross M

    2015-01-01

    The present study aimed to assess three different singing styles (pop, rock, and jazz) with laryngoscopic, acoustic, and perceptual analysis in healthy singers at different loudness levels. Special emphasis was given to the degree of anterior-posterior (A-P) laryngeal compression, medial laryngeal compression, vertical laryngeal position (VLP), and pharyngeal compression. Prospective study. Twelve female trained singers with at least 5 years of voice training and absence of any voice pathology were included. Flexible and rigid laryngeal endoscopic examinations were performed. Voice recording was also carried out. Four blinded judges were asked to assess laryngoscopic and auditory perceptual variables using a visual analog scale. All laryngoscopic parameters showed significant differences for all singing styles. Rock showed the greatest degree for all of them. Overall A-P laryngeal compression scores demonstrated significantly higher values than overall medial compression and VLP. High loudness level produced the highest degree of A-P compression, medial compression, pharyngeal compression, and the lowest VLP for all singing styles. Additionally, rock demonstrated the highest values for alpha ratio (less steep spectral slope), L1-L0 ratio (more glottal adduction), and Leq (more vocal intensity). Statistically significant differences between the three loudness levels were also found for these acoustic parameters. Rock singing seems to be the style with the highest degree of both laryngeal and pharyngeal activity in healthy singers. Although, supraglottic activity during singing could be labeled as hyperfunctional vocal behavior, it may not necessarily be harmful, but a strategy to avoid vocal fold damage. Copyright © 2015 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  6. TAL Performance and Mission Analysis in a CDL Capacitor Powered Direct-Drive Configuration

    NASA Technical Reports Server (NTRS)

    Hrbud, Ivana; Rose, M. Frank; Oleson, Steve R.; Jenkins, Rhonald M.

    1999-01-01

    The goals of this research are (1) to prove the concept feasibility of a direct-drive electric propulsion system, and (2) to evaluate the performance and characteristics of a Russian TAL (Thruster with Anode Layer) operating in a long-pulse mode, powered by a capacitor-based power source developed at Space Power Institute. The TAL, designated D-55, is characterized by an external acceleration zone and is powered by a unique chemical double layer (CDL) capacitor bank with a capacitance of 4 F at a charge voltage of 400 V. Performance testing of this power supply on the TAL was conducted at NASA Lewis Research Center in Cleveland, OH. Direct thrust measurements of the TAL were obtained at CDL power levels ranging from 450 to 1750 W. The specific impulse encompassed a range from 1150 s to 2200 s, yielding thruster system efficiencies between 50 and 60%. Preliminary mission analysis of the CDL direct-drive concept and other electric propulsion options was performed for the ORACLE spacecraft in 6am/6pm and 12am/12pm, 300 km sun-synchronous orbits. The direct-drive option was competitive with the other systems by increasing available net mass between 5 and 42% and reducing two-year system wet mass between 18 and 63%. Overall, the electric propulsion power requirements for the satellite solar array were reduced between 57 and 91% depending oil the orbit evaluated The direct-drive, CDL capacitor-based concept in electric propulsion thus promises to be a highly-efficient, viable alternative for satellite operations in specific near-Earth missions.

  7. Mathematical analysis of frontal affinity chromatography in particle and membrane configurations.

    PubMed

    Tejeda-Mansir, A; Montesinos, R M; Guzmán, R

    2001-10-30

    The scaleup and optimization of large-scale affinity-chromatographic operations in the recovery, separation and purification of biochemical components is of major industrial importance. The development of mathematical models to describe affinity-chromatographic processes, and the use of these models in computer programs to predict column performance is an engineering approach that can help to attain these bioprocess engineering tasks successfully. Most affinity-chromatographic separations are operated in the frontal mode, using fixed-bed columns. Purely diffusive and perfusion particles and membrane-based affinity chromatography are among the main commercially available technologies for these separations. For a particular application, a basic understanding of the main similarities and differences between particle and membrane frontal affinity chromatography and how these characteristics are reflected in the transport models is of fundamental relevance. This review presents the basic theoretical considerations used in the development of particle and membrane affinity chromatography models that can be applied in the design and operation of large-scale affinity separations in fixed-bed columns. A transport model for column affinity chromatography that considers column dispersion, particle internal convection, external film resistance, finite kinetic rate, plus macropore and micropore resistances is analyzed as a framework for exploring further the mathematical analysis. Such models provide a general realistic description of almost all practical systems. Specific mathematical models that take into account geometric considerations and transport effects have been developed for both particle and membrane affinity chromatography systems. Some of the most common simplified models, based on linear driving-force (LDF) and equilibrium assumptions, are emphasized. Analytical solutions of the corresponding simplified dimensionless affinity models are presented. Particular

  8. Unsteady aerodynamic flow field analysis of the space shuttle configuration. Part 3: Unsteady aerodynamics of bodies with concave nose geometries

    NASA Technical Reports Server (NTRS)

    Ericsson, L. E.; Reding, J. P.

    1976-01-01

    An analysis of the unsteady aerodynamics of bodies with concave nose geometries was performed. The results show that the experimentally observed pulsating flow on spiked bodies and in forward facing cavities can be described by the developed simple mathematical model of the phenomenon. Static experimental data is used as a basis for determination of the oscillatory frequency of spike-induced flow pulsations. The agreement between predicted and measured reduced frequencies is generally very good. The spiked-body mathematical model is extended to describe the pulsations observed in forward facing cavities and it is shown that not only the frequency but also the pressure time history can be described with the accuracy needed to predict the experimentally observed time average effects. This implies that it should be possible to determine analytically the impact of the flow pulsation on the structural integrity of the nozzles for the jettisoned empty SRM-shells.

  9. One to one imagery using single hololens configuration

    NASA Astrophysics Data System (ADS)

    Ghosh, Abhijit; Nirala, A. K.

    2014-11-01

    The present study proposes a novel technique for one to one imagery using a single hololens imaging configuration for the first time to the best of our information. Detailed theoretical analysis and experimental realization of a single hololens imaging configuration has been presented. In order to substantiate the one to one imaging capacity of the system, experiments have been performed in both transmissions as well as reflection mode.

  10. Tandem configurations of variably duplicated segments of 22q11.2 confirmed by fiber-FISH analysis.

    PubMed

    Shimojima, Keiko; Okamoto, Nobuhiko; Inazu, Tetsuya; Yamamoto, Toshiyuki

    2011-11-01

    22q11.2 duplication syndrome has recently been established as a new syndrome manifesting broad clinical phenotypes including mental retardation. It is reciprocal to DiGeorge (DGS)/velo-cardio-facial syndrome (VCFS), in which the same portion of the chromosome is hemizygously deleted. Deletions and duplications of the 22q11.2 region are facilitated by the low-copy repeats (LCRs) flanking this region. In this study, we aimed to identify the directions of the duplicated segments of 22q11.2 to better understand the mechanism of chromosomal duplication. To achieve this aim, we accumulated samples from four patients with 22q11.2 duplications. One of the patients had an atypically small (741 kb) duplication of 22q11.2. The centromeric end of the breakpoint was on LCR22A, but the telomeric end was between LCR22A and B. Therefore, the duplicated segment did not include T-box 1 gene (TBX1), the gene primarily responsible for the DGS/VCFS. As this duplication was shared by the patient's healthy mother, this appears to be a benign copy-number variation rather than a disease-causing alteration. The other three patients showed 3.0 or 4.0 Mb duplications flanked by LCRs. The directions of the duplicated segments were investigated by fiber-fluorescence in situ hybridization analysis. All samples showed tandem configurations. These results support the hypothesized mechanism of non-allelic homologous recombination with flanking LCRs and add additional evidence that many interstitial duplications are aligned as tandem configurations.

  11. Stress distribution on scalloped implants with different microthread and connection configurations using three-dimensional finite element analysis.

    PubMed

    Choi, Kyung-soo; Park, Seong-hun; Lee, Jae-hoon; Jeon, Young-chan; Yun, Mi-Jung; Jeong, Chang-mo

    2012-01-01

    The objective of this study was to investigate the effects of different microthread designs and implant-abutment connection configurations of scalloped implants on stress distribution in bone using three-dimensional finite element analysis. Three different designs of scalloped implants (two different microthread designs and one without microthreads) with two different connection systems and two flat-top implants with similar connection systems were compared in a bone model that mimicked the anterior maxilla. Vertical and oblique (30-degree) loading with 100 N of force was applied to eight models. Peak stress levels and the distribution of stress were observed. The stress pattern of scalloped implants was distinctively different from that observed on flat-top implants. Scalloped implants showed peak stresses in the proximal cortical bone as well as in the buccal and palatal cortical bone, whereas flat-top implants showed peak stresses mainly in the buccal and palatal cortical bone and limited stress in the proximal bone. The scalloped implant without microthreads and a conical platform-switched connection demonstrated the lowest peak stress levels. The scalloped implant with a straight platform connection generally showed peak stress that was two to three times higher than that seen in the conical platform-switched model. Peak stress levels in scalloped implants varied with microthread designs, connection configurations, and the direction of loading. The conical platform-switched connection seemed more important for a scalloped implant than the microthread design in reducing loading stresses exerted on the surrounding bone. Scalloped implants without microthread and a with a conical platform-switched connection or closed microthreads and a conical platform-switched connection showed consistently lower buccal bone stress than the flat-top implants in areas where the bone had a sloping and scalloping shape.

  12. Experimental analysis of green roof substrate detention characteristics.

    PubMed

    Yio, Marcus H N; Stovin, Virginia; Werdin, Jörg; Vesuviano, Gianni

    2013-01-01

    Green roofs may make an important contribution to urban stormwater management. Rainfall-runoff models are required to evaluate green roof responses to specific rainfall inputs. The roof's hydrological response is a function of its configuration, with the substrate - or growing media - providing both retention and detention of rainfall. The objective of the research described here is to quantify the detention effects due to green roof substrates, and to propose a suitable hydrological modelling approach. Laboratory results from experimental detention tests on green roof substrates are presented. It is shown that detention increases with substrate depth and as a result of increasing substrate organic content. Model structures based on reservoir routing are evaluated, and it is found that a one-parameter reservoir routing model coupled with a parameter that describes the delay to start of runoff best fits the observed data. Preliminary findings support the hypothesis that the reservoir routing parameter values can be defined from the substrate's physical characteristics.

  13. An integrated platform for directly widely-targeted quantitative analysis of feces part I: Platform configuration and method validation.

    PubMed

    Song, Yuelin; Song, Qingqing; Li, Jun; Zheng, Jiao; Li, Chun; Zhang, Yuan; Zhang, Lingling; Jiang, Yong; Tu, Pengfei

    2016-07-08

    Direct analysis is of great importance to understand the real chemical profile of a given sample, notably biological materials, because either chemical degradation or diverse errors and uncertainties might be resulted from sophisticated protocols. In comparison with biofluids, it is still challenging for direct analysis of solid biological samples using high performance liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Herein, a new analytical platform was configured by online hyphenating pressurized liquid extraction (PLE), turbulent flow chromatography (TFC), and LC-MS/MS. A facile, but robust PLE module was constructed based on the phenomenon that noticeable back-pressure can be generated during rapid fluid passing through a narrow tube. TFC column that is advantageous at extracting low molecular analytes from rushing fluid was employed to link at the outlet of the PLE module to capture constituents-of-interest. An electronic 6-port/2-position valve was introduced between TFC column and LC-MS/MS to fragment each measurement into extraction and elution phases, whereas LC-MS/MS took the charge of analyte separation and monitoring. As a proof of concept, simultaneous determination of 24 endogenous substances including eighteen steroids, five eicosanoids, and one porphyrin in feces was carried out in this paper. Method validation assays demonstrated the analytical platform to be qualified for directly simultaneous measurement of diverse endogenous analytes in fecal matrices. Application of this integrated platform on homolog-focused profiling of feces is discussed in a companion paper.

  14. Morphofunctional analysis of experimental model of esophageal achalasia in rats.

    PubMed

    Sabirov, A G; Raginov, I S; Burmistrov, M V; Chelyshev, Y A; Khasanov, R Sh; Moroshek, A A; Grigoriev, P N; Zefirov, A L; Mukhamedyarov, M A

    2010-10-01

    We carried out a detailed analysis of rat model of esophageal achalasia previously developed by us. Manifest morphological and functional disorders were observed in experimental achalasia: hyperplasia of the squamous epithelium, reduced number of nerve fibers, excessive growth of fibrous connective tissue in the esophageal wall, high contractile activity of the lower esophageal sphincter, and reduced motility of the longitudinal muscle layer. Changes in rat esophagus observed in experimental achalasia largely correlate with those in esophageal achalasia in humans. Hence, our experimental model can be used for the development of new methods of disease treatment.

  15. Experimental performance and parametric analysis of heat pipe heat exchanger for air conditioning application integrated with evaporative cooling

    NASA Astrophysics Data System (ADS)

    Jadhav, Tushar S.; Lele, Mandar M.

    2017-04-01

    The experimental performance of different heat pipe heat exchanger (HPHX) configurations using distilled water as the working fluid is reported in the present study. The three HPHX configurations in the present investigation include HPHX with single wick structure (HPHX 1), HPHX with composite wick structure (HPHX 2) and hybrid HPHX (HPHX 3) which is the combination of HPHX 1 and HPHX 2. The parameters considered for the parametric analysis of HPHX in all the three configurations are outdoor air dry bulb temperature entering the evaporator section of HPHX (OADBT), return air dry bulb temperature entering the condenser section of HPHX (RADBT), outdoor air velocity (Ve) and return air velocity (Vc). The OADBT is varied between 40 and 24 °C and the outdoor & return air velocities between 0.6 and 2.4 m/s. The parametric analysis of HPHX without evaporative cooling is studied for RADBT = 24 °C whereas RADBT is maintained at 20 °C for the parametric analysis of HPHX integrated with evaporative cooling. In comparison with HPHX without evaporative cooling, the performance of HPHX with evaporative cooling is enhanced by 17% for single wick structure (HPHX 1), 47% for composite wick structure (HPHX 2) and 59% for hybrid HPHX (HPHX 3) for OADBT = 40 °C and at Ve = Vc of 0.6 m/s. The results of the experimental analysis highlights the benefits of HPHX integrated with evaporative cooling for achieving significant energy savings in air conditioning application.

  16. Absolute configuration determination through the unique intramolecular excitonic coupling in the circular dichroisms of o,p'-DDT and o,p'-DDD. A combined experimental and theoretical study.

    PubMed

    Tanaka, Hiroki; Inoue, Yoshihisa; Nakano, Takeshi; Mori, Tadashi

    2017-04-12

    Circular dichroisms (CDs) of the o,p'-isomers of 1,1,1-trichloro- and 1,1-dichloro-2,2-bis(chlorophenyl)ethanes (DDT and DDD) were investigated experimentally and theoretically. A series of strong Cotton effect peaks in a characteristic negative-negative-positive-negative, or its mirror-imaged, pattern were observed in the CD spectra of these persistent organic pollutants. The theoretical CD spectra at the SAC-CI/B95(d) and RI-CC2/def2-TZVPP levels well reproduced the experimental ones, enabling us to unambiguously assign the absolute configuration of (+)-DDT and (-)-DDD as S.

  17. Statistical inference in behavior analysis: Experimental control is better

    PubMed Central

    Perone, Michael

    1999-01-01

    Statistical inference promises automatic, objective, reliable assessments of data, independent of the skills or biases of the investigator, whereas the single-subject methods favored by behavior analysts often are said to rely too much on the investigator's subjective impressions, particularly in the visual analysis of data. In fact, conventional statistical methods are difficult to apply correctly, even by experts, and the underlying logic of null-hypothesis testing has drawn criticism since its inception. By comparison, single-subject methods foster direct, continuous interaction between investigator and subject and development of strong forms of experimental control that obviate the need for statistical inference. Treatment effects are demonstrated in experimental designs that incorporate replication within and between subjects, and the visual analysis of data is adequate when integrated into such designs. Thus, single-subject methods are ideal for shaping—and maintaining—the kind of experimental practices that will ensure the continued success of behavior analysis. PMID:22478328

  18. Investigation of advanced counterrotation blade configuration concepts for high speed turboprop systems. Task 4: Advanced fan section aerodynamic analysis

    NASA Technical Reports Server (NTRS)

    Crook, Andrew J.; Delaney, Robert A.

    1992-01-01

    The purpose of this study is the development of a three-dimensional Euler/Navier-Stokes flow analysis for fan section/engine geometries containing multiple blade rows and multiple spanwise flow splitters. An existing procedure developed by Dr. J. J. Adamczyk and associates and the NASA Lewis Research Center was modified to accept multiple spanwise splitter geometries and simulate engine core conditions. The procedure was also modified to allow coarse parallelization of the solution algorithm. This document is a final report outlining the development and techniques used in the procedure. The numerical solution is based upon a finite volume technique with a four stage Runge-Kutta time marching procedure. Numerical dissipation is used to gain solution stability but is reduced in viscous dominated flow regions. Local time stepping and implicit residual smoothing are used to increase the rate of convergence. Multiple blade row solutions are based upon the average-passage system of equations. The numerical solutions are performed on an H-type grid system, with meshes being generated by the system (TIGG3D) developed earlier under this contract. The grid generation scheme meets the average-passage requirement of maintaining a common axisymmetric mesh for each blade row grid. The analysis was run on several geometry configurations ranging from one to five blade rows and from one to four radial flow splitters. Pure internal flow solutions were obtained as well as solutions with flow about the cowl/nacelle and various engine core flow conditions. The efficiency of the solution procedure was shown to be the same as the original analysis.

  19. SSME/side loads analysis for flight configuration, revision A. [structural analysis of space shuttle main engine under side load excitation

    NASA Technical Reports Server (NTRS)

    Holland, W.

    1974-01-01

    This document describes the dynamic loads analysis accomplished for the Space Shuttle Main Engine (SSME) considering the side load excitation associated with transient flow separation on the engine bell during ground ignition. The results contained herein pertain only to the flight configuration. A Monte Carlo procedure was employed to select the input variables describing the side load excitation and the loads were statistically combined. This revision includes an active thrust vector control system representation and updated orbiter thrust structure stiffness characteristics. No future revisions are planned but may be necessary as system definition and input parameters change.

  20. Experimental Identification of Spin-Parities and Single-Particle Configurations in {sup 257}No and Its {alpha}-Decay Daughter {sup 253}Fm

    SciTech Connect

    Asai, M.; Tsukada, K.; Ichikawa, S.; Nagame, Y.; Nishinaka, I.; Akiyama, K.; Sakama, M.; Ishii, T.; Osa, A.; Oura, Y.; Sueki, K.; Shibata, M.

    2005-09-02

    {alpha}-{gamma} and {alpha}-electron coincidence spectroscopy for a short-lived heavy actinide nucleus {sup 257}No (T{sub 1/2}=24.5 s) has been performed using a gas-jet transport system and an on-line isotope separator. Spin-parities of excited states in {sup 253}Fm fed by the {alpha} decay of {sup 257}No have been identified on the basis of the measured internal conversion coefficients. The {nu}3/2{sup +}[622] configuration has been assigned to the ground state of {sup 257}No as well as to the 124.1 keV level in {sup 253}Fm. It was found that the ground-state configuration of {sup 257}No is different from that of lighter N=155 isotones.

  1. Versatile composite amplifier configuration

    NASA Astrophysics Data System (ADS)

    Gift, Stephan J. G.; Maundy, Brent

    2015-06-01

    This paper describes a versatile composite amplifier in which a current feedback amplifier (CFA) drives an operational amplifier (OPA). In the conventional OPA-CFA composite amplifier, an OPA drives a CFA resulting in a composite structure that combines the DC input stability of the OPA and the high speed capability of the CFA. The proposed composite configuration combines different features of the CFA and OPA, specifically the constant bandwidth property of the CFA and the high power and high current output capacity of the OPA. The new circuit is easily implemented in the standard inverting and non-inverting configurations using commercially available devices, and the accuracy and constant bandwidth features were experimentally verified. Local feedback around the associated CFA ensures that the proposed composite amplifier possesses a higher level of bandwidth constancy than a single CFA.

  2. Thermo-mechanical analysis of an internal cooling system with various configurations of a combustion liner after shell

    NASA Astrophysics Data System (ADS)

    Moon, Hokyu; Kim, Kyung Min; Park, Jun Su; Kim, Beom Seok; Cho, Hyung Hee

    2015-12-01

    The after-shell section, which is part of the gas turbine combustion liner, is exposed to the hottest combustion gas. Various cooling schemes have been applied to protect against severe thermal load. However, there is a significant discrepancy in the thermal expansion with large temperature differences, resulting in thermo-mechanical crack formation. In this study, to reduce combustion liner damage, thermo-mechanical analysis was conducted on three after-shell section configurations: inline-discrete divider wall, staggered divider wall, and swirler wall arrays. These array components are well-known heat-transfer enhancement structures in the duct. In the numerical analyses, the heat transfer characteristics, temperature and thermo-mechanical stress distribution were evaluated using finite volume method and finite element method commercial codes. As a result, we demonstrated that the temperature and the thermo-mechanical stress distribution were readily dependent on the structural array for cooling effectiveness and structural support in each modified cooling system. Compared with the reference model, the swirler wall array was most effective in diminishing the thermo-mechanical stress concentration, especially on the inner ring that is vulnerable to crack formation.

  3. Performance analysis of different ORC configurations for thermal energy and LNG cold energy hybrid power generation system

    NASA Astrophysics Data System (ADS)

    Sun, Zhixin; Wang, Feng; Wang, Shujia; Xu, Fuquan; Lin, Kui

    2017-01-01

    This paper presents a thermal energy and Liquefied natural gas (LNG) cold energy hybrid power generation system. Performances of four different Organic Rankine cycle (ORC) configurations (the basic, the regenerative, the reheat and the regenerative-reheat ORCs) are studied based on the first and the second law of thermodynamics. Dry organic fluid R245fa is selected as the typical working fluid. Parameter analysis is also conducted in this paper. The results show that regeneration could not increase the thermal efficiency of the thermal and cold energy hybrid power generation system. ORC with the reheat process could produce more specific net power output but it may also reduce the system thermal efficiency. The basic and the regenerative ORCs produce higher thermal efficiency while the regenerative-reheat ORC performs best in the exergy efficiency. A preheater is necessary for the thermal and cold energy hybrid power generation system. And due to the presence of the preheater, there will be a step change of the system performance as the turbine inlet pressure rises.

  4. Deciding to tell: Qualitative configurational analysis of decisions to disclose experience of intimate partner violence in antenatal care.

    PubMed

    Spangaro, Jo; Koziol-McLain, Jane; Zwi, Anthony; Rutherford, Alison; Frail, Mary-Anne; Ruane, Jennifer

    2016-04-01

    Intimate partner violence (IPV) is a significant global public health risk causing premature death and morbidity that largely remains hidden. Understanding decisions about whether or not to disclose abuse when asked about it in health settings is important to ensuring that those experiencing violence are provided with access to services to support their safety and wellbeing. This study tested a model for women's decisions to disclose IPV in response to routine inquiry as part of antenatal assessment. Qualitative configurational analysis, suited to the study of causal pathways in complex social phenomena, was used to analyse interviews with 32 women who had experienced IPV in the past 12 months and who elected, when asked, to either disclose this to the midwife (n = 24) or not to do so (n = 8). Multiple pathways to disclosure were identified. While no single factor was necessary or sufficient for a decision to disclose, direct asking and care, defined as showing interest and a non-judgemental attitude, were found to be key conditions. The absence of care was also central to decisions not to disclose, as were perceptions of relevance of the abuse at the time of assessment. Confirming key elements of the original model, these findings highlight the importance of being asked about abuse in women's decisions to disclose, as well as the relational nature of this process. Trauma-informed practices for identifying and responding to intimate partner violence are needed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Sheet Hydroforming Process Numerical Model Improvement Through Experimental Results Analysis

    NASA Astrophysics Data System (ADS)

    Gabriele, Papadia; Antonio, Del Prete; Alfredo, Anglani

    2010-06-01

    The increasing application of numerical simulation in metal forming field has helped engineers to solve problems one after another to manufacture a qualified formed product reducing the required time [1]. Accurate simulation results are fundamental for the tooling and the product designs. The wide application of numerical simulation is encouraging the development of highly accurate simulation procedures to meet industrial requirements. Many factors can influence the final simulation results and many studies have been carried out about materials [2], yield criteria [3] and plastic deformation [4,5], process parameters [6] and their optimization. In order to develop a reliable hydromechanical deep drawing (HDD) numerical model the authors have been worked out specific activities based on the evaluation of the effective stiffness of the blankholder structure [7]. In this paper after an appropriate tuning phase of the blankholder force distribution, the experimental activity has been taken into account to improve the accuracy of the numerical model. In the first phase, the effective capability of the blankholder structure to transfer the applied load given by hydraulic actuators to the blank has been explored. This phase ended with the definition of an appropriate subdivision of the blankholder active surface in order to take into account the effective pressure map obtained for the given loads configuration. In the second phase the numerical results obtained with the developed subdivision have been compared with the experimental data of the studied model. The numerical model has been then improved, finding the best solution for the blankholder force distribution.

  6. Theoretical and Experimental Investigation of Random Gust Loads Part I : Aerodynamic Transfer Function of a Simple Wing Configuration in Incompressible Flow

    NASA Technical Reports Server (NTRS)

    Hakkinen, Raimo J; Richardson, A S , Jr

    1957-01-01

    Sinusoidally oscillating downwash and lift produced on a simple rigid airfoil were measured and compared with calculated values. Statistically stationary random downwash and the corresponding lift on a simple rigid airfoil were also measured and the transfer functions between their power spectra determined. The random experimental values are compared with theoretically approximated values. Limitations of the experimental technique and the need for more extensive experimental data are discussed.

  7. Thermodiffusion in multicomponent hydrocarbon mixtures: Experimental investigations and computational analysis.

    PubMed

    VanVaerenbergh, Stefan; Srinivasan, Seshasai; Saghir, M Ziad

    2009-09-21

    In an unprecedented experimental investigation, a ternary and a four component hydrocarbon mixture at high pressure have been studied in a nearly convection free environment to understand the thermodiffusion process. A binary mixture has also been investigated in this environment. Experimental investigations of the three mixtures have been conducted in space onboard the spacecraft FOTON-M3 thereby isolating the gravity-induced convection that otherwise interferes with thermodiffusion experiments on Earth. The experimental results have also been used to test a thermodiffusion model that has been calibrated based on the results of previous experimental investigations. It was found that with an increase in the number of components in the mixtures, the performance of the thermodiffusion model deteriorated. Computational analysis was also made to estimate the possible sources of errors. Simulations showed that the vibrations of the spacecraft could influence the estimates of thermodiffusion factors. It was also found that they are sensitive to slight variations in the temperature of the mixture.

  8. Thermodiffusion in multicomponent hydrocarbon mixtures: Experimental investigations and computational analysis

    NASA Astrophysics Data System (ADS)

    VanVaerenbergh, Stefan; Srinivasan, Seshasai; Saghir, M. Ziad

    2009-09-01

    In an unprecedented experimental investigation, a ternary and a four component hydrocarbon mixture at high pressure have been studied in a nearly convection free environment to understand the thermodiffusion process. A binary mixture has also been investigated in this environment. Experimental investigations of the three mixtures have been conducted in space onboard the spacecraft FOTON-M3 thereby isolating the gravity-induced convection that otherwise interferes with thermodiffusion experiments on Earth. The experimental results have also been used to test a thermodiffusion model that has been calibrated based on the results of previous experimental investigations. It was found that with an increase in the number of components in the mixtures, the performance of the thermodiffusion model deteriorated. Computational analysis was also made to estimate the possible sources of errors. Simulations showed that the vibrations of the spacecraft could influence the estimates of thermodiffusion factors. It was also found that they are sensitive to slight variations in the temperature of the mixture.

  9. Parametric and experimental analysis using a power flow approach

    NASA Technical Reports Server (NTRS)

    Cuschieri, J. M.

    1990-01-01

    A structural power flow approach for the analysis of structure-borne transmission of vibrations is used to analyze the influence of structural parameters on transmitted power. The parametric analysis is also performed using the Statistical Energy Analysis approach and the results are compared with those obtained using the power flow approach. The advantages of structural power flow analysis are demonstrated by comparing the type of results that are obtained by the two analytical methods. Also, to demonstrate that the power flow results represent a direct physical parameter that can be measured on a typical structure, an experimental study of structural power flow is presented. This experimental study presents results for an L shaped beam for which an available solution was already obtained. Various methods to measure vibrational power flow are compared to study their advantages and disadvantages.

  10. Viscoplastic analysis of an experimental cylindrical thrust chamber liner

    NASA Technical Reports Server (NTRS)

    Arya, Vinod K.; Arnold, Steven M.

    1991-01-01

    A viscoplastic stress-strain analysis of an experimental cylindrical thrust chamber is presented. A viscoelastic constitutive model incorporating a single internal state variable that represents kinematic hardening was employed to investigate whether such a viscoplastic model could predict the experimentally observed behavior of the thrust chamber. Two types of loading cycles were considered: a short cycle of 3.5 sec. duration that corresponded to the experiments, and an extended loading cycle of 485.1 sec. duration that is typical of the Space Shuttle Main Engine (SSME) operating cycle. The analysis qualitatively replicated the deformation behavior of the component as observed in experiments designed to simulate SSME operating conditions. The analysis also showed that the mode and location in the component may depend on the loading cycle. The results indicate that using viscoplastic models for structural analysis can lead to a more realistic life assessment of thrust chambers.

  11. Math and Reading Differences between 6-8 and K-8 Grade Span Configurations: A Multiyear, Statewide Analysis

    ERIC Educational Resources Information Center

    Clark, David M.; Slate, John R.; Combs, Julie P.; Moore, George W.

    2013-01-01

    We analyzed the effect of grade span configurations (i.e., 6-8 versus K-8) on reading and math performance in Texas public schools for the last 5 school years. Participants in this study were 628 Texas schools (i.e., 314 middle schools and 314 K-8 schools) distributed across the 5 school years examined. Schools configured as K-8 schools were…

  12. The "Journal of the Experimental Analysis of Behavior" at Fifty

    ERIC Educational Resources Information Center

    Laties, Victor G.

    2008-01-01

    The "Journal of the Experimental Analysis of Behavior" was founded in 1958 by a group of male psychologists, mainly from the northeastern USA and connected with either Harvard or Columbia. Fifty years later about 20% of both editors and authors reside outside this country and almost the same proportion is women. Other changes in the…

  13. Knowledge Management for the Analysis of Complex Experimentation.

    ERIC Educational Resources Information Center

    Maule, R.; Schacher, G.; Gallup, S.

    2002-01-01

    Describes a knowledge management system that was developed to help provide structure for dynamic and static data and to aid in the analysis of complex experimentation. Topics include quantitative and qualitative data; mining operations using artificial intelligence techniques; information architecture of the system; and transforming data into…

  14. Mathematical Models and the Experimental Analysis of Behavior

    ERIC Educational Resources Information Center

    Mazur, James E.

    2006-01-01

    The use of mathematical models in the experimental analysis of behavior has increased over the years, and they offer several advantages. Mathematical models require theorists to be precise and unambiguous, often allowing comparisons of competing theories that sound similar when stated in words. Sometimes different mathematical models may make…

  15. A Realistic Experimental Design and Statistical Analysis Project

    ERIC Educational Resources Information Center

    Muske, Kenneth R.; Myers, John A.

    2007-01-01

    A realistic applied chemical engineering experimental design and statistical analysis project is documented in this article. This project has been implemented as part of the professional development and applied statistics courses at Villanova University over the past five years. The novel aspects of this project are that the students are given a…

  16. Analyzing Math-to-Mastery through Brief Experimental Analysis

    ERIC Educational Resources Information Center

    Everett, Gregory E.; Swift, Honora S.; McKenney, Elizabeth L. W.; Jewell, Jeremy D.

    2016-01-01

    The current study evaluated the effectiveness of individualized math-to-mastery (MTM) interventions, selected though brief experimental analysis (BEA), at increasing math fluency skills for three elementary-aged females. As MTM has only been investigated as a multicomponent intervention, the present study utilized BEA to identify those specific…

  17. Analyzing Math-to-Mastery through Brief Experimental Analysis

    ERIC Educational Resources Information Center

    Everett, Gregory E.; Swift, Honora S.; McKenney, Elizabeth L. W.; Jewell, Jeremy D.

    2016-01-01

    The current study evaluated the effectiveness of individualized math-to-mastery (MTM) interventions, selected though brief experimental analysis (BEA), at increasing math fluency skills for three elementary-aged females. As MTM has only been investigated as a multicomponent intervention, the present study utilized BEA to identify those specific…

  18. Selecting Intervention Strategies: Using Brief Experimental Analysis for Mathematics Problems

    ERIC Educational Resources Information Center

    Codding, Robin S.; Baglici, Stephanie; Gottesman, Dana; Johnson, Mitchelle; Kert, Allison Schaffer; Lebeouf, Patricia

    2009-01-01

    Although brief experimental analysis (BEA) procedures have been effective for aiding instructional decision making in the area of reading, there is a paucity of research extending this technology to mathematics. This study extends the literature on mathematics BEA by using an abridged data series that compares skill- and performance-based…

  19. Mathematical Models and the Experimental Analysis of Behavior

    ERIC Educational Resources Information Center

    Mazur, James E.

    2006-01-01

    The use of mathematical models in the experimental analysis of behavior has increased over the years, and they offer several advantages. Mathematical models require theorists to be precise and unambiguous, often allowing comparisons of competing theories that sound similar when stated in words. Sometimes different mathematical models may make…

  20. A Realistic Experimental Design and Statistical Analysis Project

    ERIC Educational Resources Information Center

    Muske, Kenneth R.; Myers, John A.

    2007-01-01

    A realistic applied chemical engineering experimental design and statistical analysis project is documented in this article. This project has been implemented as part of the professional development and applied statistics courses at Villanova University over the past five years. The novel aspects of this project are that the students are given a…

  1. Experimental Investigation of the Influence of Joint Geometric Configurations on the Mechanical Properties of Intermittent Jointed Rock Models Under Cyclic Uniaxial Compression

    NASA Astrophysics Data System (ADS)

    Liu, Yi; Dai, Feng; Fan, Pengxian; Xu, Nuwen; Dong, Lu

    2017-06-01

    Intermittent joints in rock mass are quite sensitive to cyclic loading conditions. Understanding the fatigue mechanical properties of jointed rocks is beneficial for rational design and stability analysis of rock engineering projects. This study experimentally investigated the influences of joint geometry (i.e., dip angle, persistency, density and spacing) on the fatigue mechanism of synthetic jointed rock models. Our results revealed that the stress-strain curve of jointed rock under cyclic loadings is dominated by its curve under monotonic uniaxial loadings; the terminal strain in fatigue curve is equal to the post-peak strain corresponding to the maximum cyclic stress in the monotonic stress-strain curve. The four joint geometrical parameters studied significantly affect the fatigue properties of jointed rocks, including the irreversible strains, the fatigue deformation modulus, the energy evolution, the damage variable and the crack coalescence patterns. The higher the values of the geometrical parameters, the lower the elastic energy stores in this jointed rock, the higher the fatigue damage accumulates in the first few cycles, and the lower the fatigue life. The elastic energy has certain storage limitation, at which the fatigue failure occurs. Two basic micro-cracks, i.e., tensile wing crack and shear crack, are observed in cyclic loading and unloading tests, which are controlled principally by joint dip angle and persistency. In general, shear cracks only occur in the jointed rock with higher dip angle or higher persistency, and the jointed rock is characterized by lower fatigue strength, larger damage variable and lower fatigue life.

  2. Experimental analysis of optical limiting properties of Cu nanoclusters

    NASA Astrophysics Data System (ADS)

    Wang, Y. H.; Wang, Y. M.; Han, C. J.; Lu, J. D.; Ji, L. L.

    2010-06-01

    Optical nonlinearities of Cu nanoclusters prepared by implanting Cu ions into silica at 180 keV with dose of 1×10 17 ions/cm 2 have been studied. The third-order nonlinear optical properties of the nanoclusters were measured at 1064 nm excitations using Z-scan technique. Results of the investigation of nonlinear refraction by the off-axis Z-scan configuration were presented and the mechanisms responsible for the nonlinear response were discussed. Innovative point of this paper is that we carried out curve fitting analysis, which is based on MATLAB features, for Cu optical limiting experiment. Our results showed that Cu nanoclusters have refractive optical limiting effect at 1064 nm.

  3. Combined experimental and numerical analysis of a bubbly liquid metal flow

    NASA Astrophysics Data System (ADS)

    Krull, B.; Strumpf, E.; Keplinger, O.; Shevchenko, N.; Fröhlich, J.; Eckert, S.; Gerbeth, G.

    2017-07-01

    The paper proposes a combined experimental and numerical procedure for the investigation of bubbly liquid-metal flows. It describes the application to a model configuration consisting of a recirculating GaInSn flow driven by an argon bubble chain. The experimental methods involve X-ray measurements to detect the bubbles and UDV measurements to gain velocity information about the liquid metal. The chosen numerical method is an immersed boundary method extended to deformable bubbles. The model configuration includes typical phenomena occurring in industrial applications and allows insight into the physics of bubbly liquid-metal flows. It constitutes an attractive test case for assessing further experimental and numerical methods.

  4. Dose distribution of gamma radiation in a new geometric configuration of a standard carton date package and its experimental application for disinfestation of packed dates

    NASA Astrophysics Data System (ADS)

    Ahmed, M. S. H.; Al-Taweel, A. A.; Hameed, A. A.

    1994-06-01

    A new geometrical configuration composed of three standard carton boxes (SCBs) full with polyethylene bags (PBs), where each bag contains 1 kg of date, was placed on a single turntable of Gammabeam-650 and irradiated with low doses. The mean "radiation absorbed dose" for disinfestation of this geometrical unit at 15 equally distributed positions (Fricke dosimeters) inside 3 SCBs put on a single turntable was calculated to be 0.46 ± 0.20 kGy and dose uniformity ratio ( U) = 1.0019/0.2500 = 4.00. The development and genetic tests carried out on insects found in the PBs 1-2 days after irradiation resulted in that all insects were completely sterile and died within a short period of time. No sign of any reinfestation was recorded at all in the treated packages even after 30 days of storage in an insectory. Apparently the prevention of insects from invading and/or penetrating the date packages is due mainly to the new combination of standard carton boxes that are widely used for commercial purposes and hermetically heat-sealed polyethylene bags of dates in addition to the entire prevention of reproduction induced by the "low" doses of γ radiation. Therefore, by using similar geometrical configuration, 18 big standard carton date packages can be simultaneously disinfected, using the same range of doses or so, by utilizing all the 6 turntables inside the radiation chamber of the Gammabeam-650 irradiation facility.

  5. Principles of Experimental Design for Big Data Analysis

    PubMed Central

    Drovandi, Christopher C; Holmes, Christopher; McGree, James M; Mengersen, Kerrie; Richardson, Sylvia; Ryan, Elizabeth G

    2016-01-01

    Big Datasets are endemic, but are often notoriously difficult to analyse because of their size, heterogeneity and quality. The purpose of this paper is to open a discourse on the potential for modern decision theoretic optimal experimental design methods, which by their very nature have traditionally been applied prospectively, to improve the analysis of Big Data through retrospective designed sampling in order to answer particular questions of interest. By appealing to a range of examples, it is suggested that this perspective on Big Data modelling and analysis has the potential for wide generality and advantageous inferential and computational properties. We highlight current hurdles and open research questions surrounding efficient computational optimisation in using retrospective designs, and in part this paper is a call to the optimisation and experimental design communities to work together in the field of Big Data analysis. PMID:28883686

  6. Principles of Experimental Design for Big Data Analysis.

    PubMed

    Drovandi, Christopher C; Holmes, Christopher; McGree, James M; Mengersen, Kerrie; Richardson, Sylvia; Ryan, Elizabeth G

    2017-08-01

    Big Datasets are endemic, but are often notoriously difficult to analyse because of their size, heterogeneity and quality. The purpose of this paper is to open a discourse on the potential for modern decision theoretic optimal experimental design methods, which by their very nature have traditionally been applied prospectively, to improve the analysis of Big Data through retrospective designed sampling in order to answer particular questions of interest. By appealing to a range of examples, it is suggested that this perspective on Big Data modelling and analysis has the potential for wide generality and advantageous inferential and computational properties. We highlight current hurdles and open research questions surrounding efficient computational optimisation in using retrospective designs, and in part this paper is a call to the optimisation and experimental design communities to work together in the field of Big Data analysis.

  7. Theoretical Analysis of the F1-ATPase Experimental Data

    PubMed Central

    Perez-Carrasco, Ruben; Sancho, J.M.

    2010-01-01

    Abstract F1-ATPase is a rotatory molecular motor fueled by ATP nucleotides. Different loads can be attached to the motor axis to show that it rotates in main discrete steps of 120° with substeps of ∼80° and 40°. Experimental data show the dependence on the mean rotational velocity ω with respect to the external control parameters: the nucleotide concentration [ATP] and the friction of the load γL. In this work we present a theoretical analysis of the experimental data whose main results are: 1), A derivation of a simple analytical formula for ω([ATP], γL) that compares favorably with experiments; 2), The introduction of a two-state flashing ratchet model that exhibits experimental phenomenology of a greater specificity than has been, to our knowledge, previously available; 3), The derivation of an argument to obtain the values of the substep sizes; 4), An analysis of the energy constraints of the model; and 5), The theoretical analysis of the coupling ratio between the ATP consumed and the success of a forward step. We also discuss the compatibility of our approach with recent experimental observations. PMID:20513403

  8. An Experimental Metagenome Data Management and AnalysisSystem

    SciTech Connect

    Markowitz, Victor M.; Korzeniewski, Frank; Palaniappan, Krishna; Szeto, Ernest; Ivanova, Natalia N.; Kyrpides, Nikos C.; Hugenholtz, Philip

    2006-03-01

    The application of shotgun sequencing to environmental samples has revealed a new universe of microbial community genomes (metagenomes) involving previously uncultured organisms. Metagenome analysis, which is expected to provide a comprehensive picture of the gene functions and metabolic capacity of microbial community, needs to be conducted in the context of a comprehensive data management and analysis system. We present in this paper IMG/M, an experimental metagenome data management and analysis system that is based on the Integrated Microbial Genomes (IMG) system. IMG/M provides tools and viewers for analyzing both metagenomes and isolate genomes individually or in a comparative context.

  9. Analytical and experimental analysis of tube coil heat exchanger

    NASA Astrophysics Data System (ADS)

    Smusz, R.

    2016-09-01

    The paper presents the analytical and experimental analysis of heat transfer for the finned tube coil heat exchanger immersed in thermal storage tank. The tank is equipped with three helical-shaped heating coils and cylindrical- shaped stratification device. Two coils, upper and lower, use the water as a heating medium. The third, double wall heat exchanger coil, located at the bottom head on the tank is filled by the refrigerant (freon). Calculations of thermal power of water coil were made. Correlations of heat transfer coefficients in curved tubes were applied. In order to verify the analytical calculations the experimental studies of heat transfer characteristic for coil heat exchanger were performed.

  10. Refining the Experimental Analysis of Academic Skills Deficits: Part II. Use of Brief Experimental Analysis to Evaluate Reading Fluency Treatments

    ERIC Educational Resources Information Center

    Daly, Edward J., III; Bonfiglio, Christine M.; Mattson, Tara; Persampieri, Michael; Foreman-Yates, Kristin

    2006-01-01

    The technology of brief experimental analysis is just beginning to be used for identification of effective treatments for individual students who experience difficulty with oral reading fluency. In this study, the effect of a reading fluency treatment package was examined on easy and hard passages, and generalization was assessed on passages with…

  11. Unstructured Grid Euler Method Assessment for Longitudinal and Lateral/Directional Stability Analysis of the HSR Reference H Configuration at Transonic Speeds

    NASA Technical Reports Server (NTRS)

    Ghaffari, Farhad

    1999-01-01

    Transonic Euler computations, based on unstructured grid methodology, are performed for a proposed High Speed Civil Transport (HSCT) configuration, designated as the Reference H configuration within the High Speed Research (HSR) Program. The predicted results are correlated with appropriate experimental wind-tunnel data for the baseline configuration with and without control surface deflections for a range of angle of attack at M(sub infinity) = 0.95. Good correlations between the predictions and measured data have been obtained for the longitudinal aerodynamic characteristics of the baseline configuration. The incremental effects in the longitudinal aerodynamic characteristics due to horizontal rail deflections as well as wing leading-edge and trailing-edge flap deflections have also been predicted reasonably well. Computational results and correlations with data are also presented for the lateral and directional stability characteristics for a range of angle of attack at a constant sideslip angle as well as a range of sideslip angles at a constant angle of attack. In addition, the results are presented to assess the computational method performance and convergence characteristics.

  12. Analysis and optimization of three main organic Rankine cycle configurations using a set of working fluids with different thermodynamic behaviors

    NASA Astrophysics Data System (ADS)

    Hamdi, Basma; Mabrouk, Mohamed Tahar; Kairouani, Lakdar; Kheiri, Abdelhamid

    2017-06-01

    Different configurations of organic Rankine cycle (ORC) systems are potential thermodynamic concepts for power generation from low grade heat. The aim of this work is to investigate and optimize the performances of the three main ORC systems configurations: basic ORC, ORC with internal heat exchange (IHE) and regenerative ORC. The evaluation for those configurations was performed using seven working fluids with typical different thermodynamic behaviours (R245fa, R601a, R600a, R227ea, R134a, R1234ze and R1234yf). The optimization has been performed using a genetic algorithm under a comprehensive set of operative parameters such as the fluid evaporating temperature, the fraction of flow rate or the pressure at the steam extracting point in the turbine. Results show that there is no general best ORC configuration for all those fluids. However, there is a suitable configuration for each fluid. Contribution to the topical issue "Materials for Energy harvesting, conversion and storage II (ICOME 2016)", edited by Jean-Michel Nunzi, Rachid Bennacer and Mohammed El Ganaoui

  13. A Simple Synthesis of Alliin and allo-Alliin: X-ray Diffraction Analysis and Determination of Their Absolute Configurations.

    PubMed

    Hakamata, Wataru; Koyama, Ryosuke; Tanida, Mizuki; Haga, Tomomi; Hirano, Takako; Akao, Makoto; Kumagai, Hitomi; Nishio, Toshiyuki

    2015-12-23

    A simple method for the isolation of the bioactive compound alliin from garlic, as well as a method for the synthesis of diastereomerically pure alliin and allo-alliin on a preparative laboratory scale, was developed. The absolute configuration of the sulfur atom in alliin and allo-alliin was assigned on the basis of enzyme reactivity, optical rotatory dispersion, and circular dichroism analyses. A comparison of the results from these analyses, in combination with an X-ray diffraction study on a protected allo-alliin derivative, revealed S and R configurations of the sulfur atoms in alliin and allo-alliin, respectively. In addition, the same (1)H NMR spectrum was observed for synthetic and natural alliin. The absolute configuration of natural alliin was assigned for the first time on the basis of the NMR spectrum and X-ray coordinates.

  14. A Primer on Bayesian Analysis for Experimental Psychopathologists.

    PubMed

    Krypotos, Angelos-Miltiadis; Blanken, Tessa F; Arnaudova, Inna; Matzke, Dora; Beckers, Tom

    2017-01-01

    The principal goals of experimental psychopathology (EPP) research are to offer insights into the pathogenic mechanisms of mental disorders and to provide a stable ground for the development of clinical interventions. The main message of the present article is that those goals are better served by the adoption of Bayesian statistics than by the continued use of null-hypothesis significance testing (NHST). In the first part of the article we list the main disadvantages of NHST and explain why those disadvantages limit the conclusions that can be drawn from EPP research. Next, we highlight the advantages of Bayesian statistics. To illustrate, we then pit NHST and Bayesian analysis against each other using an experimental data set from our lab. Finally, we discuss some challenges when adopting Bayesian statistics. We hope that the present article will encourage experimental psychopathologists to embrace Bayesian statistics, which could strengthen the conclusions drawn from EPP research.

  15. Experimental analysis of a joint free space cryptosystem

    NASA Astrophysics Data System (ADS)

    Ramírez, John Fredy Barrera; Osorio, Alexis Jaramillo; Zea, Alejandro Vélez; Torroba, Roberto

    2016-08-01

    In this paper, we analyze a joint free space cryptosystem scheme implemented in an actual laboratory environment. In this encrypting architecture, the object to be encoded and the security key are placed side by side in the input plane without optical elements between the input and the output planes. In order to get the encrypted information, the joint Fresnel power distribution JFPD coming from the input plane is registered in a CMOS camera. The information of the encrypting key is registered with an off axis Fresnel holographic setup. The data registered with the experimental setup is digitally filtered to obtain the encrypted object and the encryption key. In addition, we explore the performance of the experimental system as a function of the object-camera and key-camera distances, which are two new parameters of interest. These parameters become available as a result of developing this encrypting scheme. The theoretical and experimental analysis shows the validity and applicability of the cryptosystem.

  16. Feasibility of combining linear theory and impact theory methods for the analysis and design of high speed configurations

    NASA Technical Reports Server (NTRS)

    Brooke, D.; Vondrasek, D. V.

    1978-01-01

    The aerodynamic influence coefficients calculated using an existing linear theory program were used to modify the pressures calculated using impact theory. Application of the combined approach to several wing-alone configurations shows that the combined approach gives improved predictions of the local pressure and loadings over either linear theory alone or impact theory alone. The approach not only removes most of the short-comings of the individual methods, as applied in the Mach 4 to 8 range, but also provides the basis for an inverse design procedure applicable to high speed configurations.

  17. Theoretical and experimental analysis of double-pass ytterbium-doped fiber amplifier

    NASA Astrophysics Data System (ADS)

    Zhang, Pengfei; Su, Rongtao; Huang, Long; Du, Daiyan; Yang, Lijia

    2016-11-01

    We theoretically and experimentally demonstrate a double-pass ytterbium-doped fiber amplifier. First, we numerically analyze the impact of fiber length on the amplifier. In our experiment, a laser seed with output power of 100 μW and wavelength of 1064 nm is amplified to 51.2 mW with a signal gain of 27.1 dB. With this double-pass configuration, amplified spontaneous emission (ASE) is effectively suppressed to more than 30 dB. Compared with single pass configuration, it is found that double-pass amplification configuration enhances the gain coefficient and improves the signal-to-noise ratio.

  18. Static and dynamic experimental analysis of the galloping stability of porous H-section beams.

    PubMed

    Gandia, F; Meseguer, J; Sanz-Andrés, A

    2014-01-01

    The phenomenon of self-induced vibrations of prismatic beams in a cross-flow has been studied for decades, but it is still of great interest due to their important effects in many different industrial applications. This paper presents the experimental study developed on a prismatic beam with H-section. The aim of this analysis is to add some additional insight into the behaviour of the flow around this type of bodies, in order to reduce galloping and even to avoid it. The influence of some relevant geometrical parameters that define the H-section on the translational galloping behaviour of these beams has been analysed. Wind loads coefficients have been measured through static wind tunnel tests and the Den Hartog criterion applied to elucidate the influence of geometrical parameters on the galloping properties of the bodies under consideration. These results have been completed with surface pressure distribution measurements and, besides, dynamic tests have been also performed to verify the static criterion. Finally, the morphology of the flow past the tested bodies has been visualised by using smoke visualization techniques. Since the rectangular section beam is a limiting case of the H-section configuration, the results here obtained are compared with the ones published in the literature concerning rectangular configurations; the agreement is satisfactory.

  19. A novel self-powered MR damper: theoretical and experimental analysis

    NASA Astrophysics Data System (ADS)

    Xinchun, Guan; Yonghu, Huang; Yi, Ru; Hui, Li; Jinping, Ou

    2015-10-01

    This paper presents a novel magnetorheological (MR) damper with a self-powered capability, which is proposed to have energy harvesting and MR damping technologies integrated into a single device. Vibration energy harvesting mechanisms were adopted, based on ball-screw mechanisms and a rotary permanent magnet dc generator, to convert the external vibration energy into electrical energy to power the MR damping unit. The configuration and operating principles of the proposed self-powered MR damper were presented. Considering the core loss effect on the magnetic field, a theoretical analysis of the proposed MR damper was carried out and a mechanical model was developed. Finally, a prototype with a capacity of 10 kN was fabricated and experimentally investigated in both the direct-supply mode and the supply-with-rectifier mode. The results indicated that the proposed configuration is feasible and that both modes can realize good self-adaptability of the MR damping force. However, the direct-supply mode has a sag effect in the force-displacement curve and provides a lower energy-dissipating capacity than the direct-supply mode does under the same conditions.

  20. Static and Dynamic Experimental Analysis of the Galloping Stability of Porous H-Section Beams

    PubMed Central

    Gandia, F.; Meseguer, J.; Sanz-Andrés, A.

    2014-01-01

    The phenomenon of self-induced vibrations of prismatic beams in a cross-flow has been studied for decades, but it is still of great interest due to their important effects in many different industrial applications. This paper presents the experimental study developed on a prismatic beam with H-section. The aim of this analysis is to add some additional insight into the behaviour of the flow around this type of bodies, in order to reduce galloping and even to avoid it. The influence of some relevant geometrical parameters that define the H-section on the translational galloping behaviour of these beams has been analysed. Wind loads coefficients have been measured through static wind tunnel tests and the Den Hartog criterion applied to elucidate the influence of geometrical parameters on the galloping properties of the bodies under consideration. These results have been completed with surface pressure distribution measurements and, besides, dynamic tests have been also performed to verify the static criterion. Finally, the morphology of the flow past the tested bodies has been visualised by using smoke visualization techniques. Since the rectangular section beam is a limiting case of the H-section configuration, the results here obtained are compared with the ones published in the literature concerning rectangular configurations; the agreement is satisfactory. PMID:25541626

  1. Spectral Analysis and Experimental Modeling of Ice Accretion Roughness

    NASA Technical Reports Server (NTRS)

    Orr, D. J.; Breuer, K. S.; Torres, B. E.; Hansman, R. J., Jr.

    1996-01-01

    A self-consistent scheme for relating wind tunnel ice accretion roughness to the resulting enhancement of heat transfer is described. First, a spectral technique of quantitative analysis of early ice roughness images is reviewed. The image processing scheme uses a spectral estimation technique (SET) which extracts physically descriptive parameters by comparing scan lines from the experimentally-obtained accretion images to a prescribed test function. Analysis using this technique for both streamwise and spanwise directions of data from the NASA Lewis Icing Research Tunnel (IRT) are presented. An experimental technique is then presented for constructing physical roughness models suitable for wind tunnel testing that match the SET parameters extracted from the IRT images. The icing castings and modeled roughness are tested for enhancement of boundary layer heat transfer using infrared techniques in a "dry" wind tunnel.

  2. Experimental Design and Evaluation of Bounded Rationality Using Dimensional Analysis

    DTIC Science & Technology

    1989-05-01

    dimensional analysis; experimental design; cognitive s ork load. pressure is very high), decisionmakers are likely to make INTRODUCION mistakes so...Homogeneity, the following will be shown. The following procedure was used to analyze set of simultaneous algebraic equations must be satisfied. the data...Information theory. H is constant for the by solving the set of algebraic equations, we obtain: experiment, and G depends on the algorithm used by a

  3. Evaluation of the changes in midfacial configuration after face mask therapy in skeletal Class III growing patients by morphometric analysis techniques.

    PubMed

    Chang, Jenny Zwei-Chieng; Chang, Hong-Po; Chen, Yi-Jane; Yao, Jane Chung-Chen; Liu, Pao-Hsin; Chang, Frank Hsin-Fu

    2005-12-01

    The prevalence of Angle Class III malocclusion is relatively high in Taiwan. For children who suffer from maxillary retrognathia, face mask therapy is a promising treatment modality. The purpose of this study was to evaluate the changes in midfacial configuration after face mask therapy in skeletal Class III growing patients by morphometric analysis techniques. Thirty children who had been treated with face masks were compared with a group of 30 gender-matched, age-matched, observation period-matched, and craniofacial configuration-matched subjects with untreated Class III malocclusions. Average geometries, scaled to an equivalent size, were generated by means of Procrustes analysis. Graphical analysis, utilizing thin-plate spline analysis and strain tensor methods, was performed for localization of differences in shape and size changes. Maximum and minimum principal extensions were drawn to express the directions of shape change. Maxillary protraction-induced changes resulted from a combination of both orthopedic and dental effects. A significant increase in size (7.7% to 9.9%) was noted at the supero-anterior region of the midfacial configuration (rhinion-orbitale-midpalatal point-anterior nasal spine) when subjected to an extraoral traction force; 7.7% to 12.1% of increase in size and 14.4% to 33.4% of change in shape were found at the anterior portion of the maxillary alveolar bone. The directions and amount of principal strain tensors could express the magnitudes and directions of morphological changes within the midfacial complex in an efficient way. We conclude that morphometric analysis techniques can be used to evaluate the changes in midfacial configuration after face mask therapy and can provide a valuable supplement for conventional cephalometric analysis.

  4. The experimental analysis of human sexual arousal: Some recent developments

    PubMed Central

    Roche, Bryan; Barnes, Dermot

    1998-01-01

    Experimental analyses of human sexual arousal have been decidedly sparse. Recent developments in the analysis of derived relational responding, however, have opened the way for a modern behavior-analytic treatment of complex or “novel” human behavior, including specific instances of human sexual arousal. The current article examines some of these developments and their relevance to the analysis of emotional behavior, with a focus on sexual arousal. Recent research that has examined the acquisition of sexual stimulus functions within a relational frame paradigm is then outlined. Finally, a series of relational frame interpretations of a variety of human sexual arousal phenomena is offered. PMID:22478296

  5. Regression Model Optimization for the Analysis of Experimental Data

    NASA Technical Reports Server (NTRS)

    Ulbrich, N.

    2009-01-01

    A candidate math model search algorithm was developed at Ames Research Center that determines a recommended math model for the multivariate regression analysis of experimental data. The search algorithm is applicable to classical regression analysis problems as well as wind tunnel strain gage balance calibration analysis applications. The algorithm compares the predictive capability of different regression models using the standard deviation of the PRESS residuals of the responses as a search metric. This search metric is minimized during the search. Singular value decomposition is used during the search to reject math models that lead to a singular solution of the regression analysis problem. Two threshold dependent constraints are also applied. The first constraint rejects math models with insignificant terms. The second constraint rejects math models with near-linear dependencies between terms. The math term hierarchy rule may also be applied as an optional constraint during or after the candidate math model search. The final term selection of the recommended math model depends on the regressor and response values of the data set, the user s function class combination choice, the user s constraint selections, and the result of the search metric minimization. A frequently used regression analysis example from the literature is used to illustrate the application of the search algorithm to experimental data.

  6. Radiant-interchange Configuration Factors

    NASA Technical Reports Server (NTRS)

    Hamilton, D C :; Morgan, W R

    1952-01-01

    A study is presented of the geometric configuration factors required for computing radiant heat transfer between opaque surfaces separated by a nonabsorbing medium and various methods of determining the configuration factors are discussed. Configuration-factor solutions available in the literature have been checked and the more complicated equations are presented as families of curves. Cases for point, line, and finite-area sources are worked out over a wide range of geometric proportions. These cases include several new configurations involving rectangles, triangles, and cylinders of finite length which are integrated and tabulated. An analysis is presented, in which configuration factors are employed of the radiant heat transfer to the rotor blades of a typical gas turbine under different conditions of temperature and pressure. (author)

  7. Investigation of Advanced Counterrotation Blade Configuration Concepts for High Speed Turboprop Systems. Task 2: Unsteady Ducted Propfan Analysis

    NASA Technical Reports Server (NTRS)

    Hall, Edward J.; Delaney, Robert A.; Bettner, James L.

    1991-01-01

    The primary objective was the development of a time dependent 3-D Euler/Navier-Stokes aerodynamic analysis to predict unsteady compressible transonic flows about ducted and unducted propfan propulsion systems at angle of attack. The resulting computer codes are referred to as Advanced Ducted Propfan Analysis Codes (ADPAC). A computer program user's manual is presented for the ADPAC. Aerodynamic calculations were based on a four stage Runge-Kutta time marching finite volume solution technique with added numerical dissipation. A time accurate implicit residual smoothing operator was used for unsteady flow predictions. For unducted propfans, a single H-type grid was used to discretize each blade passage of the complete propeller. For ducted propfans, a coupled system of five grid blocks utilizing an embedded C grid about the cowl leading edge was used to discretize each blade passage. Grid systems were generated by a combined algebraic/elliptic algorithm developed specifically for ducted propfans. Numerical calculations were compared with experimental data for both ducted and unducted flows.

  8. Experimental aerodynamic characteristics of two V/STOL fighter/attack aircraft configurations at Mach numbers from 0.4 to 1.4

    NASA Technical Reports Server (NTRS)

    Nelms, W. P.; Durston, D. A.; Lummus, J. R.

    1980-01-01

    A wind tunnel test was conducted to measure the aerodynamic characteristics of two horizontal attitude takeoff and landing V/STOL fighter/attack aircraft concepts. In one concept, a jet diffuser ejector was used for the vertical lift system; the other used a remote augmentation lift system (RALS). Wind tunnel tests to investigate the aerodynamic uncertainties and to establish a data base for these types of concepts were conducted over a Mach number range from 0.2 to 2.0. The present report covers tests, conducted in the 11 foot transonic wind tunnel, for Mach numbers from 0.4 to 1.4. Detailed effects of varying the angle of attack (up to 27 deg), angle of sideslip (-4 deg to +8 deg), Mach number, Reynolds number, and configuration buildup were investigated. In addition, the effects of wing trailing edge flap deflections, canard incidence, and vertical tail deflections were explored. Variable canard longitudinal location and different shapes of the inboard nacelle body strakes were also investigated.

  9. Experimental analysis of 7.62 mm hydrodynamic ram in containers

    NASA Astrophysics Data System (ADS)

    Deletombe, E.; Fabis, J.; Dupas, J.; Mortier, J. M.

    2013-02-01

    The design of fuel tanks with a reduced vulnerability with respect to hydrodynamic ram pressure (HRAM) effects is of an increasing need in the Civil (e.g. the Concorde accident), and Defence (military aircraft, unmanned vehicle systems) aircraft industries. The presented work concerns experimental research which aims at observing two hydraulic ram events - both induced by a 7.62 mm bullet shot in very different containers - throughout their various steps until the final collapse of the generated cavity, in order to study the nature of HRAM, the influence of the containers geometry, and to measure original dynamic data for numerical modelling developments and validation. For that purpose, test configurations and experimental results are described, documented and discussed. They concern two types of firing tests that were performed at ONERA using the NATO 7.62 mm projectile, respectively in the frame of ONERA (pool) and EUCLID (caisson) funded research projects. The authors concentrate on two topics: on the one hand, digital image analysis to measure the cavity geometry during its growth and collapse phases and, on the other hand, pressure measurements that catch the transient shock wave. The originality of the work consists in the fact that - compared with other published works - the phenomenon is studied up to tens of milliseconds in a very large pool for theoretical analysis of the bullet/liquid interactions only, and in a realistic fuel tank specimen to consider influence of boundary conditions onto the cavity characteristics (geometry, dynamics).

  10. Multilevel statistical models and the analysis of experimental data.

    PubMed

    Behm, Jocelyn E; Edmonds, Devin A; Harmon, Jason P; Ives, Anthony R

    2013-07-01

    Data sets from ecological experiments can be difficult to analyze, due to lack of independence of experimental units and complex variance structures. In addition, information of interest may lie in complicated contrasts among treatments, rather than direct output from statistical tests. Here, we present a statistical framework for analyzing data sets containing non-independent experimental units and differences in variance among treatments (heteroscedasticity) and apply this framework to experimental data on interspecific competition among three tadpole species. Our framework involves three steps: (1) use a multilevel regression model to calculate coefficients of treatment effects on response variables; (2) combine coefficients to quantify the strength of competition (the target information of our experiment); and (3) use parametric bootstrapping to calculate significance of competition strengths. We repeated this framework using three multilevel regression models to analyze data at the level of individual tadpoles, at the replicate level, and at the replicate level accounting for heteroscedasticity. Comparing results shows the need to correctly specify the statistical model, with the model that accurately accounts for heteroscedasticity leading to different conclusions from the other two models. This approach gives a single, comprehensive analysis of experimental data that can be used to extract informative biological parameters in a statistically rigorous way.

  11. Theoretical and experimental analysis of modern zoom lens design

    NASA Astrophysics Data System (ADS)

    Wang, Xiangyang; Liu, Weilin

    2017-02-01

    The need for stability of aberration and correction of images for a zoom lens system should be considered during zooming process. Our work presents detailed theoretical and experimental analysis of multiple moving zoom optical systems. In our work we propose methods to determine the basic parameters of such optical system, the focal lengths of each element of the objective lens and their mutual axial separation. Introduce two different image stability equation and cam curve design method to calculate basic parameters. This type of optical system is widely spread in practice mainly in the field of photographic lenses and in surveying instruments (theodolites, leveling instruments, etc.). Furthermore, the detailed analysis of aberration properties of such optical systems is performed and methods for measuring the focal lengths of individual elements and their mutual distance without the need for disassembling the investigated optical system are presented. Finally according to theoretical and experimental analysis of zoom lens system, a zoom optical system with effective focal length 27-220mm has been design, the first element of such system is fixed, and the other groups can move during zoom process to get a continuity consecutiveness effective focal length (EFL). Using the powerful optimization capabilities of optical design software CODE V; we get the imaging quality analysis such as the modulation transfer function (MTF) etc.

  12. Single photon laser altimeter data processing, analysis and experimental validation

    NASA Astrophysics Data System (ADS)

    Vacek, Michael; Peca, Marek; Michalek, Vojtech; Prochazka, Ivan

    2015-10-01

    Spaceborne laser altimeters are common instruments on-board the rendezvous spacecraft. This manuscript deals with the altimeters using a single photon approach, which belongs to the family of time-of-flight range measurements. Moreover, the single photon receiver part of the altimeter may be utilized as an Earth-to-spacecraft link enabling one-way ranging, time transfer and data transfer. The single photon altimeters evaluate actual altitude through the repetitive detections of single photons of the reflected laser pulses. We propose the single photon altimeter signal processing and data mining algorithm based on the Poisson statistic filter (histogram method) and the modified Kalman filter, providing all common altimetry products (altitude, slope, background photon flux and albedo). The Kalman filter is extended for the background noise filtering, the varying slope adaptation and the non-causal extension for an abrupt slope change. Moreover, the algorithm partially removes the major drawback of a single photon altitude reading, namely that the photon detection measurement statistics must be gathered. The developed algorithm deduces the actual altitude on the basis of a single photon detection; thus, being optimal in the sense that each detected signal photon carrying altitude information is tracked and no altitude information is lost. The algorithm was tested on the simulated datasets and partially cross-probed with the experimental data collected using the developed single photon altimeter breadboard based on the microchip laser with the pulse energy on the order of microjoule and the repetition rate of several kilohertz. We demonstrated that such an altimeter configuration may be utilized for landing or hovering a small body (asteroid, comet).

  13. Fluorescence Resonance Energy Transfer Analysis of Recombination Signal Sequence Configuration in the RAG1/2 Synaptic Complex▿ †

    PubMed Central

    Ciubotaru, Mihai; Kriatchko, Aleksei N.; Swanson, Patrick C.; Bright, Frank V.; Schatz, David G.

    2007-01-01

    A critical step in V(D)J recombination is the synapsis of complementary (12/23) recombination signal sequences (RSSs) by the RAG1 and RAG2 proteins to generate the paired complex (PC). Using a facilitated ligation assay and substrates that vary the helical phasing of the RSSs, we provide evidence that one particular geometric configuration of the RSSs is favored in the PC. To investigate this configuration further, we used fluorescent resonance energy transfer (FRET) to detect the synapsis of fluorescently labeled RSS oligonucleotides. FRET requires an appropriate 12/23 RSS pair, a divalent metal ion, and high-mobility-group protein HMGB1 or HMGB2. Energy transfer between the RSSs was detected with all 12/23 RSS end positions of the fluorescent probes but was not detected when probes were placed on the two ends of the same RSS. Energy transfer was confirmed to originate from the PC by using an in-gel FRET assay. The results argue against a unique planar configuration of the RSSs in the PC and are most easily accommodated by models in which synapsed 12- and 23-RSSs are bent and cross one another, with implications for the organization of the RAG proteins and the DNA substrates at the time of cleavage. PMID:17470556

  14. Fluorescence resonance energy transfer analysis of recombination signal sequence configuration in the RAG1/2 synaptic complex.

    PubMed

    Ciubotaru, Mihai; Kriatchko, Aleksei N; Swanson, Patrick C; Bright, Frank V; Schatz, David G

    2007-07-01

    A critical step in V(D)J recombination is the synapsis of complementary (12/23) recombination signal sequences (RSSs) by the RAG1 and RAG2 proteins to generate the paired complex (PC). Using a facilitated ligation assay and substrates that vary the helical phasing of the RSSs, we provide evidence that one particular geometric configuration of the RSSs is favored in the PC. To investigate this configuration further, we used fluorescent resonance energy transfer (FRET) to detect the synapsis of fluorescently labeled RSS oligonucleotides. FRET requires an appropriate 12/23 RSS pair, a divalent metal ion, and high-mobility-group protein HMGB1 or HMGB2. Energy transfer between the RSSs was detected with all 12/23 RSS end positions of the fluorescent probes but was not detected when probes were placed on the two ends of the same RSS. Energy transfer was confirmed to originate from the PC by using an in-gel FRET assay. The results argue against a unique planar configuration of the RSSs in the PC and are most easily accommodated by models in which synapsed 12- and 23-RSSs are bent and cross one another, with implications for the organization of the RAG proteins and the DNA substrates at the time of cleavage.

  15. Finite-element analysis and in vitro experiments of placement configurations using triple antennas in microwave hepatic ablation.

    PubMed

    Phasukkit, Pattarapong; Tungjitkusolmun, Supan; Sangworasil, Manas

    2009-11-01

    This study presents analyses of triple-antenna configurations and designs for microwave (MW) hepatic ablation using 3-D finite-element (FE) analyses verified by in vitro experiments. Treatment of hepatic cancer often requires removal or destruction of large volume lesions. Using multiple antennas offers a potential solution for creating ablation zones with larger dimensions, as well as varied geometrical shapes. We performed both 3-D FE analyses and in vitro experiments using three identical open-tip MW antennas simultaneously, placing them in three types of configurations-"linear array," "triangular," and "T-shaped" arrangements. We compared coagulation volumes created, as well as temperature distribution characteristics, from the three-antenna arrangements after power delivery of 50 W for 60 s. We also performed additional tests using nonidentical antennas (open tip, slot, and slot with insulating jacket) for the three configurations. The results illustrate that arranging antennas in the "T-shaped" pattern destroyed more unwanted tissues than those found when using "linear array" and "triangular" arrangements, with maximum coagulation width and depth of 46 and 81 mm, respectively, and coagulation volume of 30.7 cm(3) . In addition, using nonidentical triple antennas caused variations in coagulation zone characteristics, and thus, the technique could be applied to treatment situations where nonsymmetric coagulation zones are required.

  16. Experimental analysis of large belief networks for medical diagnosis.

    PubMed Central

    Pradhan, M.; Provan, G.; Henrion, M.

    1994-01-01

    We present an experimental analysis of two parameters that are important in knowledge engineering for large belief networks. We conducted the experiments on a network derived from the Internist-1 medical knowledge base. In this network, a generalization of the noisy-OR gate is used to model causal independence for the multivalued variables, and leak probabilities are used to represent the nonspecified causes of intermediate states and findings. We study two network parameters, (1) the parameter governing the assignment of probability values to the network, and (2) the parameter denoting whether the network nodes represent variables with two or more than two values. The experimental results demonstrate that the binary simplification computes diagnoses with similar accuracy to the full multivalued network. We discuss the implications of these parameters, as well other network parameters, for knowledge engineering for medical applications. PMID:7950030

  17. Ethological and experimental approaches to behavior analysis: implications for ecotoxicology.

    PubMed Central

    Cohn, J; MacPhail, R C

    1996-01-01

    Laboratory research in toxicology has progressed far beyond reliance on measures of mortality to make use of sophisticated behavioral preparations that can evaluate the consequences of sublethal toxicant exposure. In contrast, field studies have not evolved as rapidly. Approaches developed by experimental psychologists and ethologists provide powerful and complementary methodologies to the study of environmental pollutants and behavior. Observational data collection techniques can easily be used to broaden the number of questions addressed regarding sublethal exposure to toxic agents in both field and laboratory environments. This paper provides a background in such techniques, including construction of ethograms and observational methodologies, and the use of laboratory analogues to naturally occurring activities such as social behavior, predation, and foraging. Combining ethological and experimental approaches in behavior analysis can result in a more comprehensive evaluation of the effects of environmental contaminants on behavior. PMID:9182036

  18. Numerical and experimental analysis of a retrievable offshore loading facility

    SciTech Connect

    Sterndorff, M.J.; O`Brien, P.

    1995-12-31

    ROLF (Retrievable Offshore Loading Facility) has been proposed as an alternative offshore oil export tanker loading system for the North Sea. The system consists of a flexible riser ascending from the seabed in a lazy wave configuration to the bow of a dynamically positioned tanker. In order to supplant and support the numerical analyses performed to design the system, an extensive model test program was carried out in a 3D offshore basin at scale 1:50. A model riser with properties equivalent to the properties of the oil filled prototype riser installed in seawater was tested in several combinations of waves and current. During the tests the forces at the bow of the tanker and at the pipeline end manifold were measured together with the motions of the tanker and the riser. The riser motions were measured by means of a video based 3D motion monitoring system. Of special importance was accurate determination of the minimum bending radius for the riser. This was derived based on the measured riser motions. The results of the model tests were compared to numerical analyses by an MCS proprietary riser analysis program.

  19. Elementary polarization properties in the backscattering configuration.

    PubMed

    Arteaga, Oriol; Garcia-Caurel, Enric; Ossikovski, Razvigor

    2014-10-15

    In the normal incidence backscattering configuration, a polarimetric measurement always preserves the reciprocal symmetry. For a reciprocal Jones matrix, the number of elementary polarization properties is reduced from six to four. In this work, the physical interpretation of these properties is examined and they are compared with the equivalent polarization properties in transmission. It is found that, with the exception of natural optical activity, a polarimetric backreflection experiment can essentially provide the same type of information about the anisotropy of a medium as a transmission analysis, although transmission and backreflection information comes in a completely different form. Experimental examples are provided to illustrate the discussion.

  20. Experimental and Numerical Analysis of Notched Composites Under Tension Loading

    NASA Astrophysics Data System (ADS)

    Aidi, Bilel; Case, Scott W.

    2015-12-01

    Experimental quasi-static tests were performed on center notched carbon fiber reinforced polymer (CFRP) composites having different stacking sequences made of G40-600/5245C prepreg. The three-dimensional Digital Image Correlation (DIC) technique was used during quasi-static tests conducted on quasi-isotropic notched samples to obtain the distribution of strains as a function of applied stress. A finite element model was built within Abaqus to predict the notched strength and the strain profiles for comparison with measured results. A user-material subroutine using the multi-continuum theory (MCT) as a failure initiation criterion and an energy-based damage evolution law as implemented by Autodesk Simulation Composite Analysis (ASCA) was used to conduct a quantitative comparison of strain components predicted by the analysis and obtained in the experiments. Good agreement between experimental data and numerical analyses results are observed. Modal analysis was carried out to investigate the effect of static damage on the dominant frequencies of the notched structure using the resulted degraded material elements. The first in-plane mode was found to be a good candidate for tracking the level of damage.