Direction and Integration of Experimental Ground Test Capabilities and Computational Methods

NASA Technical Reports Server (NTRS)

Dunn, Steven C.

2016-01-01

This paper groups and summarizes the salient points and findings from two AIAA conference panels targeted at defining the direction, with associated key issues and recommendations, for the integration of experimental ground testing and computational methods. Each panel session utilized rapporteurs to capture comments from both the panel members and the audience. Additionally, a virtual panel of several experts were consulted between the two sessions and their comments were also captured. The information is organized into three time-based groupings, as well as by subject area. These panel sessions were designed to provide guidance to both researchers/developers and experimental/computational service providers in defining the future of ground testing, which will be inextricably integrated with the advancement of computational tools.

Virtual Diagnostic Interface: Aerospace Experimentation in the Synthetic Environment

NASA Technical Reports Server (NTRS)

Schwartz, Richard J.; McCrea, Andrew C.

2009-01-01

The Virtual Diagnostics Interface (ViDI) methodology combines two-dimensional image processing and three-dimensional computer modeling to provide comprehensive in-situ visualizations commonly utilized for in-depth planning of wind tunnel and flight testing, real time data visualization of experimental data, and unique merging of experimental and computational data sets in both real-time and post-test analysis. The preparation of such visualizations encompasses the realm of interactive three-dimensional environments, traditional and state of the art image processing techniques, database management and development of toolsets with user friendly graphical user interfaces. ViDI has been under development at the NASA Langley Research Center for over 15 years, and has a long track record of providing unique and insightful solutions to a wide variety of experimental testing techniques and validation of computational simulations. This report will address the various aspects of ViDI and how it has been applied to test programs as varied as NASCAR race car testing in NASA wind tunnels to real-time operations concerning Space Shuttle aerodynamic flight testing. In addition, future trends and applications will be outlined in the paper.

Virtual Diagnostic Interface: Aerospace Experimentation in the Synthetic Environment

NASA Technical Reports Server (NTRS)

Schwartz, Richard J.; McCrea, Andrew C.

2010-01-01

The Virtual Diagnostics Interface (ViDI) methodology combines two-dimensional image processing and three-dimensional computer modeling to provide comprehensive in-situ visualizations commonly utilized for in-depth planning of wind tunnel and flight testing, real time data visualization of experimental data, and unique merging of experimental and computational data sets in both real-time and post-test analysis. The preparation of such visualizations encompasses the realm of interactive three-dimensional environments, traditional and state of the art image processing techniques, database management and development of toolsets with user friendly graphical user interfaces. ViDI has been under development at the NASA Langley Research Center for over 15 years, and has a long track record of providing unique and insightful solutions to a wide variety of experimental testing techniques and validation of computational simulations. This report will address the various aspects of ViDI and how it has been applied to test programs as varied as NASCAR race car testing in NASA wind tunnels to real-time operations concerning Space Shuttle aerodynamic flight testing. In addition, future trends and applications will be outlined in the paper.

Reliability of temporal summation and diffuse noxious inhibitory control

PubMed Central

Cathcart, Stuart; Winefield, Anthony H; Rolan, Paul; Lushington, Kurt

2009-01-01

BACKGROUND: The test-retest reliability of temporal summation (TS) and diffuse noxious inhibitory control (DNIC) has not been reported to date. Establishing such reliability would support the possibility of future experimental studies examining factors affecting TS and DNIC. Similarly, the use of manual algometry to induce TS, or an occlusion cuff to induce DNIC of TS to mechanical stimuli, has not been reported to date. Such devices may offer a simpler method than current techniques for inducing TS and DNIC, affording assessment at more anatomical locations and in more varied research settings. METHOD: The present study assessed the test-retest reliability of TS and DNIC using the above techniques. Sex differences on these measures were also investigated. RESULTS: Repeated measures ANOVA indicated successful induction of TS and DNIC, with no significant differences across test-retest occasions. Sex effects were not significant for any measure or interaction. Intraclass correlations indicated high test-retest reliability for all measures; however, there was large interindividual variation between test and retest measurements. CONCLUSION: The present results indicate acceptable within-session test-retest reliability of TS and DNIC. The results support the possibility of future experimental studies examining factors affecting TS and DNIC. PMID:20011713

Chemistry Notes.

ERIC Educational Resources Information Center

School Science Review, 1983

1983-01-01

Presents background information, laboratory procedures, classroom materials/activities, and chemistry experiments. Topics include sublimation, electronegativity, electrolysis, experimental aspects of strontianite, halide test, evaluation of present and future computer programs in chemistry, formula building, care of glass/saturated calomel…

Quiet Clean Short-haul Experimental Engine (QCSEE) Over The Wing (OTW) design report

NASA Technical Reports Server (NTRS)

1977-01-01

The design, fabrication, and testing of two experimental high bypass geared turbofan engines and propulsion systems for short haul passenger aircraft are described. The propulsion technology required for future externally blown flap aircraft with engines located both under the wing and over the wing is demonstrated. Composite structures and digital engine controls are among the topics included.

Japanese propagation experiments with ETS-5

NASA Technical Reports Server (NTRS)

Ikegami, Tetsushi

1989-01-01

Propagation experiments for maritime, aeronautical, and land mobile satellite communications were performed using Engineering Test Satellite-Five (ETS-5). The propagation experiments are one of major mission of Experimental Mobile Satellite System (EMSS) which is aimed for establishing basic technology for future general mobile satellite communication systems. A brief introduction is presented for the experimental results on propagation problems of ETS-5/EMSS.

Time perspective and attitude-behaviour consistency in future-oriented behaviours.

PubMed

Rabinovich, Anna; Morton, Thomas; Postmes, Tom

2010-03-01

The authors propose that the salience of a distant-future time perspective, compared to a near-future time perspective, should increase attitude-behaviour and attitude-intention consistency for future-oriented behaviours. To test this prediction, time perspective was experimentally manipulated in three studies. Across studies, participants in the distant-future time perspective condition demonstrated a strong positive relationship between attitudes towards future-oriented behaviours (saving and environmental protection) and corresponding intentions, as well as between attitudes and behaviour. In the near-future time perspective condition, the relationship between attitudes and intentions and attitudes and behaviour was significantly weaker than in the distant-future time perspective condition. The theoretical implications of these results and suggestions for future research are discussed.

Experimental investigation of hypersonic aerodynamics

NASA Technical Reports Server (NTRS)

Heinemann, K.; Intrieri, Peter F.

1987-01-01

An extensive series of ballistic range tests are currently being conducted at the Ames Research Center. These tests are intended to investigate the hypersonic aerodynamic characteristics of two basic configurations, which are: the blunt-cone Galileo probe which is scheduled to be launched in late 1989 and will enter the atmosphere of Jupiter in 1994, and a generic slender cone configuration to provide experimental aerodynamic data including good flow-field definition which computational aerodynamicists could use to validate their computer codes. Some of the results obtained thus far are presented and work for the near future is discussed.

Corrosion Assessment of Steel Bars Used in Reinforced Concrete Structures by Means of Eddy Current Testing

PubMed Central

de Alcantara, Naasson P.; da Silva, Felipe M.; Guimarães, Mateus T.; Pereira, Matheus D.

2015-01-01

This paper presents a theoretical and experimental study on the use of Eddy Current Testing (ECT) to evaluate corrosion processes in steel bars used in reinforced concrete structures. The paper presents the mathematical basis of the ECT sensor built by the authors; followed by a finite element analysis. The results obtained in the simulations are compared with those obtained in experimental tests performed by the authors. Effective resistances and inductances; voltage drops and phase angles of wound coil are calculated using both; simulated and experimental data; and demonstrate a strong correlation. The production of samples of corroded steel bars; by using an impressed current technique is also presented. The authors performed experimental tests in the laboratory using handmade sensors; and the corroded samples. In the tests four gauges; with five levels of loss-of-mass references for each one were used. The results are analyzed in the light of the loss-of-mass and show a strong linear behavior for the analyzed parameters. The conclusions emphasize the feasibility of the proposed technique and highlight opportunities for future works. PMID:26712754

Corrosion Assessment of Steel Bars Used in Reinforced Concrete Structures by Means of Eddy Current Testing.

PubMed

de Alcantara, Naasson P; da Silva, Felipe M; Guimarães, Mateus T; Pereira, Matheus D

2015-12-24

This paper presents a theoretical and experimental study on the use of Eddy Current Testing (ECT) to evaluate corrosion processes in steel bars used in reinforced concrete structures. The paper presents the mathematical basis of the ECT sensor built by the authors; followed by a finite element analysis. The results obtained in the simulations are compared with those obtained in experimental tests performed by the authors. Effective resistances and inductances; voltage drops and phase angles of wound coil are calculated using both; simulated and experimental data; and demonstrate a strong correlation. The production of samples of corroded steel bars; by using an impressed current technique is also presented. The authors performed experimental tests in the laboratory using handmade sensors; and the corroded samples. In the tests four gauges; with five levels of loss-of-mass references for each one were used. The results are analyzed in the light of the loss-of-mass and show a strong linear behavior for the analyzed parameters. The conclusions emphasize the feasibility of the proposed technique and highlight opportunities for future works.

Icing Test Results on an Advanced Two-Dimensional High-Lift Multi-Element Airfoil

NASA Technical Reports Server (NTRS)

Shin, Jaiwon; Wilcox, Peter; Chin, Vincent; Sheldon, David

1994-01-01

An experimental study has been conducted to investigate ice accretions on a high-lift, multi-element airfoil in the Icing Research Tunnel at the NASA Lewis Research Center. The airfoil is representative of an advanced transport wing design. The experimental work was conducted as part of a cooperative program between McDonnell Douglas Aerospace and the NASA Lewis Research Center to improve current understanding of ice accretion characteristics on the multi-element airfoil. The experimental effort also provided ice shapes for future aerodynamic tests at flight Reynolds numbers to ascertain high-lift performance effects. Ice shapes documented for a landing configuration over a variety of icing conditions are presented along with analyses.

THAI Multi-Compartment Containment Test Program

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

Kanzleiter, T.; Poss, G.; Funke, F.

2006-07-01

The THAI experimental programme includes combined-effect investigations on thermal hydraulics, hydrogen, and fission product (iodine and aerosols) behaviour in LWR containments under severe accident conditions. An overview on the experiments performed up to now and on the future test program is presented, in combination with a selection of typical results to illustrate the versatility of the test facility and the broad variety of topics investigated. (authors)

Heavy neutrino mixing and single production at linear collider

NASA Astrophysics Data System (ADS)

Gluza, J.; Maalampi, J.; Raidal, M.; Zrałek, M.

1997-02-01

We study the single production of heavy neutrinos via the processes e- e+ -> νN and e- γ -> W- N at future linear colliders. As a base of our considerations we take a wide class of models, both with vanishing and non-vanishing left-handed Majorana neutrino mass matrix mL. We perform a model independent analyses of the existing experimental data and find connections between the characteristic of heavy neutrinos (masses, mixings, CP eigenvalues) and the mL parameters. We show that with the present experimental constraints heavy neutrino masses almost up to the collision energy can be tested in the future experiments.

Experimental constraints on metric and non-metric theories of gravity

NASA Technical Reports Server (NTRS)

Will, Clifford M.

1989-01-01

Experimental constraints on metric and non-metric theories of gravitation are reviewed. Tests of the Einstein Equivalence Principle indicate that only metric theories of gravity are likely to be viable. Solar system experiments constrain the parameters of the weak field, post-Newtonian limit to be close to the values predicted by general relativity. Future space experiments will provide further constraints on post-Newtonian gravity.

Engine-Scale Combustor Rig Designed, Fabricated, and Tested for Combustion Instability Control Research

NASA Technical Reports Server (NTRS)

DeLaat, John C.; Breisacher, Kevin J.

2000-01-01

Low-emission combustor designs are prone to combustor instabilities. Because active control of these instabilities may allow future combustors to meet both stringent emissions and performance requirements, an experimental combustor rig was developed for investigating methods of actively suppressing combustion instabilities. The experimental rig has features similar to a real engine combustor and exhibits instabilities representative of those in aircraft gas turbine engines. Experimental testing in the spring of 1999 demonstrated that the rig can be tuned to closely represent an instability observed in engine tests. Future plans are to develop and demonstrate combustion instability control using this experimental combustor rig. The NASA Glenn Research Center at Lewis Field is leading the Combustion Instability Control program to investigate methods for actively suppressing combustion instabilities. Under this program, a single-nozzle, liquid-fueled research combustor rig was designed, fabricated, and tested. The rig has many of the complexities of a real engine combustor, including an actual fuel nozzle and swirler, dilution cooling, and an effusion-cooled liner. Prior to designing the experimental rig, a survey of aircraft engine combustion instability experience identified an instability observed in a prototype engine as a suitable candidate for replication. The frequency of the instability was 525 Hz, with an amplitude of approximately 1.5-psi peak-to-peak at a burner pressure of 200 psia. The single-nozzle experimental combustor rig was designed to preserve subcomponent lengths, cross sectional area distribution, flow distribution, pressure-drop distribution, temperature distribution, and other factors previously found to be determinants of burner acoustic frequencies, mode shapes, gain, and damping. Analytical models were used to predict the acoustic resonances of both the engine combustor and proposed experiment. The analysis confirmed that the test rig configuration and engine configuration had similar longitudinal acoustic characteristics, increasing the likelihood that the engine instability would be replicated in the rig. Parametric analytical studies were performed to understand the influence of geometry and condition variations and to establish a combustion test plan. Cold-flow experiments verified that the design values of area and flow distributions were obtained. Combustion test results established the existence of a longitudinal combustion instability in the 500-Hz range with a measured amplitude approximating that observed in the engine. Modifications to the rig configuration during testing also showed the potential for injector independence. The research combustor rig was developed in partnership with Pratt & Whitney of West Palm Beach, Florida, and United Technologies Research Center of East Hartford, Connecticut. Experimental testing of the combustor rig took place at United Technologies Research Center.

Structural Dynamics Experimental Activities in Ultra-Lightweight and Inflatable Space Structures

NASA Technical Reports Server (NTRS)

Pappa, Richard S.; Lassiter, John O.; Ross, Brian P.

2001-01-01

This paper reports recently completed structural dynamics experimental activities with new ultralightweight and inflatable space structures (a.k.a., "Gossamer" spacecraft) at NASA Langley Research Center, NASA Marshall Space Flight Center, and NASA Goddard Space Flight Center. Nine aspects of this work are covered, as follows: 1) inflated, rigidized tubes, 2) active control experiments, 3) photogrammetry, 4) laser vibrometry, 5) modal tests of inflatable structures, 6) in-vacuum modal tests, 7) tensioned membranes, 8) deployment tests, and 9) flight experiment support. Structural dynamics will play a major role in the design and eventual in-space deployment and performance of Gossamer spacecraft, and experimental R&D work such as this is required now to validate new analytical prediction methods. The activities discussed in the paper are pathfinder accomplishments, conducted on unique components and prototypes of future spacecraft systems.

A far-field radio-frequency experimental exposure system with unrestrained mice.

PubMed

Hansen, Jared W; Asif, Sajid; Singelmann, Lauren; Khan, Muhammad Saeed; Ghosh, Sumit; Gustad, Tom; Doetkott, Curt; Braaten, Benjamin D; Ewert, Daniel L

2015-01-01

Many studies have been performed on exploring the effects of radio-frequency (RF) energy on biological function in vivo. In particular, gene expression results have been inconclusive due, in part, to a lack of a standardized experimental procedure. This research describes a new far field RF exposure system for unrestrained murine models that reduces experimental error. The experimental procedure includes the materials used, the creation of a patch antenna, the uncertainty analysis of the equipment, characterization of the test room, experimental equipment used and setup, power density and specific absorption rate experiment, and discussion. The result of this research is an experimental exposure system to be applied to future biological studies.

Preschool life skills: Recent advancements and future directions.

PubMed

Fahmie, Tara A; Luczynski, Kevin C

2018-01-01

Over the past decade, researchers have replicated and extended research on the preschool life skills (PLS) program developed by Hanley, Heal, Tiger, and Ingvarsson (2007). This review summarizes recent research with respect to maximizing skill acquisition, improving generality, evaluating feasibility and acceptability, and testing predictions of the initial PLS study. For each area, we suggest directions for future research. © 2018 Society for the Experimental Analysis of Behavior.

Future X Pathfinder: Quick, Low Cost Flight Testing for Tomorrow's Launch Vehicles

NASA Technical Reports Server (NTRS)

London, John, III; Sumrall, Phil

1999-01-01

The DC-X and DC-XA Single Stage Technology flight program demonstrated the value of low cost rapid prototyping and flight testing of launch vehicle technology testbeds. NASA is continuing this important legacy through a program referred to as Future-X Pathfinder. This program is designed to field flight vehicle projects that cost around $100M each, with a new vehicle flying about every two years. Each vehicle project will develop and extensively flight test a launch vehicle technology testbed that will advance the state of the art in technologies directly relevant to future space transportation systems. There are currently two experimental, or "X" vehicle projects in the Pathfinder program, with additional projects expected to follow in the near future. The first Pathfinder project is X-34. X-34 is a suborbital rocket plane capable of flights to Mach 8 and 75 kilometers altitude. There are a number of reusable launch vehicle technologies embedded in the X-34 vehicle design, such as composite structures and propellant tanks, and advanced reusable thermal protection systems. In addition, X-34 is designed to carry experiments applicable to both the launch vehicle and hypersonic aeronautics community. X-34 is scheduled to fly later this year. The second Pathfinder project is the X-37. X-37 is an orbital space plane that is carried into orbit either by the Space Shuttle or by an expendable launch vehicle. X-37 provides NASA access to the orbital and orbital reentry flight regimes with an experimental testbed vehicle. The vehicle will expose embedded and carry-on advanced space transportation technologies to the extreme environments of orbit and reentry. Early atmospheric approach and landing tests of an unpowered version of the X-37 will begin next year, with orbital flights beginning in late 2001. Future-X Pathfinder is charting a course for the future with its growing fleet of low-cost X- vehicles. X-34 and X-37 are leading the assault on high launch costs and enabling the flight testing of technologies that will lead to affordable access to space.

Development and Experimental Application of International Affairs Indicators. Volume A

DTIC Science & Technology

1974-06-01

DEVELOPMENT ’^EXPERIMENTAL APPttcATION OF INTERNATIONAL AFFAIRS INDICATORS Volume A Final Report e June 1974 US I Sponsored by: Defense Advanced...intelligence communities were designed, techniques for estimating the future were developed and tested, and the techniques and indicators were applied to the...past year’s effort is that the intelligence community has become increasingly aware of the potential use- fulness of quantitative indicators. The

[Research progress on mechanical performance evaluation of artificial intervertebral disc].

PubMed

Li, Rui; Wang, Song; Liao, Zhenhua; Liu, Weiqiang

2018-03-01

The mechanical properties of artificial intervertebral disc (AID) are related to long-term reliability of prosthesis. There are three testing methods involved in the mechanical performance evaluation of AID based on different tools: the testing method using mechanical simulator, in vitro specimen testing method and finite element analysis method. In this study, the testing standard, testing equipment and materials of AID were firstly introduced. Then, the present status of AID static mechanical properties test (static axial compression, static axial compression-shear), dynamic mechanical properties test (dynamic axial compression, dynamic axial compression-shear), creep and stress relaxation test, device pushout test, core pushout test, subsidence test, etc. were focused on. The experimental techniques using in vitro specimen testing method and testing results of available artificial discs were summarized. The experimental methods and research status of finite element analysis were also summarized. Finally, the research trends of AID mechanical performance evaluation were forecasted. The simulator, load, dynamic cycle, motion mode, specimen and test standard would be important research fields in the future.

Entry, Descent, and Landing With Propulsive Deceleration: Supersonic Retropropulsion Wind Tunnel Testing

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan

2012-01-01

The future exploration of the Solar System will require innovations in transportation and the use of entry, descent, and landing (EDL) systems at many planetary landing sites. The cost of space missions has always been prohibitive, and using the natural planetary and planet s moons atmosphere for entry, descent, and landing can reduce the cost, mass, and complexity of these missions. This paper will describe some of the EDL ideas for planetary entry and survey the overall technologies for EDL that may be attractive for future Solar System missions. Future EDL systems may include an inflatable decelerator for the initial atmospheric entry and an additional supersonic retro-propulsion (SRP) rocket system for the final soft landing. As part of those efforts, NASA began to conduct experiments to gather the experimental data to make informed decisions on the "best" EDL options. A model of a three engine retro-propulsion configuration with a 2.5 in. diameter sphere-cone aeroshell model was tested in the NASA Glenn 1- by 1-Foot Supersonic Wind Tunnel (SWT). The testing was conducted to identify potential blockage issues in the tunnel, and visualize the rocket flow and shock interactions during supersonic and hypersonic entry conditions. Earlier experimental testing of a 70 Viking-like (sphere-cone) aeroshell was conducted as a baseline for testing of a supersonic retro-propulsion system. This baseline testing defined the flow field around the aeroshell and from this comparative baseline data, retro-propulsion options will be assessed. Images and analyses from the SWT testing with 300- and 500-psia rocket engine chamber pressures are presented here. The rocket engine flow was simulated with a non-combusting flow of air.

CMC thermal protection system for future reusable launch vehicles: Generic shingle technological maturation and tests

NASA Astrophysics Data System (ADS)

Pichon, T.; Barreteau, R.; Soyris, P.; Foucault, A.; Parenteau, J. M.; Prel, Y.; Guedron, S.

2009-07-01

Experimental re-entry demonstrators are currently being developed in Europe, with the objective of increasing the technology readiness level (TRL) of technologies applicable to future reusable launch vehicles. Among these are the Pre-X programme, currently funded by CNES, the French Space Agency, and which is about to enter into development phase B, and the IXV, within the future launcher preparatory programme (FLPP) funded by ESA. One of the major technologies necessary for such vehicles is the thermal protection system (TPS), and in particular the ceramic matrix composites (CMC) based windward TPS. In support of this goal, technology maturation activities named "generic shingle" were initiated beginning of 2003 by SPS, under a CNES contract, with the objective of performing a test campaign of a complete shingle of generic design, in preparation of the development of a re-entry experimental vehicle decided in Europe. The activities performed to date include: the design, manufacturing of two C/SiC panels, finite element model (FEM) calculation of the design, testing of technological samples extracted from a dedicated panel, mechanical pressure testing of a panel, and a complete study of the attachment system. Additional testing is currently under preparation on the panel equipped with its insulation, seal, attachment device, and representative portion of cold structure, to further assess its behaviour in environments relevant to its application The paper will present the activities that will have been performed in 2006 on the prediction and preparation of these modal characterization, dynamic, acoustic as well as thermal and thermo-mechanical tests. Results of these tests will be presented and the lessons learned will be discussed.

SuperCDMS Underground Detector Fabrication Facility

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

Platt, M.; Mahapatra, R.; Bunker, Raymond A.

The SuperCDMS SNOLAB dark matter experiment processes Ge and Si crystals into fully tested phonon and ionization detectors at surface fabrication and test facilities. If not mitigated, it is anticipated that trace-level production of radioisotopes in the crystals due to exposure to cosmic rays at (or above) sea level will result in the dominant source of background events in future dark matter searches using the current SuperCDMS detector technology. Fabrication and testing of detectors in underground facilities shielded from cosmic radiation is one way to directly reduce production of trace levels of radioisotopes, thereby improving experimental sensitivity for the discoverymore » of dark matter beyond the level of the current experiment. In this report, we investigate the cost and feasibility to establish a complete detector fabrication processing chain in an underground location to mitigate cosmogenic activation of the Ge and Si detector substrates. For a specific and concrete evaluation, we explore options for such a facility located at SNOLAB, an underground laboratory in Sudbury, Canada hosting the current and future experimental phases of SuperCDMS.« less

Structural Qualification of Composite Airframes

NASA Technical Reports Server (NTRS)

Kedward, Keith T.; McCarty, John E.

1997-01-01

The development of fundamental approaches for predicting failure and elongation characteristics of fibrous composites are summarized in this document. The research described includes a statistical formulation for individual fiber breakage and fragmentation and clustered fiber breakage, termed macrodefects wherein the aligned composite may represent a structural component such as a reinforcing bar element, a rebar. Experimental work conducted in support of the future exploitation of aligned composite rebar elements is also described. This work discusses the experimental challenges associated with rebar tensile test evaluation and describes initial numerical analyses performed in support of the experimental program.

Experimentation and evaluation of advanced integrated system concepts

NASA Astrophysics Data System (ADS)

Ross, M.; Garrigus, K.; Gottschalck, J.; Rinearson, L.; Longee, E.

1980-09-01

This final report examines the implementation of a time-phased test bed for experimentation and evaluation of advanced system concepts relative to the future Defense Switched Network (DSN). After identifying issues pertinent to the DSN, a set of experiments which address these issues are developed. Experiments are ordered based on their immediacy and relative importance to DSN development. The set of experiments thus defined allows requirements for a time phased implementation of a test bed to be identified, and several generic test bed architectures which meet these requirements are examined. Specific architecture implementations are costed and cost/schedule profiles are generated as a function of experimental capability. The final recommended system consists of two separate test beds: a circuit switch test bed, configured around an off-the-shelf commercial switch, and directed toward the examination of nearer term and transitional issues raised by the evolving DSN; and a packet/hybrid test bed, featuring a discrete buildup of new hardware and software modules, and directed toward examination of the more advanced integrated voice and data telecommunications issues and concepts.

Antecedents and Consequences of Supplier Performance Evaluation Efficacy

DTIC Science & Technology

2016-06-30

forming groups of high and low values. These tests are contingent on the reliable and valid measure of high and low rating inflation and high and...year)? Future research could deploy a SPM system as a test case on a limited set of transactions. Using a quasi-experimental design , comparisons...single source, common method bias must be of concern. Harmon’s one -factor test showed that when latent-indicator items were forced onto a single

Off-Road Soft Soil Tire Model Development and Experimental Testing

DTIC Science & Technology

2011-06-29

Eduardo Pinto 2 , Mr. Scott Naranjo 3 , Dr. Paramsothy Jayakumar 4 , Dr. Archie Andonian 5 , Dr. Dave Hubbell 6 , Dr. Brant Ross 7 1Virginia...The effect of soil charac- teristics on the tire dynamics will be studied. Validation against data collected from full vehicle testing is included in...the proposed future work. Keywords: tire model, soft soil, terramechanics, vehicle dynamics , indoor testing 1 Introduction The goal of this paper is

Shuttle free-flying teleoperator system experiment definition. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

1972-01-01

The applicability and utility of a free-flying teleoperator system were evaluated to support future earth orbital missions, specific emphasis on the early missions of the space shuttle. In-flight experiments and tests were specified, which will provide sufficient experience and data applicable to the development of future operational systems. The difinition of a useful early experimental system is presented, which will be checked out and used with early shuttle missions.

Quiet Clean Short-Haul Experimental Engine (QCSEE) Under-the-Wing (UTW) Final Design Report

NASA Technical Reports Server (NTRS)

1977-01-01

The QCSEE Program provides for the design, fabrication, and testing of two experimental high-bypass geared turbofan engines and propulsion systems for short-haul passenger aircraft. The overall objective of the program is to develop the propulsion technology required for future externally blown flap types of aircraft with engines located both under-the-wing and over-the-wing. This technology includes work in composite structures and digital engine controls.

Experimental Stage Separation Tool Development in NASA Langley's Aerothermodynamics Laboratory

NASA Technical Reports Server (NTRS)

Murphy, Kelly J.; Scallion, William I.

2005-01-01

As part of the research effort at NASA in support of the stage separation and ascent aerothermodynamics research program, proximity testing of a generic bimese wing-body configuration was conducted in NASA Langley's Aerothermodynamics Laboratory in the 20-Inch Mach 6 Air Tunnel. The objective of this work is the development of experimental tools and testing methodologies to apply to hypersonic stage separation problems for future multi-stage launch vehicle systems. Aerodynamic force and moment proximity data were generated at a nominal Mach number of 6 over a small range of angles of attack. The generic bimese configuration was tested in a belly-to-belly and back-to-belly orientation at 86 relative proximity locations. Over 800 aerodynamic proximity data points were taken to serve as a database for code validation. Longitudinal aerodynamic data generated in this test program show very good agreement with viscous computational predictions. Thus a framework has been established to study separation problems in the hypersonic regime using coordinated experimental and computational tools.

Use of an Expansion Tube to Examine Scramjet Combustion at Hypersonic Velocities

NASA Technical Reports Server (NTRS)

Rizkalla, Oussama; Bakos, Robert J.; Chinitz, Wallace; Pulsonetti, Maria V; Erdos, John I.

1989-01-01

Combustion testing at total enthalpy conditions corresponding to flight Math numbers in excess of 12 requires the use of impulse facilities. The expansion tube is the only operational facility of its size which can provide these conditions without excessive oxygen dissociation or driver gas contamination. Expansio tube operation is described herein and the operational parameters having the largest impact on its performance are determined. These are: driver-to-intermediate chamber pressure ratio, driver gas molecular weight and specific heat ratio, and driver gas temperature. Increases in the lase named parameter will markedly affect the test section static pressure. Preliminary calibration tests are discussed and test gas conditions which have been achieved are presented. Calculated and experimental test times are compared and the parameters affecting test time are discussed. The direction of future work using this important experimental tool is indicated.

Use of an expansion tube to examine scramjet combustion at hypersonic velocities

NASA Technical Reports Server (NTRS)

Rizkalla, O.; Bakos, R. J.; Pulsonetti, M.; Chinitz, Wallace; Erdos, John I.

1989-01-01

Combustion testing at total enthalpy conditions corresponding to flight Mach numbers in excess of 12 requires the use of impulse facilities. The expansion tube is the only operational facility of its size which can provide these conditions without excessive oxygen dissociation or driver gas contamination. Expansion tube operation is described herein and the operational parameters having the largest impact on its performance are determined. These are: driver-to-intermediate chamber pressure ratio, driver gas molecular weight and specific heat ratio, and driver gas temperature. Increases in the last-named parameter will markedly affect the test section static pressure. Preliminary calibration tests are discussed and test gas conditions which have been achieved are presented. Calculated and experimental test times are compared and the parameters affecting test time are discussed. The direction of future work using this important experimental tool is indicated.

Measuring and Advancing Experimental Design Ability in an Introductory Course without Altering Existing Lab Curriculum.

PubMed

Shanks, Ryan A; Robertson, Chuck L; Haygood, Christian S; Herdliksa, Anna M; Herdliska, Heather R; Lloyd, Steven A

2017-01-01

Introductory biology courses provide an important opportunity to prepare students for future courses, yet existing cookbook labs, although important in their own way, fail to provide many of the advantages of semester-long research experiences. Engaging, authentic research experiences aid biology students in meeting many learning goals. Therefore, overlaying a research experience onto the existing lab structure allows faculty to overcome barriers involving curricular change. Here we propose a working model for this overlay design in an introductory biology course and detail a means to conduct this lab with minimal increases in student and faculty workloads. Furthermore, we conducted exploratory factor analysis of the Experimental Design Ability Test (EDAT) and uncovered two latent factors which provide valid means to assess this overlay model's ability to increase advanced experimental design abilities. In a pre-test/post-test design, we demonstrate significant increases in both basic and advanced experimental design abilities in an experimental and comparison group. We measured significantly higher gains in advanced experimental design understanding in students in the experimental group. We believe this overlay model and EDAT factor analysis contribute a novel means to conduct and assess the effectiveness of authentic research experiences in an introductory course without major changes to the course curriculum and with minimal increases in faculty and student workloads.

Numerical Modeling of Active Flow Control in a Boundary Layer Ingesting Offset Inlet

NASA Technical Reports Server (NTRS)

Allan, Brian G.; Owens, Lewis R.; Berrier, Bobby L.

2004-01-01

This investigation evaluates the numerical prediction of flow distortion and pressure recovery for a boundary layer ingesting offset inlet with active flow control devices. The numerical simulations are computed using a Reynolds averaged Navier-Stokes code developed at NASA. The numerical results are validated by comparison to experimental wind tunnel tests conducted at NASA Langley Research Center at both low and high Mach numbers. Baseline comparisons showed good agreement between numerical and experimental results. Numerical simulations for the inlet with passive and active flow control also showed good agreement at low Mach numbers where experimental data has already been acquired. Numerical simulations of the inlet at high Mach numbers with flow control jets showed an improvement of the flow distortion. Studies on the location of the jet actuators, for the high Mach number case, were conducted to provide guidance for the design of a future experimental wind tunnel test.

Teaching of students technology early professional orientation of schoolchildren

NASA Astrophysics Data System (ADS)

Gilmanshina, S. I.; Sagitova, R. N.; Gilmanshin, I. R.; Kamaleeva, A. R.

2017-09-01

The necessity of early professional orientation of schoolchildren on the engineering profession and a new type of teacher was proved. Theoretically substantiated and experimentally tested pedagogical conditions of training of students - future teachers of technology early professional orientation of schoolchildren in the system of university preparation of teacher of a new type. This development of courses of special disciplines, aimed at developing of future teachers of readiness for early career guidance activities; development of interactive group projects for schoolchildren of different age groups (including primary school), expanding their understanding of the world of professions; practical testing of career guidance projects dealing with children’s audience.

An Overview of an Experimental Demonstration Aerotow Program

NASA Technical Reports Server (NTRS)

Murray, James E.; Bowers, Albion H.; Lokos, William A.; Peters, Todd L.; Gera, Joseph

1998-01-01

An overview of an experimental demonstration of aerotowing a delta-wing airplane with low-aspect ratio and relatively high wing loading is presented. Aerotowing of future space launch configurations is a new concept, and the objective of the work described herein is to demonstrate the aerotow operation using an airplane configuration similar to conceptual space launch vehicles. Background information on the use of aerotow for a space launch vehicle is presented, and the aerotow system used in this demonstration is described. The ground tests, analytical studies, and flight planning used to predict system behavior and to enhance flight safety are detailed. The instrumentation suite and flight test maneuvers flown are discussed, preliminary performance is assessed, and flight test results are compared with the preflight predictions.

Controls-structures interaction guest investigator program: Overview and phase 1 experimental results and future plans

NASA Technical Reports Server (NTRS)

Smith-Taylor, Rudeen; Tanner, Sharon E.

1993-01-01

The NASA Controls-Structures Interaction (CSI) Guest Investigator program is described in terms of its support of the development of CSI technologies. The program is based on the introduction of CSI researchers from industry and academia to available test facilities for experimental validation of technologies and methods. Phase 1 experimental results are reviewed with attention given to their use of the Mini-MAST test facility and the facility for the Advance Control Evaluation of Structures. Experiments were conducted regarding the following topics: collocated/noncollocated controllers, nonlinear math modeling, controller design, passive/active suspension systems design, and system identification and fault isolation. The results demonstrate that significantly enhanced performance from the control techniques can be achieved by integrating knowledge of the structural dynamics under consideration into the approaches.

Early warning signals detect critical impacts of experimental warming.

PubMed

Jarvis, Lauren; McCann, Kevin; Tunney, Tyler; Gellner, Gabriel; Fryxell, John M

2016-09-01

Earth's surface temperatures are projected to increase by ~1-4°C over the next century, threatening the future of global biodiversity and ecosystem stability. While this has fueled major progress in the field of physiological trait responses to warming, it is currently unclear whether routine population monitoring data can be used to predict temperature-induced population collapse. Here, we integrate trait performance theory with that of critical tipping points to test whether early warning signals can be reliably used to anticipate thermally induced extinction events. We find that a model parameterized by experimental growth rates exhibits critical slowing down in the vicinity of an experimentally tested critical threshold, suggesting that dynamical early warning signals may be useful in detecting the potentially precipitous onset of population collapse due to global climate change.

Experimental evidence for adaptive personalities in a wild passerine bird

PubMed Central

Nicolaus, Marion; Tinbergen, Joost M.; Bouwman, Karen M.; Michler, Stephanie P. M.; Ubels, Richard; Both, Christiaan; Kempenaers, Bart; Dingemanse, Niels J.

2012-01-01

Individuals of the same species differ consistently in risky actions. Such ‘animal personality’ variation is intriguing because behavioural flexibility is often assumed to be the norm. Recent theory predicts that between-individual differences in propensity to take risks should evolve if individuals differ in future fitness expectations: individuals with high long-term fitness expectations (i.e. that have much to lose) should behave consistently more cautious than individuals with lower expectations. Consequently, any manipulation of future fitness expectations should result in within-individual changes in risky behaviour in the direction predicted by this adaptive theory. We tested this prediction and confirmed experimentally that individuals indeed adjust their ‘exploration behaviour’, a proxy for risk-taking behaviour, to their future fitness expectations. We show for wild great tits (Parus major) that individuals with experimentally decreased survival probability become faster explorers (i.e. increase risk-taking behaviour) compared to individuals with increased survival probability. We also show, using quantitative genetics approaches, that non-genetic effects (i.e. permanent environment effects) underpin adaptive personality variation in this species. This study thereby confirms a key prediction of adaptive personality theory based on life-history trade-offs, and implies that selection may indeed favour the evolution of personalities in situations where individuals differ in future fitness expectations. PMID:23097506

Robust Bayesian Experimental Design for Conceptual Model Discrimination

NASA Astrophysics Data System (ADS)

Pham, H. V.; Tsai, F. T. C.

2015-12-01

A robust Bayesian optimal experimental design under uncertainty is presented to provide firm information for model discrimination, given the least number of pumping wells and observation wells. Firm information is the maximum information of a system can be guaranteed from an experimental design. The design is based on the Box-Hill expected entropy decrease (EED) before and after the experiment design and the Bayesian model averaging (BMA) framework. A max-min programming is introduced to choose the robust design that maximizes the minimal Box-Hill EED subject to that the highest expected posterior model probability satisfies a desired probability threshold. The EED is calculated by the Gauss-Hermite quadrature. The BMA method is used to predict future observations and to quantify future observation uncertainty arising from conceptual and parametric uncertainties in calculating EED. Monte Carlo approach is adopted to quantify the uncertainty in the posterior model probabilities. The optimal experimental design is tested by a synthetic 5-layer anisotropic confined aquifer. Nine conceptual groundwater models are constructed due to uncertain geological architecture and boundary condition. High-performance computing is used to enumerate all possible design solutions in order to identify the most plausible groundwater model. Results highlight the impacts of scedasticity in future observation data as well as uncertainty sources on potential pumping and observation locations.

A Study of Risk Factors in Recidivistic Criminals

PubMed Central

Tiwari, S.C.; Gupta, S. C.; Shukla, Seema; Srivastava, Shipra; Pandey, Mamta; Maurya, Amit; Kumar, Aditya

2004-01-01

A study was carried out under the aegis of Indian Council of Medical Research, New Delhi with objectives to identify psychosocial, physical, psychiatric, anthropometric and psychometric risk factors in recidivistic criminals, which could predict a future recidivistic criminal. The paper presents study observations on 250 experimental, 250 control-1 and 250 control-2 subjects. Experimental and control-1 subjects were recruited from district jails of Uttar Pradesh and control-2 from the community. Pretested Semi-structured proformae, Verghese and Beig Symptoms Checklist, International Personality Disorder Examination module, Hostility and Direction of Hostility Questionnaire, Rorschach Ink Blot Test and Standard Anthropometric instruments were used to collect data on study probands. All the three groups were compared using Analysis of Variance and Chi-Square Test. The results highlight a number of psycho-social, psychiatric, psychometric and anthropometric factors which were found to have significant association with recidivistic criminal behaviour. The findings would not only help in identifying future recidivistic criminals but can also be used for legal, judicial, interventional and corrective purposes. PMID:21408043

First experimental evidence of hydrodynamic tunneling of ultra-relativistic protons in extended solid copper target at the CERN HiRadMat facility

NASA Astrophysics Data System (ADS)

Schmidt, R.; Blanco Sancho, J.; Burkart, F.; Grenier, D.; Wollmann, D.; Tahir, N. A.; Shutov, A.; Piriz, A. R.

2014-08-01

A novel experiment has been performed at the CERN HiRadMat test facility to study the impact of the 440 GeV proton beam generated by the Super Proton Synchrotron on extended solid copper cylindrical targets. Substantial hydrodynamic tunneling of the protons in the target material has been observed that leads to significant lengthening of the projectile range, which confirms our previous theoretical predictions [N. A. Tahir et al., Phys. Rev. Spec. Top.-Accel. Beams 15, 051003 (2012)]. Simulation results show very good agreement with the experimental measurements. These results have very important implications on the machine protection design for powerful machines like the Large Hadron Collider (LHC), the future High Luminosity LHC, and the proposed huge 80 km circumference Future Circular Collider, which is currently being discussed at CERN. Another very interesting outcome of this work is that one may also study the field of High Energy Density Physics at this test facility.

V/STOL and STOL ground effects and testing techniques

NASA Technical Reports Server (NTRS)

Kuhn, R. E.

1987-01-01

The ground effects associated with V/STOL operation were examined and an effort was made to develop the equipment and testing techniques needed for that understanding. Primary emphasis was on future experimental programs in the 40 x 80 and the 80 x 120 foot test sections and in the outdoor static test stand associated with these facilities. The commonly used experimental techniques are reviewed and data obtained by various techniques are compared with each other and with available estimating methods. These reviews and comparisons provide insight into the limitations of past studies and the testing techniques used and identify areas where additional work is needed. The understanding of the flow mechanics involved in hovering and in transition in and out of ground effect is discussed. The basic flow fields associated with hovering, transition and STOL operation of jet powered V/STOL aircraft are depicted.

Assessment of Experimental Uncertainty for a Floating Wind Semisubmersible under Hydrodynamic Loading: Preprint

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

Robertson, Amy N; Wendt, Fabian F; Jonkman, Jason

The objective of this paper is to assess the sources of experimental uncertainty in an offshore wind validation campaign focused on better understanding the nonlinear hydrodynamic response behavior of a floating semisubmersible. The test specimen and conditions were simplified compared to other floating wind test campaigns to reduce potential sources of uncertainties and better focus on the hydrodynamic load attributes. Repeat tests were used to understand the repeatability of the test conditions and to assess the level of random uncertainty in the measurements. Attention was also given to understanding bias in all components of the test. The end goal ofmore » this work is to set uncertainty bounds on the response metrics of interest, which will be used in future work to evaluate the success of modeling tools in accurately calculating hydrodynamic loads and the associated motion responses of the system.« less

A processing centre for the CNES CE-GPS experimentation

NASA Technical Reports Server (NTRS)

Suard, Norbert; Durand, Jean-Claude

1994-01-01

CNES is involved in a GPS (Global Positioning System) geostationary overlay experimentation. The purpose of this experimentation is to test various new techniques in order to select the optimal station synchronization method, as well as the geostationary spacecraft orbitography method. These new techniques are needed to develop the Ranging GPS Integrity Channel services. The CNES experimentation includes three transmitting/receiving ground stations (manufactured by IN-SNEC), one INMARSAT 2 C/L band transponder and a processing center named STE (Station de Traitements de l'Experimentation). Not all the techniques to be tested are implemented, but the experimental system has to include several functions; part of the future system simulation functions, such as a servo-loop function, and in particular a data collection function providing for rapid monitoring of system operation, analysis of existing ground station processes, and several weeks of data coverage for other scientific studies. This paper discusses system architecture and some criteria used in its design, as well as the monitoring function, the approach used to develop a low-cost and short-life processing center in collaboration with a CNES sub-contractor (ATTDATAID), and some results.

Alternate methodologies to experimentally investigate shock initiation properties of explosives

NASA Astrophysics Data System (ADS)

Svingala, Forrest R.; Lee, Richard J.; Sutherland, Gerrit T.; Benjamin, Richard; Boyle, Vincent; Sickels, William; Thompson, Ronnie; Samuels, Phillip J.; Wrobel, Erik; Cornell, Rodger

2017-01-01

Reactive flow models are desired for new explosive formulations early in the development stage. Traditionally, these models are parameterized by carefully-controlled 1-D shock experiments, including gas-gun testing with embedded gauges and wedge testing with explosive plane wave lenses (PWL). These experiments are easy to interpret due to their 1-D nature, but are expensive to perform and cannot be performed at all explosive test facilities. This work investigates alternative methods to probe shock-initiation behavior of new explosives using widely-available pentolite gap test donors and simple time-of-arrival type diagnostics. These experiments can be performed at a low cost at most explosives testing facilities. This allows experimental data to parameterize reactive flow models to be collected much earlier in the development of an explosive formulation. However, the fundamentally 2-D nature of these tests may increase the modeling burden in parameterizing these models and reduce general applicability. Several variations of the so-called modified gap test were investigated and evaluated for suitability as an alternative to established 1-D gas gun and PWL techniques. At least partial agreement with 1-D test methods was observed for the explosives tested, and future work is planned to scope the applicability and limitations of these experimental techniques.

Placing Antismoking Graphic Warning Posters at Retail Point-of-Sale Locations Increases Some Adolescents' Susceptibility to Future Smoking.

PubMed

Shadel, William G; Martino, Steven C; Setodji, Claude; Dunbar, Michael; Kusuke, Daniela; Lanna, Serafina; Meyer, Amanda

2017-12-13

This experiment tested whether introducing graphic antitobacco posters at point-of-sale (POS) had any effect on adolescents' susceptibility to future cigarette smoking and whether these effects were moderated by adolescents' baseline risk of cigarette smoking. The study was conducted in the RAND StoreLab, a life-sized replica of a convenience store that was developed to experimentally evaluate how changing aspects of tobacco advertising displays in retail POS environments influence tobacco use risk and behavior during simulated shopping experiences. In this study, 441 adolescents were randomized to one of the four conditions in a 2 (graphic antismoking poster placed near the tobacco power wall: no, yes) × 2 (graphic antismoking poster placed near the cash register: no, yes) experimental design. The outcome of interest was susceptibility to future cigarette smoking. The addition of antismoking posters at POS led to a significant increase in future smoking susceptibility among those adolescents who already were at high risk for smoking in the future (p < .045). The introduction of graphic antismoking posters had no impact on committed never smokers, regardless of poster location; never smokers' susceptibility to future smoking was uniformly low across experimental conditions. Introducing graphic antismoking posters at POS may have the unintended effect of further increasing cigarette smoking susceptibility among adolescents already at risk. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

REVIEWS OF TOPICAL PROBLEMS: Experimental tests of general relativity: recent progress and future directions

NASA Astrophysics Data System (ADS)

Turyshev, S. G.

2009-01-01

Einstein's general theory of relativity is the standard theory of gravity, especially where the needs of astronomy, astrophysics, cosmology, and fundamental physics are concerned. As such, this theory is used for many practical purposes involving spacecraft navigation, geodesy, and time transfer. We review the foundations of general relativity, discuss recent progress in tests of relativistic gravity, and present motivations for the new generation of high-accuracy tests of new physics beyond general relativity. Space-based experiments in fundamental physics are presently capable of uniquely addressing important questions related to the fundamental laws of nature. We discuss the advances in our understanding of fundamental physics that are anticipated in the near future and evaluate the discovery potential of a number of recently proposed space-based gravitational experiments.

An Automated, Experimenter-Free Method for the Standardised, Operant Cognitive Testing of Rats

PubMed Central

Rivalan, Marion; Munawar, Humaira; Fuchs, Anna; Winter, York

2017-01-01

Animal models of human pathology are essential for biomedical research. However, a recurring issue in the use of animal models is the poor reproducibility of behavioural and physiological findings within and between laboratories. The most critical factor influencing this issue remains the experimenter themselves. One solution is the use of procedures devoid of human intervention. We present a novel approach to experimenter-free testing cognitive abilities in rats, by combining undisturbed group housing with automated, standardized and individual operant testing. This experimenter-free system consisted of an automated-operant system (Bussey-Saksida rat touch screen) connected to a home cage containing group living rats via an automated animal sorter (PhenoSys). The automated animal sorter, which is based on radio-frequency identification (RFID) technology, functioned as a mechanical replacement of the experimenter. Rats learnt to regularly and individually enter the operant chamber and remained there for the duration of the experimental session only. Self-motivated rats acquired the complex touch screen task of trial-unique non-matching to location (TUNL) in half the time reported for animals that were manually placed into the operant chamber. Rat performance was similar between the two groups within our laboratory, and comparable to previously published results obtained elsewhere. This reproducibility, both within and between laboratories, confirms the validity of this approach. In addition, automation reduced daily experimental time by 80%, eliminated animal handling, and reduced equipment cost. This automated, experimenter-free setup is a promising tool of great potential for testing a large variety of functions with full automation in future studies. PMID:28060883

A survey of experiments and experimental facilities for active control of flexible structures

NASA Technical Reports Server (NTRS)

Sparks, Dean W., Jr.; Horner, Garnett C.; Juang, Jer-Nan; Klose, Gerhard

1989-01-01

A brief survey of large space structure control related experiments and facilities was presented. This survey covered experiments performed before and up to 1982, and those of the present period (1982-...). Finally, the future planned experiments and facilities in support of the control-structure interaction (CSI) program were reported. It was stated that new, improved ground test facilities are needed to verify the new CSI design techniques that will allow future space structures to perform planned NASA missions.

Quiet Clean Short Haul Experimental Engine

NASA Image and Video Library

1973-02-21

Program manager Carl Ciepluch poses with a model of the Quiet Clean Short Haul Experimental Engine (QCSEE) conceived by the National Aeronautics and Space Administration (NASA) Lewis Research Center. The QCSEE engine was designed to power future short-distance transport aircraft without generating significant levels of noise or pollution and without hindering performance. The engines were designed to be utilized on aircraft operating from small airports with short runways. Lewis researchers investigated two powered-lift designs and an array of new technologies to deal with the shorter runways. Lewis contracted General Electric to design the two QCSEE engines—one with over-the-wing power-lift and one with an under-the-wing design. A scale model of the over-the-wing engine was tested in the Full Scale Tunnel at the Langley Research Center in 1975 and 1976. Lewis researchers investigated both versions in a specially-designed test stand, the Engine Noise Test Facility, on the hangar apron. The QCSEE engines met the goals set out by the NASA researchers. The aircraft industry, however, never built the short-distance transport aircraft for which the engines were intended. Different technological elements of the engine, however, were applied to some future General Electric engines.

Interaction between an elastic structure and free-surface flows: experimental versus numerical comparisons using the PFEM

NASA Astrophysics Data System (ADS)

Idelsohn, S. R.; Marti, J.; Souto-Iglesias, A.; Oñate, E.

2008-12-01

The paper aims to introduce new fluid structure interaction (FSI) tests to compare experimental results with numerical ones. The examples have been chosen for a particular case for which experimental results are not much reported. This is the case of FSI including free surface flows. The possibilities of the Particle Finite Element Method (PFEM) [1] for the simulation of free surface flows is also tested. The simulations are run using the same scale as the experiment in order to minimize errors due to scale effects. Different scenarios are simulated by changing the boundary conditions for reproducing flows with the desired characteristics. Details of the input data for all the examples studied are given. The aim is to identifying benchmark problems for FSI including free surface flows for future comparisons between different numerical approaches.

An Experimental Study of a Low-Jitter Pulsed Electromagnetic Plasma Accelerator

NASA Technical Reports Server (NTRS)

Thio, Y. C. Francis; Lee, Michael; Eskridge, Richard; Smith, James; Martin, Adam; Rodgers, Stephen L. (Technical Monitor)

2001-01-01

An experimental plasma accelerator for a variety of applications under development at the NASA Marshall Space Flight Center is described. The accelerator is a pulsed plasma thruster and has been tested experimentally and plasma jet velocities of approximately 50 kilometers per second have been obtained. The plasma jet structure has been photographed with 10 ns exposure times to reveal a stable and repeatable plasma structure. Data for velocity profile information has been obtained using light pipes embedded in the gun walls to record the plasma transit at various barrel locations. Preliminary spatially resolved spectral data and magnetic field probe data are also presented. A high speed triggering system has been developed and tested as a means of reducing the gun "jitter". This jitter has been characterized and future work for second generation "ultra-low jitter" gun development is identified.

An Antibiotic Resource Program for Students of the Health Professions.

ERIC Educational Resources Information Center

Tritz, Gerald J.

1986-01-01

Provides a description of a computer program developed to supplement instruction in testing of antibiotics on clinical isolates of microorganisms. The program is a simulation and database for interpretation of experimental data designed to enhance laboratory learning and prepare future physicians to use computerized diagnostic instrumentation and…

Improving Interpersonal Communication through Community Service

ERIC Educational Resources Information Center

Hoffman, August John; Wallach, Julie; Sanchez, Eduardo; Afkhami, Hasti

2009-01-01

The current study sought to determine if community based gardening projects would reduce perceptions of the need to use communication devices--cell phones or text messaging--and increase the likelihood of participating in future volunteer projects. Results strongly support the predictions in that the experimental group post-test mean score of the…

A Systematic Review of Strategies for Implementing Empirically Supported Mental Health Interventions

ERIC Educational Resources Information Center

Powell, Byron J.; Proctor, Enola K.; Glass, Joseph E.

2014-01-01

Objective: This systematic review examines experimental studies that test the effectiveness of strategies intended to integrate empirically supported mental health interventions into routine care settings. Our goal was to characterize the state of the literature and to provide direction for future implementation studies. Method: A literature…

Concepts in Physical Science.

ERIC Educational Resources Information Center

Puri, O. P.

Contained in this experimental test are instructional materials for a one-semester course designed to give liberal arts students an appreciation of (1) the nature of science, (2) the development of science, (3) the contributions of scientists, (4) the impact of scientific discoveries on mankind, and (5) the possible future effects of science. The…

Laboratory plasma interactions experiments: Results and implications to future space systems

NASA Technical Reports Server (NTRS)

Leung, Philip

1986-01-01

The experimental results discussed show the significance of the effects caused by spacecraft plasma interactions, in particular the generation of Electromagnetic Interference. As the experimental results show, the magnitude of the adverse effects induced by Plasma Interactions (PI) will be more significant for spacecraft of the next century. Therefore, research is needed to control possible adverse effects. Several techniques to control the selected PI effects are discussed. Tests, in the form of flight experiments, are needed to validate these proposed ideas.

Dynamic Flight Maneuvering Using Virtual Control Surfaces Generated by Trapped Vorticity

DTIC Science & Technology

2010-12-01

of a modified Dragon Eye UAV. These tests illustrated the possibility of controlled flight using open-loop flow control actuators. Future research...2 -1 0 1 2 z ( cm ) 0 1 2 3 4 5 1 2 3 4 5 Time (s)  (d eg ) Figure II-1 Step command tracking in plung: ideal reference model response...experimental results. The experimental results were obtained with the ball screws locked in position so that the wing model was only allowed to pitch

Measuring and Advancing Experimental Design Ability in an Introductory Course without Altering Existing Lab Curriculum†

PubMed Central

Shanks, Ryan A.; Robertson, Chuck L.; Haygood, Christian S.; Herdliksa, Anna M.; Herdliska, Heather R.; Lloyd, Steven A.

2017-01-01

Introductory biology courses provide an important opportunity to prepare students for future courses, yet existing cookbook labs, although important in their own way, fail to provide many of the advantages of semester-long research experiences. Engaging, authentic research experiences aid biology students in meeting many learning goals. Therefore, overlaying a research experience onto the existing lab structure allows faculty to overcome barriers involving curricular change. Here we propose a working model for this overlay design in an introductory biology course and detail a means to conduct this lab with minimal increases in student and faculty workloads. Furthermore, we conducted exploratory factor analysis of the Experimental Design Ability Test (EDAT) and uncovered two latent factors which provide valid means to assess this overlay model’s ability to increase advanced experimental design abilities. In a pre-test/post-test design, we demonstrate significant increases in both basic and advanced experimental design abilities in an experimental and comparison group. We measured significantly higher gains in advanced experimental design understanding in students in the experimental group. We believe this overlay model and EDAT factor analysis contribute a novel means to conduct and assess the effectiveness of authentic research experiences in an introductory course without major changes to the course curriculum and with minimal increases in faculty and student workloads. PMID:28904647

Extreme gravity tests with gravitational waves from compact binary coalescences: (II) ringdown

NASA Astrophysics Data System (ADS)

Berti, Emanuele; Yagi, Kent; Yang, Huan; Yunes, Nicolás

2018-05-01

The LIGO/Virgo detections of binary black hole mergers marked a watershed moment in astronomy, ushering in the era of precision tests of Kerr dynamics. We review theoretical and experimental challenges that must be overcome to carry out black hole spectroscopy with present and future gravitational wave detectors. Among other topics, we discuss quasinormal mode excitation in binary mergers, astrophysical event rates, tests of black hole dynamics in modified theories of gravity, parameterized "post-Kerr" ringdown tests, exotic compact objects, and proposed data analysis methods to improve spectroscopic tests of Kerr dynamics by stacking multiple events.

Examining the Stationarity Assumption for Statistically Downscaled Climate Projections of Precipitation

NASA Astrophysics Data System (ADS)

Wootten, A.; Dixon, K. W.; Lanzante, J. R.; Mcpherson, R. A.

2017-12-01

Empirical statistical downscaling (ESD) approaches attempt to refine global climate model (GCM) information via statistical relationships between observations and GCM simulations. The aim of such downscaling efforts is to create added-value climate projections by adding finer spatial detail and reducing biases. The results of statistical downscaling exercises are often used in impact assessments under the assumption that past performance provides an indicator of future results. Given prior research describing the danger of this assumption with regards to temperature, this study expands the perfect model experimental design from previous case studies to test the stationarity assumption with respect to precipitation. Assuming stationarity implies the performance of ESD methods are similar between the future projections and historical training. Case study results from four quantile-mapping based ESD methods demonstrate violations of the stationarity assumption for both central tendency and extremes of precipitation. These violations vary geographically and seasonally. For the four ESD methods tested the greatest challenges for downscaling of daily total precipitation projections occur in regions with limited precipitation and for extremes of precipitation along Southeast coastal regions. We conclude with a discussion of future expansion of the perfect model experimental design and the implications for improving ESD methods and providing guidance on the use of ESD techniques for impact assessments and decision-support.

Analytical and Experimental Evaluation of Digital Control Systems for the Semi-Span Super-Sonic Transport (S4T) Wind Tunnel Model

NASA Technical Reports Server (NTRS)

Wieseman, Carol D.; Christhilf, David; Perry, Boyd, III

2012-01-01

An important objective of the Semi-Span Super-Sonic Transport (S4T) wind tunnel model program was the demonstration of Flutter Suppression (FS), Gust Load Alleviation (GLA), and Ride Quality Enhancement (RQE). It was critical to evaluate the stability and robustness of these control laws analytically before testing them and experimentally while testing them to ensure safety of the model and the wind tunnel. MATLAB based software was applied to evaluate the performance of closed-loop systems in terms of stability and robustness. Existing software tools were extended to use analytical representations of the S4T and the control laws to analyze and evaluate the control laws prior to testing. Lessons were learned about the complex windtunnel model and experimental testing. The open-loop flutter boundary was determined from the closed-loop systems. A MATLAB/Simulink Simulation developed under the program is available for future work to improve the CPE process. This paper is one of a series of that comprise a special session, which summarizes the S4T wind-tunnel program.

Stability and Control Estimation Flight Test Results for the SR-71 Aircraft With Externally Mounted Experiments

NASA Technical Reports Server (NTRS)

Moes, Timothy R.; Iliff, Kenneth

2002-01-01

A maximum-likelihood output-error parameter estimation technique is used to obtain stability and control derivatives for the NASA Dryden Flight Research Center SR-71A airplane and for configurations that include experiments externally mounted to the top of the fuselage. This research is being done as part of the envelope clearance for the new experiment configurations. Flight data are obtained at speeds ranging from Mach 0.4 to Mach 3.0, with an extensive amount of test points at approximately Mach 1.0. Pilot-input pitch and yaw-roll doublets are used to obtain the data. This report defines the parameter estimation technique used, presents stability and control derivative results, and compares the derivatives for the three configurations tested. The experimental configurations studied generally show acceptable stability, control, trim, and handling qualities throughout the Mach regimes tested. The reduction of directional stability for the experimental configurations is the most significant aerodynamic effect measured and identified as a design constraint for future experimental configurations. This report also shows the significant effects of aircraft flexibility on the stability and control derivatives.

Investigation on bending failure to characterize crashworthiness of 6xxx-series aluminium sheet alloys with bending-tension test procedure

NASA Astrophysics Data System (ADS)

Henn, Philipp; Liewald, Mathias; Sindel, Manfred

2018-05-01

As lightweight design as well as crash performance are crucial to future car body design, exact material characterisation is important to use materials at their full potential and reach maximum efficiency. Within the scope of this paper, the potential of newly established bending-tension test procedure to characterise material crashworthiness is investigated. In this test setup for the determination of material failure, a buckling-bending test is coupled with a subsequent tensile test. If prior bending load is critical, tensile strength and elongation in the subsequent tensile test are dramatically reduced. The new test procedure therefore offers an applicable definition of failure as the incapacity of energy consumption in subsequent phases of the crash represents failure of a component. In addition to that, the correlation of loading condition with actual crash scenarios (buckling and free bending) is improved compared to three- point bending test. The potential of newly established bending-tension test procedure to characterise material crashworthiness is investigated in this experimental studys on two aluminium sheet alloys. Experimental results are validated with existing ductility characterisation from edge compression test.

Design, Progressive Modeling, Manufacture, and Testing of Composite Shield for Turbine Engine Blade Containment

NASA Technical Reports Server (NTRS)

Binienda, Wieslaw K.; Sancaktar, Erol; Roberts, Gary D. (Technical Monitor)

2002-01-01

An effective design methodology was established for composite jet engine containment structures. The methodology included the development of the full and reduced size prototypes, and FEA models of the containment structure, experimental and numerical examination of the modes of failure clue to turbine blade out event, identification of materials and design candidates for future industrial applications, and design and building of prototypes for testing and evaluation purposes.

Comparison of radar and infrared distance sensors for intelligent cruise control systems

NASA Astrophysics Data System (ADS)

Hoess, Alfred; Hosp, Werner; Rauner, Hans

1995-09-01

In this paper, infrared distance sensors are compared regarding technology, environmental, and practical aspects. Different methods for obtaining lateral resolution and covering the required detection range are presented for both sensor technologies. Possible positions for sensor installation at the test vehicle have been tested. Experimental results regarding cleaning devices and other environmental problems are presented. Finally, future aspects, e.g. speed over ground measurements or technological steps are discussed.

Experimental Results From a 2kW Brayton Power Conversion Unit

NASA Technical Reports Server (NTRS)

Hervol, David; Mason, Lee; Birchenough, Arthur

2003-01-01

This paper presents experimental test results from operation of a 2 kWe Brayton power conversion unit. The Brayton converter was developed for a solar dynamic power system flight experiment planned for the Mir Space Station in 1997. The flight experiment was cancelled, but the converter was tested at Glenn Research Center as part of the Solar Dynamic Ground Test Demonstration system which included a solar concentrator, heat receiver, and space radiator. In preparation for the current testing, the heat receiver was removed and replaced with an electrical resistance heater, simulating the thermal input of a steady-state nuclear source. The converter was operated over a full range of thermal input power levels and rotor speeds to generate an overall performance map. The converter unit will serve as the centerpiece of a Nuclear Electric Propulsion Testbed at Glenn. Future potential uses for the Testbed include high voltage electrical controller development, integrated electric thruster testing and advanced radiator demonstration testing to help guide high power Brayton technology development for Nuclear Electric Propulsion (NEP).

Animal experimentation in Japan: regulatory processes and application for microbiological studies.

PubMed

Takahashi-Omoe, H; Omoe, K

2007-07-01

We have conducted animal experimentation as a highly effective technique in biological studies. Also in microbiological studies, we have used experimentation to prevent and treat many infectious diseases in humans and animals. In Japan, the 'Law for the Humane Treatment and Management of Animals', which covers the consideration of the three R principles, refinement, replacement and reduction for an international humane approach to animal experimentation came into effect in June 2006. Looking towards the straightforward operation of the law in animal experimentation, three government ministries established new basic guidelines for experimentation performed in their jurisdictional research and testing facilities. For future microbiological studies involving animals in Japan, we need to perform animal experiments according to the basic guidelines in association with overseas management systems. In this report, we discussed essential actions for the management of animal experimentation in microbiological studies in Japan.

Detailed Results from the Flame Extinguishment Experiment (FLEX) March 2009 to December 2011

NASA Technical Reports Server (NTRS)

Dietrich, Daniel L.; Ferkul, Paul V.; Bryg, Victoria M.; Nayagam, M. Vedha; Hicks, Michael C.; Williams, Forman A.; Dryer, Frederick L.; Shaw, Benjamin D.; Choi, Mun Y.; Avedisian, C. Thomas

2015-01-01

The Flame Extinguishment Experiment (FLEX) program is a continuing set of experiments on droplet combustion, performed employing the Multi-User Droplet Combustion Apparatus (MDCA), inside the chamber of the Combustion Integrated Rack (CIR), which is located in the Destiny module of the International Space Station (ISS). This report describes the experimental hardware, the diagnostic equipment, the experimental procedures, and the methods of data analysis for FLEX. It also presents the results of the first 284 tests performed. The intent is not to interpret the experimental results but rather to make them available to the entire scientific community for possible future interpretations.

Empirical correlations of the performance of vapor-anode PX-series AMTEC cells

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

Huang, L.; Merrill, J.M.; Mayberry, C.

Power systems based on AMTEC technology will be used for future NASA missions, including a Pluto-Express (PX) or Europa mission planned for approximately year 2004. AMTEC technology may also be used as an alternative to photovoltaic based power systems for future Air Force missions. An extensive development program of Alkali-Metal Thermal-to-Electric Conversion (AMTEC) technology has been underway at the Vehicle Technologies Branch of the Air Force Research Laboratory (AFRL) in Albuquerque, New Mexico since 1992. Under this program, numerical modeling and experimental investigations of the performance of the various multi-BASE tube, vapor-anode AMTEC cells have been and are being performed.more » Vacuum testing of AMTEC cells at AFRL determines the effects of changing the hot and cold end temperatures, T{sub hot} and T{sub cold}, and applied external load, R{sub ext}, on the cell electric power output, current-voltage characteristics, and conversion efficiency. Test results have traditionally been used to provide feedback to cell designers, and to validate numerical models. The current work utilizes the test data to develop empirical correlations for cell output performance under various working conditions. Because the empirical correlations are developed directly from the experimental data, uncertainties arising from material properties that must be used in numerical modeling can be avoided. Empirical correlations of recent vapor-anode PX-series AMTEC cells have been developed. Based on AMTEC theory and the experimental data, the cell output power (as well as voltage and current) was correlated as a function of three parameters (T{sub hot}, T{sub cold}, and R{sub ext}) for a given cell. Correlations were developed for different cells (PX-3C, PX-3A, PX-G3, and PX-5A), and were in good agreement with experimental data for these cells. Use of these correlations can greatly reduce the testing required to determine electrical performance of a given type of AMTEC cell over a wide range of operating conditions.« less

A Framework for Testing Scientific Software: A Case Study of Testing Amsterdam Discrete Dipole Approximation Software

NASA Astrophysics Data System (ADS)

Shao, Hongbing

Software testing with scientific software systems often suffers from test oracle problem, i.e., lack of test oracles. Amsterdam discrete dipole approximation code (ADDA) is a scientific software system that can be used to simulate light scattering of scatterers of various types. Testing of ADDA suffers from "test oracle problem". In this thesis work, I established a testing framework to test scientific software systems and evaluated this framework using ADDA as a case study. To test ADDA, I first used CMMIE code as the pseudo oracle to test ADDA in simulating light scattering of a homogeneous sphere scatterer. Comparable results were obtained between ADDA and CMMIE code. This validated ADDA for use with homogeneous sphere scatterers. Then I used experimental result obtained for light scattering of a homogeneous sphere to validate use of ADDA with sphere scatterers. ADDA produced light scattering simulation comparable to the experimentally measured result. This further validated the use of ADDA for simulating light scattering of sphere scatterers. Then I used metamorphic testing to generate test cases covering scatterers of various geometries, orientations, homogeneity or non-homogeneity. ADDA was tested under each of these test cases and all tests passed. The use of statistical analysis together with metamorphic testing is discussed as a future direction. In short, using ADDA as a case study, I established a testing framework, including use of pseudo oracles, experimental results and the metamorphic testing techniques to test scientific software systems that suffer from test oracle problems. Each of these techniques is necessary and contributes to the testing of the software under test.

Test of localized nanagement for reducing deer browsing in forest regeneration areas

Treesearch

Brad F. Miller; Tyler A. Campbell; Ben R. Laseter; W.Mark Ford; Karl V. Miller

2010-01-01

White-tailed deer (Odocoileus virginianus) browsing in forest regeneration sites can affect current and future stand structure and species composition. Removal of deer social units (localized management) has been proposed as a strategy to alleviate deer overbrowsing in forest systems. We conducted an experimental localized removal in a high-density...

First experimental evidence of hydrodynamic tunneling of ultra–relativistic protons in extended solid copper target at the CERN HiRadMat facility

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

Schmidt, R.; Grenier, D.; Wollmann, D.

2014-08-15

A novel experiment has been performed at the CERN HiRadMat test facility to study the impact of the 440 GeV proton beam generated by the Super Proton Synchrotron on extended solid copper cylindrical targets. Substantial hydrodynamic tunneling of the protons in the target material has been observed that leads to significant lengthening of the projectile range, which confirms our previous theoretical predictions [N. A. Tahir et al., Phys. Rev. Spec. Top.-Accel. Beams 15, 051003 (2012)]. Simulation results show very good agreement with the experimental measurements. These results have very important implications on the machine protection design for powerful machines like themore » Large Hadron Collider (LHC), the future High Luminosity LHC, and the proposed huge 80 km circumference Future Circular Collider, which is currently being discussed at CERN. Another very interesting outcome of this work is that one may also study the field of High Energy Density Physics at this test facility.« less

Viscoelastic Response of the Titanium Alloy Ti-6-4: Experimental Identification of Time- and Rate-Dependent Reversible and Irreversible Deformation Regions

NASA Technical Reports Server (NTRS)

Lerch, Bradley A.; Arnold, Steven M.

2014-01-01

In support of an effort on damage prognosis, the viscoelastic behavior of Ti-6Al-4V (Ti-6-4) was investigated. This report documents the experimental characterization of this titanium alloy. Various uniaxial tests were conducted to low load levels over the temperature range of 20 to 538 C to define tensile, creep, and relaxation behavior. A range of strain rates (6x10(exp -7) to 0.001/s) were used to document rate effects. All tests were designed to include an unloading portion, followed by a hold time at temperature to allow recovery to occur either at zero stress or strain. The titanium alloy was found to exhibit viscoelastic behavior below the "yield" point and over the entire range of temperatures (although at lower temperatures the magnitude is extremely small). These experimental data will be used for future characterization of a viscoelastic model.

Beta Testing of CFD Code for the Analysis of Combustion Systems

NASA Technical Reports Server (NTRS)

Yee, Emma; Wey, Thomas

2015-01-01

A preliminary version of OpenNCC was tested to assess its accuracy in generating steady-state temperature fields for combustion systems at atmospheric conditions using three-dimensional tetrahedral meshes. Meshes were generated from a CAD model of a single-element lean-direct injection combustor, and the latest version of OpenNCC was used to calculate combustor temperature fields. OpenNCC was shown to be capable of generating sustainable reacting flames using a tetrahedral mesh, and the subsequent results were compared to experimental results. While nonreacting flow results closely matched experimental results, a significant discrepancy was present between the code's reacting flow results and experimental results. When wide air circulation regions with high velocities were present in the model, this appeared to create inaccurately high temperature fields. Conversely, low recirculation velocities caused low temperature profiles. These observations will aid in future modification of OpenNCC reacting flow input parameters to improve the accuracy of calculated temperature fields.

Characterization of Depleted-Uranium Strength and Damage Behavior

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

Gray, III, George T.; Chen, Shuh-Rong; Bronkhorst, Curt A.

2012-12-17

The intent of this report is to document the status of our knowledge of the mechanical and damage behavior of Depleted Uranium(DU hereafter). This report briefly summaries the motivation of the experimental and modeling research conducted at Los Alamos National Laboratory(LANL) on DU since the early 1980’s and thereafter the current experimental data quantifying the strength and damage behavior of DU as a function of a number of experimental variables including processing, strain rate, temperature, stress state, and shock prestraining. The effect of shock prestraining on the structure-property response of DU is described and the effect on post-shock mechanical behaviormore » of DU is discussed. The constitutive experimental data utilized to support the derivation of two constitutive strength (plasticity) models, the Preston-Tonks-Wallace (PTW) and Mechanical Threshold Stress (MTS) models, for both annealed and shock prestrained DU are detailed and the Taylor cylinder validation tests and finite-element modeling (FEM) utilized to validate these strength models is discussed. The similarities and differences in the PTW and MTS model descriptions for DU are discussed for both the annealed and shock prestrained conditions. Quasi-static tensile data as a function of triaxial constraint and spallation test data are described. An appendix additionally briefly describes low-pressure equation-of-state data for DU utilized to support the spallation experiments. The constitutive behavior of DU screw/bolt material is presented. The response of DU subjected to dynamic tensile extrusion testing as a function of temperature is also described. This integrated experimental technique is planned to provide an additional validation test in the future. The damage data as a function of triaxiality, tensile and spallation data, is thereafter utilized to support derivation of the Tensile Plasticity (TEPLA) damage model and simulations for comparison to the DU spallation data are presented. Finally, a discussion of future needs in the area of needed DU strength and damage research at LANL is presented to support the development of physically-based predictive strength and damage modeling capability.« less

Real-time maneuver optimization of space-based robots in a dynamic environment: Theory and on-orbit experiments

NASA Astrophysics Data System (ADS)

Chamitoff, Gregory E.; Saenz-Otero, Alvar; Katz, Jacob G.; Ulrich, Steve; Morrell, Benjamin J.; Gibbens, Peter W.

2018-01-01

This paper presents the development of a real-time path-planning optimization approach to controlling the motion of space-based robots. The algorithm is capable of planning three dimensional trajectories for a robot to navigate within complex surroundings that include numerous static and dynamic obstacles, path constraints and performance limitations. The methodology employs a unique transformation that enables rapid generation of feasible solutions for complex geometries, making it suitable for application to real-time operations and dynamic environments. This strategy was implemented on the Synchronized Position Hold Engage Reorient Experimental Satellite (SPHERES) test-bed on the International Space Station (ISS), and experimental testing was conducted onboard the ISS during Expedition 17 by the first author. Lessons learned from the on-orbit tests were used to further refine the algorithm for future implementations.

The evaluation of a number of prototypes for the free-tip rotor constant-moment controller

NASA Technical Reports Server (NTRS)

Young, L. A.

1986-01-01

The development of several prototypes of a constant moment controller, a critical component of the free-tip rotor (FTR) concept, is described. Also presented are the experimental results of a whirl test designed to select a final controller configuration to be included in a future wind-tunnel test of this innovative rotor system. A brief explanation of the FTR concept and its history are included. The paper documents the controller design constraints, each prototype's operating principle, the evaluation test, and the individual prototype test results. A recommended design is identified, along with the selection rationale.

Fracture simulation of elastomer blended polypropylene based on elastoviscoplastic constitutive equation with craze and tensile softening law

NASA Astrophysics Data System (ADS)

Mae, H.

2006-08-01

The strong strain-rate dependence, neck propagation and craze evolution characterize the large plastic deformation and fracture behavior of polymer. In the latest study, Kobayashi, Tomii and Shizawa suggested the elastoviscoplastic constitutive equation based on craze evolution and annihilation and then applied it to the plane strain issue of polymer. In the previous study, the author applied their suggested elastoviscoplastic constitutive equation with craze effect to the three dimensional shell and then showed that the load displacement history was in good agreement with the experimental result including only microscopic crack such as crazes. For the future industrial applications, the macroscopic crack has to be taken into account. Thus, the main objective of this study is to propose the tensile softening equation and then add it to the elastoviscoplastic constitutive equation with craze effect so that the load displacement history can be roughly simulated during the macroscopic crack propagation. The tested material in this study is the elastomer blended polypropylene used in the interior and exterior of automobiles. First, the material properties are obtained based on the tensile test results at wide range of strain rates: 10 - 4-102 (1/sec). Next, the compact tension test is conducted and then the tensile softening parameters are fixed. Then, the dart impact test is carried out in order to obtain the load displacement history and also observe the macroscopic crack propagation at high strain rate. Finally, the fracture behavior is simulated and then compared with the experimental results. It is shown that the predictions of the constitutive equation with the proposed tensile softening equation are in good agreement with the experimental results for the future industrial applications.

Plasma Liner Development for MTF Applications: A Status Report

NASA Technical Reports Server (NTRS)

Eskridge, R. E.; Thio, Y. F.; Lee, M.; Martin, A.; Smith, J. W.; Griffin, S. T.; Schafer, Charles (Technical Monitor)

2001-01-01

An experimental plasma gun for Magnetic Target Fusion (MTF) applications under development at the NASA Marshall Space Flight Center is described. This gun has been tested experimentally and plasma jet velocities of approximately 50 km/sec have been obtained. The plasma jet structure has been photographed with 10 ns exposure times to reveal a stable and repeatable plasma structure. Data for velocity profile information has been obtained using light pipes embedded in the gun walls to record the plasma transit at various barrel locations. A high speed triggering system has been developed and tested as a means of reducing the gun "jitter". This jitter has been characterized and future work for second generation "ultra-low jitter" gun development is identified.

Initial characterization of an Experimental Referee Broadened-Specification (ERBS) aviation turbine fuel

NASA Technical Reports Server (NTRS)

Prok, G. M.; Seng, G. T.

1980-01-01

Characterization data and a hydrocarbon compositional analysis are presented for a research test fuel designated as an experimental referee broadened-specification aviation turbine fuel. This research fuel, which is a special blend of kerosene and hydrotreated catalytic gas oil, is a hypothetical representation of a future fuel should it become necessary to broaden current kerojet specifications. It is used as a reference fuel in research investigations into the effects of fuel property variations on the performance and durability of jet aircraft components, including combustors and fuel systems.

Adaptive antenna arrays for satellite communication

NASA Technical Reports Server (NTRS)

Gupta, Inder J.

1989-01-01

The feasibility of using adaptive antenna arrays to provide interference protection in satellite communications was studied. The feedback loops as well as the sample matric inversion (SMI) algorithm for weight control were studied. Appropriate modifications in the two were made to achieve the required interference suppression. An experimental system was built to test the modified feedback loops and the modified SMI algorithm. The performance of the experimental system was evaluated using bench generated signals and signals received from TVRO geosynchronous satellites. A summary of results is given. Some suggestions for future work are also presented.

Mainstreaming Caenorhabditis elegans in experimental evolution.

PubMed

Gray, Jeremy C; Cutter, Asher D

2014-03-07

Experimental evolution provides a powerful manipulative tool for probing evolutionary process and mechanism. As this approach to hypothesis testing has taken purchase in biology, so too has the number of experimental systems that use it, each with its own unique strengths and weaknesses. The depth of biological knowledge about Caenorhabditis nematodes, combined with their laboratory tractability, positions them well for exploiting experimental evolution in animal systems to understand deep questions in evolution and ecology, as well as in molecular genetics and systems biology. To date, Caenorhabditis elegans and related species have proved themselves in experimental evolution studies of the process of mutation, host-pathogen coevolution, mating system evolution and life-history theory. Yet these organisms are not broadly recognized for their utility for evolution experiments and remain underexploited. Here, we outline this experimental evolution work undertaken so far in Caenorhabditis, detail simple methodological tricks that can be exploited and identify research areas that are ripe for future discovery.

INTENTION TO EXPERIMENT WITH E-CIGARETTES IN A CROSS-SECTIONAL SURVEY OF UNDERGRADUATE UNIVERSITY STUDENTS IN HUNGARY

PubMed Central

Pénzes, Melinda; Foley, Kristie L.; Balázs, Péter; Urbán, Róbert

2016-01-01

Background Electronic cigarettes are often used to promote cessation. Only a few studies have explored the motivations for e-cigarette experimentation among young adults. Objectives The goals of this study were to assess the intention to try e-cigarettes among Hungarian university students and to develop a motivational scale to measure vulnerability to e-cigarette experimentation. Methods 826 Hungarian university students completed an internet-based survey in 2013 to measure motives for trying e-cigarettes. We conducted exploratory factor analyses and identified factors that promote and deter experimentation. Logistic regression analysis was performed to test the concurrent predictive validity of the identified motivational factors and we used these factors to predict e-cigarette experimentation, controlling for other known correlates of e-cigarette use. Results 24.9% of the participants have ever tried an e-cigarette and 17.2% of current nonsmokers experimented with the product. Almost 11% of respondents intended to try an e-cigarette in the future, yet only 0.6% were current e-cigarette users. Six factors were identified in the motivational scale for experimentation, four that promote usage (health benefits/smoking cessation; curiosity/taste variety; perceived social norms; convenience when smoking is prohibited) and two that deter usage (chemical hazard; danger of dependence). In a logistic regression analysis, the curiosity/taste factor was the only motivational factor significantly associated with the intention to try e-cigarettes in the future. Conclusions This is the first study to test a motivational scale about what motivates e-cigarettes usage among university students. Additional research is needed to better understand these factors and their influence on e-cigarette uptake. PMID:27159776

A design of experiments test to define critical spray cleaning parameters for Brulin 815 GD and Jettacin cleaners

NASA Technical Reports Server (NTRS)

Keen, Jill M.; Evans, Kurt B.; Schiffman, Robert L.; Deweese, C. Darrell; Prince, Michael E.

1995-01-01

Experimental design testing was conducted to identify critical parameters of an aqueous spray process intended for cleaning solid rocket motor metal components (steel and aluminum). A two-level, six-parameter, fractional factorial matrix was constructed and conducted for two cleaners, Brulin 815 GD and Diversey Jettacin. The matrix parameters included cleaner temperature and concentration, wash density, wash pressure, rinse pressure, and dishwasher type. Other spray parameters: nozzle stand-off, rinse water temperature, wash and rinse time, dry conditions, and type of rinse water (deionized) were held constant. Matrix response testing utilized discriminating bond specimens (fracture energy and tensile adhesion strength) which represent critical production bond lines. Overall, Jettacin spray cleaning was insensitive to the range of conditions tested for all parameters and exhibited bond strengths significantly above the TCA test baseline for all bond lines tested. Brulin 815 was sensitive to cleaning temperature, but produced bond strengths above the TCA test baseline even at the lower temperatures. Ultimately, the experimental design database was utilized to recommend process parameter settings for future aqueous spray cleaning characterization work.

The effect of reflective writing interventions on the critical thinking skills and dispositions of baccalaureate nursing students.

PubMed

Naber, Jessica; Wyatt, Tami H

2014-01-01

The importance of critical thinking is well-documented by the American Association of Colleges of Nursing and the National League for Nursing. Reflective writing is often used to increase understanding and analytical ability. The lack of empirical evidence about the effect of reflective writing interventions on critical thinking supports the examination of this concept. Study objectives were: This study used an experimental, pretest-posttest design. The setting was two schools of nursing at universities in the southern United States. The convenience sample included 70 fourth-semester students in baccalaureate nursing programs. Randomly assigned control and experimental groups completed the California Critical Thinking Skills Test (CCTST) and the California Critical Thinking Dispositions Inventory Test (CCTDI). The experimental group completed six reflective writing assignments. Both groups completed the two tests again. Results showed that the experimental group had a significant increase (p=0.03) on the truthseeking subscale of the CCTDI when compared to the control group. The experimental group's scores increased on four CCTST subscales and were higher than the control group's on three CCTST subscales. The results of this study make it imperative for nursing schools to consider including reflective writing-especially assignments based on Paul's (1993) model-in nursing courses. If future studies, testing over longer periods of time, show significant increases in critical thinking, those interventions could be incorporated into nursing curriculum and change the way nurse educators evaluate students. Copyright © 2013 Elsevier Ltd. All rights reserved.

Qualitative thermal characterization and cooling of lithium batteries for electric vehicles

NASA Astrophysics Data System (ADS)

Mariani, A.; D'Annibale, F.; Boccardi, G.; Celata, G. P.; Menale, C.; Bubbico, R.; Vellucci, F.

2014-04-01

The paper deals with the cooling of batteries. The first step was the thermal characterization of a single cell of the module, which consists in the detection of the thermal field by means of thermographic tests during electric charging and discharging. The purpose was to identify possible critical hot points and to evaluate the cooling demand during the normal operation of an electric car. After that, a study on the optimal configuration to obtain the flattening of the temperature profile and to avoid hot points was executed. An experimental plant for cooling capacity evaluation of the batteries, using air as cooling fluid, was realized in our laboratory in ENEA Casaccia. The plant is designed to allow testing at different flow rate and temperatures of the cooling air, useful for the assessment of operative thermal limits in different working conditions. Another experimental facility was built to evaluate the thermal behaviour changes with water as cooling fluid. Experimental tests were carried out on the LiFePO4 batteries, under different electric working conditions using the two loops. In the future, different type of batteries will be tested and the influence of various parameters on the heat transfer will be assessed for possible optimal operative solutions.

Transonic Blunt Body Aerodynamic Coefficients Computation

NASA Astrophysics Data System (ADS)

Sancho, Jorge; Vargas, M.; Gonzalez, Ezequiel; Rodriguez, Manuel

2011-05-01

In the framework of EXPERT (European Experimental Re-entry Test-bed) accurate transonic aerodynamic coefficients are of paramount importance for the correct trajectory assessment and parachute deployment. A combined CFD (Computational Fluid Dynamics) modelling and experimental campaign strategy was selected to obtain accurate coefficients. A preliminary set of coefficients were obtained by CFD Euler inviscid computation. Then experimental campaign was performed at DNW facilities at NLR. A profound review of the CFD modelling was done lighten up by WTT results, aimed to obtain reliable values of the coefficients in the future (specially the pitching moment). Study includes different turbulence modelling and mesh sensitivity analysis. Comparison with the WTT results is explored, and lessons learnt are collected.

Development of Supersonic Vehicle for Demonstration of a Precooled Turbojet Engine

NASA Astrophysics Data System (ADS)

Sawai, Shujiro; Fujita, Kazuhisa; Kobayashi, Hiroaki; Sakai, Shin'ichiro; Bando, Nobutaka; Kadooka, Shouhei; Tsuboi, Nobuyuki; Miyaji, Koji; Uchiyama, Taku; Hashimoto, Tatsuaki

JAXA is developing Mach 5 hypersonic turbojet engine technology that can be applied in a future hypersonic transport. Now, Jet Engine Technology Research Center of JAXA conducts the experimental study using a 1 / 10 scale-model engine. In parallel to engine development activities, a new supersonic flight-testing vehicle for the hypersonic turbojet engine is under development since 2004. In this paper, the system configuration of the flight-testing vehicle is outlined and development status is reported.

High-speed noncontacting instrumentation for jet engine testing

NASA Astrophysics Data System (ADS)

Scotto, M. J.; Eismeier, M. E.

1980-03-01

This paper discusses high-speed, noncontacting instrumentation systems for measuring the operating characteristics of jet engines. The discussion includes optical pyrometers for measuring blade surface temperatures, capacitance clearanceometers for measuring blade tip clearance and vibration, and optoelectronic systems for measuring blade flex and torsion. In addition, engine characteristics that mandate the use of such unique instrumentation are pointed out as well as the shortcomings of conventional noncontacting devices. Experimental data taken during engine testing are presented and recommendations for future development discussed.

SLAC All Access: FACET

ScienceCinema

Hogan, Mark

2018-02-13

SLAC's Facility for Advanced Accelerator Experimental Tests, or FACET, is a test-bed where researchers are developing the technologies required for particle accelerators of the future. Scientists from all over the world come to explore ways of improving the power and efficiency of the particle accelerators used in basic research, medicine, industry and other areas important to society. In this video, Mark Hogan, head of SLAC's Advanced Accelerator Research Department, offers a glimpse into FACET, which uses part of SLAC's historic two-mile-long linear accelerator.

BETA (Bitter Electromagnet Testing Apparatus) Design and Testing

NASA Astrophysics Data System (ADS)

Bates, Evan; Birmingham, William; Rivera, William; Romero-Talamas, Carlos

2016-10-01

BETA is a 1T water cooled Bitter-type magnetic system that has been designed and constructed at the Dusty Plasma Laboratory of the University of Maryland, Baltimore County to serve as a prototype of a scaled 10T version. Currently the system is undergoing magnetic, thermal and mechanical testing to ensure safe operating conditions and to prove analytical design optimizations. These magnets will function as experimental tools for future dusty plasma based and collaborative experiments. An overview of design methods used for building a custom made Bitter magnet with user defined experimental constraints is reviewed. The three main design methods consist of minimizing the following: ohmic power, peak conductor temperatures, and stresses induced by Lorentz forces. We will also discuss the design of BETA which includes: the magnet core, pressure vessel, cooling system, power storage bank, high powered switching system, diagnostics with safety cutoff feedback, and data acquisition (DAQ)/magnet control Matlab code. Furthermore, we present experimental data from diagnostics for validation of our analytical preliminary design methodologies and finite element analysis calculations. BETA will contribute to the knowledge necessary to finalize the 10 T magnet design.

Scintillator Detector Development at Central Michigan University

NASA Astrophysics Data System (ADS)

McClain, David; Estrade, Alfredo; Neupane, Shree

2017-09-01

Experimental nuclear physics relies both on the accuracy and precision of the instruments for radiation detection used in experimental setups. At Central Michigan University we have setup a lab to work with scintillator detectors for radioactive ion beam experiments, using a Picosecond Laser and radioactive sources for testing. We have tested the resolution for prototypes of large area scintillators that could be used for fast timing measurements in the focal plane of spectrometers, such as the future High Rigidity Spectrometer at the Facility for Rare Isotope Beams (FRIB). We measured the resolution as a function of the length of the detector, and also the position of the beam along the scintillator. We have also designed a scintillating detector to veto light ion background in beta-decay experiments with the Advanced Implantation Detector Array (AIDA) at RIKEN in Japan. We tested different configurations of Silicon Photomultipliers and scintillating fiber optics to find the best detection efficiency.

Clinical trials transparency and the Trial and Experimental Studies Transparency (TEST) act.

PubMed

Logvinov, Ilana

2014-03-01

Clinical trial research is the cornerstone for successful advancement of medicine that provides hope for millions of people in the future. Full transparency in clinical trials may allow independent investigators to evaluate study designs, perform additional analysis of data, and potentially eliminate duplicate studies. Current regulatory system and publishers rely on investigators and pharmaceutical industries for complete and accurate reporting of results from completed clinical trials. Legislation seems to be the only way to enforce mandatory disclosure of results. The Trial and Experimental Studies Transparency (TEST) Act of 2012 was introduced to the legislators in the United States to promote greater transparency in research industry. Public safety and advancement of science are the driving forces for the proposed policy change. The TEST Act may benefit the society and researchers; however, there are major concerns with participants' privacy and intellectual property protection. Copyright © 2014 Elsevier Inc. All rights reserved.

In-house experiments in large space structures at the Air Force Wright Aeronautical Laboratories Flight Dynamics Laboratory

NASA Technical Reports Server (NTRS)

Gordon, Robert W.; Ozguner, Umit; Yurkovich, Steven

1989-01-01

The Flight Dynamics Laboratory is committed to an in-house, experimental investigation of several technical areas critical to the dynamic performance of future Air Force large space structures. The advanced beam experiment was successfully completed and provided much experience in the implementation of active control approaches on real hardware. A series of experiments is under way in evaluating ground test methods on the 12 meter trusses with significant passive damping. Ground simulated zero-g response data from the undamped truss will be compared directly with true zero-g flight test data. The performance of several leading active control approaches will be measured and compared on one of the trusses in the presence of significant passive damping. In the future, the PACOSS dynamic test article will be set up as a test bed for the evaluation of system identification and control techniques on a complex, representative structure with high modal density and significant passive damping.

Can the experimental evolution programme help us elucidate the genetic basis of adaptation in nature?

PubMed

Bailey, Susan F; Bataillon, Thomas

2016-01-01

There have been a variety of approaches taken to try to characterize and identify the genetic basis of adaptation in nature, spanning theoretical models, experimental evolution studies and direct tests of natural populations. Theoretical models can provide formalized and detailed hypotheses regarding evolutionary processes and patterns, from which experimental evolution studies can then provide important proofs of concepts and characterize what is biologically reasonable. Genetic and genomic data from natural populations then allow for the identification of the particular factors that have and continue to play an important role in shaping adaptive evolution in the natural world. Further to this, experimental evolution studies allow for tests of theories that may be difficult or impossible to test in natural populations for logistical and methodological reasons and can even generate new insights, suggesting further refinement of existing theories. However, as experimental evolution studies often take place in a very particular set of controlled conditions--that is simple environments, a small range of usually asexual species, relatively short timescales--the question remains as to how applicable these experimental results are to natural populations. In this review, we discuss important insights coming from experimental evolution, focusing on four key topics tied to the evolutionary genetics of adaptation, and within those topics, we discuss the extent to which the experimental work compliments and informs natural population studies. We finish by making suggestions for future work in particular a need for natural population genomic time series data, as well as the necessity for studies that combine both experimental evolution and natural population approaches. © 2015 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

Study of lubricant circulation in HVAC systems. Volume 1: Description of technical effort and results; Final technical report, March 1995--April 1996

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

Biancardi, F.R.; Michels, H.H.; Sienel, T.H.

1996-10-01

The purpose of this program was to conduct experimental and analytical efforts to determine lubricant circulation characteristics of new HFC/POE pairs and HFC/mineral oil pairs in a representative central residential HVAC system and to compare their behavior with the traditional HCFC-22/mineral oil (refrigerant/lubricant) pair. A dynamic test facility was designed and built to conduct the experimental efforts. This facility provided a unique capability to visually and physically measure oil circulation rates, on-line, in operating systems. A unique on-line ultraviolet-based measurement device was used to obtain detailed data on the rate and level of lubricant oil circulated within the operating heatmore » pump system. The experimental and analytical data developed during the program are presented as a function of vapor velocity, refrigerant/lubricant viscosity, system features and equipment. Both visual observations and instrumentation were used to understand ``worst case`` oil circulation situations. This report is presented in two volumes. Volume 1 contains a complete description of the program scope, objective, test results summary, conclusions, description of test facility and recommendations for future effort. Volume 2 contains all of the program test data essentially as taken from the laboratory dynamic test facility during the sequence of runs.« less

Children's differential susceptibility to parenting: An experimental test of "for better and for worse".

PubMed

Slagt, Meike; Dubas, Judith Semon; van Aken, Marcel A G; Ellis, Bruce J; Deković, Maja

2017-02-01

Differential susceptibility theory proposes that a subset of individuals exist who display enhanced susceptibility to both negative (risk-promoting) and positive (development-enhancing) environments. This experiment represents the first attempt to directly test this assumption by exposing children in the experimental group to both negative and positive feedback using puppet role-plays. It thereby serves as an empirical test as well as a methodological primer for testing differential susceptibility. Dutch children (N=190, 45.3% girls) between the ages of 4 and 6years participated. We examined whether negative and positive feedback would differentially affect changes in positive and negative affect, in prosocial and antisocial intentions and behavior, depending on children's negative emotionality. Results show that on hearing negative feedback, children in the experimental group increased in negative affect and decreased in positive affect more strongly than children in the control group. On hearing positive feedback, children in the experimental group tended to increase in positive affect and decrease in prosocial behavior. However, changes in response to negative or positive feedback did not depend on children's negative emotionality. Moreover, using reliable change scores, we found support for a subset of "vulnerable" children but not for a subset of "susceptible" children. The findings offer suggestions to guide future differential susceptibility experiments. Copyright © 2016 Elsevier Inc. All rights reserved.

Magnus effect: An overview of its past and future practical applications, 1850-1985, volumes 1 and 2

NASA Astrophysics Data System (ADS)

Borg, J.

The report is in two volumes and is intended to present the known data and past and future applications of Magnus effect devices. (Magnus effect devices are very high lift devices which can be used in applications where airfoils are currently used.) This first volume includes the history of Magnus effect devices, theory and principles, a significant patent review, practical marine applications, formulas and experimental data, comparisons of Magnus effect and other state-of-the-art devices, identification of further testing needed, and a proposed test program. Appendices include rudder research and a literature critique. The second volume is a collection of the drawings for 39 magnus effect patents plus a critique of each patent evaluating its potential, especially for marine applications.

Aerothermodynamic Characteristics of Boundary Layer Transition and Trip Effectiveness of the HIFiRE Flight 5 Vehicle

NASA Technical Reports Server (NTRS)

Berger, Karen T.; Rufer, Shann J.; Kimmel, Roger; Adamczak, David

2009-01-01

An experimental wind tunnel test was conducted in the NASA Langley Research Center s 20-Inch Mach 6 Tunnel in support of the Hypersonic International Flight Research Experimentation Program. The information in this report is focused on the Flight 5 configuration, one in a series of flight experiments. This report documents experimental measurements made over a range of Reynolds numbers and angles of attack on several scaled ceramic heat transfer models of the Flight 5 vehicle. The heat transfer rate was measured using global phosphor thermography and the resulting images and heat transfer rate distributions were used to infer the state of the boundary layer on the windside, leeside and side surfaces. Boundary layer trips were used to force the boundary layer turbulent, and a study was conducted to determine the effectiveness of the trips with various heights. The experimental data highlighted in this test report were used determine the allowable roughness height for both the windside and side surfaces of the vehicle as well as provide for future tunnel-to-tunnel comparisons.

Laboratory MCAO Test-Bed for Developing Wavefront Sensing Concepts.

PubMed

Goncharov, A V; Dainty, J C; Esposito, S; Puglisi, A

2005-07-11

An experimental optical bench test-bed for developing new wavefront sensing concepts for Multi-Conjugate Adaptive Optics (MCAO) systems is described. The main objective is to resolve imaging problems associated with wavefront sensing of the atmospheric turbulence for future MCAO systems on Extremely Large Telescopes (ELTs). The test-bed incorporates five reference sources, two deformable mirrors (DMs) and atmospheric phase screens to simulate a scaled version of a 10-m adaptive telescope operating at the K band. A recently proposed compact tomographic wavefront sensor is employed for star-oriented DMs control in the MCAO system. The MCAO test-bed is used to verify the feasibility of the wavefront sensing concept utilizing a field lenslet array for multi-pupil imaging on a single detector. First experimental results of MCAO correction with the proposed tomographic wavefront sensor are presented and compared to the theoretical prediction based on the characteristics of the phase screens, actuator density of the DMs and the guide star configuration.

Achieving external validity in home advantage research: generalizing crowd noise effects

PubMed Central

Myers, Tony D.

2014-01-01

Different factors have been postulated to explain the home advantage phenomenon in sport. One plausible explanation investigated has been the influence of a partisan home crowd on sports officials' decisions. Different types of studies have tested the crowd influence hypothesis including purposefully designed experiments. However, while experimental studies investigating crowd influences have high levels of internal validity, they suffer from a lack of external validity; decision-making in a laboratory setting bearing little resemblance to decision-making in live sports settings. This focused review initially considers threats to external validity in applied and theoretical experimental research. Discussing how such threats can be addressed using representative design by focusing on a recently published study that arguably provides the first experimental evidence of the impact of live crowd noise on officials in sport. The findings of this controlled experiment conducted in a real tournament setting offer a level of confirmation of the findings of laboratory studies in the area. Finally directions for future research and the future conduct of crowd noise studies are discussed. PMID:24917839

Blade Surface Pressure Distributions in a Rocket Engine Turbine: Experimental Work With On-Blade Pressure Transducers

NASA Technical Reports Server (NTRS)

Hudson, Susan T.; Zoladz, Thomas F.; Griffin, Lisa W.; Turner, James E. (Technical Monitor)

2000-01-01

Understanding the unsteady aspects of turbine rotor flowfields is critical to successful future turbine designs. A technology program was conducted at NASA's Marshall Space Flight Center to increase the understanding of unsteady environments for rocket engine turbines. The experimental program involved instrumenting turbine rotor blades with surface-mounted high frequency response pressure transducers. The turbine model was then tested to measure the unsteady pressures on the rotor blades. The data obtained from the experimental program is unique in three respects. First, much more unsteady data was obtained (several minutes per set point) than has been possible in the past. Also, two independent unsteady data acquisition systems and fundamental signal processing approaches were used. Finally, an extensive steady performance database existed for the turbine model. This allowed an evaluation of the effect of the on-blade instrumentation on the turbine's performance. This unique data set, the lessons learned for acquiring this type of data, and the improvements made to the data analysis and prediction tools will contribute to future turbine programs such as those for reusable launch vehicles.

NASA electronic message experiment and study: Detailed test plans

NASA Technical Reports Server (NTRS)

1979-01-01

A methodology for evaluating the utility of high speed digital facsimile as a component of the projected NASA-wide electronic message network is presented. Equipment checkout, operator familiarization, pretest calibration, and the development of procedures are addressed. An experimental test program of the facsimile message service which will carry duplicates of the actual messages sent by other means is highlighted. Also, an operational test program during which messages will be sent on a regular basis in order to accumulate the information that will be used to evaluate system performance and project future growth is described.

A practical guide and perspectives on the use of experimental pain modalities with children and adolescents

PubMed Central

Birnie, Kathryn A; Caes, Line; Wilson, Anna C; Williams, Sara E; Chambers, Christine T

2014-01-01

SUMMARY Use of experimental pain is vital for addressing research questions that would otherwise be impossible to examine in the real world. Experimental induction of pain in children is highly scrutinized given the potential for harm and lack of direct benefit to a vulnerable population. However, its use has critically advanced our understanding of the mechanisms, assessment and treatment of pain in both healthy and chronically ill children. This article introduces various experimental pain modalities, including the cold pressor task, the water load symptom provocation test, thermal pain, pressure pain and conditioned pain modulation, and discusses their application for use with children and adolescents. It addresses practical implementation and ethical issues, as well as the advantages and disadvantages offered by each task. The incredible potential for future research is discussed given the array of experimental pain modalities now available to pediatric researchers. PMID:24641434

AGR-1 Thermocouple Data Analysis

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

Jeff Einerson

2012-05-01

This report documents an effort to analyze measured and simulated data obtained in the Advanced Gas Reactor (AGR) fuel irradiation test program conducted in the INL's Advanced Test Reactor (ATR) to support the Next Generation Nuclear Plant (NGNP) R&D program. The work follows up on a previous study (Pham and Einerson, 2010), in which statistical analysis methods were applied for AGR-1 thermocouple data qualification. The present work exercises the idea that, while recognizing uncertainties inherent in physics and thermal simulations of the AGR-1 test, results of the numerical simulations can be used in combination with the statistical analysis methods tomore » further improve qualification of measured data. Additionally, the combined analysis of measured and simulation data can generate insights about simulation model uncertainty that can be useful for model improvement. This report also describes an experimental control procedure to maintain fuel target temperature in the future AGR tests using regression relationships that include simulation results. The report is organized into four chapters. Chapter 1 introduces the AGR Fuel Development and Qualification program, AGR-1 test configuration and test procedure, overview of AGR-1 measured data, and overview of physics and thermal simulation, including modeling assumptions and uncertainties. A brief summary of statistical analysis methods developed in (Pham and Einerson 2010) for AGR-1 measured data qualification within NGNP Data Management and Analysis System (NDMAS) is also included for completeness. Chapters 2-3 describe and discuss cases, in which the combined use of experimental and simulation data is realized. A set of issues associated with measurement and modeling uncertainties resulted from the combined analysis are identified. This includes demonstration that such a combined analysis led to important insights for reducing uncertainty in presentation of AGR-1 measured data (Chapter 2) and interpretation of simulation results (Chapter 3). The statistics-based simulation-aided experimental control procedure described for the future AGR tests is developed and demonstrated in Chapter 4. The procedure for controlling the target fuel temperature (capsule peak or average) is based on regression functions of thermocouple readings and other relevant parameters and accounting for possible changes in both physical and thermal conditions and in instrument performance.« less

Spontaneous C P -violation in the simplest little Higgs model and its future collider tests: The scalar sector

NASA Astrophysics Data System (ADS)

Mao, Ying-nan

2018-04-01

We propose spontaneous C P violation in the simplest little Higgs model. In this model, the pseudoscalar field can acquire a nonzero vacuum expectation value. This leads to a mixing between the two scalars with different C P charge, which means that spontaneous C P violation occurs. It is also a connection between the composite Higgs mechanism and C P violation. Facing the experimental constraints, the model is still viable for both scenarios in which the extra scalar appears below or around the electroweak scale. We also discuss the future collider tests of C P violation in the scalar sector through measuring h2Z Z and h1h2Z' vertices (see the definitions of the particles in the text), which provide new motivations for future e+e- and p p colliders. This also shows the importance of the vector-vector-scalar- and vector-scalar-scalar-type vertices in discovering C P -violation effects in the scalar sector.

The "Downside" of Women Empowerment in India: An Experimental Inquiry into the Role of Expectations

ERIC Educational Resources Information Center

van Kempen, Luuk

2009-01-01

The paper reports on a field experiment conducted among poor women organized in self-help groups in the north-east of India. The experiment tests in a simple game whether overly optimistic expectations with respect to the benefits of exercising agency reduces one's appreciation of remaining with agency in the future. If so, unrealistic…

Mind Transplants Or: The Role of Computer Assisted Instruction in the Future of the Library.

ERIC Educational Resources Information Center

Lyon, Becky J.

Computer assisted instruction (CAI) may well represent the next phase in the involvement of the library or learning resources center with media and the educational process. The Lister Hill Center Experimental CAI Network was established in July, 1972, on the recommendation of the National Library of Medicine, to test the feasibility of sharing CAI…

Distributed digital signal processors for multi-body structures

NASA Technical Reports Server (NTRS)

Lee, Gordon K.

1990-01-01

Several digital filter designs were investigated which may be used to process sensor data from large space structures and to design digital hardware to implement the distributed signal processing architecture. Several experimental tests articles are available at NASA Langley Research Center to evaluate these designs. A summary of some of the digital filter designs is presented, an evaluation of their characteristics relative to control design is discussed, and candidate hardware microcontroller/microcomputer components are given. Future activities include software evaluation of the digital filter designs and actual hardware inplementation of some of the signal processor algorithms on an experimental testbed at NASA Langley.

Phenomenological study of the isovector tensor meson family

NASA Astrophysics Data System (ADS)

Pang, Cheng-Qun; He, Li-Ping; Liu, Xiang; Matsuki, Takayuki

2014-07-01

In this work, we study all the observed a2 states and group them into the a2 meson family, where their total and two-body Okubo-Zweig-Iizuka allowed strong decay partial widths are calculated via the quark pair creation model. Taking into account the present experimental data, we further give the corresponding phenomenological analysis, which is valuable to test whether each a2 state can be assigned into the a2 meson family. What is more important is that the prediction of their decay behaviors will be helpful for future experimental study of the a2 states.

[Theoretical and methodological bases for formation of future drivers 'readiness to application of physical-rehabilitation technologies].

PubMed

Yemets, Anatoliy V; Donchenko, Viktoriya I; Scrinick, Eugenia O

2018-01-01

Introduction: Experimental work is aimed at introducing theoretical and methodological foundations for the professional training of the future doctor. The aim: Identify the dynamics of quantitative and qualitative indicators of the readiness of a specialist in medicine. Materials and methods: The article presents the course and results of the experimental work of the conditions of forming the readiness of future specialists in medicine. Results: Our methodical bases for studying the disciplines of the general practice and specialized professional stage of experimental training of future physicians have been worked out. Conclusions: It is developed taking into account the peculiarities of future physician training of materials for various stages of experimental implementation in the educational process of higher medical educational institutions.

Impact of theoretical assumptions in the determination of the neutrino effective number from future CMB measurements

NASA Astrophysics Data System (ADS)

Capparelli, Ludovico; Di Valentino, Eleonora; Melchiorri, Alessandro; Chluba, Jens

2018-03-01

One of the major goals of future cosmic microwave background (CMB) measurements is the accurate determination of the effective number of neutrinos Neff. Reaching an experimental sensitivity of Δ Neff=0.013 could indeed falsify the presence of any nonstandard relativistic particles at 95% C.L. In this paper, we test how this future constraint can be affected by the removal of two common assumptions: a negligible running of the inflationary spectral index nrun and a precise determination of the neutron lifetime τn. We first show that the constraints on Neff could be significantly biased by the unaccounted presence of a running of the spectral index. Considering the Stage-IV experiment, a negative running of d n /d ln k =-0.002 could mimic a positive variation of Δ Neff=0.03 . Moreover, given the current discrepancies between experimental measurements of the neutron lifetime τn, we show that the assumption of a conservative error of Δ τn˜10 s could cause a systematic error of Δ Neff=0.02 . Complementary cosmological constraints on the running of the spectral index and a solution to the neutron lifetime discrepancy are therefore needed for an accurate and reliable future CMB bound of Neff at the percent level.

The influence of risk labeling on risk perception and willingness to seek help in an experimental simulation of preventive medical examinations.

PubMed

Nieuwenhuijsen, Karen; Hulshof, Carel T; Sluiter, Judith K

2018-07-01

To study the influence of the presentation of results of a preventive medical examination on risk perception and willingness to seek help for work-related fatigue or being overweight. A factorial design experiment was conducted, presenting workers (n = 82) with vignettes including eight scenarios of test results with and without an emphasis on the risk of a current or future health condition or a probe to seek help. Participants rated perceived risk and willingness to seek help (0-100 Visual Analogue Scale) as if these were their own results. Differences were tested with paired-sample t-tests. In scenarios emphasizing the risk of a current or future disorder, participants perceived higher risk and were more willing to seek help (p-values < .00). Slightly higher willingness to seek help scores was observed in all scenarios that included probes (p < .00). Risk perception and willingness to seek help of workers participating in a preventive medical examination were higher when they were told that the test results indicate a risk of a current or future disorder and after being advised to seek help. Healthcare providers should take the potential effects on risk perception and help-seeking into account in preventive settings. Copyright © 2018. Published by Elsevier B.V.

Development, current applications and future roles of biorelevant two-stage in vitro testing in drug development.

PubMed

Fiolka, Tom; Dressman, Jennifer

2018-03-01

Various types of two stage in vitro testing have been used in a number of experimental settings. In addition to its application in quality control and for regulatory purposes, two-stage in vitro testing has also been shown to be a valuable technique to evaluate the supersaturation and precipitation behavior of poorly soluble drugs during drug development. The so-called 'transfer model', which is an example of two-stage testing, has provided valuable information about the in vivo performance of poorly soluble, weakly basic drugs by simulating the gastrointestinal drug transit from the stomach into the small intestine with a peristaltic pump. The evolution of the transfer model has resulted in various modifications of the experimental model set-up. Concomitantly, various research groups have developed simplified approaches to two-stage testing to investigate the supersaturation and precipitation behavior of weakly basic drugs without the necessity of using a transfer pump. Given the diversity among the various two-stage test methods available today, a more harmonized approach needs to be taken to optimize the use of two stage testing at different stages of drug development. © 2018 Royal Pharmaceutical Society.

The trauma film paradigm as an experimental psychopathology model of psychological trauma: intrusive memories and beyond.

PubMed

James, Ella L; Lau-Zhu, Alex; Clark, Ian A; Visser, Renée M; Hagenaars, Muriel A; Holmes, Emily A

2016-07-01

A better understanding of psychological trauma is fundamental to clinical psychology. Following traumatic event(s), a clinically significant number of people develop symptoms, including those of Acute Stress Disorder and/or Post Traumatic Stress Disorder. The trauma film paradigm offers an experimental psychopathology model to study both exposure and reactions to psychological trauma, including the hallmark symptom of intrusive memories. We reviewed 74 articles that have used this paradigm since the earliest review (Holmes & Bourne, 2008) until July 2014. Highlighting the different stages of trauma processing, i.e. pre-, peri- and post-trauma, the studies are divided according to manipulations before, during and after film viewing, for experimental as well as correlational designs. While the majority of studies focussed on the frequency of intrusive memories, other reactions to trauma were also modelled. We discuss the strengths and weaknesses of the trauma film paradigm as an experimental psychopathology model of trauma, consider ethical issues, and suggest future directions. By understanding the basic mechanisms underlying trauma symptom development, we can begin to translate findings from the laboratory to the clinic, test innovative science-driven interventions, and in the future reduce the debilitating effects of psychopathology following stressful and/or traumatic events. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Secondary light-ion transport from intermediate-energy hadron experiments

NASA Astrophysics Data System (ADS)

Srikrishna, Ashwin P.; Castellanos, Luis A.; McGirl, Natalie A.; Heilbronn, Lawrence H.; Tessas, Chiara La; Rusek, Adam; Sivertz, Michael; Blattnig, Steve; Clowdsley, Martha; Slaba, Tony; Zeitlin, Cary

2017-09-01

The aim of this research is to produce double differential thick target yields, angular distributions and integrated yields for the inclusive production of neutrons, protons, deuterons, tritons, 3He, and 4He from intermediate heavy-ion interactions on thick targets of aluminium, polyethylene and other targets of interest to the radiation shielding program as specified by the National Aeronautics and Space Administration (NASA). In tandem with the experimental research, transport model calculations of these thick target yields were also performed. The first such experimental run was conducted in May 2015, with the expectation of improved experimental results at a following March 2016 run at the NASA Space Radiation Laboratory (NSRL) on the campus of Brookhaven National Laboratory (BNL). The May 2015 commissioning run served to test the electronics of the experimental setup, as well as the various detectors and other equipment under the conditions in which the following measurements will be run. The series of future accelerator-based experiments will rely on the inclusion of two separate upstream and downstream targets. Analysis of the data from both sets of detectors - liquid scintillator and sodium iodide - using both pulse height and time-of-flight methods will allow NASA to perform uncertainty quantification and sensitivity analysis on their transport codes and future shielding studies.

The LArIAT experiment: first measurement of the inclusive total pion cross-section in Argon

NASA Astrophysics Data System (ADS)

de María Blaszczyk, Flor

2018-05-01

In light of future large neutrino experiments such as DUNE, an excellent understanding of LArTPCs is required. The Liquid Argon In A Test-beam (LArIAT) experiment, located in the Fermilab Test Beam Facility, is designed to characterize the performance of LArTPCs and improve the reconstruction algorithms but also to measure the cross-sections of charged particles in Argon. The goals and experimental layout will be presented, as well as the world’s first inclusive total pion interaction cross-section on Argon measured by LArIAT.

Experimental Optimization Methods for Multi-Element Airfoils

NASA Technical Reports Server (NTRS)

Landman, Drew; Britcher, Colin P.

1996-01-01

A modern three element airfoil model with a remotely activated flap was used to investigate optimum flap testing position using an automated optimization algorithm in wind tunnel tests. Detailed results for lift coefficient versus flap vertical and horizontal position are presented for two angles of attack: 8 and 14 degrees. An on-line first order optimizer is demonstrated which automatically seeks the optimum lift as a function of flap position. Future work with off-line optimization techniques is introduced and aerodynamic hysteresis effects due to flap movement with flow on are discussed.

Conical Probe Calibration and Wind Tunnel Data Analysis of the Channeled Centerbody Inlet Experiment

NASA Technical Reports Server (NTRS)

Truong, Samson Siu

2011-01-01

For a multi-hole test probe undergoing wind tunnel tests, the resulting data needs to be analyzed for any significant trends. These trends include relating the pressure distributions, the geometric orientation, and the local velocity vector to one another. However, experimental runs always involve some sort of error. As a result, a calibration procedure is required to compensate for this error. For this case, it is the misalignment bias angles resulting from the distortion associated with the angularity of the test probe or the local velocity vector. Through a series of calibration steps presented here, the angular biases are determined and removed from the data sets. By removing the misalignment, smoother pressure distributions contribute to more accurate experimental results, which in turn could be then compared to theoretical and actual in-flight results to derive any similarities. Error analyses will also be performed to verify the accuracy of the calibration error reduction. The resulting calibrated data will be implemented into an in-flight RTF script that will output critical flight parameters during future CCIE experimental test runs. All of these tasks are associated with and in contribution to NASA Dryden Flight Research Center s F-15B Research Testbed s Small Business Innovation Research of the Channeled Centerbody Inlet Experiment.

Using experimental data to test and improve SUSY theories

NASA Astrophysics Data System (ADS)

Wang, Ting

There are several pieces of evidence that our world is described by a supersymmetric extension of the Standard Model. In this thesis, I assume this is the case and study how to use experimental data to test and improve supersymmetric standard models. Several experimental signatures and their implications are covered in this thesis: the result of the branching ratio of b → sgamma is used to put constraints on SUSY models; the measured time-dependent CP asymmetry in the B → φKS process is used to test unification scale models; the excess of positrons from cosmic rays helps us to test the property of the Lightest Supersymmetric Particle and the Cold Dark Matter production mechanisms; the LEP higgs search results are used to classify SUSY models; SUSY signatures at the Tevatron are used to distinguish different unification scale models; by considering the mu problem, SUSY theories are improved. Due to the large unknown parameter space, all of the above inputs should be used to partially reconstruct the soft Lagrangian, which is the central part of the model. Combining the results from these analysis, a significant amount of knowledge about the underlying theory has been learned. In the next several years, there will be more data coming. The methods and results in this thesis will be useful for dealing with future data.

Assessment of needs for satellite tracking of birds and suggestions for expediting a program. [experimental design using Nimbus 6

NASA Technical Reports Server (NTRS)

Craighead, F. C., Jr.

1978-01-01

Equipment development and testing, animal-instrument interphase or attachment methods, and the evaluation of various feasibility-tracking experiments with raptors are described as well as suggestions for expediting a future program. Results of animal-instrument interphases work indicate that large free-flying birds can be successfully instrumented with radio packages comparable in weight to satellite-transmitter packages. The 401 MHz frequency proved satisfactory for a combination of satellite and ground tracking of migrating birds. Tests run for nearly a year with the Nimbus 6 satellite and a miniaturized, one-watt prototype RAMS transmitter produced encouraging results in regard to location accuracy, frequency of contact with satellite and use of whip antennas. A future program is recommended with priority given to development of six operational transmitters for feasibility experiments.

A Measurement Plane for Optical Networks to Manage Emergency Events

NASA Astrophysics Data System (ADS)

Tego, E.; Carciofi, C.; Grazioso, P.; Petrini, V.; Pompei, S.; Matera, F.; Attanasio, V.; Nastri, E.; Restuccia, E.

2017-11-01

In this work, we show a wide geographical area optical network test bed, adopting the mPlane measurement plane for monitoring its performance and to manage software defined network approaches, with some specific tests and procedures dedicated to respond to disaster events and to support emergency networks. Such a test bed includes FTTX accesses, and it is currently implemented to support future 5G wireless services with slicing procedures based on Carrier Ethernet. The characteristics of this platform have been experimentally tested in the case of a damage-causing link failure and traffic congestion, showing a fast reactions to these disastrous events, allowing the user to recharge the initial QoS parameters.

Testing the responses of four wheat crop models to heat stress at anthesis and grain filling.

PubMed

Liu, Bing; Asseng, Senthold; Liu, Leilei; Tang, Liang; Cao, Weixing; Zhu, Yan

2016-05-01

Higher temperatures caused by future climate change will bring more frequent heat stress events and pose an increasing risk to global wheat production. Crop models have been widely used to simulate future crop productivity but are rarely tested with observed heat stress experimental datasets. Four wheat models (DSSAT-CERES-Wheat, DSSAT-Nwheat, APSIM-Wheat, and WheatGrow) were evaluated with 4 years of environment-controlled phytotron experimental datasets with two wheat cultivars under heat stress at anthesis and grain filling stages. Heat stress at anthesis reduced observed grain numbers per unit area and individual grain size, while heat stress during grain filling mainly decreased the size of the individual grains. The observed impact of heat stress on grain filling duration, total aboveground biomass, grain yield, and grain protein concentration (GPC) varied depending on cultivar and accumulated heat stress. For every unit increase of heat degree days (HDD, degree days over 30 °C), grain filling duration was reduced by 0.30-0.60%, total aboveground biomass was reduced by 0.37-0.43%, and grain yield was reduced by 1.0-1.6%, but GPC was increased by 0.50% for cv Yangmai16 and 0.80% for cv Xumai30. The tested crop simulation models could reproduce some of the observed reductions in grain filling duration, final total aboveground biomass, and grain yield, as well as the observed increase in GPC due to heat stress. Most of the crop models tended to reproduce heat stress impacts better during grain filling than at anthesis. Some of the tested models require improvements in the response to heat stress during grain filling, but all models need improvements in simulating heat stress effects on grain set during anthesis. The observed significant genetic variability in the response of wheat to heat stress needs to be considered through cultivar parameters in future simulation studies. © 2016 John Wiley & Sons Ltd.

Measurement of fracture properties of concrete at high strain rates

PubMed Central

Cendón, D. A.; Sánchez-Gálvez, V.; Gálvez, F.

2017-01-01

An analysis of the spalling technique of concrete bars using the modified Hopkinson bar was carried out. A new experimental configuration is proposed adding some variations to previous works. An increased length for concrete specimens was chosen and finite-element analysis was used for designing a conic projectile to obtain a suitable triangular impulse wave. The aim of this initial work is to establish an experimental framework which allows a simple and direct analysis of concrete subjected to high strain rates. The efforts and configuration of these primary tests, as well as the selected geometry and dimensions for the different elements, have been focused to achieve a simple way of identifying the fracture position and so the tensile strength of tested specimens. This dynamic tensile strength can be easily compared with previous values published in literature giving an idea of the accuracy of the method and technique proposed and the possibility to extend it in a near future to obtain other mechanical properties such as the fracture energy. The tests were instrumented with strain gauges, accelerometers and high-speed camera in order to validate the results by different ways. Results of the dynamic tensile strength of the tested concrete are presented. This article is part of the themed issue ‘Experimental testing and modelling of brittle materials at high strain rates’. PMID:27956510

Implants in bone: part II. Research on implant osseointegration: material testing, mechanical testing, imaging and histoanalytical methods.

PubMed

von Wilmowsky, Cornelius; Moest, Tobias; Nkenke, Emeka; Stelzle, Florian; Schlegel, Karl Andreas

2014-12-01

In order to determine whether a newly developed implant material conforms to the requirements of biocompatibility, it must undergo rigorous testing. To correctly interpret the results of studies on implant material osseointegration, it is necessary to have a sound understanding of all the testing methods. The aim of this overview is to elucidate the methods that are used for the experimental evaluation of the osseointegration of implant materials. In recent decades, there has been a constant proliferation of new materials and surface modifications in the field of dental implants. This continuous development of innovative biomaterials requires a precise and detailed evaluation in terms of biocompatibility and implant healing before clinical use. The current gold standard is in vivo animal testing on well validated animal models. However, long-term outcome studies on patients have to follow to finally validate and show patient benefit. No experimental set-up can provide answers for all possible research questions. However, a certain transferability of the results to humans might be possible if the experimental set-up is carefully chosen for the aspects and questions being investigated. To enhance the implant survival rate in the rising number of patients with chronic diseases which compromise wound healing and osseointegration, dental implant research on compromised animal models will further gain importance in future.

Study and design of cryogenic propellant acquisition systems. Volume 2: Supporting experimental program

NASA Technical Reports Server (NTRS)

Burge, G. W.; Blackmon, J. B.

1973-01-01

Areas of cryogenic fuel systems were identified where critical experimental information was needed either to define a design criteria or to establish the feasibility of a design concept or a critical aspect of a particular design. Such data requirements fell into three broad categories: (1) basic surface tension screen characteristics; (2) screen acquisition device fabrication problems; and (3) screen surface tension device operational failure modes. To explore these problems and to establish design criteria where possible, extensive laboratory or bench test scale experiments were conducted. In general, these proved to be quite successful and, in many instances, the test results were directly used in the system design analyses and development. In some cases, particularly those relating to operational-type problems, areas requiring future research were identified, especially screen heat transfer and vibrational effects.

Assessment of JVX Proprotor Performance Data in Hover and Airplane-Mode Flight Conditions

NASA Technical Reports Server (NTRS)

Acree, C. W., Jr.

2016-01-01

A 0.656-scale V-22 proprotor, the Joint Vertical Experimental (JVX) rotor, was tested at the NASA Ames Research Center in both hover and airplane-mode (high-speed axial flow) flight conditions, up to an advance ratio of 0.562 (231 knots). This paper examines the two principal data sets generated by those tests, and includes investigations of hub spinner tares, torque/thrust measurement interactions, tunnel blockage effects, and other phenomena suspected of causing erroneous measurements or predictions. Uncertainties in hover and high-speed data are characterized. The results are reported here to provide guidance for future wind tunnel tests, data processing, and data analysis.

Biosphere 2 test module experimentation program

NASA Technical Reports Server (NTRS)

Alling, Abigail; Leigh, Linda S.; Maccallum, Taber; Alvarez-Romo, Norberto

1990-01-01

The Biosphere 2 Test Module is a facility which has the capability to do either short or long term closures: five month closures with plants were conducted. Also conducted were investigations of specific problems, such as trace gas purification by bioregenerative systems by in-putting a fixed concentration of a gas and observing its uptake over time. In other Test Module experiments, the concentration of one gas was changed to observe what effects this has on other gases present or on the system. The science of biospherics which encompasses the study of closed biological systems provides an opening into the future in space as well as in the Earth's biosphere.

Development of an integrated set of research facilities for the support of research flight test

NASA Technical Reports Server (NTRS)

Moore, Archie L.; Harney, Constance D.

1988-01-01

The Ames-Dryden Flight Research Facility (DFRF) serves as the site for high-risk flight research on many one-of-a-kind test vehicles like the X-29A advanced technology demonstrator, F-16 advanced fighter technology integration (AFTI), AFTI F-111 mission adaptive wing, and F-18 high-alpha research vehicle (HARV). Ames-Dryden is on a section of the historic Muroc Range. The facility is oriented toward the testing of high-performance aircraft, as shown by its part in the development of the X-series aircraft. Given the cost of research flight tests and the complexity of today's systems-driven aircraft, an integrated set of ground support experimental facilities is a necessity. In support of the research flight test of highly advanced test beds, the DFRF is developing a network of facilities to expedite the acquisition and distribution of flight research data to the researcher. The network consists of an array of experimental ground-based facilities and systems as nodes and the necessary telecommunications paths to pass research data and information between these facilities. This paper presents the status of the current network, an overview of current developments, and a prospectus on future major enhancements.

Plans for an ERL Test Facility at CERN

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

Jensen, Erik; Bruning, O S; Calaga, Buchi Rama Rao

2014-12-01

The baseline electron accelerator for LHeC and one option for FCC-he is an Energy Recovery Linac. To prepare and study the necessary key technologies, CERNhas started – in collaboration with JLAB and Mainz University – the conceptual design of an ERL Test Facility (ERL-TF). Staged construction will allow the study under different conditions with up to 3 passes, beam energies of up to about 1 GeV and currents of up to 50 mA. The design and development of superconducting cavity modules, including coupler and HOM damper designs, are also of central importance for other existing and future accelerators and theirmore » tests are at the heart of the current ERL-TF goals. However, the ERL-TF could also provide a unique infrastructure for several applications that go beyond developing and testing the ERL technology at CERN. In addition to experimental studies of beam dynamics, operational and reliability issues in an ERL, it could equally serve for quench tests of superconducting magnets, as physics experimental facility on its own right or as test stand for detector developments. This contribution will describe the goals and the concept of the facility and the status of the R&D.« less

Effect of STS space suit on astronaut dominant upper limb EVA work performance

NASA Technical Reports Server (NTRS)

Greenisen, Michael C.

1987-01-01

The STS Space Suited and unsuited dominant upper limb performance was evaluated in order to quantify future EVA astronaut skeletal muscle upper limb performance expectations. Testing was performed with subjects standing in EVA STS foot restraints. Data was collected with a CYBEX Dynamometer enclosed in a waterproof container. Control data was taken in one g. During one g testing, weight of the Space Suit was relieved from the subject via an overhead crane with a special connection to the PLSS of the suit. Experimental data was acquired during simulated zero g, accomplished by neutral buoyancy in the Weightless Environment Training Facility. Unsuited subjects became neutrally buoyant via SCUBA BC vests. Actual zero g experimental data was collected during parabolic arc flights on board NASA's modified KC-135 aircraft. During all test conditions, subjects performed five EVA work tasks requiring dominant upper limb performance and ten individual joint articulation movements. Dynamometer velocities for each tested movement were 0 deg/sec, 30 or 60 deg/sec and 120 or 180 deg/sec, depending on the test, with three repetitions per test. Performance was measured in foot pounds of torque.

Alternatives to animal testing: current status and future perspectives.

PubMed

Liebsch, Manfred; Grune, Barbara; Seiler, Andrea; Butzke, Daniel; Oelgeschläger, Michael; Pirow, Ralph; Adler, Sarah; Riebeling, Christian; Luch, Andreas

2011-08-01

On the occasion of the 20th anniversary of the Center for Alternative Methods to Animal Experiments (ZEBET), an international symposium was held at the German Federal Institute for Risk Assessment (BfR) in Berlin. At the same time, this symposium was meant to celebrate the 50th anniversary of the publication of the book "The Principles of Humane Experimental Technique" by Russell and Burch in 1959 in which the 3Rs principle (that is, Replacement, Reduction, and Refinement) has been coined and introduced to foster the development of alternative methods to animal testing. Another topic addressed by the symposium was the new vision on "Toxicology in the twenty-first Century", as proposed by the US-National Research Council, which aims at using human cells and tissues for toxicity testing in vitro rather than live animals. An overview of the achievements and current tasks, as well as a vision of the future to be addressed by ZEBET@BfR in the years to come is outlined in the present paper.

Advanced mobile satellite communications using COMETS satellite in MM-wave and Ka-band

NASA Technical Reports Server (NTRS)

Ohmori, Shingo; Isobe, Shunkichi; Takeuchi, Makoto; Naito, Hideyuki

1993-01-01

Early in the 21st century, the demand for personal communications using mobile, hand-held, and VSAT terminals will rapidly increase. In a future system, many different types of services should be provided with one-hop connection. The Communications Research Laboratory (CRL) has studied a future advanced mobile satellite communications system using millimeter wave and Ka band. In 1990, CRL started the Communications and Broadcasting Engineering Test Satellite (COMETS) project. The satellite has been developed in conjunction with NASDA and will be launched in 1997. This paper describes the COMETS payload configuration and the experimental system for the advanced mobile communications mission.

Active vibration control activities at the LaRC - Present and future

NASA Technical Reports Server (NTRS)

Newsom, J. R.

1990-01-01

The NASA Controls-Structures-Interaction (CSI) program is presented with a description of the ground testing element objectives and approach. The goal of the CSI program is to develop and validate the technology required to design, verify and operate space systems in which the structure and the controls interact beneficially to meet the needs of future NASA missions. The operational Mini-Mast ground testbed and some sample active vibration control experimental results are discussed along with a description of the CSI Evolutionary Model testbed presently under development. Initial results indicate that embedded sensors and actuators are effective in controlling a large truss/reflector structure.

State of the art on alternative methods to animal testing from an industrial point of view: ready for regulation?

PubMed

Ashton, Rachel; De Wever, Bart; Fuchs, Horst W; Gaca, Marianna; Hill, Erin; Krul, Cyrille; Poth, Albrecht; Roggen, Erwin L

2014-01-01

Despite changing attitudes towards animal testing and current legislation to protect experimental animals, the rate of animal experiments seems to have changed little in recent years. On May 15-16, 2013, the In Vitro Testing Industrial Platform (IVTIP) held an open meeting to discuss the state of the art in alternative methods, how companies have, can, and will need to adapt and what drives and hinders regulatory acceptance and use. Several key messages arose from the meeting. First, industry and regulatory bodies should not wait for complete suites of alternative tests to become available, but should begin working with methods available right now (e.g., mining of existing animal data to direct future studies, implementation of alternative tests wherever scientifically valid rather than continuing to rely on animal tests) in non-animal and animal integrated strategies to reduce the numbers of animals tested. Sharing of information (communication), harmonization and standardization (coordination), commitment and collaboration are all required to improve the quality and speed of validation, acceptance, and implementation of tests. Finally, we consider how alternative methods can be used in research and development before formal implementation in regulations. Here we present the conclusions on what can be done already and suggest some solutions and strategies for the future.

Application of historical mobility testing to sensor-based robotic performance

NASA Astrophysics Data System (ADS)

Willoughby, William E.; Jones, Randolph A.; Mason, George L.; Shoop, Sally A.; Lever, James H.

2006-05-01

The USA Engineer Research and Development Center (ERDC) has conducted on-/off-road experimental field testing with full-sized and scale-model military vehicles for more than fifty years. Some 4000 acres of local terrain are available for tailored field evaluations or verification/validation of future robotic designs in a variety of climatic regimes. Field testing and data collection procedures, as well as techniques for quantifying terrain in engineering terms, have been developed and refined into algorithms and models for predicting vehicle-terrain interactions and resulting forces or speeds of military-sized vehicles. Based on recent experiments with Matilda, Talon, and Pacbot, these predictive capabilities appear to be relevant to most robotic systems currently in development. Utilization of current testing capabilities with sensor-based vehicle drivers, or use of the procedures for terrain quantification from sensor data, would immediately apply some fifty years of historical knowledge to the development, refinement, and implementation of future robotic systems. Additionally, translation of sensor-collected terrain data into engineering terms would allow assessment of robotic performance a priori deployment of the actual system and ensure maximum system performance in the theater of operation.

The end is (not) near: Aging, essentialism, and future time perspective.

PubMed

Weiss, David; Job, Veronika; Mathias, Maya; Grah, Stephanie; Freund, Alexandra M

2016-06-01

Beliefs about aging influence how we interpret and respond to changes within and around us. Essentialist beliefs about aging are defined as views that link chronological age with inherent and immutable properties underlying aging-related changes. These beliefs may influence the experience of aging-related changes and shape people's outlook of the future. We hypothesized that people who endorse essentialist beliefs about aging report a more limited future time perspective. Two studies provided correlational (Study 1, N = 250; 18-77 years) and experimental (Study 2, N = 103; 20-77 years) evidence that essentialist beliefs about aging affect people's future time perspective. In addition, Study 2 and Study 3 (N = 174; 34-67 years) tested the underlying mechanism and provided evidence that perception of aging-related threat explains the effect of essentialist beliefs on a reduced future time perspective. These findings highlight the fundamental role of essentialist beliefs about aging for the perception of time horizons in the context of aging. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Using Numerical Modeling to Simulate Space Capsule Ground Landings

NASA Technical Reports Server (NTRS)

Heymsfield, Ernie; Fasanella, Edwin L.

2009-01-01

Experimental work is being conducted at the National Aeronautics and Space Administration s (NASA) Langley Research Center (LaRC) to investigate ground landing capabilities of the Orion crew exploration vehicle (CEV). The Orion capsule is NASA s replacement for the Space Shuttle. The Orion capsule will service the International Space Station and be used for future space missions to the Moon and to Mars. To evaluate the feasibility of Orion ground landings, a series of capsule impact tests are being performed at the NASA Langley Landing and Impact Research Facility (LandIR). The experimental results derived at LandIR provide means to validate and calibrate nonlinear dynamic finite element models, which are also being developed during this study. Because of the high cost and time involvement intrinsic to full-scale testing, numerical simulations are favored over experimental work. Subsequent to a numerical model validated by actual test responses, impact simulations will be conducted to study multiple impact scenarios not practical to test. Twenty-one swing tests using the LandIR gantry were conducted during the June 07 through October 07 time period to evaluate the Orion s impact response. Results for two capsule initial pitch angles, 0deg and -15deg , along with their computer simulations using LS-DYNA are presented in this article. A soil-vehicle friction coefficient of 0.45 was determined by comparing the test stopping distance with computer simulations. In addition, soil modeling accuracy is presented by comparing vertical penetrometer impact tests with computer simulations for the soil model used during the swing tests.

Experimental testing and numerical simulation on natural composite for aerospace applications

NASA Astrophysics Data System (ADS)

Kumar, G. Raj; Vijayanandh, R.; Kumar, M. Senthil; Kumar, S. Sathish

2018-05-01

Nowadays polymers are commonly used in various applications, which make it difficult to avoid its usage even though it causes environmental problems. Natural fibers are best alternate to overcome the polymer based environmental issues. Natural fibers play an important role in developing high performing fully newline biodegradable green composites which will be a key material to solve environmental problems in future. In this paper deals the properties analysis of banana fiber is combined with epoxy resin in order to create a natural composite, which has special characteristics for aerospace applications. The objective of this paper is to investigate the characteristics of failure modes and strength of natural composite using experimental and numerical methods. The test specimen of natural composite has been fabricated as per ASTM standard, which undergoes tensile and compression tests using Tinius Olsen UTM in order to determine mechanical and physical properties. The reference model has been designed by CATIA, and then numerical simulation has been carried out by Ansys Workbench 16.2 for the given boundary conditions.

Experimental Results for Titan Aerobot Thermo-Mechanical Subsystem Development

NASA Technical Reports Server (NTRS)

Hall, Jeffrey L.; Jones, J. A.; Kerzhanovich, V. V.; Lachenmeier, T.; Mahr, P.; Pauken, M.; Plett, G. A.; Smith, L.; VanLuvender, M. L.; Yavrouian, A. H.

2006-01-01

This paper describes experimental results from a development program focused in maturing Titan aerobot technology in the areas of mechanical and thermal subsystems. Results from four key activities are described: first, a cryogenic balloon materials development program involving coupon and cylinder tests and culminating in the fabrication and testing of an inflated 4.6 m long prototype blimp at 93 K; second, a combined lab experiment and numerical simulation effort to assess potential problems resulting from radioisotope thermal generator waste heat generation near an inflated blimp; third, an aerial deployment and inflation development program consisting of laboratory and helicopter drop tests on a near full scale (11 m long) prototype blimp; and fourth, a proof of concept experiment demonstrating the viability of using a mechanically steerable high gain antenna on a floating blimp to perform direct to Earth telecommunications from Titan. The paper provides details on all of these successful activities and discusses their impact on the overall effort to produce mature systems technology for future Titan aerobot missions.

Performance Gains of Propellant Management Devices for Liquid Hydrogen Depots

NASA Technical Reports Server (NTRS)

Hartwig, Jason W.; McQuillen, John B.; Chato, David J.

2013-01-01

This paper presents background, experimental design, and preliminary experimental results for the liquid hydrogen bubble point tests conducted at the Cryogenic Components Cell 7 facility at the NASA Glenn Research Center in Cleveland, Ohio. The purpose of the test series was to investigate the parameters that affect liquid acquisition device (LAD) performance in a liquid hydrogen (LH2) propellant tank, to mitigate risk in the final design of the LAD for the Cryogenic Propellant Storage and Transfer Technology Demonstration Mission, and to provide insight into optimal LAD operation for future LH2 depots. Preliminary test results show an increase in performance and screen retention over the low reference LH2 bubble point value for a 325 2300 screen in three separate ways, thus improving fundamental LH2 LAD performance. By using a finer mesh screen, operating at a colder liquid temperature, and pressurizing with a noncondensible pressurant gas, a significant increase in margin is achieved in bubble point pressure for LH2 screen channel LADs.

Evaluation of boron-epoxy-reinforced titanium tubular truss for application to a space shuttle booster thrust structure

NASA Technical Reports Server (NTRS)

Corvelli, N.; Carri, R.

1972-01-01

Results of a study to demonstrate the applicability of boron-epoxy-composite-reinforced titanium tubular members to a space shuttle booster thrust structure are presented and discussed. The experimental results include local buckling of all-composite and composite-reinforced-metal cylinders with low values of diameter-thickness ratio, static tests on composite-to-metal bonded step joints, and a test to failure of a boron-epoxy-reinforced titanium demonstration truss. The demonstration truss failed at 118 percent of design ultimate load. Test results and analysis for all specimens and the truss are compared. Comparing an all-titanium design and a boron-epoxy-reinforced-titanium (75 percent B-E and 25 percent Ti) design for application to the space shuttle booster thrust structure indicates that the latter would weigh approximately 24 percent less. Experimental data on the local buckling strength of cylinders with a diameter-thickness ratio of approximately 50 are needed to insure that undue conservatism is not used in future designs.

Experimental investigation of a 2.5 centimeter diameter Kaufman microthruster

NASA Technical Reports Server (NTRS)

Cohen, A. J.

1973-01-01

A 2.5-centimeter-diameter Kaufman electron bombardment microthruster was fabricated and tested. The microthruster design was based on the 15-centimeter-diameter SERT 2 and 5-centimeter-diameter Lewis experimental thruster designs. The microthruster with a two-grid system, operating at a net accelerating potential of 600 volts and an accelerator potential of 500 volts, produced a calculated 445 micronewton thrust when it was run with a 9-milliampere beam current. A glass grid was initially used in testing. Later a two-grid system was successfully incorporated. Both the propellant utilization efficiency and the total power efficiency were lower than for large-size advanced thrusters, as expected; but they were sufficiently high that 2.5-centimeter thrusters show promise for future space applications. Total power of the microthruster with an assumed 7-watt hollow-cathode neutralizer was less than 30 watts at a thrust level of 445 micronewton (100 Nu LBf). The hollow cathode was operated at zero tip heater power for power requirement tests.

Pilot study on infant swimming classes and early motor development.

PubMed

Dias, Jorge A B de S; Manoel, Edison de J; Dias, Roberta B de M; Okazaki, Victor H A

2013-12-01

Alberta Infant Motor Scale (AIMS) scores were examined before and after four months of swimming classes in 12 babies (ages 7 to 9 mo.) assigned to Experimental (n = 6) and Control (n = 6) groups matched on age and developmental status. Infants from both groups improved their developmental status from pre- to post-test; the Experimental group improved on mean percentile rank. The sample size and the discriminative power of the AIMS do not allow conclusive judgments on these group differences, hence on the effect of infant swimming classes. Nevertheless, a number of recommendations are made for future studies on the effect of swimming classes on infant motor development.

Experimental verification of PSM polarimetry: monitoring polarization at 193nm high-NA with phase shift masks

NASA Astrophysics Data System (ADS)

McIntyre, Gregory; Neureuther, Andrew; Slonaker, Steve; Vellanki, Venu; Reynolds, Patrick

2006-03-01

The initial experimental verification of a polarization monitoring technique is presented. A series of phase shifting mask patterns produce polarization dependent signals in photoresist and are capable of monitoring the Stokes parameters of any arbitrary illumination scheme. Experiments on two test reticles have been conducted. The first reticle consisted of a series of radial phase gratings (RPG) and employed special apertures to select particular illumination angles. Measurement sensitivities of about 0.3 percent of the clear field per percent change in polarization state were observed. The second test reticle employed the more sensitive proximity effect polarization analyzers (PEPA), a more robust experimental setup, and a backside pinhole layer for illumination angle selection and to enable characterization of the full illuminator. Despite an initial complication with the backside pinhole alignment, the results correlate with theory. Theory suggests that, once the pinhole alignment is corrected in the near future, the second reticle should achieve a measurement sensitivity of about 1 percent of the clear field per percent change in polarization state. This corresponds to a measurement of the Stokes parameters after test mask calibration, to within about 0.02 to 0.03. Various potential improvements to the design, fabrication of the mask, and experimental setup are discussed. Additionally, to decrease measurement time, a design modification and double exposure technique is proposed to enable electrical detection of the measurement signal.

The need for precise and well-documented experimental data on prompt fission neutron spectra from neutron-induced fission of 239Pu

DOE PAGES

Neudecker, Denise; Taddeucci, Terry Nicholas; Haight, Robert Cameron; ...

2016-01-06

The spectrum of neutrons emitted promptly after 239Pu(n,f)—a so-called prompt fission neutron spectrum (PFNS)—is a quantity of high interest, for instance, for reactor physics and global security. However, there are only few experimental data sets available that are suitable for evaluations. In addition, some of those data sets differ by more than their 1-σ uncertainty boundaries. We present the results of MCNP studies indicating that these differences are partly caused by underestimated multiple scattering contributions, over-corrected background, and inconsistent deconvolution methods. A detailed uncertainty quantification for suitable experimental data was undertaken including these effects, and test-evaluations were performed with themore » improved uncertainty information. The test-evaluations illustrate that the inadequately estimated effects and detailed uncertainty quantification have an impact on the evaluated PFNS and associated uncertainties as well as the neutron multiplicity of selected critical assemblies. A summary of data and documentation needs to improve the quality of the experimental database is provided based on the results of simulations and test-evaluations. Furthermore, given the possibly substantial distortion of the PFNS by multiple scattering and background effects, special care should be taken to reduce these effects in future measurements, e.g., by measuring the 239Pu PFNS as a ratio to either the 235U or 252Cf PFNS.« less

NUCLEAR AND HEAVY ION PHYSICS: α-decay half-lives of superheavy nuclei and general predictions

NASA Astrophysics Data System (ADS)

Dong, Jian-Min; Zhang, Hong-Fei; Wang, Yan-Zhao; Zuo, Wei; Su, Xin-Ning; Li, Jun-Qing

2009-08-01

The generalized liquid drop model (GLDM) and the cluster model have been employed to calculate the α-decay half-lives of superheavy nuclei (SHN) using the experimental α-decay Q values. The results of the cluster model are slightly poorer than those from the GLDM if experimental Q values are used. The prediction powers of these two models with theoretical Q values from Audi et al. (QAudi) and Muntian et al. (QM) have been tested to find that the cluster model with QAudi and QM could provide reliable results for Z > 112 but the GLDM with QAudi for Z <= 112. The half-lives of some still unknown nuclei are predicted by these two models and these results may be useful for future experimental assignment and identification.

Probing leptogenesis

NASA Astrophysics Data System (ADS)

Chun, E. J.; Cvetič, G.; Dev, P. S. B.; Drewes, M.; Fong, C. S.; Garbrecht, B.; Hambye, T.; Harz, J.; Hernández, P.; Kim, C. S.; Molinaro, E.; Nardi, E.; Racker, J.; Rius, N.; Zamora-Saa, J.

2018-02-01

The focus of this paper lies on the possible experimental tests of leptogenesis scenarios. We consider both leptogenesis generated from oscillations, as well as leptogenesis from out-of-equilibrium decays. As the Akhmedov-Rubakov-Smirnov (ARS) mechanism allows for heavy neutrinos in the GeV range, this opens up a plethora of possible experimental tests, e.g. at neutrino oscillation experiments, neutrinoless double beta decay, and direct searches for neutral heavy leptons at future facilities. In contrast, testing leptogenesis from out-of-equilibrium decays is a quite difficult task. We comment on the necessary conditions for having successful leptogenesis at the TeV-scale. We further discuss possible realizations and their model specific testability in extended seesaw models, models with extended gauge sectors, and supersymmetric leptogenesis. Not being able to test high-scale leptogenesis directly, we present a way to falsify such scenarios by focusing on their washout processes. This is discussed specifically for the left-right symmetric model and the observation of a heavy WR, as well as model independently when measuring ΔL = 2 washout processes at the LHC or neutrinoless double beta decay.

Entry, Descent, and Landing with Propulsive Deceleration: Supersonic Retropropulsion Wind Tunnel Testing and Shock Phenomena

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan

2014-01-01

The future exploration of the Solar System will require innovations in transportation and the use of entry, descent, and landing (EDL) systems at many planetary landing sites. The cost of space missions has always been prohibitive, and using the natural planetary and planet's moon atmospheres for entry, and descent can reduce the cost, mass, and complexity of these missions. This paper will describe some of the EDL ideas for planetary entry and survey the overall technologies for EDL that may be attractive for future Solar System missions. Future EDL systems may include an inflatable decelerator for the initial atmospheric entry and an additional supersonic retropropulsion (SRP) rocket system for the final soft landing. A three engine retropropulsion configuration with a 2.5 in. diameter sphere-cone aeroshell model was tested in the NASA Glenn Research Center's 1- by 1-ft (1×1) Supersonic Wind Tunnel (SWT). The testing was conducted to identify potential blockage issues in the tunnel, and visualize the rocket flow and shock interactions during supersonic and hypersonic entry conditions. Earlier experimental testing of a 70deg Viking-like (sphere-cone) aeroshell was conducted as a baseline for testing of a SRP system. This baseline testing defined the flow field around the aeroshell and from this comparative baseline data, retropropulsion options will be assessed. Images and analyses from the SWT testing with 300- and 500-psia rocket engine chamber pressures are presented here. In addition, special topics of electromagnetic interference with retropropulsion induced shock waves and retropropulsion for Earth launched booster recovery are also addressed.

Entry, Descent, and Landing with Propulsive Deceleration: Supersonic Retropropulsion Wind Tunnel Testing and Shock Phenomena

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan

2013-01-01

The future exploration of the Solar System will require innovations in transportation and the use of entry, descent, and landing (EDL) systems at many planetary landing sites. The cost of space missions has always been prohibitive, and using the natural planetary and planet's moon atmospheres for entry, and descent can reduce the cost, mass, and complexity of these missions. This paper will describe some of the EDL ideas for planetary entry and survey the overall technologies for EDL that may be attractive for future Solar System missions. Future EDL systems may include an inflatable decelerator for the initial atmospheric entry and an additional supersonic retro-propulsion (SRP) rocket system for the final soft landing. A three engine retro-propulsion configuration with a 2.5 inch diameter sphere-cone aeroshell model was tested in the NASA Glenn 1x1 Supersonic Wind Tunnel (SWT). The testing was conducted to identify potential blockage issues in the tunnel, and visualize the rocket flow and shock interactions during supersonic and hypersonic entry conditions. Earlier experimental testing of a 70 degree Viking-like (sphere-cone) aeroshell was conducted as a baseline for testing of a supersonic retro-propulsion system. This baseline testing defined the flow field around the aeroshell and from this comparative baseline data, retro-propulsion options will be assessed. Images and analyses from the SWT testing with 300- and 500-psia rocket engine chamber pressures are presented here. In addition, special topics of electromagnetic interference with retro-propulsion induced shock waves and retro-propulsion for Earth launched booster recovery are also addressed.

Using memories to motivate future behaviour: an experimental exercise intervention.

PubMed

Biondolillo, Mathew J; Pillemer, David B

2015-01-01

This study tested a novel memory-based experimental intervention to increase exercise activity. Undergraduate students completed a two-part online survey ostensibly regarding college activity choices. At Time 1, they completed questionnaires that included assessments of exercise-related attitudes, motivation and self-reported behaviours. Next, they described a memory of a positive or negative experience that would increase their motivation to exercise; students in a control condition did not receive a memory prompt. Finally, they rated their intentions to exercise in the future. Eight days following Time 1, students received a Time 2 survey that included an assessment of their self-reported exercise during the prior week. Students in the positive memory condition reported higher levels of subsequent exercise than those in the control condition; students in the negative memory condition reported intermediate levels of exercise. Activating a positive motivational memory had a significant effect on students' self-reported exercise activity even after controlling for prior attitudes, motivation and exercise activity.

Structure–property characterization of the crinkle-leaf peach wood phenotype: a future model system for wood properties research?

Treesearch

Alex C. Wiedenhoeft; Rafael Arévalo; Craig Ledbetter; Joseph E. Jakes

2016-01-01

Nearly 400 million years of evolution and field-testing by the natural world has given humans thousands of wood types, each with unique structure– property relationships to study, exploit, and ideally, to manipulate, but the slow growth of trees makes them a recalcitrant experimental system. Variations in wood features of two genotypes of peach (Prunus persica L.)...

A survey of experiments and experimental facilities for control of flexible structures

NASA Technical Reports Server (NTRS)

Sparks, Dean W., Jr.; Juang, Jer-Nan; Klose, Gerhard J.

1989-01-01

This paper presents a survey of U.S. ground experiments and facilities dedicated to the study of active control of flexible structures. The facilities will be briefly described in terms of capability, configuration, size and instrumentation. Topics on the experiments include vibration suppression, slewing and system identification. Future research directions, particularly of the NASA Langley Research Center's Controls/Structures Interaction (CSI) ground test program, will be discussed.

Avalanche Photoconductive Switching

DTIC Science & Technology

1989-06-01

implantation and by MBE growth , and p-type material was created by MBE growth of a Be doped layer. Ion implantation creates a heavily doped layer...which is used commonly for GaAs integrated circuits. We plan to use Ti-Pt-Au for p-type contacts in the future. Experimental Results Test Confi...optical wavelenght does not significantly affect the switching process. Another feature of this mode of operation is that there is a threshold

Numerical Modeling of Propellant Boil-Off in a Cryogenic Storage Tank

NASA Technical Reports Server (NTRS)

Majumdar, A. K.; Steadman, T. E.; Maroney, J. L.; Sass, J. P.; Fesmire, J. E.

2007-01-01

A numerical model to predict boil-off of stored propellant in large spherical cryogenic tanks has been developed. Accurate prediction of tank boil-off rates for different thermal insulation systems was the goal of this collaboration effort. The Generalized Fluid System Simulation Program, integrating flow analysis and conjugate heat transfer for solving complex fluid system problems, was used to create the model. Calculation of tank boil-off rate requires simultaneous simulation of heat transfer processes among liquid propellant, vapor ullage space, and tank structure. The reference tank for the boil-off model was the 850,000 gallon liquid hydrogen tank at Launch Complex 39B (LC- 39B) at Kennedy Space Center, which is under study for future infrastructure improvements to support the Constellation program. The methodology employed in the numerical model was validated using a sub-scale model and tank. Experimental test data from a 1/15th scale version of the LC-39B tank using both liquid hydrogen and liquid nitrogen were used to anchor the analytical predictions of the sub-scale model. Favorable correlations between sub-scale model and experimental test data have provided confidence in full-scale tank boil-off predictions. These methods are now being used in the preliminary design for other cases including future launch vehicles

Using mental visual imagery to improve autobiographical memory and episodic future thinking in relapsing-remitting multiple sclerosis patients: A randomised-controlled trial study.

PubMed

Ernst, Alexandra; Blanc, Frédéric; De Seze, Jérôme; Manning, Liliann

2015-01-01

The co-occurrence of autobiographical memory (AM) and episodic future thinking (EFT) impairment has been documented in relapsing-remitting multiple sclerosis (RR-MS) patients. On these bases, we aimed at probing the efficacy of a mental visual imagery (MVI)-based facilitation programme on AM and EFT functioning in the context of a randomised-controlled trial study in RR-MS patients. Using the Autobiographical Interview (AI), 40 patients presenting with an AM/EFT impairment were randomly assigned in three groups: (i) the experimental (n = 17), who followed the MVI programme, (ii) the verbal control (n = 10), who followed a sham verbal programme, and (iii) the stability groups (n = 13), who underwent the AM/EFT test twice, with no intervention in between. AI's second assessment scores showed a significant improvement of AM and EFT performance only for the experimental group, with a long-term robustness of treatment benefits. The control and stability groups' results ruled out nursing and test learning effects as explanations of AM/EFT improvement. These benefits were corroborated by the patients' comments, which indicated an effective MVI strategy transfer to daily life. Our results suggest that the MVI programme tackles a common cognitive process of scene construction present in AM and EFT.

Hepatitis B ESL education for Asian immigrants.

PubMed

Taylor, Vicky M; Gregory Hislop, T; Bajdik, Christopher; Teh, Chong; Lam, Wendy; Acorda, Elizabeth; Li, Lin; Yasui, Yutaka

2011-02-01

Asian communities in North America include large numbers of immigrants with limited English proficiency. Hepatitis B virus (HBV) infection is endemic in most Asian countries and, therefore, Asian immigrant groups have high rates of chronic HBV infection. We conducted a group-randomized trial to evaluate the effectiveness of a hepatitis B English as a second language (ESL) educational curriculum for Asian immigrants. Eighty ESL classes were randomized to experimental (hepatitis B education) or control (physical activity education) status. Students who reported they had not received a HBV test (at baseline) completed a follow-up survey 6 months after randomization. The follow-up survey assessed recent HBV testing and HBV-related knowledge. Provider reports were used to verify self-reported HBV tests. The study group included 218 students who reported they had not been tested for HBV. Follow-up surveys were completed by 180 (83%) of these students. Provider records verified HBV testing for 6% of the experimental group students and 0% of the control group students (P = 0.02). Experimental group students were significantly (P < 0.05) more likely than control group students to know that immigrants have high HBV infection rates, HBV can be spread during sexual intercourse and by sharing razors, and HBV infection can cause liver cancer. Our ESL curriculum had a meaningful impact on HBV-related knowledge and a limited impact on HBV testing levels. Future research should evaluate the effectiveness of ESL curricula for other immigrant groups and other health topics, as well as other intervention approaches to increasing levels of HBV testing in Asian immigrant communities.

Hepatitis B ESL Education for Asian Immigrants

PubMed Central

Taylor, Vicky M.; Hislop, T. Gregory; Bajdik, Christopher; Teh, Chong; Lam, Wendy; Acorda, Elizabeth; Li, Lin; Yasui, Yutaka

2010-01-01

Objectives Asian communities in North America include large numbers of immigrants with limited English proficiency. Hepatitis B virus (HBV) infection is endemic in most Asian countries and, therefore, Asian immigrant groups have high rates of chronic HBV infection. We conducted a group-randomized trial to evaluate the effectiveness of a hepatitis B English as a second language (ESL) educational curriculum for Asian immigrants Methods Eighty ESL classes were randomized to experimental (hepatitis B education) or control (physical activity education) status. Students who reported they had not received a HBV test (at baseline) completed a follow-up survey six months after randomization. The follow-up survey assessed recent HBV testing and HBV-related knowledge. Provider reports were used to verify self-reported HBV tests. Results The study group included 218 students who reported they had not been tested for HBV. Follow-up surveys were completed by 180 (83%) of these students. Provider records verified HBV testing for 6% of the experimental group students and 0% of the control group students (p=0.02). Experimental group students were significantly (p<0.05) more likely than control group students to know that immigrants have high HBV infection rates, HBV can be spread during sexual intercourse and by sharing razors, and HBV infection can cause liver cancer. Conclusion Our ESL curriculum had a meaningful impact on HBV-related knowledge and a limited impact on HBV testing levels. Future research should evaluate the effectiveness of ESL curricula for other immigrant groups and other health topics, as well as other intervention approaches to increasing levels of HBV testing in Asian immigrant communities. PMID:20559696

Determination of Interlaminar Toughness of IM7/977-2 Composites at Temperature Extremes and Different Thicknesses

NASA Technical Reports Server (NTRS)

Johnson, W. S.; Pavlick, M. M.; Oliver, M. S.

2005-01-01

Composite materials are being used in the aerospace industry as a means of reducing vehicle weight. In particular, polymer matrix composites (PMC) are good candidates due to their high strength-to-weight and high stiffness-to-weight ratios. Future reusable space launch vehicles and space exploration structures will need advanced light weight composites in order to minimize vehicle weight while demonstrating robustness and durability, guaranteeing high factors of safety. In particular, the implementation of composite cryogenic propellant fuel tanks (cryotanks) for future reusable launch vehicles (RLVs) could greatly reduce the vehicle's weight versus identically sized cryotanks constructed of metallic materials. One candidate composite material for future cryotank designs is IM7/977-2, which is a graphite/epoxy system. A successful candidate must demonstrate reasonable structural properties over a wide range of temperatures. Since the matrix material is normally the weak link in the composite, tests that emphasize matrix-dominated behavior need to be conducted. Therefore, the objective of this work is to determine the mode I interlaminar fracture toughness of "unidirectional" 8-ply and 16-ply IM7/977-2 through experimental testing. Tests were performed at -196 degrees Celsius (-320 degrees Fahrenheit), 22 degrees Celsius (72 degrees Fahrenheit), 93 degrees Celsius (200 degrees Fahrenheit) and 160 degrees C (320 degrees Fahrenheit). Low temperature testing was completed while the specimen was submerged in a liquid nitrogen bath. High temperature testing was completed in a temperature-controlled oven.

Experimental study of a valveless pulse detonation rocket engine using nontoxic hypergolic propellants

NASA Astrophysics Data System (ADS)

Kan, Brandon K.

A pulsed detonation rocket engine concept was explored through the use of hypergolic propellants in a fuel-centered pintle injector combustor. The combustor design yielded a simple open ended chamber with a pintle type injection element and pressure instrumentation. High-frequency pressure measurements from the first test series showed the presence of large pressure oscillations in excess of 2000 psia at frequencies between 400-600 hz during operation. High-speed video confirmed the high-frequency pulsed behavior and large amounts of after burning. Damaged hardware and instrumentation failure limited the amount of data gathered in the first test series, but the experiments met original test objectives of producing large over-pressures in an open chamber. A second test series proceeded by replacing hardware and instrumentation, and new data showed that pulsed events produced under expanded exhaust prior to pulsing, peak pressures around 8000 psi, and operating frequencies between 400-800 hz. Later hot-fires produced no pulsed behavior despite undamaged hardware. The research succeeded in producing pulsed combustion behavior using hypergolic fuels in a pintle injector setup and provided insights into design concepts that would assist future injector designs and experimental test setups.

Development of the NTF-117S Semi-Span Balance

NASA Technical Reports Server (NTRS)

Lynn, Keith C.

2010-01-01

A new high-capacity semi-span force and moment balance has recently been developed for use at the National Transonic Facility at the NASA Langley Research Center. This new semi-span balance provides the NTF a new measurement capability that will support testing of semi-span test models at transonic high-lift testing regimes. Future testing utilizing this new balance capability will include active circulation control and propulsion simulation testing of semi-span transonic wing models. The NTF has recently implemented a new highpressure air delivery station that will provide both high and low mass flow pressure lines that are routed out to the semi-span models via a set high/low pressure bellows that are indirectly linked to the metric end of the NTF-117S balance. A new check-load stand is currently being developed to provide the NTF with an in-house capability that will allow for performing check-loads on the NTF-117S balance in order to determine the pressure tare affects on the overall performance of the balance. An experimental design is being developed that will allow for experimentally assessing the static pressure tare affects on the balance performance.

Progress In Plasma Accelerator Development for Dynamic Formation of Plasma Liners

NASA Technical Reports Server (NTRS)

Thio, Y. C. Francis; Eskridge, Richard; Martin, Adam; Smith, James; Lee, Michael; Cassibry, Jason T.; Griffin, Steven; Rodgers, Stephen L. (Technical Monitor)

2002-01-01

An experimental plasma accelerator for magnetic target fusion (MTF) applications under development at the NASA Marshall Space Flight Center is described. The accelerator is a coaxial pulsed plasma thruster (Figure 1). It has been tested experimentally and plasma jet velocities of approx.50 km/sec have been obtained. The plasma jet has been photographed with 10-ns exposure times to reveal a stable and repeatable plasma structure (Figure 2). Data for velocity profile information has been obtained using light pipes and magnetic probes embedded in the gun walls to record the plasma and current transit respectively at various barrel locations. Preliminary spatially resolved spectral data and magnetic field probe data are also presented. A high speed triggering system has been developed and tested as a means of reducing the gun "jitter". This jitter is being characterized and future work for second generation "ultra-low jitter" gun development is being identified.

Plasma Accelerator Development for Dynamic Formation of Plasma Liners: A Status Report

NASA Technical Reports Server (NTRS)

Thio, Y. C. Francis; Eskridge, Richard; Martin, Adam; Smith, James; Lee, Michael; Rodgers, Stephen L. (Technical Monitor)

2001-01-01

An experimental plasma accelerator for magnetic target fusion (MTF) applications under development at the NASA Marshall Space Flight Center is described. The accelerator is a pulsed plasma thruster and has been tested experimentally and plasma jet velocities of approximately 50 km/sec have been obtained. The plasma jet structure has been photographed with 10 ns exposure times to reveal a stable and repeatable plasma structure. Data for velocity profile information has been obtained using light pipes embedded in the gun walls to record the plasma transit at various barrel locations. Preliminary spatially resolved spectral data and magnetic field probe data are also presented. A high speed triggering system has been developed and tested as a means of reducing the gun "jitter". This jitter is being characterized and future work for second generation "ultra-low jitter" gun development is being identified.

Performance of the first Japanese large-scale facility for radon inhalation experiments with small animals.

PubMed

Ishimori, Yuu; Mitsunobu, Fumihiro; Yamaoka, Kiyonori; Tanaka, Hiroshi; Kataoka, Takahiro; Sakoda, Akihiro

2011-07-01

A radon test facility for small animals was developed in order to increase the statistical validity of differences of the biological response in various radon environments. This paper illustrates the performances of that facility, the first large-scale facility of its kind in Japan. The facility has a capability to conduct approximately 150 mouse-scale tests at the same time. The apparatus for exposing small animals to radon has six animal chamber groups with five independent cages each. Different radon concentrations in each animal chamber group are available. Because the first target of this study is to examine the in vivo behaviour of radon and its effects, the major functions to control radon and to eliminate thoron were examined experimentally. Additionally, radon progeny concentrations and their particle size distributions in the cages were also examined experimentally to be considered in future projects.

Learning to Dislike Chocolate: Conditioning Negative Attitudes toward Chocolate and Its Effect on Chocolate Consumption.

PubMed

Wang, Yan; Wang, Guosen; Zhang, Dingyuan; Wang, Lei; Cui, Xianghua; Zhu, Jinglei; Fang, Yuan

2017-01-01

Evaluative conditioning (EC) procedures can be used to form and change attitudes toward a wide variety of objects. The current study examined the effects of a negative EC procedure on attitudes toward chocolate, and whether it influenced chocolate evaluation and consumption. Participants were randomly assigned to the experimental condition in which chocolate images were paired with negative stimuli, or the control condition in which chocolate images were randomly paired with positive stimuli (50%) and negative stimuli (50%). Explicit and implicit attitudes toward chocolate images were collected. During an ostensible taste test, chocolate evaluation and consumption were assessed. Results revealed that compared to participants in the control condition, participants in the experimental condition showed more negative explicit and implicit attitudes toward chocolate images and evaluated chocolate more negatively during the taste test. However, chocolate consumption did not differ between experimental and control conditions. These findings suggest that pairing chocolate with negative stimuli can influence attitudes toward chocolate, though behavioral effects are absent. Intervention applications of EC provide avenues for future research and practices.

Learning to Dislike Chocolate: Conditioning Negative Attitudes toward Chocolate and Its Effect on Chocolate Consumption

PubMed Central

Wang, Yan; Wang, Guosen; Zhang, Dingyuan; Wang, Lei; Cui, Xianghua; Zhu, Jinglei; Fang, Yuan

2017-01-01

Evaluative conditioning (EC) procedures can be used to form and change attitudes toward a wide variety of objects. The current study examined the effects of a negative EC procedure on attitudes toward chocolate, and whether it influenced chocolate evaluation and consumption. Participants were randomly assigned to the experimental condition in which chocolate images were paired with negative stimuli, or the control condition in which chocolate images were randomly paired with positive stimuli (50%) and negative stimuli (50%). Explicit and implicit attitudes toward chocolate images were collected. During an ostensible taste test, chocolate evaluation and consumption were assessed. Results revealed that compared to participants in the control condition, participants in the experimental condition showed more negative explicit and implicit attitudes toward chocolate images and evaluated chocolate more negatively during the taste test. However, chocolate consumption did not differ between experimental and control conditions. These findings suggest that pairing chocolate with negative stimuli can influence attitudes toward chocolate, though behavioral effects are absent. Intervention applications of EC provide avenues for future research and practices. PMID:28900409

Reliability based design including future tests and multiagent approaches

NASA Astrophysics Data System (ADS)

Villanueva, Diane

The initial stages of reliability-based design optimization involve the formulation of objective functions and constraints, and building a model to estimate the reliability of the design with quantified uncertainties. However, even experienced hands often overlook important objective functions and constraints that affect the design. In addition, uncertainty reduction measures, such as tests and redesign, are often not considered in reliability calculations during the initial stages. This research considers two areas that concern the design of engineering systems: 1) the trade-off of the effect of a test and post-test redesign on reliability and cost and 2) the search for multiple candidate designs as insurance against unforeseen faults in some designs. In this research, a methodology was developed to estimate the effect of a single future test and post-test redesign on reliability and cost. The methodology uses assumed distributions of computational and experimental errors with re-design rules to simulate alternative future test and redesign outcomes to form a probabilistic estimate of the reliability and cost for a given design. Further, it was explored how modeling a future test and redesign provides a company an opportunity to balance development costs versus performance by simultaneously designing the design and the post-test redesign rules during the initial design stage. The second area of this research considers the use of dynamic local surrogates, or surrogate-based agents, to locate multiple candidate designs. Surrogate-based global optimization algorithms often require search in multiple candidate regions of design space, expending most of the computation needed to define multiple alternate designs. Thus, focusing on solely locating the best design may be wasteful. We extended adaptive sampling surrogate techniques to locate multiple optima by building local surrogates in sub-regions of the design space to identify optima. The efficiency of this method was studied, and the method was compared to other surrogate-based optimization methods that aim to locate the global optimum using two two-dimensional test functions, a six-dimensional test function, and a five-dimensional engineering example.

Regeneratively cooled rocket engine for space storable propellants

NASA Technical Reports Server (NTRS)

Wagner, W. R.

1973-01-01

Analysis, design, fabrication, and test efforts were performed for the existing OF2/B2H6 regeneratively cooled lK (4448 N) thrust chamber to illustrate simultaneous B2H6 fuel and OF2 oxidizer cooling and to provide results for a gaseous propellant condition injected into the combustion chamber. Data derived from performance, thermal and flow measurements confirmed predictions derived from previous test work and from concurrent analytical study. Development data derived from the experimental study were indicated to be sufficient to develop a preflight thrust chamber demonstrator prototype for future space mission objectives.

Validation of fault-free behavior of a reliable multiprocessor system - FTMP: A case study. [Fault-Tolerant Multi-Processor avionics

NASA Technical Reports Server (NTRS)

Clune, E.; Segall, Z.; Siewiorek, D.

1984-01-01

A program of experiments has been conducted at NASA-Langley to test the fault-free performance of a Fault-Tolerant Multiprocessor (FTMP) avionics system for next-generation aircraft. Baseline measurements of an operating FTMP system were obtained with respect to the following parameters: instruction execution time, frame size, and the variation of clock ticks. The mechanisms of frame stretching were also investigated. The experimental results are summarized in a table. Areas of interest for future tests are identified, with emphasis given to the implementation of a synthetic workload generation mechanism on FTMP.

A Unique Software System For Simulation-to-Flight Research

NASA Technical Reports Server (NTRS)

Chung, Victoria I.; Hutchinson, Brian K.

2001-01-01

"Simulation-to-Flight" is a research development concept to reduce costs and increase testing efficiency of future major aeronautical research efforts at NASA. The simulation-to-flight concept is achieved by using common software and hardware, procedures, and processes for both piloted-simulation and flight testing. This concept was applied to the design and development of two full-size transport simulators, a research system installed on a NASA B-757 airplane, and two supporting laboratories. This paper describes the software system that supports the simulation-to-flight facilities. Examples of various simulation-to-flight experimental applications were also provided.

They See a Rat, We Seek a Cure for Diseases: The Current Status of Animal Experimentation in Medical Practice

PubMed Central

Kehinde, Elijah O.

2013-01-01

The objective of this review article was to examine current and prospective developments in the scientific use of laboratory animals, and to find out whether or not there are still valid scientific benefits of and justification for animal experimentation. The PubMed and Web of Science databases were searched using the following key words: animal models, basic research, pharmaceutical research, toxicity testing, experimental surgery, surgical simulation, ethics, animal welfare, benign, malignant diseases. Important relevant reviews, original articles and references from 1970 to 2012 were reviewed for data on the use of experimental animals in the study of diseases. The use of laboratory animals in scientific research continues to generate intense public debate. Their use can be justified today in the following areas of research: basic scientific research, use of animals as models for human diseases, pharmaceutical research and development, toxicity testing and teaching of new surgical techniques. This is because there are inherent limitations in the use of alternatives such as in vitro studies, human clinical trials or computer simulation. However, there are problems of transferability of results obtained from animal research to humans. Efforts are on-going to find suitable alternatives to animal experimentation like cell and tissue culture and computer simulation. For the foreseeable future, it would appear that to enable scientists to have a more precise understanding of human disease, including its diagnosis, prognosis and therapeutic intervention, there will still be enough grounds to advocate animal experimentation. However, efforts must continue to minimize or eliminate the need for animal testing in scientific research as soon as possible. PMID:24217224

They see a rat, we seek a cure for diseases: the current status of animal experimentation in medical practice.

PubMed

Kehinde, Elijah O

2013-01-01

The objective of this review article was to examine current and prospective developments in the scientific use of laboratory animals, and to find out whether or not there are still valid scientific benefits of and justification for animal experimentation. The PubMed and Web of Science databases were searched using the following key words: animal models, basic research, pharmaceutical research, toxicity testing, experimental surgery, surgical simulation, ethics, animal welfare, benign, malignant diseases. Important relevant reviews, original articles and references from 1970 to 2012 were reviewed for data on the use of experimental animals in the study of diseases. The use of laboratory animals in scientific research continues to generate intense public debate. Their use can be justified today in the following areas of research: basic scientific research, use of animals as models for human diseases, pharmaceutical research and development, toxicity testing and teaching of new surgical techniques. This is because there are inherent limitations in the use of alternatives such as in vitro studies, human clinical trials or computer simulation. However, there are problems of transferability of results obtained from animal research to humans. Efforts are on-going to find suitable alternatives to animal experimentation like cell and tissue culture and computer simulation. For the foreseeable future, it would appear that to enable scientists to have a more precise understanding of human disease, including its diagnosis, prognosis and therapeutic intervention, there will still be enough grounds to advocate animal experimentation. However, efforts must continue to minimize or eliminate the need for animal testing in scientific research as soon as possible. © 2013 S. Karger AG, Basel.

Waterhammer Transient Simulation and Model Anchoring for the Robotic Lunar Lander Propulsion System

NASA Technical Reports Server (NTRS)

Stein, William B.; Trinh, Huu P.; Reynolds, Michael E.; Sharp, David J.

2011-01-01

Waterhammer transients have the potential to adversely impact propulsion system design if not properly addressed. Waterhammer can potentially lead to system plumbing, and component damage. Multi-thruster propulsion systems also develop constructive/destructive wave interference which becomes difficult to predict without detailed models. Therefore, it is important to sufficiently characterize propulsion system waterhammer in order to develop a robust design with minimal impact to other systems. A risk reduction activity was performed at Marshall Space Flight Center to develop a tool for estimating waterhammer through the use of anchored simulation for the Robotic Lunar Lander (RLL) propulsion system design. Testing was performed to simulate waterhammer surges due to rapid valve closure and consisted of twenty-two series of waterhammer tests, resulting in more than 300 valve actuations. These tests were performed using different valve actuation schemes and three system pressures. Data from the valve characterization tests were used to anchor the models that employed MSCSoftware.EASY5 v.2010 to model transient fluid phenomena by using transient forms of mass and energy conservation. The anchoring process was performed by comparing initial model results to experimental data and then iterating the model input to match the simulation results with the experimental data. The models provide good correlation with experimental results, supporting the use of EASY5 as a tool to model fluid transients and provide a baseline for future RLL system modeling. This paper addresses tasks performed during the waterhammer risk reduction activity for the RLL propulsion system. The problem of waterhammer simulation anchoring as applied to the RLL system is discussed with results from the corresponding experimental valve tests. Important factors for waterhammer mitigation are discussed along with potential design impacts to the RLL propulsion system.

Delay of Gratification, Delay Discounting and their Associations with Age, Episodic Future Thinking, and Future Time Perspective.

PubMed

Göllner, Lars M; Ballhausen, Nicola; Kliegel, Matthias; Forstmeier, Simon

2017-01-01

The delay of gratification (DoG) in children is widely investigated with an experimental procedure originally called the "marshmallow test," whereas the studies on self-regulation (SR) in adolescents and adults usually use self-report questionnaires. Delay discounting (DD) measures simplify the DoG procedure and focus on monetary rewards. The aim of this study was to investigate age differences in DoG and DD from childhood to old age using a test that is suitable for both children and adults. Furthermore, investigations were conducted on the association between DoG/DD and two future orientation constructs [future time perspective (FTP) and episodic future thinking (EFT)] as well as age differences in these constructs. Participants from five age groups (9-14, 18-25, 35-55, 65-80, 80+) participated in the study ( N = 96). While we found no age difference for DoG, DD was the lowest [i.e., self-control (SC) was the highest] in young/middle adults; however, it was the highest (i.e., SC was the lowest) in children and old/oldest adults. Furthermore, we found significant age differences for DD and FTP. As predicted, there were strong correlations between DoG and FTP and between DD and FTP, but not between DoG/DD and EFT. These results indicate that age differences in SR vary across the measures used. Individuals who generally think and act in a future-oriented manner have a stronger ability to delay gratification.

Indentation-Enabled In Situ Mechanical Characterization of Micro/Nanopillars in Electron Microscopes

NASA Astrophysics Data System (ADS)

Guo, Qiang; Fu, Xidan; Guo, Xiaolei; Liu, Zhiying; Shi, Yan; Zhang, Di

2018-04-01

Indentation-enabled micro/nanomechanical characterization of small-scale specimens provides powerful new tools for probing materials properties that were once unattainable by conventional experimental methods. Recent advancement in instrumentation further allows mechanical testing to be carried out in situ in electron microscopes, with high spatial and temporal resolution. This review discusses the recent development of nanoindentation-enabled in situ mechanical testing in electron microscopes, with an emphasis on the study of micro/nanopillars. Focus is given to novel applications beyond simple compressive and tensile testing that have been developed in the past few years, and limitations and possible future research directions in this field are proposed and discussed.

Facilitating the learning process: a pilot study of collaborative testing vs individualistic testing in the chiropractic college setting.

PubMed

Meseke, Jamie K; Nafziger, Rita; Meseke, Christopher A

2008-05-01

This pilot study examines the effect collaborative testing has on achievement of students taking a basic science course at a chiropractic college. The grades of 2 cohorts of students taking a basic science course were compared: the control group from the first academic term (n = 73) and the experimental group from the second academic term (n = 41). The control cohort completed weekly quizzes as individuals. The experimental cohort completed the weekly quizzes in small collaborative groups. All unit examinations and the final examination were taken by both cohorts individually. Grades for each cohort were derived from 6 weekly unit quizzes, 3 unit examinations, and a comprehensive final examination. Overall, the experimental group differed from the control group (Wilks' Lambda = 0.318; F(10,103) = 22.052; and P < .001). All quiz scores were significantly higher for the experimental group as compared with the control group. In addition, overall point totals and final course grades also differed significantly. No significant differences, however, were observed in either the first 2 unit examination scores or the final examination scores. These results confirm previous reports that student performance is enhanced by collaborative learning. Collaborative testing provided students with the opportunity to discuss their reasoning and receive immediate feedback from other group members regarding their rationale, which potentially enhanced understanding of course material. Students were encouraged to become more active in the course as group discussions emerged from individual perspectives. The collaborative learning process may enhance critical thinking abilities, which are vital for future chiropractic practitioners.

Experimental gravitation in space - Is there a future?

NASA Astrophysics Data System (ADS)

Wharton, R. A.; McKay, C. P.; Mancinelli, R. L.; Simmons, G. M.

Experimental gravitation enters the 1990s with a past full of successes, but with a future full of uncertainties. Intellectually, the field is as vigorous as ever, with major thrusts in three main areas: the search for gravitational radiation, the study of post and post-post Newtonian effects, and the detection of hypothetical feeble new interactions. It is the only branch of space research involved in fundamental physics. But politically and financially, the future is uncertain. Competition for funding and for flight opportunities will be stiff for the foreseeable future, both with other disciplines such as astrophysics, planetary science and the military, and within experimental gravitation itself. Difficult choices lie ahead. This paper reviews the current state of the field and attempts to peer into the future.

Review of Transient Testing of Fast Reactor Fuels in the Transient REActor Test Facility (TREAT)

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

Jensen, C.; Wachs, D.; Carmack, J.

The restart of the Transient REActor Test (TREAT) facility provides a unique opportunity to engage the fast reactor fuels community to reinitiate in-pile experimental safety studies. Historically, the TREAT facility played a critical role in characterizing the behavior of both metal and oxide fast reactor fuels under off-normal conditions, irradiating hundreds of fuel pins to support fast reactor fuel development programs. The resulting test data has provided validation for a multitude of fuel performance and severe accident analysis computer codes. This paper will provide a review of the historical database of TREAT experiments including experiment design, instrumentation, test objectives, andmore » salient findings. Additionally, the paper will provide an introduction to the current and future experiment plans of the U.S. transient testing program at TREAT.« less

Study on the Effects of Individualized Learning Therapy on Cognitive Function and Behavioral and Psychological Symptoms of Dementia in the Institutionalized Older Adults.

PubMed

Chen, Hsiao-Mei; Tsai, Li-Jane; Chao, Shu-Yuan; Clark, Mary Jo

2016-12-01

The increasing number of elderly people affected by dementia in Taiwan has made dementia care a crucial issue of concern. This issue is particularly important in terms of the proper management of behavioral symptoms and improvement of the cognitive functions of those affected by this disease. This study examined the effects of individualized learning therapy on cognition and neuropsychiatric symptoms among elderly people with dementia. A quasi-experimental, pretest-posttest research design was adopted. We recruited elderly people with dementia at the only two institutions for elderly patients with dementia in Central Taiwan. These institutions were assigned randomly as the experimental or control group, with totals of 23 and 21 participants, respectively. The participants in the experimental group received individualized learning therapy for 30 minutes twice weekly for 3 months. The comparison group received usual care only. The cognitive function and neuropsychiatric symptoms of all participants were measured using the Mini-Mental Status Examination (MMSE) before the start of and immediately after the 12-week intervention and the Chinese version of the Neuropsychiatric Inventory (CNPI), which was administered once per week during the intervention. Independent t tests (or Mann-Whitney U tests), chi-square tests (or Fisher's exact tests), paired t test, and generalized estimating equations were used for data analysis. Participants in the experimental group had significantly higher MMSE scores (p < .01) and lower CNPI scores (p < .01) than their comparison group peers after the intervention. Furthermore, the neuropsychiatric symptoms in the experimental group such as hallucinations, bizarre behavior, depression, apathetic expression, irritability, and sleep disorder had significantly improved by the seventh week. Individualized learning therapy may be an effective approach to improve cognitive function and reduce neuropsychiatric symptoms among older people with dementia. Therefore, future clinical application is warranted.

Investigation of Insulation Materials for Future Radioisotope Power Systems (RPS)

NASA Technical Reports Server (NTRS)

Cornell, Peggy A.; Hurwitz, Frances I.; Ellis, David L.; Schmitz, Paul C.

2013-01-01

NASA's Radioisotope Power System (RPS) Technology Advancement Project is developing next generation high temperature insulation materials that directly benefit thermal management and improve performance of RPS for future science missions. Preliminary studies on the use of multilayer insulation (MLI) for Stirling convertors used on the Advanced Stirling Radioisotope Generator (ASRG) have shown the potential benefits of MLI for space vacuum applications in reducing generator size and increasing specific power (W/kg) as compared to the baseline Microtherm HT (Microtherm, Inc.) insulation. Further studies are currently being conducted at NASA Glenn Research Center (GRC) on candidate MLI foils and aerogel composite spacers. This paper presents the method of testing of foils and spacers and experimental results to date.

Investigation of Insulation Materials for Future Radioisotope Power Systems

NASA Technical Reports Server (NTRS)

Cornell, Peggy A.; Hurwitz, Frances I.; Ellis, David L.; Schmitz, Paul C.

2013-01-01

NASA's Radioisotope Power Systems (RPS) Technology Advancement Project is developing next generation high-temperature insulation materials that directly benefit thermal management and improve performance of RPS for future science missions. Preliminary studies on the use of multilayer insulation (MLI) for Stirling convertors used on the Advanced Stirling Radioisotope Generator (ASRG) have shown the potential benefits of MLI for space vacuum applications in reducing generator size and increasing specific power (W/kg) as compared to the baseline Microtherm HT (Microtherm, Inc.) insulation. Further studies are currently being conducted at NASA Glenn Research Center on candidate MLI foils and aerogel composite spacers. This paper presents the method of testing of foils and spacers and experimental results to date.

Changing health behaviors to improve health outcomes after angioplasty: a randomized trial of net present value versus future value risk communication.

PubMed

Charlson, M E; Peterson, J C; Boutin-Foster, C; Briggs, W M; Ogedegbe, G G; McCulloch, C E; Hollenberg, J; Wong, C; Allegrante, J P

2008-10-01

Patients who have undergone angioplasty experience difficulty modifying at-risk behaviors for subsequent cardiac events. The purpose of this study was to test whether an innovative approach to framing of risk, based on 'net present value' economic theory, would be more effective in behavioral intervention than the standard 'future value approach' in reducing cardiovascular morbidity and mortality following angioplasty. At baseline, all patients completed a health assessment, received an individualized risk profile and selected risk factors for modification. The intervention randomized patients into two varying methods for illustrating positive effects of behavior change. For the experimental group, each selected risk factor was assigned a numeric biologic age (the net present value) that approximated the relative potential to improve current health status and quality of life when modifying that risk factor. In the control group, risk reduction was framed as the value of preventing future health problems. Ninety-four percent of patients completed 2-year follow-up. There was no difference between the rates of death, stroke, myocardial infarction, Class II-IV angina or severe ischemia (on non-invasive testing) between the net present value group and the future value group. Our results show that a net present risk communication intervention did not result in significant differences in health outcomes.

Biomedical Analyses, Tolerance, and Mitigation of Acute and Chronic Trauma

DTIC Science & Technology

2012-07-01

aligned such that in one group the heads were constrained to rotate in the mid-sagittal line and in the other group head was angulated about all three...the restrained than in the unrestrained groups indicating the role of posture on trauma. Uniaxial force gages introduced into the C5-C6...directions for future experimental design. Tests conducted on the Hybrid-III ATD with both curved and straightened lumbar spines demonstrated that

SPHERES test

NASA Image and Video Library

2013-07-05

ISS036-E-015549 (5 July 2013) --- In the International Space Station’s Kibo laboratory, NASA astronaut Chris Cassidy, Expedition 36 flight engineer, watches as he devotes some time with the long-running SPHERES experiment, also known as Synchronized Position Hold Engage and Reorient Experimental Satellites. The experiment is run in conjunction with students who program bowling ball-sized satellites using algorithms. The free-floating satellites are programmed to perform maneuvers potentially influencing the design of future missions.

Implementation of input command shaping to reduce vibration in flexible space structures

NASA Technical Reports Server (NTRS)

Chang, Kenneth W.; Seering, Warren P.; Rappole, B. Whitney

1992-01-01

Viewgraphs on implementation of input command shaping to reduce vibration in flexible space structures are presented. Goals of the research are to explore theory of input command shaping to find an efficient algorithm for flexible space structures; to characterize Middeck Active Control Experiment (MACE) test article; and to implement input shaper on the MACE structure and interpret results. Background on input shaping, simulation results, experimental results, and future work are included.

Experimental and Numerical Analysis of Triaxially Braided Composites Utilizing a Modified Subcell Modeling Approach

NASA Technical Reports Server (NTRS)

Cater, Christopher; Xiao, Xinran; Goldberg, Robert K.; Kohlman, Lee W.

2015-01-01

A combined experimental and analytical approach was performed for characterizing and modeling triaxially braided composites with a modified subcell modeling strategy. Tensile coupon tests were conducted on a [0deg/60deg/-60deg] braided composite at angles of 0deg, 30deg, 45deg, 60deg and 90deg relative to the axial tow of the braid. It was found that measured coupon strength varied significantly with the angle of the applied load and each coupon direction exhibited unique final failures. The subcell modeling approach implemented into the finite element software LS-DYNA was used to simulate the various tensile coupon test angles. The modeling approach was successful in predicting both the coupon strength and reported failure mode for the 0deg, 30deg and 60deg loading directions. The model over-predicted the strength in the 90deg direction; however, the experimental results show a strong influence of free edge effects on damage initiation and failure. In the absence of these local free edge effects, the subcell modeling approach showed promise as a viable and computationally efficient analysis tool for triaxially braided composite structures. Future work will focus on validation of the approach for predicting the impact response of the braided composite against flat panel impact tests.

Experimental and Numerical Analysis of Triaxially Braided Composites Utilizing a Modified Subcell Modeling Approach

NASA Technical Reports Server (NTRS)

Cater, Christopher; Xiao, Xinran; Goldberg, Robert K.; Kohlman, Lee W.

2015-01-01

A combined experimental and analytical approach was performed for characterizing and modeling triaxially braided composites with a modified subcell modeling strategy. Tensile coupon tests were conducted on a [0deg/60deg/-60deg] braided composite at angles [0deg, 30deg, 45deg, 60deg and 90deg] relative to the axial tow of the braid. It was found that measured coupon strength varied significantly with the angle of the applied load and each coupon direction exhibited unique final failures. The subcell modeling approach implemented into the finite element software LS-DYNA was used to simulate the various tensile coupon test angles. The modeling approach was successful in predicting both the coupon strength and reported failure mode for the 0deg, 30deg and 60deg loading directions. The model over-predicted the strength in the 90deg direction; however, the experimental results show a strong influence of free edge effects on damage initiation and failure. In the absence of these local free edge effects, the subcell modeling approach showed promise as a viable and computationally efficient analysis tool for triaxially braided composite structures. Future work will focus on validation of the approach for predicting the impact response of the braided composite against flat panel impact tests.

Multiple Restart Testing of a Stainless Steel Sodium Heat Pipe Module

NASA Technical Reports Server (NTRS)

Martin, James; Mireles, Omar; Reid, Robert

2005-01-01

A heat pipe cooled reactor is one of several candidate reactor cores being considered for space power and propulsion systems to support future space exploration activities. Long life heat pipe modules. with designs verified through a combination of theoretical analysis and experimental evaluations. would be necessary to establish the viability of this option. A hardware-based program was initiated to begin experimental testing of components to verify compliance of proposed designs. To this end, a number of stainless steel/sodium heat pipe modules have been designed and fabricated to support experimental testing of a Safe Affordable Fission Engine (SAFE) project, a 100-kWt core design pursued jointly by the Marshall Space Flight Center and the Los Alamos National Laboratory. One of the SAFE heat pipe modules was successfully subjected to over 200 restarts. examining the behavior of multiple passive freeze/thaw operations. Typical operation included a 1-hour startup to an average evaporator temperature of 1000 K followed by a 15 minute hold at temperature. Nominal maximum input power during the hold period was 1.9 kW. Between heating cycles the module was cooled to less than 325 K, returning the sodium to a frozen state in preparation fop the next startup cycle.

Results from a scaled reactor cavity cooling system with water at steady state

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

Lisowski, D. D.; Albiston, S. M.; Tokuhiro, A.

We present a summary of steady-state experiments performed with a scaled, water-cooled Reactor Cavity Cooling System (RCCS) at the Univ. of Wisconsin - Madison. The RCCS concept is used for passive decay heat removal in the Next Generation Nuclear Plant (NGNP) design and was based on open literature of the GA-MHTGR, HTR-10 and AVR reactor. The RCCS is a 1/4 scale model of the full scale prototype system, with a 7.6 m structure housing, a 5 m tall test section, and 1,200 liter water storage tank. Radiant heaters impose a heat flux onto a three riser tube test section, representingmore » a 5 deg. radial sector of the actual 360 deg. RCCS design. The maximum heat flux and power levels are 25 kW/m{sup 2} and 42.5 kW, and can be configured for variable, axial, or radial power profiles to simulate prototypic conditions. Experimental results yielded measurements of local surface temperatures, internal water temperatures, volumetric flow rates, and pressure drop along the test section and into the water storage tank. The majority of the tests achieved a steady state condition while remaining single-phase. A selected number of experiments were allowed to reach saturation and subsequently two-phase flow. RELAP5 simulations with the experimental data have been refined during test facility development and separate effects validation of the experimental facility. This test series represents the completion of our steady-state testing, with future experiments investigating normal and off-normal accident scenarios with two-phase flow effects. The ultimate goal of the project is to combine experimental data from UW - Madison, UI, ANL, and Texas A and M, with system model simulations to ascertain the feasibility of the RCCS as a successful long-term heat removal system during accident scenarios for the NGNP. (authors)« less

TREAT Neutronics Analysis and Design Support, Part II: Multi-SERTTA-CAL

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

Bess, John D.; Woolstenhulme, Nicolas E.; Hill, Connie M.

2016-08-01

Experiment vehicle design is necessary in preparation for Transient Reactor Test (TREAT) facility restart and the resumption of transient testing to support Accident Tolerant Fuel (ATF) characterization and other future fuels testing requirements. Currently the most mature vehicle design is the Multi-SERTTA (Static Environments Rodlet Transient Test Apparatuses), which can accommodate up to four concurrent rodlet-sized specimens under separate environmental conditions. Robust test vehicle design requires neutronics analyses to support design development, optimization of the power coupling factor (PCF) to efficiently maximize energy generation in the test fuel rodlets, and experiment safety analyses. In integral aspect of prior TREAT transientmore » testing was the incorporation of calibration experiments to experimentally evaluate and validate test conditions in preparation of the actual fuel testing. The calibration experiment package established the test parameter conditions to support fine-tuning of the computational models to deliver the required energy deposition to the fuel samples. The calibration vehicle was designed to be as near neutronically equivalent to the experiment vehicle as possible to minimize errors between the calibration and final tests. The Multi-SERTTA-CAL vehicle was designed to serve as the calibration vehicle supporting Multi-SERTTA experimentation. Models of the Multi-SERTTA-CAL vehicle containing typical PWR-fuel rodlets were prepared and neutronics calculations were performed using MCNP6.1 with ENDF/B-VII.1 nuclear data libraries; these results were then compared against those performed for Multi-SERTTA to determine the similarity and possible design modification necessary prior to construction of these experiment vehicles. The estimated reactivity insertion worth into the TREAT core is very similar between the two vehicle designs, with the primary physical difference being a hollow Inconel tube running down the length of the calibration vehicle. Calculations of PCF indicate that on average there is a reduction of approximately 6.3 and 12.6%, respectively, for PWR fuel rodlets irradiated under wet and dry conditions. Changes to the primary or secondary vessel structure in the calibration vehicle can be performed to offset this discrepancy and maintain neutronic equivalency. Current possible modifications to the calibration vehicle include reduction of the primary vessel wall thickness, swapping Zircaloy-4 for stainless steel 316 in the secondary containment, or slight modification to the temperature and pressure of the water environment within the primary vessel. Removal of some of the instrumentation within the calibration vehicle can also serve to slightly increase the PCF. Future efforts include further modification and optimization of the Multi-SERTTA and Multi-SERTTA-CAL designs in preparation of actual TREAT transient testing. Experimental results from both test vehicles will be compared against calculational results and methods to provide validation and support additional neutronics analyses.« less

Analysis, testing, and evaluation of faulted and unfaulted Wye, Delta, and open Delta connected electromechanical actuators

NASA Technical Reports Server (NTRS)

Nehl, T. W.; Demerdash, N. A.

1983-01-01

Mathematical models capable of simulating the transient, steady state, and faulted performance characteristics of various brushless dc machine-PSA (power switching assembly) configurations were developed. These systems are intended for possible future use as primemovers in EMAs (electromechanical actuators) for flight control applications. These machine-PSA configurations include wye, delta, and open-delta connected systems. The research performed under this contract was initially broken down into the following six tasks: development of mathematical models for various machine-PSA configurations; experimental validation of the model for failure modes; experimental validation of the mathematical model for shorted turn-failure modes; tradeoff study; and documentation of results and methodology.

The structure of the nucleon: Elastic electromagnetic form factors

DOE PAGES

Punjabi, V.; Perdrisat, C. F.; Jones, M. K.; ...

2015-07-10

Precise proton and neutron form factor measurements at Jefferson Lab, using spin observables, have recently made a significant contribution to the unraveling of the internal structure of the nucleon. Accurate experimental measurements of the nucleon form factors are a test-bed for understanding how the nucleon's static properties and dynamical behavior emerge from QCD, the theory of the strong interactions between quarks. There has been enormous theoretical progress, since the publication of the Jefferson Lab proton form factor ratio data, aiming at reevaluating the picture of the nucleon. We will review the experimental and theoretical developments in this field and discussmore » the outlook for the future.« less

Design standards for experimental and field studies to evaluate diagnostic accuracy of tests for infectious diseases in aquatic animals.

PubMed

Laurin, E; Thakur, K K; Gardner, I A; Hick, P; Moody, N J G; Crane, M S J; Ernst, I

2018-05-01

Design and reporting quality of diagnostic accuracy studies (DAS) are important metrics for assessing utility of tests used in animal and human health. Following standards for designing DAS will assist in appropriate test selection for specific testing purposes and minimize the risk of reporting biased sensitivity and specificity estimates. To examine the benefits of recommending standards, design information from published DAS literature was assessed for 10 finfish, seven mollusc, nine crustacean and two amphibian diseases listed in the 2017 OIE Manual of Diagnostic Tests for Aquatic Animals. Of the 56 DAS identified, 41 were based on field testing, eight on experimental challenge studies and seven on both. Also, we adapted human and terrestrial-animal standards and guidelines for DAS structure for use in aquatic animal diagnostic research. Through this process, we identified and addressed important metrics for consideration at the design phase: study purpose, targeted disease state, selection of appropriate samples and specimens, laboratory analytical methods, statistical methods and data interpretation. These recommended design standards for DAS are presented as a checklist including risk-of-failure points and actions to mitigate bias at each critical step. Adherence to standards when designing DAS will also facilitate future systematic review and meta-analyses of DAS research literature. © 2018 John Wiley & Sons Ltd.

A new UK fission yield evaluation UKFY3.7

NASA Astrophysics Data System (ADS)

Mills, Robert William

2017-09-01

The JEFF neutron induced and spontaneous fission product yield evaluation is currently unchanged from JEFF-3.1.1, also known by its UK designation UKFY3.6A. It is based upon experimental data combined with empirically fitted mass, charge and isomeric state models which are then adjusted within the experimental and model uncertainties to conform to the physical constraints of the fission process. A new evaluation has been prepared for JEFF, called UKFY3.7, that incorporates new experimental data and replaces the current empirical models (multi-Gaussian fits of mass distribution and Wahl Zp model for charge distribution combined with parameter extrapolation), with predictions from GEF. The GEF model has the advantage that one set of parameters allows the prediction of many different fissioning nuclides at different excitation energies unlike previous models where each fissioning nuclide at a specific excitation energy had to be fitted individually to the relevant experimental data. The new UKFY3.7 evaluation, submitted for testing as part of JEFF-3.3, is described alongside initial results of testing. In addition, initial ideas for future developments allowing inclusion of new measurements types and changing from any neutron spectrum type to true neutron energy dependence are discussed. Also, a method is proposed to propagate uncertainties of fission product yields based upon the experimental data that underlies the fission yield evaluation. The covariance terms being determined from the evaluated cumulative and independent yields combined with the experimental uncertainties on the cumulative yield measurements.

The effectiveness of parent participation in occupational therapy for children with developmental delay

PubMed Central

Lin, Chien-Lin; Lin, Chin-Kai; Yu, Jia-Jhen

2018-01-01

Introduction This study aims to explore the impact of Parent Participation Program on the development of developmental delay children. Methods Pretest-posttest equivalent-group experimental design study was used in this paper. A total of 30 pairs of developmental delay children aged 0–72 months and their parents participated into this study. They were divided into two groups, namely control group and experimental group, according to parents’ wishes. The objects of study in control group received 16 courses of direct rehabilitation therapy; those in experimental group received 8 courses of direct rehabilitation therapy and 8 courses of instruction and tracking of Parent Participation Program. The duration of the intervention was 8 weeks. All cases should be evaluated before and after the intervention, to analyze the difference before and after intervention and among groups. The statistical methods in this paper included descriptive analysis, Chi-square test, independent sample t-test, pair-sample t-test. Results and conclusion The intervention of Parent Participation Occupational Program has positive impact on the development of developmental delay children in various fields. Among all the intervention results, the progress of the experimental group is 1.895 times more than that of the control group. With parent involvement, Parent Participation Occupational Therapy can promote the cognitive ability, language ability, action ability (gross and fine movement), social competence and self-care ability of children with developmental delay. Finally, the researcher presents suggestions and directions for future research in accordance with the results. PMID:29503546

A randomized controlled trial of an intervention program to Brazilian mothers who use corporal punishment.

PubMed

Santini, Paolla Magioni; Williams, Lucia C A

2017-09-01

This study evaluated a positive parenting program to Brazilian mothers who used corporal punishment with their children. The intervention was conducted in four agencies serving vulnerable children, and at a home replica laboratory at the University. Mothers who admitted using corporal punishment were randomly assigned between experimental (n=20) and control group (n=20). The program consisted of 12 individual sessions using one unit from Projeto Parceria (Partnership Project), with specific guidelines and materials on positive parenting, followed by observational sessions of mother-child interaction with live coaching and a video feedback session in the lab. The study used an equivalent group experimental design with pre/post-test and follow-up, in randomized controlled trials. Measures involved: Initial Interview; Strengths and Difficulties Questionnaire (SDQ) - parent and child versions; Beck Depression Inventory (BDI); observational sessions with a protocol; and a Program Evaluation by participants. Analysis of mixed models for repeated measures revealed significant positive effects on the BDI and SDQ total scores, as well as less Conduct problems and Hyperactivity in SDQ measures from the experimental group mothers, comparing pre with post-test. Observational data also indicated significant improvement in positive interaction from the experimental group mothers at post-test, in comparison with controls. No significant results were found, however, in children's observational measures. Limitations of the study involved using a restricted sample, among others. Implications for future research are suggested. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Need for Precise and Well-documented Experimental Data on Prompt Fission Neutron Spectra from Neutron-induced Fission of {sup 239}Pu

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

Neudecker, D., E-mail: dneudecker@lanl.gov; Taddeucci, T.N.; Haight, R.C.

2016-01-15

The spectrum of neutrons emitted promptly after {sup 239}Pu(n,f)—a so-called prompt fission neutron spectrum (PFNS)—is a quantity of high interest, for instance, for reactor physics and global security. However, there are only few experimental data sets available that are suitable for evaluations. In addition, some of those data sets differ by more than their 1-σ uncertainty boundaries. We present the results of MCNP studies indicating that these differences are partly caused by underestimated multiple scattering contributions, over-corrected background, and inconsistent deconvolution methods. A detailed uncertainty quantification for suitable experimental data was undertaken including these effects, and test-evaluations were performed withmore » the improved uncertainty information. The test-evaluations illustrate that the inadequately estimated effects and detailed uncertainty quantification have an impact on the evaluated PFNS and associated uncertainties as well as the neutron multiplicity of selected critical assemblies. A summary of data and documentation needs to improve the quality of the experimental database is provided based on the results of simulations and test-evaluations. Given the possibly substantial distortion of the PFNS by multiple scattering and background effects, special care should be taken to reduce these effects in future measurements, e.g., by measuring the {sup 239}Pu PFNS as a ratio to either the {sup 235}U or {sup 252}Cf PFNS.« less

Distributed computing testbed for a remote experimental environment

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

Butner, D.N.; Casper, T.A.; Howard, B.C.

1995-09-18

Collaboration is increasing as physics research becomes concentrated on a few large, expensive facilities, particularly in magnetic fusion energy research, with national and international participation. These facilities are designed for steady state operation and interactive, real-time experimentation. We are developing tools to provide for the establishment of geographically distant centers for interactive operations; such centers would allow scientists to participate in experiments from their home institutions. A testbed is being developed for a Remote Experimental Environment (REE), a ``Collaboratory.`` The testbed will be used to evaluate the ability of a remotely located group of scientists to conduct research on themore » DIII-D Tokamak at General Atomics. The REE will serve as a testing environment for advanced control and collaboration concepts applicable to future experiments. Process-to-process communications over high speed wide area networks provide real-time synchronization and exchange of data among multiple computer networks, while the ability to conduct research is enhanced by adding audio/video communication capabilities. The Open Software Foundation`s Distributed Computing Environment is being used to test concepts in distributed control, security, naming, remote procedure calls and distributed file access using the Distributed File Services. We are exploring the technology and sociology of remotely participating in the operation of a large scale experimental facility.« less

Methodology of Blade Unsteady Pressure Measurement in the NASA Transonic Flutter Cascade

NASA Technical Reports Server (NTRS)

Lepicovsky, J.; McFarland, E. R.; Capece, V. R.; Jett, T. A.; Senyitko, R. G.

2002-01-01

In this report the methodology adopted to measure unsteady pressures on blade surfaces in the NASA Transonic Flutter Cascade under conditions of simulated blade flutter is described. The previous work done in this cascade reported that the oscillating cascade produced waves, which for some interblade phase angles reflected off the wind tunnel walls back into the cascade, interfered with the cascade unsteady aerodynamics, and contaminated the acquired data. To alleviate the problems with data contamination due to the back wall interference, a method of influence coefficients was selected for the future unsteady work in this cascade. In this approach only one blade in the cascade is oscillated at a time. The majority of the report is concerned with the experimental technique used and the experimental data generated in the facility. The report presents a list of all test conditions for the small amplitude of blade oscillations, and shows examples of some of the results achieved. The report does not discuss data analysis procedures like ensemble averaging, frequency analysis, and unsteady blade loading diagrams reconstructed using the influence coefficient method. Finally, the report presents the lessons learned from this phase of the experimental effort, and suggests the improvements and directions of the experimental work for tests to be carried out for large oscillation amplitudes.

A drilling tool design and in situ identification of planetary regolith mechanical parameters

NASA Astrophysics Data System (ADS)

Zhang, Weiwei; Jiang, Shengyuan; Ji, Jie; Tang, Dewei

2018-05-01

The physical and mechanical properties as well as the heat flux of regolith are critical evidence in the study of planetary origin and evolution. Moreover, the mechanical properties of planetary regolith have great value for guiding future human planetary activities. For planetary subsurface exploration, an inchworm boring robot (IBR) has been proposed to penetrate the regolith, and the mechanical properties of the regolith are expected to be simultaneously investigated during the penetration process using the drilling tool on the IBR. This paper provides a preliminary study of an in situ method for measuring planetary regolith mechanical parameters using a drilling tool on a test bed. A conical-screw drilling tool was designed, and its drilling load characteristics were experimentally analyzed. Based on the drilling tool-regolith interaction model, two identification methods for determining the planetary regolith bearing and shearing parameters are proposed. The bearing and shearing parameters of lunar regolith simulant were successfully determined according to the pressure-sinkage tests and shear tests conducted on the test bed. The effects of the operating parameters on the identification results were also analyzed. The results indicate a feasible scheme for future planetary subsurface exploration.

JHR Project: a future Material Testing Reactor working as an International user Facility: The key-role of instrumentation in support to the development of modern experimental capacity

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

Bignan, G.; Gonnier, C.; Lyoussi, A.

2015-07-01

Research and development on fuel and material behaviour under irradiation is a key issue for sustainable nuclear energy in order to meet specific needs by keeping the best level of safety. These needs mainly deal with a constant improvement of performances and safety in order to optimize the fuel cycle and hence to reach nuclear energy sustainable objectives. A sustainable nuclear energy requires a high level of performances in order to meet specific needs such as: - Pursuing improvement of the performances and safety of present and coming water cooled reactor technologies. This will require a continuous R and Dmore » support following a long-term trend driven by the plant life management, safety demonstration, flexibility and economics improvement. Experimental irradiations of structure materials are necessary to anticipate these material behaviours and will contribute to their optimisation. - Upgrading continuously nuclear fuel technology in present and future nuclear power plants to achieve better performances and to optimise the fuel cycle keeping the best level of safety. Fuel evolution for generation II, III and III+ is a key stake requiring developments, qualification tests and safety experiments to ensure the competitiveness and safety: experimental tests exploring the full range of fuel behaviour determine fuel stability limits and safety margins, as a major input for the fuel reliability analysis. To perform such accurate and innovative progress and developments, specific and ad hoc instrumentation, irradiation devices, measurement methods are necessary to be set up inside or beside the material testing reactor (MTR) core. These experiments require beforehand in situ and on line sophisticated measurements to accurately determine different key parameters such as thermal and fast neutron fluxes and nuclear heating in order to precisely monitor and control the conducted assays. The new Material Testing Reactor JHR (Jules Horowitz Reactor) currently under construction at CEA Cadarache research centre in the south of France will represent a major Research Infrastructure for scientific studies regarding material and fuel behavior under irradiation. It will also be devoted to medical isotopes production. Hence JHR will offer a real opportunity to perform R and D programs regarding needs above and hence will crucially contribute to the selection, optimization and qualification of these innovative materials and fuels. The JHR reactor objectives, principles and main characteristics associated to specific experimental devices associated to measurement techniques and methodology, their performances, their limitations and field of applications will be presented and discussed. (authors)« less

Methodological standards and interpretation of video-electroencephalography in adult control rodents. A TASK1-WG1 report of the AES/ILAE Translational Task Force of the ILAE.

PubMed

Kadam, Shilpa D; D'Ambrosio, Raimondo; Duveau, Venceslas; Roucard, Corinne; Garcia-Cairasco, Norberto; Ikeda, Akio; de Curtis, Marco; Galanopoulou, Aristea S; Kelly, Kevin M

2017-11-01

In vivo electrophysiological recordings are widely used in neuroscience research, and video-electroencephalography (vEEG) has become a mainstay of preclinical neuroscience research, including studies of epilepsy and cognition. Studies utilizing vEEG typically involve comparison of measurements obtained from different experimental groups, or from the same experimental group at different times, in which one set of measurements serves as "control" and the others as "test" of the variables of interest. Thus, controls provide mainly a reference measurement for the experimental test. Control rodents represent an undiagnosed population, and cannot be assumed to be "normal" in the sense of being "healthy." Certain physiological EEG patterns seen in humans are also seen in control rodents. However, interpretation of rodent vEEG studies relies on documented differences in frequency, morphology, type, location, behavioral state dependence, reactivity, and functional or structural correlates of specific EEG patterns and features between control and test groups. This paper will focus on the vEEG of standard laboratory rodent strains with the aim of developing a small set of practical guidelines that can assist researchers in the design, reporting, and interpretation of future vEEG studies. To this end, we will: (1) discuss advantages and pitfalls of common vEEG techniques in rodents and propose a set of recommended practices and (2) present EEG patterns and associated behaviors recorded from adult rats of a variety of strains. We will describe the defining features of selected vEEG patterns (brain-generated or artifactual) and note similarities to vEEG patterns seen in adult humans. We will note similarities to normal variants or pathological human EEG patterns and defer their interpretation to a future report focusing on rodent seizure patterns. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

Strawberry Phytochemicals Inhibit Azoxymethane/Dextran Sodium Sulfate-Induced Colorectal Carcinogenesis in Crj: CD-1 Mice

PubMed Central

Shi, Ni; Clinton, Steven K.; Liu, Zhihua; Wang, Yongquan; Riedl, Kenneth M.; Schwartz, Steven J.; Zhang, Xiaoli; Pan, Zui; Chen, Tong

2015-01-01

Human and experimental colon carcinogenesis are enhanced by a pro-inflammatory microenvironment. Pharmacologically driven chemopreventive agents and dietary variables are hypothesized to have future roles in the prevention of colon cancer by targeting these processes. The current study was designed to determine the ability of dietary lyophilized strawberries to inhibit inflammation-promoted colon carcinogenesis in a preclinical animal model. Mice were given a single i.p. injection of azoxymethane (10 mg kg−1 body weight). One week after injection, mice were administered 2% (w/v) dextran sodium sulfate in drinking water for seven days and then an experimental diet containing chemically characterized lyophilized strawberries for the duration of the bioassay. Mice fed control diet, or experimental diet containing 2.5%, 5.0% or 10.0% strawberries displayed tumor incidence of 100%, 64%, 75% and 44%, respectively (p < 0.05). The mechanistic studies demonstrate that strawberries reduced expression of proinflammatory mediators, suppressed nitrosative stress and decreased phosphorylation of phosphatidylinositol 3-kinase, Akt, extracellular signal-regulated kinase and nuclear factor kappa B. In conclusion, strawberries target proinflammatory mediators and oncogenic signaling for the preventive efficacies against colon carcinogenesis in mice. This works supports future development of fully characterized and precisely controlled functional foods for testing in human clinical trials for this disease. PMID:25763529

Antimicrobial Resources for Disinfection of Potable Water Systems for Future Spacecraft

NASA Technical Reports Server (NTRS)

Morford, Megan A.; Birmele, Michele; Roberts, Michael S.

2012-01-01

As human exploration adventures beyond low earth orbit, life support systems will require more innovation and research to become self-sustaining and durable. One major concern about future space travel is the ability to store and decontaminate water for consumption and hygiene. This project explores materials and technologies for possible use in future water systems without requiring point-of-use (POU) filtering or chemical additives such as iodine or silver that require multiple doses to remain effective. This experimentation tested the efficacy of a variety of antimicrobial materials against biofilm formation in a high shear CDC Biofilm Reactor (CBR) and some materials in a low shear Drip Flow Reactor (DFR) which(also utilizes ultra violet light emitting diodes (UVLEDs) as an antimicrobial resource. Most materials were tested in the CBR using the ASTM E 2562-07 1method involving the Pseudomonas aeruginosa and coupon samples that vary in their antimicrobial coatings and surface layer topographies. In a controlled environmental chamber (CEC), the CBR underwent a batch phase, continuous flow phase (CFP), and a harvest before analysis. The DFR portion of this experimentation was performed in order to assess the antimicrobial capabilities of ultraviolet-A LEDs (UV-A) in potable water systems. The ASTM E 2647-08 was modified in order to incorporate UV-A LEDs and to operate as a closed, re-circulating system. The modified DFR apparatus that was utilized contains 4 separate channels each of which contain 2 UV-A LEDs (1 chamber is masked off to serve as a control) and each channel is equipped with its own reservoir and peristaltic pump head. The 10 DFR runs discussed in this report include 4 initial experimental runs that contained blank microscope slides to test the UVA LEDs alone, 2 that incorporated solid silver coupons, 2 that utilized titanium dioxide (Ti02) coupons as a photocatalyst, and 2 runs that utilized silver coated acrylic slides. Both the CBR and DFR experiments were analyzed for microbial content via heterotrophic plate counts (HPC) and acridine orange direct counts (AODC). Ofthe materials used in the CBR, only two materials performed as antiicrobials under high shear conditions (a reduction of 5 or more logs) showing a>7 log reduction in viable microbes.

Progress with variable cycle engines

NASA Technical Reports Server (NTRS)

Westmoreland, J. S.

1980-01-01

The evaluation of components of an advanced propulsion system for a future supersonic cruise vehicle is discussed. These components, a high performance duct burner for thrust augmentation and a low jet noise coannular exhaust nozzle, are part of the variable stream control engine. An experimental test program involving both isolated component and complete engine tests was conducted for the high performance, low emissions duct burner with excellent results. Nozzle model tests were completed which substantiate the inherent jet noise benefit associated with the unique velocity profile possible of a coannular exhaust nozzle system on a variable stream control engine. Additional nozzle model performance tests have established high thrust efficiency levels at takeoff and supersonic cruise for this nozzle system. Large scale testing of these two critical components is conducted using an F100 engine as the testbed for simulating the variable stream control engine.

Multi-Physics Simulation of TREAT Kinetics using MAMMOTH

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

DeHart, Mark; Gleicher, Frederick; Ortensi, Javier

With the advent of next generation reactor systems and new fuel designs, the U.S. Department of Energy (DOE) has identified the need for the resumption of transient testing of nuclear fuels. DOE has decided that the Transient Reactor Test Facility (TREAT) at Idaho National Laboratory (INL) is best suited for future testing. TREAT is a thermal neutron spectrum nuclear test facility that is designed to test nuclear fuels in transient scenarios. These specific fuels transient tests range from simple temperature transients to full fuel melt accidents. The current TREAT core is driven by highly enriched uranium (HEU) dispersed in amore » graphite matrix (1:10000 U-235/C atom ratio). At the center of the core, fuel is removed allowing for the insertion of an experimental test vehicle. TREAT’s design provides experimental flexibility and inherent safety during neutron pulsing. This safety stems from the graphite in the driver fuel having a strong negative temperature coefficient of reactivity resulting from a thermal Maxwellian shift with increased leakage, as well as graphite acting as a temperature sink. Air cooling is available, but is generally used post-transient for heat removal. DOE and INL have expressed a desire to develop a simulation capability that will accurately model the experiments before they are irradiated at the facility, with an emphasis on effective and safe operation while minimizing experimental time and cost. At INL, the Multi-physics Object Oriented Simulation Environment (MOOSE) has been selected as the model development framework for this work. This paper describes the results of preliminary simulations of a TREAT fuel element under transient conditions using the MOOSE-based MAMMOTH reactor physics tool.« less

Characterizing the Response of Composite Panels to a Pyroshock Induced Environment Using Design of Experiments Methodology

NASA Technical Reports Server (NTRS)

Parsons, David S.; Ordway, David; Johnson, Kenneth

2013-01-01

This experimental study seeks to quantify the impact various composite parameters have on the structural response of a composite structure in a pyroshock environment. The prediction of an aerospace structure's response to pyroshock induced loading is largely dependent on empirical databases created from collections of development and flight test data. While there is significant structural response data due to pyroshock induced loading for metallic structures, there is much less data available for composite structures. One challenge of developing a composite pyroshock response database as well as empirical prediction methods for composite structures is the large number of parameters associated with composite materials. This experimental study uses data from a test series planned using design of experiments (DOE) methods. Statistical analysis methods are then used to identify which composite material parameters most greatly influence a flat composite panel's structural response to pyroshock induced loading. The parameters considered are panel thickness, type of ply, ply orientation, and pyroshock level induced into the panel. The results of this test will aid in future large scale testing by eliminating insignificant parameters as well as aid in the development of empirical scaling methods for composite structures' response to pyroshock induced loading.

Characterizing the Response of Composite Panels to a Pyroshock Induced Environment using Design of Experiments Methodology

NASA Technical Reports Server (NTRS)

Parsons, David S.; Ordway, David O.; Johnson, Kenneth L.

2013-01-01

This experimental study seeks to quantify the impact various composite parameters have on the structural response of a composite structure in a pyroshock environment. The prediction of an aerospace structure's response to pyroshock induced loading is largely dependent on empirical databases created from collections of development and flight test data. While there is significant structural response data due to pyroshock induced loading for metallic structures, there is much less data available for composite structures. One challenge of developing a composite pyroshock response database as well as empirical prediction methods for composite structures is the large number of parameters associated with composite materials. This experimental study uses data from a test series planned using design of experiments (DOE) methods. Statistical analysis methods are then used to identify which composite material parameters most greatly influence a flat composite panel's structural response to pyroshock induced loading. The parameters considered are panel thickness, type of ply, ply orientation, and pyroshock level induced into the panel. The results of this test will aid in future large scale testing by eliminating insignificant parameters as well as aid in the development of empirical scaling methods for composite structures' response to pyroshock induced loading.

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

Zhang, Chao; Xu, Jun; Cao, Lei

The electrodes of lithium-ion batteries (LIB) are known to be brittle and to fail earlier than the separators during an external crush event. Thus, the understanding of mechanical failure mechanism for LIB electrodes (anode and cathode) is critical for the safety design of LIB cells. In this paper, we present experimental and numerical studies on the constitutive behavior and progression of failure in LIB electrodes. Mechanical tests were designed and conducted to evaluate the constitutive properties of porous electrodes. Constitutive models were developed to describe the stress-strain response of electrodes under uniaxial tensile and compressive loads. The failure criterion andmore » a damage model were introduced to model their unique tensile and compressive failure behavior. The failure mechanism of LIB electrodes was studied using the blunt rod test on dry electrodes, and numerical models were built to simulate progressive failure. The different failure processes were examined and analyzed in detail numerically, and correlated with experimentally observed failure phenomena. Finally, the test results and models improve our understanding of failure behavior in LIB electrodes, and provide constructive insights on future development of physics-based safety design tools for battery structures under mechanical abuse.« less

Hiding the Tobacco Power Wall Reduces Cigarette Smoking Risk in Adolescents: Using an Experimental Convenience Store to Assess Tobacco Regulatory Options at Retail Point-of-Sale

PubMed Central

Shadel, William G.; Martino, Steven; Setodji, Claude; Scharf, Deborah; Kusuke, Daniela; Sicker, Angela; Gong, Min

2015-01-01

Objectives This experiment tested whether changing the location or visibility of the tobacco power wall in a life sized replica of a convenience store had any effect on adolescents’ susceptibility to future cigarette smoking. Methods The study was conducted in the RAND StoreLab (RSL), a life sized replica of a convenience store that was developed to experimentally evaluate how changing aspects of tobacco advertising displays in retail point-of-sale environments influences tobacco use risk and behavior. A randomized, between-subjects experimental design with three conditions that varied the location or visibility of the tobacco power wall within the RSL was used. The conditions were: cashier (the tobacco power wall was located in its typical position behind the cash register counter); sidewall (the tobacco power wall was located on a sidewall away from the cash register); or hidden (the tobacco power wall was located behind the cashier but was hidden behind an opaque wall). The sample included 241 adolescents. Results Hiding the tobacco power wall significantly reduced adolescents’ susceptibility to future cigarette smoking compared to leaving it exposed (i.e., the cashier condition; p = .02). Locating the tobacco power wall on a sidewall away from the cashier had no effect on future cigarette smoking susceptibility compared to the cashier condition (p = 0.80). Conclusions Hiding the tobacco power wall at retail point-of-sale locations is a strong regulatory option for reducing the impact of the retail environment on cigarette smoking risk in adolescents. PMID:26598502

Exploring Alternate Processes Contributing to the Association Between Maternal Smoking and the Smoking Behavior Among Young Adult Offspring

PubMed Central

2013-01-01

Introduction: Maternal smoking during pregnancy (MSP) is a known risk factor for regular smoking in young adulthood and may pose a risk independently of mother’s lifetime smoking. The processes through which MSP exerts this influence are unknown but may occur through greater smoking quantity and frequency following initiation early in adolescence or increased sensitivity to nicotine dependence (ND) at low levels of smoking. Methods: This study used path analysis to investigate adolescent smoking quantity, smoking frequency, and ND as potential simultaneous mediating pathways through which MSP and mother’s lifetime smoking (whether she has ever smoked) increase the risk of smoking in young adulthood among experimenters (at baseline, <100 cigarettes/lifetime) and current smokers (>100 cigarettes/lifetime). Results: For experimenters, MSP was directly associated with more frequent young adult smoking and was not mediated by adolescent smoking behavior or ND. Independently of MSP, the effect of mother’s lifetime smoking was fully mediated through frequent smoking and was heightened ND during adolescence. Controlling for MSP eliminated a previously observed direct association between mother’s lifetime smoking and future smoking among experimenters. For current smokers, only prior smoking behavior was associated with future smoking frequency. Conclusions: These results seem to rule out sensitivity to ND and increased smoking behavior as contributing pathways of MSP. Further, the impact of MSP on young adult smoking extends beyond that of having an ever-smoking mother. Future work should test other possible mediators; for example, MSP-related epigenetic changes or gene variants influencing the brain’s nicotine response. PMID:23766342

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

Curceanu, C.; Bragadireanu, M.; Sirghi, D.

The Pauli Exclusion Principle (PEP) is one of the basic principles of modern physics and, even if there are no compelling reasons to doubt its validity, it is still debated today because an intuitive, elementary explanation is still missing, and because of its unique stand among the basic symmetries of physics. We present an experimental test of the validity of the Pauli Exclusion Principle for electrons based on a straightforward idea put forward a few years ago by Ramberg and Snow (E. Ramberg and G. A. Snow 1990 Phys. Lett. B 238 438). We performed a very accurate search ofmore » X-rays from the Pauli-forbidden atomic transitions of electrons in the already filled 1S shells of copper atoms. Although the experiment has a very simple structure, it poses deep conceptual and interpretational problems. Here we describe the experimental method and recent experimental results interpreted as an upper limit for the probability to violate the Pauli Exclusion Principle. We also present future plans to upgrade the experimental apparatus.« less

Unique Challenges Testing SDRs for Space

NASA Technical Reports Server (NTRS)

Chelmins, David; Downey, Joseph A.; Johnson, Sandra K.; Nappier, Jennifer M.

2013-01-01

This paper describes the approach used by the Space Communication and Navigation (SCaN) Testbed team to qualify three Software Defined Radios (SDR) for operation in space and the characterization of the platform to enable upgrades on-orbit. The three SDRs represent a significant portion of the new technologies being studied on board the SCAN Testbed, which is operating on an external truss on the International Space Station (ISS). The SCaN Testbed provides experimenters an opportunity to develop and demonstrate experimental waveforms and applications for communication, networking, and navigation concepts and advance the understanding of developing and operating SDRs in space. Qualifying a Software Defined Radio for the space environment requires additional consideration versus a hardware radio. Tests that incorporate characterization of the platform to provide information necessary for future waveforms, which might exercise extended capabilities of the hardware, are needed. The development life cycle for the radio follows the software development life cycle, where changes can be incorporated at various stages of development and test. It also enables flexibility to be added with minor additional effort. Although this provides tremendous advantages, managing the complexity inherent in a software implementation requires a testing beyond the traditional hardware radio test plan. Due to schedule and resource limitations and parallel development activities, the subsystem testing of the SDRs at the vendor sites was primarily limited to typical fixed transceiver type of testing. NASA s Glenn Research Center (GRC) was responsible for the integration and testing of the SDRs into the SCaN Testbed system and conducting the investigation of the SDR to advance the technology to be accepted by missions. This paper will describe the unique tests that were conducted at both the subsystem and system level, including environmental testing, and present results. For example, test waveforms were developed to measure the gain of the transmit system across the tunable frequency band. These were used during thermal vacuum testing to enable characterization of the integrated system in the wide operational temperature range of space. Receive power indicators were used for Electromagnetic Interference tests (EMI) to understand the platform s susceptibility to external interferers independent of the waveform. Additional approaches and lessons learned during the SCaN Testbed subsystem and system level testing will be discussed that may help future SDR integrators

Unique Challenges Testing SDRs for Space

NASA Technical Reports Server (NTRS)

Johnson, Sandra; Chelmins, David; Downey, Joseph; Nappier, Jennifer

2013-01-01

This paper describes the approach used by the Space Communication and Navigation (SCaN) Testbed team to qualify three Software Defined Radios (SDR) for operation in space and the characterization of the platform to enable upgrades on-orbit. The three SDRs represent a significant portion of the new technologies being studied on board the SCAN Testbed, which is operating on an external truss on the International Space Station (ISS). The SCaN Testbed provides experimenters an opportunity to develop and demonstrate experimental waveforms and applications for communication, networking, and navigation concepts and advance the understanding of developing and operating SDRs in space. Qualifying a Software Defined Radio for the space environment requires additional consideration versus a hardware radio. Tests that incorporate characterization of the platform to provide information necessary for future waveforms, which might exercise extended capabilities of the hardware, are needed. The development life cycle for the radio follows the software development life cycle, where changes can be incorporated at various stages of development and test. It also enables flexibility to be added with minor additional effort. Although this provides tremendous advantages, managing the complexity inherent in a software implementation requires a testing beyond the traditional hardware radio test plan. Due to schedule and resource limitations and parallel development activities, the subsystem testing of the SDRs at the vendor sites was primarily limited to typical fixed transceiver type of testing. NASA's Glenn Research Center (GRC) was responsible for the integration and testing of the SDRs into the SCaN Testbed system and conducting the investigation of the SDR to advance the technology to be accepted by missions. This paper will describe the unique tests that were conducted at both the subsystem and system level, including environmental testing, and present results. For example, test waveforms were developed to measure the gain of the transmit system across the tunable frequency band. These were used during thermal vacuum testing to enable characterization of the integrated system in the wide operational temperature range of space. Receive power indicators were used for Electromagnetic Interference tests (EMI) to understand the platform's susceptibility to external interferers independent of the waveform. Additional approaches and lessons learned during the SCaN Testbed subsystem and system level testing will be discussed that may help future SDR integrators.

A toolbox for computing pebble shape and roundness indexes: experimental tests and recommendations for future applications.

NASA Astrophysics Data System (ADS)

Cassel, M.; Piegay, H.; Lave, J.

2016-12-01

Pebble rounding caused by attrition is, beside chemical dissolution, breakage, and grain size segregation, one of the key processes controlling bedload downstream fining in rivers. Downstream changes in pebble geometry is subject of consideration since Aristotle (Krynine, 1960) and its measurement represent a challenge since the end of 19th century, leading to a long standing debate (Blott and Pye, 2008). A toolbox developed by Roussillon et al. (2009) operate on automatic computation of several shape and roundness indexes from images of 2D projection plan of pebbles disposed on a one meter square red board. In order to promote the tool for future applications, we tested the effects of pebble position on board, of picture resolution and treatment on three shape and roundness indexes. We also compared the downstream patterns of these indexes on two pebble samples of the same lithology collected on the Progo River (Indonesia) based on field observations (i) and experimentation (ii). Shape and roundness were measured on (i) 8 sites distributed over a distance of 36 km along the river, and (ii) ten times on a set of particules collected on the Progo spring and transported in an annular flume over the same distance. This travel distance was monitored using passive low frequency RFID system. Results show that pebble position does not have a significant effect on shape and roundness indexes but these indexes are sensible to picture resolutions and treatments so that a clear protocol must be considered for avoiding any observer bias. Downstream changes in roundness indexes are very similar in field and experimental conditions, while abrasion environments are distinct. Discontinuities observed in downstream river pattern but not in experimental one underlined changes in Progo River pebble roundness are probably caused by sediment supplied from tributaries or bank erosion. These results highlight the toolbox potential for diagnosing river systems function.

PIV measurements of airflow past multiple cylinders

NASA Astrophysics Data System (ADS)

Wodziak, Waldemar; Sobczyk, Jacek

2018-06-01

Flow characteristics in vicinity of six circular cylinders aligned inline was investigated experimentally by means of PIV method. Experiments were conducted in a low speed closed circuit wind tunnel. Inflow velocity was 1.2 m/s which corresponds to Re=1600 based on the cylinder diameter. Spacing ratio between cylinders L/D was 1.5. Instantaneous and averaged velocity fields were presented. Experiments were designed in order to use their results as a test case for future numerical calculations.

Flight Tests of Pilotage Error in Area Navigation with Vertical Guidance: Effects of Navigation Procedural Complexity

DTIC Science & Technology

1974-08-01

contributed substantially to the planning of the flight course used in this study and in the preparation of this report. Assistance in business matters has...CONTENTS Page INTRODUCTION 1 METHOD 5 Subjects 5 Equipment Experimental Plan 8 Procedure 14 Performance Assessment 17 Statistical Treatment 19 RESULTS...implementation of RNAV service. These documents provide the basis for future RNAV planning both procedurally and quantitatively. At the heart of the

Scaling Studies for Advanced High Temperature Reactor Concepts, Final Technical Report: October 2014—December 2017

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

Woods, Brian; Gutowska, Izabela; Chiger, Howard

Computer simulations of nuclear reactor thermal-hydraulic phenomena are often used in the design and licensing of nuclear reactor systems. In order to assess the accuracy of these computer simulations, computer codes and methods are often validated against experimental data. This experimental data must be of sufficiently high quality in order to conduct a robust validation exercise. In addition, this experimental data is generally collected at experimental facilities that are of a smaller scale than the reactor systems that are being simulated due to cost considerations. Therefore, smaller scale test facilities must be designed and constructed in such a fashion tomore » ensure that the prototypical behavior of a particular nuclear reactor system is preserved. The work completed through this project has resulted in scaling analyses and conceptual design development for a test facility capable of collecting code validation data for the following high temperature gas reactor systems and events— 1. Passive natural circulation core cooling system, 2. pebble bed gas reactor concept, 3. General Atomics Energy Multiplier Module reactor, and 4. prismatic block design steam-water ingress event. In the event that code validation data for these systems or events is needed in the future, significant progress in the design of an appropriate integral-type test facility has already been completed as a result of this project. Where applicable, the next step would be to begin the detailed design development and material procurement. As part of this project applicable scaling analyses were completed and test facility design requirements developed. Conceptual designs were developed for the implementation of these design requirements at the Oregon State University (OSU) High Temperature Test Facility (HTTF). The original HTTF is based on a ¼-scale model of a high temperature gas reactor concept with the capability for both forced and natural circulation flow through a prismatic core with an electrical heat source. The peak core region temperature capability is 1400°C. As part of this project, an inventory of test facilities that could be used for these experimental programs was completed. Several of these facilities showed some promise, however, upon further investigation it became clear that only the OSU HTTF had the power and/or peak temperature limits that would allow for the experimental programs envisioned herein. Thus the conceptual design and feasibility study development focused on examining the feasibility of configuring the current HTTF to collect validation data for these experimental programs. In addition to the scaling analyses and conceptual design development, a test plan was developed for the envisioned modified test facility. This test plan included a discussion on an appropriate shakedown test program as well as the specific matrix tests. Finally, a feasibility study was completed to determine the cost and schedule considerations that would be important to any test program developed to investigate these designs and events.« less

The Confrontation between General Relativity and Experiment.

PubMed

Will, Clifford M

2014-01-01

The status of experimental tests of general relativity and of theoretical frameworks for analyzing them is reviewed and updated. Einstein's equivalence principle (EEP) is well supported by experiments such as the Eötvös experiment, tests of local Lorentz invariance and clock experiments. Ongoing tests of EEP and of the inverse square law are searching for new interactions arising from unification or quantum gravity. Tests of general relativity at the post-Newtonian level have reached high precision, including the light deflection, the Shapiro time delay, the perihelion advance of Mercury, the Nordtvedt effect in lunar motion, and frame-dragging. Gravitational wave damping has been detected in an amount that agrees with general relativity to better than half a percent using the Hulse-Taylor binary pulsar, and a growing family of other binary pulsar systems is yielding new tests, especially of strong-field effects. Current and future tests of relativity will center on strong gravity and gravitational waves.

Academic Achievement from Using the Learning Medium Via a Tablet Device Based on Multiple Intelligences in Grade 1 Elementary Student.

PubMed

Nuallaong, Winitra; Nuallaong, Thanya; Preechadirek, Nongluck

2015-04-01

To measure academic achievement of the multiple intelligence-based learning medium via a tablet device. This is a quasi-experimental research study (non-randomized control group pretest-posttest design) in 62 grade 1 elementary students (33 males and 29 females). Thirty-one students were included in an experimental group using purposive sampling by choosing a student who had highest multiple intelligence test scores in logical-mathematic. Then, this group learned by the new learning medium via a tablet which the application matched to logical-mathematic multiple intelligence. Another 31 students were included in a control group using simple random sampling and then learning by recitation. Both groups did pre-test and post-test vocabulary. Thirty students in the experimental group and 24 students in the control group increased post-test scores (odds ratio = 8.75). Both groups made significant increasing in post-test scores. The experimental group increased 9.07 marks (95% CI 8.20-9.93) significantly higher than the control group which increased 4.39 marks (95% CI 3.06-5.72) (t = -6.032, df = 51.481, p < 0.001). Although learning from either multiple intelligence-based learning medium via a tablet or recitation can contribute academic achievement, learningfrom the new medium contributed more achievement than recitation. The new learning medium group had higher post-test scores 8.75 times than the recitation group. Therefore, the new learning medium is more effective than the traditional recitation in terms of academic achievement. This study has limitations because samples came from the same school. However, the previous study in Thailand did notfind a logical-mathematical multiple intelligence difference among schools. In the future, long-term research to find how the new learning medium affects knowledge retention will support the advantage for life-long learning.

Applicability of a new robotic walking aid in a patient with cerebral palsy. Case report.

PubMed

Smania, N; Gandolfi, M; Marconi, V; Calanca, A; Geroin, C; Piazza, S; Bonetti, P; Fiorini, P; Cosentino, A; Capelli, C; Conte, D; Bendinelli, M; Munari, D; Ianes, P; Fiaschi, A; Picelli, A

2012-03-01

Gait training with the help of assistive technological devices is an innovative field of research in neurological rehabilitation. Most of the available gait training devices do not allow free movement in the environment, which would be the most suitable natural and motivating condition for training children with neurological gait impairment. To evaluate the potential applicability of a new robotic walking aid as a tool for gait training in non-ambulatory children with Cerebral Palsy. Single case study Outpatient regimen A 11-years-old child unable to stand and walk independently as a result of spastic tetraplegic cerebral palsy (CP). The experimental device was a newly actuated version of a dynamic combined walking and standing aid (NF-Walker®) available in the market which was modified by means of two pneumatic artificial muscles driven by a foot-switch inserted in the shoes. The child was tested at baseline (while maintaining the standing position aided by the non-actuated NF-Walker®) and in the experimental condition (while using the actuated robotic aid). The outcome measures were: 2-minute walking test, 10-metre walking test, respiratory and heart parameters, energy cost of locomotion. At baseline, the child was unable to perform any autonomous form of locomotion. When assisted by the actuated aid (i.e. during the experimental condition), the child was successful in moving around in his environment. His performance was 19.63 m in the 2-minute walking test and 64 s in the 10-metre walking test. Respiratory and heart parameters were higher than healthy age-matched children both at baseline and in the experimental condition. The energy cost of gait, which was not valuable in the baseline condition, was significantly higher than normality during the experimental condition. The new robotic walking aid may help children suffering from CP with severe impairment of gait to move around in their environment. This new robotic walking device may have a potential impact in stimulating the development and in training of gait in children with neurological gait impairment. Future studies are warranted in order to test this hypothesis.

Promises and pitfalls of Web-based experimentation in the advance of replicable psychological science: A reply to Plant (2015).

PubMed

van Steenbergen, Henk; Bocanegra, Bruno R

2016-12-01

In a recent letter, Plant (2015) reminded us that proper calibration of our laboratory experiments is important for the progress of psychological science. Therefore, carefully controlled laboratory studies are argued to be preferred over Web-based experimentation, in which timing is usually more imprecise. Here we argue that there are many situations in which the timing of Web-based experimentation is acceptable and that online experimentation provides a very useful and promising complementary toolbox to available lab-based approaches. We discuss examples in which stimulus calibration or calibration against response criteria is necessary and situations in which this is not critical. We also discuss how online labor markets, such as Amazon's Mechanical Turk, allow researchers to acquire data in more diverse populations and to test theories along more psychological dimensions. Recent methodological advances that have produced more accurate browser-based stimulus presentation are also discussed. In our view, online experimentation is one of the most promising avenues to advance replicable psychological science in the near future.

Evidence of Standing Waves in Arc Jet Nozzle Flow

NASA Technical Reports Server (NTRS)

Driver, David M.; Hartman, Joe; Philippidis, Daniel; Noyes, Eric; Hui, Frank; Terrazas-Salinas, Imelda

2017-01-01

Waves spawned by the nozzle in the NASA Ames 60 MW Interaction Heating Facility arc jet were experimentally observed in pressure surveys at the exit of the nozzle. The waves have been seen in past CFD simulations, but were away from the region where models were tested (for the existing nozzles). However, a recent test series with a new nozzle extension (229 mm exit diameter) revealed that these waves intersect the centerline of the jet in a region where it is desirable to put test articles, and that the waves may be contributing to non-uniform recession behavior seen in Teflon (trademark) sublimation test articles tested in this new nozzle. It is reasonable to assume the ablation recession of thermal protection models will also be nonuniform due to exposure to these waves. This work shows that ablation response is sensitive to the location of test samples in the free jet relative to the location of the wave interaction, and that the issues with these waves can be avoided by choosing an optimum position for a test article in the free jet. This work describes the experimental observations along with the CFD simulations that have identified the waves emanating from the nozzle, as well as the instrumentation used to detect them. The work describes a recommended solution, derived by CFD analysis, which if implemented, should significantly reduce these flow disturbance and pressure anomalies in future nozzles.

Note: Inter-satellite laser range-rate measurement by using digital phase locked loop.

PubMed

Liang, Yu-Rong; Duan, Hui-Zong; Xiao, Xin-Long; Wei, Bing-Bing; Yeh, Hsien-Chi

2015-01-01

This note presents an improved high-resolution frequency measurement system dedicated for the inter-satellite range-rate monitoring that could be used in the future's gravity recovery mission. We set up a simplified common signal test instead of the three frequencies test. The experimental results show that the dominant noises are the sampling time jitter and the thermal drift of electronic components, which can be reduced by using the pilot-tone correction and passive thermal control. The improved noise level is about 10(-8) Hz/Hz(1/2)@0.01Hz, limited by the signal-to-noise ratio of the sampling circuit.

Note: Inter-satellite laser range-rate measurement by using digital phase locked loop

NASA Astrophysics Data System (ADS)

Liang, Yu-Rong; Duan, Hui-Zong; Xiao, Xin-Long; Wei, Bing-Bing; Yeh, Hsien-Chi

2015-01-01

This note presents an improved high-resolution frequency measurement system dedicated for the inter-satellite range-rate monitoring that could be used in the future's gravity recovery mission. We set up a simplified common signal test instead of the three frequencies test. The experimental results show that the dominant noises are the sampling time jitter and the thermal drift of electronic components, which can be reduced by using the pilot-tone correction and passive thermal control. The improved noise level is about 10-8 Hz/Hz1/2@0.01Hz, limited by the signal-to-noise ratio of the sampling circuit.

Propellant material compatibility program and results

NASA Technical Reports Server (NTRS)

Toth, L. R.; Cannon, W. A.; Coulbert, C. D.; Long, H. R.

1976-01-01

The effects of long-term (up to 10 years) contact of inert materials with earth-storable propellants were studied for the purpose of designing chemical propulsion system components that can be used for current as well as future planetary spacecraft. The primary experimental work, and results to date are reported. Investigations include the following propellants: hydrazine, hydrazine-hydrazine nitrate blends, monomethyl-hydrazine, and nitrogen tetroxide. Materials include: aluminum alloys, corrosion-resistant steels, and titanium alloys. More than 700 test specimen capsules were placed in long-term storage testing at 43 C in the special material compatibility facility. Material ratings relative to the 10-year requirement have been assigned.

Reusable Metallic Thermal Protection Systems Development

NASA Technical Reports Server (NTRS)

Blosser, Max L.; Martin, Carl J.; Daryabeigi, Kamran; Poteet, Carl C.

1998-01-01

Metallic thermal protection systems (TPS) are being developed to help meet the ambitious goals of future reusable launch vehicles. Recent metallic TPS development efforts at NASA Langley Research Center are described. Foil-gage metallic honeycomb coupons, representative of the outer surface of metallic TPS were subjected to low speed impact, hypervelocity impact, rain erosion, and subsequent arcjet exposure. TPS panels were subjected to thermal vacuum, acoustic, and hot gas flow testing. Results of the coupon and panel tests are presented. Experimental and analytical tools are being developed to characterize and improve internal insulations. Masses of metallic TPS and advanced ceramic tile and blanket TPS concepts are compared for a wide range of parameters.

Dynamic testing system for hybrid magneto-optical recording

NASA Astrophysics Data System (ADS)

Chen, Lu; Xu, Wendong; Fan, Yongtao; Zhu, Qing

2008-12-01

Hybrid Magneto-Optical Recording is a potential data storage technology in the future informational society. To construct a research platform for hybrid recording, a dynamic testing system is designed and built in this paper, in which 406.7nm blue laser is used for recording and 655nm red laser for focus servo. With high modularization, the computer serves as the control core for the laser external modulation, focus servo, and sample plate spinning. Each module and its function are discussed in detail in the paper. Experimental results are also given to verify the stable and smooth performance of the system, in which the key obstacle, vibration noise, is successfully surmounted.

Approach and Instrument Placement Validation

NASA Technical Reports Server (NTRS)

Ator, Danielle

2005-01-01

The Mars Exploration Rovers (MER) from the 2003 flight mission represents the state of the art technology for target approach and instrument placement on Mars. It currently takes 3 sols (Martian days) for the rover to place an instrument on a designated rock target that is about 10 to 20 m away. The objective of this project is to provide an experimentally validated single-sol instrument placement capability to future Mars missions. After completing numerous test runs on the Rocky8 rover under various test conditions, it has been observed that lighting conditions, shadow effects, target features and the initial target distance have an effect on the performance and reliability of the tracking software. Additional software validation testing will be conducted in the months to come.

Delay of Gratification, Delay Discounting and their Associations with Age, Episodic Future Thinking, and Future Time Perspective

PubMed Central

Göllner, Lars M.; Ballhausen, Nicola; Kliegel, Matthias; Forstmeier, Simon

2018-01-01

The delay of gratification (DoG) in children is widely investigated with an experimental procedure originally called the “marshmallow test,” whereas the studies on self-regulation (SR) in adolescents and adults usually use self-report questionnaires. Delay discounting (DD) measures simplify the DoG procedure and focus on monetary rewards. The aim of this study was to investigate age differences in DoG and DD from childhood to old age using a test that is suitable for both children and adults. Furthermore, investigations were conducted on the association between DoG/DD and two future orientation constructs [future time perspective (FTP) and episodic future thinking (EFT)] as well as age differences in these constructs. Participants from five age groups (9–14, 18–25, 35–55, 65–80, 80+) participated in the study (N = 96). While we found no age difference for DoG, DD was the lowest [i.e., self-control (SC) was the highest] in young/middle adults; however, it was the highest (i.e., SC was the lowest) in children and old/oldest adults. Furthermore, we found significant age differences for DD and FTP. As predicted, there were strong correlations between DoG and FTP and between DD and FTP, but not between DoG/DD and EFT. These results indicate that age differences in SR vary across the measures used. Individuals who generally think and act in a future-oriented manner have a stronger ability to delay gratification. PMID:29422875

Design, Modeling, Fabrication, and Evaluation of the Air Amplifier for Improved Detection of Biomolecules by Electrospray Ionization Mass Spectrometry

PubMed Central

Robichaud, Guillaume; Dixon, R. Brent; Potturi, Amarnatha S.; Cassidy, Dan; Edwards, Jack R.; Sohn, Alex; Dow, Thomas A.; Muddiman, David C.

2010-01-01

Through a multi-disciplinary approach, the air amplifier is being evolved as a highly engineered device to improve detection limits of biomolecules when using electrospray ionization. Several key aspects have driven the modifications to the device through experimentation and simulations. We have developed a computer simulation that accurately portrays actual conditions and the results from these simulations are corroborated by the experimental data. These computer simulations can be used to predict outcomes from future designs resulting in a design process that is efficient in terms of financial cost and time. We have fabricated a new device with annular gap control over a range of 50 to 70 μm using piezoelectric actuators. This has enabled us to obtain better aerodynamic performance when compared to the previous design (2× more vacuum) and also more reproducible results. This is allowing us to study a broader experimental space than the previous design which is critical in guiding future directions. This work also presents and explains the principles behind a fractional factorial design of experiments methodology for testing a large number of experimental parameters in an orderly and efficient manner to understand and optimize the critical parameters that lead to obtain improved detection limits while minimizing the number of experiments performed. Preliminary results showed that several folds of improvements could be obtained for certain condition of operations (up to 34 folds). PMID:21499524

Active SAmpling Protocol (ASAP) to Optimize Individual Neurocognitive Hypothesis Testing: A BCI-Inspired Dynamic Experimental Design.

PubMed

Sanchez, Gaëtan; Lecaignard, Françoise; Otman, Anatole; Maby, Emmanuel; Mattout, Jérémie

2016-01-01

The relatively young field of Brain-Computer Interfaces has promoted the use of electrophysiology and neuroimaging in real-time. In the meantime, cognitive neuroscience studies, which make extensive use of functional exploration techniques, have evolved toward model-based experiments and fine hypothesis testing protocols. Although these two developments are mostly unrelated, we argue that, brought together, they may trigger an important shift in the way experimental paradigms are being designed, which should prove fruitful to both endeavors. This change simply consists in using real-time neuroimaging in order to optimize advanced neurocognitive hypothesis testing. We refer to this new approach as the instantiation of an Active SAmpling Protocol (ASAP). As opposed to classical (static) experimental protocols, ASAP implements online model comparison, enabling the optimization of design parameters (e.g., stimuli) during the course of data acquisition. This follows the well-known principle of sequential hypothesis testing. What is radically new, however, is our ability to perform online processing of the huge amount of complex data that brain imaging techniques provide. This is all the more relevant at a time when physiological and psychological processes are beginning to be approached using more realistic, generative models which may be difficult to tease apart empirically. Based upon Bayesian inference, ASAP proposes a generic and principled way to optimize experimental design adaptively. In this perspective paper, we summarize the main steps in ASAP. Using synthetic data we illustrate its superiority in selecting the right perceptual model compared to a classical design. Finally, we briefly discuss its future potential for basic and clinical neuroscience as well as some remaining challenges.

Performance of Low Temperature Electrolytes in Experimental and Prototype Li-Ion Cells

NASA Technical Reports Server (NTRS)

Smart, M. C.; Ratnakumar, B. V.; Whitcanack, L. D.

2007-01-01

Due to their attractive properties and proven success, Li-ion batteries have become identified as the battery chemistry of choice for a number of future NASA missions. A number of these applications would be greatly benefited by improved performance of Li-ion technology over a wider operating temperature range, especially at low temperatures, such as future ESMD missions. In many cases, these technology improvements may be mission enabling, and at the very least mission enhancing. In addition to aerospace applications, the DoE has interest in developing advanced Li-ion batteries that can operate over a wide temperature range to enable terrestrial HEV applications. Thus, our focus at JPL in recent years has been to extend the operating temperature range of Li-ion batteries, especially at low temperatures. To accomplish this, the main focus of the research has been devoted to developing improved lithium-ion conducting electrolytes. In the present paper, we would like to present some of the results we have obtained with ethylene carbonate-based electrolytes optimized for low temperature in experimental MCMB-LiNixCo1_x0 2 cells. In addition to obtaining discharge and charge rate performance data at various temperatures, electrochemical measurements were performed on individual electrodes (made possible by the incorporation of Li reference electrodes), including EIS, linear polarization and Tafel polarization measurements. The combination of techniques enables the elucidation of various trends associated with electrolyte composition. In addition to investigating the behavior in experimental cells, the performance of many promising low temperature electrolytes was demonstrated in large capacity, aerospace quality Li-ion prototype cells. These cells were subjected to a number of performance tests, including discharge rate characterization, charge rate characterization, cycle life performance at various temperatures, and power characterization tests.

Explaining dark matter and B decay anomalies with an L μ - L τ model

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

Altmannshofer, Wolfgang; Gori, Stefania; Profumo, Stefano

We present a dark sector model based on gauging the L μ - L τ symmetry that addresses anomalies in b→ sμ +μ - decays and that features a particle dark matter candidate. The dark matter particle candidate is a vector-like Dirac fermion coupled to the Z' gauge boson of the L μ - L τ symmetry. We compute the dark matter thermal relic density, its pair-annihilation cross section, and the loop-suppressed dark matter-nucleon scattering cross section, and compare our predictions with current and future experimental results. We demonstrate that after taking into account bounds from Bs meson oscillations, darkmore » matter direct detection, and the CMB, the model is highly predictive: B physics anomalies and a viable particle dark matter candidate, with a mass of ~ (5 - 23) GeV, can be accommodated only in a tightly-constrained region of parameter space, with sharp predictions for future experimental tests. The viable region of parameter space expands if the dark matter is allowed to have L μ - L τ charges that are smaller than those of the SM leptons.« less

Explaining dark matter and B decay anomalies with an L μ - L τ model

DOE PAGES

Altmannshofer, Wolfgang; Gori, Stefania; Profumo, Stefano; ...

2016-12-20

We present a dark sector model based on gauging the L μ - L τ symmetry that addresses anomalies in b→ sμ +μ - decays and that features a particle dark matter candidate. The dark matter particle candidate is a vector-like Dirac fermion coupled to the Z' gauge boson of the L μ - L τ symmetry. We compute the dark matter thermal relic density, its pair-annihilation cross section, and the loop-suppressed dark matter-nucleon scattering cross section, and compare our predictions with current and future experimental results. We demonstrate that after taking into account bounds from Bs meson oscillations, darkmore » matter direct detection, and the CMB, the model is highly predictive: B physics anomalies and a viable particle dark matter candidate, with a mass of ~ (5 - 23) GeV, can be accommodated only in a tightly-constrained region of parameter space, with sharp predictions for future experimental tests. The viable region of parameter space expands if the dark matter is allowed to have L μ - L τ charges that are smaller than those of the SM leptons.« less

Ultrasonic High-Temperature Sensors: Past Experiments and Prospects for Future Use

NASA Astrophysics Data System (ADS)

Laurie, M.; Magallon, D.; Rempe, J.; Wilkins, C.; Pierre, J.; Marquié, C.; Eymery, S.; Morice, R.

2010-09-01

Ultrasonic thermometry sensors (UTS) have been intensively studied in the past to measure temperatures from 2080 K to 3380 K. This sensor, which uses the temperature dependence of the acoustic velocity in materials, was developed for experiments in extreme environments. Its major advantages, which are (a) capability of measuring a temperature profile from multiple sensors on a single probe and (b) measurement near the sensor material melting point, can be of great interest when dealing with on-line monitoring of high-temperature safety tests. Ultrasonic techniques were successfully applied in several severe accident related experiments. With new developments of alternative materials, this instrument may be used in a wide range of experimental areas where robustness and compactness are required. Long-term irradiation experiments of nuclear fuel to extremely high burn-ups could benefit from this previous experience. After an overview of UTS technology, this article summarizes experimental work performed to improve the reliability of these sensors. The various designs, advantages, and drawbacks are outlined and future prospects for long-term high-temperature irradiation experiments are discussed.

Multi-Evaporator Miniature Loop Heat Pipe for Small Spacecraft Thermal Control. Part 2; Validation Results

NASA Technical Reports Server (NTRS)

Ku, Jentung; Ottenstein, Laura; Douglas, Donya; Hoang, Triem

2010-01-01

Under NASA s New Millennium Program Space Technology 8 (ST 8) Project, Goddard Space Fight Center has conducted a Thermal Loop experiment to advance the maturity of the Thermal Loop technology from proof of concept to prototype demonstration in a relevant environment , i.e. from a technology readiness level (TRL) of 3 to a level of 6. The thermal Loop is an advanced thermal control system consisting of a miniature loop heat pipe (MLHP) with multiple evaporators and multiple condensers designed for future small system applications requiring low mass, low power, and compactness. The MLHP retains all features of state-of-the-art loop heat pipes (LHPs) and offers additional advantages to enhance the functionality, performance, versatility, and reliability of the system. An MLHP breadboard was built and tested in the laboratory and thermal vacuum environments for the TRL 4 and TRL 5 validations, respectively, and an MLHP proto-flight unit was built and tested in a thermal vacuum chamber for the TRL 6 validation. In addition, an analytical model was developed to simulate the steady state and transient behaviors of the MLHP during various validation tests. The MLHP demonstrated excellent performance during experimental tests and the analytical model predictions agreed very well with experimental data. All success criteria at various TRLs were met. Hence, the Thermal Loop technology has reached a TRL of 6. This paper presents the validation results, both experimental and analytical, of such a technology development effort.

RF Performance of Membrane Aperture Shells

NASA Technical Reports Server (NTRS)

Flint, Eirc M.; Lindler, Jason E.; Thomas, David L.; Romanofsky, Robert

2007-01-01

This paper provides an overview of recent results establishing the suitability of Membrane Aperture Shell Technology (MAST) for Radio Frequency (RF) applications. These single surface shells are capable of maintaining their figure with no preload or pressurization and minimal boundary support, yet can be compactly roll stowed and passively self deploy. As such, they are a promising technology for enabling a future generation of RF apertures. In this paper, we review recent experimental and numerical results quantifying suitable RF performance. It is shown that candidate materials possess metallic coatings with sufficiently low surface roughness and that these materials can be efficiently fabricated into RF relevant doubly curved shapes. A numerical justification for using a reflectivity metric, as opposed to the more standard RF designer metric of skin depth, is presented and the resulting ability to use relatively thin coating thickness is experimentally validated with material sample tests. The validity of these independent film sample measurements are then confirmed through experimental results measuring RF performance for reasonable sized doubly curved apertures. Currently available best results are 22 dBi gain at 3 GHz (S-Band) for a 0.5m aperture tested in prime focus mode, 28dBi gain for the same antenna in the C-Band (4 to 6 GHz), and 36.8dBi for a smaller 0.25m antenna tested at 32 GHz in the Ka-Band. RF range test results for a segmented aperture (one possible scaling approach) are shown as well. Measured antenna system actual efficiencies (relative to the unachievable) ideal for these on axis tests are generally quite good, typically ranging from 50 to 90%.

The Effect of Asymmetric Mechanical and Thermal Loading on Membrane Wrinkling

NASA Technical Reports Server (NTRS)

Blandino, Joseph R.; Johnston, John D.; Miles, Jonathan J.; Dharamsi, Urmil K.; Brodeur, Stephen J. (Technical Monitor)

2002-01-01

Large, tensioned membranes are being considered for future gossamer spacecraft systems. Examples include sunshields, solar sails, and membrane optics. In many. cases a relatively flat membrane with minimal wrinkling is desired. Developing methods to predict and measure membrane wrinkling is important to the future development of gossamer spacecraft. Numerical and experimental data are presented for a 0.5 m square, tensioned membrane. The membrane is subjected to symmetric and asymmetric mechanical loading. Data are also presented for a symmetrically loaded membrane subjected to spot heating in the center. The numerical model shows good agreement with the experiment for wrinkle angle data. There is. also reasonable agreement for the wrinkled area for both isothermal and elevated temperature tests.

Working memory training and semantic structuring improves remembering future events, not past events.

PubMed

Richter, Kim Merle; Mödden, Claudia; Eling, Paul; Hildebrandt, Helmut

2015-01-01

Objectives. Memory training in combination with practice in semantic structuring and word fluency has been shown to improve memory performance. This study investigated the efficacy of a working memory training combined with exercises in semantic structuring and word fluency and examined whether training effects generalize to other cognitive tasks. Methods. In this double-blind randomized control study, 36 patients with memory impairments following brain damage were allocated to either the experimental or the active control condition, with both groups receiving 9 hours of therapy. The experimental group received a computer-based working memory training and exercises in word fluency and semantic structuring. The control group received the standard memory therapy provided in the rehabilitation center. Patients were tested on a neuropsychological test battery before and after therapy, resulting in composite scores for working memory; immediate, delayed, and prospective memory; word fluency; and attention. Results. The experimental group improved significantly in working memory and word fluency. The training effects also generalized to prospective memory tasks. No specific effect on episodic memory could be demonstrated. Conclusion. Combined treatment of working memory training with exercises in semantic structuring is an effective method for cognitive rehabilitation of organic memory impairment. © The Author(s) 2014.

Parity and Time-Reversal Violation in Atomic Systems

NASA Astrophysics Data System (ADS)

Roberts, B. M.; Dzuba, V. A.; Flambaum, V. V.

2015-10-01

Studying the violation of parity and time-reversal invariance in atomic systems has proven to be a very effective means of testing the electroweak theory at low energy and searching for physics beyond it. Recent developments in both atomic theory and experimental methods have led to the ability to make extremely precise theoretical calculations and experimental measurements of these effects. Such studies are complementary to direct high-energy searches, and can be performed for only a fraction of the cost. We review the recent progress in the field of parity and time-reversal violation in atoms, molecules, and nuclei, and examine the implications for physics beyond the Standard Model, with an emphasis on possible areas for development in the near future.

Theoretical and experimental research in aeroelastic stability of an advanced bearingless rotor for future helicopters

NASA Technical Reports Server (NTRS)

Wang, James M.

1991-01-01

The aeroelastic stability of a shaft-fixed bearingless rotor is analyzed in wind-tunnel tests for a wide range of operating conditions in order to determine whether such a system could be made aeroelastically stable without incorporating auxiliary dampers. The model rotor and blade properties are determined and used as an input to a bearingless-rotor analysis. Theoretical predictions are compared with experimental results in hover and forward flights. The analysis predicts the lag mode damping satisfactorily for collective pitch between 5 deg and 10 deg; however, the quasi-steady linear aerodynamic modeling overpredicts the damping values for higher collective pitch settings. It is noted that soft blade pitch links improve aeroelastic stability in hover and at low advance ratio.

Experimental and theoretical analysis of integrated circuit (IC) chips on flexible substrates subjected to bending

NASA Astrophysics Data System (ADS)

Chen, Ying; Yuan, Jianghong; Zhang, Yingchao; Huang, Yonggang; Feng, Xue

2017-10-01

The interfacial failure of integrated circuit (IC) chips integrated on flexible substrates under bending deformation has been studied theoretically and experimentally. A compressive buckling test is used to impose the bending deformation onto the interface between the IC chip and the flexible substrate quantitatively, after which the failed interface is investigated using scanning electron microscopy. A theoretical model is established based on the beam theory and a bi-layer interface model, from which an analytical expression of the critical curvature in relation to the interfacial failure is obtained. The relationships between the critical curvature, the material, and the geometric parameters of the device are discussed in detail, providing guidance for future optimization flexible circuits based on IC chips.

Robotic follower experimentation results: ready for FCS increment I

NASA Astrophysics Data System (ADS)

Jaczkowski, Jeffrey J.

2003-09-01

Robotics is a fundamental enabling technology required to meet the U.S. Army's vision to be a strategically responsive force capable of domination across the entire spectrum of conflict. The U. S. Army Research, Development and Engineering Command (RDECOM) Tank Automotive Research, Development & Engineering Center (TARDEC), in partnership with the U.S. Army Research Laboratory, is developing a leader-follower capability for Future Combat Systems. The Robotic Follower Advanced Technology Demonstration (ATD) utilizes a manned leader to provide a highlevel proofing of the follower's path, which operates with minimal user intervention. This paper will give a programmatic overview and discuss both the technical approach and operational experimentation results obtained during testing conducted at Ft. Bliss, New Mexico in February-March 2003.

Fit to Forgive: Effect of Mode of Exercise on Capacity to Override Grudges and Forgiveness

PubMed Central

Struthers, C. Ward; van Monsjou, Elizabeth; Ayoub, Mariam; Guilfoyle, Joshua R.

2017-01-01

Forgiveness is important for repairing relationships that have been damaged by transgressions. In this research we explored the notion that the mode of physical exercise that victims of transgressions engage in and their capacity to override grudges are important in the process of forgiveness. Two exploratory studies that varied in samples (community non-student adults, undergraduate students) and research methods (non-experimental, experimental) were used to test these predictions. Findings showed that, compared to anaerobic or no exercise, aerobic and flexibility exercise facilitated self-control over grudges and forgiveness (Studies 1 and 2), and self-control over grudges explained the relation between exercise and forgiveness (Study 2). Possible mechanisms for future research are discussed. PMID:28533758

Features and characterization needs of rubber composite structures

NASA Technical Reports Server (NTRS)

Tabaddor, Farhad

1989-01-01

Some of the major unique features of rubber composite structures are outlined. The features covered are those related to the material properties, but the analytical features are also briefly discussed. It is essential to recognize these features at the planning stage of any long-range analytical, experimental, or application program. The development of a general and comprehensive program which fully accounts for all the important characteristics of tires, under all the relevant modes of operation, may present a prohibitively expensive and impractical task at the near future. There is therefore a need to develop application methodologies which can utilize the less general models, beyond their theoretical limitations and yet with reasonable reliability, by proper mix of analytical, experimental, and testing activities.

Usage of machine learning for the separation of electroweak and strong Zγ production at the LHC experiments

NASA Astrophysics Data System (ADS)

Petukhov, A. M.; Soldatov, E. Yu

2017-12-01

Separation of electroweak component from strong component of associated Zγ production on hadron colliders is a very challenging task due to identical final states of such processes. The only difference is the origin of two leading jets in these two processes. Rectangular cuts on jet kinematic variables from ATLAS/CMS 8 TeV Zγ experimental analyses were improved using machine learning techniques. New selection variables were also tested. The expected significance of separation for LHC experiments conditions at the second datataking period (Run2) and 120 fb-1 amount of data reaches more than 5σ. Future experimental observation of electroweak Zγ production can also lead to the observation physics beyond Standard Model.

Jefferson Lab Science: Present and Future

DOE PAGES

McKeown, Robert D.

2015-02-12

The Continuous Electron Beam Accelerator Facility (CEBAF) and associated experimental equipment at Jefferson Lab comprise a unique facility for experimental nuclear physics. Furthermore, this facility is presently being upgraded, which will enable a new experimental program with substantial discovery potential to address important topics in nuclear, hadronic, and electroweak physics. Further in the future, it is envisioned that the Laboratory will evolve into an electron-ion colliding beam facility.

Experimental characterization of thermally-activated artificial muscles based on coiled nylon fishing lines

NASA Astrophysics Data System (ADS)

Cherubini, Antonello; Moretti, Giacomo; Vertechy, Rocco; Fontana, Marco

2015-06-01

The discovery of an innovative class of thermally activated actuators based on twisted polymeric fibres has opened new horizons toward the development of effective devices that can be easily manufactured using inexpensive materials such as fishing lines or sewing threads. These new devices show large deformations when heated together with promising performance in terms of energy and power densities. With the aim of providing information and data useful for the future engineering applications, we present the results of a thermo-mechanical characterization conducted on a specific type of twisted polymeric fibre (i.e. nylon-made coiled actuators) that is considered particularly promising. A custom experimental test-bench and procedure have been developed and employed to run isothermal and isometric tensile tests on a set of specimens that are fabricated with a simple and repeatable process. The results of the experiments highlight some important issues related to the response of these actuators such as hysteresis, repeatability, predictability and stored elastic energy.

(Boiling water reactor (BWR) CORA experiments)

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

Ott, L.J.

To participate in the 1990 CORA Workshop at Kernforschungszentrum Karlsruhe (KfK) GmbH, Karlsruhe, FRG, on October 1--4, and to participate in detailed discussions on October 5 with the KfK CORA Boiling Water Reactor (BWR) experiments. The traveler attended the 1990 CORA Workshop at KfK, FRG. Participation included the presentation of a paper on work performed by the Boiling Water Reactor Core Melt Progression Phenomena Program at Oak Ridge National Laboratory (ORNL) on posttest analyses of CORA BWR experiments. The Statement of Work (November 1989) for the BWR Core Melt Progression Phenomena Program provides for pretest and posttest analyses of themore » BWR CORA experiments performed at KfK. Additionally, it is intended that ORNL personnel participate in the planning process for future CORA BWR experiments. For these purposes, meetings were held with KfK staff to discuss such topics as (1) experimental test schedule, (2) BWR test conduct, (3) perceived BWR experimental needs, and (4) KfK operational staff needs with respect to ORNL support. 19 refs.« less

Effects of Distortion on Mass Flow Plug Calibration

NASA Technical Reports Server (NTRS)

Sasson, Jonathan; Davis, David O.; Barnhart, Paul J.

2015-01-01

A numerical, and experimental investigation to study the effects of flow distortion on a Mass Flow Plug (MFP) used to control and measure mass-flow during an inlet test has been conducted. The MFP was first calibrated using the WIND-US flow solver for uniform (undistorted) inflow conditions. These results are shown to compare favorably with an experimental calibration under similar conditions. The effects of distortion were investigated by imposing distorted flow conditions taken from an actual inlet test to the inflow plane of the numerical simulation. The computational fluid dynamic (CFD) based distortion study only showed the general trend in mass flow rate. The study used only total pressure as the upstream boundary condition, which was not enough to define the flow. A better simulation requires knowledge of the turbulence structure and a specific distortion pattern over a range of plug positions. It is recommended that future distortion studies utilize a rake with at least the same amount of pitot tubes as the AIP rake.

Enabling CSPA Operations Through Pilot Involvement in Longitudinal Approach Spacing

NASA Technical Reports Server (NTRS)

Battiste, Vernol (Technical Monitor); Pritchett, Amy

2003-01-01

Several major airports around the United States have, or plan to have, closely-spaced parallel runways. This project complemented current and previous research by examining the pilots ability to control their position longitudinally within their approach stream.This project s results considered spacing for separation from potential positions of wake vortices from the parallel approach. This preventive function could enable CSPA operations to very closely spaced runways. This work also considered how pilot involvement in longitudinal spacing could allow for more efficient traffic flow, by allowing pilots to keep their aircraft within tighter arrival slots then air traffic control (ATC) might be able to establish, and by maintaining space within the arrival stream for corresponding departure slots. To this end, this project conducted several research studies providing an analytic and computational basis for calculating appropriate aircraft spacings, experimental results from a piloted flight simulator test, and an experimental testbed for future simulator tests. The following sections summarize the results of these three efforts.

Experimental clean combustor program, phase 2

NASA Technical Reports Server (NTRS)

Roberts, R.; Peduzzi, A.; Vitti, G. E.

1976-01-01

The alternate fuels investigation objective was to experimentally determine the impacts, if any, on exhaust emissions, performance, and durability characteristics of the hybrid and vorbix low pollution combustor concepts when operated on test fuels which simulate composition and property changes which might result from future broadened aviation turbine fuel specifications or use of synthetically derived crude feedstocks. Results of the program indicate a significant increase in CO and small NOX increase in emissions at idle for both combustor concepts, and an increase in THC for the vorbix concept. Minimal impact was observed on gaseous emissions at high power. The vorbix concept exhibited significant increase in exhaust smoke with increasing fuel aromatic content. Altitude stability was not affected for the vorbix combustor, but was substantially reduced for the hybrid concept. Severe carbon deposition was observed in both combustors following limited endurance testing with No. 2 home heat fuel. Liner temperature levels were insensitive to variations in aromatic content over the range of conditions investigated.

Tensile Properties of Polymeric Matrix Composites Subjected to Cryogenic Environments

NASA Technical Reports Server (NTRS)

Whitley, Karen S.; Gates, Thomas S.

2004-01-01

Polymer matrix composites (PMC s) have seen limited use as structural materials in cryogenic environments. One reason for the limited use of PMC s in cryogenic structures is a design philosophy that typically requires a large, validated database of material properties in order to ensure a reliable and defect free structure. It is the intent of this paper to provide an initial set of mechanical properties developed from experimental data of an advanced PMC (IM7/PETI-5) exposed to cryogenic temperatures and mechanical loading. The application of this data is to assist in the materials down-select and design of cryogenic fuel tanks for future reusable space vehicles. The details of the material system, test program, and experimental methods will be outlined. Tension modulus and strength were measured at room temperature, -196 C, and -269 C on five different laminates. These properties were also tested after aging at -186 C with and without loading applied. Microcracking was observed in one laminate.

Experimental metaphysics2 : The double standard in the quantum-information approach to the foundations of quantum theory

NASA Astrophysics Data System (ADS)

Hagar, Amit

Among the alternatives of non-relativistic quantum mechanics (NRQM) there are those that give different predictions than quantum mechanics in yet-untested circumstances, while remaining compatible with current empirical findings. In order to test these predictions, one must isolate one's system from environmental induced decoherence, which, on the standard view of NRQM, is the dynamical mechanism that is responsible for the 'apparent' collapse in open quantum systems. But while recent advances in condensed-matter physics may lead in the near future to experimental setups that will allow one to test the two hypotheses, namely genuine collapse vs. decoherence, hence make progress toward a solution to the quantum measurement problem, those philosophers and physicists who are advocating an information-theoretic approach to the foundations of quantum mechanics are still unwilling to acknowledge the empirical character of the issue at stake. Here I argue that in doing so they are displaying an unwarranted double standard.

Lorentz violation and gravity

NASA Astrophysics Data System (ADS)

Bailey, Quentin G.

2007-08-01

This work explores the theoretical and experimental aspects of Lorentz violation in gravity. A set of modified Einstein field equations is derived from the general Lorentz-violating Standard-Model Extension (SME). Some general theoretical implications of these results are discussed. The experimental consequences for weak-field gravitating systems are explored in the Earth- laboratory setting, the solar system, and beyond. The role of spontaneous Lorentz-symmetry breaking is discussed in the context of the pure-gravity sector of the SME. To establish the low-energy effective Einstein field equations, it is necessary to take into account the dynamics of 20 coefficients for Lorentz violation. As an example, the results are compared with bumblebee models, which are general theories of vector fields with spontaneous Lorentz violation. The field equations are evaluated in the post- newtonian limit using a perfect fluid description of matter. The post-newtonian metric of the SME is derived and compared with some standard test models of gravity. The possible signals for Lorentz violation due to gravity-sector coefficients are studied. Several new effects are identified that have experimental implications for current and future tests. Among the unconventional effects are a new type of spin precession for a gyroscope in orbit and a modification to the local gravitational acceleration on the Earth's surface. These and other tests are expected to yield interesting sensitivities to dimensionless gravity- sector coefficients.

Quantifying Astronaut Tasks: Robotic Technology and Future Space Suit Design

NASA Technical Reports Server (NTRS)

Newman, Dava

2003-01-01

The primary aim of this research effort was to advance the current understanding of astronauts' capabilities and limitations in space-suited EVA by developing models of the constitutive and compatibility relations of a space suit, based on experimental data gained from human test subjects as well as a 12 degree-of-freedom human-sized robot, and utilizing these fundamental relations to estimate a human factors performance metric for space suited EVA work. The three specific objectives are to: 1) Compile a detailed database of torques required to bend the joints of a space suit, using realistic, multi- joint human motions. 2) Develop a mathematical model of the constitutive relations between space suit joint torques and joint angular positions, based on experimental data and compare other investigators' physics-based models to experimental data. 3) Estimate the work envelope of a space suited astronaut, using the constitutive and compatibility relations of the space suit. The body of work that makes up this report includes experimentation, empirical and physics-based modeling, and model applications. A detailed space suit joint torque-angle database was compiled with a novel experimental approach that used space-suited human test subjects to generate realistic, multi-joint motions and an instrumented robot to measure the torques required to accomplish these motions in a space suit. Based on the experimental data, a mathematical model is developed to predict joint torque from the joint angle history. Two physics-based models of pressurized fabric cylinder bending are compared to experimental data, yielding design insights. The mathematical model is applied to EVA operations in an inverse kinematic analysis coupled to the space suit model to calculate the volume in which space-suited astronauts can work with their hands, demonstrating that operational human factors metrics can be predicted from fundamental space suit information.

The Confrontation between General Relativity and Experiment.

PubMed

Will, Clifford M

2001-01-01

The status of experimental tests of general relativity and of theoretical frameworks for analysing them are reviewed. Einstein's equivalence principle (EEP) is well supported by experiments such as the Eötvös experiment, tests of special relativity, and the gravitational redshift experiment. Future tests of EEP and of the inverse square law will search for new interactions arising from unification or quantum gravity. Tests of general relativity at the post-Newtonian level have reached high precision, including the light defl ection the Shapiro time delay, the perihelion advance of Mercury, and the Nordtvedt effect in lunar motion. Gravitational wave damping has been detected in an amount that agrees with general relativity to half a percent using the Hulse-Taylor binary pulsar, and new binary pulsar systems may yield further improvements. When direct observation of gravitational radiation from astrophysical sources begins, new tests of general relativity will be possible.

QCSEE UTW engine powered-lift acoustic performance

NASA Technical Reports Server (NTRS)

Loeffler, I. J.; Samanich, N. E.; Bloomer, H. E.

1980-01-01

Powered-lift acoustic test of the Quiet Clean Short Haul Experimental Engine (QCSEE) under the wing (UTW) engine are reported. Propulsion systems for two powered-lift concepts were designed, fabricated, and tested. In addition to low noise features, the designs included composite structures, gear-driven fans, digital control, and a variable pitch fan (UTW). The UTW engine was tested in a static ground test facility with wing and flap segments to simulate installation on a short haul transport aircraft of the future. Powered-lift acoustic performance of the UTW engine is compared with that of the previously tested and reported QCSEE over-the-wing (OTW) engine. Both engines were slightly above the noise goal but were significantly below current FAA and modern wide-body jet transport levels. The UTW system in the powered-lift mode was penalized by reflected engine noise from the wing and flap system, while the OTW system was benefitted by a wing noise shielding effect.

Descriptive Summaries of the Research Development Test & Evaluation. Army Appropriation FY 1984. Supporting Data FY 1984 Budget Estimate Submitted to Congress--February 1983. Volume I.

DTIC Science & Technology

1983-02-01

s.,ccesstully modeled to enhance future computer design simulations; (2) a new methodology for conduc*n dynamic analysis of vehicle mechanics was...to prelminary design methodology for tilt rotors, advancing blade concepts configuration helicopters, and compound helicopters in conjunction with...feasibility of low-level personnel parachutes has been demon- strated. A study was begun to design a free-fall water contalner. An experimental program to

A Joint Army/Air Force Investigation of Reflection Coefficients at C and Ku Bands for Vertical, Horizontal and Circular System Polarizations

DTIC Science & Technology

1976-07-01

experimental operations, one assesses the realibility of his data in terms of its repeatability. In fact, during the present experiments an effort was... Data Handler Documentation, lIT Research Institute, September 1974 9. Brindley, A.E., et al, Analysis , Test and Evaluation Support to the USAF Advanced...surface above the building foundation level. A.6.3 SURVEYING TECHNIQUE. ACCUKACY, FUTURE USLU An accuracy analysis was not run on the survey data , but

Technology requirements to be addressed by the NASA Lewis Research Center Cryogenic Fluid Management Facility program

NASA Technical Reports Server (NTRS)

Aydelott, J. C.; Rudland, R. S.

1985-01-01

The NASA Lewis Research Center is responsible for the planning and execution of a scientific program which will provide advance in space cryogenic fluid management technology. A number of future space missions were identified that require or could benefit from this technology. These fluid management technology needs were prioritized and a shuttle attached reuseable test bed, the cryogenic fluid management facility (CFMF), is being designed to provide the experimental data necessary for the technology development effort.

Space Station Live: Everythings Coming up Veggie

NASA Image and Video Library

2016-04-13

NASA Commentator Lori Meggs at the Marshall Space Flight Center talks about the latest work of the Veggie experiment on board the International Space Station with Gioia Massa, the Veggie project scientist. The experimental compact greenhouse has been used successfully to grow two crops of lettuce and a crop of zinnias, demonstrating an ability to grow crops in space that could be very useful for future exploration missions out into the solar systems. More tests are on the agenda as specialists improve the capabilities of the system.

Propeller flow visualization techniques

NASA Technical Reports Server (NTRS)

Stefko, G. L.; Paulovich, F. J.; Greissing, J. P.; Walker, E. D.

1982-01-01

Propeller flow visualization techniques were tested. The actual operating blade shape as it determines the actual propeller performance and noise was established. The ability to photographically determine the advanced propeller blade tip deflections, local flow field conditions, and gain insight into aeroelastic instability is demonstrated. The analytical prediction methods which are being developed can be compared with experimental data. These comparisons contribute to the verification of these improved methods and give improved capability for designing future advanced propellers with enhanced performance and noise characteristics.

Subscale Flight Testing for Aircraft Loss of Control: Accomplishments and Future Directions

NASA Technical Reports Server (NTRS)

Cox, David E.; Cunningham, Kevin; Jordan, Thomas L.

2012-01-01

Subscale flight-testing provides a means to validate both dynamic models and mitigation technologies in the high-risk flight conditions associated with aircraft loss of control. The Airborne Subscale Transport Aircraft Research (AirSTAR) facility was designed to be a flexible and efficient research facility to address this type of flight-testing. Over the last several years (2009-2011) it has been used to perform 58 research flights with an unmanned, remotely-piloted, dynamically-scaled airplane. This paper will present an overview of the facility and its architecture and summarize the experimental data collected. All flights to date have been conducted within visual range of a safety observer. Current plans for the facility include expanding the test volume to altitudes and distances well beyond visual range. The architecture and instrumentation changes associated with this upgrade will also be presented.

IceVal DatAssistant: An Interactive, Automated Icing Data Management System

NASA Technical Reports Server (NTRS)

Levinson, Laurie H.; Wright, William B.

2008-01-01

As with any scientific endeavor, the foundation of icing research at the NASA Glenn Research Center (GRC) is the data acquired during experimental testing. In the case of the GRC Icing Branch, an important part of this data consists of ice tracings taken following tests carried out in the GRC Icing Research Tunnel (IRT), as well as the associated operational and environmental conditions documented during these tests. Over the years, the large number of experimental runs completed has served to emphasize the need for a consistent strategy for managing this data. To address the situation, the Icing Branch has recently elected to implement the IceVal DatAssistant automated data management system. With the release of this system, all publicly available IRT-generated experimental ice shapes with complete and verifiable conditions have now been compiled into one electronically-searchable database. Simulation software results for the equivalent conditions, generated using the latest version of the LEWICE ice shape prediction code, are likewise included and are linked to the corresponding experimental runs. In addition to this comprehensive database, the IceVal system also includes a graphically-oriented database access utility, which provides reliable and easy access to all data contained in the database. In this paper, the issues surrounding historical icing data management practices are discussed, as well as the anticipated benefits to be achieved as a result of migrating to the new system. A detailed description of the software system features and database content is also provided; and, finally, known issues and plans for future work are presented.

IceVal DatAssistant: An Interactive, Automated Icing Data Management System

NASA Technical Reports Server (NTRS)

Levinson, Laurie H.; Wright, William B.

2008-01-01

As with any scientific endeavor, the foundation of icing research at the NASA Glenn Research Center (GRC) is the data acquired during experimental testing. In the case of the GRC Icing Branch, an important part of this data consists of ice tracings taken following tests carried out in the GRC Icing Research Tunnel (IRT), as well as the associated operational and environmental conditions during those tests. Over the years, the large number of experimental runs completed has served to emphasize the need for a consistent strategy to manage the resulting data. To address this situation, the Icing Branch has recently elected to implement the IceVal DatAssistant automated data management system. With the release of this system, all publicly available IRT-generated experimental ice shapes with complete and verifiable conditions have now been compiled into one electronically-searchable database; and simulation software results for the equivalent conditions, generated using the latest version of the LEWICE ice shape prediction code, are likewise included and linked to the corresponding experimental runs. In addition to this comprehensive database, the IceVal system also includes a graphically-oriented database access utility, which provides reliable and easy access to all data contained in the database. In this paper, the issues surrounding historical icing data management practices are discussed, as well as the anticipated benefits to be achieved as a result of migrating to the new system. A detailed description of the software system features and database content is also provided; and, finally, known issues and plans for future work are presented.

An experimental test of the effect of acute anxious arousal and anxiety sensitivity on negative reinforcement smoking.

PubMed

Farris, Samantha G; Zvolensky, Michael J

2016-07-01

Although anxiety sensitivity has been reliably associated with smoking-anxiety comorbidity, there has not been a test of whether this construct moderates the effect of acute anxious arousal on actual smoking behavior. The present study utilized an experimental design to test the moderating role of anxiety sensitivity on laboratory-induced anxious arousal in terms of smoking urges and topography (puff style). Participants were adult daily smokers (n=90; Mage=43.6 SD =9.7); average 15.8 cigarettes per day). A between-subjects design was used; participants were randomly assigned to complete a biological challenge procedure consisting of either a single vital capacity inhalation of 35% carbon dioxide (CO2)-enriched air mixture or compressed room air. Smoking urges and smoking topography (puff behavior) were assessed before and after the challenge. Results revealed a significant interaction between anxiety sensitivity and experimental condition (b=-9.96, p=0.014), such that high anxiety sensitive smokers exposed to 35% CO2-enriched air reported significantly lower levels of smoking urges, relative to low anxiety sensitive smokers; the conditional effect of anxiety sensitivity was not observed for the room air condition. There were no significant interaction effects of experimental manipulation by anxiety sensitivity for any of the smoking topography outcomes. The present results suggest for smokers with higher levels of anxiety sensitivity, the acute experience of anxious arousal is related to decreased subjective smoking urges. These data invite future research to explore the reasons for dampened smoking urges, including cardiorespiratory symptom severity. © The Author(s) 2016.

Computational fluid dynamic modeling of a medium-sized surface mine blasthole drill shroud

PubMed Central

Zheng, Y.; Reed, W.R.; Zhou, L.; Rider, J.P.

2016-01-01

The Pittsburgh Mining Research Division of the U.S. National Institute for Occupational Safety and Health (NIOSH) recently developed a series of models using computational fluid dynamics (CFD) to study airflows and respirable dust distribution associated with a medium-sized surface blasthole drill shroud with a dry dust collector system. Previously run experiments conducted in NIOSH’s full-scale drill shroud laboratory were used to validate the models. The setup values in the CFD models were calculated from experimental data obtained from the drill shroud laboratory and measurements of test material particle size. Subsequent simulation results were compared with the experimental data for several test scenarios, including 0.14 m3/s (300 cfm) and 0.24 m3/s (500 cfm) bailing airflow with 2:1, 3:1 and 4:1 dust collector-to-bailing airflow ratios. For the 2:1 and 3:1 ratios, the calculated dust concentrations from the CFD models were within the 95 percent confidence intervals of the experimental data. This paper describes the methodology used to develop the CFD models, to calculate the model input and to validate the models based on the experimental data. Problem regions were identified and revealed by the study. The simulation results could be used for future development of dust control methods for a surface mine blasthole drill shroud. PMID:27932851

TESTING AND PERFORMANCE ANALYSIS OF NASA 5 CM BY 5 CM BI-SUPPORTED SOLID OXIDE ELECTROLYSIS CELLS OPERATED IN BOTH FUEL CELL AND STEAM ELECTROLYSIS MODES

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

R. C. O'Brien; J. E. O'Brien; C. M. Stoots

A series of 5 cm by 5 cm bi-supported Solid Oxide Electrolysis Cells (SOEC) were produced by NASA for the Idaho National Laboratory (INL) and tested under the INL High Temperature Steam Electrolysis program. The results from the experimental demonstration of cell operation for both hydrogen production and operation as fuel cells is presented. An overview of the cell technology, test apparatus and performance analysis is also provided. The INL High Temperature Steam Electrolysis laboratory has developed significant test infrastructure in support of single cell and stack performance analyses. An overview of the single cell test apparatus is presented. Themore » test data presented in this paper is representative of a first batch of NASA's prototypic 5 cm by 5 cm SOEC single cells. Clearly a significant relationship between the operational current density and cell degradation rate is evident. While the performance of these cells was lower than anticipated, in-house testing at NASA Glenn has yielded significantly higher performance and lower degradation rates with subsequent production batches of cells. Current post-test microstructure analyses of the cells tested at INL will be published in a future paper. Modification to cell compositions and cell reduction techniques will be altered in the next series of cells to be delivered to INL with the aim to decrease the cell degradation rate while allowing for higher operational current densities to be sustained. Results from the testing of new batches of single cells will be presented in a future paper.« less

Hiding the tobacco power wall reduces cigarette smoking risk in adolescents: using an experimental convenience store to assess tobacco regulatory options at retail point-of-sale.

PubMed

Shadel, William G; Martino, Steven C; Setodji, Claude M; Scharf, Deborah M; Kusuke, Daniela; Sicker, Angela; Gong, Min

2015-11-23

This experiment tested whether changing the location or visibility of the tobacco power wall in a life sized replica of a convenience store had any effect on adolescents' susceptibility to future cigarette smoking. The study was conducted in the RAND StoreLab (RSL), a life sized replica of a convenience store that was developed to experimentally evaluate how changing aspects of tobacco advertising displays in retail point-of-sale environments influences tobacco use risk and behaviour. A randomised, between-subjects experimental design with three conditions that varied the location or visibility of the tobacco power wall within the RSL was used. The conditions were: cashier (the tobacco power wall was located in its typical position behind the cash register counter); sidewall (the tobacco power wall was located on a sidewall away from the cash register); or hidden (the tobacco power wall was located behind the cashier but was hidden behind an opaque wall). The sample included 241 adolescents. Hiding the tobacco power wall significantly reduced adolescents' susceptibility to future cigarette smoking compared to leaving it exposed (ie, the cashier condition; p=0.02). Locating the tobacco power wall on a sidewall away from the cashier had no effect on future cigarette smoking susceptibility compared to the cashier condition (p=0.80). Hiding the tobacco power wall at retail point-of-sale locations is a strong regulatory option for reducing the impact of the retail environment on cigarette smoking risk in adolescents. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

The NASA Lewis Research Center Internal Fluid Mechanics Facility

NASA Technical Reports Server (NTRS)

Porro, A. R.; Hingst, W. R.; Wasserbauer, C. A.; Andrews, T. B.

1991-01-01

An experimental facility specifically designed to investigate internal fluid duct flows is described. It is built in a modular fashion so that a variety of internal flow test hardware can be installed in the facility with minimal facility reconfiguration. The facility and test hardware interfaces are discussed along with design constraints of future test hardware. The plenum flow conditioning approach is also detailed. Available instrumentation and data acquisition capabilities are discussed. The incoming flow quality was documented over the current facility operating range. The incoming flow produces well behaved turbulent boundary layers with a uniform core. For the calibration duct used, the boundary layers approached 10 percent of the duct radius. Freestream turbulence levels at the various operating conditions varied from 0.64 to 0.69 percent of the average freestream velocity.

Analytical and Experimental Verification of a Flight Article for a Mach-8 Boundary-Layer Experiment

NASA Technical Reports Server (NTRS)

Richards, W. Lance; Monaghan, Richard C.

1996-01-01

Preparations for a boundary-layer transition experiment to be conducted on a future flight mission of the air-launched Pegasus(TM) rocket are underway. The experiment requires a flight-test article called a glove to be attached to the wing of the Mach-8 first-stage booster. A three-dimensional, nonlinear finite-element analysis has been performed and significant small-scale laboratory testing has been accomplished to ensure the glove design integrity and quality of the experiment. Reliance on both the analysis and experiment activities has been instrumental in the success of the flight-article design. Results obtained from the structural analysis and laboratory testing show that all glove components are well within the allowable thermal stress and deformation requirements to satisfy the experiment objectives.

Rapid Model Fabrication and Testing for Aerospace Vehicles

NASA Technical Reports Server (NTRS)

Buck, Gregory M.

2000-01-01

Advanced methods for rapid fabrication and instrumentation of hypersonic wind tunnel models are being developed and evaluated at NASA Langley Research Center. Rapid aeroheating model fabrication and measurement techniques using investment casting of ceramic test models and thermographic phosphors are reviewed. More accurate model casting techniques for fabrication of benchmark metal and ceramic test models are being developed using a combination of rapid prototype patterns and investment casting. White light optical scanning is used for coordinate measurements to evaluate the fabrication process and verify model accuracy to +/- 0.002 inches. Higher-temperature (<210C) luminescent coatings are also being developed for simultaneous pressure and temperature mapping, providing global pressure as well as global aeroheating measurements. Together these techniques will provide a more rapid and complete experimental aerodynamic and aerothermodynamic database for future aerospace vehicles.

A test to verify the biocompatibility of a method for plant culture in a microgravity environment

NASA Technical Reports Server (NTRS)

Brown, A. H.; Chapman, D. K.

1984-01-01

We report a pioneering attempt to use the NASA Shuttle Orbiter Middeck locker facility to acquire data on plant growth in near weightlessness. The information was needed to confirm the suitability of a plant culture system to be used in an experiment scheduled for the first Spacelab mission. The test was designed to measure germination and early seedling growth in a series of soil mixtures covering a range of water contents. Empirical determination of growth dependence on moisture content was required because both in theory and from Soviet flight experience it seemed possible that the dependence function in near weightlessness could be critically different from what we had measured on Earth. Such a difference could invalidate the future test in Spacelab 1 of gravity dependence of the differential growth process, circumnutation. After two failed attempts sufficient measurements were obtained from the third Shuttle Orbiter flight test to confirm the biocompatibility of the plant culture system--viz. soil moisture content variations had the same effect in near weightlessness as at 1 g. A number of supplemental observations about middeck locker conditions in Shuttle flight are presented. These may prove helpful to would-be experimenters who will plan to take advantage of future Shuttle flight opportunities for biological research.

Development of NASA's Space Communications and Navigation Test Bed Aboard ISS to Investigate SDR, On-Board Networking and Navigation Technologies

NASA Technical Reports Server (NTRS)

Reinhart, Richard C.; Kacpura, Thomas J.; Johnson, Sandra K.; Lux, James P.

2010-01-01

NASA is developing an experimental flight payload (referred to as the Space Communication and Navigation (SCAN) Test Bed) to investigate software defined radio (SDR), networking, and navigation technologies, operationally in the space environment. The payload consists of three software defined radios each compliant to NASA s Space Telecommunications Radio System Architecture, a common software interface description standard for software defined radios. The software defined radios are new technology developments underway by NASA and industry partners. Planned for launch in early 2012, the payload will be externally mounted to the International Space Station truss and conduct experiments representative of future mission capability.

Experimental Tests of the Algebraic Cluster Model

NASA Astrophysics Data System (ADS)

Gai, Moshe

2018-02-01

The Algebraic Cluster Model (ACM) of Bijker and Iachello that was proposed already in 2000 has been recently applied to 12C and 16O with much success. We review the current status in 12C with the outstanding observation of the ground state rotational band composed of the spin-parity states of: 0+, 2+, 3-, 4± and 5-. The observation of the 4± parity doublet is a characteristic of (tri-atomic) molecular configuration where the three alpha- particles are arranged in an equilateral triangular configuration of a symmetric spinning top. We discuss future measurement with electron scattering, 12C(e,e’) to test the predicted B(Eλ) of the ACM.

Construction of the prototype of an optical system for measurement of small wavefront distortion of laser radiation in optical elements: proposal for the ISTC project

NASA Astrophysics Data System (ADS)

Potemkin, A.; Malshakov, Anatoly; Makarov, Alexandr; Krotov, V. A.; Kulikov, Stanislav M.; Sukharev, Stanislav A.

1999-07-01

Technique testing of quality the transparent component of optical devices with application of self-focusing effect is offered. In measurement of small wavefront distortions a method of comparison of laser beam parameters before and after passage of a tested optical element is used. With the purpose of increase of sensitivity it is offered for overcoming negative diffraction action to use self-focusing effect of probe beam. Application of self-focusing effect allows to reach sensitivity no less than (lambda) /600 and in future up to (lambda) /3000. On simple samples experimental checks of a method are made.

Contextualisation in the revised dual representation theory of PTSD: a response to Pearson and colleagues.

PubMed

Brewin, Chris R; Burgess, Neil

2014-03-01

Three recent studies (Pearson, 2012; Pearson, Ross, & Webster, 2012) purported to test the revised dual representation theory of posttraumatic stress disorder (Brewin, Gregory, Lipton, & Burgess, 2010) by manipulating the amount of additional information accompanying traumatic stimulus materials and assessing the effect on subsequent intrusive memories. Here we point out that these studies involve a misunderstanding of the meaning of "contextual" within the theory, such that the manipulation would be unlikely to have had the intended effect and the results are ambiguous with respect to the theory. Past and future experimental tests of the theory are discussed. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Cancer preventive and curative attributes of plants of the Cactaceae family: a review.

PubMed

Harlev, Eli; Nevo, Eviatar; Solowey, Elaine; Bishayee, Anupam

2013-06-01

The ever-increasing occurrence of cancer and the severe side effects and limited efficacy of current cancer chemotherapy based on chemical drugs shift the attention toward drugs of plant origin. The Cactaceae family comprises more than 1500 species, but until recently only a few of them have been tested for their chemopreventive and anticancer attributes, leaving a wide unexplored area still waiting for researchers to investigate. Considering this fact, and also the promising results obtained with the relatively few plants of this family already tested, it should justly be expected that some plants of the Cactaceae family yet unexplored might possess outstanding anticancer attributes, exceeding those displayed by the plants already tested. This review presents in vitro and in vivo experimental evidence on cancer chemopreventive and therapeutic potential of bioactive phytoconstituents and extracts derived from cactus plants. It also examines the underlying biochemical and molecular mechanisms involved in the antineoplastic effects of plants of the Cactaceae family. Current limitation and future directions of research towards effective use of cacti to develop efficient and side effect-free future cancer-preventive and anticancer drugs are also discussed. Georg Thieme Verlag KG Stuttgart · New York.

Development and testing of a double length pets for the CLIC experimental area

NASA Astrophysics Data System (ADS)

Sánchez, L.; Carrillo, D.; Gavela, D.; Lara, A.; Rodríguez, E.; Gutiérrez, J. L.; Calero, J.; Toral, F.; Samoshkin, A.; Gudkov, D.; Riddone, G.

2014-05-01

CLIC (compact linear collider) is a future e+e- collider based on normal-conducting technology, currently under study at CERN. Its design is based on a novel two-beam acceleration scheme. The main beam gets RF power extracted from a drive beam through power extraction and transfer structures (PETS). The technical feasibility of CLIC is currently being proved by its Third Test Facility (CTF3) which includes the CLIC experimental area (CLEX). Two Double Length CLIC PETS will be installed in CLEX to validate their performance with beam. This paper is focused on the engineering design, fabrication and validation of this PETS first prototype. The design consists of eight identical bars, separated by radial slots in which damping material is located to absorb transverse wakefields, and two compact couplers placed at both ends of the bars to extract the generated power. The PETS bars are housed inside a vacuum tank designed to make the PETS as compact as possible. Several joint techniques such as vacuum brazing, electron beam and arc welding were used to complete the assembly. Finally, several tests such as dimensional control and leak testing were carried out to validate design and fabrication methods. In addition, RF measurements at low power were made to study frequency tuning.

Experimental Evaluation of Verification and Validation Tools on Martian Rover Software

NASA Technical Reports Server (NTRS)

Brat, Guillaume; Giannakopoulou, Dimitra; Goldberg, Allen; Havelund, Klaus; Lowry, Mike; Pasareani, Corina; Venet, Arnaud; Visser, Willem; Washington, Rich

2003-01-01

We report on a study to determine the maturity of different verification and validation technologies (V&V) on a representative example of NASA flight software. The study consisted of a controlled experiment where three technologies (static analysis, runtime analysis and model checking) were compared to traditional testing with respect to their ability to find seeded errors in a prototype Mars Rover. What makes this study unique is that it is the first (to the best of our knowledge) to do a controlled experiment to compare formal methods based tools to testing on a realistic industrial-size example where the emphasis was on collecting as much data on the performance of the tools and the participants as possible. The paper includes a description of the Rover code that was analyzed, the tools used as well as a detailed description of the experimental setup and the results. Due to the complexity of setting up the experiment, our results can not be generalized, but we believe it can still serve as a valuable point of reference for future studies of this kind. It did confirm the belief we had that advanced tools can outperform testing when trying to locate concurrency errors. Furthermore the results of the experiment inspired a novel framework for testing the next generation of the Rover.

An Experimental Study of Shear-Dominated Failure in the 2013 Sandia Fracture Challenge Specimen

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

Corona, Edmundo; Deibler, Lisa Anne; Reedlunn, Benjamin

2015-04-01

This report presents an experimental study motivated by results obtained during the 2013 Sandia Fracture Challenge. The challenge involved A286 steel, shear-dominated compression specimens whose load-deflection response contained a load maximum fol- lowed by significant displacement under decreasing load, ending with a catastrophic fracture. Blind numerical simulations deviated from the experiments well before the maximum load and did not predict the failure displacement. A series of new tests were conducted on specimens machined from the original A286 steel stock to learn more about the deformation and failure processes in the specimen and potentially improve future numerical simulations. The study consistedmore » of several uniaxial tension tests to explore anisotropy in the material, and a set of new tests on the compression speci- men. In some compression specimen tests, stereo digital image correlation (DIC) was used to measure the surface strain fields local to the region of interest. In others, the compression specimen was loaded to a given displacement prior to failure, unloaded, sectioned, and imaged under the microscope to determine when material damage first appeared and how it spread. The experiments brought the following observations to light. The tensile tests revealed that the plastic response of the material is anisotropic. DIC during the shear- dominated compression tests showed that all three in-plane surface strain components had maxima in the order of 50% at the maximum load. Sectioning of the specimens revealed no signs of material damage at the point where simulations deviated from the experiments. Cracks and other damage did start to form approximately when the max- imum load was reached, and they grew as the load decreased, eventually culminating in catastrophic failure of the specimens. In addition to the steel specimens, a similar study was carried out for aluminum 7075-T651 specimens. These specimens achieved much lower loads and displacements, and failure occurred very close to the maximum in the load-deflection response. No material damage was observed in these specimens, even when failure was imminent. In the future, we plan to use these experimental results to improve numerical simu- lations of the A286 steel experiments, and to improve plasticity and failure models for the Al 7075 stock. The ultimate goal of our efforts is to increase our confidence in the results of numerical simulations of elastic-plastic structural behavior and failure.« less

Telescope-based cavity for negative ion beam neutralization in future fusion reactors.

PubMed

Fiorucci, Donatella; Hreibi, Ali; Chaibi, Walid

2018-03-01

In future fusion reactors, heating system efficiency is of the utmost importance. Photo-neutralization substantially increases the neutral beam injector (NBI) efficiency with respect to the foreseen system in the International Thermonuclear Experimental Reactor (ITER) based on a gaseous target. In this paper, we propose a telescope-based configuration to be used in the NBI photo-neutralizer cavity of the demonstration power plant (DEMO) project. This configuration greatly reduces the total length of the cavity, which likely solves overcrowding issues in a fusion reactor environment. Brought to a tabletop experiment, this cavity configuration is tested: a 4 mm beam width is obtained within a ≃1.5  m length cavity. The equivalent cavity g factor is measured to be 0.038(3), thus confirming the cavity stability.

Detecting chameleons through Casimir force measurements

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

Brax, Philippe; Bruck, Carsten van de; Davis, Anne-Christine

2007-12-15

The best laboratory constraints on strongly coupled chameleon fields come not from tests of gravity per se but from precision measurements of the Casimir force. The chameleonic force between two nearby bodies is more akin to a Casimir-like force than a gravitational one: The chameleon force behaves as an inverse power of the distance of separation between the surfaces of two bodies, just as the Casimir force does. Additionally, experimental tests of gravity often employ a thin metallic sheet to shield electrostatic forces; however, this sheet masks any detectable signal due to the presence of a strongly coupled chameleon field.more » As a result of this shielding, experiments that are designed to specifically test the behavior of gravity are often unable to place any constraint on chameleon fields with a strong coupling to matter. Casimir force measurements do not employ a physical electrostatic shield and as such are able to put tighter constraints on the properties of chameleons fields with a strong matter coupling than tests of gravity. Motivated by this, we perform a full investigation on the possibility of testing chameleon models with both present and future Casimir experiments. We find that present-day measurements are not able to detect the chameleon. However, future experiments have a strong possibility of detecting or rule out a whole class of chameleon models.« less

Dynamically Hedging Oil and Currency Futures Using Receding Horizontal Control and Stochastic Programming

NASA Astrophysics Data System (ADS)

Cottrell, Paul Edward

There is a lack of research in the area of hedging future contracts, especially in illiquid or very volatile market conditions. It is important to understand the volatility of the oil and currency markets because reduced fluctuations in these markets could lead to better hedging performance. This study compared different hedging methods by using a hedging error metric, supplementing the Receding Horizontal Control and Stochastic Programming (RHCSP) method by utilizing the London Interbank Offered Rate with the Levy process. The RHCSP hedging method was investigated to determine if improved hedging error was accomplished compared to the Black-Scholes, Leland, and Whalley and Wilmott methods when applied on simulated, oil, and currency futures markets. A modified RHCSP method was also investigated to determine if this method could significantly reduce hedging error under extreme market illiquidity conditions when applied on simulated, oil, and currency futures markets. This quantitative study used chaos theory and emergence for its theoretical foundation. An experimental research method was utilized for this study with a sample size of 506 hedging errors pertaining to historical and simulation data. The historical data were from January 1, 2005 through December 31, 2012. The modified RHCSP method was found to significantly reduce hedging error for the oil and currency market futures by the use of a 2-way ANOVA with a t test and post hoc Tukey test. This study promotes positive social change by identifying better risk controls for investment portfolios and illustrating how to benefit from high volatility in markets. Economists, professional investment managers, and independent investors could benefit from the findings of this study.

Scaling Analysis Techniques to Establish Experimental Infrastructure for Component, Subsystem, and Integrated System Testing

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

Sabharwall, Piyush; O'Brien, James E.; McKellar, Michael G.

2015-03-01

Hybrid energy system research has the potential to expand the application for nuclear reactor technology beyond electricity. The purpose of this research is to reduce both technical and economic risks associated with energy systems of the future. Nuclear hybrid energy systems (NHES) mitigate the variability of renewable energy sources, provide opportunities to produce revenue from different product streams, and avoid capital inefficiencies by matching electrical output to demand by using excess generation capacity for other purposes when it is available. An essential step in the commercialization and deployment of this advanced technology is scaled testing to demonstrate integrated dynamic performancemore » of advanced systems and components when risks cannot be mitigated adequately by analysis or simulation. Further testing in a prototypical environment is needed for validation and higher confidence. This research supports the development of advanced nuclear reactor technology and NHES, and their adaptation to commercial industrial applications that will potentially advance U.S. energy security, economy, and reliability and further reduce carbon emissions. Experimental infrastructure development for testing and feasibility studies of coupled systems can similarly support other projects having similar developmental needs and can generate data required for validation of models in thermal energy storage and transport, energy, and conversion process development. Experiments performed in the Systems Integration Laboratory will acquire performance data, identify scalability issues, and quantify technology gaps and needs for various hybrid or other energy systems. This report discusses detailed scaling (component and integrated system) and heat transfer figures of merit that will establish the experimental infrastructure for component, subsystem, and integrated system testing to advance the technology readiness of components and systems to the level required for commercial application and demonstration under NHES.« less

Multi-component testing using HZ-PAN and AgZ-PAN Sorbents for OSPREY Model validation

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

Garn, Troy G.; Greenhalgh, Mitchell; Lyon, Kevin L.

2015-04-01

In efforts to further develop the capability of the Off-gas SeParation and RecoverY (OSPREY) model, multi-component tests were completed using both HZ-PAN and AgZ-PAN sorbents. The primary purpose of this effort was to obtain multi-component xenon and krypton capacities for comparison to future OSPREY predicted multi-component capacities using previously acquired Langmuir equilibrium parameters determined from single component isotherms. Experimental capacities were determined for each sorbent using two feed gas compositions of 1000 ppmv xenon and 150 ppmv krypton in either a helium or air balance. Test temperatures were consistently held at 220 K and the gas flowrate was 50 sccm.more » Capacities were calculated from breakthrough curves using TableCurve® 2D software by Jandel Scientific. The HZ-PAN sorbent was tested in the custom designed cryostat while the AgZ-PAN was tested in a newly installed cooling apparatus. Previous modeling validation efforts indicated the OSPREY model can be used to effectively predict single component xenon and krypton capacities for both engineered form sorbents. Results indicated good agreement with the experimental and predicted capacity values for both krypton and xenon on the sorbents. Overall, the model predicted slightly elevated capacities for both gases which can be partially attributed to the estimation of the parameters and the uncertainty associated with the experimental measurements. Currently, OSPREY is configured such that one species adsorbs and one does not (i.e. krypton in helium). Modification of OSPREY code is currently being performed to incorporate multiple adsorbing species and non-ideal interactions of gas phase species with the sorbent and adsorbed phases. Once these modifications are complete, the sorbent capacities determined in the present work will be used to validate OSPREY multicomponent adsorption predictions.« less

Effects of Aggregation on Blood Sedimentation and Conductivity

PubMed Central

Zhbanov, Alexander; Yang, Sung

2015-01-01

The erythrocyte sedimentation rate (ESR) test has been used for over a century. The Westergren method is routinely used in a variety of clinics. However, the mechanism of erythrocyte sedimentation remains unclear, and the 60 min required for the test seems excessive. We investigated the effects of cell aggregation during blood sedimentation and electrical conductivity at different hematocrits. A sample of blood was drop cast into a small chamber with two planar electrodes placed on the bottom. The measured blood conductivity increased slightly during the first minute and decreased thereafter. We explored various methods of enhancing or retarding the erythrocyte aggregation. Using experimental measurements and theoretical calculations, we show that the initial increase in blood conductivity was indeed caused by aggregation, while the subsequent decrease in conductivity resulted from the deposition of erythrocytes. We present a method for calculating blood conductivity based on effective medium theory. Erythrocytes are modeled as conducting spheroids surrounded by a thin insulating membrane. A digital camera was used to investigate the erythrocyte sedimentation behavior and the distribution of the cell volume fraction in a capillary tube. Experimental observations and theoretical estimations of the settling velocity are provided. We experimentally demonstrate that the disaggregated cells settle much slower than the aggregated cells. We show that our method of measuring the electrical conductivity credibly reflected the ESR. The method was very sensitive to the initial stage of aggregation and sedimentation, while the sedimentation curve for the Westergren ESR test has a very mild slope in the initial time. We tested our method for rapid estimation of the Westergren ESR. We show a correlation between our method of measuring changes in blood conductivity and standard Westergren ESR method. In the future, our method could be examined as a potential means of accelerating ESR tests in clinical practice. PMID:26047511

Objective evaluation of surgical competency for minimally invasive surgery with a collection of simple tests

PubMed Central

Gonzalez-Neira, Eliana Maria; Jimenez-Mendoza, Claudia Patricia; Rugeles-Quintero, Saul

2016-01-01

Objective: This study aims at determining if a collection of 16 motor tests on a physical simulator can objectively discriminate and evaluate practitioners' competency level, i.e. novice, resident, and expert. Methods: An experimental design with three study groups (novice, resident, and expert) was developed to test the evaluation power of each of the 16 simple tests. An ANOVA and a Student Newman-Keuls (SNK) test were used to analyze results of each test to determine which of them can discriminate participants' competency level. Results: Four of the 16 tests used discriminated all of the three competency levels and 15 discriminated at least two of the three groups (α= 0.05). Moreover, other two tests differentiate beginners' level from intermediate, and other seven tests differentiate intermediate level from expert. Conclusion: The competency level of a practitioner of minimally invasive surgery can be evaluated by a specific collection of basic tests in a physical surgical simulator. Reduction of the number of tests needed to discriminate the competency level of surgeons can be the aim of future research. PMID:27226664

Objective evaluation of surgical competency for minimally invasive surgery with a collection of simple tests.

PubMed

Gonzalez-Neira, Eliana Maria; Jimenez-Mendoza, Claudia Patricia; Suarez, Daniel R; Rugeles-Quintero, Saul

2016-03-30

This study aims at determining if a collection of 16 motor tests on a physical simulator can objectively discriminate and evaluate practitioners' competency level, i.e. novice, resident, and expert. An experimental design with three study groups (novice, resident, and expert) was developed to test the evaluation power of each of the 16 simple tests. An ANOVA and a Student Newman-Keuls (SNK) test were used to analyze results of each test to determine which of them can discriminate participants' competency level. Four of the 16 tests used discriminated all of the three competency levels and 15 discriminated at least two of the three groups (α= 0.05). Moreover, other two tests differentiate beginners' level from intermediate, and other seven tests differentiate intermediate level from expert. The competency level of a practitioner of minimally invasive surgery can be evaluated by a specific collection of basic tests in a physical surgical simulator. Reduction of the number of tests needed to discriminate the competency level of surgeons can be the aim of future research.

Constitutive behavior and progressive mechanical failure of electrodes in lithium-ion batteries

NASA Astrophysics Data System (ADS)

Zhang, Chao; Xu, Jun; Cao, Lei; Wu, Zenan; Santhanagopalan, Shriram

2017-07-01

The electrodes of lithium-ion batteries (LIB) are known to be brittle and to fail earlier than the separators during an external crush event. Thus, the understanding of mechanical failure mechanism for LIB electrodes (anode and cathode) is critical for the safety design of LIB cells. In this paper, we present experimental and numerical studies on the constitutive behavior and progression of failure in LIB electrodes. Mechanical tests were designed and conducted to evaluate the constitutive properties of porous electrodes. Constitutive models were developed to describe the stress-strain response of electrodes under uniaxial tensile and compressive loads. The failure criterion and a damage model were introduced to model their unique tensile and compressive failure behavior. The failure mechanism of LIB electrodes was studied using the blunt rod test on dry electrodes, and numerical models were built to simulate progressive failure. The different failure processes were examined and analyzed in detail numerically, and correlated with experimentally observed failure phenomena. The test results and models improve our understanding of failure behavior in LIB electrodes, and provide constructive insights on future development of physics-based safety design tools for battery structures under mechanical abuse.

Constitutive behavior and progressive mechanical failure of electrodes in lithium-ion batteries

DOE PAGES

Zhang, Chao; Xu, Jun; Cao, Lei; ...

2017-05-05

The electrodes of lithium-ion batteries (LIB) are known to be brittle and to fail earlier than the separators during an external crush event. Thus, the understanding of mechanical failure mechanism for LIB electrodes (anode and cathode) is critical for the safety design of LIB cells. In this paper, we present experimental and numerical studies on the constitutive behavior and progression of failure in LIB electrodes. Mechanical tests were designed and conducted to evaluate the constitutive properties of porous electrodes. Constitutive models were developed to describe the stress-strain response of electrodes under uniaxial tensile and compressive loads. The failure criterion andmore » a damage model were introduced to model their unique tensile and compressive failure behavior. The failure mechanism of LIB electrodes was studied using the blunt rod test on dry electrodes, and numerical models were built to simulate progressive failure. The different failure processes were examined and analyzed in detail numerically, and correlated with experimentally observed failure phenomena. Finally, the test results and models improve our understanding of failure behavior in LIB electrodes, and provide constructive insights on future development of physics-based safety design tools for battery structures under mechanical abuse.« less

Development of an Experiment High Performance Nozzle Research Program

NASA Technical Reports Server (NTRS)

2004-01-01

As proposed in the above OAI/NASA Glenn Research Center (GRC) Co-Operative Agreement the objective of the work was to provide consultation and assistance to the NASA GRC GTX Rocket Based Combined Cycle (RBCC) Program Team in planning and developing requirements, scale model concepts, and plans for an experimental nozzle research program. The GTX was one of the launch vehicle concepts being studied as a possible future replacement for the aging NASA Space Shuttle, and was one RBCC element in the ongoing NASA Access to Space R&D Program (Reference 1). The ultimate program objective was the development of an appropriate experimental research program to evaluate and validate proposed nozzle concepts, and thereby result in the optimization of a high performance nozzle for the GTX launch vehicle. Included in this task were the identification of appropriate existing test facilities, development of requirements for new non-existent test rigs and fixtures, develop scale nozzle model concepts, and propose corresponding test plans. Also included were the evaluation of originally proposed and alternate nozzle designs (in-house and contractor), evaluation of Computational Fluid Dynamics (CFD) study results, and make recommendations for geometric changes to result in improved nozzle thrust coefficient performance (Cfg).

Generation 1.5 High Speed Civil Transport (HSCT) Exhaust Nozzle Program

NASA Technical Reports Server (NTRS)

Thayer, E. B.; Gamble, E. J.; Guthrie, A. R.; Kehret, D. F.; Barber, T. J.; Hendricks, G. J.; Nagaraja, K. S.; Minardi, J. E.

2004-01-01

The objective of this program was to conduct an experimental and analytical evaluation of low noise exhaust nozzles suitable for future High-Speed Civil Transport (HSCT) aircraft. The experimental portion of the program involved parametric subscale performance model tests of mixer/ejector nozzles in the takeoff mode, and high-speed tests of mixer/ejectors converted to two-dimensional convergent-divergent (2-D/C-D), plug, and single expansion ramp nozzles (SERN) in the cruise mode. Mixer/ejector results show measured static thrust coefficients at secondary flow entrainment levels of 70 percent of primary flow. Results of the high-speed performance tests showed that relatively long, straight-wall, C-D nozzles could meet supersonic cruise thrust coefficient goal of 0.982; but the plug, ramp, and shorter C-D nozzles required isentropic contours to reach the same level of performance. The computational fluid dynamic (CFD) study accurately predicted mixer/ejector pressure distributions and shock locations. Heat transfer studies showed that a combination of insulation and convective cooling was more effective than film cooling for nonafterburning, low-noise nozzles. The thrust augmentation study indicated potential benefits for use of ejector nozzles in the subsonic cruise mode if the ejector inlet contains a sonic throat plane.

Development and testing of a unique carousel wind tunnel to experimentally determine the effect of gravity and the interparticle force on the physics of wind-blown particles

NASA Technical Reports Server (NTRS)

Leach, R. N.; Greeley, Ronald; White, Bruce R.; Iversen, James D.

1987-01-01

In the study of planetary aeolian processes the effect of gravity is not readily modeled. Gravity appears in the equations of particle motion along with the interparticle forces but the two are not separable. A wind tunnel that perimits multiphase flow experiments with wind blown particles at variable gravity was built and experiments were conducted at reduced gravity. The equations of particle motion initiation (saltation threshold) with variable gravity were experimentally verified and the interparticle force was separated. A uniquely design Carousel Wind Tunnel (CWT) allows for the long flow distance in a small sized tunnel since the test section if a continuous loop and develops the required turbulent boundary layer. A prototype model of the tunnel where only the inner drum rotates was built and tested in the KC-135 Weightless Wonder 4 zero-g aircraft. Future work includes further experiments with walnut shell in the KC-135 which sharply graded particles of widely varying median sizes including very small particles to see how interparticle force varies with particle size, and also experiments with other aeolian material.

Connecting Neurons to a Mobile Robot: An In Vitro Bidirectional Neural Interface

PubMed Central

Novellino, A.; D'Angelo, P.; Cozzi, L.; Chiappalone, M.; Sanguineti, V.; Martinoia, S.

2007-01-01

One of the key properties of intelligent behaviors is the capability to learn and adapt to changing environmental conditions. These features are the result of the continuous and intense interaction of the brain with the external world, mediated by the body. For this reason “embodiment” represents an innovative and very suitable experimental paradigm when studying the neural processes underlying learning new behaviors and adapting to unpredicted situations. To this purpose, we developed a novel bidirectional neural interface. We interconnected in vitro neurons, extracted from rat embryos and plated on a microelectrode array (MEA), to external devices, thus allowing real-time closed-loop interaction. The novelty of this experimental approach entails the necessity to explore different computational schemes and experimental hypotheses. In this paper, we present an open, scalable architecture, which allows fast prototyping of different modules and where coding and decoding schemes and different experimental configurations can be tested. This hybrid system can be used for studying the computational properties and information coding in biological neuronal networks with far-reaching implications for the future development of advanced neuroprostheses. PMID:18350128

Assessment of dependency, agreeableness, and their relationship.

PubMed

Lowe, Jennifer Ruth; Edmundson, Maryanne; Widiger, Thomas A

2009-12-01

Agreeableness is central to the 5-factor model conceptualization of dependency. However, 4 meta-analyses of the relationship of agreeableness with dependency have failed to identify a consistent relationship. It was the hypothesis of the current study that these findings might be due in part to an emphasis on the assessment of adaptive, rather than maladaptive, variants of agreeableness. This hypothesis was tested by using experimentally altered NEO Personality Inventory-Revised (Costa & McCrae, 1992) items that were reversed with respect to their implications for maladaptiveness. The predicted correlations were confirmed with the experimentally altered version with measures of dependent personality disorder, measures of trait dependency (including 2 measures of adaptive dependency), and measures of dependency from alternative dimensional models of personality disorder. The theoretical implications of the findings and suggestions for future research are discussed.

Probing leptophilic dark sectors with hadronic processes

NASA Astrophysics Data System (ADS)

D'Eramo, Francesco; Kavanagh, Bradley J.; Panci, Paolo

2017-08-01

We study vector portal dark matter models where the mediator couples only to leptons. In spite of the lack of tree-level couplings to colored states, radiative effects generate interactions with quark fields that could give rise to a signal in current and future experiments. We identify such experimental signatures: scattering of nuclei in dark matter direct detection; resonant production of lepton-antilepton pairs at the Large Hadron Collider; and hadronic final states in dark matter indirect searches. Furthermore, radiative effects also generate an irreducible mass mixing between the vector mediator and the Z boson, severely bounded by ElectroWeak Precision Tests. We use current experimental results to put bounds on this class of models, accounting for both radiatively induced and tree-level processes. Remarkably, the former often overwhelm the latter.

Installation of automatic control at experimental breeder reactor II

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

Larson, H.A.; Booty, W.F.; Chick, D.R.

1985-08-01

The Experimental Breeder Reactor II (EBR-II) has been modified to permit automatic control capability. Necessary mechanical and electrical changes were made on a regular control rod position; motor, gears, and controller were replaced. A digital computer system was installed that has the programming capability for varied power profiles. The modifications permit transient testing at EBR-II. Experiments were run that increased power linearly as much as 4 MW/s (16% of initial power of 25 MW(thermal)/s), held power constant, and decreased power at a rate no slower than the increase rate. Thus the performance of the automatic control algorithm, the mechanical andmore » electrical control equipment, and the qualifications of the driver fuel for future power change experiments were all demonstrated.« less

Experimental evidence for frequency dependent self-fertilization in the gynodioecious plant, Silene vulgaris.

PubMed

Miyake, Keiko; Olson, Matthew S

2009-06-01

After over a half century of empirical and theoretical research regarding the evolution and maintenance of gynodioecy in plants, unexplored factors influencing the relative fitnesses of females and hermaphrodites remain. Theoretical studies suggest that hermaphrodite self-fertilization (selfing) rate influences the maintenance of gynodioecy and we hypothesized that population sex ratio may influence hermaphrodite selfing rate. An experimental test for frequency-dependent self-fertilization was conducted using replicated populations constructed with different sex ratios of the gynodioecious plant Silene vulgaris. We found that hermaphrodite selfing increased with decreased hermaphrodite frequency, whereas evidence for increased inbreeding depression was equivocal. We argue that incorporation of context dependent inbreeding into future models of the evolution of gynodioecy is likely to yield novel insights into sex ratio evolution.

Probing leptophilic dark sectors with hadronic processes

DOE PAGES

D'Eramo, Francesco; Kavanagh, Bradley J.; Panci, Paolo

2017-05-29

We study vector portal dark matter models where the mediator couples only to leptons. In spite of the lack of tree-level couplings to colored states, radiative effects generate interactions with quark fields that could give rise to a signal in current and future experiments. We identify such experimental signatures: scattering of nuclei in dark matter direct detection; resonant production of lepton–antilepton pairs at the Large Hadron Collider; and hadronic final states in dark matter indirect searches. Furthermore, radiative effects also generate an irreducible mass mixing between the vector mediator and the Z boson, severely bounded by ElectroWeak Precision Tests. Wemore » use current experimental results to put bounds on this class of models, accounting for both radiatively induced and tree-level processes. Remarkably, the former often overwhelm the latter.« less

[Products toxic to reproduction used in the occupational environment: Definition, risk assessment, classification].

PubMed

Lafon, D

2006-10-01

European regulations (transcribed into French law) aimed at protecting employees from chemicals toxic to reproduction enable classification and labelling of such substances, if they are liable to cause an alteration of male or female reproductive functions or capacity, or to induce non-hereditary harmful effects on their offspring. Three categories can be used to classify these substances in two areas, namely their impairment of fertility and their effects on development. This classification is rarely based on epidemiological study results, but most often on those of experimental toxicological studies conducted by substance manufacturers. These reproduction toxicological studies are only compulsory above a certain tonnage placed on the market. The high level of this tonnage means that these tests are effectively only conducted on rare occasions. It is reckoned that there is no reproduction experimental data for over 95% of substances newly placed on the market. These products therefore appear to be reproduction non-toxic only because they have not been tested. This is a major fault in the current labelling system, which does not allow non-toxic products to be differentiated from non-tested products. The future EU regulatory framework for Registration, Evaluation and Authorisation of CHemicals (REACH) will only slightly enhance information in this area. It can be estimated that over 80% of chemical products will not be exhaustively tested for reproduction and nearly 75% will not be tested to any degree.

A computerized stroop test for the evaluation of psychotropic drugs in healthy participants.

PubMed

Pilli, Raveendranadh; Naidu, Mur; Pingali, Usha Rani; Shobha, J C; Reddy, A Praveen

2013-04-01

The Stroop paradigm evaluates susceptibility to interference and is sensitive to dysfunction in frontal lobes and drug effects. The aim of the present study was to establish a simple and reliable computerized version of Stroop color-word test, which can be used for screening of various psychotropic drugs. The standardized method was followed in all cases, by recording the reaction time (RT) in msec in 24 healthy participants using computerized version of Stroop color-word test. Reproducibility of the test procedure was evaluated by recording the RTs by a single experimenter on two sessions (interday reproducibility). Validity of the model was further tested by evaluating the psychotropic effect of Zolpidem 5 mg, Caffeine 500 mg, or Placebo on 24 healthy subjects in a randomized, double blind three-way crossover design. The method was found to produce low variability with coefficient of variation less than 10%. Interday reproducibility was very good as shown by Bland-Altman plot with most of the values within ±2SD. There was a significant increase in RTs in Stroop performance with Zolpidem at 1 hr and 2 hrs; in contrast, caffeine significantly decreased RTs in Stroop performance at 1 hr only compared to placebo. The Stroop color-word recording and analysis system is simple, sensitive to centrally acting drug effects, and has potential for future experimental psychomotor assessment studies.

Hardware Progress Made in the Early Flight Fission Test Facilities (EFF-TF) To Support Near-Term Space Fission Systems

NASA Astrophysics Data System (ADS)

Van Dyke, Melissa; Martin, James

2005-02-01

The NASA Marshall Space Flight Center's Early Flight Fission Test Facility (EFF-TF), provides a facility to experimentally evaluate nuclear reactor related thermal hydraulic issues through the use of non-nuclear testing. This facility provides a cost effective method to evaluate concepts/designs and support mitigation of developmental risk. Electrical resistance thermal simulators can be used to closely mimic the heat deposition of the fission process, providing axial and radial profiles. A number of experimental and design programs were underway in 2004 which include the following. Initial evaluation of the Department of Energy Los Alamos National Laboratory 19 module stainless steel/sodium heat pipe reactor with integral gas heat exchanger was operated at up to 17.5 kW of input power at core temperatures of 1000 K. A stainless steel sodium heat pipe module was placed through repeated freeze/thaw cyclic testing accumulating over 200 restarts to a temperature of 1000 K. Additionally, the design of a 37- pin stainless steel pumped sodium/potassium (NaK) loop was finalized and components procured. Ongoing testing at the EFF-TF is geared towards facilitating both research and development necessary to support future decisions regarding potential use of space nuclear systems for space exploration. All efforts are coordinated with DOE laboratories, industry, universities, and other NASA centers. This paper describes some of the 2004 efforts.

2000 NASA Seal/Secondary Air System Workshop. Volume 1

NASA Technical Reports Server (NTRS)

Steinetz, Bruce M. (Editor); Hendricks, Robert C. (Editor)

2001-01-01

The 2000 NASA Seal/Secondary Air System Workshop covered four main areas: (1) overviews of NASA-sponsored Ultra-Efficient Engine Technology (UEET) and Access to Space Programs, with emphasis on program goals and seal needs; (2) review of turbine engine seal issues from the perspective of end users such as United Airlines; (3) reviews of sealing concepts, test results, experimental facilities, and numerical predictions; and (4) reviews of material development programs relevant to advanced seals development. The NASA UEET overview illustrates for the reader the importance of advanced technologies, including seals, in meeting future engine system efficiency and emission goals. GE, Pratt & Whitney, and Honeywell presented advanced seal development work being performed within their organizations. The NASA-funded GE/Stein Seal team has successfully demonstrated a large (3-ft. diam) aspirating seal that can withstand all anticipated pressures, speeds, and rotor runouts anticipated for a GE90 L.P. turbine balance piston location. GE/Stein Seal are fabricating a full-scale seal to be tested in a GE-90 ground test engine in early 2002. Pratt & Whitney and Stein Seal are investigating carbon seals to accommodate large radial movements anticipated in future geared-fan gearbox locations. Honeywell presented a finger seal design being considered for a high-temperature static combustor location incorporating ceramic finger elements. Successful demonstration of the braided carbon rope thermal barriers to extreme temperatures (5500 F) for short durations provide a new form of very high temperature thermal barrier for future Shuttle solid rocket motor nozzle joints. The X-37, X-38, and future highly reusable launch vehicles pose challenging control surface seal demands that require new seal concepts made from emerging high temperature ceramics and other materials.

Experimental Testing and Modeling of a Pneumatic Regolith Delivery System for ISRU

NASA Technical Reports Server (NTRS)

Santiago-Maldonado, Edgardo; Dominquez, Jesus A.; Mantovani, James G.

2011-01-01

Excavating and transporting planetary regolith are examples of surface activities that may occur during a future space exploration mission to a planetary body. Regolith, whether it is collected on the Moon, Mars or even an asteroid, consists of granular minerals, some of which have been identified to be viable resources that can be mined and processed chemically to extract useful by-products, such as oxygen, water, and various metals and metal alloys. Even the depleted "waste" material from such chemical processes may be utilized later in the construction of landing pads and protective structures at the site of a planetary base. One reason for excavating and conveying planetary regolith is to deliver raw regolith material to in-situ resource utilization (ISRU) systems. The goal of ISRU is to provide expendable supplies and materials at the planetary destination, if possible. An in-situ capability of producing mission-critical substances such as oxygen will help to extend the mission and its success, and will greatly lower the overall cost of a mission by either eliminating, or significantly reducing, the need to transport the same expendable materials from the Earth. In order to support the goals and objectives of present and future ISRU projects, NASA seeks technology advancements in the areas of regolith conveying. Such systems must be effective, efficient and provide reliable performance over long durations while being exposed to the harsh environments found on planetary surfaces. These conditions include contact with very abrasive regolith particulates, exposure to high vacuum or dry (partial) atmospheres, wide variations in temperature, reduced gravity, and exposure to space radiation. Regolith conveying techniques that combine reduced failure modes and low energy consumption with high material transfer rates will provide significant value for future space exploration missions to the surfaces of the moon, Mars and asteroids. Pneumatic regolith conveying has demonstrated itself to be a viable delivery system through testing under terrestrial and reduced gravity conditions in recent years. Modeling and experimental testing have been conducted at NASA Kennedy Space Center to study and advance pneumatic planetary regolith delivery systems in support of NASA's ISRU project. The goal of this work is to use the model to predict solid-gas flow patterns in reduced gravity environments for ISRU inlet gas line allowing the eductor inlet gas flow to vary and depend on the flow pattern developed at the eductor as inferred by the experimental observations.

Gender differences in learning physical science concepts: Does computer animation help equalize them?

NASA Astrophysics Data System (ADS)

Jacek, Laura Lee

This dissertation details an experiment designed to identify gender differences in learning using three experimental treatments: animation, static graphics, and verbal instruction alone. Three learning presentations were used in testing of 332 university students. Statistical analysis was performed using ANOVA, binomial tests for differences of proportion, and descriptive statistics. Results showed that animation significantly improved women's long-term learning over static graphics (p = 0.067), but didn't significantly improve men's long-term learning over static graphics. In all cases, women's scores improved with animation over both other forms of instruction for long-term testing, indicating that future research should not abandon the study of animation as a tool that may promote gender equity in science. Short-term test differences were smaller, and not statistically significant. Variation present in short-term scores was related more to presentation topic than treatment. This research also details characteristics of each of the three presentations, to identify variables (e.g. level of abstraction in presentation) affecting score differences within treatments. Differences between men's and women's scores were non-standard between presentations, but these differences were not statistically significant (long-term p = 0.2961, short-term p = 0.2893). In future research, experiments might be better designed to test these presentational variables in isolation, possibly yielding more distinctive differences between presentational scores. Differences in confidence interval overlaps between presentations suggested that treatment superiority may be somewhat dependent on the design or topic of the learning presentation. Confidence intervals greatly overlap in all situations. This undercut, to some degree, the surety of conclusions indicating superiority of one treatment type over the others. However, confidence intervals for animation were smaller, overlapped nearly completely for men and women (there was less overlap between the genders for the other two treatments), and centered around slightly higher means, lending further support to the conclusion that animation helped equalize men's and women's learning. The most important conclusion identified in this research is that gender is an important variable experimental populations testing animation as a learning device. Averages indicated that both men and women prefer to work with animation over either static graphics or verbal instruction alone.

The Architecture and Application of RAMSES, a CCSDS and ECSS PUS Compliant Test and Control System

NASA Astrophysics Data System (ADS)

Battelino, Milan; Svard, Christian; Carlsson, Anna; Carlstedt-Duke, Theresa; Tornqvist, Marcus

2010-08-01

SSC, Swedish Space Corporation, has more than 30 years of experience in developing test and control systems for sounding rockets, experimental test modules and satellites. The increasing amount of ongoing projects made SSC to consider developing a test and control system conformant to CCSDS (Consultative Committee for Space Data Systems) and ECSS (European Cooperation for Space Standardization), that with small effort and cost, could be reused between separate projects and products. The foreseen reduction in cost and development time for different future space-related projects made such a reusable control system desirable. This paper will describe the ideas behind the RAMSES (Rocket and Multi-Satellite EMCS Software) system, its architecture and how it has been and is being used in a variety of applications at SSC such as the multi-satellite mission PRISMA and sounding rocket project MAXUS-8.

Foil Bearing Coating Behavior in CO 2

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

Walker, Matthew; Kruizenga, Alan Michael; Pasch, James Jay

2017-08-01

The Sandia S-CO 2 Recompression Closed Brayton Cycle (RCBC) utilizes a series of gas foil bearings in its turbine-alternator-compressors. At high shaft rotational speed these bearings allow the shaft to ride on a cushion of air. Conversely, during startup and shutdown, the shaft rides along the foil bearing surface. Low-friction coatings are used on bearing surfaces in order to facilitate rotation during these periods. An experimental program was initiated to elucidate the behavior of coated bearing foils in the harsh environments of this system. A test configuration was developed enabling long duration exposure tests, followed by a range of analysesmore » relevant to their performance in a bearing. This report provides a detailed overview of this work. The results contained herein provide valuable information in selecting appropriate coatings for more advanced future bearing-rig tests at the newly established test facility in Sandia-NM.« less

Plasma Vehicle Charging Analysis for Orion Flight Test 1

NASA Technical Reports Server (NTRS)

Lallement, L.; McDonald, T.; Norgard, J.; Scully, B.

2014-01-01

In preparation for the upcoming experimental test flight for the Orion crew module, considerable interest was raised over the possibility of exposure to elevated levels of plasma activity and vehicle charging both externally on surfaces and internally on dielectrics during the flight test orbital operations. Initial analysis using NASCAP-2K indicated very high levels of exposure, and this generated additional interest in refining/defining the plasma and spacecraft models used in the analysis. This refinement was pursued, resulting in the use of specific AE8 and AP8 models, rather than SCATHA models, as well as consideration of flight trajectory, time duration, and other parameters possibly affecting the levels of exposure and the magnitude of charge deposition. Analysis using these refined models strongly indicated that, for flight test operations, no special surface coatings were necessary for the thermal protection system, but would definitely be required for future GEO, trans-lunar, and extra-lunar missions...

Plasma Vehicle Charging Analysis for Orion Flight Test 1

NASA Technical Reports Server (NTRS)

Scully, B.; Norgard, J.

2015-01-01

In preparation for the upcoming experimental test flight for the Orion crew module, considerable interest was raised over the possibility of exposure to elevated levels of plasma activity and vehicle charging both externally on surfaces and internally on dielectrics during the flight test orbital operations. Initial analysis using NASCAP-2K indicated very high levels of exposure, and this generated additional interest in refining/defining the plasma and spacecraft models used in the analysis. This refinement was pursued, resulting in the use of specific AE8 and AP8 models, rather than SCATHA models, as well as consideration of flight trajectory, time duration, and other parameters possibly affecting the levels of exposure and the magnitude of charge deposition. Analysis using these refined models strongly indicated that, for flight test operations, no special surface coatings were necessary for the Thermal Protection System (TPS), but would definitely be required for future GEO, trans-lunar, and extra-lunar missions.

The impact of football training on motor development in male children.

PubMed

Erceg, Marko; Zagorac, Nebojsa; Katić, Ratko

2008-03-01

The aim of the study was to determine the effect of football school program and physical education curriculum on changes in the motor abilities of 7- and 8-year-old boys. The study included a sample of 180 boys divided into group 1 (7-year-old boys), subdivided to experimental (n = 40) and control (n = 50) groups, and group 2 (8-year-old boys), subdivided to experimental (n = 40) and control (n = 50) groups. Experimental groups included children attending three training units of football training over a 9-month period, in addition to the conventional physical education curriculum. Control groups included children attending only conventional physical education curriculum. All study subjects underwent testing with a battery of 12 motor tests at the beginning and at the end of the study. Results obtained by discriminative canonic analysis showed no statistically significant between-group difference in motor abilities at the beginning of the study. However, significant differences in favor of experimental groups were recorded at the end of the study. Favorable changes in all motor variables were observed in both experimental and control groups of children from the initial through the final state. These changes were more pronounced in experimental groups. Analysis of variance for difference variables (final to initial measurement) indicated programmed education in the form of football training in addition to regular physical education curriculum to predominantly influence the development of aerobic endurance, agility, speed and flexibility in 7-year-old boys, and of explosive strength, aerobic endurance, flexibility and speed in 8-year-old boys. In the latter, football training led to the formation of a motor complex integrating explosiveness, speed, coordination, endurance and flexibility as a general motor factor determining future quality development in football.

Quasi-experimental nonequivalent (pretest and posttest) control-group study of the effects of microcomputer-based laboratory systems on academic achievement in high school chemistry students at two South Carolina high schools

NASA Astrophysics Data System (ADS)

Venables, Jeffrey M.

The literature on microcomputer-based laboratories (MBL) lacks quantitative studies that measure the effect of MBL on student achievement. The purpose of this study was to investigate the effect of MBL systems on the achievement of high school chemistry students. The first research question examined the effect of MBL systems on student achievement in high school chemistry laboratories. The second question analyzed the effect of MBL systems on the academic achievement of students of different genders, ethnicities, and socioeconomic backgrounds. This quasi-experimental quantitative research study evaluated the effects of MBL on student achievement in high school chemistry. The sample consisted of 124 college preparatory chemistry students at two high schools in a South Carolina school district. There were 42 participants in the experimental group and 82 participants in the control group. Both experimental and groups completed a pre- and post-test with MBL being the independent variable. The mean difference score for the experimental group was compared to that of the control group using an independent-measures t test and an analysis of variance. For the second research question, results were analyzed using a two-factor analysis of variance. Participant scores were broken down by gender, ethnicity, and socioeconomic status in order to identify potential differences. The results revealed no significant differences between the experimental and control groups, and no significant differences in effects of MBL on different segments of the population. Future studies should examine students using MBL for longer durations than one unit of study. As society continues to make technological advances, the effective assessment and implementation of technology resources for the classroom are becoming increasingly important.

Current and Future Research in Active Control of Lightweight, Flexible Structures Using the X-56 Aircraft

NASA Technical Reports Server (NTRS)

Ryan, John J.; Bosworth, John T.; Burken, John J.; Suh, Peter M.

2014-01-01

The X-56 Multi-Utility Technology Testbed aircraft system is a versatile experimental research flight platform. The system was primarily designed to investigate active control of lightweight flexible structures, but is reconfigurable and capable of hosting a wide breadth of research. Current research includes flight experimentation of a Lockheed Martin designed active control flutter suppression system. Future research plans continue experimentation with alternative control systems, explore the use of novel sensor systems, and experiments with the use of novel control effectors. This paper describes the aircraft system, current research efforts designed around the system, and future planned research efforts that will be hosted on the aircraft system.

Space Software Defined Radio Characterization to Enable Reuse

NASA Technical Reports Server (NTRS)

Mortensen, Dale J.; Bishop, Daniel W.; Chelmins, David

2012-01-01

NASA's Space Communication and Navigation Testbed is beginning operations on the International Space Station this year. The objective is to promote new software defined radio technologies and associated software application reuse, enabled by this first flight of NASA's Space Telecommunications Radio System architecture standard. The Space Station payload has three software defined radios onboard that allow for a wide variety of communications applications; however, each radio was only launched with one waveform application. By design the testbed allows new waveform applications to be uploaded and tested by experimenters in and outside of NASA. During the system integration phase of the testbed special waveform test modes and stand-alone test waveforms were used to characterize the SDR platforms for the future experiments. Characterization of the Testbed's JPL SDR using test waveforms and specialized ground test modes is discussed in this paper. One of the test waveforms, a record and playback application, can be utilized in a variety of ways, including new satellite on-orbit checkout as well as independent on-board testbed experiments.

Public reaction to direct-to-consumer online genetic tests: Comparing attitudes, trust and intentions across commercial and conventional providers.

PubMed

Critchley, Christine; Nicol, Dianne; Otlowski, Margaret; Chalmers, Don

2015-08-01

The success of personalised medicine depends upon the public's embracing genetic tests. Tests that claim to predict an individual's future health can now be accessed via online companies outside of conventional health regulations. This research assessed the extent to which the public embrace direct-to-consumer (DTC) genetic tests relative to those obtained by a conventional medical practitioner (MP). It also examined the reasons for differences across providers using a randomised experimental telephone survey of 1000 Australians. Results suggest that people were significantly less likely to approve of, and order a DTC genetic test administered by a company compared to a MP because they were less trusting of companies' being able to protect their privacy and provide them with access to genetic expertise and counselling. Markets for DTC genetic tests provided by companies would therefore significantly increase if trust in privacy protection and access to expertise are enhanced through regulation. © The Author(s) 2014.

Consensus report on the future of animal-free systemic toxicity testing.

PubMed

Leist, Marcel; Hasiwa, Nina; Rovida, Costanza; Daneshian, Mardas; Basketter, David; Kimber, Ian; Clewell, Harvey; Gocht, Tilman; Goldberg, Alan; Busquet, Francois; Rossi, Anna-Maria; Schwarz, Michael; Stephens, Martin; Taalman, Rob; Knudsen, Thomas B; McKim, James; Harris, Georgina; Pamies, David; Hartung, Thomas

2014-01-01

Since March 2013, animal use for cosmetics testing for the European market has been banned. This requires a renewed view on risk assessment in this field. However, in other fields as well, traditional animal experimentation does not always satisfy requirements in safety testing, as the need for human-relevant information is ever increasing. A general strategy for animal-free test approaches was outlined by the US National Research Council`s vision document for Toxicity Testing in the 21st Century in 2007. It is now possible to provide a more defined roadmap on how to implement this vision for the four principal areas of systemic toxicity evaluation: repeat dose organ toxicity, carcinogenicity, reproductive toxicity and allergy induction (skin sensitization), as well as for the evaluation of toxicant metabolism (toxicokinetics) (Fig. 1). CAAT-Europe assembled experts from Europe, America and Asia to design a scientific roadmap for future risk assessment approaches and the outcome was then further discussed and refined in two consensus meetings with over 200 stakeholders. The key recommendations include: focusing on improving existing methods rather than favoring de novo design; combining hazard testing with toxicokinetics predictions; developing integrated test strategies; incorporating new high content endpoints to classical assays; evolving test validation procedures; promoting collaboration and data-sharing of different industrial sectors; integrating new disciplines, such as systems biology and high throughput screening; and involving regulators early on in the test development process. A focus on data quality, combined with increased attention to the scientific background of a test method, will be important drivers. Information from each test system should be mapped along adverse outcome pathways. Finally, quantitative information on all factors and key events will be fed into systems biology models that allow a probabilistic risk assessment with flexible adaptation to exposure scenarios and individual risk factors.

First steps in experimental cancer evolution

PubMed Central

Taylor, Tiffany B; Johnson, Louise J; Jackson, Robert W; Brockhurst, Michael A; Dash, Philip R

2013-01-01

Evolutionary processes play a central role in the development, progression and response to treatment of cancers. The current challenge facing researchers is to harness evolutionary theory to further our understanding of the clinical progression of cancers. Central to this endeavour will be the development of experimental systems and approaches by which theories of cancer evolution can be effectively tested. We argue here that the experimental evolution approach – whereby evolution is observed in real time and which has typically employed microorganisms – can be usefully applied to cancer. This approach allows us to disentangle the ecological causes of natural selection, identify the genetic basis of evolutionary changes and determine their repeatability. Cell cultures used in cancer research share many of the desirable traits that make microorganisms ideal for studying evolution. As such, experimental cancer evolution is feasible and likely to give great insight into the selective pressures driving the evolution of clinically destructive cancer traits. We highlight three areas of evolutionary theory with importance to cancer biology that are amenable to experimental evolution: drug resistance, social evolution and resource competition. Understanding the diversity, persistence and evolution of cancers is vital for treatment and drug development, and an experimental evolution approach could provide strategic directions and focus for future research. PMID:23745144

The Academy for Future Science Faculty: randomized controlled trial of theory-driven coaching to shape development and diversity of early-career scientists.

PubMed

Thakore, Bhoomi K; Naffziger-Hirsch, Michelle E; Richardson, Jennifer L; Williams, Simon N; McGee, Richard

2014-08-02

Approaches to training biomedical scientists have created a talented research community. However, they have failed to create a professional workforce that includes many racial and ethnic minorities and women in proportion to their representation in the population or in PhD training. This is particularly true at the faculty level. Explanations for the absence of diversity in faculty ranks can be found in social science theories that reveal processes by which individuals develop identities, experiences, and skills required to be seen as legitimate within the profession. Using the social science theories of Communities of Practice, Social Cognitive Career Theory, identity formation, and cultural capital, we have developed and are testing a novel coaching-based model to address some of the limitations of previous diversity approaches. This coaching intervention (The Academy for Future Science Faculty) includes annual in-person meetings of students and trained faculty Career Coaches, along with ongoing virtual coaching, group meetings and communication. The model is being tested as a randomized controlled trial with two cohorts of biomedical PhD students from across the U.S., one recruited at the start of their PhDs and one nearing completion. Stratification into the experimental and control groups, and to coaching groups within the experimental arms, achieved equal numbers of students by race, ethnicity and gender to the extent possible. A fundamental design element of the Academy is to teach and make visible the social science principles which highly influence scientific advancement, as well as acknowledging the extra challenges faced by underrepresented groups working to be seen as legitimate within the scientific communities. The strategy being tested is based upon a novel application of the well-established principles of deploying highly skilled coaches, selected and trained for their ability to develop talents of others. This coaching model is intended to be a complement, rather than a substitute, for traditional mentoring in biomedical research training, and is being tested as such.

Contemporary Impact Analysis Methodology for Planetary Sample Return Missions

NASA Technical Reports Server (NTRS)

Perino, Scott V.; Bayandor, Javid; Samareh, Jamshid A.; Armand, Sasan C.

2015-01-01

Development of an Earth entry vehicle and the methodology created to evaluate the vehicle's impact landing response when returning to Earth is reported. NASA's future Mars Sample Return Mission requires a robust vehicle to return Martian samples back to Earth for analysis. The Earth entry vehicle is a proposed solution to this Mars mission requirement. During Earth reentry, the vehicle slows within the atmosphere and then impacts the ground at its terminal velocity. To protect the Martian samples, a spherical energy absorber called an impact sphere is under development. The impact sphere is composed of hybrid composite and crushable foam elements that endure large plastic deformations during impact and cause a highly nonlinear vehicle response. The developed analysis methodology captures a range of complex structural interactions and much of the failure physics that occurs during impact. Numerical models were created and benchmarked against experimental tests conducted at NASA Langley Research Center. The postimpact structural damage assessment showed close correlation between simulation predictions and experimental results. Acceleration, velocity, displacement, damage modes, and failure mechanisms were all effectively captured. These investigations demonstrate that the Earth entry vehicle has great potential in facilitating future sample return missions.

Rocket Engine Turbine Blade Surface Pressure Distributions Experiment and Computations

NASA Technical Reports Server (NTRS)

Hudson, Susan T.; Zoladz, Thomas F.; Dorney, Daniel J.; Turner, James (Technical Monitor)

2002-01-01

Understanding the unsteady aspects of turbine rotor flow fields is critical to successful future turbine designs. A technology program was conducted at NASA's Marshall Space Flight Center to increase the understanding of unsteady environments for rocket engine turbines. The experimental program involved instrumenting turbine rotor blades with miniature surface mounted high frequency response pressure transducers. The turbine model was then tested to measure the unsteady pressures on the rotor blades. The data obtained from the experimental program is unique in two respects. First, much more unsteady data was obtained (several minutes per set point) than has been possible in the past. Also, an extensive steady performance database existed for the turbine model. This allowed an evaluation of the effect of the on-blade instrumentation on the turbine's performance. A three-dimensional unsteady Navier-Stokes analysis was also used to blindly predict the unsteady flow field in the turbine at the design operating conditions and at +15 degrees relative incidence to the first-stage rotor. The predicted time-averaged and unsteady pressure distributions show good agreement with the experimental data. This unique data set, the lessons learned for acquiring this type of data, and the improvements made to the data analysis and prediction tools are contributing significantly to current Space Launch Initiative turbine airflow test and blade surface pressure prediction efforts.

Experimental study of a sustainable hybrid system for thermoelectric generation and freshwater production

NASA Astrophysics Data System (ADS)

de Souza, Gabriel Fernandes; Tan, Lippong; Singh, Baljit; Ding, Lai Chet; Date, Abhijit

2017-04-01

The paper presents a sustainable hybrid system, which is capable of generating electricity and producing freshwater from seawater using low grade heat source. This proposed system uses low grade heat that can be supplied from solar radiation, industrial waste heat or any other waste heat sources where the temperature is less than 150°C. The concept behind this system uses the Seebeck effect for thermoelectricity generation via incorporating the low boiling point of seawater under sub-atmospheric ambient pressure. A lab-test prototype of the proposed system was built and experimentally tested in RMIT University. The prototype utilised four commercial available thermoelectric generators (Bi2Te3) and a vacuum vessel to achieve the simultaneous production of electricity and freshwater. The temperature profiles, thermoelectric powers and freshwater productions were determined at several levels of salinity to study the influence of different salt concentrations. The theoretical description of system design and experimental results were analysed and discussed in detailed. The experiment results showed that 0.75W of thermoelectricity and 404g of freshwater were produced using inputs of 150W of simulated waste heat and 500g of 3% saline water. The proposed hybrid concept has demonstrated the potential to become the future sustainable system for electricity and freshwater productions.

Experimental Measurements of the Secondary Electron Yield in the Experimental Measurement of the Secondary Electron Yield in the PEP-II Particle Accelerator Beam Line

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

Pivi, M.T.F.; Collet, G.; King, F.

Beam instability caused by the electron cloud has been observed in positron and proton storage rings and it is expected to be a limiting factor in the performance of the positron Damping Ring (DR) of future Linear Colliders (LC) such as ILC and CLIC. To test a series of promising possible electron cloud mitigation techniques as surface coatings and grooves, in the Positron Low Energy Ring (LER) of the PEP-II accelerator, we have installed several test vacuum chambers including (i) a special chamber to monitor the variation of the secondary electron yield of technical surface materials and coatings under themore » effect of ion, electron and photon conditioning in situ in the beam line; (ii) chambers with grooves in a straight magnetic-free section; and (iii) coated chambers in a dedicated newly installed 4-magnet chicane to study mitigations in a magnetic field region. In this paper, we describe the ongoing R&D effort to mitigate the electron cloud effect for the LC damping ring, focusing on the first experimental area and on results of the reduction of the secondary electron yield due to in situ conditioning.« less

Corner Wrinkling at a Square Membrane Due to Symmetric Mechanical Loads

NASA Technical Reports Server (NTRS)

Blandino, Joseph R.; Johnston, John D.; Dharamsi, Urmil K.; Brodeur, Stephen J. (Technical Monitor)

2001-01-01

Thin-film membrane structures are under consideration for use in many future gossamer spacecraft systems. Examples include sunshields for large aperture telescopes, solar sails, and membrane optics. The development of capabilities for testing and analyzing pre-tensioned, thin film membrane structures is an important and challenging aspect of gossamer spacecraft technology development. This paper presents results from experimental and computational studies performed to characterize the wrinkling behavior of thin-fi[m membranes under mechanical loading. The test article is a 500 mm square membrane subjected to symmetric comer loads. Data is presented for loads ranging from 0.49 N to 4.91 N. The experimental results show that as the load increases the number of wrinkles increases, while the wrinkle amplitude decreases. The computational model uses a finite element implementation of Stein-Hedgepeth membrane wrinkling theory to predict the behavior of the membrane. Comparisons were made with experimental results for the wrinkle angle and wrinkled region. There was reasonably good agreement between the measured wrinkle angle and the predicted directions of the major principle stresses. The shape of the wrinkle region predicted by the finite element model matches that observed in the experiments; however, the size of the predicted region is smaller than that determined in the experiments.

Experimental and Computational Evaluation of Flush-Mounted, S-Duct Inlets

NASA Technical Reports Server (NTRS)

Berrier, Bobby L.; Allan, Brian G.

2004-01-01

A new high Reynolds number test capability for boundary layer ingesting inlets has been developed for the NASA Langley Research Center 0.3-Meter Transonic Cryogenic Tunnel. Using this new capability. an experimental investigation of four S-duct inlet configurations was conducted. A computational study of one of the inlets was also conducted using a Navier-Stokes solver. The objectives of this investigation were to: 1) develop a new high Reynolds number inlet test capability for flush-mounted inlets; 2) provide a database for CFD tool validation; 3) evaluate the performance of S-duct inlets with large amounts of boundary layer ingestion; and 4) provide a baseline inlet for future inlet flow-control studies. Tests were conducted at Mach numbers from 0.25 to 0.83. Reynolds numbers (based on duct exit diameter) from 5.1 million to a full-scale value of 13.9 million, and inlet mass-flow ratios from 0.39 to 1.58 depending on Mach number. Results of the experimental study indicate that inlet pressure recovery generally decreased and inlet distortion generally increased with increasing Mach number. Except at low Mach numbers, increasing inlet mass-flow increased pressure recovery and increased distortion. Increasing the amount of boundary layer ingestion or ingesting a boundary layer with a distorted profile decreased pressure recovery and increased distortion. Finally, increasing Reynolds number had almost no effect on inlet distortion but increased inlet recovery by about one-half percent at a Mach number near cruise. The computational results captured the inlet pressure recovery and distortion trends with Mach number and inlet mass-flow well: the reversal of the pressure recovery trend with increasing inlet mass-flow at low and high Mach numbers was predicted by CFD. However, CFD results were generally more pessimistic (larger losses) than measured experimentally.

Effects of an Interactive School-Based Program for Preventing Adolescent Sexual Harassment: A Cluster-Randomized Controlled Evaluation Study.

PubMed

de Lijster, Gaby P A; Felten, Hanneke; Kok, Gerjo; Kocken, Paul L

2016-05-01

Many adolescents experience sexual harassment and victims of sexual harassment have higher risks regarding well-being and health behaviors such as higher risks of suicidal thoughts, suicidal ideation and feeling unsafe at school. A peer-performed play and school lessons on preventing sexual harassment behavior were presented to secondary school students. We evaluated its effectiveness, using a cluster-randomized controlled design to assign schools to an experimental condition [n = 14 schools; 431 students (51 % female)] and a control condition [n = 11 schools; 384 students (51 % female)]. To measure the effects of the intervention at first post-test and 6-month follow-up, our multilevel analyses used a two-level random intercept model. Outcome measures were sexual harassment behaviors, behavioral determinants and distal factors influencing these behaviors. At post-test, students in the experimental group reported a reduced intention to commit sexual harassment behavior and higher self-efficacy in rejecting it. At post-test and follow-up there was a significant positive effect on social norms for rejecting sexual harassment behavior. At follow-up, sexual self-esteem was higher in students in the experimental group than in the control group. Effects on these determinants will benefit adolescents' future sexual behaviors. In combination, the play and lessons, possibly together with continued sexual health education and skills programs on social-emotional learning in subsequent school years, have potential for preventing sexual harassment behavior.

Modeling, fabrication and plasma actuator coupling of flexible pressure sensors for flow separation detection and control in aeronautical applications

NASA Astrophysics Data System (ADS)

Francioso, L.; De Pascali, C.; Pescini, E.; De Giorgi, M. G.; Siciliano, P.

2016-06-01

Preventing the flow separation could enhance the performance of propulsion systems and future civil aircraft. To this end, a fast detection of boundary layer separation is mandatory for a sustainable and successful application of active flow control devices, such as plasma actuators. The present work reports on the design, fabrication and functional tests of low-cost capacitive pressure sensors coupled with dielectric barrier discharge (DBD) plasma actuators to detect and then control flow separation. Finite element method (FEM) simulations were used to obtain information on the deflection and the stress distribution in different-shaped floating membranes. The sensor sensitivity as a function of the pressure load was also calculated by experimental tests. The results of the calibration of different capacitive pressure sensors are reported in this work, together with functional tests in a wind tunnel equipped with a curved wall plate on which a DBD plasma actuator was mounted to control the flow separation. The flow behavior was experimentally investigated by particle image velocimetry (PIV) measurements. Statistical and spectral analysis, applied to the output signals of the pressure sensor placed downstream of the profile leading edge, demonstrated that the sensor is able to discriminate different ionic wind velocity and turbulence conditions. The sensor sensitivity in the 0-100 Pa range was experimentally measured and it ranged between 0.0030 and 0.0046 pF Pa-1 for the best devices.

A new experimental procedure of outgassing rate measurement to obtain more precise deposition properties of materials

NASA Astrophysics Data System (ADS)

Miyazaki, Eiji; Shimazaki, Kazunori; Numata, Osamu; Waki, Miyuki; Yamanaka, Riyo; Kimoto, Yugo

2016-09-01

Outgassing rate measurement, or dynamic outgassing test, is used to obtain outgassing properties of materials, i.e., Total Mass Loss, "TML," and Collected Volatile Condensed Mass, "CVCM." The properties are used as input parameters for executing contamination analysis, e.g., calculating a prediction of deposition mass on a surface in a spacecraft caused by outgassed substances from contaminant sources onboard. It is likely that results obtained by such calculations are affected by the input parameters. Thus, it is important to get a sufficient experimental data set of outgassing rate measurements for extract good outgassing parameters of materials for calculation. As specified in the standard, ASTM E 1559, TML is measured by a QCM sensor kept at cryogenic temperature; CVCMs are measured at certain temperatures. In the present work, the authors propose a new experimental procedure to obtain more precise VCMs from one run of the current test time with the present equipment. That is, two of four CQCMs in the equipment control the temperature to cool step-by-step during the test run. It is expected that the deposition rate, that is sticking coefficient, with respect to temperature could be discovered. As a result, the sticking coefficient can be obtained directly between -50 and 50 degrees C with 5 degrees C step. It looks like the method could be used as an improved procedure for outgassing rate measurement. The present experiment also specified some issues of the new procedure. It will be considered in future work.

Guidance Of A Mobile Robot Using An Omnidirectional Vision Navigation System

NASA Astrophysics Data System (ADS)

Oh, Sung J.; Hall, Ernest L.

1987-01-01

Navigation and visual guidance are key topics in the design of a mobile robot. Omnidirectional vision using a very wide angle or fisheye lens provides a hemispherical view at a single instant that permits target location without mechanical scanning. The inherent image distortion with this view and the numerical errors accumulated from vision components can be corrected to provide accurate position determination for navigation and path control. The purpose of this paper is to present the experimental results and analyses of the imaging characteristics of the omnivision system including the design of robot-oriented experiments and the calibration of raw results. Errors less than one picture element on each axis were observed by testing the accuracy and repeatability of the experimental setup and the alignment between the robot and the sensor. Similar results were obtained for four different locations using corrected results of the linearity test between zenith angle and image location. Angular error of less than one degree and radial error of less than one Y picture element were observed at moderate relative speed. The significance of this work is that the experimental information and the test of coordinated operation of the equipment provide a greater understanding of the dynamic omnivision system characteristics, as well as insight into the evaluation and improvement of the prototype sensor for a mobile robot. Also, the calibration of the sensor is important, since the results provide a cornerstone for future developments. This sensor system is currently being developed for a robot lawn mower.

The efficacy of a HUBER exercise system mediated sensorimotor training protocol on proprioceptive system, lumbar movement control and quality of life in patients with chronic non-specific low back pain.

PubMed

Letafatkar, Amir; Nazarzadeh, Maryam; Hadadnezhad, Malihe; Farivar, Niloufar

2017-08-03

There is a relation between deficits of the proprioceptive system and movement control dysfunction in patients with chronic low back pain (LBP) but, the exact mechanism of this relation is unknown. Exercise therapy has been recognized as an effective method for low back pain treatment. In spite of this, it is not clear which of the various exercise therapy programs lead to better results. Therefore, the present analyze the efficacy of a HUBER study aims to exercise system mediated sensorimotor training protocol on proprioceptive system, lumbar movement control (LMC) and quality of life (QOL) in patients with chronic non-specific LBP. Quasi-experimental study. 53 patients with chronic non-specific LBP (mean age 37.55 ± 6.67 years,and Body Mass Index (BMI) 22.4 ± 3.33) were selected by using Roland-Morris Disability Questionnaire (RMQ) and were assigned into two experimental (N= 27) and control groups (N= 26) The experimental group underwent a five-week (10 sessions) Sensorimotor training by using the Human Body Equalizer (HUBER) spine force under the supervision of an investigator. The movement control battery tests, the HUBER machine testing option, goniometer and visual analogue scale used for movement control, neuromuscular coordination, proprioception and LBP assessment respectively. The assessments were completed in pre-test and after five weeks. The paired and sample T tests were used for data analysis in SPSS program version 18 (Significance level were set at a P value < 0.05). The HUBER system mediated sensorimotor training demonstrated significant improvement in the proprioceptive system, LMC and QOL (P= 0.001). Also There was a significant reduction in the pain scores of subjects with chronic non-specific LBP in the sensorimotor group (P= 0.001). In this study, only the short term effects of the sensorimotor training were examined. The results suggest that a sensorimotor training program causes significant improvement in patients with chronic non-specific LBP. Future research should be carried out with a larger sample size to examine the long term effects of the sensorimotor training program on treatment of patients with chronic non-specific LBP. Considering the efficacy of the sensorimotor training, it is recommended that this intervention should be applied to treatment of patients with chronic non-specific LBP in the future.

Capture of Hypervelocity Particles with Low-Density Aerogel

NASA Technical Reports Server (NTRS)

Hoerz, Friedrich; Cintala, Mark J.; Zolensky, Michael E.; Bernhard, Ronald B.; Haynes, Gerald; See, Thomas H.; Tsou, Peter; Brownlee, Donald E.

1998-01-01

Recent impact experiments conducted at Johnson Space Center supported a space-exposed flight instrument called the orbital debris collector (ODC) to see whether SiO2 acrogel performed adequately as a collector to capture cosmic dust particles and/or manmade debris, or whether additional development is needed. The first ODC was flown aboard the Mir for 18 months, while the second will be flown aboard a spacecraft (Stardust, to be launched in 1999) that will encounter the comet Wild 2 and return to Earth. Aerogels are highly porous materials that decelerate high-velocity particles without substantial melting or modifications to the particles' components; in other denser materials, these particles would melt or vaporize upon impact. The experimental data in this report must be considered somewhat qualitative because they are characterized by substantial, if not intolerable, scatter, possibly due to experimental difficulties in duplicating given sets of initial impact conditions. Therefore, this report is a chronological guide of the experimenters' attempts, difficulties, progress, and evaluations for future tests.

Fuel-rich, catalytic reaction experimental results

NASA Technical Reports Server (NTRS)

Rollbuhler, R. James

1991-01-01

Future aeropropulsion gas turbine combustion requirements call for operating at very high inlet temperatures, pressures, and large temperature rises. At the same time, the combustion process is to have minimum pollution effects on the environment. Aircraft gas turbine engines utilize liquid hydrocarbon fuels which are difficult to uniformly atomize and mix with combustion air. An approach for minimizing fuel related problems is to transform the liquid fuel into gaseous form prior to the completion of the combustion process. Experimentally obtained results are presented for vaporizing and partially oxidizing a liquid hydrocarbon fuel into burnable gaseous components. The presented experimental data show that 1200 to 1300 K reaction product gas, rich in hydrogen, carbon monoxide, and light-end hydrocarbons, is formed when flowing 0.3 to 0.6 fuel to air mixes through a catalyst reactor. The reaction temperatures are kept low enough that nitrogen oxides and carbon particles (soot) do not form. Results are reported for tests using different catalyst types and configurations, mass flowrates, input temperatures, and fuel to air ratios.

Precision experiments on mirror transitions at Notre Dame

NASA Astrophysics Data System (ADS)

Brodeur, Maxime; TwinSol Collaboration

2016-09-01

Thanks to extensive experimental efforts that led to a precise determination of important experimental quantities of superallowed pure Fermi transitions, we now have a very precise value for Vud that leads to a stringent test of the CKM matrix unitarity. Despite this achievement, measurements in other systems remain relevant as conflicting results could uncover unknown systematic effects or even new physics. One such system is the superallowed mixed transition, which can help refine theoretical corrections used for pure Fermi transitions and improve the accuracy of Vud. However, as a corrected Ft-value determination from these systems requires the more challenging determination of the Fermi Gamow-Teller mixing ratio, only five transitions, spreading from 19Ne to 37Ar, are currently fully characterized. To rectify the situation, an experimental program on precision experiment of mirror transitions that includes precision half-life measurements, and in the future, the determination of the Fermi Gamow-Teller mixing ratio, has started at the University of Notre Dame. This work is supported in part by the National Science Foundation.

Numerical and Experimental Study on Hydrodynamic Performance of A Novel Semi-Submersible Concept

NASA Astrophysics Data System (ADS)

Gao, Song; Tao, Long-bin; Kou, Yu-feng; Lu, Chao; Sun, Jiang-long

2018-04-01

Multiple Column Platform (MCP) semi-submersible is a newly proposed concept, which differs from the conventional semi-submersibles, featuring centre column and middle pontoon. It is paramount to ensure its structural reliability and safe operation at sea, and a rigorous investigation is conducted to examine the hydrodynamic and structural performance for the novel structure concept. In this paper, the numerical and experimental studies on the hydrodynamic performance of MCP are performed. Numerical simulations are conducted in both the frequency and time domains based on 3D potential theory. The numerical models are validated by experimental measurements obtained from extensive sets of model tests under both regular wave and irregular wave conditions. Moreover, a comparative study on MCP and two conventional semi-submersibles are carried out using numerical simulation. Specifically, the hydrodynamic characteristics, including hydrodynamic coefficients, natural periods and motion response amplitude operators (RAOs), mooring line tension are fully examined. The present study proves the feasibility of the novel MCP and demonstrates the potential possibility of optimization in the future study.

Ejected particle size measurement using Mie scattering in high explosive driven shockwave experiments

NASA Astrophysics Data System (ADS)

Monfared, S. K.; Buttler, W. T.; Frayer, D. K.; Grover, M.; LaLone, B. M.; Stevens, G. D.; Stone, J. B.; Turley, W. D.; Schauer, M. M.

2015-06-01

We report on the development of a diagnostic to provide constraints on the size of particles ejected from shocked metallic surfaces. The diagnostic is based on measurements of the intensity of laser light transmitted through a cloud of ejected particles as well as the angular distribution of scattered light, and the analysis of the resulting data is done using the Mie solution. We describe static experiments to test our experimental apparatus and present initial results of dynamic experiments on Sn targets. Improvements for future experiments are briefly discussed.

Geometrical and structural properties of an Aeroelastic Research Wing (ARW-2)

NASA Technical Reports Server (NTRS)

Sandford, Maynard C.; Seidel, David A.; Eckstrom, Clinton V.; Spain, Charles V.

1989-01-01

Transonic steady and unsteady pressure tests were conducted on a large elastic wing known as the DAST ARW-2 wing. The wing has a supercritical airfoil, an aspect ratio of 10.3, a leading edge sweepback angle of 28.8 deg and is equipped with two inboard and one outboard trailing edge control surfaces. The geometrical and structural characteristics are presented of this elastic wing, using a combination of measured and calculated data, to permit future analyst to compare the experimental surface pressure data with theoretical predictions.

Performance of Dental Ceramics

PubMed Central

Rekow, E.D.; Silva, N.R.F.A.; Coelho, P.G.; Zhang, Y.; Guess, P.; Thompson, V.P.

2011-01-01

The clinical success of modern dental ceramics depends on an array of factors, ranging from initial physical properties of the material itself, to the fabrication and clinical procedures that inevitably damage these brittle materials, and the oral environment. Understanding the influence of these factors on clinical performance has engaged the dental, ceramics, and engineering communities alike. The objective of this review is to first summarize clinical, experimental, and analytic results reported in the recent literature. Additionally, it seeks to address how this new information adds insight into predictive test procedures and reveals challenges for future improvements. PMID:21224408

Satellite Antenna Systems

NASA Technical Reports Server (NTRS)

1997-01-01

Through the Technology Affiliates Program at the Jet Propulsion Laboratory, the ACTS antenna system was transferred from experimental testing status to commercial development with KVH Industries, Inc. The ACTS design enables mobile satellite antennas to remain pointed at the satellite, regardless of the motion or vibration on which it is mounted. KVH's first product based on the ACTS design is a land-mobile satellite antenna system that will enable direct broadcast satellite television aboard moving trucks, recreational vehicles, trains, and buses. Future products could include use in broadcasting, emergency medical and military vehicles.

Review of NASA antiskid braking research

NASA Technical Reports Server (NTRS)

Tanner, J. A.

1982-01-01

NASA antiskid braking system research programs are reviewed. These programs include experimental studies of four antiskid systems on the Langley Landing Loads Track, flights tests with a DC-9 airplane, and computer simulation studies. Results from these research efforts include identification of factors contributing to degraded antiskid performance under adverse weather conditions, tire tread temperature measurements during antiskid braking on dry runway surfaces, and an assessment of the accuracy of various brake pressure-torque computer models. This information should lead to the development of better antiskid systems in the future.

Two-dimensional simulation of quantum reflection

NASA Astrophysics Data System (ADS)

Galiffi, Emanuele; Sünderhauf, Christoph; DeKieviet, Maarten; Wimberger, Sandro

2017-05-01

A propagation method for the scattering of a quantum wave packet from a potential surface is presented. It is used to model the quantum reflection of single atoms from a corrugated (metallic) surface. Our numerical procedure works well in two spatial dimensions requiring only reasonable amounts of memory and computing time. The effects of the surface corrugation on the reflectivity are investigated via simulations with a paradigm potential. These indicate that our approach should allow for future tests of realistic, effective potentials obtained from theory in a quantitative comparison to experimental data.

Development of a sensitive superconducting gravity gradiometer for geological and navigational applications

NASA Technical Reports Server (NTRS)

Paik, H. J.; Richard, J. P.

1986-01-01

A sensitive and stable gravity gradiometer would provide high resolution gravity measurements from space. The instrument could also provide precision tests of fundamental laws of physics and be applied to inertial guidance systems of the future. This report describes research on the superconducting gravity gradiometer program at the University of Maryland from July 1980 to July 1985. The report describes the theoretical and experimental work on a prototype superconducting gravity gradiometer. The design of an advanced three-axis superconducting gravity gradiometer is also discussed.

Validation of a three-dimensional viscous analysis of axisymmetric supersonic inlet flow fields

NASA Technical Reports Server (NTRS)

Benson, T. J.; Anderson, B. H.

1983-01-01

A three-dimensional viscous marching analysis for supersonic inlets was developed. To verify this analysis several benchmark axisymmetric test configurations were studied and are compared to experimental data. Detailed two-dimensional results for shock-boundary layer interactions are presented for flows with and without boundary layer bleed. Three dimensional calculations of a cone at angle of attack and a full inlet at attack are also discussed and evaluated. Results of the calculations demonstrate the code's ability to predict complex flow fields and establish guidelines for future calculations using similar codes.

Single Axis Attitude Control and DC Bus Regulation with Two Flywheels

NASA Technical Reports Server (NTRS)

Kascak, Peter E.; Jansen, Ralph H.; Kenny, Barbara; Dever, Timothy P.

2002-01-01

A computer simulation of a flywheel energy storage single axis attitude control system is described. The simulation models hardware which will be experimentally tested in the future. This hardware consists of two counter rotating flywheels mounted to an air table. The air table allows one axis of rotational motion. An inertia DC bus coordinator is set forth that allows the two control problems, bus regulation and attitude control, to be separated. Simulation results are presented with a previously derived flywheel bus regulator and a simple PID attitude controller.

Progress of Rugby Hohlraum Experiments on Omega

NASA Astrophysics Data System (ADS)

Philippe, Franck; Tassin, Veronique; Casner, Alexis; Gauthier, Pascal; Seytor, Patricia; Monteil, Marie-Christine; Park, Hye-Sook; Robey, Harry; Ross, Steven; Amendt, Peter; Girard, Frederic; Villette, Bruno; Reverdin, Charles; Loiseau, Pascal; Caillaud, Tony; Landoas, Olivier; Li, Chi Kang; Petrasso, Richard; Seguin, Fredrick; Rosenberg, Markus

2011-10-01

The rugby hohlraum concept is predicted to enable better coupling and higher gains in the indirect drive approach to ignition. A collaborative experimental program is currently pursued on OMEGA to test this concept in preparation for future megajoule-scale ignition designs. A direct comparison of gas-filled rugby hohlraums with classical cylinders was recently performed, showing a significant (up to ~40%) observed x-ray drive enhancement and neutron yields that are consistently higher in the rugby case. This work extends and confirms our previous findings in empty rugby hohlraums.

A review of nuclear thermal propulsion carbide fuel corrosion and key issues

NASA Technical Reports Server (NTRS)

Pelaccio, Dennis G.; El-Genk, Mohamed S.

1994-01-01

Corrosion (mass loss) of carbide nuclear fuels due to their exposure to hot hydrogen in nuclear thermal propulsion engine systems greatly impacts the performance, thrust-to-weight and life of such systems. This report provides an overview of key issues and processes associated with the corrosion of carbide materials. Additionally, past pertinent development reactor test observations, as well as related experimental work and analysis modeling efforts are reviewed. At the conclusion, recommendations are presented, which provide the foundation for future corrosion modeling and verification efforts.

Experimental Investigation of Soil and Atmospheric Conditions on the Momentum, Mass, and Thermal Boundary Layers Above the Land Atmosphere Interface

NASA Astrophysics Data System (ADS)

Trautz, A.; Smits, K. M.; Illangasekare, T. H.; Schulte, P.

2014-12-01

The purpose of this study is to investigate the impacts of soil conditions (i.e. soil type, saturation) and atmospheric forcings (i.e. velocity, temperature, relative humidity) on the momentum, mass, and temperature boundary layers. The atmospheric conditions tested represent those typically found in semi-arid and arid climates and the soil conditions simulate the three stages of evaporation. The data generated will help identify the importance of different soil conditions and atmospheric forcings with respect to land-atmospheric interactions which will have direct implications on future numerical studies investigating the effects of turbulent air flow on evaporation. The experimental datasets generated for this study were performed using a unique climate controlled closed-circuit wind tunnel/porous media facility located at the Center for Experimental Study of Subsurface Environmental Processes (CESEP) at the Colorado School of Mines. The test apparatus consisting of a 7.3 m long porous media tank and wind tunnel, were outfitted with a sensor network to carefully measure wind velocity, air and soil temperature, relative humidity, soil moisture, and soil air pressure. Boundary layer measurements were made between the heights of 2 and 500 mm above the soil tank under constant conditions (i.e. wind velocity, temperature, relative humidity). The soil conditions (e.g. soil type, soil moisture) were varied between datasets to analyze their impact on the boundary layers. Experimental results show that the momentum boundary layer is very sensitive to the applied atmospheric conditions and soil conditions to a much less extent. Increases in velocity above porous media leads to momentum boundary layer thinning and closely reflect classical flat plate theory. The mass and thermal boundary layers are directly dependent on both atmospheric and soil conditions. Air pressure within the soil is independent of atmospheric temperature and relative humidity - wind velocity and soil moisture effects were observed. This data provides important insight into future work of accurately modeling the exchange processes associated with evaporation under various turbulent atmospheric conditions.

Innovative experimental particle physics through technological advances: Past, present and future

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

Cheung, Harry W.K.; /Fermilab

This mini-course gives an introduction to the techniques used in experimental particle physics with an emphasis on the impact of technological advances. The basic detector types and particle accelerator facilities will be briefly covered with examples of their use and with comparisons. The mini-course ends with what can be expected in the near future from current technology advances. The mini-course is intended for graduate students and post-docs and as an introduction to experimental techniques for theorists.

Review on the EFDA programme on tungsten materials technology and science

NASA Astrophysics Data System (ADS)

Rieth, M.; Boutard, J. L.; Dudarev, S. L.; Ahlgren, T.; Antusch, S.; Baluc, N.; Barthe, M.-F.; Becquart, C. S.; Ciupinski, L.; Correia, J. B.; Domain, C.; Fikar, J.; Fortuna, E.; Fu, C.-C.; Gaganidze, E.; Galán, T. L.; García-Rosales, C.; Gludovatz, B.; Greuner, H.; Heinola, K.; Holstein, N.; Juslin, N.; Koch, F.; Krauss, W.; Kurzydlowski, K. J.; Linke, J.; Linsmeier, Ch.; Luzginova, N.; Maier, H.; Martínez, M. S.; Missiaen, J. M.; Muhammed, M.; Muñoz, A.; Muzyk, M.; Nordlund, K.; Nguyen-Manh, D.; Norajitra, P.; Opschoor, J.; Pintsuk, G.; Pippan, R.; Ritz, G.; Romaner, L.; Rupp, D.; Schäublin, R.; Schlosser, J.; Uytdenhouwen, I.; van der Laan, J. G.; Veleva, L.; Ventelon, L.; Wahlberg, S.; Willaime, F.; Wurster, S.; Yar, M. A.

2011-10-01

All the recent DEMO design studies for helium cooled divertors utilize tungsten materials and alloys, mainly due to their high temperature strength, good thermal conductivity, low erosion, and comparably low activation under neutron irradiation. The long-term objective of the EFDA fusion materials programme is to develop structural as well as armor materials in combination with the necessary production and fabrication technologies for future divertor concepts. The programmatic roadmap is structured into four engineering research lines which comprise fabrication process development, structural material development, armor material optimization, and irradiation performance testing, which are complemented by a fundamental research programme on "Materials Science and Modeling". This paper presents the current research status of the EFDA experimental and testing investigations, and gives a detailed overview of the latest results on fabrication, joining, high heat flux testing, plasticity, modeling, and validation experiments.

Brush Seal Performance and Durability Issues Based on T-700 Engine Test Results

NASA Technical Reports Server (NTRS)

Hendricks, R. C.

1994-01-01

The integrity and performance of brush seals have been established. Severe bench and engine tests have shown high initial wear or run-in rates, material smearing at the interface, and bristle and rub-runner wear, but the brush seals did not fail. Short-duration (46 hr) experimental T-700 engine testing of the compressor discharge seal established over 1-percent engine performance gain (brush versus labyrinth). Long-term gains were established only as leakage comparisons, with the brush at least 20 percent better at controlling leakage. Long-term materials issues, such as wear and ultimately seal life, remain to be resolved. Future needs are cited for materials and analysis tools that account for heat generation, thermomechanical behavior, and tribological pairing to enable original equipment manufacturers to design high-temperature, high-surface-speed seals with confidence.

Oxygen Mass Transport in Stented Coronary Arteries.

PubMed

Murphy, Eoin A; Dunne, Adrian S; Martin, David M; Boyle, Fergal J

2016-02-01

Oxygen deficiency, known as hypoxia, in arterial walls has been linked to increased intimal hyperplasia, which is the main adverse biological process causing in-stent restenosis. Stent implantation has significant effects on the oxygen transport into the arterial wall. Elucidating these effects is critical to optimizing future stent designs. In this study the most advanced oxygen transport model developed to date was assessed in two test cases and used to compare three coronary stent designs. Additionally, the predicted results from four simplified blood oxygen transport models are compared in the two test cases. The advanced model showed good agreement with experimental measurements within the mass-transfer boundary layer and at the luminal surface; however, more work is needed in predicting the oxygen transport within the arterial wall. Simplifying the oxygen transport model within the blood flow produces significant errors in predicting the oxygen transport in arteries. This study can be used as a guide for all future numerical studies in this area and the advanced model could provide a powerful tool in aiding design of stents and other cardiovascular devices.

Neutron-antineutron oscillations: Theoretical status and experimental prospects

DOE PAGES

Phillips, D. G.; Snow, W. M.; Babu, K.; ...

2016-02-01

This paper summarizes the relevant theoretical developments, outlines some ideas to improve experimental searches for free neutron-antineutron oscillations, and suggests avenues for future improvement in the experimental sensitivity.

Engineering platform and experimental protocol for design and evaluation of a neurally-controlled powered transfemoral prosthesis.

PubMed

Zhang, Fan; Liu, Ming; Harper, Stephen; Lee, Michael; Huang, He

2014-07-22

To enable intuitive operation of powered artificial legs, an interface between user and prosthesis that can recognize the user's movement intent is desired. A novel neural-machine interface (NMI) based on neuromuscular-mechanical fusion developed in our previous study has demonstrated a great potential to accurately identify the intended movement of transfemoral amputees. However, this interface has not yet been integrated with a powered prosthetic leg for true neural control. This study aimed to report (1) a flexible platform to implement and optimize neural control of powered lower limb prosthesis and (2) an experimental setup and protocol to evaluate neural prosthesis control on patients with lower limb amputations. First a platform based on a PC and a visual programming environment were developed to implement the prosthesis control algorithms, including NMI training algorithm, NMI online testing algorithm, and intrinsic control algorithm. To demonstrate the function of this platform, in this study the NMI based on neuromuscular-mechanical fusion was hierarchically integrated with intrinsic control of a prototypical transfemoral prosthesis. One patient with a unilateral transfemoral amputation was recruited to evaluate our implemented neural controller when performing activities, such as standing, level-ground walking, ramp ascent, and ramp descent continuously in the laboratory. A novel experimental setup and protocol were developed in order to test the new prosthesis control safely and efficiently. The presented proof-of-concept platform and experimental setup and protocol could aid the future development and application of neurally-controlled powered artificial legs.

The Future of Hadrons: The Nexus of Subatomic Physics

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

Quigg, Chris

2011-09-01

The author offers brief observations on matters discussed at the XIV International Conference on Hadron Spectroscopy and explore prospects for hadron physics. Quantum chromodynamics (QCD) has been validated as a new law of nature. It is internally consistent up to very high energies, and so could be a complete theory of the strong interactions. Whether QCD is the final answer for the strong interactions is a subject for continuing experimental tests, which are being extended in experimentation at the Large Hadron Collider. Beyond the comparison of perturbative calculations with experiment, it remains critically important to test the confinement hypothesis bymore » searching for free quarks, or for signatures of unconfined color. Sensitive negative searches for quarks continue to be interesting, and the definitive observation of free quarks would be revolutionary. Breakdowns of factorization would compromise the utility of perturbative QCD. Other discoveries that would require small or large revisions to QCD include the observation of new kinds of colored matter beyond quarks and gluons, the discovery that quarks are composite, or evidence that SU(3){sub c} gauge symmetry is the vestige of a larger, spontaneously broken, color symmetry. While probing our underlying theory for weakness or new openings, we have plenty to do to apply QCD to myriad experimental settings, to learn its implications for matter under unusual conditions, and to become more adept at calculating its consequences. New experimental tools provide the means for progress on a very broad front.« less

Computational/experimental studies of isolated, single component droplet combustion

NASA Technical Reports Server (NTRS)

Dryer, Frederick L.

1993-01-01

Isolated droplet combustion processes have been the subject of extensive experimental and theoretical investigations for nearly 40 years. The gross features of droplet burning are qualitatively embodied by simple theories and are relatively well understood. However, there remain significant aspects of droplet burning, particularly its dynamics, for which additional basic knowledge is needed for thorough interpretations and quantitative explanations of transient phenomena. Spherically-symmetric droplet combustion, which can only be approximated under conditions of both low Reynolds and Grashof numbers, represents the simplest geometrical configuration in which to study the coupled chemical/transport processes inherent within non-premixed flames. The research summarized here, concerns recent results on isolated, single component, droplet combustion under microgravity conditions, a program pursued jointly with F.A. Williams of the University of California, San Diego. The overall program involves developing and applying experimental methods to study the burning of isolated, single component droplets, in various atmospheres, primarily at atmospheric pressure and below, in both drop towers and aboard space-based platforms such as the Space Shuttle or Space Station. Both computational methods and asymptotic methods, the latter pursued mainly at UCSD, are used in developing the experimental test matrix, in analyzing results, and for extending theoretical understanding. Methanol, and the normal alkanes, n-heptane, and n-decane, have been selected as test fuels to study time-dependent droplet burning phenomena. The following sections summarizes the Princeton efforts on this program, describe work in progress, and briefly delineate future research directions.

An experimental test of an extended discretion approach for high school biology laboratory investigations

NASA Astrophysics Data System (ADS)

Leonard, William H.; Cavana, Gordon R.; Lowery, Lawrence F.

Discretion-the exercise of independent judgment-was observed to be lacking in most commercially available laboratory investigations for high school biology. An Extended Discretion (ED) laboratory approach was developed and tested experimentally against the BSCS Green Version laboratory program, using ten classes of 10th-grade biology in a suburban California high school. Five teachers were each assigned one experimental and one control group. The primary differences between the two approaches were that the BSCS was more prescriptive and directive than the ED approach and the ED approach increased discretionary demands upon the student over the school year. A treatment verification procedure showed statistically significant differences between the two approaches. The hypothesis under test was that when high school biology students are taught laboratory concepts under comparatively high discretionary demands, they would perform as well as or better than a similar group of students taught with BSCS Green Version investigations. A second hypothesis was that teachers would prefer to use the ED approach over the BSCS approach for their future classes. A t analysis between experimental and control groups for each teacher was employed. There were significant differences in favor of the ED group on laboratory report scores for three teachers and no differences for two teachers. There were significant differences in favor of the ED group on laboratory concepts quiz scores for three teachers, no differences for one teacher, and significant differences in favor of the BSCS group for only one teacher. A t analysis of teacher evaluation of the two approaches showed a significant teacher preference overall for the ED approach. Both experimental hypotheses were accepted. The ED approach was observed to be difficult for students at first, but it was found to be a workable and productive means of teaching laboratory concepts in biology which also required extensive use of individual student discretion.

Risk as feelings in the effect of patient outcomes on physicians' future treatment decisions: a randomized trial and manipulation validation.

PubMed

Hemmerich, Joshua A; Elstein, Arthur S; Schwarze, Margaret L; Moliski, Elizabeth Ghini; Dale, William

2012-07-01

The present study tested predictions derived from the Risk as Feelings hypothesis about the effects of prior patients' negative treatment outcomes on physicians' subsequent treatment decisions. Two experiments at The University of Chicago, U.S.A., utilized a computer simulation of an abdominal aortic aneurysm (AAA) patient with enhanced realism to present participants with one of three experimental conditions: AAA rupture causing a watchful waiting death (WWD), perioperative death (PD), or a successful operation (SO), as well as the statistical treatment guidelines for AAA. Experiment 1 tested effects of these simulated outcomes on (n = 76) laboratory participants' (university student sample) self-reported emotions, and their ratings of valence and arousal of the AAA rupture simulation and other emotion-inducing picture stimuli. Experiment 2 tested two hypotheses: 1) that experiencing a patient WWD in the practice trial's experimental condition would lead physicians to choose surgery earlier, and 2) experiencing a patient PD would lead physicians to choose surgery later with the next patient. Experiment 2 presented (n = 132) physicians (surgeons and geriatricians) with the same experimental manipulation and a second simulated AAA patient. Physicians then chose to either go to surgery or continue watchful waiting. The results of Experiment 1 demonstrated that the WWD experimental condition significantly increased anxiety, and was rated similarly to other negative and arousing pictures. The results of Experiment 2 demonstrated that, after controlling for demographics, baseline anxiety, intolerance for uncertainty, risk attitudes, and the influence of simulation characteristics, the WWD experimental condition significantly expedited decisions to choose surgery for the next patient. The results support the Risk as Feelings hypothesis on physicians' treatment decisions in a realistic AAA patient computer simulation. Bad outcomes affected emotions and decisions, even with statistical AAA rupture risk guidance present. These results suggest that bad patient outcomes cause physicians to experience anxiety and regret that influences their subsequent treatment decision-making for the next patient. Copyright © 2012 Elsevier Ltd. All rights reserved.

National Transonic Facility Wall Pressure Calibration Using Modern Design of Experiments (Invited)

NASA Technical Reports Server (NTRS)

Underwood, Pamela J.; Everhart, Joel L.; DeLoach, Richard

2001-01-01

The Modern Design of Experiments (MDOE) has been applied to wind tunnel testing at NASA Langley Research Center for several years. At Langley, MDOE has proven to be a useful and robust approach to aerodynamic testing that yields significant reductions in the cost and duration of experiments while still providing for the highest quality research results. This paper extends its application to include empty tunnel wall pressure calibrations. These calibrations are performed in support of wall interference corrections. This paper will present the experimental objectives, and the theoretical design process. To validate the tunnel-empty-calibration experiment design, preliminary response surface models calculated from previously acquired data are also presented. Finally, lessons learned and future wall interference applications of MDOE are discussed.

RESULTS OF INITIAL AMMONIA OXIDATION TESTING

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

Nash, C.; Fowley, M.

This memo presents an experimental survey of aqueous phase chemical processes to remove aqueous ammonia from waste process streams. Ammonia is generated in both the current Hanford waste flowsheet and in future waste processing. Much ammonia will be generated in the Low Activity Waste (LAW) melters.i Testing with simulants in glass melters at Catholic University has demonstrated the significant ammonia production.ii The primary reaction there is the reducing action of sugar on nitrate in the melter cold cap. Ammonia has been found to be a problem in secondary waste stabilization. Ammonia vapors are noxious and destruction of ammonia could reducemore » hazards to waste treatment process personnel. It is easily evolved especially when ammonia-bearing solutions are adjusted to high pH.« less

Characterization of Thin Film Polymers Through Dynamic Mechanical Analysis and Permeation

NASA Technical Reports Server (NTRS)

Herring, Helen

2003-01-01

Thin polymer films are being considered, as candidate materials to augment the permeation resistance of cryogenic hydrogen fuel tanks such as would be required for future reusable launch vehicles. To evaluate performance of candidate films after environmental exposure, an experimental study was performed to measure the thermal/mechanical and permeation performance of six, commercial-grade materials. Dynamic storage modulus, as measured by Dynamic Mechanical Analysis, was found over a range of temperatures. Permeability, as measured by helium gas diffusion, was found at room temperature. Test data was correlated with respect to film type and pre-test exposure to moisture, elevated temperature, and cryogenic temperature. Results indicated that the six films were comparable in performance and their resistance to environmental degradation.

Development of a Reactor for the Extraction of Oxygen and Volatiles From Lunar Regolith

NASA Technical Reports Server (NTRS)

Kleinhenz, Julie; Yuan, Zengguang; Sacksteder, Kurt; Caruso, John

2009-01-01

The RESOLVE (Regolith and Environment Science, Oxygen and Lunar Volatiles Extraction) Project, aims to extract and quantify useful resources from lunar soil. The reactor developed for RESOLVE is a dual purpose system, designed to evolve both water, at 150 C and up to 80 psig, and oxygen, using hydrogen reduction at 900 C. A variety of laboratory tests were performed to verify its operation and to explore the properties of the analog site soil. The results were also applied to modeling efforts which are being used to estimate the apparent thermal properties of the soil. The experimental and numerical results, along with the analog site tests, will be used to evolve and optimize future reactor designs.

Low Velocity Earth-Penetration Test and Analysis

NASA Technical Reports Server (NTRS)

Fasanella, Edwin L.; Jones, Yvonne; Knight, Norman F., Jr.; Kellas, Sotiris

2001-01-01

Modeling and simulation of structural impacts into soil continue to challenge analysts to develop accurate material models and detailed analytical simulations to predict the soil penetration event. This paper discusses finite element modeling of a series of penetrometer drop tests into soft clay. Parametric studies are performed with penetrometers of varying diameters, masses, and impact speeds to a maximum of 45 m/s. Parameters influencing the simulation such as the contact penalty factor and the material model representing the soil are also studied. An empirical relationship between key parameters is developed and is shown to correlate experimental and analytical results quite well. The results provide preliminary design guidelines for Earth impact that may be useful for future space exploration sample return missions.

Test-specific control conditions for functional analyses.

PubMed

Fahmie, Tara A; Iwata, Brian A; Querim, Angie C; Harper, Jill M

2013-01-01

Most functional analyses of problem behavior include a common condition (play or noncontingent reinforcement) as a control for both positive and negative reinforcement. However, test-specific conditions that control for each potential source of reinforcement may be beneficial occasionally. We compared responding during alone, ignore, play, and differential reinforcement of other behavior (DRO) control conditions for individuals whose problem behavior was maintained by positive or negative reinforcement. Results showed that all of the conditions were effective controls for problem behavior maintained by positive reinforcement; however, the DRO condition was consistently ineffective as a control for problem behavior maintained by negative reinforcement. Implications for the design of functional analyses and future research are discussed. © Society for the Experimental Analysis of Behavior.

Quantum light in coupled interferometers for quantum gravity tests.

PubMed

Ruo Berchera, I; Degiovanni, I P; Olivares, S; Genovese, M

2013-05-24

In recent years quantum correlations have received a lot of attention as a key ingredient in advanced quantum metrology protocols. In this Letter we show that they provide even larger advantages when considering multiple-interferometer setups. In particular, we demonstrate that the use of quantum correlated light beams in coupled interferometers leads to substantial advantages with respect to classical light, up to a noise-free scenario for the ideal lossless case. On the one hand, our results prompt the possibility of testing quantum gravity in experimental configurations affordable in current quantum optics laboratories and strongly improve the precision in "larger size experiments" such as the Fermilab holometer; on the other hand, they pave the way for future applications to high precision measurements and quantum metrology.

Preliminary design of mesoscale turbocompressor and rotordynamics tests of rotor bearing system

NASA Astrophysics Data System (ADS)

Hossain, Md Saddam

2011-12-01

A mesoscale turbocompressor spinning above 500,000 RPM is evolutionary technology for micro turbochargers, turbo blowers, turbo compressors, micro-gas turbines, auxiliary power units, etc for automotive, aerospace, and fuel cell industries. Objectives of this work are: (1) to evaluate different air foil bearings designed for the intended applications, and (2) to design & perform CFD analysis of a micro-compressor. CFD analysis of shrouded 3-D micro compressor was conducted using Ansys Bladegen as blade generation tool, ICEM CFD as mesh generation tool, and CFX as main solver for different design and off design cases and also for different number of blades. Comprehensive experimental facilities for testing the turbocompressor system have been also designed and proposed for future work.

Meaning-making intervention during breast or colorectal cancer treatment improves self-esteem, optimism, and self-efficacy.

PubMed

Lee, Virginia; Robin Cohen, S; Edgar, Linda; Laizner, Andrea M; Gagnon, Anita J

2006-06-01

Existential issues often accompany a diagnosis of cancer and remain one aspect of psychosocial oncology care for which there is a need for focused, empirically tested interventions. This study examined the efficacy of a novel psychological intervention specifically designed to address existential issues through the use of meaning-making coping strategies on psychological adjustment to cancer. Eighty-two breast or colorectal cancer patients were randomly chosen to receive routine care (control group) or up to four sessions that explored the meaning of the emotional responses and cognitive appraisals of each individual's cancer experience within the context of past life events and future goals (experimental group). This paper reports the results from 74 patients who completed and returned pre- and post-test measures for self-esteem, optimism, and self-efficacy. After controlling for baseline scores, the experimental group participants demonstrated significantly higher levels of self-esteem, optimism, and self-efficacy compared to the control group. The results are discussed in light of the theoretical and clinical implications of meaning-making coping in the context of stress and illness.

The Role of Formal Experiment Design in Hypersonic Flight System Technology Development

NASA Technical Reports Server (NTRS)

McClinton, Charles R.; Ferlemann, Shelly M.; Rock, Ken E.; Ferlemann, Paul G.

2002-01-01

Hypersonic airbreathing engine (scramjet) powered vehicles are being considered to replace conventional rocket-powered launch systems. Effective utilization of scramjet engines requires careful integration with the air vehicle. This integration synergistically combines aerodynamic forces with propulsive cycle functions of the engine. Due to the highly integrated nature of the hypersonic vehicle design problem, the large flight envelope, and the large number of design variables, the use of a statistical design approach in design is effective. Modern Design-of-Experiments (MDOE) has been used throughout the Hyper-X program, for both systems analysis and experimental testing. Application of MDOE fall into four categories: (1) experimental testing; (2) studies of unit phenomena; (3) refining engine design; and (4) full vehicle system optimization. The MDOE process also provides analytical models, which are also used to document lessons learned, supplement low-level design tools, and accelerate future studies. This paper will discuss the design considerations for scramjet-powered vehicles, specifics of MDOE utilized for Hyper-X, and present highlights from the use of these MDOE methods within the Hyper-X Program.

Verification of Electromagnetic Physics Models for Parallel Computing Architectures in the GeantV Project

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

Amadio, G.; et al.

An intensive R&D and programming effort is required to accomplish new challenges posed by future experimental high-energy particle physics (HEP) programs. The GeantV project aims to narrow the gap between the performance of the existing HEP detector simulation software and the ideal performance achievable, exploiting latest advances in computing technology. The project has developed a particle detector simulation prototype capable of transporting in parallel particles in complex geometries exploiting instruction level microparallelism (SIMD and SIMT), task-level parallelism (multithreading) and high-level parallelism (MPI), leveraging both the multi-core and the many-core opportunities. We present preliminary verification results concerning the electromagnetic (EM) physicsmore » models developed for parallel computing architectures within the GeantV project. In order to exploit the potential of vectorization and accelerators and to make the physics model effectively parallelizable, advanced sampling techniques have been implemented and tested. In this paper we introduce a set of automated statistical tests in order to verify the vectorized models by checking their consistency with the corresponding Geant4 models and to validate them against experimental data.« less

Experimental and Analytical Performance of a Dual Brayton Power Conversion System

NASA Technical Reports Server (NTRS)

Lavelle, Thomas A.; Hervol, David S.; Briggs, Maxwell; Owen, A. Karl

2009-01-01

The interactions between two closed Brayton cycle (CBC) power conversion units (PCU) which share a common gas inventory and heat source have been studied experimentally using the Dual Brayton Power Conversion System (DBPCS) and analytically using the Closed- Cycle System Simulation (CCSS) computer code. Selected operating modes include steady-state operation at equal and unequal shaft speeds and various start-up scenarios. Equal shaft speed steady-state tests were conducted for heater exit temperatures of 840 to 950 K and speeds of 50 to 90 krpm, providing a system performance map. Unequal shaft speed steady-state testing over the same operating conditions shows that the power produced by each Brayton is sensitive to the operating conditions of the other due to redistribution of gas inventory. Startup scenarios show that starting the engines one at a time can dramatically reduce the required motoring energy. Although the DBPCS is not considered a flight-like system, these insights, as well as the operational experience gained from operating and modeling this system provide valuable information for the future development of Brayton systems.

Lessons learned on the Ground Test Accelerator control system

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

Kozubal, A.J.; Weiss, R.E.

1994-09-01

When we initiated the control system design for the Ground Test Accelerator (GTA), we envisioned a system that would be flexible enough to handle the changing requirements of an experimental project. This control system would use a developers` toolkit to reduce the cost and time to develop applications for GTA, and through the use of open standards, the system would accommodate unforeseen requirements as they arose. Furthermore, we would attempt to demonstrate on GTA a level of automation far beyond that achieved by existing accelerator control systems. How well did we achieve these goals? What were the stumbling blocks tomore » deploying the control system, and what assumptions did we make about requirements that turned out to be incorrect? In this paper we look at the process of developing a control system that evolved into what is now the ``Experimental Physics and Industrial Control System`` (EPICS). Also, we assess the impact of this system on the GTA project, as well as the impact of GTA on EPICS. The lessons learned on GTA will be valuable for future projects.« less

Quantum internet: the certifiable road ahead

NASA Astrophysics Data System (ADS)

Elkouss, David; Lipinska, Victoria; Goodenough, Kenneth; Rozpedek, Filip; Kalb, Norbert; van Dam, Suzanne; Le Phuc, Thinh; Murta, Glaucia; Humphreys, Peter; Taminiau, Tim; Hanson, Ronald; Wehner, Stephanie

A future quantum internet enables quantum communication between any two points on earth in order to solve problems which are provably impossible using classical communication. The most well-known application of quantum communication is quantum key distribution, which allows two users to establish an encryption key. However, many other applications are known ranging from protocols for clock synchronization, extending the baselines of telescopes to exponential savings in communication. Due to recent technological progress, we are now on the verge of seeing the first small-scale quantum communication networks being realized. Here, we present a roadmap towards the ultimate form of a quantum internet. Specifically, we identify stages of development that are distinguished by an ever increasing amount of functionality. Each stage supports a certain class of quantum protocols and is interesting in its own right. What's more, we propose a series of simple tests to certify that an experimental implementation has achieved a certain stage. Jointly, the stages and the certification tests will allow us to track and benchmark experimental progress in the years to come. This work is supported by STW, NWO VIDI and ERC Starting Grant.

Single Axis Flywheel IPACS @1300W, 0.8 N-m

NASA Technical Reports Server (NTRS)

Jansen, Ralph; Kenny, Barbara; Kascak, Peter; Dever, Tim; Santiago, Walter

2005-01-01

NASA Glenn Research Center is developing flywheels for space systems. A single axis laboratory version of an integrated power and attitude control (IPACs) system has been experimentally demonstrated. This is a significant step on the road to a flight qualified three axes IPACS system. The presentation outlines the flywheel development process at NASA GRC, the experimental hardware and approach, the IPACS control algorithm that was formulated and the results of the test program and then proposes a direction for future work. GRC has made progress on flywheel module design in terms of specific energy density and capability through a design and test program resulting in three flywheel module designs. Two of the flywheels are used in the 1D-IPACS experiment with loads and power sources to simulate a satellite power system. The system response is measured in three power modes: charge, discharge, and charge reduction while simultaneously producing a net output torque which could be used for attitude control. Finally, recommendations are made for steps that should be taken to evolve from this laboratory demonstration to a flight like system.

Extended-Range Forecasts at Climate Prediction Center: Current Status and Future Plans

NASA Astrophysics Data System (ADS)

Kumar, A.

2016-12-01

Motivated by a user need to provide forecast information on extended-range time-scales (i.e., weeks 2-4), in recent years Climate Prediction Center (CPC) has made considerable efforts towards developing and testing the feasibility for developing the required forecasts. The forecasts targeting this particular time-scale face a unique challenge in that while the forecast skill due to atmospheric initial conditions is small (because of rapid decay in the memory associated with the atmospheric initial conditions), short time averages for which forecasts are made do not benefit from skill associated with anomalous boundary conditions either. Despite these challenges, CPC has embarked on providing an experimental outlook for weeks 3-4 average. The talk will summarize the current status of CPC's current suite of extended-range forecast products, and further, will discuss some future plans.

Contributions of axionlike particles to lepton dipole moments

DOE PAGES

Marciano, W. J.; Masiero, A.; Paradisi, P.; ...

2016-12-30

We examined contributions of a spin-0 axionlike particle (ALP) to lepton dipole moments, g - 2 and EDMs. Barr-Zee and light-by-light loop effects from a light pseudoscalar ALP are found to be capable of resolving the longstanding muon g - 2 discrepancy at the expense of relatively large ALP - γ γ couplings. We also discussed the compatibility of such large couplings with direct experimental constraints and perturbative unitarity bounds. Future tests of such a scenario are described. For C P -violating ALP couplings, the electron EDM is found to probe much smaller, theoretically more easily accommodated ALP interactions. Wemore » advocate future planned improvements in electron EDM searches as a way to not only significantly constrain ALP parameters, but also potentially unveil a new source of C P violation which could have far-reaching ramifications.« less

Time takes space: selective effects of multitasking on concurrent spatial processing.

PubMed

Mäntylä, Timo; Coni, Valentina; Kubik, Veit; Todorov, Ivo; Del Missier, Fabio

2017-08-01

Many everyday activities require coordination and monitoring of complex relations of future goals and deadlines. Cognitive offloading may provide an efficient strategy for reducing control demands by representing future goals and deadlines as a pattern of spatial relations. We tested the hypothesis that multiple-task monitoring involves time-to-space transformational processes, and that these spatial effects are selective with greater demands on coordinate (metric) than categorical (nonmetric) spatial relation processing. Participants completed a multitasking session in which they monitored four series of deadlines, running on different time scales, while making concurrent coordinate or categorical spatial judgments. We expected and found that multitasking taxes concurrent coordinate, but not categorical, spatial processing. Furthermore, males showed a better multitasking performance than females. These findings provide novel experimental evidence for the hypothesis that efficient multitasking involves metric relational processing.

Rotating rake design for unique measurement of fan-generated spinning acoustic modes

NASA Technical Reports Server (NTRS)

Konno, Kevin E.; Hausmann, Clifford R.

1993-01-01

In light of the current emphasis on noise reduction in subsonic aircraft design, NASA has been actively studying the source of and propagation of noise generated by subsonic fan engines. NASA/LeRC has developed and tested a unique method of accurately measuring these spinning acoustic modes generated by an experimental fan. This mode measuring method is based on the use of a rotating microphone rake. Testing was conducted in the 9 x 15 Low-speed Wind Tunnel. The rotating rake was tested with the Advanced Ducted Propeller (ADP) model. This memorandum discusses the design and performance of the motor/drive system for the fan-synchronized rotating acoustic rake. This novel motor/drive design approach is now being adapted for additional acoustic mode studies in new test rigs as baseline data for the future design of active noise control for subsonic fan engines. Included in this memorandum are the research requirements, motor/drive specifications, test performance results, and a description of the controls and software involved.

Strain controlled cyclic tests on miniaturized specimens

NASA Astrophysics Data System (ADS)

Procházka, R.; Džugan, J.

2017-02-01

The paper is dealing with strain controlled cyclic tests using a non-contact strain measurement based on digital image correlation techniques on proportional sizes of conventional specimens. The cyclic behaviour of 34CrNiMo6 high-strength steel was investigated on miniaturized round specimens with diameter of 2mm that were compared with specimens in accordance with ASTM E606 standards. The cycle asymmetry coefficient was R= -1. This application is intended to be used for life time assessment of in service components in future work which enables to carried out a group of mechanical tests from a limited amount of the experimental material. The attention was paid to confirm the suitability of the proposed size miniaturization geometry, testing set up and procedure. The test results obtained enabled to construct Manson-Coffin curves and assess fatigue parameters. The purpose of this study is to present differences between cyclic curves and cyclic parameters which have been evaluated based on conventional and miniaturized specimens.

Numerical modeling of a 2K J-T heat exchanger used in Fermilab Vertical Test Stand VTS-1

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

Gupta, Prabhat Kumar; Rabehl, Roger

2014-07-01

Fermilab Vertical Test Stand-1 (VTS-1) is in operation since 2007 for testing the superconducting RF cavities at 2 K. This test stand has single layer coiled finned tubes heat exchanger before J-T valve. A finite difference based thermal model has been developed in Engineering Equation Solver (EES) to study its thermal performance during filling and refilling to maintain the constant liquid level of test stand. The model is also useful to predict its performance under other various operating conditions and will be useful to design the similar kind of heat exchanger for future needs. Present paper discusses the different operationalmore » modes of this heat exchanger and its thermal characteristics under these operational modes. Results of this model have also been compared with the experimental data gathered from the VTS-1 heat exchanger and they are in good agreement with the present model.« less

Post Flight Analysis Of SHEFEX I: Shock Tunnel Testing And Related CFD Analysis

NASA Astrophysics Data System (ADS)

Schramm, Jan Martinez; Barth, Tarik; Wagner, Alexander; Hannemann, Klaus

2011-05-01

The SHarp Edge Flight EXperiment (SHEFEX) program of the German Aerospace Center (DLR) is primarily focused on the investigation of the potential to utilise improved shapes for space vehicles by considering sharp edges and facetted surfaces. One goal is to set up a sky based test facility to gain knowledge of the physics of hypersonic flow, complemented by numerical analysis and ground based testing. Further, the series of SHEFEX flight experiments is an excellent test bed for new technological concepts and flight instrumentation, and it is a source of motivation for young scientist and engineers providing an excellent school for future space-program engineers and managers. After the successful first SHEFEX flight in October 2005, a second flight is scheduled for September 2011 and additional flights are planned for 2015 ff. With the SHEFEX-I flight and the subsequent numerical and experimental post flight analysis, DLR could for the first time close the loop between the three major disciplines of aerothermodynamic research namely CFD, ground based testing and flight.

ASTAR Flight Test: Overview and Spacing Results

NASA Technical Reports Server (NTRS)

Roper, Roy D.; Koch, Michael R.

2016-01-01

The purpose of the NASA Langley Airborne Spacing for Terminal Arrival Routes (ASTAR) research aboard the Boeing ecoDemonstrator aircraft was to demonstrate the use of NASA's ASTAR algorithm using contemporary tools of the Federal Aviation Administration's Next Generation Air Transportation System (NEXTGEN). EcoDemonstrator is a Boeing test program which utilizes advanced experimental equipment to accelerate the science of aerospace and environmentally friendly technologies. The ASTAR Flight Test provided a proof-of-concept flight demonstration that exercised an algorithmic-based application in an actual aircraft. The test aircraft conducted Interval Management operations to provide time-based spacing off a target aircraft in non-simulator wind conditions. Work was conducted as a joint effort between NASA and Boeing to integrate ASTAR in a Boeing supplied B787 test aircraft while using a T-38 aircraft as the target. This demonstration was also used to identify operational risks to future flight trials for the NASA Air Traffic Management Technology Demonstration expected in 2017.

Evaluation of a hepatitis B lay health worker intervention for Chinese Americans and Canadians.

PubMed

Taylor, Vicky M; Hislop, T Gregory; Tu, Shin-Ping; Teh, Chong; Acorda, Elizabeth; Yip, Mei-Po; Woodall, Erica; Yasui, Yutaka

2009-06-01

Hepatitis B testing is recommended for immigrants from countries where hepatitis B infection is endemic. However, only about one-half of Chinese in North America have received hepatitis B testing. We conducted a randomized controlled trial to evaluate the effectiveness of a hepatitis B lay health worker intervention for Chinese Americans/Canadians. Four hundred and sixty individuals who had never been tested for hepatitis B were identified from community-based surveys of Chinese conducted in Seattle, Washington, and Vancouver, British Columbia. These individuals were randomly assigned to receive a hepatitis B lay health worker intervention or a direct mailing of physical activity educational materials. Follow-up surveys were completed 6 months after randomization. Self-reported hepatitis B testing was verified through medical records review. A total of 319 individuals responded to the follow-up survey (69% response rate). Medical records data verified hepatitis B testing since randomization for 9 (6%) of the 142 experimental group participants and 3 (2%) of the 177 control group participants (P = 0.04). At follow-up, a higher proportion of individuals in the experimental arm than individuals in the control arm knew that hepatitis B can be spread by razors (P < 0.001) and during sexual intercourse (P = 0.07). Our findings suggest that lay health worker interventions can impact hepatitis B-related knowledge. However, our hepatitis B lay health worker intervention had a very limited impact on hepatitis B testing completion. Future research should evaluate other intervention approaches to improving hepatitis B testing rates among Chinese in North America.

Evaluation of a Hepatitis B Lay Health Worker Intervention for Chinese Americans and Canadians

PubMed Central

Taylor, Vicky M.; Hislop, T. Gregory; Tu, Shin-Ping; Teh, Chong; Acorda, Elizabeth; Yip, Mei-Po; Woodall, Erica; Yasui, Yutaka

2009-01-01

Hepatitis B testing is recommended for immigrants from countries where hepatitis B infection is endemic. However, only about one-half of Chinese in North America have received hepatitis B testing. We conducted a randomized controlled trial to evaluate the effectiveness of a hepatitis B lay health worker intervention for Chinese Americans/Canadians. Four hundred and sixty individuals who had never been tested for hepatitis B were identified from community-based surveys of Chinese conducted in Seattle, Washington, and Vancouver, British Columbia. These individuals were randomly assigned to receive a hepatitis B lay health worker intervention or a direct mailing of physical activity educational materials. Follow-up surveys were completed six months after randomization. Self-reported hepatitis B testing was verified through medical records review. A total of 319 individuals responded to the follow-up survey (69% response rate). Medical records data verified hepatitis B testing since randomization for nine (6%) of the 142 experimental group participants and three (2%) of the 177 control group participants (p=0.04). At follow-up, a higher proportion of individuals in the experimental arm than individuals in the control arm knew that hepatitis B can be spread by razors (p<0.001) and during sexual intercourse (p=0.07). Our findings suggest that lay health worker interventions can impact hepatitis B-related knowledge. However, our hepatitis B lay health worker intervention had a very limited impact on hepatitis B testing completion. Future research should evaluate other intervention approaches to improving hepatitis B testing rates among Chinese in North America. PMID:19127416

Animals In Synchrotrons: Overcoming Challenges For High-Resolution, Live, Small-Animal Imaging

NASA Astrophysics Data System (ADS)

Donnelley, Martin; Parsons, David; Morgan, Kaye; Siu, Karen

2010-07-01

Physiological studies in small animals can be complicated, but the complexity is increased dramatically when performing live-animal synchrotron X-ray imaging studies. Our group has extensive experience in high-resolution live-animal imaging at the Japanese SPring-8 synchrotron, primarily examining airways in two-dimensions. These experiments normally image an area of 1.8 mm×1.2 mm at a pixel resolution of 0.45 μm and are performed with live, intact, anaesthetized mice. There are unique challenges in this experimental setting. Importantly, experiments must be performed in an isolated imaging hutch not specifically designed for small-animal imaging. This requires equipment adapted to remotely monitor animals, maintain their anesthesia, and deliver test substances while collecting images. The horizontal synchrotron X-ray beam has a fixed location and orientation that limits experimental flexibility. The extremely high resolution makes locating anatomical regions-of-interest slow and can result in a high radiation dose, and at this level of magnification small animal movements produce motion-artifacts that can render acquired images unusable. Here we describe our experimental techniques and how we have overcome several challenges involved in performing live mouse synchrotron imaging. Experiments have tested different mouse strains, with hairless strains minimizing overlying skin and hair artifacts. Different anesthetics have also be trialed due to the limited choices available at SPring-8. Tracheal-intubation methods have been refined and controlled-ventilation is now possible using a specialized small-animal ventilator. With appropriate animal restraint and respiratory-gating, motion-artifacts have been minimized. The animal orientation (supine vs. head-high) also appears to affect animal physiology, and can alter image quality. Our techniques and image quality at SPring-8 have dramatically improved and in the near future we plan to translate this experience to the Imaging and Medical Beamline at the Australian Synchrotron. Overcoming these challenges has permitted increasingly sophisticated imaging of animals with synchrotron X-rays, and we expect a bright future for these techniques.

Animals In Synchrotrons: Overcoming Challenges For High-Resolution, Live, Small-Animal Imaging

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

Donnelley, Martin; Parsons, David; Women's and Children's Health Research Institute, Adelaide, South Australia

Physiological studies in small animals can be complicated, but the complexity is increased dramatically when performing live-animal synchrotron X-ray imaging studies. Our group has extensive experience in high-resolution live-animal imaging at the Japanese SPring-8 synchrotron, primarily examining airways in two-dimensions. These experiments normally image an area of 1.8 mmx1.2 mm at a pixel resolution of 0.45 {mu}m and are performed with live, intact, anaesthetized mice.There are unique challenges in this experimental setting. Importantly, experiments must be performed in an isolated imaging hutch not specifically designed for small-animal imaging. This requires equipment adapted to remotely monitor animals, maintain their anesthesia, andmore » deliver test substances while collecting images. The horizontal synchrotron X-ray beam has a fixed location and orientation that limits experimental flexibility. The extremely high resolution makes locating anatomical regions-of-interest slow and can result in a high radiation dose, and at this level of magnification small animal movements produce motion-artifacts that can render acquired images unusable. Here we describe our experimental techniques and how we have overcome several challenges involved in performing live mouse synchrotron imaging.Experiments have tested different mouse strains, with hairless strains minimizing overlying skin and hair artifacts. Different anesthetics have also be trialed due to the limited choices available at SPring-8. Tracheal-intubation methods have been refined and controlled-ventilation is now possible using a specialized small-animal ventilator. With appropriate animal restraint and respiratory-gating, motion-artifacts have been minimized. The animal orientation (supine vs. head-high) also appears to affect animal physiology, and can alter image quality. Our techniques and image quality at SPring-8 have dramatically improved and in the near future we plan to translate this experience to the Imaging and Medical Beamline at the Australian Synchrotron.Overcoming these challenges has permitted increasingly sophisticated imaging of animals with synchrotron X-rays, and we expect a bright future for these techniques.« less

Earth-based construction material field tests characterization in the Alto Douro Wine Region

NASA Astrophysics Data System (ADS)

Cardoso, Rui; Pinto, Jorge; Paiva, Anabela; Lanzinha, João Carlos

2017-12-01

The Alto Douro Wine Region, located in the northeast of Portugal, a UNESCO World Heritage Site, presents an abundant vernacular building heritage. This building technology is based on a timber framed structure filled with a composite earth-based material. A lack of scientific studies related to this technology is evident, furthermore, principally in rural areas, this traditional building stock is highly deteriorated and damaged because of the rareness of conservation and strengthening works, which is partly related to the non-engineered character of this technology and to the knowledge loosed on that technique. Those aspects motivated the writing of this paper, whose main purpose is the physical and chemical characterization of the earth-based material applied in the tabique buildings of that region through field tests. Consequently, experimental work was conducted and the results obtained allowed, among others, the proposal of a series of adequate field tests. At our knowledge, this is the first time field tests are undertaken for tabique technology. This information will provide the means to assess the suitability of a given earth-based material with regards to this technology. The knowledge from this study could also be very useful for the development of future normative documents and as a reference for architects and engineers that work with this technology to guide and regulate future conservation, rehabilitation or construction processes helping to preserve this important legacy.

Human perception testing methodology for evaluating EO/IR imaging systems

NASA Astrophysics Data System (ADS)

Graybeal, John J.; Monfort, Samuel S.; Du Bosq, Todd W.; Familoni, Babajide O.

2018-04-01

The U.S. Army's RDECOM CERDEC Night Vision and Electronic Sensors Directorate (NVESD) Perception Lab is tasked with supporting the development of sensor systems for the U.S. Army by evaluating human performance of emerging technologies. Typical research questions involve detection, recognition and identification as a function of range, blur, noise, spectral band, image processing techniques, image characteristics, and human factors. NVESD's Perception Lab provides an essential bridge between the physics of the imaging systems and the performance of the human operator. In addition to quantifying sensor performance, perception test results can also be used to generate models of human performance and to drive future sensor requirements. The Perception Lab seeks to develop and employ scientifically valid and efficient perception testing procedures within the practical constraints of Army research, including rapid development timelines for critical technologies, unique guidelines for ethical testing of Army personnel, and limited resources. The purpose of this paper is to describe NVESD Perception Lab capabilities, recent methodological improvements designed to align our methodology more closely with scientific best practice, and to discuss goals for future improvements and expanded capabilities. Specifically, we discuss modifying our methodology to improve training, to account for human fatigue, to improve assessments of human performance, and to increase experimental design consultation provided by research psychologists. Ultimately, this paper outlines a template for assessing human perception and overall system performance related to EO/IR imaging systems.

A Pilot Study of Women’s Affective Responses to Common and Uncommon Forms of Aerobic Exercise

PubMed Central

Stevens, Courtney J.; Smith, Jane Ellen; Bryan, Angela D.

2015-01-01

Objective To test the extent to which participants exposed to an uncommon versus common exercise stimulus would result in more favourable affect at post task. Design Experimental design. Participants, (N = 120) American women aged 18–45 years, were randomly assigned to complete 30-minutes of either the uncommon (HOOP; n = 58) or common (WALK; n = 62) exercise stimulus. Main Outcome Measures Self-reported affect and intentions for future exercise were measured before and after the 30-minute exercise bout. Results Analyses of covariance (ANCOVA) were run to compare post-task affect across the HOOP and WALK conditions. At post-task, participants assigned to HOOP reported more positively valenced affect, higher ratings of positive activated affect, lower ratings of negative deactivated affect, and stronger intentions for future aerobic exercise compared to participants assigned to WALK. Conclusions Participants who completed an uncommon bout of aerobic exercise (HOOP) reported more favourable affect post-exercise, as well as stronger intentions for future exercise, compared to participants who completed a common bout of aerobic exercise (WALK). Future work using a longitudinal design is needed to understand the relationships between familiarity with an exercise stimulus, affective responses to exercise, motivation for future exercise behaviour, and exercise maintenance over time. PMID:26394246

Neural and Behavioral Evidence for the Role of Mental Simulation in Meaning in Life

PubMed Central

Waytz, Adam; Hershfield, Hal E; Tamir, Diana I

2014-01-01

Mental simulation, the process of self-projection into alternate temporal, spatial, social, or hypothetical realities is a distinctively human capacity. Numerous lines of research also suggest that the tendency for mental simulation is associated with enhanced meaning. The present research tests this association specifically examining the relationship between two forms of simulation (temporal and spatial) and meaning in life. Study 1 uses neuroimaging to demonstrate that enhanced connectivity in the medial temporal lobe network, a subnetwork of the brain’s default network implicated in prospection and retrospection, correlates with self-reported meaning in life. Study 2 demonstrates that experimentally inducing people to think about the past or future versus the present enhances self-reported meaning in life, through the generation of more meaningful events. Study 3 demonstrates that experimentally inducing people to think specifically versus generally about the past or future enhances self-reported meaning in life. Study 4 turns to spatial simulation to demonstrate that experimentally inducing people to think specifically about an alternate spatial location (from the present) increases meaning derived from this simulation compared to thinking generally about another location or specifically about one’s present location. Study 5 demonstrates that experimentally inducing people to think about an alternate spatial location versus one’s present location enhances meaning in life, through meaning derived from this simulation. Study 6 demonstrates that simply asking people to imagine completing a measure of meaning in life in an alternate location compared to asking them to do so in their present location enhances reports of meaning. This research sheds light on an important determinant of meaning in life and suggests that undirected mental simulation benefits psychological well-being. PMID:25603379

Progression of Ebola Therapeutics During the 2014-2015 Outbreak.

PubMed

Mendoza, Emelissa J; Qiu, Xiangguo; Kobinger, Gary P

2016-02-01

The recent Ebola virus (EBOV) outbreak in West Africa was the deadliest EBOV epidemic in history, highlighting the need for a safe and efficacious treatment against EBOV disease (EVD). In the absence of an approved treatment, experimental drugs were utilized under compassionate grounds hoping to diminish EVD-associated morbidity and mortality. As more data were collected from safety studies, Phase II/III clinical trials were introduced in Guinea, Sierra Leone, and Liberia to test promising candidates, including small-molecule drugs, RNA-based treatments, and antibody-based therapies. In this review, we summarize the use of, and preliminary observations from, current clinical trials with EVD therapeutics, shedding light on experimental drug selection, emergency clinical evaluation, and the impact these factors may have on future infectious disease outbreaks. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Man in space: The use of animal models

NASA Astrophysics Data System (ADS)

Ballard, Rodney W.; Souza, Kenneth A.

Animals have traditionally preceded man into space. During animal and human travels in space over the past almost 30 years, numerous anatomical, physiological, and biochemical changes have been observed. In order to safely qualify humans for extended duration space missions, scientific research needs to be performed. It may be possible to achieve many of these research goals with flight crews serving as experimental subjects; however, to do this with human subjects alone is impractical. Therefore, the use of animal surrogates as experimental subjects is essential to provide the missing information on the effects of spaceflights, to validate countermeasures, and to test medical treatment techniques which will be necessary for long duration missions. This research to assure human health, safety, and productivity in future extended duration space flights will include flights on NASA's Space Shuttle, unmanned biosatellites, and the Space Station Freedom.

Predicting the stochastic guiding of kinesin-driven microtubules in microfabricated tracks: a statistical-mechanics-based modeling approach.

PubMed

Lin, Chih-Tin; Meyhofer, Edgar; Kurabayashi, Katsuo

2010-01-01

Directional control of microtubule shuttles via microfabricated tracks is key to the development of controlled nanoscale mass transport by kinesin motor molecules. Here we develop and test a model to quantitatively predict the stochastic behavior of microtubule guiding when they mechanically collide with the sidewalls of lithographically patterned tracks. By taking into account appropriate probability distributions of microscopic states of the microtubule system, the model allows us to theoretically analyze the roles of collision conditions and kinesin surface densities in determining how the motion of microtubule shuttles is controlled. In addition, we experimentally observe the statistics of microtubule collision events and compare our theoretical prediction with experimental data to validate our model. The model will direct the design of future hybrid nanotechnology devices that integrate nanoscale transport systems powered by kinesin-driven molecular shuttles.

Man in space: the use of animal models.

PubMed

Ballard, R W; Souza, K A

1991-01-01

Animals have traditionally preceded man into space. During animal and human travels in space over the past almost 30 years, numerous anatomical, physiological, and biochemical changes have been observed. In order to safely qualify humans for extended duration space missions, scientific research needs to be performed. It may be possible to achieve many of these research goals with flight crews serving as experimental subjects; however, to do this with human subjects alone is impractical. Therefore, the use of animal surrogates as experimental subjects is essential to provide the missing information on the effects of spaceflights, to validate countermeasures, and to test medical treatment techniques which will be necessary for long duration missions. This research to assure human health, safety, and productivity in future extended duration space flights will include flights on NASA's Space Shuttle, unmanned biosatellites, and the Space Station Freedom.

The experimental evidence for weight-loss treatment of essential hypertension: a critical review.

PubMed Central

Hovell, M F

1982-01-01

The empirical evidence concerning the therapeutic effects of weight loss for hypertension treatment was reviewed. Interventions were critically reviewed for strength of measures and experimental design. Six of 21 intervention studies proved to be methodologically strong. However, only one study was considered a randomized clinical trial, testing the combined effects of weight reduction and pharmacological treatment of hypertension. Average blood pressure decrease obtained from the methodologically strongest studies was -21 mmHg and -13 mmHg, for systolic and diastolic measures, respectively. This magnitude change suggests that weight loss may be a clinically and statistically significant treatment. Confounding and bias variables, such as adherence to diet, medication, salt consumption, etc., were discussed and future areas of research were outlined. It was concluded that weight loss appears to be an effective and safe treatment of hypertension. PMID:7039371

Advanced experimental techniques for transonic wind tunnels - Final lecture

NASA Technical Reports Server (NTRS)

Kilgore, Robert A.

1987-01-01

A philosophy of experimental techniques is presented, suggesting that in order to be successful, one should like what one does, have the right tools, stick to the job, avoid diversions, work hard, interact with people, be informed, keep it simple, be self sufficient, and strive for perfection. Sources of information, such as bibliographies, newsletters, technical reports, and technical contacts and meetings are recommended. It is pointed out that adaptive-wall test sections eliminate or reduce wall interference effects, and magnetic suspension and balance systems eliminate support-interference effects, while the problem of flow quality remains with all wind tunnels. It is predicted that in the future it will be possible to obtain wind tunnel results at the proper Reynolds number, and the effects of flow unsteadiness, wall interference, and support interference will be eliminated or greatly reduced.

The Single Event Effect Characteristics of the 486-DX4 Microprocessor

NASA Technical Reports Server (NTRS)

Kouba, Coy; Choi, Gwan

1996-01-01

This research describes the development of an experimental radiation testing environment to investigate the single event effect (SEE) susceptibility of the 486-DX4 microprocessor. SEE effects are caused by radiation particles that disrupt the logic state of an operating semiconductor, and include single event upsets (SEU) and single event latchup (SEL). The relevance of this work can be applied directly to digital devices that are used in spaceflight computer systems. The 486-DX4 is a powerful commercial microprocessor that is currently under consideration for use in several spaceflight systems. As part of its selection process, it must be rigorously tested to determine its overall reliability in the space environment, including its radiation susceptibility. The goal of this research is to experimentally test and characterize the single event effects of the 486-DX4 microprocessor using a cyclotron facility as the fault-injection source. The test philosophy is to focus on the "operational susceptibility," by executing real software and monitoring for errors while the device is under irradiation. This research encompasses both experimental and analytical techniques, and yields a characterization of the 486-DX4's behavior for different operating modes. Additionally, the test methodology can accommodate a wide range of digital devices, such as microprocessors, microcontrollers, ASICS, and memory modules, for future testing. The goals were achieved by testing with three heavy-ion species to provide different linear energy transfer rates, and a total of six microprocessor parts were tested from two different vendors. A consistent set of error modes were identified that indicate the manner in which the errors were detected in the processor. The upset cross-section curves were calculated for each error mode, and the SEU threshold and saturation levels were identified for each processor. Results show a distinct difference in the upset rate for different configurations of the on-chip cache, as well as proving that one vendor is superior to the other in terms of latchup susceptibility. Results from this testing were also used to provide a mean-time-between-failure estimate of the 486-DX4 operating in the radiation environment for the International Space Station.

Fermilab | Science at Fermilab | Theory

Science.gov Websites

future direction of experimental programs. Experimental results, in turn, can confirm or rule out GPS satellites, rely on the advances made in experimental and theoretical physics. Without a firm

Evaluation of World Health Organization Multi-Professional Patient Safety Curriculum Topics in Nursing Education: Pre-test, post-test, none-experimental study.

PubMed

Mansour, Mansour; Skull, Alice; Parker, Michael

2015-01-01

The Multi-professional Patient Safety Curriculum Guide was launched by the World Health Organization to develop a patient safety-friendly curriculum in health education. The aim of this study was to evaluate the impact of teaching related to two topics from the Patient Safety Curriculum Guide on student nurses' knowledge and attitudes toward patient safety. A pretest, posttest, nonexperimental design was used. Patient safety education questionnaires were distributed to a convenience sample of 181 nursing students before the intervention, and 141 questionnaires after the intervention in one university in the East of England. The intervention consisted of two face-to-face lectures and one facilitated group work discussion. Seventy-one responses from pre- and posttest stages were matched. Paired t test, McNemar's test, and frequency measures were used for data analysis. The findings suggest that there are statistically significant differences in the subscales of the error and patient safety and personal influence over safety. The differences in the students' answers on patient safety knowledge before and after the interventions were not statistically significant. Although the student nurses highly commended the teaching delivered in this study, the use of experimental design in future curriculum evaluation may provide a more complementary insight to the findings of this study. Copyright © 2015 Elsevier Inc. All rights reserved.

Safety and Environment- Masterplan 2020 of DLR's Rocket Test Center Lampoldhausen

NASA Astrophysics Data System (ADS)

Haberzettl, Andreas; Dommers, Michael

2013-09-01

The German Aerospace Center DLR is the German research institute with approximately 7000 employees in 16 domestic locations. Among the research priorities of the German Aerospace Center DLR includes aerospace, energy and transport. DLR is institutionally supported by federal and state governments.Next funding sources arise in the context of third-party funds business (contract research and public contracts and subsidiaries). Main activities of the test center Lampoldshausen are testing of ARIANE's main and upper stage engines in the frame of ESA contracts.In the last years the test center of the DLR in Lampoldshausen has grown strongly, so that the number of employees is actually of about 230. The testing department is mainly responsible for rocket combustion testing according to customer requirements.Two kinds of test facilities are operated, sea level test benches and the altitude simulation test facilities.In addition to the DLR's growth also the activities of the industrial partner ASTRIUM has been elevated so that actually nearly 600 employees are present on site Lampoldshausen.The management of the site in relation to safety and security requires special measures with special respect to the presence of more people inside the testing area in order to guarantee trouble-free and safe experimental operation onsite the DLR's test plants. In order to meet with the future needs of continuing growth, the security and safety requirements have to be adopted.This report gives comprehensive outlook information about future possible scenarios of our coming tasks.Main driving force for future requests is the evolution of the rocket ARIANE. The testing of the new upper stage test facility for ARIANE 5 midlife evolution has been started. A new test position P5.2 is foreseen to perform the qualification of the new upper stage with the VINCI engine. This project will be very complex, in parallel running operation processes will require special procedures related to the overall safety of the test center.The site of Lampoldshausen with its test and supply facilities is subject to the restrictions of the German law BundesImissionsSchutzGesetz (derived from the European SEVESO-II directive) and its relevant ordinances, especially the Hazardous Incident Ordinance. Because of the complex framework effort which guarantees safety and security, Lampoldshausen has invested in people and processes in order to respect the restrictions of all relevant laws and ordinances as well as to guarantee the protection of people and the environment.Therefor a very special Master plan has been developed, with the goal to rearrange the complete testing area in order to be able to divide the area in certain sectors (testing range, technology and bureau) so that future testing enterprises will not affect almost free testing activities inside the site as it is in the present status.The paper provides comprehensive information related to the planned innovations including detailed background facts related to the foreseen safety and security standard applications.

Enhancing quality of carbon nanotubes through a real-time controlled CVD process with application to next-generation nanosystems

NASA Astrophysics Data System (ADS)

Laxminarayana, Karthik; Jalili, Nader

2004-07-01

Nanocrystals and nanostructures will be the building blocks for future materials that will exhibit enhanced or entirely new combinations of properties with tremendous opportunity for novel technologies that can have far-reaching impact on our society. It is, however, realized that a major challenge for the near future is the design, synthesis and integration of nanostructures to develop functional nanosystems. In view of this, this exploratory research seeks to facilitate the development of a controlled and deterministic framework for nanomanufacturing of nanotubes as the most suitable choice among nanostructures for a plethora of potential applications in areas such as nanoelectronic devices, biological probes, fuel cell electrodes, supercapacitors and filed emission devices. Specifically, this paper proposes to control and maintain the most common nanotube growth parameters (i.e., reaction temperature and gas flow rate) through both software and hardware modifications. The influence of such growth parameters in a CVD process on some of the most vital and crucial aspects of nanotubes (e.g., length, diameter, yield, growth rate and structure) can be utilized to arrive at some unique and remarkable properties for the nanotubes. The objective here is, therefore, to control the process parameters to pinpoint accuracy, which would enable us to fabricate nanotubes having the desired properties and thereby maximize their ability to function at its fullest potential. To achieve this and in order to provide for experimental validation of the proposed research program, an experimental test-bed using the nanotube processing test chamber and a mechatronics workstation are being constructed.

Experimental Evaluation of Suitability of Selected Multi-Criteria Decision-Making Methods for Large-Scale Agent-Based Simulations.

PubMed

Tučník, Petr; Bureš, Vladimír

2016-01-01

Multi-criteria decision-making (MCDM) can be formally implemented by various methods. This study compares suitability of four selected MCDM methods, namely WPM, TOPSIS, VIKOR, and PROMETHEE, for future applications in agent-based computational economic (ACE) models of larger scale (i.e., over 10 000 agents in one geographical region). These four MCDM methods were selected according to their appropriateness for computational processing in ACE applications. Tests of the selected methods were conducted on four hardware configurations. For each method, 100 tests were performed, which represented one testing iteration. With four testing iterations conducted on each hardware setting and separated testing of all configurations with the-server parameter de/activated, altogether, 12800 data points were collected and consequently analyzed. An illustrational decision-making scenario was used which allows the mutual comparison of all of the selected decision making methods. Our test results suggest that although all methods are convenient and can be used in practice, the VIKOR method accomplished the tests with the best results and thus can be recommended as the most suitable for simulations of large-scale agent-based models.

Configuration and Sizing of a Test Fixture for Panels Under Combined Loads

NASA Technical Reports Server (NTRS)

Lovejoy, Andrew E.

2006-01-01

Future air and space structures are expected to utilize composite panels that are subjected to combined mechanical loads, such as bi-axial compression/tension, shear and pressure. Therefore, the ability to accurately predict the buckling and strength failures of such panels is important. While computational analysis can provide tremendous insight into panel response, experimental results are necessary to verify predicted performances of these panels to judge the accuracy of computational methods. However, application of combined loads is an extremely difficult task due to the complex test fixtures and set-up required. Presented herein is a comparison of several test set-ups capable of testing panels under combined loads. Configurations compared include a D-box, a segmented cylinder and a single panel set-up. The study primarily focuses on the preliminary sizing of a single panel test configuration capable of testing flat panels under combined in-plane mechanical loads. This single panel set-up appears to be best suited to the testing of both strength critical and buckling critical panels. Required actuator loads and strokes are provided for various square, flat panels.

Podcasts on Mobile Devices as a Read-Aloud Testing Accommodation in Middle School Science Assessment

NASA Astrophysics Data System (ADS)

McMahon, Don; Wright, Rachel; Cihak, David F.; Moore, Tara C.; Lamb, Richard

2016-04-01

The purpose of this study was to examine the effect of a digitized podcast to deliver read-aloud testing accommodations on mobile devices to students with disabilities and reading difficulties. The total sample for this study included 47 middle school students with reading difficulties. Of the 47 students, 16 were identified as students with disabilities who received special education services. Participants were randomly assigned to three experimental testing conditions, standard administration, teacher-controlled read-aloud in traditional group delivery format, and student-controlled read-aloud delivered as a podcast and accessed on a mobile device, and given sample end-of-year science assessments. Based on a factorial analysis of variances, with test conditions and student status as the fixed factors, both student groups demonstrated statistically significant gains based on their testing conditions. Results support the use of podcast delivery as a viable alternative to the traditional teacher-delivered read-aloud test accommodation. Conclusions are discussed in the context of universal design for learning testing accommodations for future research and practice.

Strategic Mobility 21: Baseline Joint Experimentation Campaign Plan

DTIC Science & Technology

2008-06-19

including energy. The Value Stream Analysis Future State then designed Kaizens (process optimizations) for an improved Future State to help drive waste...Recommended Improvements and Experimentation Opportunities Initial recommended Kaizens (improvement opportunities) for waste reduction, constraint...Trucking, Service Craft Logistics, BNSF, and Madison Warehouse, Inc. • Kaizen 1 (Figure 17): Full upload electronically of the Dole ANS files • Kaizen

Pure moment testing for spinal biomechanics applications: Fixed versus sliding ring cable-driven test designs.

PubMed

Eguizabal, Johnny; Tufaga, Michael; Scheer, Justin K; Ames, Christopher; Lotz, Jeffrey C; Buckley, Jenni M

2010-05-07

In vitro multi-axial bending testing using pure moment loading conditions has become the standard in evaluating the effects of different types of surgical intervention on spinal kinematics. Simple, cable-driven experimental set-ups have been widely adopted because they require little infrastructure. Traditionally, "fixed ring" cable-driven experimental designs have been used; however, there have been concerns with the validity of this set-up in applying pure moment loading. This study involved directly comparing the loading state induced by a traditional "fixed ring" apparatus versus a novel "sliding ring" approach. Flexion-extension bending was performed on an artificial spine model and a single cadaveric test specimen, and the applied loading conditions to the specimen were measured with an in-line multiaxial load cell. The results showed that the fixed ring system applies flexion-extension moments that are 50-60% less than the intended values. This design also imposes non-trivial anterior-posterior shear forces, and non-uniform loading conditions were induced along the length of the specimen. The results of this study indicate that fixed ring systems have the potential to deviate from a pure moment loading state and that our novel sliding ring modification corrects this error in the original test design. This suggests that the proposed sliding ring design should be used for future in vitro spine biomechanics studies involving a cable-driven pure moment apparatus. Copyright 2010 Elsevier Ltd. All rights reserved.

The Impact of Environmental Design on Doffing Personal Protective Equipment in a Healthcare Environment: A Formative Human Factors Trial.

PubMed

Herlihey, Tracey A; Gelmi, Stefano; Cafazzo, Joseph A; Hall, Trevor N T

2017-06-01

OBJECTIVE To explore the impact of environmental design on doffing personal protective equipment in a simulated healthcare environment. METHODS A mixed-methods approach was used that included human-factors usability testing and qualitative questionnaire responses. A patient room and connecting anteroom were constructed for testing purposes. This experimental doffing area was designed to overcome the environmental failures identified in a previous study and was not constructed based on any generalizable hospital standard. RESULTS In total, 72 healthcare workers from Ontario, Canada, took part in the study and tested the simulated doffing area. The following environmental design changes were tested and were deemed effective: increasing prominence of color-coded zones; securing disinfectant wipes and hand sanitizer; outlining disposal bins locations; providing mirrors to detect possible contamination; providing hand rails to assist with doffing; and restricting the space to doff. Further experimentation and iterative design are required with regard to several important features: positioning the disposal bins for safety, decreasing the risk of contamination and user accessibility; optimal positioning of mirrors for safety; communication within the team; and positioning the secondary team member for optimal awareness. Additional design suggestions also emerged during this study, and they require future investigation. CONCLUSIONS This study highlights the importance of the environment on doffing personal protective equipment in a healthcare setting. Iterative testing and modification of the design of the environment (doffing area) are important to enhancing healthcare worker safety. Infect Control Hosp Epidemiol 2017;38:712-717.

ENHANCED PRACTICAL PHOTOSYNTHETIC CO2 MITIGATION

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

Dr. Gregory Kremer; Dr. David J. Bayless; Dr. Morgan Vis

2001-07-25

This quarterly report documents significant achievements in the Enhanced Practical Photosynthetic CO{sub 2} Mitigation project during the period from 4/03/2001 through 7/02/2001. Most of the achievements are milestones in our efforts to complete the tasks and subtasks that constitute the project objectives. Note that this version of the quarterly technical report is a revision to add the reports from subcontractors Montana State and Oak Ridge National Laboratories The significant accomplishments for this quarter include: Development of an experimental plan and initiation of experiments to create a calibration curve that correlates algal chlorophyll levels with carbon levels (to simplify future experimentalmore » procedures); Completion of debugging of the slug flow reactor system, and development of a plan for testing the pressure drop of the slug flow reactor; Design and development of a new bioreactor screen design which integrates the nutrient delivery drip system and the harvesting system; Development of an experimental setup for testing the new integrated drip system/harvesting system; Completion of model-scale bioreactor tests examining the effects of CO{sub 2} concentration levels and lighting levels on Nostoc 86-3 growth rates; Completion of the construction of a larger model-scale bioreactor to improve and expand testing capabilities and initiation of tests; Substantial progress on construction of a pilot-scale bioreactor; and Preliminary economic analysis of photobioreactor deployment. Plans for next quarter's work are included in the conclusions. A preliminary economic analysis is included as an appendix.« less

The Power of the Virtual Ideal Self in Weight Control: Weight-Reduced Avatars Can Enhance the Tendency to Delay Gratification and Regulate Dietary Practices.

PubMed

Kuo, Hsu-Chan; Lee, Chun-Chia; Chiou, Wen-Bin

2016-02-01

The tendency to discount larger future benefits in favor of smaller immediate gains (i.e., temporal discounting) is relevant to the issue of obesity. Successful weight loss requires individuals to sacrifice immediate culinary pleasures in favor of future health gains. Based on the notion that increasing the vividness of one's future self may mitigate temporal discounting and promote the ability to delay gratification, we examined whether viewing one's weight-reduced self (i.e., the ideal self) in a virtual environment can decrease temporal discounting and lead to better regulation of dietary practices. Seventy-six undergraduates who had reported an intention to lose weight were recruited to participate in a laboratory experiment and were randomly assigned to interact with either the weight-reduced self (experimental condition) or the present self (control condition) by looking into a dressing mirror in a virtual fitting room. A temporal-discounting task and a taste test were subsequently administered. Results showed that, compared with control participants, participants who viewed their weight-reduced avatars ate less ice cream in a taste test and were more likely to choose a sugar-free drink as a reward. The discounting rate mediated the association between the avatar manipulation and the amount of ice cream eaten in the subsequent taste test. Overall, our findings suggest that a computer-generated image of one's weight-reduced self may assist in resisting impulses that promote immediate gratification over delayed benefits. This research provides a new approach for controlling impulsive behavior such as dietary regulation and weight control.

Behavioral Assessment of Listening Effort Using a Dual-Task Paradigm.

PubMed

Gagné, Jean-Pierre; Besser, Jana; Lemke, Ulrike

2017-01-01

Published investigations ( n = 29) in which a dual-task experimental paradigm was employed to measure listening effort during speech understanding in younger and older adults were reviewed. A summary of the main findings reported in the articles is provided with respect to the participants' age-group and hearing status. Effects of different signal characteristics, such as the test modality, on dual-task outcomes are evaluated, and associations with cognitive abilities and self-report measures of listening effort are described. Then, several procedural issues associated with the use of dual-task experiment paradigms are discussed. Finally, some issues that warrant future research are addressed. The review revealed large variability in the dual-task experimental paradigms that have been used to measure the listening effort expended during speech understanding. The differences in experimental procedures used across studies make it difficult to draw firm conclusions concerning the optimal choice of dual-task paradigm or the sensitivity of specific paradigms to different types of experimental manipulations. In general, the analysis confirmed that dual-task paradigms have been used successfully to measure differences in effort under different experimental conditions, in both younger and older adults. Several research questions that warrant further investigation in order to better understand and characterize the intricacies of dual-task paradigms were identified.

Behavioral Assessment of Listening Effort Using a Dual-Task Paradigm

PubMed Central

Besser, Jana; Lemke, Ulrike

2017-01-01

Published investigations (n = 29) in which a dual-task experimental paradigm was employed to measure listening effort during speech understanding in younger and older adults were reviewed. A summary of the main findings reported in the articles is provided with respect to the participants’ age-group and hearing status. Effects of different signal characteristics, such as the test modality, on dual-task outcomes are evaluated, and associations with cognitive abilities and self-report measures of listening effort are described. Then, several procedural issues associated with the use of dual-task experiment paradigms are discussed. Finally, some issues that warrant future research are addressed. The review revealed large variability in the dual-task experimental paradigms that have been used to measure the listening effort expended during speech understanding. The differences in experimental procedures used across studies make it difficult to draw firm conclusions concerning the optimal choice of dual-task paradigm or the sensitivity of specific paradigms to different types of experimental manipulations. In general, the analysis confirmed that dual-task paradigms have been used successfully to measure differences in effort under different experimental conditions, in both younger and older adults. Several research questions that warrant further investigation in order to better understand and characterize the intricacies of dual-task paradigms were identified. PMID:28091178

Development of an experimental approach to study coupled soil-plant-atmosphere processes using plant analogs

NASA Astrophysics Data System (ADS)

Trautz, Andrew C.; Illangasekare, Tissa H.; Rodriguez-Iturbe, Ignacio; Heck, Katharina; Helmig, Rainer

2017-04-01

The atmosphere, soils, and vegetation near the land-atmosphere interface are in a state of continuous dynamic interaction via a myriad of complex interrelated feedback processes which collectively, remain poorly understood. Studying the fundamental nature and dynamics of such processes in atmospheric, ecological, and/or hydrological contexts in the field setting presents many challenges; current experimental approaches are an important factor given a general lack of control and high measurement uncertainty. In an effort to address these issues and reduce overall complexity, new experimental design considerations (two-dimensional intermediate-scale coupled wind tunnel-synthetic aquifer testing using synthetic plants) for studying soil-plant-atmosphere continuum soil moisture dynamics are introduced and tested in this study. Validation of these experimental considerations, particularly the adoption of synthetic plants, is required prior to their application in future research. A comparison of three experiments with bare soil surfaces or transplanted with a Stargazer lily/limestone block was used to evaluate the feasibility of the proposed approaches. Results demonstrate that coupled wind tunnel-porous media experimentation, used to simulate field conditions, reduces complexity, and enhances control while allowing fine spatial-temporal resolution measurements to be made using state-of-the-art technologies. Synthetic plants further help reduce system complexity (e.g., airflow) while preserving the basic hydrodynamic functions of plants (e.g., water uptake and transpiration). The trends and distributions of key measured atmospheric and subsurface spatial and temporal variables (e.g., soil moisture, relative humidity, temperature, air velocity) were comparable, showing that synthetic plants can be used as simple, idealized, nonbiological analogs for living vegetation in fundamental hydrodynamic studies.

Ten years of research with the Socially Evaluated Cold Pressor Test: Data from the past and guidelines for the future.

PubMed

Schwabe, Lars; Schächinger, Hartmut

2018-06-01

Ten years ago, the Socially Evaluated Cold Pressor Test (SECPT) was introduced as a standardized protocol for the efficient experimental stress induction in humans. In short, the 3 min SECPT, which can be conducted by only a single experimenter, combines a physiological challenge (hand immersion into ice water) with socio-evaluative elements. The purpose of this article is twofold. First, we aim to evaluate the subjective and physiological responses elicited by the SECPT. To this end, we pooled data from 21 studies from our lab and systematically analyzed the response profile to the SECPT. Our analyses show that the SECPT leads, both in men and women, to striking increases in subjective stress levels, autonomic arousal, and cortisol, albeit the cortisol response is typically somewhat less pronounced than in the Trier Social Stress Test. Second, we aim to provide guidelines for conducting the SECPT, in order to foster homogenization of the SECPT procedure across (and within) labs. In sum, we argue that the SECPT is a highly efficient tool to induce stress and activate major stress systems in a laboratory context, in particular if the guidelines that we outline here are followed. Copyright © 2018 Elsevier Ltd. All rights reserved.

Is there a cannabis epidemic model? Evidence from France, Germany and USA.

PubMed

Legleye, Stephane; Piontek, Daniela; Pampel, Fred; Goffette, Céline; Khlat, Myriam; Kraus, Ludwig

2014-11-01

Cannabis is the most popular illicit drug in the world, but the process of its diffusion through the population has rarely been studied. The unfolding of the tobacco epidemic was accompanied by a shift in the educational gradient of users across generations. As a consequence, cannabis may show the same pattern of widening social inequalities. We test the diffusion hypotheses that a positive value in older cohorts - the more educated experimenting more - shifts to a negative one in younger cohorts - the more educated experimenting less, first for males and then females. Three nationwide subsamples (18-64 years old) of representative surveys conducted in France (n=21,818), Germany (n=7887) and USA (n=37,115) in 2009-2010 recorded age at cannabis experimentation (i.e., first use), educational level, gender, and age. Cumulative prevalence of experimentation was plotted for three retrospective cohorts (50-64, 35-49, 18-34 years old at data collection) and multivariate time-discrete logistic regression was computed by gender and generation to model age at experimentation adjusted on age at data collection and educational level. This latter was measured according to four categories derived from the International Standard Classification of Education (ISCED) and a relative (rather than absolute) index of education. The findings demonstrate a consistent pattern of evolution of the prevalence, gender ratio and educational gradient across generations and countries that support the hypothesis of an "epidemic" of cannabis experimentation that mimics the epidemic of tobacco. We provide evidence for a cannabis epidemic model similar to the tobacco epidemic model. In the absence of clues regarding the future of cannabis use, our findings demonstrate that the gender gap is decreasing and, based on the epidemic model, suggest that we may expect widening social inequalities in cannabis experimentation if cannabis use decreases in the future. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

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

Seapan, M.; Crynes, B.L.; Dale, S.

The objectives of this study were to analyze alternate crudes kinetic hydrotreatment data in the literature, develop a mathematical model for interpretation of these data, develop an experimental procedure and apparatus to collect accurate kinetic data, and finally, to combine the model and experimental data to develop a general model which, with a few experimental parameters, could be used in design of future hydrotreatment processes. These objectives were to cover a four year program (1980 to 1984) and were subjective to sufficient funding. Only partial funding has been available thus far to cover activities for two years. A hydrotreatment datamore » base is developed which contains over 2000 citations, stored in a microcomputer. About 50% of these are reviewed, classified and can be identified by feedstock, catalyst, reactor type and other process characteristics. Tests of published hydrodesulfurization data indicate the problems with simple n-th order, global kinetic models, and point to the value of developing intrinsic reaction kinetic models to describe the reaction processes. A Langmuir-Hinshelwood kinetic model coupled with a plug flow reactor design equation has been developed and used for published data evaluation. An experimental system and procedure have been designed and constructed, which can be used for kinetic studies. 30 references, 4 tables.« less

Willingness to Engage in Consensual Nonmonogamy Among Emerging Adults: A Structural Equation Analysis of Sexual Identity, Casual Sex Attitudes, and Gender.

PubMed

Sizemore, Kayla M; Olmstead, Spencer B

2017-01-01

Research on consensual nonmonogamy (CNM) has increased over the past decade. However, willingness to engage in CNM is an understudied phenomenon within this body of literature. Little research has examined the correlates of this aspect of CNM or focused on individuals in the developmental period of emerging adulthood. This study used multigroup structural equation modeling (SEM) to test a conceptual model of emerging adults' (ages 18 to 29; N = 890) willingness to engage in CNM. Results indicated that emerging adult experimentation/possibilities, sexual identity exploration, and permissive attitudes toward casual sex were all related to willingness to engage in CNM. Results also showed that the pathway from emerging adult experimentation/possibilities to willingness to engage in CNM was differentially mediated across gender. Specifically, for women there was an indirect (and positive) pathway from experimentation/possibilities to willingness to engage in CNM through sexual identity exploration. For men there was an indirect (and positive) pathway from experimentation/possibilities to willingness to engage in CNM through permissive attitudes toward casual sex. Implications for future studies on CNM among emerging adults are discussed.

Effects of victim presence and coercion in restorative justice: An experimental paradigm.

PubMed

Saulnier, Alana; Sivasubramaniam, Diane

2015-08-01

There is little experimental work examining the ways in which particular procedural features of restorative justice impact offenders. This research describes a new experimental paradigm designed to advance knowledge about causal relationships in restorative justice settings. Apologizing is a core component of restorative procedures, and can result in beneficial outcomes, but previous research suggests that coercion to apologize and the absence of victims in restorative procedures may negatively impact these outcomes. The experimental procedure elicited confessions and apologies for a transgression from participants (N = 101) in a deceptive paradigm. We manipulated coercion (coerced, not coerced) and victim presence (direct, surrogate, ambiguous) to test their effects on offenders' subjective experiences of offering an apology, as well as their effects on the quality of offenders' apologies. Findings indicated that the victim presence and coercion manipulations significantly impacted some of the subjective perceptions of apologizers, including perceptions of accountability and transgression finality. In addition, independent raters evaluated the degree to which the transgressor's apologies conveyed remorse, acceptance of guilt, and potential for dispute resolution. Victim presence and coercion consistently affected the ability of transgressors to convey high quality apologies. Implications for future research and restorative procedures are discussed. (c) 2015 APA, all rights reserved).

Evidence for Future Cognition in Animals

ERIC Educational Resources Information Center

Roberts, William A.

2012-01-01

Evidence concerning the possibility of mental time travel into the future by animals was reviewed. Both experimental laboratory studies and field observations were considered. Paradigms for the study of future anticipation and planning included inhibition of consumption of current food contingent on future receipt of either a larger quantity or…

The Effects of Sleep Deprivation on Soccer Skills.

PubMed

Pallesen, Ståle; Gundersen, Hilde Stokvold; Kristoffersen, Morten; Bjorvatn, Bjørn; Thun, Eirunn; Harris, Anette

2017-08-01

Many athletes sleep poorly due to stress, travel, and competition anxiety. In the present study, we investigated the effects of sleep deprivation on soccer skills (juggling, dribbling, ball control, continuous kicking, 20 and 40 m sprint, and 30 m sprint with changes of direction). In all, 19 male junior soccer players (14-19 years old) were recruited and participated in a cross-balanced experimental study comprising two conditions; habitual sleep and 24 hours sleep deprivation. In both conditions, testing took place between 8 a.m. and 10 a.m. Order of tests was counterbalanced. Each test was conducted once or twice in a sequence repeated three times. The results revealed a negative effect of sleep deprivation on the continuous kicking test. On one test, 30 meter sprint with directional changes, a significant condition × test repetition interaction was found, indicating a steeper learning curve in the sleep deprived condition from Test 1 to Test 2 and a steeper learning curve in the rested condition from Test 2 to Test 3. The results are discussed in terms of limitations and strengths, and recommendations for future studies are outlined.

A decade of insights into grassland ecosystem responses to global environmental change

USGS Publications Warehouse

Borer, Elizabeth T.; Grace, James B.; Harpole, W. Stanley; MacDougall, Andrew S.; Seabloom, Eric W.

2017-01-01

Earth’s biodiversity and carbon uptake by plants, or primary productivity, are intricately interlinked, underlie many essential ecosystem processes, and depend on the interplay among environmental factors, many of which are being changed by human activities. While ecological theory generalizes across taxa and environments, most empirical tests of factors controlling diversity and productivity have been observational, single-site experiments, or meta-analyses, limiting our understanding of variation among site-level responses and tests of general mechanisms. A synthesis of results from ten years of a globally distributed, coordinated experiment, the Nutrient Network (NutNet), demonstrates that species diversity promotes ecosystem productivity and stability, and that nutrient supply and herbivory control diversity via changes in composition, including invasions of non-native species and extinction of native species. Distributed experimental networks are a powerful tool for tests and integration of multiple theories and for generating multivariate predictions about the effects of global changes on future ecosystems.

An Adaptive Instability Suppression Controls Method for Aircraft Gas Turbine Engine Combustors

NASA Technical Reports Server (NTRS)

Kopasakis, George; DeLaat, John C.; Chang, Clarence T.

2008-01-01

An adaptive controls method for instability suppression in gas turbine engine combustors has been developed and successfully tested with a realistic aircraft engine combustor rig. This testing was part of a program that demonstrated, for the first time, successful active combustor instability control in an aircraft gas turbine engine-like environment. The controls method is called Adaptive Sliding Phasor Averaged Control. Testing of the control method has been conducted in an experimental rig with different configurations designed to simulate combustors with instabilities of about 530 and 315 Hz. Results demonstrate the effectiveness of this method in suppressing combustor instabilities. In addition, a dramatic improvement in suppression of the instability was achieved by focusing control on the second harmonic of the instability. This is believed to be due to a phenomena discovered and reported earlier, the so called Intra-Harmonic Coupling. These results may have implications for future research in combustor instability control.

Experimental research on a modular miniaturization nanoindentation device

NASA Astrophysics Data System (ADS)

Huang, Hu; Zhao, Hongwei; Mi, Jie; Yang, Jie; Wan, Shunguang; Yang, Zhaojun; Yan, Jiwang; Ma, Zhichao; Geng, Chunyang

2011-09-01

Nanoindentation technology is developing toward the in situ test which requires miniaturization of indentation instruments. This paper presents a miniaturization nanoindentation device based on the modular idea. It mainly consists of macro-adjusting mechanism, x-y precise positioning platform, z axis precise driving unit, and the load-depth measuring unit. The device can be assembled with different forms and has minimum dimensions of 200 mm × 135 mm × 200 mm. The load resolution is about 0.1 mN and the displacement resolution is about 10 nm. A new calibration method named the reference-mapping method is proposed to calibrate the developed device. Output performance tests and indentation experiments indicate the feasibility of the developed device and calibration method. This paper gives an example that combining piezoelectric actuators with flexure hinge to realize nanoindentation tests. Integrating a smaller displacement sensor, a more compact nanoindentation device can be designed in the future.

Advanced Visualization of Experimental Data in Real Time Using LiveView3D

NASA Technical Reports Server (NTRS)

Schwartz, Richard J.; Fleming, Gary A.

2006-01-01

LiveView3D is a software application that imports and displays a variety of wind tunnel derived data in an interactive virtual environment in real time. LiveView3D combines the use of streaming video fed into a three-dimensional virtual representation of the test configuration with networked communications to the test facility Data Acquisition System (DAS). This unified approach to real time data visualization provides a unique opportunity to comprehend very large sets of diverse forms of data in a real time situation, as well as in post-test analysis. This paper describes how LiveView3D has been implemented to visualize diverse forms of aerodynamic data gathered during wind tunnel experiments, most notably at the NASA Langley Research Center Unitary Plan Wind Tunnel (UPWT). Planned future developments of the LiveView3D system are also addressed.

A Test Apparatus for the MAJORANA DEMONSTRATOR Front-end Electronics

NASA Astrophysics Data System (ADS)

Singh, Harjit; Loach, James; Poon, Alan

2012-10-01

One of the most important experimental programs in neutrino physics is the search for neutrinoless double-beta decay. The MAJORANA collaboration is searching for this rare nuclear process in the Ge-76 isotope using HPGe detectors. Each detector is instrumented with high-performance electronics to read out and amplify the signals. The part of the electronics close to the detectors, consisting of a novel front-end circuit, cables and connectors, is made of radio-pure materials and is exceedingly delicate. In this work a dedicated test apparatus was created to benchmark the performance of the electronics before installation in the experiment. The apparatus was designed for cleanroom use, with fixtures to hold the components without contaminating them, and included the electronics necessary for power and readout. In addition to testing, the station will find longer term use in development of future versions of the electronics.

Development of an Active Twist Rotor for Wind: Tunnel Testing (NLPN97-310

NASA Technical Reports Server (NTRS)

Cesnik, Carlos E. S.; Shin, SangJoon; Hagood, Nesbitt W., IV

1998-01-01

The development of the Active Twist Rotor prototype blade for hub vibration and noise reduction studies is presented in this report. Details of the modeling, design, and manufacturing are explored. The rotor blade is integrally twisted by direct strain actuation. This is accomplished by distributing embedded piezoelectric fiber composites along the span of the blade. The development of the analysis framework for this type of active blade is presented. The requirements for the prototype blade, along with the final design results are also presented. A detail discussion on the manufacturing aspects of the prototype blade is described. Experimental structural characteristics of the prototype blade compare well with design goals, and preliminary bench actuation tests show lower performance than originally predicted. Electrical difficulties with the actuators are also discussed. The presented prototype blade is leading to a complete fully articulated four-blade active twist rotor system for future wind tunnel tests.

Using a cross section to train veterinary students to visualize anatomical structures in three dimensions

NASA Astrophysics Data System (ADS)

Provo, Judy; Lamar, Carlton; Newby, Timothy

2002-01-01

A cross section was used to enhance three-dimensional knowledge of anatomy of the canine head. All veterinary students in two successive classes (n = 124) dissected the head; experimental groups also identified structures on a cross section of the head. A test assessing spatial knowledge of the head generated 10 dependent variables from two administrations. The test had content validity and statistically significant interrater and test-retest reliability. A live-dog examination generated one additional dependent variable. Analysis of covariance controlling for performance on course examinations and quizzes revealed no treatment effect. Including spatial skill as a third covariate revealed a statistically significant effect of spatial skill on three dependent variables. Men initially had greater spatial skill than women, but spatial skills were equal after 8 months. A qualitative analysis showed the positive impact of this experience on participants. Suggestions for improvement and future research are discussed.

The 1986 Get Away Special Experimenter's Symposium

NASA Technical Reports Server (NTRS)

Thomas, Lawrence R. (Editor); Mosier, Frances L. (Editor)

1987-01-01

The 1986 Get Away Special (GAS) Experimenter's Symposium will provide a formal opportunity for GAS Experimenter's to share the results of their projects. The focus of this symposium is on payloads that will be flown in the future.

78 FR 51678 - Market Tests of Experimental Postal Products

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-21

...] Market Tests of Experimental Postal Products AGENCY: Postal Regulatory Commission. ACTION: Proposed rule... tests of experimental products. The proposed rules address the contents of market test filings, describe... Tests I. Introduction The Commission proposes to establish rules governing market tests of experimental...

James Webb Space Telescope optical simulation testbed IV: linear control alignment of the primary segmented mirror

NASA Astrophysics Data System (ADS)

Egron, Sylvain; Soummer, Rémi; Lajoie, Charles-Philippe; Bonnefois, Aurélie; Long, Joseph; Michau, Vincent; Choquet, Elodie; Ferrari, Marc; Leboulleux, Lucie; Levecq, Olivier; Mazoyer, Johan; N'Diaye, Mamadou; Perrin, Marshall; Petrone, Peter; Pueyo, Laurent; Sivaramakrishnan, Anand

2017-09-01

The James Webb Space Telescope (JWST) Optical Simulation Testbed (JOST) is a tabletop experiment designed to study wavefront sensing and control for a segmented space telescope, such as JWST. With the JWST Science and Operations Center co-located at STScI, JOST was developed to provide both a platform for staff training and to test alternate wavefront sensing and control strategies for independent validation or future improvements beyond the baseline operations. The design of JOST reproduces the physics of JWST's three-mirror anastigmat (TMA) using three custom aspheric lenses. It provides similar quality image as JWST (80% Strehl ratio) over a field equivalent to a NIRCam module, but at 633 nm. An Iris AO segmented mirror stands for the segmented primary mirror of JWST. Actuators allow us to control (1) the 18 segments of the segmented mirror in piston, tip, tilt and (2) the second lens, which stands for the secondary mirror, in tip, tilt and x, y, z positions. We present the most recent experimental results for the segmented mirror alignment. Our implementation of the Wavefront Sensing (WFS) algorithms using phase diversity is tested on simulation and experimentally. The wavefront control (WFC) algorithms, which rely on a linear model for optical aberrations induced by misalignment of the secondary lens and the segmented mirror, are tested and validated both on simulations and experimentally. In this proceeding, we present the performance of the full active optic control loop in presence of perturbations on the segmented mirror, and we detail the quality of the alignment correction.

Intolerance of Uncertainty: A Temporary Experimental Induction Procedure

PubMed Central

Mosca, Oriana; Lauriola, Marco; Carleton, R. Nicholas

2016-01-01

Background and Objectives Intolerance of uncertainty (IU) is a trans-diagnostic construct involved in anxiety and related disorders. Research focused on cross-sectional reporting, manipulating attitudes toward objective and impersonal events or on treatments designed to reduce IU in clinical populations. The current paper presents an experimental procedure for laboratory manipulations of IU and tests mediation hypotheses following the Intolerance of Uncertainty Model. Methods On pre-test, undergraduate volunteers (Study 1, n = 43;68% women. Study 2, n = 169;83.8% women) were asked to provide an idiosyncratic future negative life event. State-IU, Worry, Positive and Negative Affect were assessed after that a standardized procedure was used to identify event’s potential negative consequences. The same variables were assessed on post-test, after that participants were asked to read-through increasing and decreasing IU statements. Results Temporary changes on IU were consistently reproduced in both studies. Participants receiving increasing IU instructions reported greater state-IU, Worry and Negative Affect than those receiving decreasing IU instructions. However, this latter condition was not different from a control one (Study 2). Both studies revealed significant indirect effects of IU induction instructions on Worry and Negative Affect through state-IU. Limitations Both studies used undergraduate psychology students samples, younger than average population and predominantly female. Experimental manipulation and outcome measures belongs to the same semantic domain, uncertainty, potentially limiting generalizability. Conclusions Results supported the feasibility and efficacy of the proposed IU manipulation for non-clinical sample. Findings parallel clinical research showing that state-IU preceded Worry and Negative Affect states. PMID:27254099

LOX/Hydrocarbon Combustion Instability Investigation

NASA Technical Reports Server (NTRS)

Jensen, R. J.; Dodson, H. C.; Claflin, S. E.

1989-01-01

The LOX/Hydrocarbon Combustion Instability Investigation Program was structured to determine if the use of light hydrocarbon combustion fuels with liquid oxygen (LOX) produces combustion performance and stability behavior similar to the LOX/hydrogen propellant combination. In particular methane was investigated to determine if that fuel can be rated for combustion instability using the same techniques as previously used for LOX/hydrogen. These techniques included fuel temperature ramping and stability bomb tests. The hot fire program probed the combustion behavior of methane from ambient to subambient temperatures. Very interesting results were obtained from this program that have potential importance to future LOX/methane development programs. A very thorough and carefully reasoned documentation of the experimental data obtained is contained. The hot fire test logic and the associated tests are discussed. Subscale performance and stability rating testing was accomplished using 40,000 lb. thrust class hardware. Stability rating tests used both bombs and fuel temperature ramping techniques. The test program was successful in generating data for the evaluation of the methane stability characteristics relative to hydrogen and to anchor stability models. Data correlations, performance analysis, stability analyses, and key stability margin enhancement parameters are discussed.

Experimental Results of Integrated Refrigeration and Storage System Testing

NASA Technical Reports Server (NTRS)

Notardonato, W. U.; Johnson, W. L.; Jumper, K.

2009-01-01

Launch operations engineers at the Kennedy Space Center have identified an Integrated Refrigeration and Storage system as a promising technology to reduce launch costs and enable advanced cryogenic operations. This system uses a close cycle Brayton refrigerator to remove energy from the stored cryogenic propellant. This allows for the potential of a zero loss storage and transfer system, as well and control of the state of the propellant through densification or re-liquefaction. However, the behavior of the fluid in this type of system is different than typical cryogenic behavior, and there will be a learning curve associated with its use. A 400 liter research cryostat has been designed, fabricated and delivered to KSC to test the thermo fluid behavior of liquid oxygen as energy is removed from the cryogen by a simulated DC cycle cryocooler. Results of the initial testing phase focusing on heat exchanger characterization and zero loss storage operations using liquid oxygen are presented in this paper. Future plans for testing of oxygen densification tests and oxygen liquefaction tests will also be discussed. KEYWORDS: Liquid Oxygen, Refrigeration, Storage

Advanced Model for Extreme Lift and Improved Aeroacoustics (AMELIA)

NASA Technical Reports Server (NTRS)

Lichtwardt, Jonathan; Paciano, Eric; Jameson, Tina; Fong, Robert; Marshall, David

2012-01-01

With the very recent advent of NASA's Environmentally Responsible Aviation Project (ERA), which is dedicated to designing aircraft that will reduce the impact of aviation on the environment, there is a need for research and development of methodologies to minimize fuel burn, emissions, and reduce community noise produced by regional airliners. ERA tackles airframe technology, propulsion technology, and vehicle systems integration to meet performance objectives in the time frame for the aircraft to be at a Technology Readiness Level (TRL) of 4-6 by the year of 2020 (deemed N+2). The proceeding project that investigated similar goals to ERA was NASA's Subsonic Fixed Wing (SFW). SFW focused on conducting research to improve prediction methods and technologies that will produce lower noise, lower emissions, and higher performing subsonic aircraft for the Next Generation Air Transportation System. The work provided in this investigation was a NASA Research Announcement (NRA) contract #NNL07AA55C funded by Subsonic Fixed Wing. The project started in 2007 with a specific goal of conducting a large-scale wind tunnel test along with the development of new and improved predictive codes for the advanced powered-lift concepts. Many of the predictive codes were incorporated to refine the wind tunnel model outer mold line design. The large scale wind tunnel test goal was to investigate powered lift technologies and provide an experimental database to validate current and future modeling techniques. Powered-lift concepts investigated were Circulation Control (CC) wing in conjunction with over-the-wing mounted engines to entrain the exhaust to further increase the lift generated by CC technologies alone. The NRA was a five-year effort; during the first year the objective was to select and refine CESTOL concepts and then to complete a preliminary design of a large-scale wind tunnel model for the large scale test. During the second, third, and fourth years the large-scale wind tunnel model design would be completed, manufactured, and calibrated. During the fifth year the large scale wind tunnel test was conducted. This technical memo will describe all phases of the Advanced Model for Extreme Lift and Improved Aeroacoustics (AMELIA) project and provide a brief summary of the background and modeling efforts involved in the NRA. The conceptual designs considered for this project and the decision process for the selected configuration adapted for a wind tunnel model will be briefly discussed. The internal configuration of AMELIA, and the internal measurements chosen in order to satisfy the requirements of obtaining a database of experimental data to be used for future computational model validations. The external experimental techniques that were employed during the test, along with the large-scale wind tunnel test facility are covered in great detail. Experimental measurements in the database include forces and moments, and surface pressure distributions, local skin friction measurements, boundary and shear layer velocity profiles, far-field acoustic data and noise signatures from turbofan propulsion simulators. Results and discussion of the circulation control performance, over-the-wing mounted engines, and the combined performance are also discussed in great detail.

Program Monitoring with LTL in EAGLE

NASA Technical Reports Server (NTRS)

Barringer, Howard; Goldberg, Allen; Havelund, Klaus; Sen, Koushik

2004-01-01

We briefly present a rule-based framework called EAGLE, shown to be capable of defining and implementing finite trace monitoring logics, including future and past time temporal logic, extended regular expressions, real-time and metric temporal logics (MTL), interval logics, forms of quantified temporal logics, and so on. In this paper we focus on a linear temporal logic (LTL) specialization of EAGLE. For an initial formula of size m, we establish upper bounds of O(m(sup 2)2(sup m)log m) and O(m(sup 4)2(sup 2m)log(sup 2) m) for the space and time complexity, respectively, of single step evaluation over an input trace. This bound is close to the lower bound O(2(sup square root m) for future-time LTL presented. EAGLE has been successfully used, in both LTL and metric LTL forms, to test a real-time controller of an experimental NASA planetary rover.

HSV-2 Vaccine: Current Status and Insight into Factors for Developing an Efficient Vaccine

PubMed Central

Zhu, Xiao-Peng; Muhammad, Zaka S.; Wang, Jian-Guang; Lin, Wu; Guo, Shi-Kun; Zhang, Wei

2014-01-01

Herpes simplex virus type 2 (HSV-2), a globally sexually transmitted virus, and also one of the main causes of genital ulcer diseases, increases susceptibility to HIV-1. Effective vaccines to prevent HSV-2 infection are not yet available, but are currently being developed. To facilitate this process, the latest progress in development of these vaccines is reviewed in this paper. A summary of the most promising HSV-2 vaccines tested in animals in the last five years is presented, including the main factors, and new ideas for developing an effective vaccine from animal experiments and human clinical trials. Experimental results indicate that future HSV-2 vaccines may depend on a strategy that targets mucosal immunity. Furthermore, estradiol, which increases the effectiveness of vaccines, may be considered as an adjuvant. Therefore, this review is expected to provide possible strategies for development of future HSV-2 vaccines. PMID:24469503

Experimental quantum teleportation over a high-loss free-space channel.

PubMed

Ma, Xiao-song; Kropatschek, Sebastian; Naylor, William; Scheidl, Thomas; Kofler, Johannes; Herbst, Thomas; Zeilinger, Anton; Ursin, Rupert

2012-10-08

We present a high-fidelity quantum teleportation experiment over a high-loss free-space channel between two laboratories. We teleported six states of three mutually unbiased bases and obtained an average state fidelity of 0.82(1), well beyond the classical limit of 2/3. With the obtained data, we tomographically reconstructed the process matrices of quantum teleportation. The free-space channel attenuation of 31 dB corresponds to the estimated attenuation regime for a down-link from a low-earth-orbit satellite to a ground station. We also discussed various important technical issues for future experiments, including the dark counts of single-photon detectors, coincidence-window width etc. Our experiment tested the limit of performing quantum teleportation with state-of-the-art resources. It is an important step towards future satellite-based quantum teleportation and paves the way for establishing a worldwide quantum communication network.

Artificial gravity studies and design considerations for Space Station centrifuges

NASA Technical Reports Server (NTRS)

Halstead, T. W.; Brown, A. H.; Fuller, C. A.; Oyama, J.

1984-01-01

The requirements to and capabilities of a Space Station biological facility centrifuge are discussed on the basis of an assessment of the objectives and subjects of future microgravity biological experiments. It is argued that the facility should be capable of both acute and extended chronic exposure of test subjects and biological materials to altered-g loading. In addition, the experimental approaches and equipment for microgravity studies on a Space Station are outlined. Finally, the engineering requirements of such a centrifuge are examined, with consideration of radial gravity gradients, size, and physical access to animals.

Real-time Shakemap implementation in Austria

NASA Astrophysics Data System (ADS)

Weginger, Stefan; Jia, Yan; Papi Isaba, Maria; Horn, Nikolaus

2017-04-01

ShakeMaps provide near-real-time maps of ground motion and shaking intensity following significant earthquakes. They are automatically generated within a few minutes after occurrence of an earthquake. We tested and included the USGS ShakeMap 4.0 (experimental code) based on python in the Antelope real-time system with local modified GMPE and Site Effects based on the conditions in Austria. The ShakeMaps are provided in terms of Intensity, PGA, PGV and PSA. Future presentation of ShakeMap contour lines and Ground Motion Parameter with interactive maps and data exchange over Web-Services are shown.

Behavioral and neural representation of emotional facial expressions across the lifespan

PubMed Central

Somerville, Leah H.; Fani, Negar; McClure-Tone, Erin B.

2011-01-01

Humans’ experience of emotion and comprehension of affective cues varies substantially across the lifespan. Work in cognitive and affective neuroscience has begun to characterize behavioral and neural responses to emotional cues that systematically change with age. This review examines work to date characterizing the maturation of facial expression comprehension, and dynamic changes in amygdala recruitment from early childhood through late adulthood while viewing facial expressions of emotion. Recent neuroimaging work has tested amygdala and prefrontal engagement in experimental paradigms mimicking real aspects of social interactions, which we highlight briefly, along with considerations for future research. PMID:21516541

Ejected particle size measurement using Mie scattering in high explosive driven shockwave experiments

DOE PAGES

Monfared, Shabnam Khalighi; Buttler, William Tillman; Frayer, Daniel K.; ...

2015-06-11

In this paper, we report on the development of a diagnostic to provide constraints on the size of particles ejected from shocked metallic surfaces. The diagnostic is based on measurements of the intensity of laser light transmitted through a cloud of ejected particles as well as the angular distribution of scattered light, and the analysis of the resulting data is done using the Mie solution. Finally, we describe static experiments to test our experimental apparatus and present initial results of dynamic experiments on Sn targets. Improvements for future experiments are briefly discussed.

In vitro and in vivo studies on laser-activated gold nanorods for applications in photothermal therapies

NASA Astrophysics Data System (ADS)

Pini, Roberto; Ratto, Fulvio; Matteini, Paolo; Centi, Sonia; Rossi, Francesca

2010-04-01

We review our experimental studies on near infrared laser-activated gold nanoparticles in the direct welding of connective tissues. In particular, we discuss the use of gold nanorods excited by diode laser radiation at 810 nm to mediate functional photothermal effects and weld eye's lens capsules and arteries. The preparation of biopolymeric matrices including gold nanorods is described as well, together with preliminary tests for their application in the closure of wounds in vessels and tendons. Finally we mention future perspectives on the use of these nanoparticles for applications in the therapy of cancer.

A systematic study of mass spectra and strong decay of strange mesons

NASA Astrophysics Data System (ADS)

Pang, Cheng-Qun; Wang, Jun-Zhang; Liu, Xiang; Matsuki, Takayuki

2017-12-01

The mass spectrum of the kaon family is analyzed by the modified Godfrey-Isgur model with a color screening effect approximating the kaon as a heavy-light meson system. This analysis gives us the structure and possible assignments of the observed kaon candidates, which can be tested by comparing the theoretical results of their two-body strong decays with the experimental data. Additionally, prediction of some partial decay widths is made on the kaons still missing in experiment. This study is crucial to establishing the kaon family and searching for their higher excitations in the future.

Intense beams at the micron level for the Next Linear Collider

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

Seeman, J.T.

1991-08-01

High brightness beams with sub-micron dimensions are needed to produce a high luminosity for electron-positron collisions in the Next Linear Collider (NLC). To generate these small beam sizes, a large number of issues dealing with intense beams have to be resolved. Over the past few years many have been successfully addressed but most need experimental verification. Some of these issues are beam dynamics, emittance control, instrumentation, collimation, and beam-beam interactions. Recently, the Stanford Linear Collider (SLC) has proven the viability of linear collider technology and is an excellent test facility for future linear collider studies.

Rotating black hole solutions in relativistic analogue gravity

NASA Astrophysics Data System (ADS)

Giacomelli, Luca; Liberati, Stefano

2017-09-01

Simulation and experimental realization of acoustic black holes in analogue gravity systems have lead to a novel understanding of relevant phenomena such as Hawking radiation or superradiance. We explore here the possibility of using relativistic systems for simulating rotating black hole solutions and possibly get an acoustic analogue of a Kerr black hole. In doing so, we demonstrate a precise relation between nonrelativistic and relativistic solutions and provide a new class of vortex solutions for relativistic systems. Such solutions might be used in the future as a test bed in numerical simulations as well as concrete experiments.

Neural network analysis of Charpy transition temperature of irradiated low-activation martensitic steels

NASA Astrophysics Data System (ADS)

Cottrell, G. A.; Kemp, R.; Bhadeshia, H. K. D. H.; Odette, G. R.; Yamamoto, T.

2007-08-01

We have constructed a Bayesian neural network model that predicts the change, due to neutron irradiation, of the Charpy ductile-brittle transition temperature (ΔDBTT) of low-activation martensitic steels given a set of multi-dimensional published data with doses <100 displacements per atom (dpa). Results show the high significance of irradiation temperature and (dpa) 1/2 in determining ΔDBTT. Sparse data regions were identified by the size of the modelling uncertainties, indicating areas where further experimental data are needed. The method has promise for selecting and ranking experiments on future irradiation materials test facilities.

Documentation of Two- and Three-Dimensional Hypersonic Shock Wave/Turbulent Boundary Layer Interaction Flows

NASA Technical Reports Server (NTRS)

Kussoy, Marvin I.; Horstman, Clifford C.

1989-01-01

Experimental data for a series of two- and three-dimensional shock wave/turbulent boundary layer interaction flows at Mach 7 are presented. Test bodies, composed of simple geometric shapes, were designed to generate flows with varying degrees of pressure gradient, boundary-layer separation, and turning angle. The data include surface-pressure and heat-transfer distributions as well as limited mean-flow-field surveys in both the undisturbed and the interaction regimes. The data are presented in a convenient form for use in validating existing or future computational models of these generic hypersonic flows.

Pilot Preference, Compliance, and Performance With an Airborne Conflict Management Toolset

NASA Technical Reports Server (NTRS)

Doble, Nathan A.; Barhydt, Richard; Krishnamurthy, Karthik

2005-01-01

A human-in-the-loop experiment was conducted at the NASA Ames and Langley Research Centers, investigating the En Route Free Maneuvering component of a future air traffic management concept termed Distributed Air/Ground Traffic Management (DAG-TM). NASA Langley test subject pilots used the Autonomous Operations Planner (AOP) airborne toolset to detect and resolve traffic conflicts, interacting with subject pilots and air traffic controllers at NASA Ames. Experimental results are presented, focusing on conflict resolution maneuver choices, AOP resolution guidance acceptability, and performance metrics. Based on these results, suggestions are made to further improve the AOP interface and functionality.

In vivo detection of hemoglobin oxygen saturation and carboxyhemoglobin saturation with multiwavelength photoacoustic microscopy.

PubMed

Chen, Zhongjiang; Yang, Sihua; Xing, Da

2012-08-15

A method for noninvasively detecting hemoglobin oxygen saturation (SO2) and carboxyhemoglobin saturation (SCO) in subcutaneous microvasculature with multiwavelength photoacoustic microscopy is presented. Blood samples mixed with different concentrations of carboxyhemoglobin were used to test the feasibility and accuracy of photoacoustic microscopy compared with the blood-gas analyzer. Moreover, fixed-point detection of SO2 and SCO in mouse ear was obtained, and the changes from normoxia to carbon monoxide hypoxia were dynamically monitored in vivo. Experimental results demonstrate that multiwavelength photoacoustic microscopy can detect SO2 and SCO, which has future potential clinical applications.

Effect of a supportive-educative nursing intervention on older adults' perceptions of self-care after a stroke.

PubMed

Folden, S L

1993-01-01

The purpose of this study was to test the effects of an individually focused, guided decision-making intervention on individuals' perception of self-care ability following a stroke. A convenience sample of 68 individuals participating in four stroke rehabilitation programs in southeast Florida participated in the study. A quasi-experimental design using a pretest and a posttest was implemented. Findings indicated the potential effectiveness of this intervention in significantly increasing individuals' perceptions of their self-care ability after a stroke. Implications for practice and future research are discussed.

Optimization of Hyalella azteca IQ Toxicity Test{trademark} for prediction of 28-day sediment toxicity tests

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

Novotny, A.N.; Ezzard, C.L.; Douglas, W.S.

1995-12-31

The IQ Toxicity Test, which is a rapid screening toxicity test consisting of the observation of in-vivo inhibition of an enzymatic process using a fluorescent substrate, has proven successful for the determination of 24 and 48-hour EC50`s of D. magna, C. dubia, D. pulex and M. bahia. The application of this concept to utilize the freshwater amphipod Hyalella azteca may be an excellent way in which to reduce the standard 28-day chronic sediment toxicity test to possibly one hour`s time. This study incorporates an additive experimental design to explore the effects of and interactions between five specific variables: size ofmore » the amphipod, exposure time to the toxicant, concentration of substrate, exposure time to the substrate, and length of time starved prior to testing. The results of the IQ toxicity test were compared to those of a 28-day chronic sediment toxicity test. Preliminary data indicate that there is an optimal combination of these variables which results in a concise, reproducible toxicity test for use with Hyalella azteca, and would potentially be applicable to other freshwater amphipods in the future.« less

Future directions for H sub x O sub y detection, executive summary

NASA Technical Reports Server (NTRS)

1986-01-01

New methods for the measurement of OH radicals were assessed as were currently available and possible future methods for the other H sub x O sub y species, HO2 and H2O2. The workshop participants were invited from different groups: modelers of atmospheric photochemistry, experimentalists measuring H sub x O y species with laser and nonlaser methods, and chemists and physicists familiar with such experiments but not involved in atmospheric monitoring. There were three major conclusions from the workshop concerning the OH radical. First, it was felt that local measurements made by laser techniques would be ready within 2 or 3 years to furnish reliable measurements at the level of 1,000,000 cu. cm. Second, measurements at this level of sensitivity and with attainable levels of precision could indeed be used to make useful and interesting tests of the fast photochemistry of the troposphere. It is important, however, that the measurements be carefully designed, with respect to spatial and temporal averaging, if there is to be a meaningful comparison between results from two experimental methods or a measurement and a model. Third, nonlocal measurements using released reactants and tracers would also be very useful. These could be made on a regional or global basis, although they still require experimental design including choice of compounds.

The Influence of Social Networking Photos on Social Norms and Sexual Health Behaviors

PubMed Central

Jordan, Alexander H.

2013-01-01

Abstract Two studies tested whether online social networking technologies influence health behavioral social norms, and in turn, personal health behavioral intentions. In Study 1, experimental participants browsed peers' Facebook photos on a college network with a low prevalence of sexually suggestive content. Participants estimated the percentage of their peers who have sex without condoms, and rated their own future intentions to use condoms. Experimental participants, compared to controls who did not view photos, estimated that a larger percentage of their peers use condoms, and indicated a greater intention to use condoms themselves in the future. In Study 2, participants were randomly assigned to view sexually suggestive or nonsexually suggestive Facebook photos, and responded to sexual risk behavioral questions. Compared to participants viewing nonsuggestive photos, those who viewed sexually suggestive Facebook photos estimated that a larger percentage of their peers have unprotected sexual intercourse and sex with strangers and were more likely to report that they themselves would engage in these behaviors. Thus, online social networks can influence perceptions of the peer prevalence of sexual risk behaviors, and can influence users' own intentions with regard to such behaviors. These studies suggest the potential power of social networks to affect health behaviors by altering perceptions of peer norms. PMID:23438268

Development of Crystallizer for Advanced Aqueous Reprocessing Process

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

Tadahiro Washiya; Atsuhiro Shibata; Toshiaki Kikuchi

2006-07-01

Crystallization is one of the remarkable technologies for future fuel reprocessing process that has safety and economical advantages. Japan Atomic Energy Agency (JAEA) (former Japan Nuclear Cycle Development Institute), Mitsubishi Material Corporation and Saitama University have been developing the crystallization process. In previous study, we carried out experimental studies with uranium, MOX and spent fuel conditions, and flowsheet analysis was considered. In association with these studies, an innovative continuous crystallizer and its system was developed to ensure high process performance. From the design study, an annular type continuous crystallizer was selected as the most promising design, and performance was confirmedmore » by small-scale test and engineering scale demonstration at uranium crystallization conditions. In this paper, the design study and the demonstration test results are described. (authors)« less

Development of a Promising Fish Model (Oryzias melastigma) for Assessing Multiple Responses to Stresses in the Marine Environment

PubMed Central

Dong, Sijun; Kang, Mei; Wu, Xinlong; Ye, Ting

2014-01-01

With the increasing number of contaminants in the marine environment, various experimental organisms have been “taken into labs” by investigators to find the most suitable environmentally relevant models for toxicity testing. The marine medaka, Oryzias melastigma, has a number of advantages that make it a prime candidate for these tests. Recently, many studies have been conducted on marine medaka, especially in terms of their physiological, biochemical, and molecular responses after exposure to contaminants and other environmental stressors. This review provides a literature survey highlighting the steady increase of ecotoxicological research on marine medaka, summarizes the advantages of using O. melastigma as a tool for toxicological research, and promotes the utilization of this organism in future studies. PMID:24724087

Control of stacking loads in final waste disposal according to the borehole technique

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

Feuser, W.; Barnert, E.; Vijgen, H.

1996-12-01

The semihydrostatic model has been developed in order to assess the mechanical toads acting on heat-generating ILW(Q) and HTGR fuel element waste packages to be emplaced in vertical boreholes according to the borehole technique in underground rock salt formations. For the experimental validation of the theory, laboratory test stands reduced in scale are set up to simulate the bottom section of a repository borehole. A comparison of the measurement results with the data computed by the model, a correlation between the test stand results, and a systematic determination of material-typical crushed salt parameters in a separate research project will servemore » to derive a set of characteristic equations enabling a description of real conditions in a future repository.« less

Angular response calibration of the burst and transient source experiment

NASA Technical Reports Server (NTRS)

Lestrade, John Patrick

1988-01-01

The Gamma Ray Observatory includes four experiments designed to observe the gamma-ray universe. Laboratory measurements to test the response the Burst and Transient Source Experiment (BATSE) modules to gamma-ray sources that are non-axial were recently completed. The results of these observations are necessary for the correct interpretation of BATSE data obtained after it is put in Earth orbit. The launch is planned for March, 1900. Preliminary analyses of these test data show the presence of a radial dependence to the detector's light collection efficiency. It is proposed to evaluate the importance of this radial response, analyze future experimental data to derive the actual functional dependence on radius, and calculate the net effect on the output spectrum as a function of the angle of incidence.

Interferometer density measurements of a high-velocity plasmoid

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

Case, A.; Messer, S.; Bomgardner, R.

2010-05-15

The plasmoid produced by a half-scale contoured gap coaxial plasma accelerator using ablative polyethylene capillary plasma injectors is measured using a quadrature heterodyne HeNe interferometer. The plasmoid is found to have a sharp rise in density at the leading edge, with a gradual falloff after the peak density. For this early test series, an average bulk density of 5x10{sup 14} cm{sup -3} is observed, with densities up to 8x10{sup 14} cm{sup -3} seen on some shots. Although plasmoid mass is only about 58 mug due to the low current and injected mass used in these tests, good shot-to-shot repeatability ismore » attained making analysis relatively straightforward, thus providing a solid foundation for interpreting future experimental results.« less

Dynamic Impact Testing and Model Development in Support of NASA's Advanced Composites Program

NASA Technical Reports Server (NTRS)

Melis, Matthew E.; Pereira, J. Michael; Goldberg, Robert; Rassaian, Mostafa

2018-01-01

The purpose of this paper is to provide an executive overview of the HEDI effort for NASA's Advanced Composites Program and establish the foundation for the remaining papers to follow in the 2018 SciTech special session NASA ACC High Energy Dynamic Impact. The paper summarizes the work done for the Advanced Composites Program to advance our understanding of the behavior of composite materials during high energy impact events and to advance the ability of analytical tools to provide predictive simulations. The experimental program carried out at GRC is summarized and a status on the current development state for MAT213 will be provided. Future work will be discussed as the HEDI effort transitions from fundamental analysis and testing to investigating sub-component structural concept response to impact events.

Cyclic Cryogenic Thermal-Mechanical Testing of an X-33/RLV Liquid Oxygen Tank Concept

NASA Technical Reports Server (NTRS)

Rivers, H. Kevin

1999-01-01

An important step in developing a cost-effective, reusable, launch vehicle is the development of durable, lightweight, insulated, cryogenic propellant tanks. Current cryogenic tanks are expendable so most of the existing technology is not directly applicable to future launch vehicles. As part of the X-33/Reusable Launch Vehicle (RLV) Program, an experimental apparatus developed at the NASA Langley Research Center for evaluating the effects of combined, cyclic, thermal and mechanical loading on cryogenic tank concepts was used to evaluate cryogenic propellant tank concepts for Lockheed-Martin Michoud Space Systems. An aluminum-lithium (Al 2195) liquid oxygen tank concept, insulated with SS-1171 and PDL-1034 cryogenic insulation, is tested under simulated mission conditions, and the results of those tests are reported. The tests consists of twenty-five simulated Launch/Abort missions and twenty-five simulated flight missions with temperatures ranging from -320 F to 350 F and a maximum mechanical load of 71,300 lb. in tension.

Simulation and experiment for the inspection of stainless steel bolts in servicing using an ultrasonic phased array

NASA Astrophysics Data System (ADS)

Chen, Jinzhong; He, Renyang; Kang, Xiaowei; Yang, Xuyun

2015-10-01

The non-destructive testing of small-sized (M12-M20) stainless steel bolts in servicing is always a technical problem. This article focuses on the simulation and experimental research of stainless steel bolts with an artificial defect reflector using ultrasonic phased array inspection. Based on the observation of the sound field distribution of stainless steel bolts in ultrasonic phased array as well as simulation modelling and analysis of the phased array probes' detection effects with various defect sizes, different artificial defect reflectors of M16 stainless steel bolts are machined in reference to the simulation results. Next, those bolts are tested using a 10-wafer phased array probe with 5 MHz. The test results finally prove that ultrasonic phased array can detect 1-mm cracks in diameter with different depths of M16 stainless steel bolts and a metal loss of Φ1 mm of through-hole bolts, which provides technical support for future non-destructive testing of stainless steel bolts in servicing.

3-D Printed Ultem 9085 Testing and Analysis

NASA Technical Reports Server (NTRS)

Aguilar, Daniel; Christensen, Sean; Fox, Emmet J.

2015-01-01

The purpose of this document is to analyze the mechanical properties of 3-D printed Ultem 9085. This document will focus on the capabilities, limitations, and complexities of 3D printing in general, and explain the methods by which this material is tested. Because 3-D printing is a relatively new process that offers an innovative means to produce hardware, it is important that the aerospace community understands its current advantages and limitations, so that future endeavors involving 3-D printing may be completely safe. This document encompasses three main sections: a Slosh damage assessment, a destructive test of 3-D printed Ultem 9085 samples, and a test to verify simulation for the 3-D printed SDP (SPHERES Docking Port). Described below, 'Slosh' and 'SDP' refer to two experiments that are built using Ultem 9085 for use with the SPHERES (Synchronized Position Hold, Engage, Reorient, Experimental Satellites) program onboard the International Space Station (ISS) [16]. The SPHERES Facility is managed out of the National Aeronautics and Space Administration (NASA) Ames Research Center in California.

Shear compression testing of glass-fibre steel specimens after 4K reactor irradiation: Present status and facility upgrade

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

Gerstenberg, H.; Kraehling, E.; Katheder, H.

1997-06-01

The shear strengths of various fibre reinforced resins being promising candidate insulators for superconducting coils to be used tinder a strong radiation load, e.g. in future fusion reactors were investigated prior and subsequent to reactor in-core irradiation at liquid helium temperature. A large number of sandwich-like (steel-bonded insulation-steel) specimens representing a widespread variety of materials and preparation techniques was exposed to irradiation doses of up to 5 x 10{sup 7} Gy in form of fast neutrons and {gamma}-radiation. In a systematic study several experimental parameters including irradiation dose, postirradiation storage temperature and measuring temperature were varied before the determination ofmore » the ultimate shear strength. The results obtained from the different tested materials are compared. In addition an upgrade of the in-situ test rig installed at the Munich research reactor is presented, which allows combined shear/compression loading of low temperature irradiated specimens and provides a doubling of the testing rate.« less

Recommendation of ruthenium source for sludge batch flowsheet studies

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

Woodham, W.

Included herein is a preliminary analysis of previously-generated data from sludge batches 7a, 7b, 8, and 9 sludge simulant and real-waste testing, performed to recommend a form of ruthenium for future sludge batch simulant testing under the nitric-formic flowsheet. Focus is given to reactions present in the Sludge Receipt and Adjustment Tank cycle, given that this cycle historically produces the most changes in chemical composition during Chemical Process Cell processing. Data is presented and analyzed for several runs performed under the nitric-formic flowsheet, with consideration given to effects on the production of hydrogen gas, nitrous oxide gas, consumption of formate,more » conversion of nitrite to nitrate, and the removal and recovery of mercury during processing. Additionally, a brief discussion is given to the effect of ruthenium source selection under the nitric-glycolic flowsheet. An analysis of data generated from scaled demonstration testing, sludge batch 9 qualification testing, and antifoam degradation testing under the nitric-glycolic flowsheet is presented. Experimental parameters of interest under the nitric-glycolic flowsheet include N2O production, glycolate destruction, conversion of glycolate to formate and oxalate, and the conversion of nitrite to nitrate. To date, the number of real-waste experiments that have been performed under the nitric-glycolic flowsheet is insufficient to provide a complete understanding of the effects of ruthenium source selection in simulant experiments with regard to fidelity to real-waste testing. Therefore, a determination of comparability between the two ruthenium sources as employed under the nitric-glycolic flowsheet is made based on available data in order to inform ruthenium source selection for future testing under the nitric-glycolic flowsheet.« less

Autonomous mobile robot research using the HERMIES-III robot

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

Pin, F.G.; Beckerman, M.; Spelt, P.F.

1989-01-01

This paper reports on the status and future directions in the research, development and experimental validation of intelligent control techniques for autonomous mobile robots using the HERMIES-III robot at the Center for Engineering Systems Advanced research (CESAR) at Oak Ridge National Laboratory (ORNL). HERMIES-III is the fourth robot in a series of increasingly more sophisticated and capable experimental test beds developed at CESAR. HERMIES-III is comprised of a battery powered, onmi-directional wheeled platform with a seven degree-of-freedom manipulator arm, video cameras, sonar range sensors, laser imaging scanner and a dual computer system containing up to 128 NCUBE nodes in hypercubemore » configuration. All electronics, sensors, computers, and communication equipment required for autonomous operation of HERMIES-III are located on board along with sufficient battery power for three to four hours of operation. The paper first provides a more detailed description of the HERMIES-III characteristics, focussing on the new areas of research and demonstration now possible at CESAR with this new test-bed. The initial experimental program is then described with emphasis placed on autonomous performance of human-scale tasks (e.g., valve manipulation, use of tools), integration of a dexterous manipulator and platform motion in geometrically complex environments, and effective use of multiple cooperating robots (HERMIES-IIB and HERMIES- III). The paper concludes with a discussion of the integration problems and safety considerations necessarily arising from the set-up of an experimental program involving human-scale, multi-autonomous mobile robots performance. 10 refs., 3 figs.« less

Model based multivariable controller for large scale compression stations. Design and experimental validation on the LHC 18KW cryorefrigerator

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

Bonne, François; Bonnay, Patrick; Alamir, Mazen

2014-01-29

In this paper, a multivariable model-based non-linear controller for Warm Compression Stations (WCS) is proposed. The strategy is to replace all the PID loops controlling the WCS with an optimally designed model-based multivariable loop. This new strategy leads to high stability and fast disturbance rejection such as those induced by a turbine or a compressor stop, a key-aspect in the case of large scale cryogenic refrigeration. The proposed control scheme can be used to have precise control of every pressure in normal operation or to stabilize and control the cryoplant under high variation of thermal loads (such as a pulsedmore » heat load expected to take place in future fusion reactors such as those expected in the cryogenic cooling systems of the International Thermonuclear Experimental Reactor ITER or the Japan Torus-60 Super Advanced fusion experiment JT-60SA). The paper details how to set the WCS model up to synthesize the Linear Quadratic Optimal feedback gain and how to use it. After preliminary tuning at CEA-Grenoble on the 400W@1.8K helium test facility, the controller has been implemented on a Schneider PLC and fully tested first on the CERN's real-time simulator. Then, it was experimentally validated on a real CERN cryoplant. The efficiency of the solution is experimentally assessed using a reasonable operating scenario of start and stop of compressors and cryogenic turbines. This work is partially supported through the European Fusion Development Agreement (EFDA) Goal Oriented Training Program, task agreement WP10-GOT-GIRO.« less

Model based multivariable controller for large scale compression stations. Design and experimental validation on the LHC 18KW cryorefrigerator

NASA Astrophysics Data System (ADS)

Bonne, François; Alamir, Mazen; Bonnay, Patrick; Bradu, Benjamin

2014-01-01

In this paper, a multivariable model-based non-linear controller for Warm Compression Stations (WCS) is proposed. The strategy is to replace all the PID loops controlling the WCS with an optimally designed model-based multivariable loop. This new strategy leads to high stability and fast disturbance rejection such as those induced by a turbine or a compressor stop, a key-aspect in the case of large scale cryogenic refrigeration. The proposed control scheme can be used to have precise control of every pressure in normal operation or to stabilize and control the cryoplant under high variation of thermal loads (such as a pulsed heat load expected to take place in future fusion reactors such as those expected in the cryogenic cooling systems of the International Thermonuclear Experimental Reactor ITER or the Japan Torus-60 Super Advanced fusion experiment JT-60SA). The paper details how to set the WCS model up to synthesize the Linear Quadratic Optimal feedback gain and how to use it. After preliminary tuning at CEA-Grenoble on the 400W@1.8K helium test facility, the controller has been implemented on a Schneider PLC and fully tested first on the CERN's real-time simulator. Then, it was experimentally validated on a real CERN cryoplant. The efficiency of the solution is experimentally assessed using a reasonable operating scenario of start and stop of compressors and cryogenic turbines. This work is partially supported through the European Fusion Development Agreement (EFDA) Goal Oriented Training Program, task agreement WP10-GOT-GIRO.

Intermediate Scale Laboratory Testing to Understand Mechanisms of Capillary and Dissolution Trapping during Injection and Post-Injection of CO 2 in Heterogeneous Geological Formations

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

Illangasekare, Tissa; Trevisan, Luca; Agartan, Elif

2015-03-31

Carbon Capture and Storage (CCS) represents a technology aimed to reduce atmospheric loading of CO 2 from power plants and heavy industries by injecting it into deep geological formations, such as saline aquifers. A number of trapping mechanisms contribute to effective and secure storage of the injected CO 2 in supercritical fluid phase (scCO 2) in the formation over the long term. The primary trapping mechanisms are structural, residual, dissolution and mineralization. Knowledge gaps exist on how the heterogeneity of the formation manifested at all scales from the pore to the site scales affects trapping and parameterization of contributing mechanismsmore » in models. An experimental and modeling study was conducted to fill these knowledge gaps. Experimental investigation of fundamental processes and mechanisms in field settings is not possible as it is not feasible to fully characterize the geologic heterogeneity at all relevant scales and gathering data on migration, trapping and dissolution of scCO 2. Laboratory experiments using scCO 2 under ambient conditions are also not feasible as it is technically challenging and cost prohibitive to develop large, two- or three-dimensional test systems with controlled high pressures to keep the scCO 2 as a liquid. Hence, an innovative approach that used surrogate fluids in place of scCO 2 and formation brine in multi-scale, synthetic aquifers test systems ranging in scales from centimeter to meter scale developed used. New modeling algorithms were developed to capture the processes controlled by the formation heterogeneity, and they were tested using the data from the laboratory test systems. The results and findings are expected to contribute toward better conceptual models, future improvements to DOE numerical codes, more accurate assessment of storage capacities, and optimized placement strategies. This report presents the experimental and modeling methods and research results.« less

Digital image compression for a 2f multiplexing optical setup

NASA Astrophysics Data System (ADS)

Vargas, J.; Amaya, D.; Rueda, E.

2016-07-01

In this work a virtual 2f multiplexing system was implemented in combination with digital image compression techniques and redundant information elimination. Depending on the image type to be multiplexed, a memory-usage saving of as much as 99% was obtained. The feasibility of the system was tested using three types of images, binary characters, QR codes, and grey level images. A multiplexing step was implemented digitally, while a demultiplexing step was implemented in a virtual 2f optical setup following real experimental parameters. To avoid cross-talk noise, each image was codified with a specially designed phase diffraction carrier that would allow the separation and relocation of the multiplexed images on the observation plane by simple light propagation. A description of the system is presented together with simulations that corroborate the method. The present work may allow future experimental implementations that will make use of all the parallel processing capabilities of optical systems.

Incremental wind tunnel testing of high lift systems

NASA Astrophysics Data System (ADS)

Victor, Pricop Mihai; Mircea, Boscoianu; Daniel-Eugeniu, Crunteanu

2016-06-01

Efficiency of trailing edge high lift systems is essential for long range future transport aircrafts evolving in the direction of laminar wings, because they have to compensate for the low performance of the leading edge devices. Modern high lift systems are subject of high performance requirements and constrained to simple actuation, combined with a reduced number of aerodynamic elements. Passive or active flow control is thus required for the performance enhancement. An experimental investigation of reduced kinematics flap combined with passive flow control took place in a low speed wind tunnel. The most important features of the experimental setup are the relatively large size, corresponding to a Reynolds number of about 2 Million, the sweep angle of 30 degrees corresponding to long range airliners with high sweep angle wings and the large number of flap settings and mechanical vortex generators. The model description, flap settings, methodology and results are presented.

Autogenic-Feedback Training (AFT) as a preventive method for space motion sickness: Background and experimental design

NASA Technical Reports Server (NTRS)

Cowings, Patricia S.; Toscano, William B.

1993-01-01

Finding an effective treatment for the motion sickness-like symptoms that occur in space has become a high priority for NASA. The background research is reviewed and the experimental design of a formal life sciences shuttle flight experiment designed to prevent space motion sickness in shuttle crew members is presented. This experiment utilizes a behavioral medicine approach to solving this problem. This method, Autogenic-Feedback Training (AFT), involves training subjects to voluntarily control several of their own physiological responses to environmental stressors. AFT has been used reliably to increase tolerance to motion sickness during ground-based tests in over 200 men and women under a variety of conditions that induce motion sickness, and preliminary evidence from space suggests that AFT may be an effective treatment for space motion sickness as well. Proposed changes to this experiment for future manifests are included.

STOL propulsion systems

NASA Technical Reports Server (NTRS)

Denington, R. J.; Koenig, R. W.; Vanco, M. R.; Sagerser, D. A.

1972-01-01

The selection and the characteristics of quiet, clean propulsion systems for STOL aircraft are discussed. Engines are evaluated for augmentor wing and externally blown flap STOL aircraft with the engines located both under and over the wings. Some supporting test data are presented. Optimum engines are selected based on achieving the performance, economic, acoustic, and pollution goals presently being considered for future STOL aircraft. The data and results presented were obtained from a number of contracted studies and some supporting NASA inhouse programs, most of which began in early 1972. The contracts include: (1) two aircraft and mission studies, (2) two propulsion system studies, (3) the experimental and analytic work on the augmentor wing, and (4) the experimental programs on Q-Fan. Engines are selected and discussed based on aircraft economics using the direct operating cost as the primary criterion. This cost includes the cost of the crew, fuel, aircraft, and engine maintenance and depreciation.

[Use of driving simulators in psychological research].

PubMed

Andysz, Aleksandra; Waszkowska, Małgorzata; Merecz, Dorota; Drabek, Marcin

2010-01-01

The history of simulators dates back to the first decades of the twentieth century. At the beginning they were used to train pilots, and eventually they were used in the automotive industry for testing the strength of new vehicles and ergonomic solutions. With time research institutions and technical universities from outside the automotive industry have become more and more interested in simulators. Attractiveness of simulators for researchers is based on a number of important factors: they create the possibility of modeling, control and repeatability of different experimental situations, reducing at the same time the impact of confounding factors. Simulators have a great potential for data collection and processing. What's more, they are safe and ecologic. These values make them almost an ideal research tool. The article presents a review of psychological studies with use of vehicle driving simulators. It also points to advantages and disadvantages of these devices and outlines the future prospects for experimental research.

Design and Performance Evaluation of an Electro-Hydraulic Camless Engine Valve Actuator for Future Vehicle Applications

PubMed Central

Nam, Kanghyun; Cho, Kwanghyun; Park, Sang-Shin; Choi, Seibum B.

2017-01-01

This paper details the new design and dynamic simulation of an electro-hydraulic camless engine valve actuator (EH-CEVA) and experimental verification with lift position sensors. In general, camless engine technologies have been known for improving fuel efficiency, enhancing power output, and reducing emissions of internal combustion engines. Electro-hydraulic valve actuators are used to eliminate the camshaft of an existing internal combustion engines and used to control the valve timing and valve duration independently. This paper presents novel electro-hydraulic actuator design, dynamic simulations, and analysis based on design specifications required to satisfy the operation performances. An EH-CEVA has initially been designed and modeled by means of a powerful hydraulic simulation software, AMESim, which is useful for the dynamic simulations and analysis of hydraulic systems. Fundamental functions and performances of the EH-CEVA have been validated through comparisons with experimental results obtained in a prototype test bench. PMID:29258270

Wet Lab Accelerator: A Web-Based Application Democratizing Laboratory Automation for Synthetic Biology.

PubMed

Bates, Maxwell; Berliner, Aaron J; Lachoff, Joe; Jaschke, Paul R; Groban, Eli S

2017-01-20

Wet Lab Accelerator (WLA) is a cloud-based tool that allows a scientist to conduct biology via robotic control without the need for any programming knowledge. A drag and drop interface provides a convenient and user-friendly method of generating biological protocols. Graphically developed protocols are turned into programmatic instruction lists required to conduct experiments at the cloud laboratory Transcriptic. Prior to the development of WLA, biologists were required to write in a programming language called "Autoprotocol" in order to work with Transcriptic. WLA relies on a new abstraction layer we call "Omniprotocol" to convert the graphical experimental description into lower level Autoprotocol language, which then directs robots at Transcriptic. While WLA has only been tested at Transcriptic, the conversion of graphically laid out experimental steps into Autoprotocol is generic, allowing extension of WLA into other cloud laboratories in the future. WLA hopes to democratize biology by bringing automation to general biologists.

Experimental Measurements of Heat Transfer through a Lunar Regolith Simulant in a Vibro-Fluidized Reactor Oven

NASA Technical Reports Server (NTRS)

Nayagam, Vedha; Berger, Gordon M.; Sacksteder, Kurt R.; Paz, Aaron

2012-01-01

Extraction of mission consumable resources such as water and oxygen from the planetary environment provides valuable reduction in launch-mass and potentially extends the mission duration. Processing of lunar regolith for resource extraction necessarily involves heating and chemical reaction of solid material with processing gases. Vibrofluidization is known to produce effective mixing and control of flow within granular media. In this study we present experimental results for vibrofluidized heat transfer in lunar regolith simulants (JSC-1 and JSC-1A) heated up to 900 C. The results show that the simulant bed height has a significant influence on the vibration induced flow field and heat transfer rates. A taller bed height leads to a two-cell circulation pattern whereas a single-cell circulation was observed for a shorter height. Lessons learned from these test results should provide insight into efficient design of future robotic missions involving In-Situ Resource Utilization.

Design and Performance Evaluation of an Electro-Hydraulic Camless Engine Valve Actuator for Future Vehicle Applications.

PubMed

Nam, Kanghyun; Cho, Kwanghyun; Park, Sang-Shin; Choi, Seibum B

2017-12-18

This paper details the new design and dynamic simulation of an electro-hydraulic camless engine valve actuator (EH-CEVA) and experimental verification with lift position sensors. In general, camless engine technologies have been known for improving fuel efficiency, enhancing power output, and reducing emissions of internal combustion engines. Electro-hydraulic valve actuators are used to eliminate the camshaft of an existing internal combustion engines and used to control the valve timing and valve duration independently. This paper presents novel electro-hydraulic actuator design, dynamic simulations, and analysis based on design specifications required to satisfy the operation performances. An EH-CEVA has initially been designed and modeled by means of a powerful hydraulic simulation software, AMESim, which is useful for the dynamic simulations and analysis of hydraulic systems. Fundamental functions and performances of the EH-CEVA have been validated through comparisons with experimental results obtained in a prototype test bench.

Experimental demonstration of active vibration control for flexible structures

NASA Technical Reports Server (NTRS)

Phillips, Douglas J.; Hyland, David C.; Collins, Emmanuel G., Jr.

1990-01-01

Active vibration control of flexible structures for future space missions is addressed. Three experiments that successfully demonstrate control of flexible structures are described. The first is the pendulum experiment. The structure is a 5-m compound pendulum and was designed as an end-to-end test bed for a linear proof mass actuator and its supporting electronics. Experimental results are shown for a maximum-entropy/optimal-projection controller designed to achieve 5 percent damping in the first two pendulum modes. The second experiment was based upon the Harris Multi-Hex prototype experiment (MHPE) apparatus. This is a large optical reflector structure comprising a seven-panel array and supporting truss which typifies a number of generic characteristics of large space systems. The third experiment involved control design and implementation for the ACES structure at NASA Marshall Space Flight Center. The authors conclude with some remarks on the lessons learned from conducting these experiments.

Systems Biology-Driven Hypotheses Tested In Vivo: The Need to Advancing Molecular Imaging Tools.

PubMed

Verma, Garima; Palombo, Alessandro; Grigioni, Mauro; La Monaca, Morena; D'Avenio, Giuseppe

2018-01-01

Processing and interpretation of biological images may provide invaluable insights on complex, living systems because images capture the overall dynamics as a "whole." Therefore, "extraction" of key, quantitative morphological parameters could be, at least in principle, helpful in building a reliable systems biology approach in understanding living objects. Molecular imaging tools for system biology models have attained widespread usage in modern experimental laboratories. Here, we provide an overview on advances in the computational technology and different instrumentations focused on molecular image processing and analysis. Quantitative data analysis through various open source software and algorithmic protocols will provide a novel approach for modeling the experimental research program. Besides this, we also highlight the predictable future trends regarding methods for automatically analyzing biological data. Such tools will be very useful to understand the detailed biological and mathematical expressions under in-silico system biology processes with modeling properties.