Science.gov

Sample records for active chevron concept

  1. Testing of SMA-enabled Active Chevron Prototypes under Representative Flow Conditions

    NASA Technical Reports Server (NTRS)

    Turner, Travis L.; Cabell,Randolph H.; Cano, Roberto J.; Silcox, Richard J.

    2008-01-01

    Control of jet noise continues to be an important research topic. Exhaust-nozzle chevrons have been shown to reduce jet noise, but parametric effects are not well understood. Additionally, thrust loss due to chevrons at cruise suggests significant benefit from active chevrons. The focus of this study is development of an active chevron concept for the primary purpose of parametric studies for jet noise reduction in the laboratory and secondarily for technology development to leverage for full scale systems. The active chevron concept employed in this work consists of a laminated composite structure with embedded shape memory alloy (SMA) actuators, termed a SMA hybrid composite (SMAHC). SMA actuators are embedded on one side of the neutral axis of the structure such that thermal excitation, via joule heating, generates a moment and deflects the structure. The performance of two active chevron concepts is demonstrated in the presence of representative flow conditions. One of the concepts is shown to possess significant advantages for the proposed application and is selected for further development. Fabrication and design changes are described and shown to produce a chevron prototype that meets the performance objectives.

  2. Wet active chevron nozzle for controllable jet noise reduction

    NASA Technical Reports Server (NTRS)

    Thomas, Russell H. (Inventor); Kinzie, Kevin W. (Inventor)

    2011-01-01

    Disposed at or toward the trailing edge of one or more nozzles associated with a jet engine are injection ports which can selectively be made to discharge a water stream into a nozzle flow stream for the purpose of increasing turbulence in somewhat of a similar fashion as mechanically disposed chevrons have done in the known art. Unlike mechanically disposed chevrons of the known art, the fluid flow may be secured thereby increasing the engine efficiency. Various flow patterns, water pressures, orifice designs or other factors can be made operative to provide desired performance characteristics.

  3. Fluidic Chevrons for Jet Noise Reduction

    NASA Technical Reports Server (NTRS)

    Kinzie, Kevin; Henderson, Brenda; Whitmire, Julia

    2004-01-01

    Chevron mixing devices are used to reduce noise from commercial separate-flow turbofan engines. Mechanical chevron serrations at the nozzle trailing edge generate axial vorticity that enhances jet plume mixing and consequently reduces far-field noise. Fluidic chevrons generated with air injected near the nozzle trailing edge create a vorticity field similar to that of the mechanical chevrons and allow more flexibility in controlling acoustic and thrust performance than a passive mechanical design. In addition, the design of such a system has the future potential for actively controlling jet noise by pulsing or otherwise optimally distributing the injected air. Scale model jet noise experiments have been performed in the NASA Langley Low Speed Aeroacoustic Wind Tunnel to investigate the fluidic chevron concept. Acoustic data from different fluidic chevron designs are shown. Varying degrees of noise reduction are achieved depending on the injection pattern and injection flow conditions. CFD results were used to select design concepts that displayed axial vorticity growth similar to that associated with mechanical chevrons and qualitatively describe the air injection flow and the impact on acoustic performance.

  4. 33 CFR 147.825 - Chevron Genesis Spar safety zone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Chevron Genesis Spar safety zone... (CONTINUED) OUTER CONTINENTAL SHELF ACTIVITIES SAFETY ZONES § 147.825 Chevron Genesis Spar safety zone. (a) Description. The Chevron Genesis Spar, Green Canyon 205A (GC205A), is located at position 27°46′46.365″ N,...

  5. Design, fabrication, and testing of a SMA hybrid composite jet engine chevron

    NASA Astrophysics Data System (ADS)

    Turner, Travis L.; Cabell, Randolph H.; Cano, Roberto J.; Fleming, Gary A.

    2006-03-01

    Control of jet noise continues to be an important research topic. Exhaust nozzle chevrons have been shown to reduce jet noise, but parametric effects are not well understood. Additionally, thrust loss due to chevrons at cruise suggests significant benefit from deployable chevrons. The focus of this study is development of an active chevron concept for the primary purpose of parametric studies for jet noise reduction in the laboratory and technology development to leverage for full scale systems. The active chevron concept employed in this work consists of a laminated composite structure with embedded shape memory alloy (SMA) actuators, termed a SMA hybrid composite (SMAHC). The actuators are embedded on one side of the middle surface such that thermal excitation generates a moment and deflects the structure. A brief description of the chevron design is given followed by details of the fabrication approach. Results from bench top tests are presented and correlated with numerical predictions from a model for such structures that was recently implemented in MSC.Nastran and ABAQUS. Excellent performance and agreement with predictions is demonstrated. Results from tests in a representative flow environment are also presented. Excellent performance is again achieved for both open- and closed-loop tests, the latter demonstrating control to a specified immersion into the flow. The actuation authority and immersion performance is shown to be relatively insensitive to nozzle pressure ratio (NPR). Very repeatable immersion control with modest power requirements is demonstrated.

  6. Design, fabrication, and testing of a SMA hybrid composite jet engine chevron

    NASA Technical Reports Server (NTRS)

    Turner, Travis L.; Cabell, Randolph H.; Cano, Roberto J.; Fleming, Gary A.

    2006-01-01

    Control of jet noise continues to be an important research topic. Exhaust nozzle chevrons have been shown to reduce jet noise, but parametric effects are not well understood. Additionally, thrust loss due to chevrons at cruise suggests significant benefit from deployable chevrons. The focus of this study is development of an active chevron concept for the primary purpose of parametric studies for jet noise reduction in the laboratory and technology development to leverage for full scale systems. The active chevron concept employed in this work consists of a laminated composite structure with embedded shape memory alloy (SMA) actuators, termed a SMA hybrid composite (SMAHC). The actuators are embedded on one side of the middle surface such that thermal excitation generates a moment and deflects the structure. A brief description of the chevron design is given followed by details of the fabrication approach. Results from bench top tests are presented and correlated with numerical predictions from a model for such structures that was recently implemented in MSC.Nastran and ABAQUS. Excellent performance and agreement with predictions is demonstrated. Results from tests in a representative flow environment are also presented. Excellent performance is again achieved for both open- and closed-loop tests, the latter demonstrating control to a specified immersion into the flow. The actuation authority and immersion performance is shown to be relatively insensitive to nozzle pressure ratio (NPR). Very repeatable immersion control with modest power requirements is demonstrated.

  7. Sedimentology of coastal chevron deposits - tsunamigenic versus aeolian origin

    NASA Astrophysics Data System (ADS)

    Garcia Garcia, A.; Spiske, M.; Tsukamoto, S.; Schmidt, V.

    2012-12-01

    The genesis of v-shaped coastal chevrons is currently controversially discussed. So far, chevrons are only described regarding their morphology, but not in terms of their origin. Two possible origins of chevrons are proposed: both aeolian transport and tsunami inundation are discussed as depositing processes. We present initial results of a detailed sedimentological survey of Holocene coastal chevrons from the American and Australian west coasts. The chevrons were measured and levelled using a differential GPS system. Large scale internal structures were recorded by ground penetrating radar imaging. Trenches were dug for sampling and analyzing small scale internal structures. The sediment samples were used for the analysis of grain-size distributions, mineral composition and content of marine microorganisms. Additional samples were taken for optically stimulated luminescence (OSL) and radiocarbon dating. Furthermore, we took reference samples from beaches, cliffs and rivers, which could act as potential sediment sources for the surveyed chevrons. Tsunami deposits are commonly polymodal, exhibit a grain-size decrease and tend to show better sorting in landward direction. Such trends are not present in the surveyed chevrons. Most samples are well to moderately well sorted and unimodal. The OSL ages decrease in transport direction and indicate a long term generation process, such as dune migration, rather than a short term event like a tsunami. This fact is additionally underlined by land snails found in different stratigraphic levels within the Australian chevrons. Furthermore, the occurrence of intercalated soil horizons implies a change of stable and active migration phases. The initial results of this study point out to an aoelian origin of coastal chevrons and do not support the previously supposed thesis of a tsunamigenic origin.

  8. Smectic C chevrons in nanocylinders

    SciTech Connect

    Lefort, R. Morineau, D.; Jean, F.; Noirez, L.; Ndao, M.; Cerclier, C. V.

    2014-11-17

    The structure of an achiral smectic-C liquid crystal confined in nanocylinders with a planar surface anchoring is studied by small angle neutron scattering. We observe an invariant alignment of the nematic director with the pore axis, that promotes an original chevron structure with revolution symmetry.

  9. Parametric Testing of Chevrons on Single Flow Hot Jets

    NASA Technical Reports Server (NTRS)

    Bridges, James; Brown, Clifford A.

    2004-01-01

    A parametric family of chevron nozzles have been studied, looking for relationships between chevron geometric parameters, flow characteristics, and far-field noise. Both cold and hot conditions have been run at acoustic Mach number 0.9. Ten models have been tested, varying chevron count, penetration, length, and chevron symmetry. Four comparative studies were defined from these datasets which show: that chevron length is not a major impact on either flow or sound; that chevron penetration increases noise at high frequency and lowers it at low frequency, especially for low chevron counts; that chevron count is a strong player with good low frequency reductions being achieved with high chevron count without strong high frequency penalty; and that chevron asymmetry slightly reduces the impact of the chevron. Finally, it is shown that although the hot jets differ systematically from the cold one, the overall trends with chevron parameters is the same.

  10. Flight Test Results for Uniquely Tailored Propulsion-Airframe Aeroacoustic Chevrons: Community Noise

    NASA Technical Reports Server (NTRS)

    Nesbitt, Eric; Mengle, Vinod; Czech, Michael; Callendar, Bryan; Thomas, Russ

    2006-01-01

    The flow/acoustic environment around the jet exhaust of an engine when installed on an airplane, say, under the wing, is highly asymmetric due to the pylon, the wing and the high-lift devices. Recent scale model tests have shown that such Propulsion Airframe Aeroacoustic (PAA) interactions and the jet mixing noise can be reduced more than with conventional azimuthally uniform chevrons by uniquely tailoring the chevrons to produce enhanced mixing near the pylon. This paper describes the community noise results from a flight test on a large twin-engine airplane using this concept of azimuthally varying chevrons for engines installed under the wing. Results for two different nozzle configurations are described: azimuthally varying "PAA T-fan" chevrons on the fan nozzle with a baseline no-chevron core nozzle and a second with PAA T-fan chevrons with conventional azimuthally uniform chevrons on the core nozzle. We analyze these test results in comparison to the baseline no-chevron nozzle on both spectral and integrated power level bases. The study focuses on the peak jet noise reduction and the effects at high frequencies for typical take-off power settings. The noise reduction and the absolute noise levels are then compared to model scale results. The flight test results verify that the PAA T-fan nozzles in combination with standard core chevron nozzles can, indeed, give a reasonable amount of noise reduction at low frequencies without high-frequency lift during take-off conditions and hardly any impact on the cruise thrust coefficient.

  11. Industry. Pollution prevention: The Chevron story

    SciTech Connect

    Karras, G. )

    1989-10-01

    This article outlines the efforts of Chevron to control pollution in the San Francisco Bay area. The company worked on reducing the numbers and types of pollutants used in the petrochemical industry. By changing the raw materials used in production as well as altering the finished products, the Chevron refinery was able to significantly reduce the toxic metals in the Bay area.

  12. Changing Conceptions of Activation Energy.

    ERIC Educational Resources Information Center

    Pacey, Philip D.

    1981-01-01

    Provides background material which relates to the concept of activation energy, fundamental in the study of chemical kinetics. Compares the related concepts of the Arrhenius activation energy, the activation energy at absolute zero, the enthalpy of activation, and the threshold energy. (CS)

  13. Chevrons formation in laminar erosion

    NASA Astrophysics Data System (ADS)

    Devauchelle, Olivier; Josserand, Christophe; Lagree, Pierre-Yves; Zaleski, Stephane; Nguyen, Khanh-Dang; Malverti, Luce; Lajeunesse, Eric

    2007-11-01

    When eroded by laminar free-surface flows, granular substrates may generate a rich variety of natural patterns. Among them are dunes, similar to the ones observed by Charru and Hinch in a Couette cell (Charru F, Hinch EJ ; Ripple formation on a particle bed sheared by a viscous liquid. Part 1. Steady flow ; JOURNAL OF FLUID MECHANICS 550: 111-121 MAR 10 2006). Chevron-shaped instabilities as those found on the sea-shore, can also be observed, sometimes in competition against dunes formation. These were first pointed out by Daerr et al. when pulling a plate covered with granular material out of a bath of water (Daerr A, Lee P, Lanuza J, et al. ; Erosion patterns in a sediment layer ; PHYSICAL REVIEW E 67 (6): Art. No. 065201 Part 2 JUN 2003). Both instabilities can grow in laminar open-channel flows, an experimental set-up which is more easily controlled. The mechanisms leading to the formation of these patterns are investigated and compared. Whereas dunes formation requires vertical inertia effects, we show that chevrons may result from the non-linear evolution of bars instability, which may grow even in purely viscous flows.

  14. Marine construction. Chevron sets completion in record depth

    SciTech Connect

    Not Available

    1983-11-01

    The deepest well scheduled for production to date, Chevron's Montanazo D2 discovery offshore Spain, will be produced with a satellite facility. The well is in 2,474 ft of water and will be serviced with a remotely operated vehicle. Chevron favored the concept over several floating production schemes. The well will flow through two 4-in. flowlines up-slope for a distance of 5 miles to the Casablanca field platform, beginning in the summer of 1985. Tests over a period of 4 yr include no evidence of downslope pressure on the surface conductor, which could cause deflection problems in the well. The satellite Christmas tree will be capable of vertical entry and installed on a 16-3/4-in., 10,000-psi wellhead system. A crossover loop is included for pigging flowlines and for production through either of the flowlines. A remotely operated vehicle will be the primary tool for intervention and maintenance operations.

  15. Chevron formation of the zebrafish muscle segments

    PubMed Central

    Rost, Fabian; Eugster, Christina; Schröter, Christian; Oates, Andrew C.; Brusch, Lutz

    2014-01-01

    The muscle segments of fish have a folded shape, termed a chevron, which is thought to be optimal for the undulating body movements of swimming. However, the mechanism shaping the chevron during embryogenesis is not understood. Here, we used time-lapse microscopy of developing zebrafish embryos spanning the entire somitogenesis period to quantify the dynamics of chevron shape development. By comparing such time courses with the start of movements in wildtype zebrafish and analysing immobile mutants, we show that the previously implicated body movements do not play a role in chevron formation. Further, the monotonic increase of chevron angle along the anteroposterior axis revealed by our data constrains or rules out possible contributions by previously proposed mechanisms. In particular, we found that muscle pioneers are not required for chevron formation. We put forward a tension-and-resistance mechanism involving interactions between intra-segmental tension and segment boundaries. To evaluate this mechanism, we derived and analysed a mechanical model of a chain of contractile and resisting elements. The predictions of this model were verified by comparison with experimental data. Altogether, our results support the notion that a simple physical mechanism suffices to self-organize the observed spatiotemporal pattern in chevron formation. PMID:25267843

  16. Aeroacoustic Improvements to Fluidic Chevron Nozzles

    NASA Technical Reports Server (NTRS)

    Henderson, Brenda; Kinzie, Kevin; Whitmire, Julia; Abeysinghe, Amal

    2006-01-01

    Fluidic chevrons use injected air near the trailing edge of a nozzle to emulate mixing and jet noise reduction characteristics of mechanical chevrons. While previous investigations of "first generation" fluidic chevron nozzles showed only marginal improvements in effective perceived noise levels when compared to nozzles without injection, significant improvements in noise reduction characteristics were achieved through redesigned "second generation" nozzles on a bypass ratio 5 model system. The second-generation core nozzles had improved injection passage contours, external nozzle contour lines, and nozzle trailing edges. The new fluidic chevrons resulted in reduced overall sound pressure levels over that of the baseline nozzle for all observation angles. Injection ports with steep injection angles produced lower overall sound pressure levels than those produced by shallow injection angles. The reductions in overall sound pressure levels were the result of noise reductions at low frequencies. In contrast to the first-generation nozzles, only marginal increases in high frequency noise over that of the baseline nozzle were observed for the second-generation nozzles. The effective perceived noise levels of the new fluidic chevrons are shown to approach those of the core mechanical chevrons.

  17. Design, Fabrication, and Testing of SMA Enabled Adaptive Chevrons for Jet Noise Reduction

    NASA Technical Reports Server (NTRS)

    Turner, Travis L.; Buehrle, Ralph D.; Cano, Roberto J.; Fleming, Gary A.

    2004-01-01

    This study presents the status and results from an effort to design, fabricate, and test an adaptive jet engine chevron concept based upon embedding shape memory alloy (SMA) actuators in a composite laminate, termed a SMA hybrid composite (SMAHC). The approach for fabricating the adaptive SMAHC chevrons involves embedding prestrained Nitinol actuators on one side of the mid-plane of the composite laminate such that thermal excitation generates a thermal moment and deflects the structure. A glass-epoxy pre-preg/Nitinol ribbon material system and a vacuum hot press consolidation approach are employed. A versatile test system for control and measurement of the chevron deflection performance is described. Projection moire interferometry (PMI) is used for global deformation measurement and infrared (IR) thermography is used for 2-D temperature measurement and feedback control. A recently commercialized constitutive model for SMA and SMAHC materials is used in the finite element code ABAQUS to perform nonlinear static analysis of the chevron prototypes. Excellent agreement is achieved between the predicted and measured chevron deflection performance, thereby validating the design tool. Although the performance results presented in this paper fall short of the requirement, the concept is proven and an approach for achieving the performance objectives is evident.

  18. Chevron cutting: Experiment with new runway mixtures

    NASA Technical Reports Server (NTRS)

    Tyran, K. (Compiler)

    1978-01-01

    Chevron cutting is shown to occur in different forms depending on the type of tire and the rubber on the running surface. Hardest wear is shown by the main tires of the B-747. Four defects occurred, in the form of two rip separation and two breakouts of the running surface. Tires capped by Thompson are more affected than any of the other rubber-capping fabrics. For Thompson tires, Chevron Cutting is greatly reduced with a fiberglass-rubber mixture. For Goodyear tires, it is eliminated with spiral wrap rubbercapping; resistance to damages through cuts seems to be more positive for Goodyear tires. For Mader tires, the extent of Chevron Cutting is generally smaller than for Thompson cappings.

  19. Reducing Propulsion Airframe Aeroacoustic Interactions with Uniquely Tailored Chevrons. 2; Installed Nozzles

    NASA Technical Reports Server (NTRS)

    Mengle, Vinod G.; Elkoby, Ronen; Brusniak, Leon; Thomas, Russ H.

    2006-01-01

    Propulsion airframe aeroacoustic (PAA) interactions arise due to the manner in which an engine is installed on the airframe and lead to an asymmetry in the flow/acoustic environment, for example, for under-the-wing installations due to the pylon, the wing and the high-lift devices. In this work we study how we can affect these PAA interactions to reduce the overall jet-related installed noise by tailoring the chevron shapes on fan and core nozzles in a unique fashion to take advantage of this asymmetry. In part 1 of this trio of papers we introduced the concept of azimuthally varying chevrons (AVC) and showed how some types of AVCs can be more beneficial than the conventional chevrons when tested on "isolated" scaled nozzles inclusive of the pylon effect. In this paper, we continue to study the effect of installing these AVC nozzles under a typical scaled modern wing with high-lift devices placed in a free jet. The noise benefits of these installed nozzles, as well as their installation effects are systematically studied for several fan/core AVC combinations at typical take-off conditions with high bypass ratio. We show, for example, that the top-enhanced mixing T-fan AVC nozzle (with enhanced mixing near the pylon and less mixing away from it) when combined with conventional chevrons on the core nozzle is quieter than conventional chevrons on both nozzles, and hardly produces any high-frequency lift, just as in the isolated case; however, its installed nozzle benefit is less than its isolated nozzle benefit. This suppression of take-off noise benefit under installed conditions, compared to its isolated nozzle benefit, is seen for all other chevron nozzles. We show how these relative noise benefits are related to the relative installation effects of AVCs and baseline nozzles.

  20. Chevron folding patterns and heteroclinic orbits

    NASA Astrophysics Data System (ADS)

    Budd, Christopher J.; Chakhchoukh, Amine N.; Dodwell, Timothy J.; Kuske, Rachel

    2016-09-01

    We present a model of multilayer folding in which layers with bending stiffness EI are separated by a very stiff elastic medium of elasticity k2 and subject to a horizontal load P. By using a dynamical system analysis of the resulting fourth order equation, we show that as the end shortening per unit length E is increased, then if k2 is large there is a smooth transition from small amplitude sinusoidal solutions at moderate values of P to larger amplitude chevron folds, with straight limbs separated by regions of high curvature when P is large. The chevron solutions take the form of near heteroclinic connections in the phase-plane. By means of this analysis, values for P and the slope of the limbs are calculated in terms of E and k2.

  1. Concepts in Activities and Discourses

    ERIC Educational Resources Information Center

    Greeno, James G.

    2012-01-01

    The articles in this special issue make valuable contributions toward a scientific understanding of concepts that is broader than the traditional view that has focused on categorizing by individuals. I propose considering concepts for categorization as a special case of concepts. At their clearest, they can be referred to as "formal concepts," or…

  2. Compliance measurements of chevron notched four point bend specimen

    NASA Technical Reports Server (NTRS)

    Calomino, Anthony; Bubsey, Raymond; Ghosn, Louis J.

    1994-01-01

    The experimental stress intensity factors for various chevron notched four point bend specimens are presented. The experimental compliance is verified using the analytical solution for a straight through crack four point bend specimen and the boundary integral equation method for one chevron geometry. Excellent agreement is obtained between the experimental and analytical results. In this report, stress intensity factors, loading displacements and crack mouth opening displacements are reported for different crack lengths and different chevron geometries, under four point bend loading condition.

  3. A review of chevron-notched fracture specimens

    NASA Technical Reports Server (NTRS)

    Newman, J. C., Jr.

    1984-01-01

    The historical development of chevron notched fracture specimens is reviewed. Stress intensity factors and load line displacement solutions proposed for some of these specimens are compared. The original bend bar configurations up to the present day short rod and bar specimens are reviewed. The results of an analytical round robin that was conducted on chevron-notched specimens are presented. In the round robin, stress-intensity factors for either the chevron notched round rod or square bar specimens were calculated. The consensus stress intensity factor (compliance) solution for these specimens is assessed. The stress intensity factor solutions proposed for three and four point bend chevron notched specimens are reviewed.

  4. An MDOE Investigation of Chevrons for Supersonic Jet Noise Reduction

    NASA Technical Reports Server (NTRS)

    Henderson, Brenda; Bridges, James

    2010-01-01

    The impact of chevron design on the noise radiated from heated, overexpanded, supersonic jets is presented. The experiments used faceted bi-conic convergent-divergent nozzles with design Mach numbers equal to 1.51 and 1.65. The purpose of the facets was to simulate divergent seals on a military style nozzle. The nozzle throat diameter was equal to 4.5 inches. Modern Design of Experiment (MDOE) techniques were used to investigate the impact of chevron penetration, length, and width on the resulting acoustic radiation. All chevron configurations used 12 chevrons to match the number of facets in the nozzle. Most chevron designs resulted in increased broadband shock noise relative to the baseline nozzle. In the peak jet noise direction, the optimum chevron design reduced peak sound pressure levels by 4 dB relative to the baseline nozzle. The penetration was the parameter having the greatest impact on radiated noise at all observation angles. While increasing chevron penetration decreased acoustic radiation in the peak jet noise direction, broadband shock noise was adversely impacted. Decreasing chevron length increased noise at most observation angles. The impact of chevron width on radiated noise depended on frequency and observation angle.

  5. Flight Test Results for Uniquely Tailored Propulsion-Airframe Aeroacoustic Chevrons: Shockcell Noise

    NASA Technical Reports Server (NTRS)

    Mengle, Vinod G.; Ganz, Ulrich W.; Nesbitt, Eric; Bultemeier, Eric J.; Thomas, Russell H.; Nesbitt, Eric

    2006-01-01

    Azimuthally varying chevrons (AVC) which have been uniquely tailored to account for the asymmetric propulsion-airframe aeroacoustic interactions have recently shown significant reductions in jet-related community noise at low-speed take-off conditions in scale model tests of coaxial nozzles with high bypass ratio. There were indications that such AVCs may also provide shockcell noise reductions at high cruise speeds. This paper describes the flight test results when one such AVC concept, namely, the T-fan chevrons with enhanced mixing near the pylon, was tested at full-scale on a modern large twin-jet aircraft (777-300ER) with focus on shockcell noise at mid-cruise conditions. Shockcell noise is part of the interior cabin noise at cruise conditions and its reduction is useful from the viewpoint of passenger comfort. Noise reduction at the source, in the exhaust jet, especially, at low frequencies, is beneficial from the perspective of reduced fuselage sidewall acoustic lining. Results are shown in terms of unsteady pressure spectra both on the exterior surface of the fuselage at several axial stations and also microphone arrays placed inside the fuselage aft of the engine. The benefits of T-fan chevrons, with and without conventional chevrons on the core nozzle, are shown for several engine operating conditions at cruise involving supersonic fan stream and subsonic or supersonic core stream. The T-fan AVC alone provides up to 5 dB low-frequency noise reduction on the fuselage exterior skin and up to 2 dB reduction inside the cabin. Addition of core chevrons appears to increase the higher frequency noise. This flight test result with the previous model test observation that the T-fan AVCs have hardly any cruise thrust coefficient loss (< 0.05%) make them viable candidates for reducing interior cabin noise in high bypass ratio engines.

  6. Molecular simulation of chevrons in confined smectic liquid crystals

    NASA Astrophysics Data System (ADS)

    Webster, Richard E.; Mottram, Nigel J.; Cleaver, Douglas J.

    2003-08-01

    Chevron structures adopted by confined smectic liquid crystals are investigated via molecular dynamics simulations of the Gay-Berne model. The chevrons are formed by quenching nematic films confined between aligning planar substrates whose easy axes have opposing azimuthal components. When the substrates are perfectly smooth, the chevron formed migrates rapidly towards one of the confining walls to yield a tilted layer structure. However, when substrate roughness is included, by introducing a small-amplitude modulation to the particle-substrate interaction well depth, a symmetric chevron is formed which remains stable over sufficiently long run times for detailed structural information, such as the relevant order parameters and director orientation, to be determined. For both smooth and rough boundaries, the smectic order parameter remains nonzero across the entire chevron, implying that layer identity is maintained across the chevron tip. Also, when the surface-stabilized chevron does eventually revert to a tilted layer structure, it does so via surface slippage, such that layer integrity is maintained throughout the chevron to tilted layer relaxation process.

  7. Chevron nails: a normal variant in the pediatric population.

    PubMed

    Delano, Sofia; Belazarian, Leah

    2014-01-01

    A 7-month-old girl was evaluated for V-shaped ridging of the fingernails consistent with chevron nails. Chevron nails are a normal variant in the pediatric population that is frequently outgrown. This case nicely demonstrates this normal finding that has so rarely been reported in the literature.

  8. Flaperon Modification Effect on Jet-Flap Interaction Noise Reduction for Chevron Nozzles

    NASA Technical Reports Server (NTRS)

    Thomas, Russell H.; Mengle, Vinod G.; Stoker, Robert W.; Brusniak, Leon; Elkoby, Ronen

    2007-01-01

    Jet-flap interaction (JFI) noise can become an important component of far field noise when a flap is immersed in the engine propulsive stream or is in its entrained region, as in approach conditions for under-the-wing engine configurations. We experimentally study the effect of modifying the flaperon, which is a high speed aileron between the inboard and outboard flaps, at both approach and take-off conditions using scaled models in a free jet. The flaperon modifications were of two types: sawtooth trailing edge and mini vortex generators (vg s). Parametric variations of these two concepts were tested with a round coaxial nozzle and an advanced chevron nozzle, with azimuthally varying fan chevrons, using both far field microphone arrays and phased microphone arrays for source diagnostics purposes. In general, the phased array results corroborated the far field results in the upstream quadrant pointing to JFI near the flaperon trailing edge as the origin of the far field noise changes. Specific sawtooth trailing edges in conjunction with the round nozzle gave marginal reduction in JFI noise at approach, and parallel co-rotating mini-vg s were somewhat more beneficial over a wider range of angles, but both concepts were noisier at take-off conditions. These two concepts had generally an adverse JFI effect when used in conjunction with the advanced chevron nozzle at both approach and take-off conditions.

  9. Recent developments in Chevron mild isocracking

    SciTech Connect

    Fuchs, M.J.; Powell, B.E.; Tolberg, R.S.; Saito, Y.

    1985-01-01

    The use of Chevron's dual-catalyst mild hydrocracking technology has enabled Nippon Petroleum Refining Company (NPRC) to produce excellent yields of good-quality mid-distillate from vacuum gas oil (VGO) in an existing VGO desulfurizer at its Muroran Refinery. This technology enables refiners to take advantage of underutilized desulfurization capacity for hydrocracking with minimal additional capital investment. The Muroran unit has been in this high-conversion mode since June 1982 and has operated in the range of 10-30 liquid volume (LV) percent synthetic conversion with yields up to 48 LV percent of 680 F cut-point diesel and lighter products. The details of this operation are discussed. Laboratory pilot plant data are also presented for two different feedbacks. The amount of recoverable diesel and its quality are strong functions of the feed boiling range, synthetic conversion, and plant pressure.

  10. Impact of Fluidic Chevrons on Jet Noise

    NASA Technical Reports Server (NTRS)

    Henderson, Brenda S.; Kinzie, Kevin W.; Whitmire, Julia; Abeysinghe, Amal

    2005-01-01

    The impact of alternating fluidic core chevrons on the production of jet noise is investigated. Core nozzles for a representative 1/9th scale, bypass ratio 5 model system were manufactured with slots cut near the trailing edges to allow for air injection into the core and fan streams. The injectors followed an alternating pattern around the nozzle perimeter so that the injection alternated between injection into the core stream and injection into the fan stream. For the takeoff condition and a forward flight Mach number of 0.10, the overall sound pressure levels at the peak jet noise angle decrease with increasing injection pressure. Sound pressure levels increase for observation angles less than 110o at higher injection pressures due to increases in high frequency noise. Greater increases in high frequency noise are observed when the number of injectors increases from 8 to 12. When the forward flight Mach number is increased to 0.28, jet noise reduction (relative to the baseline) is observed at aft angles for increasing injection pressure while significant increases in jet noise are observed at forward observation angles due to substantial acoustic radiation at high frequencies. A comparison between inflow and alternating injectors shows that, for equal mass injection rates, the inflow nozzle produces greater low frequency noise reduction (relative to the baseline) than the alternating injectors at 90o and aft observation angles and a forward flight Mach number of 0.28. Preliminary computational fluid dynamic simulations indicate that the spatial decay rate of the hot potential core flow is less for the inflow nozzle than for the alternating nozzles which indicates that gentle mixing may be preferred over sever mixing when fluidic chevrons are used for jet noise reduction.

  11. Computational Analysis of a Pylon-Chevron Core Nozzle Interaction

    NASA Technical Reports Server (NTRS)

    Thomas, Russell H.; Kinzie, Kevin W.; Pao, S. Paul

    2001-01-01

    In typical engine installations, the pylon of an engine creates a flow disturbance that interacts with the engine exhaust flow. This interaction of the pylon with the exhaust flow from a dual stream nozzle was studied computationally. The dual stream nozzle simulates an engine with a bypass ratio of five. A total of five configurations were simulated all at the take-off operating point. All computations were performed using the structured PAB3D code which solves the steady, compressible, Reynolds-averaged Navier-Stokes equations. These configurations included a core nozzle with eight chevron noise reduction devices built into the nozzle trailing edge. Baseline cases had no chevron devices and were run with a pylon and without a pylon. Cases with the chevron were also studied with and without the pylon. Another case was run with the chevron rotated relative to the pylon. The fan nozzle did not have chevron devices attached. Solutions showed that the effect of the pylon is to distort the round Jet plume and to destroy the symmetrical lobed pattern created by the core chevrons. Several overall flow field quantities were calculated that might be used in extensions of this work to find flow field parameters that correlate with changes in noise.

  12. Comparison of Chevron and Distal Oblique Osteotomy for Bunion Correction.

    PubMed

    Scharer, Brandon M; DeVries, J George

    2016-01-01

    The chevron osteotomy is a standard procedure by which bunions are corrected. One of us routinely performs a distal oblique osteotomy, which, to the best of our knowledge, has not been described for the correction of bunion deformities. The purpose of the present study was to compare the short- and medium-term results of the distal oblique and chevron osteotomies for bunion correction. We performed a retrospective clinical and radiographic comparison of patients who had undergone a distal oblique or chevron osteotomy for the correction of bunion deformity. In addition, a prospective patient satisfaction survey was undertaken. A total of 55 patients were included in the present study and were treated from January 2012 to November 2014. Of the 55 patients, 27 (49.2%) were in the chevron group and 28 (50.8%) in the distal oblique group. Radiographically, no statistically significant difference was found between the 2 groups with respect to postoperative first intermetatarsal angle (p < .0001) and hallux valgus angle (p < .0001), but a greater change was found in the intermetatarsal angle in the distal oblique group (p = .467). Prospective patient satisfaction scores were available for 33 patients (60%), 16 (29%) in the chevron group and 17 (31%) in the distal oblique group. When converting the satisfaction score to a numerical score, the chevron group scored 3.3 ± 1.1 and the distal oblique group scored 3.2 ± 0.8 (p = .812). We found that the distal oblique osteotomy used in the present study is simple and reliable and showed radiographic correction and patient satisfaction equivalent to those in the chevron osteotomy. PMID:26972755

  13. LEAK AND GAS PERMEABILITY TESTING DURING SOIL-GAS SAMPLING AT HAL'S CHEVRON LUST SITE IN GREEN RIVER, UTAH

    EPA Science Inventory

    The results of gas permeability and leak testing during active soil-gas sampling at Hal’s Chevron LUST Site in Green River, Utah are presented. This study was conducted to support development of a passive soil-gas sampling method. Gas mixtures containing helium and methane were...

  14. Ambartsumyan's concept of active galactic nuclei

    NASA Astrophysics Data System (ADS)

    Khachikian, E. Ye.

    2010-01-01

    As Victor Ambartsumyan, himself, noted, the concept of active galactic nuclei occupies a special place among his scientific ideas. It was proposed more than half a century ago and was recognized by the U.S. National Academy of Sciences as revolutionary, on a copernican scale. However, by no means all of its propositions were accepted at once by large parts of the astronomy community. Nevertheless, as the American astrophysicist A. R. Sandage has written, “today, not one astronomer would deny the mystery surrounding the nuclei of galaxies or that the first to recognize the rich reward held in this treasury was Viktor Ambartsumian.” The purpose of this article is to acquaint the reader with the major stages in the formation and development of the concept of active galactic nuclei and with some of the work on this topic done at the Byurakan and other astrophysical observatories throughout the world.

  15. The effect of chevron alignment signs on driver performance on horizontal curves with different roadway geometries.

    PubMed

    Zhao, Xiaohua; Wu, Yiping; Rong, Jian; Ma, Jianming

    2015-02-01

    To develop a practicable and clear guideline for implementing Chevrons on China's highways, it is necessary to understand the effect of Chevrons on driving performance in different roadway geometries. Using a driving simulator, this study tests the effect of China's Chevrons on vehicle speed and lane position on two-lane rural highway horizontal curves with different roadway geometries. The results showed a significant effect of Chevrons on speed reduction, and this function was not significantly affected by curve radius but was statistically affected by curve direction. The speed reduction caused by Chevrons was also significant at the approach of curve, middle of curve and point of tangent. The 85th percentile speed was also markedly lower when Chevrons were present. We also found a significant effect of Chevrons in encouraging participants to drive the vehicle with a more proper lane position at the first half of curves; and this function was slightly affected by curve radius. Meanwhile, the effect of Chevrons on keeping drivers staying in a more stable lane position was also statistically significant at the second half of curves. In sharp curves, the function of Chevrons to make drivers keep a stable lane position was lost. Besides, the impact of curve direction on the function of Chevrons on lane position was always present, and drivers would drive slightly away from Chevrons. Regardless of the curve radius, China's Chevrons at horizontal curves provide an advance warning, speed control and lane position guide for traffic on the nearside of Chevrons. Besides, combing with the function of Chevrons on preventing excessive speed and the benefit to make drivers keep a more proper lane position, China's Chevrons appear to be of great benefit to reduce crashes (e.g., run-off-road) in curves. PMID:25525973

  16. Fracture toughness of brittle materials determined with chevron notch specimens

    NASA Technical Reports Server (NTRS)

    Shannon, J. L., Jr.; Bursey, R. T.; Munz, D.; Pierce, W. S.

    1980-01-01

    The use of chevron-notch specimens for determining the plane strain fracture toughness (K sub Ic) of brittle materials is discussed. Three chevron-notch specimens were investigated: short bar, short rod, and four-point-bend. The dimensionless stress intensity coefficient used in computing K sub Ic is derived for the short bar specimen from the superposition of ligament-dependent and ligament-independent solutions for the straight through crack, and also from experimental compliance calibrations. Coefficients for the four-point-bend specimen were developed by the same superposition procedure, and with additional refinement using the slice model of Bluhm. Short rod specimen stress intensity coefficients were determined only by experimental compliance calibration. Performance of the three chevron-notch specimens and their stress intensity factor relations were evaluated by tests on hot-pressed silicon nitride and sintered aluminum oxide. Results obtained with the short bar and the four-point-bend specimens on silicon nitride are in good agreement and relatively free of specimen geometry and size effects within the range investigated. Results on aluminum oxide were affected by specimen size and chevron-notch geometry, believed due to a rising crack growth resistance curve for the material. Only the results for the short bar specimen are presented in detail.

  17. Control concepts for active magnetic bearings

    NASA Technical Reports Server (NTRS)

    Siegwart, Roland; Vischer, D.; Larsonneur, R.; Herzog, R.; Traxler, Alfons; Bleuler, H.; Schweitzer, G.

    1992-01-01

    Active Magnetic Bearings (AMB) are becoming increasingly significant for various industrial applications. Examples are turbo-compressors, centrifuges, high speed milling and grinding spindles, vibration isolation, linear guides, magnetically levitated trains, vacuum and space applications. Thanks to the rapid progress and drastic cost reduction in power- and micro-electronics, the number of AMB applications is growing very rapidly. Industrial uses of AMBs leads to new requirements for AMB-actuators, sensor systems, and rotor dynamics. Especially desirable are new and better control concepts to meet demand such as low cost AMB, high stiffness, high performance, high robustness, high damping up to several kHz, vibration isolation, force-free rotation, and unbalance cancellation. This paper surveys various control concepts for AMBs and discusses their advantages and disadvantages. Theoretical and experimental results are presented.

  18. Concepts of Connectivity and Human Epileptic Activity

    PubMed Central

    Lemieux, Louis; Daunizeau, Jean; Walker, Matthew C.

    2011-01-01

    This review attempts to place the concept of connectivity from increasingly sophisticated neuroimaging data analysis methodologies within the field of epilepsy research. We introduce the more principled connectivity terminology developed recently in neuroimaging and review some of the key concepts related to the characterization of propagation of epileptic activity using what may be called traditional correlation-based studies based on EEG. We then show how essentially similar methodologies, and more recently models addressing causality, have been used to characterize whole-brain and regional networks using functional MRI data. Following a discussion of our current understanding of the neuronal system aspects of the onset and propagation of epileptic discharges and seizures, we discuss the most advanced and ambitious framework to attempt to fully characterize epileptic networks based on neuroimaging data. PMID:21472027

  19. The Chevron Foil Thrust Bearing: Improved Performance Through Passive Thermal Management and Effective Lubricant Mixing

    NASA Technical Reports Server (NTRS)

    Bruckner, Robert

    2013-01-01

    An improved foil thrust bearing is described that eliminates or reduces the need for forced cooling of the bearing foils while at the same time improves the load capacity of the bearing, enhances damping, provides overload tolerance, and eliminates the high speed load capacity drop-off that plagues the current state of the art. The performance improvement demonstrated by the chevron foil thrust bearing stems from a novel trailing edge shape that splays the hot lubricant in the thin film radially, thus preventing hot lubricant carry-over into the ensuing bearing sector. Additionally, the chevron shaped trailing edge induces vortical mixing of the hot lubricant with the gas that is naturally resident within the inter-pad region of a foil thrust bearing. The elimination of hot gas carry-over in combination with the enhanced mixing has enabled a completely passive thermally managed foil bearing design. Laboratory testing at NASA has confirmed the original analysis and reduced this concept to practice.

  20. Articles which include chevron film cooling holes, and related processes

    SciTech Connect

    Bunker, Ronald Scott; Lacy, Benjamin Paul

    2014-12-09

    An article is described, including an inner surface which can be exposed to a first fluid; an inlet; and an outer surface spaced from the inner surface, which can be exposed to a hotter second fluid. The article further includes at least one row or other pattern of passage holes. Each passage hole includes an inlet bore extending through the substrate from the inlet at the inner surface to a passage hole-exit proximate to the outer surface, with the inlet bore terminating in a chevron outlet adjacent the hole-exit. The chevron outlet includes a pair of wing troughs having a common surface region between them. The common surface region includes a valley which is adjacent the hole-exit; and a plateau adjacent the valley. The article can be an airfoil. Related methods for preparing the passage holes are also described.

  1. Active Ways to Teach Health Concepts in the Elementary Setting

    ERIC Educational Resources Information Center

    Gregory, Julie

    2015-01-01

    This article provides three movement-based activities for teaching health concepts to elementary school students. Two activities focus on nutrition concepts and the other focuses on teaching body systems. Diagrams are provided to show the setup of activities, as well as links for accessing materials to help implement the activities.

  2. Space Adaptation of Active Mirror Segment Concepts

    NASA Technical Reports Server (NTRS)

    Ames, Gregory H.

    1999-01-01

    This report summarizes the results of a three year effort by Blue Line Engineering Co. to advance the state of segmented mirror systems in several separate but related areas. The initial set of tasks were designed to address the issues of system level architecture, digital processing system, cluster level support structures, and advanced mirror fabrication concepts. Later in the project new tasks were added to provide support to the existing segmented mirror testbed at Marshall Space Flight Center (MSFC) in the form of upgrades to the 36 subaperture wavefront sensor. Still later, tasks were added to build and install a new system processor based on the results of the new system architecture. The project was successful in achieving a number of important results. These include the following most notable accomplishments: 1) The creation of a new modular digital processing system that is extremely capable and may be applied to a wide range of segmented mirror systems as well as many classes of Multiple Input Multiple Output (MIMO) control systems such as active structures or industrial automation. 2) A new graphical user interface was created for operation of segmented mirror systems. 3) The development of a high bit rate serial data loop that permits bi-directional flow of data to and from as many as 39 segments daisy-chained to form a single cluster of segments. 4) Upgrade of the 36 subaperture Hartmann type Wave Front Sensor (WFS) of the Phased Array Mirror, Extendible Large Aperture (PAMELA) testbed at MSFC resulting in a 40 to 5OX improvement in SNR which in turn enabled NASA personnel to achieve many significant strides in improved closed-loop system operation in 1998. 5) A new system level processor was built and delivered to MSFC for use with the PAMELA testbed. This new system featured a new graphical user interface to replace the obsolete and non-supported menu system originally delivered with the PAMELA system. The hardware featured Blue Line's new stackable

  3. 75 FR 51479 - Notice of Availability of the Final Environmental Impact Statement for the Chevron Energy...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-20

    ...) was published by EPA in the Federal Register on March 19, 2010 (75 FR 13301). The formal 90- day... Chevron Energy Solutions/Solar Millennium Blythe Solar Power Plant and Proposed California Desert... Impact Statement (EIS) for the Chevron Energy Solutions/Solar Millennium (CESSM), LLC's Blythe...

  4. Acoustic Efficiency of Azimuthal Modes in Jet Noise Using Chevron Nozzles

    NASA Technical Reports Server (NTRS)

    Brown, Clifford A.; Bridges, James

    2006-01-01

    The link between azimuthal modes in jet turbulence and in the acoustic sound field has been examined in cold, round jets. Chevron nozzles, however, impart an azimuthal structure on the jet with a shape dependent on the number, length and penetration angle of the chevrons. Two particular chevron nozzles, with 3 and 4 primary chevrons respectively, and a round baseline nozzle are compared at both cold and hot jet conditions to determine how chevrons impact the modal structure of the flow and how that change relates to the sound field. The results show that, although the chevrons have a large impact on the azimuthal shape of the mean axial velocity, the impact of chevrons on the azimuthal structure of the fluctuating axial velocity is small at the cold jet condition and smaller still at the hot jet condition. This is supported by results in the azimuthal structure of the sound field, which also shows little difference in between the two chevron nozzles and the baseline nozzle in the distribution of energy across the azimuthal modes measured.

  5. Catalytic dehazing of heavy lube oil - A chevron case history

    SciTech Connect

    Zakarian, J.A.; Ziemer, J.N.

    1987-01-01

    In the fall of 1984, Chevron started up a new plant in Richmond, California, to make high-V.I. lube base oils. After about eight months onstream, the heavy neutral product became hazy. The haze was caused by wax which had leaked into the oil through tiny holes in the canvas filter cloths at the solvent dewaxing plant. The haze was difficult to detect and control because it required many days to form and it resulted from parts per million quantities of wax. The haze problem was intermittent and unpredictable, occurring as filter cloths aged. Consequently, the solvent dewaxing plant was limited in capacity and flexibility because of the need to reprocess hazy oil. To improve operating economics and product quality, Chevron developed a dehazing process. The process uses a catalyst downstream of the solvent dewaxer to remove inadvertent wax contaminants. The catalyst was loaded in the upper portion of an existing hydrofinishing reactor so that there were no expenditures for new equipment. Since the process went onstream in the fall of 1985, the heavy neutral lube oil has been consistently haze free.

  6. Chevron beam dump for ITER edge Thomson scattering system

    NASA Astrophysics Data System (ADS)

    Yatsuka, E.; Hatae, T.; Vayakis, G.; Bassan, M.; Itami, K.

    2013-10-01

    This paper contains the design of the beam dump for the ITER edge Thomson scattering system and mainly concerns its lifetime under the harsh thermal and electromagnetic loads as well as tight space allocation. The lifetime was estimated from the multi-pulse laser-induced damage threshold. In order to extend its lifetime, the structure of the beam dump was optimized. A number of bent sheets aligned parallel in the beam dump form a shape called a chevron which enables it to avoid the concentration of the incident laser pulse energy. The chevron beam dump is expected to withstand thermal loads due to nuclear heating, radiation from the plasma, and numerous incident laser pulses throughout the entire ITER project with a reasonable margin for the peak factor of the beam profile. Structural analysis was also carried out in case of electromagnetic loads during a disruption. Moreover, detailed issues for more accurate assessments of the beam dump's lifetime are clarified. Variation of the bi-directional reflection distribution function (BRDF) due to erosion by or contamination of neutral particles derived from the plasma is one of the most critical issues that needs to be resolved. In this paper, the BRDF was assumed, and the total amount of stray light and the absorbed laser energy profile on the beam dump were evaluated.

  7. Chevron beam dump for ITER edge Thomson scattering system.

    PubMed

    Yatsuka, E; Hatae, T; Vayakis, G; Bassan, M; Itami, K

    2013-10-01

    This paper contains the design of the beam dump for the ITER edge Thomson scattering system and mainly concerns its lifetime under the harsh thermal and electromagnetic loads as well as tight space allocation. The lifetime was estimated from the multi-pulse laser-induced damage threshold. In order to extend its lifetime, the structure of the beam dump was optimized. A number of bent sheets aligned parallel in the beam dump form a shape called a chevron which enables it to avoid the concentration of the incident laser pulse energy. The chevron beam dump is expected to withstand thermal loads due to nuclear heating, radiation from the plasma, and numerous incident laser pulses throughout the entire ITER project with a reasonable margin for the peak factor of the beam profile. Structural analysis was also carried out in case of electromagnetic loads during a disruption. Moreover, detailed issues for more accurate assessments of the beam dump's lifetime are clarified. Variation of the bi-directional reflection distribution function (BRDF) due to erosion by or contamination of neutral particles derived from the plasma is one of the most critical issues that needs to be resolved. In this paper, the BRDF was assumed, and the total amount of stray light and the absorbed laser energy profile on the beam dump were evaluated.

  8. Simulating MEMS Chevron Actuator for Strain Engineering 2D Materials

    NASA Astrophysics Data System (ADS)

    Vutukuru, Mounika; Christopher, Jason; Bishop, David; Swan, Anna

    2D materials pose an exciting paradigm shift in the world of electronics. These crystalline materials have demonstrated high electric and thermal conductivities and tensile strength, showing great potential as the new building blocks of basic electronic circuits. However, strain engineering 2D materials for novel devices remains a difficult experimental feat. We propose the integration of 2D materials with MEMS devices to investigate the strain dependence on material properties such as electrical and thermal conductivity, refractive index, mechanical elasticity, and band gap. MEMS Chevron actuators, provides the most accessible framework to study strain in 2D materials due to their high output force displacements for low input power. Here, we simulate Chevron actuators on COMSOL to optimize actuator design parameters and accurately capture the behavior of the devices while under the external force of a 2D material. Through stationary state analysis, we analyze the response of the device through IV characteristics, displacement and temperature curves. We conclude that the simulation precisely models the real-world device through experimental confirmation, proving that the integration of 2D materials with MEMS is a viable option for constructing novel strain engineered devices. The authors acknowledge support from NSF DMR1411008.

  9. Image potential states at chevron-shaped graphene nanoribbons /Au(111) interfaces

    NASA Astrophysics Data System (ADS)

    Bronner, Christopher; Haase, Anton; Tegeder, Petra

    2015-01-01

    Image potential states (IPSs) have been observed for various adsorbed carbon structures, such as graphene or carbon nanotubes. Graphene nanoribbons (GNRs) are intriguing nanostructures with a significant band gap which promise applications in nanotechnology. In the present paper we employ two-photon photoemission (2PPE) to investigate the unoccupied electronic structure and particularly the IPS of chevron-shaped GNR which are synthesized in a thermally activated on-surface synthesis on Au(111). Angle- and time-resolved 2PPE are utilized to gain further insights into the properties of the IPS. Compared to the pristine surface, reduced effective masses between 0.6 and 0.8 electron masses are observed and the lifetimes of the IPS are below the experimental detection limit, which is in the femtosecond regime. Independent of the concentration of N dopant atoms introduced in the GNR we observe a constant binding energy with respect to the vacuum level of the system.

  10. Computational Analysis of a Chevron Nozzle Uniquely Tailored for Propulsion Airframe Aeroacoustics

    NASA Technical Reports Server (NTRS)

    Massey, Steven J.; Elmiligui, Alaa A.; Hunter, Craig A.; Thomas, Russell H.; Pao, S. Paul; Mengle, Vinod G.

    2006-01-01

    A computational flow field and predicted jet noise source analysis is presented for asymmetrical fan chevrons on a modern separate flow nozzle at take off conditions. The propulsion airframe aeroacoustic asymmetric fan nozzle is designed with an azimuthally varying chevron pattern with longer chevrons close to the pylon. A baseline round nozzle without chevrons and a reference nozzle with azimuthally uniform chevrons are also studied. The intent of the asymmetric fan chevron nozzle was to improve the noise reduction potential by creating a favorable propulsion airframe aeroacoustic interaction effect between the pylon and chevron nozzle. This favorable interaction and improved noise reduction was observed in model scale tests and flight test data and has been reported in other studies. The goal of this study was to identify the fundamental flow and noise source mechanisms. The flow simulation uses the asymptotically steady, compressible Reynolds averaged Navier-Stokes equations on a structured grid. Flow computations are performed using the parallel, multi-block, structured grid code PAB3D. Local noise sources were mapped and integrated computationally using the Jet3D code based upon the Lighthill Acoustic Analogy with anisotropic Reynolds stress modeling. In this study, trends of noise reduction were correctly predicted. Jet3D was also utilized to produce noise source maps that were then correlated to local flow features. The flow studies show that asymmetry of the longer fan chevrons near the pylon work to reduce the strength of the secondary flow induced by the pylon itself, such that the asymmetric merging of the fan and core shear layers is significantly delayed. The effect is to reduce the peak turbulence kinetic energy and shift it downstream, reducing overall noise production. This combined flow and noise prediction approach has yielded considerable understanding of the physics of a fan chevron nozzle designed to include propulsion airframe aeroacoustic

  11. Experimental investigation of heat transfer and effectiveness in corrugated plate heat exchangers having different chevron angles

    NASA Astrophysics Data System (ADS)

    Kılıç, Bayram; İpek, Osman

    2016-06-01

    In this study, heat transfer rate and effectiveness of corrugated plate heat exchangers having different chevron angles were investigated experimentally. Chevron angles of plate heat exchangers are β = 30° and β = 60°. For this purpose, experimentally heating system used plate heat exchanger was designed and constructed. Thermodynamic analysis of corrugated plate heat exchangers having different chevron angles were carried out. The heat transfer rate and effectiveness values are calculated. The experimental results are shown that heat transfer rate and effectiveness values for β = 60° is higher than that of the other. Obtained experimental results were graphically presented.

  12. Collaborative Concept Mapping Activities in a Classroom Scenario

    ERIC Educational Resources Information Center

    Elorriaga, J. A.; Arruarte, A.; Calvo, I.; Larrañaga, M.; Rueda, U.; Herrán, E.

    2013-01-01

    The aim of this study is to test collaborative concept mapping activities using computers in a classroom scenario and to evaluate the possibilities that Elkar-CM offers for collaboratively learning non-technical topics. Elkar-CM is a multi-lingual and multi-media software program designed for drawing concept maps (CMs) collaboratively. Concept…

  13. Concepts of disability: the Activity Space Model.

    PubMed

    Kopec, J A

    1995-03-01

    This paper describes a new conceptual framework for functional assessment, the Activity Space Model (ASM). According to this model, functional impairments may lead to restrictions in an individual's activity space, a multidimensional space that represents human potential for activity. For each elementary ability, restrictions in the corresponding dimension of the activity space can be evaluated by deriving a difficulty curve that depicts the relationship between the level of performance and the psychophysical cost of activity. The effect of disease on daily functioning is explained in terms of a tradeoff between the psychophysical cost and the value of each act of behavior to the disabled individual. These two constructs are measured on the same scale and expressed in units of difficulty. The location of each task within the activity space in relation to the difficulty curve determines whether it will be performed or avoided at a given point in time. The ASM has both theoretical and practical implications. It offers a new, integrated perspective on disability and suggests new strategies for developing and evaluating functional assessment measures.

  14. Physical activity and mental health: current concepts.

    PubMed

    Paluska, S A; Schwenk, T L

    2000-03-01

    Physical activity may play an important role in the management of mild-to-moderate mental health diseases, especially depression and anxiety. Although people with depression tend to be less physically active than non-depressed individuals, increased aerobic exercise or strength training has been shown to reduce depressive symptoms significantly. However, habitual physical activity has not been shown to prevent the onset of depression. Anxiety symptoms and panic disorder also improve with regular exercise, and beneficial effects appear to equal meditation or relaxation. In general, acute anxiety responds better to exercise than chronic anxiety. Studies of older adults and adolescents with depression or anxiety have been limited, but physical activity appears beneficial to these populations as well. Excessive physical activity may lead to overtraining and generate psychological symptoms that mimic depression. Several differing psychological and physiological mechanisms have been proposed to explain the effect of physical activity on mental health disorders. Well controlled studies are needed to clarify the mental health benefits of exercise among various populations and to address directly processes underlying the benefits of exercise on mental health.

  15. Active Control by Conservation of Energy Concept

    NASA Technical Reports Server (NTRS)

    Maestrello, Lucio

    2000-01-01

    Three unrelated experiments are discussed; each was extremely sensitive to initial conditions. The initial conditions are the beginnings of the origins of the information that nonlinearity displays. Initial conditions make the phenomenon unstable and unpredictable. With the knowledge of the initial conditions, active control requires far less power than that present in the system response. The first experiment is on the control of shocks from an axisymmetric supersonic jet; the second, control of a nonlinear panel response forced by turbulent boundary layer and sound; the third, control of subharmonic and harmonics of a panel forced by sound. In all three experiments, control is achieved by redistribution of periodic energy response such that the energy is nearly preserved from a previous uncontrolled state. This type of active control improves the performance of the system being controlled.

  16. Trailing edge cooling using angled impingement on surface enhanced with cast chevron arrangements

    SciTech Connect

    Lee, Ching-Pang; Heneveld, Benjamin E.; Brown, Glenn E.; Klinger, Jill

    2015-05-26

    A gas turbine engine component, including: a pressure side (12) having an interior surface (34); a suction side (14) having an interior surface (36); a trailing edge portion (30); and a plurality of suction side and pressure side impingement orifices (24) disposed in the trailing edge portion (30). Each suction side impingement orifice is configured to direct an impingement jet (48) at an acute angle (52) onto a target area (60) that encompasses a tip (140) of a chevron (122) within a chevron arrangement (120) formed in the suction side interior surface. Each pressure side impingement orifice is configured to direct an impingement jet at an acute angle onto an elongated target area that encompasses a tip of a chevron within a chevron arrangement formed in the pressure side interior surface.

  17. 76 FR 63294 - Chevron Products Company v. SFPP, L.P. ; Notice of Complaint

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-12

    ... Act (ICA), and 49 USC App. 13(1), Chevron Products Company (Complainants) filed a complaint against... violate the ICA by applying the increased ceiling rates which are unjust and unreasonable for...

  18. Fractured toughness of Si3N4 measured with short bar chevron-notched specimens

    NASA Technical Reports Server (NTRS)

    Salem, J. A.; Shannon, J. L., Jr.

    1985-01-01

    The short bar chevron-notched specimen is used to measure the plane strain fracture toughness of hot pressed Si3N4. Specimen proportions and chevron-notch angle are varied, thereby varying the amount of crack extension to maximum load (upon which K sub IC is based). The measured toughness (4.68 + or - 0.19 MNm to the 3/2 power) is independent of these variations, inferring that the material has a flat crack growth resistance curve.

  19. Effect of chevrons on the slat noise of straight and swept wings

    NASA Astrophysics Data System (ADS)

    Belyaev, I. V.; Zaytsev, M. Yu.; Kopiev, V. F.

    2015-11-01

    An experimental study of the airframe noise for small-scale wing models with high-lift devices (slat and flap) is performed. It is shown that installation of chevrons on the lower edge of a slat leads to noise reduction on both straight and swept wings. Simultaneous acoustic and aerodynamic measurements show that chevrons lead to suppression of the slat tonal noise components without significantly affecting the wing aerodynamics.

  20. Reducing Propulsion Airframe Aeroacoustic Interactions with Uniquely Tailored Chevrons. 1.; Isolated Nozzles

    NASA Technical Reports Server (NTRS)

    Mengle, Vinod G.; Elkroby, Ronen; Brunsniak, Leon; Thomas, Russ H.

    2006-01-01

    The flow/acoustic environment surrounding an engine nozzle installed on an airplane, say, under the wing, is asymmetric due to the pylon, the wing and the interaction of the exhaust jet with flaps on the wing. However, the conventional chevrons, which are azimuthally uniform serrations on the nozzle lip, do not exploit the asymmetry due to these propulsion airframe aeroacoustic interactions to reduce jet noise. In this pioneering study we use this non-axisymmetry to our advantage and examine if the total jet-related noise radiated to the ground can be reduced by using different types of azimuthally varying chevrons (AVC) which vary the mixing around the nozzle periphery. Several scale models of the isolated nozzle, representative of high bypass ratio engine nozzles, were made with a pylon and azimuthally varying chevrons on both fan and core nozzles to enhance mixing at the top (near the pylon) with less mixing at the bottom (away from the pylon) or vice versa. Various combinations of fan and core AVC nozzles were systematically tested at typical take-off conditions inside a free jet wind-tunnel and, here, in Part 1 we analyze the acoustics results for the isolated nozzle with a pylon, with installation effects reported in Parts 2 and 3. Several interesting results are discovered: amongst the fan AVCs the top-enhanced mixing T-fan chevron nozzle is quieter in combination with any core AVC nozzle when compared to conventional chevrons; however, the bottom-mixing B-fan chevrons, as well as the core AVC nozzles, by themselves, are noisier. Further, the low-frequency source strengths in the jet plume, obtained via phased microphone arrays, also corroborate the far field sound, and for the T-fan chevrons such sources move further downstream than those for baseline or conventional chevron nozzles.

  1. CFD Analyses and Jet-Noise Predictions of Chevron Nozzles with Vortex Stabilization

    NASA Technical Reports Server (NTRS)

    Dippold, Vance

    2008-01-01

    The wind computational fluid dynamics code was used to perform a series of analyses on a single-flow plug nozzle with chevrons. Air was injected from tubes tangent to the nozzle outer surface at three different points along the chevron at the nozzle exit: near the chevron notch, at the chevron mid-point, and near the chevron tip. Three injection pressures were used for each injection tube location--10, 30, and 50 psig-giving injection mass flow rates of 0.1, 0.2, and 0.3 percent of the nozzle mass flow. The results showed subtle changes in the jet plume s turbulence and vorticity structure in the region immediately downstream of the nozzle exit. Distinctive patterns in the plume structure emerged from each injection location, and these became more pronounced as the injection pressure was increased. However, no significant changes in centerline velocity decay or turbulent kinetic energy were observed in the jet plume as a result of flow injection. Furthermore, computational acoustics calculations performed with the JeNo code showed no real reduction in jet noise relative to the baseline chevron nozzle.

  2. A Measurement Activity to Encourage Exploration of Calculus Concepts

    ERIC Educational Resources Information Center

    McGuffey, William

    2015-01-01

    This article describes an activity that incorporates measurement in order to lead students to discover and explore fundamental concepts of calculus. Students are provided with an experientially real starting point involving measurement and are encouraged to engage in mathematical discussions in a low-stakes environment. I describe the activity as…

  3. Presupposition Processing and the (Re)activation of Negated Concepts

    ERIC Educational Resources Information Center

    Autry, Kevin S.; Levine, William H.

    2014-01-01

    Negated words take longer to recognize than non-negated words following sentences with negation, suggesting that negated concepts are less active. The present experiments tested the possibility that this reduced activation would not persist beyond immediate testing. Experiment 1 used a probe task and materials similar to those used in previous…

  4. Grounding Abstractness: Abstract Concepts and the Activation of the Mouth

    PubMed Central

    Borghi, Anna M.; Zarcone, Edoardo

    2016-01-01

    One key issue for theories of cognition is how abstract concepts, such as freedom, are represented. According to the WAT (Words As social Tools) proposal, abstract concepts activate both sensorimotor and linguistic/social information, and their acquisition modality involves the linguistic experience more than the acquisition of concrete concepts. We report an experiment in which participants were presented with abstract and concrete definitions followed by concrete and abstract target-words. When the definition and the word matched, participants were required to press a key, either with the hand or with the mouth. Response times and accuracy were recorded. As predicted, we found that abstract definitions and abstract words yielded slower responses and more errors compared to concrete definitions and concrete words. More crucially, there was an interaction between the target-words and the effector used to respond (hand, mouth). While responses with the mouth were overall slower, the advantage of the hand over the mouth responses was more marked with concrete than with abstract concepts. The results are in keeping with grounded and embodied theories of cognition and support the WAT proposal, according to which abstract concepts evoke linguistic-social information, hence activate the mouth. The mechanisms underlying the mouth activation with abstract concepts (re-enactment of acquisition experience, or re-explanation of the word meaning, possibly through inner talk) are discussed. To our knowledge this is the first behavioral study demonstrating with real words that the advantage of the hand over the mouth is more marked with concrete than with abstract concepts, likely because of the activation of linguistic information with abstract concepts. PMID:27777563

  5. Fatigue analysis of chevron structures with Z shape arms

    NASA Astrophysics Data System (ADS)

    Tecpoyotl Torres, Margarita; Cabello Ruiz, Ramón; Vera Dimas, J. G.; Rodriguez Ramirez, J. Alfredo; Escobedo Alatorre, J. Jesus; Ocampo Diaz, Alejandra

    2015-08-01

    Due to the diversity and multiple energy domains involved, Micro-Electromechanical Systems MEMS devices are vulnerable to several mechanical failures such as fatigue. They been widely used in military applications, radio frequency systems, pressure sensors, automotive industry, among several others. Most MEMS devices contain moving parts that are subjected to cyclic loading, which degrade the devicés efficiency. Due to the high importance of MEMS in various applications, it is necessary to know their lifetime to prevent any damage or process discontinuity to which the system is subject. There have been several investigations in particular on the fatigue analysis in presence of cracks, however in terms of lifetime under cycling load, information is not abundant. The fatigue analysis can be performed for characterizing the ability of materials to support many cycles. Some parts of systems are exposed to strong stress level experiences during its usable lifetime, so the analysis must be focused on them. In this paper, a simulated fatigue analysis of classic, Z-shape and optimized chevron with Z shape arms is shown. Simulations are made using Ansys 15.0, to obtain the arms lifetime of the system because they are subjected to greater stresses in the presence of cyclic loading.

  6. Reducing Propulsion Airframe Aeroacoustic Interactions With Uniquely Tailored Chevrons: 3. Jet-Flap Interaction

    NASA Technical Reports Server (NTRS)

    Thomas, Russ H.; Mengle, Vinod G.; Brunsniak, Leon; Elkoby, Ronen

    2006-01-01

    Propulsion airframe aeroacoustic (PAA) interactions, resulting from the integration of engine and airframe, lead to azimuthal asymmetries in the flow/acoustic field, e.g., due to the interaction between the exhaust jet flow and the pylon, the wing and its high-lift devices, such as, flaps and flaperons. In the first two parts of this series we have presented experimental results which show that isolated and installed nozzles with azimuthally varying chevrons (AVCs) can reduce noise more than conventional chevrons when integrated with a pylon and a wing with flaps at take-off conditions. In this paper, we present model-scale experimental results for the reduction of jet-flap interaction noise source due to these AVCs and document the PAA installation effects (difference in noise between installed and isolated nozzle configurations) at both approach and take-off conditions. It is found that the installation effects of both types of chevron nozzles, AVCs and conventional, are reversed at approach and take-off, in that there is more installed noise reduction at approach and less at take-off compared to that of the isolated nozzles. Moreover, certain AVCs give larger total installed noise benefits at both conditions compared to conventional chevrons. Phased microphone array results show that at approach conditions (large flap deflection, low jet speed and low ambient Mach number), chevrons gain more noise benefit from reducing jetflap interaction noise than they do from quieting the jet plume noise source which is already weak at these low jet speeds. In contrast, at take-off (small flap deflection, high jet speed and high ambient Mach number) chevrons reduce the dominant jet plume noise better than the reduction they create in jet-flap interaction noise source. In addition, fan AVCs with enhanced mixing near the pylon are found to reduce jet-flap interaction noise better than conventional chevrons at take-off.

  7. En otras palabras: Illustrated Grammatical Concepts and Communicative Activities.

    ERIC Educational Resources Information Center

    Carfora, Juanita; Carfora, Lolita

    This manual, designed for teachers of Spanish as a second language, contains visual aids to illustrate certain grammatical concepts and related vocabulary. The manual consists of 30 tear-out blackline masters, each containing one to six separate cartoon pictures, to be used for classroom or homework activities in any sequence. Accompanying each…

  8. Self-Concept and Participation in School Activities Reanalyzed.

    ERIC Educational Resources Information Center

    Winne, Philip H.; Walsh, John

    1980-01-01

    Yarworth and Gauthier (EJ 189 606) examined whether self-concept variables enhanced predictions about students' participation in school activities, using unstructured stepwise regression techniques. A reanalysis of their data using hierarchial regression models tested their hypothesis more appropriately, and uncovered multicollinearity and…

  9. PIV Measurements of Chevrons on F400 Tactical Aircraft Nozzle Model

    NASA Technical Reports Server (NTRS)

    Bridges, James; Wernet, Mark; Frate, Franco

    2010-01-01

    Previous talks at this meeting have covered our collaborative work on high-energy jets such as present in tactical aircraft (those with supersonic plumes). The emphasis of this work is improving our understanding of flow physics and our prediction tools. In this presentation we will discuss recent flow diagnostics acquired using Particle Image Velocimetry (PIV) made on an underexpanded shocked jet plume from a tactical aircraft nozzle. In this presentation we show cross-sectional and streamwise cuts of both mean and turbulent velocities of an F404 engine nozzle with various chevron designs applied. The impact of chevron penetration, length, and width are documented. The impact of the parameters is generally nonlinear in measures considered here, a surprising result given the relatively smooth behavior of the noise to variations in these chevron parameters.

  10. 78 FR 69659 - Chevron U.S.A. Inc. v. Kinder Morgan Louisiana Pipeline LLC; Notice of Complaint

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Chevron U.S.A. Inc. v. Kinder Morgan Louisiana Pipeline LLC; Notice of.... (Chevron or Complainant), filed a complaint against Kinder Morgan Louisiana Pipeline LLC (KMLP...

  11. 75 FR 62852 - Notice of Availability of the Record of Decision for the Chevron Energy Solutions Lucerne Valley...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-13

    ... Bureau of Land Management Notice of Availability of the Record of Decision for the Chevron Energy Solutions Lucerne Valley Solar Project, California and the Approved Plan Amendment to the California Desert...)/Approved Plan Amendment (PA) to the California Desert Conservation Area (CDCA) Plan for the Chevron...

  12. The fate of activated information in impression formation: fluency of concept activation moderates the emergence of assimilation versus contrast.

    PubMed

    Greifeneder, Rainer; Bless, Herbert

    2010-06-01

    Prior research has shown that activated concepts may influence subsequent interpretation and judgmental processes via priming. Building on this evidence, we suggest that the fluency associated with concept activation may determine whether activated content elicits assimilation or contrast. In two experiments, concept activation in a typical priming experiment was rendered fluent or non-fluent. Consistent with hypotheses, fluent concept activation led to assimilation, whereas non-fluent concept activation led to contrast.

  13. Chevron starts U.S. gulf`s first Lower Cretaceous flow

    SciTech Connect

    Petzet, G.A.

    1998-06-15

    Chevron plans to start production from its Mobile 991 No. 1 well this month. The trend`s first producer is the Viosca Knoll 68 No. 2 well, which went on line April 26 at the anticipated rate of about 15 MMcfd of gas. Chevron has also tested its Viosca Knoll 114 discovery well, drilled in August 1997. Five gas discoveries since 1994 in a trend that extends now Mobile Block 991 to Viosca Knoll Block 252 have recoverable reserve potential of over 600 bcf (gross trend) of natural gas. The paper describes the carbonate trend and exploring the Lower Cretaceous James deposit.

  14. The relationship between perceived length and egocentric location in Muller-Lyer figures with one versus two chevrons

    NASA Technical Reports Server (NTRS)

    Welch, Robert B.; Post, Robert B.; Lum, Wayland; Prinzmetal, William

    2004-01-01

    We examined the apparent dissociation of perceived length and perceived position with respect to the Muller-Lyer (M-L) illusion. With the traditional (two-chevron) figure, participants made accurate open-loop pointing responses at the endpoints of the shaft, despite the presence of a strong length illusion. This apparently non-Euclidean outcome replicated that of Mack, Heuer, Villardi, and Chambers (1985) and Gillam and Chambers (1985) and contradicts any theory of the M-L illusion in which mislocalization of shaft endpoints plays a role. However, when one of the chevrons was removed, a constant pointing error occurred in the predicted direction, as well as a strong length illusion. Thus, with one-chevron stimuli, perceived length and location were no longer completely dissociated. We speculated that the presence of two opposing chevrons suppresses the mislocalizing effects of a single chevron, especially for figures with relatively short shafts.

  15. Selected advanced aerodynamic and active control concepts development

    NASA Technical Reports Server (NTRS)

    1980-01-01

    A summary is presented of results obtained during analysis, design and test activities on six selected technical tasks directed at exploratory improvement of fuel efficiency for new and derivative transports. The work included investigations into the potential offered by natural laminar flow, improved surface coatings and advanced high lift concepts. Similar investigations covering optimum low-energy flight path control, integrated application of active controls and evaluation of primary flight control systems reliability and maintenance are also summarized. Recommendations are included for future work needed to exploit potential advancements.

  16. Overview on NASA's Advanced Electric Propulsion Concepts Activities

    NASA Technical Reports Server (NTRS)

    Frisbee, Robert H.

    1999-01-01

    Advanced electric propulsion research activities are currently underway that seek to addresses feasibility issues of a wide range of advanced concepts, and may result in the development of technologies that will enable exciting new missions within our solar system and beyond. Each research activity is described in terms of the present focus and potential future applications. Topics include micro-electric thrusters, electrodynamic tethers, high power plasma thrusters and related applications in materials processing, variable specific impulse plasma thrusters, pulsed inductive thrusters, computational techniques for thruster modeling, and advanced electric propulsion missions and systems studies.

  17. Feedback Control of a Morphing Chevron for Takeoff and Cruise Noise Reduction

    NASA Technical Reports Server (NTRS)

    Cabell, Randolph H.; Schiller, Noah H.; Mabe, James H.; Ruggeri, Robert T.; Butler, G. W.

    2004-01-01

    Noise from commercial high-bypass ratio turbofan engines is generated by turbulent mixing of the hot jet exhaust, fan stream, and ambient air. Serrated aerodynamic devices, known as chevrons, along the trailing edges of a jet engine primary and secondary exhaust nozzle have been shown to reduce jet noise at takeoff and shock-cell noise at cruise conditions. Their optimum shape is a finely tuned compromise between noise-benefit and thrust-loss. The design of a full scale Variable Geometry Chevron (VGC) fan-nozzle incorporating Shape Memory Alloy (SMA) actuators is described in a companion paper. This paper describes the development and testing of a proportional-integral control system that regulates the heating of the SMA actuators to control the VGC s tip immersion. The VGC and control system were tested under representative flow conditions in Boeing s Nozzle Test Facility (NTF). Results from the NTF test which demonstrate controllable immersion of the VGC are described. The paper also describes the correlation between strains and temperatures on the chevron with a photogrammetric measurement of the chevron's tip immersion.

  18. Stress Intensity Factors of Semi-Circular Bend Specimens with Straight-Through and Chevron Notches

    NASA Astrophysics Data System (ADS)

    Ayatollahi, M. R.; Mahdavi, E.; Alborzi, M. J.; Obara, Y.

    2016-04-01

    Semi-circular bend specimen is one of the useful test specimens for determining fracture toughness of rock and geo-materials. Generally, in rock test specimens, initial cracks are produced in two shapes: straight-edge cracks and chevron notches. In this study, the minimum dimensionless stress intensity factors of semi-circular bend specimen (SCB) with straight-through and chevron notches are calculated. First, using finite element analysis, a suitable relation for the dimensionless stress intensity factor of SCB with straight-through crack is presented based on the normalized crack length and half-distance between supports. For evaluating the validity and accuracy of this relation, the obtained results are then compared with numerical and experimental results reported in the literature. Subsequently, by performing some experiments and also finite element analysis of the SCB specimen with chevron notch, the minimum dimensionless stress intensity factor of this specimen is obtained. Using the new equation for the dimensionless stress intensity factor of SCB with straight-through crack and an analytical method, i.e., Bluhm's slice synthesis method, the minimum (critical) dimensionless stress intensity factor of chevron notched semi-circular bend specimens is calculated. Good agreement is observed between the results of two mentioned methods.

  19. Creative Collaboration between Chevron and CSUB: Research Experience Vitalizing Science -- University Program

    ERIC Educational Resources Information Center

    Wang, Jianjun

    2013-01-01

    Since 2007, Chevron has funded the Research Experience Vitalizing Science -- University Program (REVS-UP), which lasts four weeks each summer to develop Science, Technology, Engineering, and Mathematics (STEM) projects at CSUB [California State University, Bakersfield]. Over the past six years, a total of 26 STEM professors have led the…

  20. 76 FR 35880 - Chevron Products Company v. SFPP, L.P.; Notice of Complaint

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Chevron Products Company v. SFPP, L.P.; Notice of Complaint Take notice that....0.0, and 200.0.0 and all predecessor tariffs, supplements and re-issuances. The Complainant...

  1. 76 FR 35881 - Chevron Products Company v. SFPP, L.P.; Notice of Complaint

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Chevron Products Company v. SFPP, L.P.; Notice of Complaint Take notice that....0, and 200.1.0 and successor tariffs, supplements and reissuances. The Complainant states that...

  2. Analysis of some compliance calibration data for chevron-notch bar and rod specimens

    NASA Technical Reports Server (NTRS)

    Orange, Thomas W.; Bubsey, Raymond T.; Pierce, William S.; Shannon, John L., Jr.

    1991-01-01

    A set of equations describing certain fracture mechanics parameters for chevron-notch bar and rod specimens are presented. They are developed by fitting earlier compliance calibration data. The difficulty in determining the minimum stress intensity coefficient and the critical crack length is discussed.

  3. Further Characterization of an Active Clearance Control Concept

    NASA Technical Reports Server (NTRS)

    Taylor, Shawn C.; Steinetz, Bruce M.; Oswald, Jay J.

    2007-01-01

    A new test chamber and precision hydraulic actuation system were incorporated into an active clearance control (ACC) test rig at NASA Glenn Research Center. Using the improved system, a fast-acting, mechanically-actuated, ACC concept was evaluated at engine simulated temperatures and pressure differentials up to 1140 F and 120 psig, on the basis of secondary seal leakage and kinematic controllability. During testing, the ACC concept tracked a simulated flight clearance transient profile at 1140 F, 120 psig, with a maximum error of only 0.0012 in. Comparison of average dynamic leakage of the system with average static leakage did not show significant differences between the two operating conditions. Calculated effective clearance values for the rig were approximately 0.0002 in. at 120 psig, well below the industry specified effective clearance threshold of 0.001 in.

  4. Physical Activity and Obesity: Biomechanical and Physiological Key Concepts

    PubMed Central

    Nantel, Julie; Mathieu, Marie-Eve; Prince, François

    2011-01-01

    Overweight (OW) and obesity (OB) are often associated with low levels of physical activity. Physical activity is recommended to reduce excess body weight, prevent body weight regain, and decrease the subsequent risks of developing metabolic and orthopedic conditions. However, the impact of OW and OB on motor function and daily living activities must be taken into account. OW and OB are associated with musculoskeletal structure changes, decreased mobility, modification of the gait pattern, and changes in the absolute and relative energy expenditures for a given activity. While changes in the gait pattern have been reported at the ankle, knee, and hip, modifications at the knee level might be the most challenging for articular integrity. This review of the literature combines concepts and aims to provide insights into the prescription of physical activity for this population. Topics covered include the repercussions of OW and OB on biomechanical and physiological responses associated with the musculoskeletal system and daily physical activity. Special attention is given to the effect of OW and OB in youth during postural (standing) and various locomotor (walking, running, and cycling) activities. PMID:21113311

  5. Low Specific Activity materials concepts are being reevaluated

    SciTech Connect

    Rawl, R.R.

    1993-10-01

    Many types of radioactive low-level waste are classified, packaged, and transported as Low-Specific Activity (LSA) material. The transportation regulations allow LSA materials to be shipped in economical packagings and, under certain conditions, waives compliance with other detailed requirements such as labeling. The fundamental concepts which support the LSA category are being thoroughly reevaluated to determine the defensibility of the provisions. A series of national and international events are leading to the development of new dose models which are likely to fundamentally change the ways these materials are defined. Similar basis changes are likely for the packaging requirements applicable to these materials.

  6. Concept study on active shells driven by soft dielectric EAP

    NASA Astrophysics Data System (ADS)

    Lochmatter, Patrick; Kovacs, Gabor

    2007-04-01

    Adaptive structures are capable to change their shape in a smart way in order to "adapt" to variable external conditions. Active shell structures with large out-of-plane deformation potential may be used to generate an interaction between the structural shape and the environment. Exemplarily, such shell-like actuators may be utilized for the propulsion of vehicles through air or water. Among the electroactive polymers (EAPs) especially soft dielectric EAP are promising for driving shell-like actuators due to their huge active strain potential and intrinsic compliancy. The challenging task of this study was to explore the potential of the DE actuator technology for the design of shell-like actuators with the ability to perform complex out-of-plane deflections. We present and evaluate concepts for the design of active shell structures driven by soft dielectric EAP. Preliminary experiments were conducted for selected approaches in order to basically verify their principle of operation and to quantify their active out-of-plane deformation potential. These experiments showed that the so-called agonist-antagonist configuration, where pre-strained DE films are attached on both sides of a hinged backbone structure, holds good performance in terms of active out-of-plane deflections and forces.

  7. New semi-active damping concept using eddy currents

    NASA Astrophysics Data System (ADS)

    Sodano, Henry A.; Inman, Daniel J.; Belvin, W. K.

    2005-05-01

    A damping effect can be induced on a conductive structure that is vibrating in a magnetic field. This damping effect is caused by the eddy currents that are induced in the material due to a time varying magnetic field. The density of these currents is directly related to the velocity of the conductor in the magnetic field. However, once the currents are formed the internal resistance of the conductive material causes them to dissipate into heat, resulting in a removal of energy from the system and a damping effect. In a previous study, a permanent magnetic was fixed in a location such that the poling axis was perpendicular to the beam's motion and the radial magnetic flux was used to passively suppress the beam"s vibration. Using this passive damping concept and the idea that the damping force is directly related to the velocity of the conductor, a new semi-active damping mechanism will be created. This new damper will function by allowing the position of the magnet to change relative to the beam and thus allowing the net velocity between the two to be maximized and the damping force significantly increased. Using this concept, a model of both the passive and active portion of the system will be developed, allowing the beams response to be simulated. To verify the accuracy of this model, experiments will be performed that demonstrate both the accuracy of the model and the effectiveness of this semi-active control system for use in suppressing the transverse vibration of a structure.

  8. Control of active sites in flocculation: Concept of equivalent active sites''

    SciTech Connect

    Behl, S.; Moudgil, B.M. . Dept. of Materials Science and Engineering)

    1993-12-01

    Flocculation and dispersion of solids are strong functions of the amount and conformation of the adsorbed polymer. Regions of dispersion and flocculation of solids with particular polymer molecules may be deduced from saturation adsorption data. The concept of equivalent active sites'' is proposed to explain flocculation and dispersion behavior irrespective of the amount or conformation of the adsorbed polymer. The concept has been further extended to study the selective flocculation process.

  9. Digital Coordinates and Age for 3,869 Foraminifer Samples Collected by Chevron Petroleum Geologists in Washington and Oregon

    USGS Publications Warehouse

    West, William B.; Brabb, Earl E.; Malmborg, William T.; Parker, John M.

    2009-01-01

    The general location and age of more than 33,500 mostly foraminifer samples from Chevron Petroleum Company surface localities in California were provided by Brabb and Parker (2003, 2005). Malmborg and others (2008) provided digital latitude, longitude, and age for more than 13,000 of these samples. We provide here for the first time the digital latitude, longitude, and age for nearly 4,000 Chevron surface and auger samples in Washington and Oregon.

  10. Soil biological activity at European scale - two calculation concepts

    NASA Astrophysics Data System (ADS)

    Krüger, Janine; Rühlmann, Jörg

    2014-05-01

    The CATCH-C project aims to identify and improve the farm-compatibility of Soil Management Practices including to promote productivity, climate change mitigation and soil quality. The focus of this work concentrates on turnover conditions for soil organic matter (SOM). SOM is fundamental for the maintenance of quality and functions of soils while SOM storage is attributed a great importance in terms of climate change mitigation. The turnover conditions depend on soil biological activity characterized by climate and soil properties. To assess the turnover conditions two model concepts are applied: (I) Biological active time (BAT) regression approach derived from CANDY model (Franko & Oelschlägel 1995) expresses the variation of air temperature, precipitation and soil texture as a timescale and an indicator of biological activity for soil organic matter (SOM) turnover. (II) Re_clim parameter within the Introductory Carbon Balance Model (Andrén & Kätterer 1997) states the soil temperature and soil water to estimate soil biological activity. The modelling includes two strategies to cover the European scale and conditions. BAT was calculated on a 20x20 km grid basis. The European data sets of precipitation and air temperature (time period 1901-2000, monthly resolution), (Mitchell et al. 2004) were used to derive long-term averages. As we focus on agricultural areas we included CORINE data (2006) to extract arable land. The resulting BATs under co-consideration of the main soil textures (clay, silt, sand and loam) were investigated per environmental zone (ENZs, Metzger et al. 2005) that represents similar conditions for precipitation, temperature and relief to identify BAT ranges and hence turnover conditions for each ENZ. Re_clim was quantified by climatic time series of more than 250 weather stations across Europe presented by Klein Tank et al. (2002). Daily temperature, precipitation and potential evapotranspiration (maximal thermal extent) were used to calculate

  11. High Temperature Evaluation of an Active Clearance Control System Concept

    NASA Technical Reports Server (NTRS)

    Taylor, Shawn C.; Steinetz, Bruce M.; Oswald, Jay J.

    2006-01-01

    A mechanically actuated blade tip clearance control concept was evaluated in a nonrotating test rig to quantify secondary seal leakage at elevated temperatures. These tests were conducted to further investigate the feasibility of actively controlling the clearance between the rotor blade tips and the surrounding shroud seal in the high pressure turbine (HPT) section of a turbine engine. The test environment simulates the state of the back side of the HPT shroud seal with pressure differentials as high as 120 psig and temperatures up to 1000 F. As expected, static secondary seal leakage decreased with increasing temperature. At 1000 F, the test rig's calculated effective clearance (at 120 psig test pressure) was 0.0003 in., well within the industry specified effective clearance goal.

  12. How Active Learning Affects Student Understanding of Concepts in Electromagnetism

    NASA Astrophysics Data System (ADS)

    Belcher, John; Dori, Judy; Breslow, Lori

    2009-05-01

    We discuss the effects of the learning environment of the MIT TEAL project on student cognitive and affective outcomes in introductory electromagnetism. Our assessment included examining student conceptual understanding before and after studying electromagnetism in a media-rich environment. We developed pre-and posttests consisting of conceptual questions from standardized tests, as well as questions designed to assess the effect of visualizations and experiments. The research population consisted of 811 undergraduate students, consisting of small-and a large-scale experimental group and control group. The active learning students improved their conceptual understanding of the subject matter to a significantly higher extent than their control group peers. A subsequent longitudinal study indicates that the long-term effect of the TEAL course on student retention of concepts was significantly stronger than that of the traditional course.

  13. Cross-domain active learning for video concept detection

    NASA Astrophysics Data System (ADS)

    Li, Huan; Li, Chao; Shi, Yuan; Xiong, Zhang; Hauptmann, Alexander G.

    2011-08-01

    As video data from a variety of different domains (e.g., news, documentaries, entertainment) have distinctive data distributions, cross-domain video concept detection becomes an important task, in which one can reuse the labeled data of one domain to benefit the learning task in another domain with insufficient labeled data. In this paper, we approach this problem by proposing a cross-domain active learning method which iteratively queries labels of the most informative samples in the target domain. Traditional active learning assumes that the training (source domain) and test data (target domain) are from the same distribution. However, it may fail when the two domains have different distributions because querying informative samples according to a base learner that initially learned from source domain may no longer be helpful for the target domain. In our paper, we use the Gaussian random field model as the base learner which has the advantage of exploring the distributions in both domains, and adopt uncertainty sampling as the query strategy. Additionally, we present an instance weighting trick to accelerate the adaptability of the base learner, and develop an efficient model updating method which can significantly speed up the active learning process. Experimental results on TRECVID collections highlight the effectiveness.

  14. Seal Investigations of an Active Clearance Control System Concept

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.; Taylor, Shawn; Oswald, Jay; DeCastro, Jonathan A.

    2006-01-01

    In an effort to improve upon current thermal active clearance control methods, a first generation, fast-acting mechanically actuated, active clearance control system has been designed and installed into a non-rotating test rig. In order to harvest the benefit of tighter blade tip clearances, low-leakage seals are required for the actuated carrier segments of the seal shroud to prevent excessive leakage of compressor discharge (P3) cooling air. The test rig was designed and fabricated to facilitate the evaluation of these types of seals, identify seal leakage sources, and test other active clearance control system concepts. The objective of this paper is to present both experimental and analytical investigations into the nature of the face-seal to seal-carrier interface. Finite element analyses were used to examine face seal contact pressures and edge-loading under multiple loading conditions, varied E-seal positions and two new face seal heights. The analyses indicated that moving the E-seal inward radially and reducing face seal height would lead to more uniform contact conditions between the face seal and the carriers. Lab testing confirmed that moving the balance diameter inward radially caused a decrease in overall system leakage.

  15. Mean Flow and Noise Prediction for a Separate Flow Jet With Chevron Mixers

    NASA Technical Reports Server (NTRS)

    Koch, L. Danielle; Bridges, James; Khavaran, Abbas

    2004-01-01

    Experimental and numerical results are presented here for a separate flow nozzle employing chevrons arranged in an alternating pattern on the core nozzle. Comparisons of these results demonstrate that the combination of the WIND/MGBK suite of codes can predict the noise reduction trends measured between separate flow jets with and without chevrons on the core nozzle. Mean flow predictions were validated against Particle Image Velocimetry (PIV), pressure, and temperature data, and noise predictions were validated against acoustic measurements recorded in the NASA Glenn Aeroacoustic Propulsion Lab. Comparisons are also made to results from the CRAFT code. The work presented here is part of an on-going assessment of the WIND/MGBK suite for use in designing the next generation of quiet nozzles for turbofan engines.

  16. Androgynous rex - the utility of chevrons for determining the sex of crocodilians and non-avian dinosaurs.

    PubMed

    Erickson, Gregory M; Kristopher Lappin, A; Larson, Peter

    2005-01-01

    The sex of non-avian dinosaurs has been inferred on numerous occasions using a variety of anatomical criteria, but the efficacy of none has been proven. Nearly 50 years ago Romer suggested that the cranial-most or first chevron in the tails of some reptiles, including crocodilians, is sexually dimorphic. Recent work on this subject purportedly substantiated that the female first chevron articulates in a more caudal position than in males. Furthermore, it was concluded that this element is shorter in females. These phenotypic attributes theoretically provide a broader cloacal passageway for eggs by ovipositing females and a greater attachment area for male "penile retractor muscles". Because theropod dinosaurs such as Tyrannosaurus rex presumably show similar variation in chevron anatomy, the same criteria has been advocated for sexing dinosaurs. We tested the neontological model for the chevron sexual dimorphism hypothesis using a skeletonized growth series of American alligators (Alligator mississippiensis) of known sex. No statistical support for the hypothesis was found. Furthermore, analysis of a diversity of crocodilian taxa from museum collections revealed similar findings suggesting the alligator results are not taxon specific. Study of well-preserved tyrannosaurid dinosaurs in museum collections showed nearly invariant chevron positioning like that seen in crocodilians. This suggests the usefulness of chevron anatomy for sexing dinosaurs is tenuous.

  17. Electrooptical properties of the uniform chevron state of a ferroelectric smectic liquid crystal

    SciTech Connect

    Vorflusev, V.P.; Kosygina, M.A.; Shoshin, V.M.; Bobylev, Y.P.

    1995-12-31

    The influence of additives when introduced into the orienting agent on the orientation quality of the SmF phase of a liquid crystal (FLC) was studied. The conditions which allow bistable switching of the FLC with low spontaneous polarization P{sub s}(P{sub s} = 5 nCoul/cm{sup 2}) were determined. A model of smectic layers structure was suggested and the peculiarities of the optical transmission of thin chevron FLC cells were investigated. 8 figs., 5 refs.

  18. PIV Measurements of Chevrons on F400-Series Tactical Aircraft Nozzle Model

    NASA Technical Reports Server (NTRS)

    Bridges, James; Wernet, Mark P.; Frate, Franco C.

    2011-01-01

    Reducing noise of tactical jet aircraft has taken on fresh urgency as core engine technologies allow higher specific-thrust engines and as society become more concerned for the health of its military workforce. Noise reduction on this application has lagged the commercial field as incentives for quieting military aircraft have not been as strong as in their civilian counterparts. And noise reduction strategies employed on civilian engines may not be directly applicable due to the differences in exhaust system architecture and mission. For instance, the noise reduction technology of chevrons, examined in this study, will need to be modified to take into account the special features of tactical aircraft nozzles. In practice, these nozzles have divergent slats that are tied to throttle position, and at take off the jet flow is highly overexpanded as the nozzle is optimized for cruise altitude rather than sea level. In simple oil flow visualization experiments conducted at the onset of the current test program flow barely stays attached at end of nozzle at takeoff conditions. This adds a new twist to the design of chevrons. Upon reaching the nozzle exit the flow shrinks inward radially, meaning that for a chevron to penetrate the flow it must extend much farther away from the baseline nozzle streamline. Another wrinkle is that with a variable divergence angle on the nozzle, the effective penetration will differ with throttle position and altitude. The final note of realism introduced in these experiments was to simulate the manner in which bypass flow is bled into the nozzle wall in real engines to cool the nozzle, which might cause very fat boundary layer at exit. These factors, along with several other issues specific to the application of chevrons to convergent-divergent nozzles have been explored with particle image velocimetry measurements and are presented in this paper.

  19. Unstructured Large Eddy Simulations of Hot Supersonic Jets from a Chevron Nozzle

    NASA Astrophysics Data System (ADS)

    Brès, Guillaume; Nichols, Joseph; Lele, Sanjiva; Ham, Frank

    2012-11-01

    Large eddy simulations (LES) are performed for heated supersonic turbulent jets issued from a converging-diverging round nozzle with chevrons. The unsteady flow processes and shock/turbulence interactions are investigated with the unstructured compressible flow solver ``Charles'' developed at Cascade Technologies. In this study, the complex geometry of the nozzle and chevrons (12 counts, 6° penetration) are explicitly included in the computational domain using unstructured body-fitted mesh and adaptive grid refinement. Sound radiation from the jet is computed using an efficient frequency-domain implementation of the Ffowcs Williams-Hawkings equation. Noise predictions are compared to experimental measurements carried out at the United Technologies Research Center for the same nozzle and operating conditions. The initial blind comparisons show good agreement in terms of spectra shape and levels for both the near-field and far-field noise. The current results show that the simulations accurately capture the main flow and noise features, including the shock cells, broadband shock-associated noise and turbulent mixing noise. Additional analysis of the large database generated by the LES is ongoing, to further investigate jet noise sources and chevron effects. This work is supported by NAVAIR grant N68335-11-C-0026 managed by Dr. John Spyropoulos. The simulations were carried out at DoD supercomputer facilities in ERDC and AFRL as part of the HPC Challenge Project NAWCP30952C5.

  20. Analytical and computational studies on the vacuum performance of a chevron ejector

    NASA Astrophysics Data System (ADS)

    Kong, F. S.; Jin, Y. Z.; Kim, H. D.

    2016-02-01

    The effects of chevrons on the performance of a supersonic vacuum ejector-diffuser system are investigated numerically and evaluated theoretically in this work. A three-dimensional geometrical domain is numerically solved using a fully implicit finite volume scheme based on the unsteady Reynolds stress model. A one-dimensional mathematical model provides a useful tool to reveal the steady flow physics inside the vacuum ejector-diffuser system. The effects of the chevron nozzle on the generation of recirculation regions and Reynolds stress behaviors are studied and compared with those of a conventional convergent nozzle. The present performance parameters obtained from the simulated results and the mathematical results are validated with existing experimental data and show good agreement. Primary results show that the duration of the transient period and the secondary chamber pressure at a dynamic equilibrium state depend strongly on the primary jet conditions, such as inlet pressure and primary nozzle shape. Complicated oscillatory flow, generated by the unsteady movement of recirculation, finally settles into a dynamic equilibrium state. As a vortex generator, the chevron demonstrated its strong entrainment capacity to accelerate the starting transient flows to a certain extent and reduce the dynamic equilibrium pressure of the secondary chamber significantly.

  1. Design and fabrication of a MEMS chevron-type thermal actuator

    SciTech Connect

    Baracu, Angela; Voicu, Rodica; Müller, Raluca; Avram, Andrei; Pustan, Marius Chiorean, Radu Birleanu, Corina Dudescu, Cristian

    2015-02-17

    This paper presents the design and fabrication of a MEMS chevron-type thermal actuator. The device was designed for fabrication in the standard MEMS technology, where the topography of the upper layers depends on the patterns of structural and sacrificial layers underneath. The proposed actuator presents some advantages over usual thermal vertical chevron actuators by means of low operating voltages, high output force and linear movement without deformation of the shaft. The device simulations were done using COVENTOR software. The movement obtained by simulation was 12 μm, for a voltage of 0.2 V and the current intensity of 257 mA. The design optimizes the in-plane displacement by fixed anchors and beam inclination angle. Heating is provided by Joule dissipation. The material used for manufacture of chevron-based actuator was aluminum due to its thermal and mechanical properties. The release of the movable part was performed using isotropic dry etching by Reactive Ion Etching (RIE). A first inspection was achieved using Scanning Electron Microscope (SEM). In order to obtain the in-plane displacement we carried out electrical measurements. The thermal actuator can be used for a variety of optical and microassembling applications. This kind of thermal actuator could be integrated easily with other micro devices since its fabrication is compatible with the general semiconductor processes.

  2. Emergency response concept plan for Pueblo Depot Activity and vicinity

    SciTech Connect

    Carnes, S.A.; Sorensen, J.H.; Rogers, G.O.; Shumpert, B.L.; Miller, R.L.; Watson, A.P.; Chester, C.V.

    1989-10-01

    The continuous storage and disposal of the United States' unitary chemical stockpile, including that portion stored at Pueblo Depot Activity (PUDA) near Pueblo, Colorado, have the potential for accidental releases that could escape installation boundaries and pose a threat to civilian populations. The US Army, in conjunction with the Federal Emergency Management Agency and other federal agencies, is committed to implement an emergency preparedness program that will significantly reduce the probability of adverse effects from such releases. This concept plan, which is but a part of a comprehensive ongoing effort, provides a framework for initiating such a program for the PUDA stockpile. This report develops information and methodologies that bear on two major decisions for such a program -- determining emergency planning zones and selecting protective action strategies. These decisions are based on the hazards posed by the PUDA stockpile and its disposal. These hazards, in turn, are based largely on the distribution of potential accidental releases associated with interim storage and disposal activities and associated external events (e.g., earthquakes and airplane crashes), the distribution of natural features that can affect an agent release (topographical features and meteorological characteristics), and the distribution of people and resources (e.g., homes, schools, and hospitals) potentially affected by an accidental release. 21 refs., 9 figs., 12 tabs.

  3. Aerodynamic Characteristic of the Active Compliant Trailing Edge Concept

    NASA Astrophysics Data System (ADS)

    Nie, Rui; Qiu, Jinhao; Ji, Hongli; Li, Dawei

    2016-06-01

    This paper introduces a novel Morphing Wing structure known as the Active Compliant Trailing Edge (ACTE). ACTE structures are designed using the concept of “distributed compliance” and wing skins of ACTE are fabricated from high-strength fiberglass composites laminates. Through the relative sliding between upper and lower wing skins which are connected by a linear guide pairs, the wing is able to achieve a large continuous deformation. In order to present an investigation about aerodynamics and noise characteristics of ACTE, a series of 2D airfoil analyses are established. The aerodynamic characteristics between ACTE and conventional deflection airfoil are analyzed and compared, and the impacts of different ACTE structure design parameters on aerodynamic characteristics are discussed. The airfoils mentioned above include two types (NACA0012 and NACA64A005.92). The computing results demonstrate that: compared with the conventional plane flap airfoil, the morphing wing using ACTE structures has the capability to improve aerodynamic characteristic and flow separation characteristic. In order to study the noise level of ACTE, flow field analysis using LES model is done to provide noise source data, and then the FW-H method is used to get the far field noise levels. The simulation results show that: compared with the conventional flap/aileron airfoil, the ACTE configuration is better to suppress the flow separation and lower the overall sound pressure level.

  4. A new concept for active bistable twisting structures

    NASA Astrophysics Data System (ADS)

    Schultz, Marc R.

    2005-05-01

    A novel type of morphing structure capable of a large change in shape with a small energy input is discussed in this paper. The considered structures consist of two curved shells that are joined in a specific manner to form a bistable airfoil-like structure. The two stable shapes have a difference in axial twist, and the structure may be transformed between the stable shapes by a simple snap-through action. The benefit of a bistable structure of this type is that, if the stable shapes are operational shapes, power is needed only to transform the structure from one shape to another. The discussed structures could be used in aerodynamic applications such as morphing wings, or as aerodynamic control surfaces. The investigation discussed in this paper considers both experiment and finite-element analysis. Several graphite-epoxy composite and one steel device were created as proof-of-concept models. To demonstrate active control of these structures, piezocomposite actuators were applied to one of the composite structures and used to transform the structure between stable shapes. The analysis was used to compare the predicted shapes with the experimental shapes, and to study how changes to the geometric input values affected the shape and operational characteristics of the structures. The predicted shapes showed excellent agreement with the experimental shapes, and the results of the parametric study suggest that the shapes and the snap-through characteristics can be easily tailored to meet specific needs.

  5. Report on inspection of concerns regarding DOE`s evaluation of Chevron USA`s unsolicited proposal for the Elk Hills Naval Petroleum Reserve

    SciTech Connect

    1997-11-17

    An allegation was made to the Office of Inspector General (OIG) that the integrity of the Department of Energy`s (DOE) unsolicited proposal review process may have been compromised by the actions of a former Deputy Secretary of Energy and his Executive Assistant during the review of an unsolicited proposal received from Chevron U.S.A. Production Company (Chevron) in may 1993. The Chevron unsolicited proposal was for the management and operation of DOE`s Elk Hills Naval Petroleum Reserve (Elk Hills), located near Bakersfield, California. Chevron submitted the unsolicited proposal on May 19, 1993. DOE formally rejected Chevron`s unsolicited proposal in May 1995. Although Chevron`s unsolicited proposal was eventually rejected by DOE, the complainant specifically alleged that the {open_quotes}sanctity, integrity, and sensitivity{close_quotes} of the unsolicited proposal review process had been breached in meetings during the Fall of 1993 between Chevron officials, the Deputy Secretary of Energy (Deputy Secretary), and his Executive Assistant. Based on our review of the allegation, we identified the following issue as the focus of our inspection.

  6. A Framework of Active Learning by Concept Mapping

    ERIC Educational Resources Information Center

    Chen, Wang-Kun; Wang, Ping

    2012-01-01

    This study presents a student-centered teaching model based on concept mapping and problem-solving. The concept map is used as a tool to develop curriculum and evaluate teaching performance. Case-based teaching was implemented on the course of building energy conservation. The results of this study, which include teaching plans, evaluation tools,…

  7. Staff Conceptions of Curricular and Extracurricular Activities in Higher Education

    ERIC Educational Resources Information Center

    Clegg, Sue; Stevenson, Jacqueline; Willott, John

    2010-01-01

    This paper explores conceptions of curricular and extracurricular in UK higher education. Reporting on a case study of staff understandings of the extracurricular we argue that our data highlight the lack of debate about curricular matters. We found that there was considerable blurring of boundaries in conceptions of the curricular and…

  8. Unintended embodiment of concepts into percepts: sensory activation boosts attention for same-modality concepts in the attentional blink paradigm.

    PubMed

    Vermeulen, Nicolas; Mermillod, Martial; Godefroid, Jimmy; Corneille, Olivier

    2009-09-01

    This study shows that sensory priming facilitates reports of same-modality concepts in an attentional blink paradigm. Participants had to detect and report two target words (T1 and T2) presented for 53 ms each among a series of nonwords distractors at a frequency of up to 19 items per second. SOA between target words was set to 53 ms or 213 ms, with reduced attention expected for T2 under the longer SOA (attentional blink) and for T1 under the shorter SOA (lag-1 sparing). These effects were found but reduced when the sensory modality of the concepts matched that of a sensory stimulation occurring prior to the detection trial. Hence, sensory activation increased report for same-modality concepts. This finding reveals that grounded cognition effects (1) are involved in conceptual processing as soon as a word has reached the point of lexical identification and (2) occur independent of intentional access to sensory properties of concepts. PMID:19576578

  9. Active Noise Control of Radiated Noise from Jets Originating NASA

    NASA Technical Reports Server (NTRS)

    Doty, Michael J.; Fuller, Christopher R.; Schiller, Noah H.; Turner, Travis L.

    2013-01-01

    The reduction of jet noise using a closed-loop active noise control system with highbandwidth active chevrons was investigated. The high frequency energy introduced by piezoelectrically-driven chevrons was demonstrated to achieve a broadband reduction of jet noise, presumably due to the suppression of large-scale turbulence. For a nozzle with one active chevron, benefits of up to 0.8 dB overall sound pressure level (OASPL) were observed compared to a static chevron nozzle near the maximum noise emission angle, and benefits of up to 1.9 dB OASPL were observed compared to a baseline nozzle with no chevrons. The closed-loop actuation system was able to effectively reduce noise at select frequencies by 1-3 dB. However, integrated OASPL did not indicate further reduction beyond the open-loop benefits, most likely due to the preliminary controller design, which was focused on narrowband performance.

  10. Development and Demonstration of Active Noise Control Concepts

    NASA Technical Reports Server (NTRS)

    Kraft, R.; Hu, Z.; Sommerfeldt, S.; Walker, B.; Hersh, A.; Luo, H.; Spencer, M.; Hallman, D.; Mitchell, C.; Sutliff, D.

    2000-01-01

    This report details design methods for and feasibility of an Active Noise Control (ANC) system using flush-wall-mounted sensors and actuators to reduce turbofan engine rotor-stator interaction noise. ANC concepts capable of suppressing discrete-tone spinning modes containing several cut-on radial mode were identified, developed analytically, and evaluated. Separate ANC systems that suppressed at least three radial modes in a cylindrical inlet duct and three radial modes in an exhaust annulus were developed. These designs resulted in inlet duct and exhaust duct tests that were performed at NASA on the 4-ft ANC Fan in the NASA Glenn AAPL facility. Effective suppression of 2-BPF spinning mode m = 2 tone noise was achieved over a range of fan speeds 1800 to 2450 rpm, where up to 4 radials were present. In the inlet duct, up to 12 dB reduction was obtained for 3 radial modes, and up to 4 dB was obtained with 4 radial modes. In the exhaust duct, up to 15 dB PWL reduction was obtained with either two or three radial modes present. Thus, the ability to suppress multiple radial modes for tones in both the inlet and exhaust ducts has been successfully demonstrated. Implications of ANC system design requirements on installation and system integration issues for ANC systems capable of suppressing higher order radial mode content when applied to a 767 using twin CF6 engines were evaluated analytically. The analytical results indicated an ANC system must be part of an integrated design to be effective.

  11. Redefining the concept of protease-activated receptors: cathepsin S evokes itch via activation of Mrgprs

    PubMed Central

    Reddy, Vemuri B.; Sun, Shuohao; Azimi, Ehsan; Elmariah, Sarina B.; Dong, Xinzhong; Lerner, Ethan A.

    2015-01-01

    Sensory neurons expressing Mas-related G protein coupled receptors (Mrgprs) mediate histamine-independent itch. We show that the cysteine protease cathepsin S activates MrgprC11 and evokes receptor-dependent scratching in mice. In contrast to its activation of conventional protease-activated receptors, cathepsin S mediated activation of MrgprC11 did not involve the generation of a tethered ligand. We demonstrate further that different cysteine proteases selectively activate specific mouse and human Mrgpr family members. This expansion of our understanding by which proteases interact with GPCRs redefines the concept of what constitutes a protease-activated receptor. The findings also implicate proteases as ligands to members of this orphan receptor family while providing new insights into how cysteine proteases contribute to itch. PMID:26216096

  12. Foundations of Children's Self-Concepts about Everyday Activities: Identities and Comparative Contexts

    ERIC Educational Resources Information Center

    Fisher, Laurel

    2014-01-01

    Children's motivations to engage in everyday activities draw on their experiences in thinking of oneself and the activities. In theory, these personal and social realities provide the complex foundations of self-concepts. The aim of this project was to define the foundations of children's self-concepts about everyday activities; to focus…

  13. Using Laboratory Activities Enhanced with Concept Cartoons to Support Progression in Students' Understanding of Acid-Base Concepts

    ERIC Educational Resources Information Center

    Ozmen, Haluk; Demircioglu, Gokhan; Burhan, Yasemin; Naseriazar, Akbar; Demircioglu, Hulya

    2012-01-01

    The aim of this study is to examine the effectiveness of an intervention based on a series of laboratory activities enhanced with concept cartoons. The purpose of the intervention was to enhance students' understanding of acid-base chemistry for eight grade students' from two classes in a Turkish primary school. A pretest-posttest non-equivalent…

  14. Three-dimensional analysis of chevron-notched specimens by boundary integral method

    NASA Technical Reports Server (NTRS)

    Mendelson, A.; Ghosn, L.

    1983-01-01

    The chevron-notched short bar and short rod specimens was analyzed by the boundary integral equations method. This method makes use of boundary surface elements in obtaining the solution. The boundary integral models were composed of linear triangular and rectangular surface segments. Results were obtained for two specimens with width to thickness ratios of 1.45 and 2.00 and for different crack length to width ratios ranging from 0.4 to 0.7. Crack opening displacement and stress intensity factors determined from displacement calculations along the crack front and compliance calculations were compared with experimental values and with finite element analysis.

  15. Learning the Electric Field Concept as Oriented Research Activity

    ERIC Educational Resources Information Center

    Furio, C.; Guisasola, J.; Almudi, J. M.; Ceberio, M.

    2003-01-01

    This work is grounded in a constructivistic conception of the learning of science, more particularly on the model known as teaching-learning as oriented research. In accordance with this theoretical basis we have developed an empirical research project to investigate the teaching of electrostatics in high schools. The designs developed have…

  16. Evolution & Phylogenetic Analysis: Classroom Activities for Investigating Molecular & Morphological Concepts

    ERIC Educational Resources Information Center

    Franklin, Wilfred A.

    2010-01-01

    In a flexible multisession laboratory, students investigate concepts of phylogenetic analysis at both the molecular and the morphological level. Students finish by conducting their own analysis on a collection of skeletons representing the major phyla of vertebrates, a collection of primate skulls, or a collection of hominid skulls.

  17. Evolution of chevron folds by profile shape changes: comparison between multilayer deformation experiments and folds of the Bendigo-Castlemaine goldfields, Australia

    NASA Astrophysics Data System (ADS)

    Fowler, T. J.; Winsor, C. N.

    1996-06-01

    The Bendigo-Castlemaine goldfields lie within the well-known chevron-folded Ordovician turbidites of Victoria, Australia. Detailed re-examination of surface and subsurface maps indicates that there are other common fold shapes (boxfolds and flat-topped folds with subsidiary hinges) which are enclosed within chevron folded layers and are traceable into them. Plasticine multilayer experiments were performed to examine the fold profile shape evolution of chevrons and associated folds. In the experiments chevrons evolved from sinusoidal folds or boxfolds. Sinusoidal folds became chevrons mainly via hinge sharpening, while boxfolds evolved into chevrons via hinge migration and fusion of the hinges. For boxfolds, hinge migration rates controlled rates of limb steepening versus median segment (i.e., the flat top of the boxfold) length reduction during bulk shortening. Periodic slowing or "jamming" of hinge migration led to stepwise) limb-dip increases, and buckling of median segments producing analogous fold styles to those seen in the Bendigo-Castlemaine folds. Limb steepening in a boxfolded multilayer must lead to dilations spanning the median segment and/or curving of boxfold axial planes. The latter dilations experience the same shape changes as their enclosing folded layers. In nature such dilation may be represented by bedding-parallel veins which are subsequently incorporated onto chevron limbs as a result of hinge migration. Thus bedding-parallel veins which are continuous over chevron hinges and are folded in the hinge zones need not be pre-folding or early-folding.

  18. Conceptions of Effective Teaching and Perceived Use of Computer Technologies in Active Learning Classrooms

    ERIC Educational Resources Information Center

    Gebre, Engida; Saroyan, Alenoush; Aulls, Mark W.

    2015-01-01

    This paper examined professors' conceptions of effective teaching in the context of a course they were teaching in active learning classrooms and how the conceptions related to the perceived role and use of computers in their teaching. We interviewed 13 professors who were teaching in active learning classrooms in winter 2011 in a large research…

  19. Comparing Two Forms of Concept Map Critique Activities to Facilitate Knowledge Integration Processes in Evolution Education

    ERIC Educational Resources Information Center

    Schwendimann, Beat A.; Linn, Marcia C.

    2016-01-01

    Concept map activities often lack a subsequent revision step that facilitates knowledge integration. This study compares two collaborative critique activities using a Knowledge Integration Map (KIM), a form of concept map. Four classes of high school biology students (n?=?81) using an online inquiry-based learning unit on evolution were assigned…

  20. Impact of chevron spacing and asymmetric distribution on supersonic jet acoustics and flow

    NASA Astrophysics Data System (ADS)

    Heeb, N.; Gutmark, E.; Kailasanath, K.

    2016-05-01

    An experimental investigation into the effect of chevron spacing and distribution on supersonic jets was performed. Cross-stream and streamwise particle imaging velocimetry measurements were used to relate flow field modification to sound field changes measured by far-field microphones in the overexpanded, ideally expanded, and underexpanded regimes. Drastic modification of the jet cross-section was achieved by the investigated configurations, with both elliptic and triangular shapes attained downstream. Consequently, screech was nearly eliminated with reductions in the range of 10-25 dB depending on the operating condition. Analysis of the streamwise velocity indicated that both the mean shock spacing and strength were reduced resulting in an increase in the broadband shock associated noise spectral peak frequency and a reduction in the amplitude, respectively. Maximum broadband shock associated noise amplitude reductions were in the 5-7 dB range. Chevron proximity was found to be the primary driver of peak vorticity production, though persistence followed the opposite trend. The integrated streamwise vorticity modulus was found to be correlated with peak large scale turbulent mixing noise reduction, though optimal overall sound pressure level reductions did not necessarily follow due to the shock/fine scale mixing noise sources. Optimal large scale mixing noise reductions were in the 5-6 dB range.

  1. Change in First Metatarsal Length After Proximal and Distal Chevron Osteotomies for Hallux Valgus Deformity.

    PubMed

    Lee, Jun Young; Lee, Yeon Soo; Song, Kyoung Chul; Choi, Kwi Youn

    2015-01-01

    The present study assessed the changes in the length of the first metatarsal bone after performing proximal chevron metatarsal osteotomy (PCMO) or distal Chevron metatarsal osteotomy (DCMO) for patients with hallux valgus deformity. A total of 60 patients with moderate-to-severe hallux valgus deformity from July 2009 to July 2011 were randomly divided into the PCMO and DCMO groups, with 30 patients in each group. The distal soft tissue procedure was performed in the same method for both groups. Measurements were performed preoperatively, postoperatively, and at the last follow-up visit at 6.1 ± 0.8 months. The postoperative length change with respect to the preoperative length was 0.7 ± 2.5 mm and -0.7 ± 5.1 mm for the PCMO and DCMO groups, respectively, with a slight lengthening of the first metatarsal bone in the PCMO group and a shortening in the DCMO group (p < .01). The follow-up length change with respect to the preoperative length was -2.1 ± 3.0 mm and -4.4 ± 2.2 mm for the PCMO and DCMO groups, respectively, demonstrating a clear shortening of the first metatarsal length at the last follow-up point in the DCMO group (p < .01).When DCMO and the distal soft tissue procedure were performed, significant shortening was found at 6 months of follow-up.

  2. An Analysis of Model Scale Data Transformation to Full Scale Flight Using Chevron Nozzles

    NASA Technical Reports Server (NTRS)

    Brown, Clifford; Bridges, James

    2003-01-01

    Ground-based model scale aeroacoustic data is frequently used to predict the results of flight tests while saving time and money. The value of a model scale test is therefore dependent on how well the data can be transformed to the full scale conditions. In the spring of 2000, a model scale test was conducted to prove the value of chevron nozzles as a noise reduction device for turbojet applications. The chevron nozzle reduced noise by 2 EPNdB at an engine pressure ratio of 2.3 compared to that of the standard conic nozzle. This result led to a full scale flyover test in the spring of 2001 to verify these results. The flyover test confirmed the 2 EPNdB reduction predicted by the model scale test one year earlier. However, further analysis of the data revealed that the spectra and directivity, both on an OASPL and PNL basis, do not agree in either shape or absolute level. This paper explores these differences in an effort to improve the data transformation from model scale to full scale.

  3. Computational and Experimental Flow Field Analyses of Separate Flow Chevron Nozzles and Pylon Interaction

    NASA Technical Reports Server (NTRS)

    Massey, Steven J.; Thomas, Russell H.; AbdolHamid, Khaled S.; Elmiligui, Alaa A.

    2003-01-01

    A computational and experimental flow field analyses of separate flow chevron nozzles is presented. The goal of this study is to identify important flow physics and modeling issues required to provide highly accurate flow field data which will later serve as input to the Jet3D acoustic prediction code. Four configurations are considered: a baseline round nozzle with and without a pylon, and a chevron core nozzle with and without a pylon. The flow is simulated by solving the asymptotically steady, compressible, Reynolds-averaged Navier-Stokes equations using an implicit, up-wind, flux-difference splitting finite volume scheme and standard two-equation kappa-epsilon turbulence model with a linear stress representation and the addition of a eddy viscosity dependence on total temperature gradient normalized by local turbulence length scale. The current CFD results are seen to be in excellent agreement with Jet Noise Lab data and show great improvement over previous computations which did not compensate for enhanced mixing due to high temperature gradients.

  4. 77 FR 66597 - Chevron U.S.A. Inc.; Application for Blanket Authorization To Export Previously Imported...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-06

    ... from foreign sources in an amount up to the equivalent of 72 billion cubic feet (Bcf) of natural gas on..., DOE/FE Order No. 3113 granted Chevron blanket authorization to import LNG up to the equivalent of 800 Bcf of natural gas from various international sources for a two-year period beginning on August...

  5. 75 FR 53284 - Chevron Keystone Gas Storage, LLC; Bridgeline Holdings, L.P.; New York State Electric & Gas...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-31

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PR10-81-000; Docket No. PR10-82-000; Docket No. PR10-83-000 (Not Consolidated)] Chevron Keystone Gas Storage, LLC; Bridgeline Holdings, L.P.; New York State Electric & Gas Corporation; Notice of...

  6. An Activity for Demonstrating the Concept of a Neural Circuit

    ERIC Educational Resources Information Center

    Kreiner, David S.

    2012-01-01

    College students in two sections of a general psychology course participated in a demonstration of a simple neural circuit. The activity was based on a neural circuit that Jeffress proposed for localizing sounds. Students in one section responded to a questionnaire prior to participating in the activity, while students in the other section…

  7. Active management of food allergy: an emerging concept.

    PubMed

    Anagnostou, Katherine; Stiefel, Gary; Brough, Helen; du Toit, George; Lack, Gideon; Fox, Adam T

    2015-04-01

    IgE-mediated food allergies are common and currently there is no cure. Traditionally, management has relied upon patient education, food avoidance and the provision of an emergency medication plan. Despite this, food allergy can significantly impact on quality of life. Therefore, in recent years, evolving research has explored alternative management strategies. A more active approach to management is being adopted, which includes early introduction of potentially allergenic foods, anticipatory testing, active monitoring, desensitisation to food allergens and active risk management. This review will discuss these areas in turn.

  8. Look Around You. A Primary Student Activity Book Introducing Basic Environmental Concepts.

    ERIC Educational Resources Information Center

    Starkey, Sharon

    This activity book, designed for student use, introduces environmental concepts to the primary student. The basic concept around which the guide is developed is the idea that the environment contains many interdependent things. Water, wind, clouds, non-living objects, plants, animals, and pollution are dealt with as part of the primary student's…

  9. Modeling of Word Translation: Activation Flow from Concepts to Lexical Items

    ERIC Educational Resources Information Center

    Roelofs, Ardi; Dijkstra, Ton; Gerakaki, Svetlana

    2013-01-01

    Whereas most theoretical and computational models assume a continuous flow of activation from concepts to lexical items in spoken word production, one prominent model assumes that the mapping of concepts onto words happens in a discrete fashion (Bloem & La Heij, 2003). Semantic facilitation of context pictures on word translation has been taken to…

  10. "Dear Ann ..." An Activity for Synthesizing and Applying Interpersonal Concepts

    ERIC Educational Resources Information Center

    Brule, Nancy J.

    2007-01-01

    All students struggle with interpersonal based problems, be it a troublesome roommate, problems with a partner, conflict with a significant other, or relational issues with parents or children. The interpersonal communication classroom can be enhanced by discussing these problems and experiences. This article presents an activity that aims to (1)…

  11. Creative Activity in Conception of Sustainable Development Education

    ERIC Educational Resources Information Center

    Slahova, Aleksandra; Savvina, Jolanta; Cacka, Maris; Volonte, Ilze

    2007-01-01

    Purpose: The purpose of this paper is to reflect on the stages in the development of creative activity considering the distinctive features of all stages and the modes of dynamics of the development of a creative person. Design/methodology/approach: The paper analyses scientific investigations and pedagogical experiences in order to develop the…

  12. Community Information and Services Centers: Concepts for Activation.

    ERIC Educational Resources Information Center

    Hopkins, Cleve

    An experimental program based on a study by the Department of Housing and Urban Development was activated to deliver services to urban residents via automated communications technology. Designed to contribute to improvement in the quality of life, the program of a Community Information and Services Center (CISC) included: outreach programs, i.e.,…

  13. EMF Monitoring—Concepts, Activities, Gaps and Options

    PubMed Central

    Dürrenberger, Gregor; Fröhlich, Jürg; Röösli, Martin; Mattsson, Mats-Olof

    2014-01-01

    Exposure to electromagnetic fields (EMF) is a cause of concern for many people. The topic will likely remain for the foreseeable future on the scientific and political agenda, since emissions continue to change in characteristics and levels due to new infrastructure deployments, smart environments and novel wireless devices. Until now, systematic and coordinated efforts to monitor EMF exposure are rare. Furthermore, virtually nothing is known about personal exposure levels. This lack of knowledge is detrimental for any evidence-based risk, exposure and health policy, management and communication. The main objective of the paper is to review the current state of EMF exposure monitoring activities in Europe, to comment on the scientific challenges and deficiencies, and to describe appropriate strategies and tools for EMF exposure assessment and monitoring to be used to support epidemiological health research and to help policy makers, administrators, industry and consumer representatives to base their decisions and communication activities on facts and data. PMID:25216256

  14. Evaluation of an Active Clearance Control System Concept

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.; Lattime, Scott B.; Taylor, Shawn; DeCastro, Jonathan A.; Oswald, Jay; Melcher, Kevin J.

    2005-01-01

    Reducing blade tip clearances through active tip clearance control in the high pressure turbine can lead to significant reductions in emissions and specific fuel consumption as well as dramatic improvements in operating efficiency and increased service life. Current engines employ scheduled cooling of the outer case flanges to reduce high pressure turbine tip clearances during cruise conditions. These systems have relatively slow response and do not use clearance measurement, thereby forcing cold build clearances to set the minimum clearances at extreme operating conditions (e.g., takeoff, reburst) and not allowing cruise clearances to be minimized due to the possibility of throttle transients (e.g., step change in altitude). In an effort to improve upon current thermal methods, a first generation mechanically-actuated active clearance control (ACC) system has been designed and fabricated. The system utilizes independent actuators, a segmented shroud structure, and clearance measurement feedback to provide fast and precise active clearance control throughout engine operation. Ambient temperature performance tests of this first generation ACC system assessed individual seal component leakage rates and both static and dynamic overall system leakage rates. The ability of the nine electric stepper motors to control the position of the seal carriers in both open- and closed-loop control modes for single and multiple cycles was investigated. The ability of the system to follow simulated engine clearance transients in closed-loop mode showed the system was able to track clearances to within a tight tolerance ( 0.001 in. error).

  15. Evaluation of an Active Clearance Control System Concept

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.; Lattime, Scott B.; DeCastro, Jonathan A.; Oswald, Jay; Melcher, Kevin J.

    2005-01-01

    Reducing blade tip clearances through active tip clearance control in the high pressure turbine can lead to significant reductions in emissions and specific fuel consumption as well as dramatic improvements in operating efficiency and increased service life. Current engines employ scheduled cooling of the outer case flanges to reduce high pressure turbine tip clearances during cruise conditions. These systems have relatively slow response and do not use clearance measurement, thereby forcing cold build clearances to set the minimum clearances at extreme operating conditions (e.g., takeoff, reburst) and not allowing cruise clearances to be minimized due to the possibility of throttle transients (e.g., step change in altitude). In an effort to improve upon current thermal methods, a first generation mechanically-actuated active clearance control (ACC) system has been designed and fabricated. The system utilizes independent actuators, a segmented shroud structure, and clearance measurement feedback to provide fast and precise active clearance control throughout engine operation. Ambient temperature performance tests of this first generation ACC system assessed individual seal component leakage rates and both static and dynamic overall system leakage rates. The ability of the nine electric stepper motors to control the position of the seal carriers in both open- and closed-loop control modes for single and multiple cycles was investigated. The ability of the system to follow simulated engine clearance transients in closed-loop mode showed the system was able to track clearances to within a tight tolerance (0.001 in. error).

  16. The Use of Energizers to Reinforce Nutrition Concepts and Encourage Physical Activity

    ERIC Educational Resources Information Center

    Lovett, Kathleen; Johnson, Betsy; Caskey, Mary; Pleasants, Christopher; Hurtado, G. Ali

    2014-01-01

    Given the importance of including daily physical activity as a part of a healthy lifestyle, Extension educators should do as much as they can to incorporate physical activity into their educational programming. A University of Minnesota Extension team has created a set of activities that incorporate motion to reinforce nutrition concepts, which…

  17. Women, Physical Activity, and Quality of Life: Self-concept as a Mediator.

    PubMed

    Gonzalo Silvestre, Tamara; Ubillos Landa, Silvia

    2016-02-22

    The objectives of this research are: (a) analyze the incremental validity of physical activity's (PA) influence on perceived quality of life (PQL); (b) determine if PA's predictive power is mediated by self-concept; and (c) study if results vary according to a unidimensional or multidimensional approach to self-concept measurement. The sample comprised 160 women from Burgos, Spain aged 18 to 45 years old. Non-probability sampling was used. Two three-step hierarchical regression analyses were applied to forecast PQL. The hedonic quality-of-life indicators, self-concept, self-esteem, and PA were included as independent variables. The first regression analysis included global self-concept as predictor variable, while the second included its five dimensions. Two mediation analyses were conducted to see if PA's ability to predict PQL was mediated by global and physical self-concept. Results from the first regression shows that self-concept, satisfaction with life, and PA were significant predictors. PA slightly but significantly increased explained variance in PQL (2.1%). In the second regression, substituting global self-concept with its five constituent factors, only the physical dimension and satisfaction with life predicted PQL, while PA ceased to be a significant predictor. Mediation analysis revealed that only physical self-concept mediates the relationship between PA and PQL (z = 1.97, p < .050), and not global self-concept. Physical self-concept was the strongest predictor and approximately 32.45 % of PA's effect on PQL was mediated by it. This study's findings support a multidimensional view of self-concept, and represent a more accurate image of the relationship between PQL, PA, and self-concept.

  18. Women, Physical Activity, and Quality of Life: Self-concept as a Mediator.

    PubMed

    Gonzalo Silvestre, Tamara; Ubillos Landa, Silvia

    2016-01-01

    The objectives of this research are: (a) analyze the incremental validity of physical activity's (PA) influence on perceived quality of life (PQL); (b) determine if PA's predictive power is mediated by self-concept; and (c) study if results vary according to a unidimensional or multidimensional approach to self-concept measurement. The sample comprised 160 women from Burgos, Spain aged 18 to 45 years old. Non-probability sampling was used. Two three-step hierarchical regression analyses were applied to forecast PQL. The hedonic quality-of-life indicators, self-concept, self-esteem, and PA were included as independent variables. The first regression analysis included global self-concept as predictor variable, while the second included its five dimensions. Two mediation analyses were conducted to see if PA's ability to predict PQL was mediated by global and physical self-concept. Results from the first regression shows that self-concept, satisfaction with life, and PA were significant predictors. PA slightly but significantly increased explained variance in PQL (2.1%). In the second regression, substituting global self-concept with its five constituent factors, only the physical dimension and satisfaction with life predicted PQL, while PA ceased to be a significant predictor. Mediation analysis revealed that only physical self-concept mediates the relationship between PA and PQL (z = 1.97, p < .050), and not global self-concept. Physical self-concept was the strongest predictor and approximately 32.45 % of PA's effect on PQL was mediated by it. This study's findings support a multidimensional view of self-concept, and represent a more accurate image of the relationship between PQL, PA, and self-concept. PMID:26898406

  19. Active Flow Effectors for Noise and Separation Control

    NASA Technical Reports Server (NTRS)

    Turner, Travis L.

    2011-01-01

    New flow effector technology for separation control and enhanced mixing is based upon shape memory alloy hybrid composite (SMAHC) technology. The technology allows for variable shape control of aircraft structures through actively deformable surfaces. The flow effectors are made by embedding shape memory alloy actuator material in a composite structure. When thermally actuated, the flow effector def1ects into or out of the flow in a prescribed manner to enhance mixing or induce separation for a variety of applications, including aeroacoustic noise reduction, drag reduction, and f1ight control. The active flow effectors were developed for noise reduction as an alternative to fixed-configuration effectors, such as static chevrons, that cannot be optimized for airframe installation effects or variable operating conditions and cannot be retracted for off-design or fail-safe conditions. Benefits include: Increased vehicle control, overall efficiency, and reduced noise throughout all f1ight regimes, Reduced flow noise, Reduced drag, Simplicity of design and fabrication, Simplicity of control through direct current stimulation, autonomous re sponse to environmental heating, fast re sponse, and a high degree of geometric stability. The concept involves embedding prestrained SMA actuators on one side of the chevron neutral axis in order to generate a thermal moment and def1ect the structure out of plane when heated. The force developed in the host structure during def1ection and the aerodynamic load is used for returning the structure to the retracted position. The chevron design is highly scalable and versatile, and easily affords active and/or autonomous (environmental) control. The technology offers wide-ranging market applications, including aerospace, automotive, and any application that requires flow separation or noise control.

  20. The concept of the mechanically active guideway as a novel approach to maglev

    NASA Technical Reports Server (NTRS)

    Horwath, T. G.

    1992-01-01

    A maglev system that is suitable for operation in the United States will have to meet unique requirements which determine the major systems characteristics. Maglev configurations presently developed in Germany and Japan are based on conventional maglev concepts and as such do not meet all of the requirements. A novel maglev guideway concept is introduced as a solution. This concept, the mechanically active guideway, is articulated in three degrees of freedom and assumes system functions which normally reside in the maglev vehicle. The mechanically active guideway contains spatially distributed actuators which are energized under computer control at the time of vehicle passage to achieve bank angle adjustment and ride quality control. A typical realization of the concept is outlined.

  1. Effects of subcritical crack growth on fracture toughness of ceramics assessed in chevron-notched three-point bend tests

    NASA Technical Reports Server (NTRS)

    Chao, L. Y.; Singh, D.; Shetty, D. K.

    1988-01-01

    A numerical computational study was carried out to assess the effects of subcritical crack growth on crack stability in the chevron-notched three-point bend specimens. A power-law relationship between the subcritical crack velocity and the applied stress intensity were used along with compliance and stress-intensity relationships for the chevron-notched bend specimen to calculate the load response under fixed deflection rate and a machine compliance. The results indicate that the maximum load during the test occurs at the same crack length for all the deflection rates; the maximum load, however, is dependent on the deflection rate for rates below the critical rate. The resulting dependence of the apparent fracture toughness on the deflection rate is compared to experimental results on soda-lime glass and polycrystalline alumina.

  2. The Evolution of a Collaborative Concept Mapping Activity for Undergraduate Microbiology Students

    ERIC Educational Resources Information Center

    Kinchin, Ian M.; De-Leij, Frans A. A. M.; Hay, David B.

    2005-01-01

    Concept mapping activities were trialed over a 2 year period as part of an undergraduate microbiology course. This paper describes this developmental process and offers insight into the most beneficial ways of employing this tool in a higher education setting. The aim was to investigate the use of mapping activities to improve students'…

  3. An Activity-Based Learning Approach for Key Geographical Information Systems (GIS) Concepts

    ERIC Educational Resources Information Center

    Srivastava, Sanjeev Kumar; Tait, Cynthia

    2012-01-01

    This study presents the effect of active learning methods of concepts in geographical information systems where students participated in a series of interlocked learning experiences. These activities spanned several teaching weeks and involved the creation of a hand drawn map that was scanned and geo-referenced with locations' coordinates derived…

  4. Comparing Computer-Supported Dynamic Modeling and "Paper & Pencil" Concept Mapping Technique in Students' Collaborative Activity

    ERIC Educational Resources Information Center

    Komis, Vassilis; Ergazaki, Marida; Zogza, Vassiliki

    2007-01-01

    This study aims at highlighting the collaborative activity of two high school students (age 14) in the cases of modeling the complex biological process of plant growth with two different tools: the "paper & pencil" concept mapping technique and the computer-supported educational environment "ModelsCreator". Students' shared activity in both cases…

  5. Self-Conception and Life Satisfaction: Integrating Aged Subculture and Activity Theory.

    ERIC Educational Resources Information Center

    McClelland, Kent A.

    1982-01-01

    Integrates the traditional activity theory explanation of adjustment to aging with the aged subculture theory advanced by Rose. A path model to data from two subsamples of older adults. Self-conception is shown to be an important intervening variable between social activity and life satisfaction. (Author)

  6. Student Engagement with Artefacts and Scientific Ideas in a Laboratory and a Concept-Mapping Activity

    NASA Astrophysics Data System (ADS)

    Mikael Hamza, Karim; Wickman, Per-Olof

    2013-09-01

    The purpose of this study is to use a comparative approach to scrutinize the common assumption that certain school science activities are theoretical and therefore particularly suited for engaging students with scientific ideas, whereas others are practical and, thus, not equally conducive to engagement with scientific ideas. We compared two school science activities, one (laboratory work) that is commonly regarded as focusing attention on artefacts that may distract students from central science concepts and the other (concept mapping) that is thought to make students focus directly on these concepts. We observed students in either a laboratory activity about real galvanic cells or a concept-mapping activity about idealized galvanic cells. We used a practical epistemology analysis to compare the two activities regarding students' actions towards scientific ideas and artefacts. The comparison revealed that the two activities, despite their alleged differences along the theory-practice scale, primarily resulted in similar student actions. For instance, in both activities, students interacted extensively with artefacts and, to a lesser extent, with scientific ideas. However, only occasionally did students establish any explicit continuity between artefacts and scientific ideas. The findings indicate that some of the problems commonly considered to be unique for school science practical work may indeed be a feature of school science activities more generally.

  7. Predicting brain activation patterns associated with individual lexical concepts based on five sensory-motor attributes

    PubMed Central

    Fernandino, Leonardo; Humphries, Colin J.; Seidenberg, Mark S.; Gross, William L.; Conant, Lisa L.; Binder, Jeffrey R.

    2015-01-01

    While major advances have been made in uncovering the neural processes underlying perceptual representations, our grasp of how the brain gives rise to conceptual knowledge remains relatively poor. Recent work has provided strong evidence that concepts rely, at least in part, on the same sensory and motor neural systems through which they were acquired, but it is still unclear whether the neural code for concept representation uses information about sensory-motor features to discriminate between concepts. In the present study, we investigate this question by asking whether an encoding model based on five semantic attributes directly related to sensory-motor experience – sound, color, visual motion, shape, and manipulation – can successfully predict patterns of brain activation elicited by individual lexical concepts. We collected ratings on the relevance of these five attributes to the meaning of 820 words, and used these ratings as predictors in a multiple regression model of the fMRI signal associated with the words in a separate group of participants. The five resulting activation maps were then combined by linear summation to predict the distributed activation pattern elicited by a novel set of 80 test words. The encoding model predicted the activation patterns elicited by the test words significantly better than chance. As expected, prediction was successful for concrete but not for abstract concepts. Comparisons between encoding models based on different combinations of attributes indicate that all five attributes contribute to the representation of concrete concepts. Consistent with embodied theories of semantics, these results show, for the first time, that the distributed activation pattern associated with a concept combines information about different sensory-motor attributes according to their respective relevance. Future research should investigate how additional features of phenomenal experience contribute to the neural representation of conceptual

  8. Predicting brain activation patterns associated with individual lexical concepts based on five sensory-motor attributes.

    PubMed

    Fernandino, Leonardo; Humphries, Colin J; Seidenberg, Mark S; Gross, William L; Conant, Lisa L; Binder, Jeffrey R

    2015-09-01

    While major advances have been made in uncovering the neural processes underlying perceptual representations, our grasp of how the brain gives rise to conceptual knowledge remains relatively poor. Recent work has provided strong evidence that concepts rely, at least in part, on the same sensory and motor neural systems through which they were acquired, but it is still unclear whether the neural code for concept representation uses information about sensory-motor features to discriminate between concepts. In the present study, we investigate this question by asking whether an encoding model based on five semantic attributes directly related to sensory-motor experience - sound, color, visual motion, shape, and manipulation - can successfully predict patterns of brain activation elicited by individual lexical concepts. We collected ratings on the relevance of these five attributes to the meaning of 820 words, and used these ratings as predictors in a multiple regression model of the fMRI signal associated with the words in a separate group of participants. The five resulting activation maps were then combined by linear summation to predict the distributed activation pattern elicited by a novel set of 80 test words. The encoding model predicted the activation patterns elicited by the test words significantly better than chance. As expected, prediction was successful for concrete but not for abstract concepts. Comparisons between encoding models based on different combinations of attributes indicate that all five attributes contribute to the representation of concrete concepts. Consistent with embodied theories of semantics, these results show, for the first time, that the distributed activation pattern associated with a concept combines information about different sensory-motor attributes according to their respective relevance. Future research should investigate how additional features of phenomenal experience contribute to the neural representation of conceptual

  9. Predicting brain activation patterns associated with individual lexical concepts based on five sensory-motor attributes.

    PubMed

    Fernandino, Leonardo; Humphries, Colin J; Seidenberg, Mark S; Gross, William L; Conant, Lisa L; Binder, Jeffrey R

    2015-09-01

    While major advances have been made in uncovering the neural processes underlying perceptual representations, our grasp of how the brain gives rise to conceptual knowledge remains relatively poor. Recent work has provided strong evidence that concepts rely, at least in part, on the same sensory and motor neural systems through which they were acquired, but it is still unclear whether the neural code for concept representation uses information about sensory-motor features to discriminate between concepts. In the present study, we investigate this question by asking whether an encoding model based on five semantic attributes directly related to sensory-motor experience - sound, color, visual motion, shape, and manipulation - can successfully predict patterns of brain activation elicited by individual lexical concepts. We collected ratings on the relevance of these five attributes to the meaning of 820 words, and used these ratings as predictors in a multiple regression model of the fMRI signal associated with the words in a separate group of participants. The five resulting activation maps were then combined by linear summation to predict the distributed activation pattern elicited by a novel set of 80 test words. The encoding model predicted the activation patterns elicited by the test words significantly better than chance. As expected, prediction was successful for concrete but not for abstract concepts. Comparisons between encoding models based on different combinations of attributes indicate that all five attributes contribute to the representation of concrete concepts. Consistent with embodied theories of semantics, these results show, for the first time, that the distributed activation pattern associated with a concept combines information about different sensory-motor attributes according to their respective relevance. Future research should investigate how additional features of phenomenal experience contribute to the neural representation of conceptual

  10. Digital Coordinates and Age of More Than 13,000 Foraminifers Samples Collected by Chevron Petroleum Geologists in California

    USGS Publications Warehouse

    Malmblorg, William T.; West, William B.; Brabb, Earl E.; Parker, John M.

    2008-01-01

    The general location and age of more than 33,500 mostly foraminifer samples from Chevron surface localities in nearly 600 U.S. Geological Survey (USGS) 7.5' quadrangles from California were provided by Brabb and Parker (2003). Barren and non-diagnostic samples plus many that have no paleontologic information were omitted to provide a revised list for more than 27,000 of these samples by Brabb and Parker (2005). The locations for many of these samples were recorded by Chevron geoscientists on topographic maps (originals now in the USGS Library in Menlo Park, Calif.). The recent availability of digital databases for geologic and topographic maps has provided the opportunity to prepare a database of the locations of these Chevron samples so that the information can be combined with geology and topography for plotting or geospatial analysis. This report provides specific locations for more than 13,000 samples in central California that have enough paleontologic information to determine their age but omits thousands of samples that are too closely spaced to differentiate or those that have only a general location.

  11. Ultrasonically Assisted Anchoring of Biodegradable Implants for Chevron Osteotomies – Clinical Evaluation of a Novel Fixation Method

    PubMed Central

    Olms, Kai; Randt, Thorsten; Reimers, Nils; Zander, Nils; Schulz, Arndt P.

    2014-01-01

    Reconstructive osteotomies for the treatment of Hallux valgus are among the most prevalent procedures in foot and ankle surgery. The combination of biodegradable materials with an innovative method for fixation by application of ultrasonic energy facilitates a new bonding method for fractures or osteotomies. As clinical experience is still limited, the aim of this study was to assess the safety and performance of the SonicPin system for fixation of Austin/Chevron osteotomies. Chevron osteotomy was performed on 30 patients for the treatment of Hallux valgus. The used SonicPins were made from polylactide and are selectively melted into the cancellous bone structure during insertion by ultrasonic energy. Patients were followed for one year, which included X-ray and MRI examinations as well as evaluation of life quality by EQ-5D (EuroQol). The MRI after three months showed adequate bone healing in all cases and no signs of foreign body reactions, which was again confirmed by MRI 12 months postoperatively. The bony healing after 12 months was uneventful without any signs of foreign body reactions. In summary, based on the low complication rate and the significant improvement in health related quality of life (EQ-5D) reported in this study, fixation of an Austin/Chevron osteotomy with a SonicPin for treatment of Hallux valgus can be considered to be safe and efficient over the short term. Level of Clinical Evidence: Therapeutic Level III. PMID:24851140

  12. Self-conception and life satisfaction: integrating aged subculture and activity theory.

    PubMed

    McClelland, K A

    1982-11-01

    This study seeks to expand the traditional activity theory explanation of adjustment to aging by integrating it with the aged subculture theory advanced by Rose. A path model is developed that adds self-conception to social activity, social adequacy, and other predictors of life satisfaction. This model is applied, using an analysis of covariance structures approach, to data from two subsamples of older adults from a national Harris survey. As a result of this analysis, self-conception is shown to be an important intervening variable between social activity and life satisfaction, especially for the subsample of older people who prefer to spend time with others their own age. Finally, a symbolic interactionist perspective is suggested for understanding the importance of self-conception in the process of successful aging.

  13. Elevated-temperature fracture resistances of monolithic and composite ceramics using chevron-notched bend tests

    NASA Technical Reports Server (NTRS)

    Ghosh, Asish; Jenkins, Michael G.; Ferber, Mattison K.; Peussa, Jouko; Salem, Jonathan A.

    1992-01-01

    The quasi-static fracture behaviors of monolithic ceramics (SiC, Si3N4, MgAl2O4), self-reinforced monoliths (acicular grained Si3N4, acicular grained mullite), and ceramic matrix composites (SiC whisker/Al2O3 matrix, TiB2 particulate/SiC matrix, SiC fiber/CVI SiC matrix, Al2O3 fiber/CVI SiC matrix) were measured over the temperature range of 20 to 1400 C. The chevron notched, bend bar test geometry was essential for characterizing the elevated temperature fracture resistances of this wide range of quasi-brittle materials during stable crack growth. Fractography revealed the differences in the fracture behavior of the different materials at the various temperatures. The fracture resistances of the self-reinforced monoliths were comparable to those of the composites and the fracture mechanisms were found to be similar at room temperature. However at elevated temperatures the differences of the fracture behavior became apparent where the superior fracture resistance of the self-reinforced monoliths were attributed to the minor amounts of glassy, intergranular phases which were often more abundant in the composites and affected the fracture behavior when softened by elevated temperatures.

  14. Characterization of a highly efficient chevron-shaped anti-contamination device

    NASA Astrophysics Data System (ADS)

    Fiore, M.; Vermeersch, O.; Forte, M.; Casalis, G.; François, C.

    2016-04-01

    This paper is devoted to the characterization of an optimized chevron-shaped anti-contamination device (ACD). This device can prevent efficiently the propagation of turbulence from the fuselage along the attachment line (hypothetical streamline that spreads the flow going to suction side and the one going to pressure side) of swept wings and enables the development of a new laminar boundary layer downstream. More specifically, the aim is to prevent boundary-layer transition along the attachment line by a contamination process. This process is characterized by the typical Reynolds number overline{R} and the associated Poll's criterion. Thus, ACD efficiency will be expressed in terms of overline{R} values. Some experiments performed on a new numerically optimized ACD have shown its ability to prevent leading-edge contamination up to overline{R} values close to the natural transition process of the laminar boundary layer along the attachment line. The corresponding stability analysis of the laminar boundary layer is made using the Görtler-Hämmerlin stability approach. The study is completed with the different transition processes that can occur downstream the attachment line, around the airfoil, especially with crossflow analysis.

  15. Concept of variable activation energy and its validity in nonisothermal kinetics.

    PubMed

    Tan, Guanglei; Wang, Qi; Zheng, Hongxia; Zhao, Wei; Zhang, Song; Liu, Zhongsuo

    2011-06-01

    The concept of variable activation energy in solid-state kinetics under nonisothermal conditions has been suffering from doubt and controversy. Rate equations of nonisothermal kinetics of solid decomposition, which involve the factors of thermodynamics conditions, pressure of gaseous product, structure parameters of solid, and/or extent of conversion, are derived from the models of the interface reaction, the diffusion of gaseous product, and the nuclei growth of the solid product, respectively. The definition of the validity function in the rate equations represents the influence of the factors on the reaction rate. A function of variable activation energy depending on the validity function is also developed. The changing trend and degree of activation energy are extrapolated from the function of variable activation energy and based on the data of nonisothermal thermal decomposition of calcium carbonate. It is shown that the concept of variable activation energy is meaningfully applicable to solid-state reactions under nonisothermal conditions.

  16. Brief report: Performing on the stage, the field, or both? Australian adolescent extracurricular activity participation and self-concept.

    PubMed

    Blomfield, Corey J; Barber, Bonnie L

    2009-06-01

    The relationship between Australian adolescents' participation in extracurricular activities and their self-concepts was investigated. A total of 1489 adolescents (56% female; mean age 13.8 years) completed measures of social self-concept, academic self-concept, and general self-worth, and reported on their extracurricular activity participation. In general, participation in any type of extracurricular activity was associated with a higher social and academic self-concept, and general self-worth, compared to no participation. Adolescents who participated in both sports and non-sports also reported a more positive social self-concept and general self-worth, compared to those who only participated in one of the activity types. This research provides support for extracurricular activities as a context facilitative of positive self-concept, and demonstrates the importance of a mixed participation profile for an adolescent's self-concept.

  17. Projectile Activity for the Laboratory: A Safe and Inexpensive Approach to Several Concepts

    ERIC Educational Resources Information Center

    Farkas, N.; Ramsier, R. D.

    2006-01-01

    We present a simple laboratory activity for introductory-level physics students which involves rolling balls down pipes and analysing their subsequent flight trajectories. Using balls of equal size but different mass allows students to confront their misconceptions of a mass dependence of the exit speed of the balls from the pipes. The concepts of…

  18. Teaching chemistry concepts using differentiated instruction via tiered labs and activity menus

    NASA Astrophysics Data System (ADS)

    Collins, Betsy C.

    Today's high school classrooms are composed of students with different levels of knowing and ways of understanding. Differentiating the type of work that they are asked to do to achieve the same objective is one way to meet each student's special circumstances on a somewhat equal playing field. By doing so, students are being challenged at their level rather than just blindly going through the same motions that they see others around them doing. Offering students choices to better understand a concept places the student in the driver seat of their educational journey. The purpose of this research project was to design and implement choice activities within the chemistry classroom to more appropriately teach and assess chemistry concepts and assess understanding of those concepts. These choice activities included tiered-laboratory investigations and activity menus. This project was implemented over the course of two trimesters in a high school chemistry classroom. Topics covered included calculating and interpreting density and applying significant figures, calculating and interpreting percent composition with the mole concept, and stoichiometry. The effectiveness of the tiered-labs and activity menus were evaluated using pre and post test comparisons, student surveys, and general in-class observations. Gains in conceptual understanding and student motivation were documented. These findings indicated that allowing choice and leveling of skills to achieve the same conceptual understanding promoted student learning and the overall enjoyment and motivation for learning.

  19. Conceptual and Methodological Considerations in Self-Concept and Participation in School Activities Reanalyzed.

    ERIC Educational Resources Information Center

    Gauthier, William J., Jr.; Yaworth, Joseph S.

    1980-01-01

    Winne and Walsh's Reanalysis (EJ 229 157) of Gauthier and Yarworth's study of self-concept and participation in high school activities (EJ 189 606) is addressed, particularly with respect to the statistical techniques used. The intentions of the original article are also clarified. (GDC)

  20. The Impact of Enrichment Activities upon the Self-Concept of Secondary Cooperative Office Education Students.

    ERIC Educational Resources Information Center

    Davis-Newton, Hazel C.

    A study examined the effect of a series of enrichment activities on the self-concept of 34 cooperative office education students in the East Baton Rouge School Parish (Louisiana). The students participated in an enrichment program consisting of 10 55-minute class periods of instruction in human relations and communication skills, ways of coping…

  1. The Effects of Computer-Aided Concept Cartoons and Outdoor Science Activities on Light Pollution

    ERIC Educational Resources Information Center

    Aydin, Güliz

    2015-01-01

    The purpose of this study is to create an awareness of light pollution on seventh grade students via computer aided concept cartoon applications and outdoor science activities and to help them develop solutions; and to determine student opinions on the practices carried out. The study was carried out at a middle school in Mugla province of Aegean…

  2. a New Concept for AN Active Element for the Large Cosmic Ray Calorimeter ANI

    NASA Astrophysics Data System (ADS)

    Steinbuegl, F.; Gebauer, J.; Lorenz, E.; Mirzoyan, R.; Chilingarian, A.; Ferenc, D.; Jokele, B.

    2002-11-01

    For the half completed ANI sampling calorimeter (1600 m2 detection area, 6 concrete absorber layers of 1 m thickness each) at Mount Aragats, Armenia, a cheap and efficient active detector element is needed. A new concept for such a detector element and first results from a reduced size prototype are presented.

  3. The Effect of Weight on Self-Concept, and Psychosocial Correlates of Physical Activity in Youths

    ERIC Educational Resources Information Center

    Welk, Gregory J.; Joens-Matre, Roxane

    2007-01-01

    Much more attention has been given to the health implications of overweight and obesity than to the psychosocial implications. In order to combat obesity effectively, it is important to understand the implications of overweight on self-concept, self-esteem, and physical activity levels. Youth obesity has been associated with negative psychosocial…

  4. Improving Operations Management Concept Recollection via the Zarco Experiential Learning Activity

    ERIC Educational Resources Information Center

    Polito, Tony; Kros, John; Watson, Kevin

    2004-01-01

    In this study, the authors investigated the effect of Zarco, an operations management "mock factory" experiential learning activity, on student recollection of operations management concepts. Using a number of single-factor and multiple-factor analyses of variance, the authors compared the recollection of students treated with the Zarco activity…

  5. How Does Technology-Enabled Active Learning Affect Undergraduate Students' Understanding of Electromagnetism Concepts?

    ERIC Educational Resources Information Center

    Dori, Yehudit Judy; Belcher, John

    2005-01-01

    Educational technology supports meaningful learning and enables the presentation of spatial and dynamic images, which portray relationships among complex concepts. The Technology-Enabled Active Learning (TEAL) Project at the Massachusetts Institute of Technology (MIT) involves media-rich software for simulation and visualization in freshman…

  6. The Effect of Science Activities on Concept Acquisition of Age 5-6 Children Groups

    ERIC Educational Resources Information Center

    Dogru, Mustafa; Seker, Fatih

    2012-01-01

    Present research aims to determine the effect of science activities on concept development of preschool period age 5-6 children groups. Parallel to research objective, qualitative research pattern has been the selected method. Study group comprises of collectively 48 children from 5-6 age group attending to a private education institution in city…

  7. Using Informal Inferential Reasoning to Develop Formal Concepts: Analyzing an Activity

    ERIC Educational Resources Information Center

    Weinberg, Aaron; Wiesner, Emilie; Pfaff, Thomas J.

    2010-01-01

    Inferential reasoning is a central component of statistics. Researchers have suggested that students should develop an informal understanding of the ideas that underlie inference before learning the concepts formally. This paper presents a hands-on activity that is designed to help students in an introductory statistics course draw informal…

  8. Effect of Instruction Based on Conceptual Change Activities on Students' Understanding of Static Electricity Concepts

    ERIC Educational Resources Information Center

    Baser, Mustafa; Geban, Omer

    2007-01-01

    This study was conducted to investigate the effectiveness of learning activities based on conceptual change conditions and traditionally designed physics instruction on tenth-grade students' understanding of static electricity concepts and their attitudes toward physics as a school subject. Misconceptions related to static electricity concepts…

  9. Study on a novel panel support concept for radio telescopes with active surface

    NASA Astrophysics Data System (ADS)

    Yang, Dehua; Zhou, Guohua; Okoh, Daniel; Li, Guoping; Cheng, Jingquan

    2010-07-01

    Generally, panels of radio telescopes are mainly shaped in trapezoid and each is supported/positioned by four adjustors beneath its vertexes. Such configuration of panel supporting system is essentially hyper-static, and the panel is overconstrained from a kinematic point of view. When the panel is to be adjusted and/or actuated, it will suffer stress from its adjusters and hence its shape is to be distorted. This situation is not desirable for high precision panels, such as glass based panels especially used for sub-millimeter and shorter wavelength telescopes with active optics/active panel technology. This paper began with a general overview of panel patterns and panel supports of existing radio telescopes. Thereby, we proposed a preferable master-slave active surface concept for triangular and/or hexagonal panel pattern. In addition, we carry out panel error sensitivity analysis for all the 6 degrees of freedom (DOF) of a panel to identify what DOFs are most sensitive for an active surface. And afterwards, based on the error sensitivity analysis, we suggested an innovative parallel-series concept hexapod well fitted for an active panel to correct for all of its 6 rigid errors. A demonstration active surface using the master-slave concept and the hexapod manifested a great save in cost, where only 486 precision actuators are needed for 438 panels, which is 37% of those actuators needed by classic segmented mirror active optics. Further, we put forward a swaying-arm based design concept for the related connecting joints between panels, which ensures that all the panels attached on to it free from over-constraints when they are positioned and/or actuated. Principle and performance of the swaying-arm connecting mechanism are elaborated before a practical cablemesh based prototype active surface is presented with comprehensive finite element analysis and simulation.

  10. Interfacial toughness of bilayer dental ceramics based on a short-bar, chevron-notch test

    PubMed Central

    Anunmana, Chuchai; Anusavice, Kenneth J.; Mecholsky, John J.

    2009-01-01

    Objective The objective of this study was to test the null hypothesis that the interfacial toughness of each of two types of bonded core-veneer bilayer ceramics is not significantly different from the apparent fracture toughness of the control monolithic glass veneer. Methods T-shaped short bars of a lithia-disilicate glass-ceramic core (LC) and yttria-stabilized polycrystalline zirconia core ceramic (ZC) were prepared according to the manufacturer's recommendations. V-shaped notches were prepared by using 25-μm-thick palladium foil, leaving the chevron notch area exposed, and the bars were veneered with a thermally compatible glass veneer (LC/GV and ZC/GV). Additionally, we also bonded the glass veneer to itself as a control group (GV/GV). Specimens were kept in distilled water for 30 days before testing in tension. Eight glass veneer bars were prepared for the analysis of fracture toughness test using the indentation-strength technique. Results The mean interfacial toughness of the LC/GV group was 0.69 [0.11] MPa·m1/2, and did not significantly differ from that of the GV/GV control group, 0.74 (0.17) MPa·m1/2 (p > 0.05). However, the difference between the mean interfacial toughness of the ZC/GV group, 0.13 (0.07) MPa·m1/2, and the LC/GV and the GV/GV groups was statistically significant (p<0.05). Significance For bilayer all-ceramic restorations with high-strength core materials, the veneering ceramics are the weakest link in the design of the structure. Since all-ceramic restorations often fail from chipping of veneer layers or crack initiation at the interface, the protective effects of thermal mismatch stresses oral prosthesis design should be investigated. PMID:19818486

  11. Activities for Teaching K-6 Math/Science Concepts. Classroom Activities Series - Number 2.

    ERIC Educational Resources Information Center

    Farmer, Walter A.; Farrell, Margaret A.

    This book is a revised edition of one of the products of a project, "Teaching Mathematics and Science Concepts, K-6, funded by the New York State Education Department. The project was a collaborative effort by mathematics and science education faculty at the State University of New York at Albany and representatives of eight school districts in…

  12. Concepts for the design of a completely active helicopter isolation system using output vector feedback

    NASA Technical Reports Server (NTRS)

    Schulz, G.

    1977-01-01

    The theory of output vector feedback (a few measured quantities) is used to derive completely active oscillation isolation functions for helicopters. These feedback controller concepts are tested with various versions of the BO 105 helicopter and their performance is demonstrated. A compensation of the vibrational excitations from the rotor and harmonics of the number of blades are considered. There is also a fast and automatic trim function for maneuvers.

  13. Physical Self-Concept, Trait Depression and Readiness for Physical Activity of Obese Patients

    ERIC Educational Resources Information Center

    Boros, Szilvia; Halmy, Laszlo

    2009-01-01

    Study aim: To assess the physical self-concept, trait depression and readiness for physical activity in relation to the degree of obesity. Material and methods: Obese (Grade I and II; n = 59) and morbidly obese (Grade III; n = 42) patients aged 30-66 years, as well as 83 non-obese college students aged 30 [plus or minus] 7.3 years were studied.…

  14. The Mediating Role of Physical Self-Concept on Relations between Biological Maturity Status and Physical Activity in Adolescent Females

    ERIC Educational Resources Information Center

    Cumming, Sean P.; Standage, Martyn; Loney, Tom; Gammon, Catherine; Neville, Helen; Sherar, Lauren B.; Malina, Robert M.

    2011-01-01

    The current study examined the mediating role of physical self-concept on relations between biological maturity status and self-reported physical activity in adolescent British females. Biological maturity status, physical self-concept and physical activity were assessed in 407 female British year 7-9 pupils (M age = 13.2 years, SD = 1.0).…

  15. Chevron: Refinery Identifies $4.4 Million in Annual Savings by Using Process Simulation Models to Perform Energy-Efficiency Assessment

    SciTech Connect

    Not Available

    2004-05-01

    In an energy-efficiency study at its refinery near Salt Lake City, Utah, Chevron focused on light hydrocarbons processing. The company found it could recover hydrocarbons from its fuel gas system and sell them. By using process simulation models of special distillation columns and associated reboilers and condensers, Chevron could predict the performance of potential equipment configuration changes and process modifications. More than 25,000 MMBtu in natural gas could be saved annually if a debutanizer upgrade project and a new saturated gas plant project were completed. Together, these projects would save $4.4 million annually.

  16. The Effects of High Adventure Activities on Adolescent Self-Concept: A Comparison of Situationally Specific Self-Concept Measurements and Global Self-Concept Measurements.

    ERIC Educational Resources Information Center

    Wright, Alan N.

    Changes in adolescents' self concept as a result of participation in a camping program were studied. Subjects were 57 males and females, aged 14-18, who spent 9 weeks with the Man and His Land program, travelling on eight camping expeditions. Three hypotheses were tested through pre-, mid-, and posttests: (1) Differences would be shown in pre- and…

  17. Active and passive structural design concepts for improved empennage effectiveness of aircraft

    NASA Astrophysics Data System (ADS)

    Weiss, Franz; Schweiger, Johannes; Simpson, John; Kullrich, Thomas

    2000-06-01

    Active structures concepts for the design of aircraft have been investigated for several years. Concerning static aeroelastic applications, all concepts known to the authors are trying to improve the design of aircraft wings. In the case of wings however, the design space for active structures concepts is limited by a multitude of functional requirements. Empennage surfaces on the other hand only have to meet two basic requirements: sufficient stability and maneuverability for the longitudinal and lateral motion of the aircraft. In the case of vertical tails, the aerodynamic effectiveness for the side force and for the rudder yawing moment are usually reduced by the flexibility of the structure. This causes a weight increase for the structure, which is especially unpleasant for tail surfaces because of the rearward shift of the center of gravity. Today, multidisciplinary structural optimization methods can be used to minimize the weight penalty for static aeroelastic effectiveness requirements. But an amount of penalty still remains. A smart solution for additional weight savings, if possible below the conventional basic strength design of the structure, would therefore be very welcome for any new aircraft design. The paper will describe a new design approach for vertical tails. The concept is based on a smart system for the attachment of the complete tail surface to the fuselage. If properly designed, the variable stiffness of this system will provide improved aerodynamic effectiveness of the tail at any flight condition compared to the rigid aircraft. In a first step, the structure for the vertical tail of a fighter aircraft is designed for static strength and buckling stability by means of a structural optimization program, which is based on finite element methods. The impacts of static aeroelastic effectiveness and flutter stability criteria on the structural design are shown. A modified structural model is then used to incorporate the active system for the

  18. Teaching Plate Tectonic Concepts using GeoMapApp Learning Activities

    NASA Astrophysics Data System (ADS)

    Goodwillie, A. M.; Kluge, S.

    2012-12-01

    GeoMapApp Learning Activities ( http://serc.carleton.edu/geomapapp/collection.html ) can help educators to expose undergraduate students to a range of earth science concepts using high-quality data sets in an easy-to-use map-based interface called GeoMapApp. GeoMapApp Learning Activities require students to interact with and analyse research-quality geoscience data as a means to explore and enhance their understanding of underlying content and concepts. Each activity is freely available through the SERC-Carleton web site and offers step-by-step student instructions and answer sheets. Also provided are annotated educator versions of the worksheets that include teaching tips, additional content and suggestions for further work. The activities can be used "off-the-shelf". Or, since the educator may require flexibility to tailor the activities, the documents are provided in Word format for easy modification. Examples of activities include one on the concept of seafloor spreading that requires students to analyse global seafloor crustal age data to calculate spreading rates in different ocean basins. Another activity has students explore hot spots using radiometric age dating of rocks along the Hawaiian-Emperor seamount chain. A third focusses upon the interactive use of contours and profiles to help students visualise 3-D topography on 2-D computer screens. A fourth activity provides a study of mass wasting as revealed through geomorphological evidence. The step-by-step instructions and guided inquiry approach reduce the need for teacher intervention whilst boosting the time that students can spend on productive exploration and learning. The activities can be used, for example, in a classroom lab with the educator present and as self-paced assignments in an out-of-class setting. GeoMapApp Learning Activities are funded through the NSF GeoEd program and are aimed at students in the introductory undergraduate, community college and high school levels. The activities are

  19. Unintended Embodiment of Concepts into Percepts: Sensory Activation Boosts Attention for Same-Modality Concepts in the Attentional Blink Paradigm

    ERIC Educational Resources Information Center

    Vermeulen, Nicolas; Mermillod, Martial; Godefroid, Jimmy; Corneille, Olivier

    2009-01-01

    This study shows that sensory priming facilitates reports of same-modality concepts in an attentional blink paradigm. Participants had to detect and report two target words (T1 and T2) presented for 53 ms each among a series of nonwords distractors at a frequency of up to 19 items per second. SOA between target words was set to 53 ms or 213 ms,…

  20. Evaluation of a large capacity heat pump concept for active cooling of hypersonic aircraft structure

    NASA Technical Reports Server (NTRS)

    Pagel, L. L.; Herring, R. L.

    1978-01-01

    Results of engineering analyses assessing the conceptual feasibility of a large capacity heat pump for enhancing active cooling of hypersonic aircraft structure are presented. A unique heat pump arrangement which permits cooling the structure of a Mach 6 transport to aluminum temperatures without the aid of thermal shielding is described. The selected concept is compatible with the use of conventional refrigerants, with Freon R-11 selected as the preferred refrigerant. Condenser temperatures were limited to levels compatible with the use of conventional refrigerants by incorporating a unique multipass condenser design, which extracts mechanical energy from the hydrogen fuel, prior to each subsequent pass through the condenser. Results show that it is technically feasible to use a large capacity heat pump in lieu of external shielding. Additional analyses are required to optimally apply this concept.

  1. Event-related potentials reveal early activation of body part representations in action concept comprehension.

    PubMed

    Lu, Aitao; Liu, Jing; Zhang, John X

    2012-03-01

    With tasks involving action concept comprehension, many fMRI studies have reported brain activations in sensori-motor regions specific to effectors of the referent action. There is relatively less evidence whether such activations reflect early semantic access or late conceptual re-processing. Here we recorded event-related potentials when participants recognized noun-verb pairs. For Congruent pairs, the verb was the one most commonly associated with the noun (e.g., football-kick). Compared with a control condition, verbs in Congruent pairs showed priming effects in the time windows of 100-150 ms and 210-260 ms. Such activation seems to be specific to body part but not other aspects of the action as similar priming effect was also found when the noun and verb involved different actions though sharing the same body part (e.g., football-jump), documenting for the first time the early activation of body part representations in action concept comprehension. PMID:22306088

  2. Event-related potentials reveal early activation of body part representations in action concept comprehension.

    PubMed

    Lu, Aitao; Liu, Jing; Zhang, John X

    2012-03-01

    With tasks involving action concept comprehension, many fMRI studies have reported brain activations in sensori-motor regions specific to effectors of the referent action. There is relatively less evidence whether such activations reflect early semantic access or late conceptual re-processing. Here we recorded event-related potentials when participants recognized noun-verb pairs. For Congruent pairs, the verb was the one most commonly associated with the noun (e.g., football-kick). Compared with a control condition, verbs in Congruent pairs showed priming effects in the time windows of 100-150 ms and 210-260 ms. Such activation seems to be specific to body part but not other aspects of the action as similar priming effect was also found when the noun and verb involved different actions though sharing the same body part (e.g., football-jump), documenting for the first time the early activation of body part representations in action concept comprehension.

  3. New insights into the multidimensional concept of macrophage ontogeny, activation and function.

    PubMed

    Ginhoux, Florent; Schultze, Joachim L; Murray, Peter J; Ochando, Jordi; Biswas, Subhra K

    2016-01-01

    Macrophages have protective roles in immunity to pathogens, tissue development, homeostasis and repair following damage. Maladaptive immunity and inflammation provoke changes in macrophage function that are causative of disease. Despite a historical wealth of knowledge about macrophages, recent advances have revealed unknown aspects of their development and function. Following development, macrophages are activated by diverse signals. Such tissue microenvironmental signals together with epigenetic changes influence macrophage development, activation and functional diversity, with consequences in disease and homeostasis. We discuss here how recent discoveries in these areas have led to a multidimensional concept of macrophage ontogeny, activation and function. In connection with this, we also discuss how technical advances facilitate a new roadmap for the isolation and analysis of macrophages at high resolution.

  4. High-density active optical cable: from a new concept to a prototype

    NASA Astrophysics Data System (ADS)

    Wohlfeld, Denis; Lemke, Frank; Froening, Holger; Schenk, Sven; Bruening, Ulrich

    2011-01-01

    Evolution in high performance computing (HPC) leads to increasing demands on bandwidth, connectivity and flexibility. Active optical cables (AOC) are of special interest, combining the benefits of electrical connectors and optical transmission. Optimization and development of AOC solutions requires enhancements concerning different technology barriers. Area and volume occupied by connectors is of special interest within HPC networks. This led to the development of a 12x AOC for the mini-HT connector creating the densest AOC available. In order to integrate electrical optical conversion into a module not higher than 3 mm, a new concept of coupling fibers to VCSELs or photodiodes had to be developed. This unique concept is based on a direct replication process of an integrated fiber coupler consisting of a 90° light deflecting and focusing mirror, a fiber guiding structure, and a fiber funnel. The integrated fiber coupler is directly replicated on top of active components, reducing the distance between active components and fibers to a minimum, thus providing a highly efficient light coupling. As AOC prototype, multi-chipmodules (MCM) including the complete electrical to optical conversion for send and receive connected by two 12x fiber ribbons have been developed. The paper presents the integrated fiber coupling technique and also design and measurement data of the prototype.

  5. Nanocrystals of medium soluble actives--novel concept for improved dermal delivery and production strategy.

    PubMed

    Zhai, Xuezhen; Lademann, Jürgen; Keck, Cornelia M; Müller, Rainer H

    2014-08-15

    After use in oral pharmaceutical products, nanocrystals are meanwhile applied to improve the dermal penetration of cosmetic actives (e.g. rutin, hesperidin) and of drugs. By now, nanocrystals are only dermally applied made from poorly soluble actives. The novel concept is to formulate nanocrystals also from medium soluble actives, and to apply a dermal formulation containing additionally nanocrystals. The nanocrystals should act as fast dissolving depot, increase saturation solubility and especially accumulate in the hair follicles, to further increase skin penetration. Caffeine was used as model compound with relevance to market products, and a particular process was developed for the production of caffeine nanocrystals to overcome the supersaturation related effect of crystal growth and fiber formation - typical with medium soluble compounds. It is based on low energy milling (pearl milling) in combination with low dielectric constant dispersion media (water-ethanol or ethanol-propylene glycol mixtures) and optimal stabilizers. Most successful was Carbopol(®) 981 (e.g. 20% caffeine in ethanol-propylene glycol 3:7 with 2% Carbopol, w/w). Nanocrystals with varied sizes can now be produced in a controlled process e.g. 660 nm (optimal for hair follicle accumulation) to 250 nm (optimal for fast dissolution). The short term test proved stability over 2 months of the present formulation being sufficient to perform in vivo testing of the novel concept.

  6. From Concept-to-Flight: An Active Active Fluid Loop Based Thermal Control System for Mars Science Laboratory Rover

    NASA Technical Reports Server (NTRS)

    Birur, Gajanana C.; Bhandari, Pradeep; Bame, David; Karlmann, Paul; Mastropietro, A. J.; Liu, Yuanming; Miller, Jennifer; Pauken, Michael; Lyra, Jacqueline

    2012-01-01

    The Mars Science Laboratory (MSL) rover, Curiosity, which was launched on November 26, 2011, incorporates a novel active thermal control system to keep the sensitive electronics and science instruments at safe operating and survival temperatures. While the diurnal temperature variations on the Mars surface range from -120 C to +30 C, the sensitive equipment are kept within -40 C to +50 C. The active thermal control system is based on a single-phase mechanically pumped fluid loop (MPFL) system which removes or recovers excess waste heat and manages it to maintain the sensitive equipment inside the rover at safe temperatures. This paper will describe the entire process of developing this active thermal control system for the MSL rover from concept to flight implementation. The development of the rover thermal control system during its architecture, design, fabrication, integration, testing, and launch is described.

  7. Applying Active Learning to Assertion Classification of Concepts in Clinical Text

    PubMed Central

    Chen, Yukun; Mani, Subramani; Xu, Hua

    2012-01-01

    Supervised machine learning methods for clinical natural language processing (NLP) research require a large number of annotated samples, which are very expensive to build because of the involvement of physicians. Active learning, an approach that actively samples from a large pool, provides an alternative solution. Its major goal in classification is to reduce the annotation effort while maintaining the quality of the predictive model. However, few studies have investigated its uses in clinical NLP. This paper reports an application of active learning to a clinical text classification task: to determine the assertion status of clinical concepts. The annotated corpus for the assertion classification task in the 2010 i2b2/VA Clinical NLP Challenge was used in this study. We implemented several existing and newly developed active learning algorithms and assessed their uses. The outcome is reported in the global ALC score, based on the Area under the average Learning Curve of the AUC (Area Under the Curve) score. Results showed that when the same number of annotated samples was used, active learning strategies could generate better classification models (best ALC – 0.7715) than the passive learning method (random sampling) (ALC – 0.7411). Moreover, to achieve the same classification performance, active learning strategies required fewer samples than the random sampling method. For example, to achieve an AUC of 0.79, the random sampling method used 32 samples, while our best active learning algorithm required only 12 samples, a reduction of 62.5% in manual annotation effort. PMID:22127105

  8. An Overview of Propulsion Concept Studies and Risk Reduction Activities for Robotic Lunar Landers

    NASA Technical Reports Server (NTRS)

    Trinh, Huu P.; Story, George; Burnside, Chris; Kudlach, Al

    2010-01-01

    In support of designing robotic lunar lander concepts, the propulsion team at NASA Marshall Space Flight Center (MSFC) and the Johns Hopkins University Applied Physics Laboratory (APL), with participation from industry, conducted a series of trade studies on propulsion concepts with an emphasis on light-weight, advanced technology components. The results suggest a high-pressure propulsion system may offer some benefits in weight savings and system packaging. As part of the propulsion system, a solid rocket motor was selected to provide a large impulse to reduce the spacecraft s velocity prior to the lunar descent. In parallel to this study effort, the team also began technology risk reduction testing on a high thrust-to-weight descent thruster and a high-pressure regulator. A series of hot-fire tests was completed on the descent thruster in vacuum conditions at NASA White Sands Test Facility (WSTF) in New Mexico in 2009. Preparations for a hot-fire test series on the attitude control thruster at WSTF and for pressure regulator testing are now underway. This paper will provide an overview of the concept trade study results along with insight into the risk mitigation activities conducted to date.

  9. Written justifications to multiple-choice concept questions during active learning in class

    NASA Astrophysics Data System (ADS)

    Koretsky, Milo D.; Brooks, Bill J.; Higgins, Adam Z.

    2016-07-01

    Increasingly, instructors of large, introductory STEM courses are having students actively engage during class by answering multiple-choice concept questions individually and in groups. This study investigates the use of a technology-based tool that allows students to answer such questions during class. The tool also allows the instructor to prompt students to provide written responses to justify the selection of the multiple-choice answer that they have chosen. We hypothesize that prompting students to explain and elaborate on their answer choices leads to greater focus and use of normative scientific reasoning processes, and will allow them to answer questions correctly more often. The study contains two parts. First, a crossover quasi-experimental design is employed to determine the influence of asking students to individually provide written explanations (treatment condition) of their answer choices to 39 concept questions as compared to students who do not. Second, we analyze a subset of the questions to see whether students identify the salient concepts and use appropriate reasoning in their explanations. Results show that soliciting written explanations can have a significant influence on answer choice and, when it does, that influence is usually positive. However, students are not always able to articulate the correct reason for their answer.

  10. Statement--fundamental concepts of occupational therapy: occupation, purposeful activity, and function.

    PubMed

    Hinojosa, J; Kramer, P

    1997-01-01

    Deriving from the philosophical basis of the profession, occupation is the core concept of the profession of occupational therapy. However, in the occupational therapy literature, the term occupation is used in a variety of ways. Occupation, a collection of activities that people use to fill their time and give life meaning, is organized around roles or in terms of activities of daily living, work and productive activities, or pleasure, for survival, for necessity, and for their personal meaning. It is the individualized, unique combination of activities that comprises an individual's occupations. Purposeful activities have been described in many different ways: as something all people engage in; as tools or media that therapists use to enhance or facilitate performance; and vehicles for bringing about change. Purposeful activities are seen as part of the process of occupational therapy. Purposeful activities are subset of occupations in that they are goal directed and serve as a major tool in the process of occupational therapy. The term function, viewed as the ability to perform activities required in one's occupations has become increasingly important to society in describing the performance or change in individuals. This societal shift in ideas has prompted the concept of function, viewed as a product, to become more important than the process of bringing about change. Occupational therapy practitioners typically have viewed the process as being just as important as the product. When working to improve function, occupational therapy practitioners use purposeful activities that are meaningful to the person in relation to his or her occupational history, preferences, personal goals, and needs. Occupational therapy practitioners need to keep the individual's occupations in the forefront of their thoughts when using any purposeful activity and to plan interventions toward improving the individual's ability to function within his or her occupations. In the interest

  11. When Are Powerful Learning Environments Effective? The Role of Learner Activities and of Students' Conceptions of Educational Technology

    ERIC Educational Resources Information Center

    Gerjets, Peter H.; Hesse, Friedrich W.

    2004-01-01

    The goal of this chapter is to outline a theoretical and empirical perspective on how learners' conceptions of educational technology might influence their learning activities and thereby determine the power of computer-based learning environments. Starting with an introduction to the concept of powerful learning environments we outline how recent…

  12. Double Stimulation in Strategic Concept Formation: An Activity-Theoretical Analysis of Business Planning in a Small Technology Firm

    ERIC Educational Resources Information Center

    Virkkunen, Jaakko; Ristimaki, Paivi

    2012-01-01

    In this article, we study the relationships between culturally existing general strategy concepts and a small information and communication technology firm's specific strategic challenge in its management team's search for a new strategy concept. We apply three theoretical ideas of cultural historical activity theory: (a) the idea of double…

  13. Instructional Activities to Develop Student Concept Learning and Problem-Solving Skills in Art Education: A Proposed Model.

    ERIC Educational Resources Information Center

    Stahl, Robert J.; Webster, Nancy Comstock

    The purposes of the paper are to discuss use of a concept formation model in art education and to suggest ways in which teachers might plan and develop art instructional activities consistent with the model. Based upon a social studies model designed along the lines of Robert Gagne's learning theory, the art education model utilizes rule, concept,…

  14. Application of the active camber morphing concept based on compliant structures to a regional aircraft

    NASA Astrophysics Data System (ADS)

    De Gaspari, Alessandro; Ricci, Sergio

    2014-04-01

    The present work addresses the optimal design of a morphing mechanism based on compliant structures used to implement the active camber morphing concept. The subject of the work is part of the FP7-NOVEMOR project (Novel Air Vehicle Configurations: From Fluttering Wings to Morphing Flight) which is one of the many projects from the seventh European Framework Programme. The implementation of active camber concept is based on the use of conformable morphing control surfaces. Aiming at the optimal design of such as morphing devices, two dedicated tools called PHORMA and SPHERA, respectively, are introduced. The definition of the optimal shape taking into account both aerodynamic and structural constraints is done by PHORMA. Then SPHERA, based on the load path approach codified by coupling a non linear beam solver to a genetic multi- objective optimizer, is adopted to generate the optimal internal structure able to produce, when loaded, the target optimal shape. The paper is mainly focused on the optimal design of the compliant structures starting from the optimal shape already available for a Reference Aircraft (RA) developed inside NOVEMOR project and representative of a typical regional jet capable to carry 113 PAX in a single economic class.

  15. Selected advanced aerodynamics and active controls technology concepts development on a derivative B-747

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The feasibility of applying wing tip extensions, winglets, and active control wing load alleviation to the Boeing 747 is investigated. Winglet aerodynamic design methods and high speed wind tunnel test results of winglets and of symmetrically deflected ailerons are presented. Structural resizing analyses to determine weight and aeroelastic twist increments for all the concepts and flutter model test results for the wing with winglets are included. Control law development, system mechanization/reliability studies, and aileron balance tab trade studies for active wing load alleviation systems are discussed. Results are presented in the form of incremental effects on L/D, structural weight, block fuel savings, stability and control, airplane price, and airline operating economics.

  16. Using a Concept Mapping Tool with a Photograph Association Technique (CoMPAT) to Elicit Children's Ideas about Microbial Activity

    NASA Astrophysics Data System (ADS)

    Byrne, Jenny; Grace, Marcus

    2010-03-01

    Concept mapping is a technique used to provide a visual representation of an individual's ideas about a concept or set of related concepts. This paper describes a concept mapping tool using a photograph association technique (CoMPAT) that is considered to be a novel way of eliciting children's ideas. What children at 11 years of age know about particular concepts related to microbial activity is presented and discussed in relation to the effectiveness of CoMPAT as a tool to draw out their ideas. It is proposed that this tool could be used to explore ideas about this and other science concepts from children in other age groups, and where language may be a barrier to participation.

  17. A mathematical model of immune activation with a unified self-nonself concept.

    PubMed

    Khailaie, Sahamoddin; Bahrami, Fariba; Janahmadi, Mahyar; Milanez-Almeida, Pedro; Huehn, Jochen; Meyer-Hermann, Michael

    2013-01-01

    The adaptive immune system reacts against pathogenic nonself, whereas it normally remains tolerant to self. The initiation of an immune response requires a critical antigen(Ag)-stimulation and a critical number of Ag-specific T cells. Autoreactive T cells are not completely deleted by thymic selection and partially present in the periphery of healthy individuals that respond in certain physiological conditions. A number of experimental and theoretical models are based on the concept that structural differences discriminate self from nonself. In this article, we establish a mathematical model for immune activation in which self and nonself are not distinguished. The model considers the dynamic interplay of conventional T cells, regulatory T cells (Tregs), and IL-2 molecules and shows that the renewal rate ratio of resting Tregs to naïve T cells as well as the proliferation rate of activated T cells determine the probability of immune stimulation. The actual initiation of an immune response, however, relies on the absolute renewal rate of naïve T cells. This result suggests that thymic selection reduces the probability of autoimmunity by increasing the Ag-stimulation threshold of self reaction which is established by selection of a low number of low-avidity autoreactive T cells balanced with a proper number of Tregs. The stability analysis of the ordinary differential equation model reveals three different possible immune reactions depending on critical levels of Ag-stimulation: a subcritical stimulation, a threshold stimulation inducing a proper immune response, and an overcritical stimulation leading to chronic co-existence of Ag and immune activity. The model exhibits oscillatory solutions in the case of persistent but moderate Ag-stimulation, while the system returns to the homeostatic state upon Ag clearance. In this unifying concept, self and nonself appear as a result of shifted Ag-stimulation thresholds which delineate these three regimes of immune

  18. Modern Radiotherapy Concepts and the Impact of Radiation on Immune Activation

    PubMed Central

    Deloch, Lisa; Derer, Anja; Hartmann, Josefin; Frey, Benjamin; Fietkau, Rainer; Gaipl, Udo S.

    2016-01-01

    Even though there is extensive research carried out in radiation oncology, most of the clinical studies focus on the effects of radiation on the local tumor tissue and deal with normal tissue side effects. The influence of dose fractionation and timing particularly with regard to immune activation is not satisfactorily investigated so far. This review, therefore, summarizes current knowledge on concepts of modern radiotherapy (RT) and evaluates the potential of RT for immune activation. Focus is set on radiation-induced forms of tumor cell death and consecutively the immunogenicity of the tumor cells. The so-called non-targeted, abscopal effects can contribute to anti-tumor responses in a specific and systemic manner and possess the ability to target relapsing tumor cells as well as metastases. The impact of distinct RT concepts on immune activation is outlined and pre-clinical evidence and clinical observations on RT-induced immunity will be discussed. Knowledge on the radiosensitivity of immune cells as well as clinical evidence for enhanced immunity after RT will be considered. While stereotactic ablative body radiotherapy seem to have a beneficial outcome over classical RT fractionation in pre-clinical animal models, in vitro model systems suggest an advantage for classical fractionated RT for immune activation. Furthermore, the optimal approach may differ based on the tumor site and/or genetic signature. These facts highlight that clinical trials are urgently needed to identify whether high-dose RT is superior to induce anti-tumor immune responses compared to classical fractionated RT and in particular how the outcome is when RT is combined with immunotherapy in selected tumor entities. PMID:27379203

  19. Modern Radiotherapy Concepts and the Impact of Radiation on Immune Activation.

    PubMed

    Deloch, Lisa; Derer, Anja; Hartmann, Josefin; Frey, Benjamin; Fietkau, Rainer; Gaipl, Udo S

    2016-01-01

    Even though there is extensive research carried out in radiation oncology, most of the clinical studies focus on the effects of radiation on the local tumor tissue and deal with normal tissue side effects. The influence of dose fractionation and timing particularly with regard to immune activation is not satisfactorily investigated so far. This review, therefore, summarizes current knowledge on concepts of modern radiotherapy (RT) and evaluates the potential of RT for immune activation. Focus is set on radiation-induced forms of tumor cell death and consecutively the immunogenicity of the tumor cells. The so-called non-targeted, abscopal effects can contribute to anti-tumor responses in a specific and systemic manner and possess the ability to target relapsing tumor cells as well as metastases. The impact of distinct RT concepts on immune activation is outlined and pre-clinical evidence and clinical observations on RT-induced immunity will be discussed. Knowledge on the radiosensitivity of immune cells as well as clinical evidence for enhanced immunity after RT will be considered. While stereotactic ablative body radiotherapy seem to have a beneficial outcome over classical RT fractionation in pre-clinical animal models, in vitro model systems suggest an advantage for classical fractionated RT for immune activation. Furthermore, the optimal approach may differ based on the tumor site and/or genetic signature. These facts highlight that clinical trials are urgently needed to identify whether high-dose RT is superior to induce anti-tumor immune responses compared to classical fractionated RT and in particular how the outcome is when RT is combined with immunotherapy in selected tumor entities. PMID:27379203

  20. Disease-modifying therapeutic concepts for HIV in the era of highly active antiretroviral therapy.

    PubMed

    Butler, Scott L; Valdez, Hernan; Westby, Michael; Perros, Manos; June, Carl H; Jacobson, Jeffrey M; Levy, Yves; Cooper, David A; Douek, Daniel; Lederman, Michael M; Tebas, Pablo

    2011-11-01

    Chronic HIV infection is associated with persistent immune activation and inflammation even among patients virologically suppressed on antiretroviral therapy for years. Chronic immune activation has been associated with poor outcomes--both AIDS-defining and non-AIDS-defining clinical events--and persistent CD4 T-cell depletion. The cause of chronic immune activation in well-controlled HIV infection is unknown. Proposed drivers include residual viral replication, microbial translocation, and coinfecting pathogens. Therapeutic interventions targeting immune activation are emerging, from approaches that interfere directly with activation and inflammatory pathways to those that prevent microbial translocation or decrease the availability of host target cells for the virus. In the context of the disappointing results of the interleukin-2 trials, the main challenges to developing these disease-modifying therapies include identifying an adequate target population and choosing surrogate endpoints that will provide positive proof-of-concept that the interventions will translate into long-term clinical benefit before embarking on large clinical endpoint trials. PMID:21792065

  1. The concept of electron activity and its relation to redox potentials in aqueous geochemical systems

    USGS Publications Warehouse

    Thorstenson, D.C.

    1984-01-01

    The definition of a formal thermodynamic activity of electrons in redox reactions appears in the literature of the 1920's. The concept of pe as -log (electron activity) was introduced by Jorgensen in 1945 and popularized in the geochemical literature by Sillen, who considered pe and pH as master variables in geochemical reactions. The physical significance of the concept of electron activity was challenged as early as 1928. However, only in the last two decades have sufficient thermodynamic data become available to examine this question quantitatively. The chemical nature of hydrated electrons differs greatly from that of hydrated protons, and thermodynamic data show that hydrated electrons cannot exist at physically meaningful equilibrium concentrations under natural conditions. This has important consequences for the understanding of redox processes in natural waters. These are: (1) the analogy between pe and pH as master variables is generally carried much further than is justified; (2) a thermodynamically meaningful value of redox potential cannot be assigned to disequilibrium systems; (3) the most useful approach to the study of redox characteristics is the analysis and study of multiple redox couples in the system; and (4) for all practical purposes, thermodynamically defined redox potentials do not exist (and thus cannot be measured) in natural waters. The overall implication for natural systems is that, in terms of redox reactions, each case must be considered on an individual and detailed basis. Field studies would appear to be a mandatory part of any site-specific study; conclusions regarding redox processes cannot be based solely on electrode measurements or thermodynamic stability calculations. (USGS)

  2. The ICESat-2 Mission: Concept, Pre-Launch Activities, and Opportunities

    NASA Technical Reports Server (NTRS)

    Markus, Thorsten; Neumann, Tom; Csatho, Beata M.

    2011-01-01

    Ice sheet and sea level changes have been explicitly identified as a priority in the President's Climate Change Science Program, the Arctic Climate Impact Assessment, the 4th Assessment Report of the IPee and other national and international policy documents. Following recommendations from the National Research Council for an ICESat follow-on mission, the ICESat-2 mission is now under development for launch in early 2016. The primary aims of the ICESat-2 mission are to continue measurements of sea-ice thickness change, and ice sheet elevation changes at scales from outlet glaciers to the entire ice sheet as established by ICES at. In contrast to ICES at, ICESat-2 will employ a 6-beam micro-pulse laser photon-counting approach. The current concept uses a high repetition rate (10 kHz; equivalent to 70 cm on the ground) low-power laser in conjunction with single-photon sensitive detectors to measure range using approximately 532nm (green) light. The concept will enable the generation of seasonal maps of ice sheet elevation of Greenland and Antarctica, monthly maps of sea ice thickness of the polar ocean, a dense map of land elevation (2 km track spacing at the equator after two years) enabling the determination of canopy height, as well as ocean heights. While the mission has been optimized for cryospheric science and vast amount of high precision elevation measurements taken over land and over the ocean as well as of the atmosphere will provide scientists with a wealth of opportunities to explore the utility of ICESat-2. Those will range from the retrieval of cloud properties, to river stages, to snow cover, to land use changes and more. The presentation will review the measurement concept and physical principles of ICESat-2, current and planned activities to assess instrument performance and develop geophysical algorithms, as well as potential opportunities outside the main objectives of ICESat-2.

  3. Activity-Based Restorative Therapies after Spinal Cord Injury: Inter-institutional conceptions and perceptions

    PubMed Central

    Dolbow, David R.; Gorgey, Ashraf S.; Recio, Albert C.; Stiens, Steven A.; Curry, Amanda C.; Sadowsky, Cristina L.; Gater, David R.; Martin, Rebecca; McDonald, John W.

    2015-01-01

    This manuscript is a review of the theoretical and clinical concepts provided during an inter-institutional training program on Activity-Based Restorative Therapies (ABRT) and the perceptions of those in attendance. ABRT is a relatively recent high volume and intensity approach toward the restoration of neurological deficits and decreasing the risk of secondary conditions associated with paralysis after spinal cord injury (SCI). ABRT is guided by the principle of neuroplasticity and the belief that even those with chronic SCI can benefit from repeated activation of the spinal cord pathways located both above and below the level of injury. ABRT can be defined as repetitive-task specific training using weight-bearing and external facilitation of neuromuscular activation. The five key components of ABRT are weight-bearing activities, functional electrical stimulation, task-specific practice, massed practice and locomotor training which includes body weight supported treadmill walking and water treadmill training. The various components of ABRT have been shown to improve functional mobility, and reverse negative body composition changes after SCI leading to the reduction of cardiovascular and other metabolic disease risk factors. The consensus of those who received the ABRT training was that ABRT has much potential for enhancement of recovery of those with SCI. Although various institutions have their own strengths and challenges, each institution was able to initiate a modified ABRT program. PMID:26236547

  4. Activity-Based Restorative Therapies after Spinal Cord Injury: Inter-institutional conceptions and perceptions.

    PubMed

    Dolbow, David R; Gorgey, Ashraf S; Recio, Albert C; Stiens, Steven A; Curry, Amanda C; Sadowsky, Cristina L; Gater, David R; Martin, Rebecca; McDonald, John W

    2015-08-01

    This manuscript is a review of the theoretical and clinical concepts provided during an inter-institutional training program on Activity-Based Restorative Therapies (ABRT) and the perceptions of those in attendance. ABRT is a relatively recent high volume and intensity approach toward the restoration of neurological deficits and decreasing the risk of secondary conditions associated with paralysis after spinal cord injury (SCI). ABRT is guided by the principle of neuroplasticity and the belief that even those with chronic SCI can benefit from repeated activation of the spinal cord pathways located both above and below the level of injury. ABRT can be defined as repetitive-task specific training using weight-bearing and external facilitation of neuromuscular activation. The five key components of ABRT are weight-bearing activities, functional electrical stimulation, task-specific practice, massed practice and locomotor training which includes body weight supported treadmill walking and water treadmill training. The various components of ABRT have been shown to improve functional mobility, and reverse negative body composition changes after SCI leading to the reduction of cardiovascular and other metabolic disease risk factors. The consensus of those who received the ABRT training was that ABRT has much potential for enhancement of recovery of those with SCI. Although various institutions have their own strengths and challenges, each institution was able to initiate a modified ABRT program. PMID:26236547

  5. Attitudes to concept maps as a teaching/learning activity in undergraduate health professional education: influence of preferred learning style.

    PubMed

    Laight, David W

    2004-05-01

    Concept maps that integrate and relate concepts in a nonlinear fashion are widely accepted as an educational tool that can underpin meaningful learning in medical education. However, student take-up may be affected by a number of cognitive and non-cognitive influences. In the present study, student attitudes to pre-prepared concept maps introduced in Stage 2 conjoint MPharm and BSc Pharmacology lectures were examined in relation to preferred learning styles according to the Felder-Silverman model. There was no statistically significant influence of dichotomous learning style dimension (sensing/intuitive; visual/verbal; active/reflector; sequential/global) on the self-reported utility of such concept maps to learning. However, when strength of preference was analysed within each dimension, moderate/strong verbal learners were found to be significantly less likely to self-report concept maps as useful relative to mild verbal learners. With this important exception, these data now suggest that student attitudes to concept maps are broadly not influenced by preferred learning styles and furthermore highlight the potential of concept maps to address a variety of different learning styles and thereby facilitate 'teaching to all types'. Concept maps could therefore potentially assist motivation, engagement and deep learning in medical and biomedical science education when used as a supplement to more traditional teaching/learning activities.

  6. H-II Transfer Vehicle (HTV) and the Operations Concept for Extravehicular Activity (EVA) Hardware

    NASA Technical Reports Server (NTRS)

    Chullen, Cinda

    2010-01-01

    With the retirement of the Space Shuttle fleet imminent in 2011, a new concept of operations will become reality to meet the transportation challenges of the International Space Station (ISS). The planning associated with the retirement of the Space Shuttle has been underway since the announcement in 2004. Since then, several companies and government entities have had to look for innovative low-cost commercial orbital transportation systems to continue to achieve the objectives of ISS delivery requirements. Several options have been assessed and appear ready to meet the large and demanding delivery requirements of the ISS. Options that have been identified that can facilitate the challenge include the Russian Federal Space Agency's Soyuz and Progress spacecraft, European Space Agency's Automated Transfer Vehicle (ATV), the Japan Aerospace Exploration Agency's (JAXA's) H-II Transfer Vehicle (HTV) and the Boeing Delta IV Heavy (DIV-H). The newest of these options is the JAXA's HTV. This paper focuses on the HTV, mission architecture and operations concept for Extra-Vehicular Activities (EVA) hardware, the associated launch system, and details of the launch operations approach.

  7. H-II Transfer Vehicle (HTV) and the Operations Concept for Extravehicular Activity (EVA) Hardware

    NASA Technical Reports Server (NTRS)

    Chullen, Cinda; Blome, Elizabeth; Tetsuya, Sakashita

    2011-01-01

    With the retirement of the Space Shuttle fleet imminent in 2011, a new operations concept will become reality to meet the transportation challenges of the International Space Station (ISS). The planning associated with the retirement of the Space Shuttle has been underway since the announcement in 2004. Since then, several companies and government entities have had to look for innovative low-cost commercial orbital transportation systems to continue to achieve the objectives of ISS delivery requirements. Several options have been assessed and appear ready to meet the large and demanding delivery requirements of the ISS. Options that have been identified that can facilitate the challenge include the Russian Federal Space Agency's Soyuz and Progress spacecraft, European Space Agency's Automated Transfer Vehicle (ATV), and the Japan Aerospace Exploration Agency's (JAXA s) H-II Transfer Vehicle (HTV). The newest of these options is the JAXA's HTV. This paper focuses on the HTV, mission architecture and operations concept for Extra-Vehicular Activities (EVA) hardware, the associated launch system, and details of the launch operations approach.

  8. Unobtrusive behavioral and activity-related multimodal biometrics: The ACTIBIO Authentication concept.

    PubMed

    Drosou, A; Ioannidis, D; Moustakas, K; Tzovaras, D

    2011-03-01

    Unobtrusive Authentication Using ACTIvity-Related and Soft BIOmetrics (ACTIBIO) is an EU Specific Targeted Research Project (STREP) where new types of biometrics are combined with state-of-the-art unobtrusive technologies in order to enhance security in a wide spectrum of applications. The project aims to develop a modular, robust, multimodal biometrics security authentication and monitoring system, which uses a biodynamic physiological profile, unique for each individual, and advancements of the state of the art in unobtrusive behavioral and other biometrics, such as face, gait recognition, and seat-based anthropometrics. Several shortcomings of existing biometric recognition systems are addressed within this project, which have helped in improving existing sensors, in developing new algorithms, and in designing applications, towards creating new, unobtrusive, biometric authentication procedures in security-sensitive, Ambient Intelligence environments. This paper presents the concept of the ACTIBIO project and describes its unobtrusive authentication demonstrator in a real scenario by focusing on the vision-based biometric recognition modalities.

  9. NASA Propulsion Concept Studies and Risk Reduction Activities for Resource Prospector Lander

    NASA Technical Reports Server (NTRS)

    Trinh, Huu P.; Williams, Hunter; Burnside, Chris

    2015-01-01

    The Resource Prospector mission is to investigate the Moon's polar regions in search of volatiles. The government-version lander concept for the mission is composed of a braking stage and a liquid-propulsion lander stage. A propulsion trade study concluded with a solid rocket motor for the braking stage while using the 4th-stage Peacekeeper (PK) propulsion components for the lander stage. The mechanical design of the liquid propulsion system was conducted in concert with the lander structure design. A propulsion cold-flow test article was fabricated and integrated into a lander development structure, and a series of cold flow tests were conducted to characterize the fluid transient behavior and to collect data for validating analytical models. In parallel, RS-34 PK thrusters to be used on the lander stage were hot-fire tested in vacuum conditions as part of risk reduction activities.

  10. A Chang'e-4 mission concept and vision of future Chinese lunar exploration activities

    NASA Astrophysics Data System (ADS)

    Wang, Qiong; Liu, Jizhong

    2016-10-01

    A novel concept for Chinese Chang'e-4 lunar exploration mission is presented in this paper at first. After the success of Chang'e-3, its backup probe, Chang'e-4 lander/rover combination, would be upgraded and land on the unexplored lunar farside by the aid of a relay satellite near the second Earth-Moon Lagrange point. Mineralogical and geochemical surveys on the farside to study the formation and evolution of lunar crust and observations at low radio frequencies to track the signals of the Universe's Dark Ages are priorities. Follow-up Chinese lunar exploration activities before 2030 are envisioned as building a robotic lunar science station by three to five missions. Finally several methods of international cooperation are proposed.

  11. Changing Concepts in Activity: Descriptive and Design Studies of Consequential Learning in Conceptual Practices

    ERIC Educational Resources Information Center

    Hall, Rogers; Jurow, A. Susan

    2015-01-01

    Concepts and conceptual change have been studied extensively as phenomena of individual thinking and action, but changing circumstances of social or cultural groups using concepts are treated as external conditions. We describe research on consequential learning in conceptual practices, where concepts include representational infrastructure that…

  12. Flutter suppression and gust alleviation using active controls - Review of developments and applications based on the aerodynamic energy concept

    NASA Technical Reports Server (NTRS)

    Nissim, E.

    1978-01-01

    The state of the art of the aerodynamic energy concept, involving the use of active controls for flutter suppression, is reviewed. Applications of the concept include the suppression of external-store flutter of three different configurations of the YF-17 flutter model using a single trailing edge control surface activated by a single fixed-gain control law. Consideration is also given to some initial results concerning the flutter suppression of the 1/20 scale low speed wind-tunnel model of the Boeing 2707-300 supersonic transport using an activated trailing edge control surface.

  13. Learning about Chemistry Concepts. Superific Science Book VIII. A Good Apple Science Activity Book for Grades 5-8+.

    ERIC Educational Resources Information Center

    Conway, Lorraine

    Based on the idea that active participation stimulates the processes by which learning takes place, this document provides teachers and students with a variety of information and learning activities dealing with chemistry. Basic concepts about chemistry are presented through the use of laboratory experiments, demonstrations, worksheet exercises…

  14. Athletic Classmates, Physical Self-Concept, and Free-Time Physical Activity: A Longitudinal Study of Frame of Reference Effects

    ERIC Educational Resources Information Center

    Trautwein, Ulrich; Gerlach, Erin; Ludtke, Oliver

    2008-01-01

    The systematic analysis of factors that promote or impede physical activity in children is an urgent task for educational researchers. The present study investigated the reciprocal relationship between physical self-concept, teacher-assigned grades in physical education classes, and free-time physical activity, and analyzed positive and negative…

  15. Closed form expressions for crack mouth displacements and stress intensity factors for chevron notched short bar and short rod specimens based on experimental compliance measurements

    NASA Technical Reports Server (NTRS)

    Bubsey, R. T.; Orange, T. W.; Pierce, W. S.; Shannon, J. L., Jr.

    1992-01-01

    A set of equations are presented describing certain fracture mechanics parameters for chevron notch bar and rod specimens. They are developed by fitting compliance calibration data reported earlier. The equations present the various parameters in their most useful forms. The data encompass the entire range of the specimen geometries most commonly used. Their use will facilitate the testing and analysis of brittle metals, ceramics, and glasses.

  16. Experimental and Numerical Study on the Cracked Chevron Notched Semi-Circular Bend Method for Characterizing the Mode I Fracture Toughness of Rocks

    NASA Astrophysics Data System (ADS)

    Wei, Ming-Dong; Dai, Feng; Xu, Nu-Wen; Liu, Jian-Feng; Xu, Yuan

    2016-05-01

    The cracked chevron notched semi-circular bending (CCNSCB) method for measuring the mode I fracture toughness of rocks combines the merits (e.g., avoidance of tedious pre-cracking of notch tips, ease of sample preparation and loading accommodation) of both methods suggested by the International Society for Rock Mechanics, which are the cracked chevron notched Brazilian disc (CCNBD) method and the notched semi-circular bend (NSCB) method. However, the limited availability of the critical dimensionless stress intensity factor (SIF) values severely hinders the widespread usage of the CCNSCB method. In this study, the critical SIFs are determined for a wide range of CCNSCB specimen geometries via three-dimensional finite element analysis. A relatively large support span in the three point bending configuration was considered because the fracture of the CCNSCB specimen in that situation is finely restricted in the notch ligament, which has been commonly assumed for mode I fracture toughness measurements using chevron notched rock specimens. Both CCNSCB and NSCB tests were conducted to measure the fracture toughness of two different rock types; for each rock type, the two methods produce similar toughness values. Given the reported experimental results, the CCNSCB method can be reliable for characterizing the mode I fracture toughness of rocks.

  17. Unobtrusive behavioral and activity-related multimodal biometrics: The ACTIBIO Authentication concept.

    PubMed

    Drosou, A; Ioannidis, D; Moustakas, K; Tzovaras, D

    2011-01-01

    Unobtrusive Authentication Using ACTIvity-Related and Soft BIOmetrics (ACTIBIO) is an EU Specific Targeted Research Project (STREP) where new types of biometrics are combined with state-of-the-art unobtrusive technologies in order to enhance security in a wide spectrum of applications. The project aims to develop a modular, robust, multimodal biometrics security authentication and monitoring system, which uses a biodynamic physiological profile, unique for each individual, and advancements of the state of the art in unobtrusive behavioral and other biometrics, such as face, gait recognition, and seat-based anthropometrics. Several shortcomings of existing biometric recognition systems are addressed within this project, which have helped in improving existing sensors, in developing new algorithms, and in designing applications, towards creating new, unobtrusive, biometric authentication procedures in security-sensitive, Ambient Intelligence environments. This paper presents the concept of the ACTIBIO project and describes its unobtrusive authentication demonstrator in a real scenario by focusing on the vision-based biometric recognition modalities. PMID:21380485

  18. Dynamics of activation of semantically similar concepts during spoken word recognition.

    PubMed

    Mirman, Daniel; Magnuson, James S

    2009-10-01

    Semantic similarity effects provide critical insight into the organization of semantic knowledge and the nature of semantic processing. In the present study, we examined the dynamics of semantic similarity effects by using the visual world eyetracking paradigm. Four objects were shown on a computer monitor, and participants were instructed to click on a named object, during which time their gaze position was recorded. The likelihood of fixating competitor objects was predicted by the degree of semantic similarity to the target concept. We found reliable, graded competition that depended on degree of target-competitor similarity, even for distantly related items for which priming has not been found in previous priming studies. Time course measures revealed a consistently earlier fixation peak for near semantic neighbors relative to targets. Computational investigations with an attractor dynamical model, a spreading activation model, and a decision model revealed that a combination of excitatory and inhibitory mechanisms is required to obtain such peak timing, providing new constraints on models of semantic processing. PMID:19744941

  19. The mediating role of physical self-concept on relations between biological maturity status and physical activity in adolescent females.

    PubMed

    Cumming, Sean P; Standage, Martyn; Loney, Tom; Gammon, Catherine; Neville, Helen; Sherar, Lauren B; Malina, Robert M

    2011-06-01

    The current study examined the mediating role of physical self-concept on relations between biological maturity status and self-reported physical activity in adolescent British females. Biological maturity status, physical self-concept and physical activity were assessed in 407 female British year 7-9 pupils (M age = 13.2 years, SD = 1.0). Participants completed the Physical Activity Questionnaire for Adolescents (Kowalski, Crocker, & Donen, 2004) and the Children and Youth Physical Self-Perceptions Profile (Whitehead, 1995). Percentage of predicted adult height attained at measurement was used as an estimate of biological maturity status. Structural equation modelling using maximum likelihood estimation and bootstrapping procedures revealed that perceptions of sports competence, body attractiveness and physical self-worth mediated an inverse relation between maturity status and physical activity. The results provide partial support for Petersen and Taylor's (1980) Mediated Effects Model of Psychological and Behavioural Adaptation to Puberty within the context of physical activity. PMID:20655102

  20. Sustainability: Teaching an Interdisciplinary Threshold Concept through Traditional Lecture and Active Learning

    ERIC Educational Resources Information Center

    Levintova, Ekaterina M.; Mueller, Daniel W.

    2015-01-01

    One of the difficulties in teaching global sustainability in the introductory political science classes is the different emphases placed on this concept and the absence of the consensus on where the overall balance between environmental protection, economic development, and social justice should reside. Like many fuzzy concepts with which students…

  1. Foreign direct investment strategies: Least-developed countries and foreign firms. A case study of Sudan and Chevron Oil

    SciTech Connect

    Tom, B.M.

    1988-01-01

    The least-developed countries (LDCS) are politically underdeveloped. They often have autocratic authoritarian regimes that give less than appropriate attention to their societies' development. Being vulnerable and fairly unstable, such regimes are more occupied with their own survival than with developing pragmatic plans that cater to supplying their nations with missing economic resources needed through Foreign Direct Investment (FDI). Internal and external pressures on LDCS with such primitive political structures have greatly confused their leaderships and have resulted in the lack of institutionalization in these countries. Foreign firms normally choose to serve world markets through direct operations rather than exporting or licensing because the former maximize their gains more than the two other alternatives. This is why benefits to host countries may not match a host country's expectations when it allows FDI penetration. It is the contention of this research that Sudan failed to formulate a right policy towards FDI, and came short of maximizing its scarce resource returns. On the other hand, Chevron Oil, with a global overall profit-maximization strategy, succeeded in running its subsidiary in Sudan in accordance with its global outlook.

  2. Turbulent Flow Field Measurements of Separate Flow Round and Chevron Nozzles with Pylon Interaction Using Particle Image Velocimetry

    NASA Technical Reports Server (NTRS)

    Doty, Michael J.; Henerson, Brenda S.; Kinzie, Kevin W.

    2004-01-01

    Particle Image Velocimetry (PIV) measurements for six separate flow bypass ratio five nozzle configurations have recently been obtained in the NASA Langley Jet Noise Laboratory. The six configurations include a baseline configuration with round core and fan nozzles, an eight-chevron core nozzle at two different clocking positions, and repeats of these configurations with a pylon included. One run condition representative of takeoff was investigated for all cases with the core nozzle pressure ratio set to 1.56 and the total temperature to 828 K. The fan nozzle pressure ratio was set to 1.75 with a total temperature of 350 K, and the freestream Mach number was M = 0.28. The unsteady flow field measurements provided by PIV complement recent computational, acoustic, and mean flow field studies performed at NASA Langley for the same nozzle configurations and run condition. The PIV baseline configuration measurements show good agreement with mean flow field data as well as existing PIV data acquired at NASA Glenn. Nonetheless, the baseline configuration turbulence profile indicates an asymmetric flow field, despite careful attention to concentricity. The presence of the pylon increases the upper shear layer turbulence levels while simultaneously decreasing the turbulence levels in the lower shear layer. In addition, a slightly shorter potential core length is observed with the addition of the pylon. Finally, comparisons of computational results with PIV measurements are favorable for mean flow, slightly over-predicted for Reynolds shear stress, and underpredicted for Reynolds normal stress components.

  3. Fracture Toughness Determination of Cracked Chevron Notched Brazilian Disc Rock Specimen via Griffith Energy Criterion Incorporating Realistic Fracture Profiles

    NASA Astrophysics Data System (ADS)

    Xu, Yuan; Dai, Feng; Zhao, Tao; Xu, Nu-wen; Liu, Yi

    2016-08-01

    The cracked chevron notched Brazilian disc (CCNBD) specimen has been suggested by the International Society for Rock Mechanics to measure the mode I fracture toughness of rocks, and has been widely adopted in laboratory tests. Nevertheless, a certain discrepancy has been observed in results when compared with those derived from methods using straight through cracked specimens, which might be due to the fact that the fracture profiles of rock specimens cannot match the straight through crack front as assumed in the measuring principle. In this study, the progressive fracturing of the CCNBD specimen is numerically investigated using the discrete element method (DEM), aiming to evaluate the impact of the realistic cracking profiles on the mode I fracture toughness measurements. The obtained results validate the curved fracture fronts throughout the fracture process, as reported in the literature. The fracture toughness is subsequently determined via the proposed G-method originated from Griffith's energy theory, in which the evolution of the realistic fracture profile as well as the accumulated fracture energy is quantified by DEM simulation. A comparison between the numerical tests and the experimental results derived from both the CCNBD and the semi-circular bend (SCB) specimens verifies that the G-method incorporating realistic fracture profiles can contribute to narrowing down the gap between the fracture toughness values measured via the CCNBD and the SCB method.

  4. NASA Propulsion Sub-System Concept Studies and Risk Reduction Activities for Resource Prospector Lander

    NASA Technical Reports Server (NTRS)

    Trinh, Huu P.

    2015-01-01

    NASA's exploration roadmap is focused on developing technologies and performing precursor missions to advance the state of the art for eventual human missions to Mars. One of the key components of this roadmap is various robotic missions to Near-Earth Objects, the Moon, and Mars to fill in some of the strategic knowledge gaps. The Resource Prospector (RP) project is one of these robotic precursor activities in the roadmap. RP is a multi-center and multi-institution project to investigate the polar regions of the Moon in search of volatiles. The mission is rated Class D and is approximately 10 days, assuming a five day direct Earth to Moon transfer. Because of the mission cost constraint, a trade study of the propulsion concepts was conducted with a focus on available low-cost hardware for reducing cost in development, while technical risk, system mass, and technology advancement requirements were also taken into consideration. The propulsion system for the lander is composed of a braking stage providing a high thrust to match the lander's velocity with the lunar surface and a lander stage performing the final lunar descent. For the braking stage, liquid oxygen (LOX) and liquid methane (LCH4) propulsion systems, derived from the Morpheus experimental lander, and storable bi-propellant systems, including the 4th stage Peacekeeper (PK) propulsion components and Space Shuttle orbital maneuvering engine (OME), and a solid motor were considered for the study. For the lander stage, the trade study included miniaturized Divert Attitude Control System (DACS) thrusters (Missile Defense Agency (MDA) heritage), their enhanced thruster versions, ISE-100 and ISE-5, and commercial-off-the-shelf (COTS) hardware. The lowest cost configuration of using the solid motor and the PK components while meeting the requirements was selected. The reference concept of the lander is shown in Figure 1. In the current reference configuration, the solid stage is the primary provider of delta

  5. Supersonic jet noise prediction and noise source investigation for realistic baseline and chevron nozzles based on hybrid RANS/LES simulations

    NASA Astrophysics Data System (ADS)

    Du, Yongle

    Jet noise simulations have been performed for a military-style baseline nozzle and a chevron nozzle with design Mach numbers of Md = 1:5 operating at several off-design conditions. The objective of the current numerical study is to provide insight into the noise generation mechanisms of shock-containing supersonic hot jets and the noise reduction mechanisms of chevron nozzles. A hybrid methodology combining advanced CFD technologies and the acoustic analogy is used for supersonic jet noise simulations. Unsteady Reynolds-averaged Navier-Stokes (URANS) equations are solved to predict the turbulent noise sources in the jet flows. A modified version of the Detached Eddy Simulation (DES) approach is used to avoid excessive damping of fine scale turbulent fluctuations. A multiblock structured mesh topology is used to represent complex nozzle geometries, including the faceted inner contours and finite nozzle thickness. A block interface condition is optimized for the complex multiblock mesh topology to avoid the centerline singularity. A fourth-order Dispersion-Relation-Preserving (DRP) scheme is used for spatial discretization. To enable efficient calculations, a dual time-stepping method is used in addition to parallel computation using MPI. Both multigrid and implicit residual smoothing are used to accelerate the convergence rate of sub-iterations in the fictitious time domain. Noise predictions are made with the permeable surface Ffowcs Williams and Hawkings (FWH) solution. All the numerical methods have been implemented in the jet flow simulation code "CHOPA" and the noise prediction code "PSJFWH". The computer codes have been validated with several benchmark cases. A preliminary study has been performed for an under-expanded baseline nozzle jet with Mj = 1:56 to validate the accuracy of the jet noise simulations. The results show that grid refinement around the jet potential core and the use of a lower artificial dissipation improve the resolution of the predicted

  6. Taming Test Anxiety: The Activation of Failure-Related Concepts Enhances Cognitive Test Performance of Test-Anxious Students

    ERIC Educational Resources Information Center

    Tempel, Tobias; Neumann, Roland

    2016-01-01

    We investigated processes underlying performance decrements of highly test-anxious persons. Three experiments contrasted conditions that differed in the degree of activation of concepts related to failure. Participants memorized a list of words either containing words related to failure or containing no words related to failure in Experiment 1. In…

  7. The Effects of Problem-Based Active Learning in Science Education on Students' Academic Achievement, Attitude and Concept Learning

    ERIC Educational Resources Information Center

    Akinoglu, Orhan; Tandogan, Ruhan Özkardes

    2007-01-01

    The aim of this study was to determine the effects of problem-based active learning in science education on students' academic achievement and concept learning. In the study, both quantitative and qualitative research methods were utilized. Quantitative data were obtained via the pre/post-test, treatment-control groups test model. Qualitative data…

  8. Making the Economic Concept of Scarcity Oh-so-Sweet: An Activity for the K-12 Classroom

    ERIC Educational Resources Information Center

    Marks, Melanie; Davis, Cheryl

    2006-01-01

    The authors outline an innovative activity that helps teachers make the abstract concepts of scarcity and allocation concrete in the K-12 classroom. Students evaluate the scarcity of chocolate and often determine, incorrectly, that the candy is not scarce because there is enough for each student to have one piece. After students reveal their…

  9. School-Based Extracurricular Activities, Personality, Self-Concept, and College Career Development Skills in Chinese Society

    ERIC Educational Resources Information Center

    Shiah, Yung-Jong; Huang, Ying; Chang, Frances; Chang, Chuan-Feng; Yeh, Lun-Chang

    2013-01-01

    In the present study, we examined in Chinese society the association of school-based extracurricular activities (SBEAs) in both high school and college with students' career development skills in college, as well as with various personality characteristics and self-concept. Each of 281 college students administered the Lai Personality Inventory,…

  10. Concept of an Active Amplification Mechanism in the Infrared Organ of Pyrophilous Melanophila Beetles

    PubMed Central

    Schneider, Erik S.; Schmitz, Anke; Schmitz, Helmut

    2015-01-01

    Jewel beetles of the genus Melanophila possess a pair of metathoracic infrared (IR) organs. These organs are used for forest fire detection because Melanophila larvae can only develop in fire killed trees. Several reports in the literature and a modeling of a historic oil tank fire suggest that beetles may be able to detect large fires by means of their IR organs from distances of more than 100 km. In contrast, the highest sensitivity of the IR organs, so far determined by behavioral and physiological experiments, allows a detection of large fires from distances up to 12 km only. Sensitivity thresholds, however, have always been determined in non-flying beetles. Therefore, the complete micromechanical environment of the IR organs in flying beetles has not been taken into consideration. Because the so-called photomechanic sensilla housed in the IR organs respond bimodally to mechanical as well as to IR stimuli, it is proposed that flying beetles make use of muscular energy coupled out of the flight motor to considerably increase the sensitivity of their IR sensilla during intermittent search flight sequences. In a search flight the beetle performs signal scanning with wing beat frequency while the inputs of the IR organs on both body sides are compared. By this procedure the detection of weak IR signals could be possible even if the signals are hidden in the thermal noise. If this proposed mechanism really exists in Melanophila beetles, their IR organs could even compete with cooled IR quantum detectors. The theoretical concept of an active amplification mechanism in a photon receptor innervated by highly sensitive mechanoreceptors is presented in this article. PMID:26733883

  11. Developmental experiences during extracurricular activities and Australian adolescents' self-concept: particularly important for youth from disadvantaged schools.

    PubMed

    Blomfield, Corey J; Barber, Bonnie L

    2011-05-01

    Extracurricular activities provide adolescents with a number of positive personal and interpersonal developmental experiences. This study investigated whether developmental experiences that occurred during extracurricular activities were linked to a more positive self-concept for Australian adolescents, and whether this link was particularly salient for youth from disadvantaged schools. Adolescents (N = 1,504, 56% Female) from 26 diverse high schools across Western Australia were surveyed. The findings revealed that adolescents from low socio-economic status schools who participated in extracurricular activities had a more positive general self-worth and social self-concept than adolescents from similar socio-economic schools who did not participate in any extracurricular activities. Furthermore, the positive developmental experiences that occurred during extracurricular activities predicted a more positive general self-worth and social and academic self-concept, and this link was stronger for youth from low SES schools. These findings suggest that the developmental experiences afforded by extracurricular activities may foster positive adolescent development.

  12. Prior Knowledge Activation: How Different Concept Mapping Tasks Lead to Substantial Differences in Cognitive Processes, Learning Outcomes, and Perceived Self-Efficacy

    ERIC Educational Resources Information Center

    Gurlitt, Johannes; Renkl, Alexander

    2010-01-01

    Two experiments investigated the effects of characteristic features of concept mapping used for prior knowledge activation. Characteristic demands of concept mapping include connecting lines representing the relationships between concepts and labeling these lines, specifying the type of the semantic relationships. In the first experiment,…

  13. Computational studies of the effects of active and passive circulation enhancement concepts on wind turbine performance

    NASA Astrophysics Data System (ADS)

    Tongchitpakdee, Chanin

    With the advantage of modern high speed computers, there has been an increased interest in the use of first-principles based computational approaches for the aerodynamic modeling of horizontal axis wind turbine (HAWT). Since these approaches are based on the laws of conservation (mass, momentum, and energy), they can capture much of the physics in great detail. The ability to accurately predict the airloads and power output can greatly aid the designers in tailoring the aerodynamic and aeroelastic features of the configuration. First-principles based analyses are also valuable for developing active means (e.g., circulation control), and passive means (e.g., Gurney flaps) of reducing unsteady blade loads, mitigating stall, and for efficient capture of wind energy leading to more electrical power generation. In this present study, the aerodynamic performance of a wind turbine rotor equipped with circulation enhancement technology (trailing edge blowing or Gurney flaps) is investigated using a three-dimensional unsteady viscous flow analysis. The National Renewable Energy Laboratory (NREL) Phase VI horizontal axis wind turbine is chosen as the baseline configuration. Prior to its use in exploring these concepts, the flow solver is validated with the experimental data for the baseline case under yawed flow conditions. Results presented include radial distribution of normal and tangential forces, shaft torque, root flap moment, surface pressure distributions at selected radial locations, and power output. Results show that good agreement has been for a range of wind speeds and yaw angles, where the flow is attached. At high wind speeds, however, where the flow is fully separated, it was found that the fundamental assumptions behind this present methodology breaks down for the baseline turbulence model (Spalart-Allmaras model), giving less accurate results. With the implementation of advanced turbulence model, Spalart-Allmaras Detached Eddy Simulation (SA-DES), the

  14. Transforming a Traditional Hands-On Activity into an Enquiry Activity to Foster More In-Depth Understanding of the Concept of Density

    ERIC Educational Resources Information Center

    Lee, Yeung Chung; Kwok, Ping Wai

    2010-01-01

    Traditional methods used to teach the concept of density that employ solid objects of different masses and volumes can be supplemented by enquiry activities in which students vary the mass-to-volume ratio of the same object to test ideas about density and flotation. A simple substance, Blu-Tack, is an ideal material to use in this case. The…

  15. Peer Assessment as a Collaborative Learning Activity: The Role of Interpersonal Variables and Conceptions

    ERIC Educational Resources Information Center

    van Gennip, Nanine A. E.; Segers, Mien S. R.; Tillema, Harm H.

    2010-01-01

    The present study examined the role of interpersonal variables (psychological safety, value diversity, interdependence, and trust) and conceptions of peer assessment in vocational education. An intervention was conducted (N=45) with a control group (N=17), which indicated change in psychological safety, value diversity, and trust in the peer as an…

  16. Activity-Based Restorative Therapies: Concepts and Applications in Spinal Cord Injury-Related Neurorehabilitation

    ERIC Educational Resources Information Center

    Sadowsky, Cristina L.; McDonald, John W.

    2009-01-01

    Physical rehabilitation following spinal cord injury-related paralysis has traditionally focused on teaching compensatory techniques, thus enabling the individual to achieve day-to-day function despite significant neurological deficits. But the concept of an irreparable central nervous system (CNS) is slowly being replaced with evidence related to…

  17. Renal Clearance: Using an Interactive Activity to Visualize a Tricky Concept

    ERIC Educational Resources Information Center

    Hull, Kerry

    2016-01-01

    Renal clearance, the volume of blood cleared of a substance in a particular time period, is commonly recognized as one of the most difficult concepts in physiology. This difficulty may in part reflect the quantitative nature of renal clearance since many life sciences majors perceive that mathematics is irrelevant to their discipline. Students may…

  18. Specific Antivirulence Activity, A New Concept for Reliable Screening of Virulence Inhibitors.

    PubMed

    Defoirdt, Tom

    2016-07-01

    Antivirulence therapy, disarming pathogens rather than killing them, is emerging as a novel strategy for disease control. Reporter strains expressing an easily measurable and quantifiable phenotype enable easy screening of virulence inhibitors. In this paper I propose a novel concept to exclude false positives in this type of screening. PMID:26879186

  19. Solar power satellite. Concept evaluation. Activities report. Volume 2: Detailed report

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Comparative data are presented among various design approaches to thermal engine and photovoltaic SPS (Solar Power System) concepts, to provide criteria for selecting the most promising systems for more detailed definition. The major areas of the SPS system to be examined include solar cells, microwave power transmission, transportation, structure, rectenna, energy payback, resources, and environmental issues.

  20. Controle sismique d'un batiment en acier de 3 etages a l'echelle 1/3 par amortisseurs elastomeres et contreventements en chevron

    NASA Astrophysics Data System (ADS)

    Gauron, Olivier

    This study develops an innovative configuration of seismic natural rubber dampers for multistory low- and medium-rise steel braced frames. The dampers are directly integrated in an horizontal position in the seismic force resisting system of the structure. They are connected in a series with typical chevron brace systems. This control system provides not only additional structural damping to the structure but also a period shift, acting in the same way as a base isolation system. First, the fiber reinforced natural rubber used in the application was tested. It exhibited strong non linear dependance of its equivalent viscoelastic properties related to the shear strain. Then, a 1/3-scale 3-story chevron braced steel frame with and without dampers was considered. The structure was build and placed on the shaking table of the University of Sherbrooke Structures Laboratory. Numerical studies show that the efficiency of the control system reduces strongly the seismic induced forces of the undamped structure without any amplification of displacement or drift. Obtained seismic response reduction levels represent significant safety and economical benefits for the proposed application. Finally, the control system viability is experimentally demonstrated by shaking table tests at different reduced seismic intensities. Non linear behavior of the structure due to non linear behavior of the damping material is highlighted, and the dependance of seismic control performances is shown to be related to seismic intensities. Results allow an extrapolation of the experimental control peformances tending to the numerical results at higher intensities. Key-words : chevron braces, damper, multistory building, natural rubber, seismic control, shaking table.

  1. An Active Flow Circulation Controlled Flap Concept for General Aviation Aircraft Applications

    NASA Technical Reports Server (NTRS)

    Jones, Gregory S.; Viken, Sally A.; Washburn, Anthony E.; Jenkins, Luther N.; Cagle, C. Mark

    2002-01-01

    A recent focus on revolutionary aerodynamic concepts has highlighted the technology needs of general aviation and personal aircraft. New and stringent restrictions on these types of aircraft have placed high demands on aerodynamic performance, noise, and environmental issues. Improved high lift performance of these aircraft can lead to slower takeoff and landing speeds that can be related to reduced noise and crash survivability issues. Circulation Control technologies have been around for 65 years, yet have been avoided due to trade offs of mass flow, pitching moment, perceived noise etc. The need to improve the circulation control technology for general aviation and personal air-vehicle applications is the focus of this paper. This report will describe the development of a 2-D General Aviation Circulation Control (GACC) wing concept that utilizes a pulsed pneumatic flap.

  2. Inorganic concepts relevant to metal binding, activity, and toxicity in a biological system

    SciTech Connect

    Hoeschele, J.D. . Parke-Davis Pharmaceutical Research Div.); Turner, J.E.; England, M.W. )

    1990-01-01

    The purpose of this paper is to review selected physical and inorganic concepts and factors which might be important in assessing and/or understanding the fact and disposition of a metal system in a biological environment. Hopefully, such inquiries will ultimately permit us to understand, rationalize, and predict differences and trends in biological effects as a function of the basic nature of a metal system and, in optimal cases, serve as input to a system of guidelines for the notion of Chemical Dosimetry.'' The plan of this paper is to first review, in general terms, the basic principles of the Crystal Field Theory (CFT), a unifying theory of bonding in metal complexes. This will provide the necessary theoretical background for the subsequent discussion of selected concepts and factors. 21 refs., 7 figs., 6 tabs.

  3. Active Removal of Large Debris: System Approach of Desorbiting Concepts and Technological Issues

    NASA Astrophysics Data System (ADS)

    Couzin, Patrice; Rembala, Richard; Teti, Frank; Bakouche, Charles; Billot, Carole

    2013-08-01

    The threat induced by large space debris, dead satellites or rocket bodies, in Low Earth Orbit has been identified years ago. A first part of the Orbital Transfer Vehicle (OTV) study was dedicated to identify mission architectures that can fulfil the objective to eliminate the necessary number of critical debris. Those potential solutions and architectures have been compared taking into account cost considerations. The present paper reports the first results of the OTV step2 study funded by CNES that addresses different solutions for large debris removal. It compares different desorbiting concepts from selected single to multiple debris complying with the Space Law, i.e. able to ensure controlled re entries. Different capture options are presented, including sensors needs and an analysis of the problems posed by different solutions. The overall performances of the concepts are compared, showing the adequacy, the limits of each solutions and application domains.

  4. Laboratory activity to effectively teach introductory geomicrobiology concepts to non-geology majors.

    PubMed

    Marvasi, Massimiliano; Davila-Vazquez, Yarely C; Martinez, Lilliam Casillas

    2013-01-01

    We have designed a three-week experiment that can complement any microbiology course, to teach main geomicrobiology concepts for non-geology majors. One of the most difficult concepts for non-geology majors to comprehend is how bacteria serve as a platform for different mineralization reactions. In our three-week laboratory practice, students learn the main principles and conditions required for an induced bacterial mineralization. Upon completion of the laboratory experience, students will: 1) learn how microbial-induced mineralization (such as calcium carbonate formation) is affected by differential media and growth conditions; 2) understand how bacterial physiology affects any induced in situ or in vitro mineralization; 3) comprehend how growing conditions and bacterial physiologies interrelate, resulting in differential crystal formation. The teaching-learning process was assessed using a pre-/posttest with an increase from 26% to 76% in the number of positive answers from the students. We also measured the students' proficiency while conducting specific technical tasks, revealing no major difficulties while conducting the experiments. A final questionnaire was provided with satisfactory evaluations from the students regarding the organization and content of the practices. 84-86% of the students agreed that the exercises improved their knowledge in geomicrobiology and would like to attend similar laboratories in the future. Such response is the best indicator that the laboratory practice can be implemented in any undergraduate/graduate microbiology course to effectively teach basic geomicrobiology concepts to non-geology majors. PMID:24358384

  5. Laboratory activity to effectively teach introductory geomicrobiology concepts to non-geology majors.

    PubMed

    Marvasi, Massimiliano; Davila-Vazquez, Yarely C; Martinez, Lilliam Casillas

    2013-01-01

    We have designed a three-week experiment that can complement any microbiology course, to teach main geomicrobiology concepts for non-geology majors. One of the most difficult concepts for non-geology majors to comprehend is how bacteria serve as a platform for different mineralization reactions. In our three-week laboratory practice, students learn the main principles and conditions required for an induced bacterial mineralization. Upon completion of the laboratory experience, students will: 1) learn how microbial-induced mineralization (such as calcium carbonate formation) is affected by differential media and growth conditions; 2) understand how bacterial physiology affects any induced in situ or in vitro mineralization; 3) comprehend how growing conditions and bacterial physiologies interrelate, resulting in differential crystal formation. The teaching-learning process was assessed using a pre-/posttest with an increase from 26% to 76% in the number of positive answers from the students. We also measured the students' proficiency while conducting specific technical tasks, revealing no major difficulties while conducting the experiments. A final questionnaire was provided with satisfactory evaluations from the students regarding the organization and content of the practices. 84-86% of the students agreed that the exercises improved their knowledge in geomicrobiology and would like to attend similar laboratories in the future. Such response is the best indicator that the laboratory practice can be implemented in any undergraduate/graduate microbiology course to effectively teach basic geomicrobiology concepts to non-geology majors.

  6. Creative Concept Mapping.

    ERIC Educational Resources Information Center

    Brown, David S.

    2002-01-01

    Recommends the use of concept mapping in science teaching and proposes that it be presented as a creative activity. Includes a sample lesson plan of a potato stamp concept mapping activity for astronomy. (DDR)

  7. ``Greener Shade of Ruthenium'': New Concepts of Activation, Immobilization, and Recovery of Ruthenium Catalysts For Green Olefin Metathesis

    NASA Astrophysics Data System (ADS)

    Michrowska, Anna; Gulajski, Lukasz; Grela, Karol

    The results described herewith demonstrate that the activity of ruthenium (Ru) metathesis catalysts can be enhanced by introduction of electron-withdrawing groups (EWGs) without detriment to catalysts stability. This principle can be used not only to increase the catalyst activity, but also to alter its physical-chemical properties, such as solubility in given medium or affinity to silica gel. An example of novel immobilisation strategy, based on this concept is presented. The ammonium-tagged Hoveyda-type catalysts can be successfully applied in aqueous media as well as in ionic liquids (IL). Substitution of a benzylidene fragment can be used not only to immobilize the organometallic complex in such media, but also to increase its catalytic activity by electronic activation. The high stability and good application profiles of such modified catalysts in conjunction with their facile removal from organic products can be expected to offer new opportunities in green applications of olefin metathesis.

  8. Test Rig for Evaluating Active Turbine Blade Tip Clearance Control Concepts

    NASA Technical Reports Server (NTRS)

    Lattime, Scott B.; Steinetz, Bruce M.; Robbie, Malcolm G.; Erker, Arthur H.

    2004-01-01

    The objectives of the research presented in this viewgraph presentation are to 1) Design a mechanical ACC system for HPT tip seal clearance management; 2) Design a test rig to evaluate ACC system concepts. We have focused our efforts on designing mechanical ACC systems that articulate the seal shroud via mechanical linkages connected to actuators that reside outside the extreme environment of the HPT. We opted for this style of design due to a lack of high temperature/low profile actuators that are presently available. We have also selected multiple hydraulic actuators for this first generation ACC system. Fuel-draulic actuators are already a well established technology.

  9. Public open space, physical activity, urban design and public health: Concepts, methods and research agenda.

    PubMed

    Koohsari, Mohammad Javad; Mavoa, Suzanne; Villanueva, Karen; Sugiyama, Takemi; Badland, Hannah; Kaczynski, Andrew T; Owen, Neville; Giles-Corti, Billie

    2015-05-01

    Public open spaces such as parks and green spaces are key built environment elements within neighbourhoods for encouraging a variety of physical activity behaviours. Over the past decade, there has been a burgeoning number of active living research studies examining the influence of public open space on physical activity. However, the evidence shows mixed associations between different aspects of public open space (e.g., proximity, size, quality) and physical activity. These inconsistencies hinder the development of specific evidence-based guidelines for urban designers and policy-makers for (re)designing public open space to encourage physical activity. This paper aims to move this research agenda forward, by identifying key conceptual and methodological issues that may contribute to inconsistencies in research examining relations between public open space and physical activity.

  10. Public open space, physical activity, urban design and public health: Concepts, methods and research agenda.

    PubMed

    Koohsari, Mohammad Javad; Mavoa, Suzanne; Villanueva, Karen; Sugiyama, Takemi; Badland, Hannah; Kaczynski, Andrew T; Owen, Neville; Giles-Corti, Billie

    2015-05-01

    Public open spaces such as parks and green spaces are key built environment elements within neighbourhoods for encouraging a variety of physical activity behaviours. Over the past decade, there has been a burgeoning number of active living research studies examining the influence of public open space on physical activity. However, the evidence shows mixed associations between different aspects of public open space (e.g., proximity, size, quality) and physical activity. These inconsistencies hinder the development of specific evidence-based guidelines for urban designers and policy-makers for (re)designing public open space to encourage physical activity. This paper aims to move this research agenda forward, by identifying key conceptual and methodological issues that may contribute to inconsistencies in research examining relations between public open space and physical activity. PMID:25779691

  11. H2Oh!: Classroom demonstrations and activities for improving student learning of water concepts

    NASA Astrophysics Data System (ADS)

    Chan-Hilton, A.; Neupauer, R. M.; Burian, S. J.; Lauer, J. W.; Mathisen, P. P.; Mays, D. C.; Olson, M. S.; Pomeroy, C. A.; Ruddell, B. L.; Sciortino, A.

    2012-12-01

    Research has shown that the use of demonstrations and hands-on activities in the classroom enhances student learning. Students learn more and enjoy classes more when visual and active learning are incorporated into the lecture. Most college-aged students prefer visual modes of learning, while most instruction is conducted in a lecture, or auditory, format. The use of classroom demonstrations provides opportunities for incorporating visual and active learning into the classroom environment. However, while most instructors acknowledge the benefits of these teaching methods, they typically do not have the time and resources to develop and test such activities and to develop plans to incorporate them into their lectures. Members of the Excellence in Water Resources Education Task Committee of the Environmental and Water Resources Institute (EWRI) of the American Society of Civil Engineers (ASCE) have produced a publication that contains a collection of activities aimed to foster excellence in water resources and hydrology education and improve student learning of principles. The book contains forty-five demonstrations and activities that can be used in water-related classes with topics in fluid mechanics, hydraulics, surface water hydrology, groundwater hydrology, and water quality. We present examples of these activities, including topics such as conservation of momentum, buoyancy, Bernoulli's principle, drag force, pipe flow, watershed delineation, reservoir networks, head distribution in aquifers, and molecular diffusion in a porous medium. Unlike full laboratory exercises, these brief demonstrations and activities (most of which take less than fifteen minutes) can be easily incorporated into classroom lectures. For each demonstration, guidance for preparing and conducting the activity, along with a brief overview of the principles that are demonstrated, is provided. The target audience of the activities is undergraduate students, although the activities also may be

  12. Using Active Learning to Teach Concepts and Methods in Quantitative Biology.

    PubMed

    Waldrop, Lindsay D; Adolph, Stephen C; Diniz Behn, Cecilia G; Braley, Emily; Drew, Joshua A; Full, Robert J; Gross, Louis J; Jungck, John A; Kohler, Brynja; Prairie, Jennifer C; Shtylla, Blerta; Miller, Laura A

    2015-11-01

    This article provides a summary of the ideas discussed at the 2015 Annual Meeting of the Society for Integrative and Comparative Biology society-wide symposium on Leading Students and Faculty to Quantitative Biology through Active Learning. It also includes a brief review of the recent advancements in incorporating active learning approaches into quantitative biology classrooms. We begin with an overview of recent literature that shows that active learning can improve students' outcomes in Science, Technology, Engineering and Math Education disciplines. We then discuss how this approach can be particularly useful when teaching topics in quantitative biology. Next, we describe some of the recent initiatives to develop hands-on activities in quantitative biology at both the graduate and the undergraduate levels. Throughout the article we provide resources for educators who wish to integrate active learning and technology into their classrooms.

  13. Research-Concept Evaluation

    NASA Technical Reports Server (NTRS)

    White, M. J.; Kolb, W.

    1985-01-01

    Concepts ranked according to potential benefit/cost ratios. ARINC Researh Concept Evaluation Methodology (ARCEM) program provides powerful tool for organization and planning of research activities indicating which concepts provide greatest benefit for investment and determines number of concepts implemented to justify expenditures for development of generic technologies.

  14. Design and Control of a Proof-of-Concept Active Jet Engine Intake Using Shape Memory Alloy Actuators

    NASA Technical Reports Server (NTRS)

    Song, Gangbing; Ma, Ning; Penney, Nicholas; Barr, Todd; Lee, Ho-Jun; Arnold, Steven M.

    2004-01-01

    The design and control of a novel proof-of-concept active jet engine intake using Nickel-Titanium (Ni-Ti or Nitinol) shape memory alloy (SMA) wire actuators is used to demonstrate the potential of an adaptive intake to improve the fuel efficiency of a jet engine. The Nitinol SMA material is selected for this research due to the material's ability to generate large strains of up to 5 percent for repeated operations, a high power-to-weight ratio, electrical resistive actuation, and easy fabrication into a variety of shapes. The proof-of-concept engine intake employs an overlapping leaf design arranged in a concentric configuration. Each leaf is mounted on a supporting bar that rotates upon actuation by SMA wires electrical resistive heating. Feedback control is enabled through the use of a laser range sensor to detect the movement of a leaf and determine the radius of the intake area. Due to the hysteresis behavior inherent in SMAs, a nonlinear robust controller is used to direct the SMA wire actuation. The controller design utilizes the sliding-mode approach to compensate for the nonlinearities associated with the SMA actuator. Feedback control experiments conducted on a fabricated proof-of-concept model have demonstrated the capability to precisely control the intake area and achieve up to a 25 percent reduction in intake area. The experiments demonstrate the feasibility of engine intake area control using the proposed design.

  15. Exercise as Medicine: Key Concepts in Discussing Physical Activity with Patients who have Type 2 Diabetes.

    PubMed

    Armstrong, Marni J; Sigal, Ronald J

    2015-12-01

    People with type 2 diabetes stand to benefit substantially from being physically active. Practice guidelines consistently recommend that people with diabetes obtain at least 150 minutes of moderate to vigorous aerobic exercise per week. Although the message of 150 minutes per week is important, there are several other key messages regarding physical activity that may not be communicated as often or as clearly. This article gives an overview of the importance of resistance training, the dose-response relationship between physical activity and health outcomes, and the emerging evidence concerning the role of sedentary behavior in people with type 2 diabetes. This article provides valuable content for healthcare providers that will help to inform their discussions about physical activity with patients who have type 2 diabetes.

  16. Active latent heat storage with a screw heat exchanger - experimental results for heat transfer and concept for high pressure steam

    NASA Astrophysics Data System (ADS)

    Zipf, Verena; Willert, Daniel; Neuhäuser, Anton

    2016-05-01

    An innovative active latent heat storage concept was invented and developed at Fraunhofer ISE. It uses a screw heat exchanger (SHE) for the phase change during the transport of a phase change material (PCM) from a cold to a hot tank or vice versa. This separates heat transfer and storage tank in comparison to existing concepts. A test rig has been built in order to investigate the heat transfer coefficients of the SHE during melting and crystallization of the PCM. The knowledge of these characteristics is crucial in order to assess the performance of the latent heat storage in a thermal system. The test rig contains a double shafted SHE, which is heated or cooled with thermal oil. The overall heat transfer coefficient U and the convective heat transfer coefficient on the PCM side hPCM both for charging and discharging have been calculated based on the measured data. For charging, the overall heat transfer coefficient in the tested SHE was Uch = 308 W/m2K and for discharging Udis = 210 W/m2K. Based on the values for hPCM the overall heat transfer coefficients for a larger SHE with steam as heat transfer fluid and an optimized geometry were calculated with Uch = 320 W/m2K for charging and Udis = 243 W/m2K for discharging. For pressures as high as p = 100 bar, an SHE concept has been developed, which uses an organic fluid inside the flight of the SHE as working media. With this concept, the SHE can also be deployed for very high pressure, e.g. as storage in solar thermal power plants.

  17. Accelerated development and flight evaluation of active controls concepts for subsonic transport aircraft

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The flight test of an active load alleviation/extended span for the L-1011 wide-body transport aircraft, and piloted simulation work leading to use of active stability augmentation with a small tail and aft center of gravity are reported. The extended span showed the expected cruise drag reduction of 3%. The small tail is expected to reduce cruise drag by another 3%, and eventual use of more aft center of gravity with active stability augmentation will provide further fuel savings. The active load alleviation functions included maneuver load control (MLC) and elastic mode suppression (EMS), using symmetric motions of the outboard ailerons to reduce wing bending loads in maneuvers or long-term up- or down-drafts (MLC), and to damp wing bending motions in turbulence (EMS). A gust load alleviation function using the active horizontal tail to provide airplane pitch damping in turbulence was found unnecessary. The piloted simulation tests evaluated criteria for augmentation-on and augmentation-off flying qualities. of a simple pitch control law was verified at neutral static margin. The simulation tasks established the basis for follow-on construction and flight testing of a small tail with active stability augmentation.

  18. Personalized foot orthoses with embedded temperature sensing: Proof of concept and relationship with activity.

    PubMed

    Telfer, Scott; Munguia, Javier; Pallari, Jari; Dalgarno, Kenneth; Steultjens, Martijn; Woodburn, James

    2014-01-01

    Plantar foot surface temperature has been identified as a clinically relevant physiological variable. Embedding sensors in foot orthoses (FOs) may allow long term monitoring of these temperatures, with compliance via the detection of periods of activity being a potential clinical utilization. This study aimed to test novel designs for FOs with embedded sensing that were produced via additive manufacturing and determine if foot temperature measurements could be used to detect periods of increased activity. FOs with embedded temperature sensors were developed and tested in 10 healthy participants over four day wear periods. Activity monitoring was used to estimate energy expenditure during testing. A threshold-based algorithm was developed to identify time periods of high activity from foot temperature data. Group differences in estimated energy expenditure between time periods below and above the threshold were significant in both the training and validation sets (p<0.001). Significant differences were also seen at individual participant level (p<0.001 in all cases). These results demonstrate the feasibility of using FOs with embedded sensing to monitor plantar surface foot temperatures during normal daily activities and for extended periods and show that periods of increased activity can be identified using foot temperature data. PMID:23981438

  19. Application of the aerodynamic energy concept to flutter suppression and gust alleviation by use of active controls

    NASA Technical Reports Server (NTRS)

    Nissim, E.; Caspi, A.; Lottati, I.

    1976-01-01

    The effects of active controls on flutter suppression and gust alleviation of the Arava twin turboprop STOL transport and the Westwind twinjet business transport are investigated. The active control surfaces are introduced in pairs which include, in any chosen wing strip, a 20-percent chord leading-edge control and a 20-percent chord trailing-edge control. Each control surface is driven by a combined linear-rotational sensor system located on the activated strip. The control law is based on the concept of aerodynamic energy and utilizes previously optimized control law parameters based on two-dimensional aerodynamic theory. The best locations of the activated system along the span of the wing are determined for bending-moment alleviation, reduction in fuselage accelerations, and flutter suppression. The effectiveness of the activated system over a wide range of maximum control deflections is also determined. Two control laws are investigated. The first control law utilizes both rigid-body and elastic contributions of the motion. The second control law employs primarily the elastic contribution of the wing and leads to large increases in the activated control effectiveness as compared with the basic control law. The results indicate that flutter speed can be significantly increased (over 70 percent increase) and that the bending moment due to gust loading can be almost totally eliminated by a control system of about 10 to 20 percent span with reasonable control-surface rotations.

  20. Lucid dreams: their advantage and disadvantage in the frame of search activity concept.

    PubMed

    Rotenberg, Vadim S

    2015-01-01

    Search activity (SA) is the behavioral and mental activity that is oriented to changes of the environment or of the subject's view and approach to the environment according to personal needs without the definite probability forecast of the outcomes of such activity, but with a regular consideration of the outcomes in the process of active behavior. Dream's lucidity (the subject's realization that he/she is dreaming) protects dreamer from awakenings during emotionally disturbing or frustrating dreams, because lucid dreams allow subject to feel separated from the dream events that may cause a feeling of helplessness. Due to such a protection from awakenings that can bring subject back to the frustration in wakefulness, subject can turn in the further sleep to normal non-lucid dreams that are restoring subject's SA in the subsequent wakefulness (activity in the uncertain situation with the feedback between behavior and its outcome). It is the advantage of lucid dreams. Their disadvantage is that due to the separation from the dream events that are in lucid dreams accepted as rationalized dreams, not as real stories where the dreamer acts like in wakefulness, their ability to restore SA is decreased until they are not displaced by the normal non-lucid dreams accepted as real stories. PMID:26483727

  1. Lucid dreams: their advantage and disadvantage in the frame of search activity concept.

    PubMed

    Rotenberg, Vadim S

    2015-01-01

    Search activity (SA) is the behavioral and mental activity that is oriented to changes of the environment or of the subject's view and approach to the environment according to personal needs without the definite probability forecast of the outcomes of such activity, but with a regular consideration of the outcomes in the process of active behavior. Dream's lucidity (the subject's realization that he/she is dreaming) protects dreamer from awakenings during emotionally disturbing or frustrating dreams, because lucid dreams allow subject to feel separated from the dream events that may cause a feeling of helplessness. Due to such a protection from awakenings that can bring subject back to the frustration in wakefulness, subject can turn in the further sleep to normal non-lucid dreams that are restoring subject's SA in the subsequent wakefulness (activity in the uncertain situation with the feedback between behavior and its outcome). It is the advantage of lucid dreams. Their disadvantage is that due to the separation from the dream events that are in lucid dreams accepted as rationalized dreams, not as real stories where the dreamer acts like in wakefulness, their ability to restore SA is decreased until they are not displaced by the normal non-lucid dreams accepted as real stories.

  2. Lucid dreams: their advantage and disadvantage in the frame of search activity concept

    PubMed Central

    Rotenberg, Vadim S.

    2015-01-01

    Search activity (SA) is the behavioral and mental activity that is oriented to changes of the environment or of the subject's view and approach to the environment according to personal needs without the definite probability forecast of the outcomes of such activity, but with a regular consideration of the outcomes in the process of active behavior. Dream's lucidity (the subject's realization that he/she is dreaming) protects dreamer from awakenings during emotionally disturbing or frustrating dreams, because lucid dreams allow subject to feel separated from the dream events that may cause a feeling of helplessness. Due to such a protection from awakenings that can bring subject back to the frustration in wakefulness, subject can turn in the further sleep to normal non-lucid dreams that are restoring subject's SA in the subsequent wakefulness (activity in the uncertain situation with the feedback between behavior and its outcome). It is the advantage of lucid dreams. Their disadvantage is that due to the separation from the dream events that are in lucid dreams accepted as rationalized dreams, not as real stories where the dreamer acts like in wakefulness, their ability to restore SA is decreased until they are not displaced by the normal non-lucid dreams accepted as real stories. PMID:26483727

  3. Linking environmental variability and fish performance: integration through the concept of scope for activity.

    PubMed

    Claireaux, Guy; Lefrançois, Christel

    2007-11-29

    Investigating the biological mechanisms linking environmental variability to fish production systems requires the disentangling of the interactions between habitat, environmental adaptation and fitness. Since the number of environmental variables and regulatory processes is large, straightening out the environmental influences on fish performance is intractable unless the mechanistic analysis of the 'fish-milieu' system is preceded by an understanding of the properties of that system. While revisiting the key points in our currently poorly integrated understanding of fish ecophysiology, we have highlighted the explanatory potential contained within Fry's (Fry 1947 Univ. Toronto Stud. Biol. Ser. 55, 1-62) concept of metabolic scope and categorization of environmental factors. These two notions constitute a pair of powerful tools for conducting an external (at the emerging property level) analysis of the environmental influences on fish, as well as an internal (mechanistic) examination of the behavioural, morphological and physiological processes involved. Using examples from our own and others work, we have tried to demonstrate that Fry's framework represents a valuable conceptual basis leading to a broad range of testable ecophysiological hypotheses.

  4. A turn-key Concept for active cancellation of Global Positioning System L3 Signal

    NASA Astrophysics Data System (ADS)

    Nigra, Lou; Lewis, B. M.; Edgar, C. E.; Perillat, P.; Quintero, L.; Stanimirovic, S.; Gallagher, J. S., III

    2011-01-01

    We present a concept, developed at the National Astronomy and Ionosphere Center (NAIC) at Arecibo, Puerto Rico, for suppression of Global Positioning System (GPS) signals in the 305 m dish radio receiver path prior to backend processing. The subsystem does not require an auxiliary antenna and is intended for easy integration with radio telescope systems with a goal of being a turnkey addition to virtually any facility. We have focused on detection and cancellation of the GPS L3 signal at 1381.05 MHz which, during periodic test modes and particularly during system-wide tests, interfere with observations of objects in a range of redshifts that includes the Coma supercluster, for example. The signal can dynamically change modulation modes and our scheme has demonstrated, through simulations using actual sampled telescope data, the ability to acquire and track these signals as well as detect the mode changes in order to apply cancellation or blanking, as appropriate. The subsystem can also be adapted to GPS L1 (1575.42 MHz), L2C (1227.6 MHz), and others. A follow-up is underway to develop a prototype to deploy and evaluate at NAIC.

  5. An exposure:activity profiling method for interpreting high-throughput screening data for estrogenic activity--proof of concept.

    PubMed

    Becker, Richard A; Friedman, Katie Paul; Simon, Ted W; Marty, M Sue; Patlewicz, Grace; Rowlands, J Craig

    2015-04-01

    Rapid high throughput in vitro screening (HTS) assays are now available for characterizing dose-responses in assays that have been selected for their sensitivity in detecting estrogen-related endpoints. For example, EPA's ToxCast™ program recently released endocrine assay results for more than 1800 substances and the interagency Tox21 consortium is in the process of releasing data for approximately 10,000 chemicals. But such activity measurements alone fall short for the purposes of priority setting or screening because the relevant exposure context is not considered. Here, we extend the method of exposure:activity profiling by calculating the exposure:activity ratios (EARs) using human exposure estimates and AC50 values for a range of chemicals tested in a suite of seven estrogenic assays in ToxCast™ and Tox21. To provide additional context, relative estrogenic exposure:activity quotients (REEAQ) were derived by comparing chemical-specific EARs to the EAR of the ubiquitous dietary phytoestrogen, genistein (GEN). Although the activity of a substance in HTS-endocrine assays is not a measure of health hazard or risk, understanding how such a dose compares to human exposures provides a valuable additional metric that can be used in decision-making; substances with small EARs and REEAQs would indicate low priority for further endocrine screening or testing. PMID:25656492

  6. The use of active learning strategies in the instruction of Reactor Physics concepts

    SciTech Connect

    Robinson, Michael A.

    2000-01-01

    Each of the Active Learning strategies employed to teach Reactor Physics material has been or promises to be instructionally successful. The Cooperative Group strategy has demonstrated a statistically significant increase in student performance on the unit exam in teaching conceptually difficult, transport and diffusion theory material. However, this result was achieved at the expense of a modest increase in class time. The Tutorial CBI programs have enabled learning equally as well as classroom lectures without the direct intervention of an instructor. Thus, the Tutorials have been successful as homework assignments, releasing classroom time for other instruction. However, the time required for development of these tools was large, on the order of two hundred hours per hour of instruction. The initial introduction of the Case-Based strategy was roughly as effective as the traditional classroom instruction. Case-Based learning could well, after important modifications, perform better than traditional instruction. A larger percentage of the students prefer active learning strategies than prefer traditional lecture presentations. Student preferences for the active strategies were particularly strong when they believed that the strategies helped them learn the material better than they would have by using a lecture format. In some cases, students also preferred the active strategies because they were different from traditional instruction, a change of pace. Some students preferred lectures to CBI instruction, primarily because the CBI did not afford them the opportunity to question the instructor during the presentation.

  7. Toward Enriched Conceptions of Work Learning: Participation, Expansion, and Translation among Individuals with/in Activity

    ERIC Educational Resources Information Center

    Fenwick, Tara

    2006-01-01

    This article argues that understandings of work learning within human resource development (HRD) theory can be fruitfully enriched by more fully incorporating practice-based perspectives. Three contemporary theories that analyze learning as a relation of individuals with and/or in activity are discussed: the participational perspective of situated…

  8. An Active Learning Approach to Teach Advanced Multi-Predictor Modeling Concepts to Clinicians

    ERIC Educational Resources Information Center

    Samsa, Gregory P.; Thomas, Laine; Lee, Linda S.; Neal, Edward M.

    2012-01-01

    Clinicians have characteristics--high scientific maturity, low tolerance for symbol manipulation and programming, limited time outside of class--that limit the effectiveness of traditional methods for teaching multi-predictor modeling. We describe an active-learning based approach that shows particular promise for accommodating these…

  9. Test Rig for Evaluating Active Turbine Blade Tip Clearance Control Concepts

    NASA Technical Reports Server (NTRS)

    Lattime, Scott B.; Steinetz, Bruce M.; Robbie, Malcolm G.

    2003-01-01

    Improved blade tip sealing in the high pressure compressor and high pressure turbine can provide dramatic improvements in specific fuel consumption, time-on-wing, compressor stall margin and engine efficiency as well as increased payload and mission range capabilities of both military and commercial gas turbine engines. The preliminary design of a mechanically actuated active clearance control (ACC) system for turbine blade tip clearance management is presented along with the design of a bench top test rig in which the system is to be evaluated. The ACC system utilizes mechanically actuated seal carrier segments and clearance measurement feedback to provide fast and precise active clearance control throughout engine operation. The purpose of this active clearance control system is to improve upon current case cooling methods. These systems have relatively slow response and do not use clearance measurement, thereby forcing cold build clearances to set the minimum clearances at extreme operating conditions (e.g., takeoff, re-burst) and not allowing cruise clearances to be minimized due to the possibility of throttle transients (e.g., step change in altitude). The active turbine blade tip clearance control system design presented herein will be evaluated to ensure that proper response and positional accuracy is achievable under simulated high-pressure turbine conditions. The test rig will simulate proper seal carrier pressure and temperature loading as well as the magnitudes and rates of blade tip clearance changes of an actual gas turbine engine. The results of these evaluations will be presented in future works.

  10. Making Physics Fun: Key Concepts, Classroom Activities, and Everyday Examples, Grades K-8

    ERIC Educational Resources Information Center

    Prigo, Robert

    2007-01-01

    Teaching physical science in the elementary and middle grades can be challenging for busy teachers faced with growing science demands and limited classroom resources. Robert Prigo provides fun and engaging activities using safe, available materials that educators can easily incorporate into lesson plans. Extensive examples, sample inquiry…

  11. Analyzing Science Activities in Force and Motion Concepts: A Design of an Immersion Unit

    ERIC Educational Resources Information Center

    Ayar, Mehmet C.; Aydeniz, Mehmet; Yalvac, Bugrahan

    2015-01-01

    In this paper, we analyze the science activities offered at 7th grade in the Turkish science and technology curriculum along with addressing the curriculum's original intent. We refer to several science education researchers' ideas, including Chinn & Malhotra's (Science Education, 86:175--218, 2002) theoretical framework and…

  12. [Regulation of cell activity by the extracellular matrix: the concept of matrikines].

    PubMed

    Maquart, F X; Siméon, A; Pasco, S; Monboisse, J C

    1999-01-01

    The activity of connective tissue cells is modulated by a number of factors present in their environment. In addition to the soluble factors such as hormones, cytokines or growth factors, cells also receive signals from the surrounding extracellular matrix (ECM) macromolecules. Moreover, they may degrade the ECM proteins and liberate peptides which may by themselves constitute new signals for the surrounding cells. Therefore, an actual regulation loop exists in connective tissue, constituted by peptides generated by ECM degradation and connective tissue cells. The term of "matrikine" has been proposed to designate such ECM-derived peptides able to regulate cell activity. In this review, we summarize some data obtained in our laboratory with two different matrikines: the tripeptide glycyl-histidyl-lysine (GHK) and the heptapeptide cysteinyl-asparaginyl-tyrosyl-tyrosyl-seryl-asparaginyl-serine (CNYYSNS). GHK is a potent activator of ECM synthesis and remodeling, whereas CNYYSNS is able to inhibit polymorphonuclear leukocytes activation and decrease the invasive capacities of cancer cells. PMID:10689625

  13. Energy Use and the Environment. Concepts & Activities for the Classroom: Secondary Social Studies Module.

    ERIC Educational Resources Information Center

    Hawaii State Dept. of Education, Honolulu. Office of Instructional Services.

    As part of a comprehensive, interdisciplinary environmental education program for elementary and secondary education in Hawaii, this teaching guide provides a variety of energy education activities for secondary social studies. An extensive introduction outlines the total program and how it fits into the general education program. It explains how…

  14. Active Learning and Threshold Concepts in Multiple Testing That Can Further Develop Student Critical Statistical Thinking

    ERIC Educational Resources Information Center

    White, Desley

    2015-01-01

    Two practical activities are described, which aim to support critical thinking about statistics as they concern multiple outcomes testing. Formulae are presented in Microsoft Excel spreadsheets, which are used to calculate the inflation of error associated with the quantity of tests performed. This is followed by a decision-making exercise, where…

  15. Using Concept Mapping to Identify Action Steps for Physical Activity Promotion in Cancer Treatment

    ERIC Educational Resources Information Center

    Fitzpatrick, Sean Joseph; Zizzi, Sam J.

    2014-01-01

    Background: The benefits of exercise during and after cancer treatment represent research areas that have received increased attention throughout the past 2 decades. Numerous benefits have been observed for cancer survivors who are physically active, yet oncologists have been slow to incorporate exercise counseling into practice. Purpose: The…

  16. Student Engagement with Artefacts and Scientific Ideas in a Laboratory and a Concept-Mapping Activity

    ERIC Educational Resources Information Center

    Hamza, Karim Mikael; Wickman, Per-Olof

    2013-01-01

    The purpose of this study is to use a comparative approach to scrutinize the common assumption that certain school science activities are theoretical and therefore particularly suited for engaging students with scientific ideas, whereas others are practical and, thus, not equally conducive to engagement with scientific ideas. We compared two…

  17. Using a Concept Mapping Tool with a Photograph Association Technique (CoMPAT) to Elicit Children's Ideas about Microbial Activity

    ERIC Educational Resources Information Center

    Byrne, Jenny; Grace, Marcus

    2010-01-01

    Concept mapping is a technique used to provide a visual representation of an individual's ideas about a concept or set of related concepts. This paper describes a concept mapping tool using a photograph association technique (CoMPAT) that is considered to be a novel way of eliciting children's ideas. What children at 11 years of age know about…

  18. A new concept for an active element for the large cosmic ray calorimeter ani

    NASA Astrophysics Data System (ADS)

    Lorenz, E.; Borngrebe, S.; Chilingarian, A.; Ferenc, D.; Mirzoyan, R.; Schwarz, R.

    . For the ANI calorimeter (40 x 40 m¡ , 6 concrete absorber layers of 1 m thickness each) at mount Aragatz, Armenia, a cheap and efficient active detector element is needed. One solution is to use long, square tubes (20 x 0.3 x 0.3 m¢ ) filled with wavelength shifter dye doped water. Two PMTs at the ends serve to read out the Cherenkov light generated by fast charged particles. For the crucial light transport along the tubes the walls are lined by a new superreflector foil from 3M (dielectric reflector foil with R £ 98%). From test measurements, a light attenuation of a factor 10-15 over the full length is expected. Due to the high active material fraction of the calorimeter of nearly 15% a good energy and spatial resolution is expected. Prototype results will be presented.

  19. Catalytic enantioselective OFF ↔ ON activation processes initiated by hydrogen transfer: concepts and challenges.

    PubMed

    Quintard, Adrien; Rodriguez, Jean

    2016-08-18

    Hydrogen transfer initiated processes are eco-compatible transformations allowing the reversible OFF ↔ ON activation of otherwise unreactive substrates. The minimization of stoichiometric waste as well as the unique activation modes provided by these transformations make them key players for a greener future for organic synthesis. Long limited to catalytic reactions that form racemic products, considerable progress on the development of strategies for controlling diastereo- and enantioselectivity has been made in the last decade. The aim of this review is to present the different strategies that enable enantioselective transformations of this type and to highlight how they can be used to construct key synthetic building blocks in fewer operations with less waste generation. PMID:27381644

  20. Selected advanced aerodynamics and active controls technology concepts development on a derivative B-747 aircraft

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Analytical design and wind tunnel test evaluations covering the feasibility of applying wing tip extensions, winglets, and active control wing had alleviation to the model B747 are described. Aerodynamic improvement offered by wing tip extension and winglet individually, and the combined aerodynamic and weight improvements when wing load alleviation is combined with the tip extension or the winglet are evaluated. Results are presented in the form of incremental effects on weight mission range, fuel usage, cost, and airline operating economics.

  1. Test Rig for Active Turbine Blade Tip Clearance Control Concepts: An Update

    NASA Technical Reports Server (NTRS)

    Taylor, Shawn; Steinetz, Bruce; Oswald, Jay; DeCastro, Jonathan; Melcher, Kevin

    2006-01-01

    The objective is to develop and demonstrate a fast-acting active clearance control system to improve turbine engine performance, reduce emissions, and increase service life. System studies have shown the benefits of reducing blade tip clearances in modern turbine engines. Minimizing blade tip clearances throughout the engine will contribute materially to meeting NASA's Ultra-Efficient Engine Technology (UEET) turbine engine project goals. NASA GRC is examining two candidate approaches including rub-avoidance and regeneration which are explained in subsequent slides.

  2. Perception and conception: temporal lobe activity during complex discriminations of familiar and novel faces and objects.

    PubMed

    Barense, Morgan D; Henson, Richard N A; Graham, Kim S

    2011-10-01

    Recent studies indicate that medial-temporal lobe (MTL) damage, either from focal lesions or neurodegenerative disease (e.g., semantic dementia), impairs perception as well as long-term declarative memory. Notably, however, these two patient groups show different performance for meaningful versus unfamiliar stimuli. In amnesics with nonprogressive MTL lesions, the use of meaningful stimuli, compared with unfamiliar items, boosted discrimination performance. In semantic dementia, a condition characterized by progressive deterioration of conceptual knowledge in the context of anterolateral temporal lobe damage, performance for meaningful stimuli was equivalent to that for unfamiliar items. To further investigate these findings, we scanned healthy volunteers while they performed odd-one-out discriminations involving familiar (i.e., meaningful/famous) and unfamiliar (i.e., novel) objects and faces and a baseline task of size oddity. Outside the scanner, volunteers' recognition memory was assessed. We found above baseline activity in the perirhinal cortex and hippocampus for all object and face discriminations and above baseline activity in the temporal pole for all face discriminations. The comparison of meaningful, relative to novel, faces and objects, revealed increased activity in the perirhinal cortex and hippocampus. In the temporal pole, we also found activity related to meaningfulness for faces but not for objects. Importantly, these meaningfulness effects were evident even for discriminations that were not subsequently well remembered, suggesting that the difference between meaningful and novel stimuli reflects perceptual or conceptual processes rather than solely incidental encoding into long-term memory. The results provide further evidence that the MTL is recruited during complex perceptual discrimination and additionally suggest that these structures are recruited in semantic processing of objects and faces.

  3. Past, present, and future concepts in large river ecology: How rivers function and how human activities influence river processes

    SciTech Connect

    Johnson, B.L.; Richardson, W.B.; Naimo, T.J.

    1995-03-01

    This article reviews the current concepts on how flowing water, or lotic, systems function and suggest ways to expand these concepts to increase understanding of large river systems. Topics covered include the following: past and present approaches to physical and biological concepts of stream organization; the river-continuum concept; the flood-pulse concept; deficiencies of the current hypotheses (linear versis hierachical, physical verses biological control, equilibrium versus disequilibrium); future directions for large river research. 63 refs., 4 figs.

  4. Factors affecting expression of estrus measured by activity monitors and conception risk of lactating dairy cows.

    PubMed

    Madureira, A M L; Silper, B F; Burnett, T A; Polsky, L; Cruppe, L H; Veira, D M; Vasconcelos, J L M; Cerri, R L A

    2015-10-01

    The objective of this study was to determine risk-factors affecting increase in physical activity during estrus and pregnancy per artificial insemination (P/AI) in lactating dairy cows. Cows were monitored continuously by 2 automated activity monitors [a collar-mounted accelerometer (HT; Heatime, SCR Engineers, Netanya, Israel) and a leg-mounted pedometer (BO; Boumatic Heat-seeker-TX, Boumatic Dairy Equipment, Madison, WI)]. When an increase in activity was detected, body condition score (BCS) and blood samples were collected, ovaries were scanned by ultrasonography, and, if the cow was eligible for breeding, artificial insemination was performed. Milk production and health-related data were recorded throughout the experimental period. Pregnancy diagnosis was performed at 42 ± 7 d of gestation. Data were analyzed using Pearson correlation, ANOVA, and logistic regression. A total of 1,099 true events of estrus from 318 lactating Holstein cows were recorded, averaging 3.46 ± 1.1 events per cow. Positive predictive value for estrus episodes detected by the HT and BO systems were 89.6 and 85.5%, respectively. Mean peak activity at estrus (PA) recorded by the HT system was 71.6 ± 20.7 index-value, and 334.3 ± 155.7% relative increase by the BO system. Compared with primiparous, multiparous cows expressed estrus with lower PA (69.3 ± 0.8 vs. 75.9 ± 1.1 index for HT; 323.9 ± 6.0 vs. 354.8 ± 8.48% for BO) and shorter duration (DU; 10.7 ± 0.2 vs. 12.0 ± 0.3 h); DU was measured by HT only. Lower BCS was associated with decreased PA measured by both systems, estrus DU, and P/AI. Peak activity was weakly correlated with milk production on the day of artificial insemination (r = -0.20); however, when categorized into quartiles, the highest-yield cows had lower PA and DU. Follicle diameter was not correlated with PA or DU, but cows with greater concentrations of estradiol had higher PA. Cows with greater PA in both systems had greater P/AI than those with lower PA (36

  5. Factors affecting expression of estrus measured by activity monitors and conception risk of lactating dairy cows.

    PubMed

    Madureira, A M L; Silper, B F; Burnett, T A; Polsky, L; Cruppe, L H; Veira, D M; Vasconcelos, J L M; Cerri, R L A

    2015-10-01

    The objective of this study was to determine risk-factors affecting increase in physical activity during estrus and pregnancy per artificial insemination (P/AI) in lactating dairy cows. Cows were monitored continuously by 2 automated activity monitors [a collar-mounted accelerometer (HT; Heatime, SCR Engineers, Netanya, Israel) and a leg-mounted pedometer (BO; Boumatic Heat-seeker-TX, Boumatic Dairy Equipment, Madison, WI)]. When an increase in activity was detected, body condition score (BCS) and blood samples were collected, ovaries were scanned by ultrasonography, and, if the cow was eligible for breeding, artificial insemination was performed. Milk production and health-related data were recorded throughout the experimental period. Pregnancy diagnosis was performed at 42 ± 7 d of gestation. Data were analyzed using Pearson correlation, ANOVA, and logistic regression. A total of 1,099 true events of estrus from 318 lactating Holstein cows were recorded, averaging 3.46 ± 1.1 events per cow. Positive predictive value for estrus episodes detected by the HT and BO systems were 89.6 and 85.5%, respectively. Mean peak activity at estrus (PA) recorded by the HT system was 71.6 ± 20.7 index-value, and 334.3 ± 155.7% relative increase by the BO system. Compared with primiparous, multiparous cows expressed estrus with lower PA (69.3 ± 0.8 vs. 75.9 ± 1.1 index for HT; 323.9 ± 6.0 vs. 354.8 ± 8.48% for BO) and shorter duration (DU; 10.7 ± 0.2 vs. 12.0 ± 0.3 h); DU was measured by HT only. Lower BCS was associated with decreased PA measured by both systems, estrus DU, and P/AI. Peak activity was weakly correlated with milk production on the day of artificial insemination (r = -0.20); however, when categorized into quartiles, the highest-yield cows had lower PA and DU. Follicle diameter was not correlated with PA or DU, but cows with greater concentrations of estradiol had higher PA. Cows with greater PA in both systems had greater P/AI than those with lower PA (36

  6. Spatial conception of activities: a socio-cognitive perspective for simulating work practices.

    PubMed

    Clancey, William J

    2015-09-01

    People conceive their everyday affairs (their practices) as social actors in activities, in which they perceive, infer, move, manipulate objects, and communicate in some physical setting (e.g., going to the grocery to buy dinner). These behaviors are conceptually choreographed in an ongoing, usually tacit understanding of "what I'm doing now," encapsulating roles ("who I'm being now"), norms ("what I should be doing"; "how I should be dressed/talking/sitting"), and progress appraisals ("how well I'm doing"). Activity motives and modalities vary widely (e.g., waiting in line, listening to music, sleeping), all of which require time and occur in particular settings. Brahms is a multi-agent work systems design tool for modeling and simulating activities, used extensively to design aerospace work systems. For example, the Generalized Überlingen Model (Brahms-GÜM) simulates air transportation practices, focusing on how pilots and air traffic controllers interact with automated systems in safety-critical, time-pressured encounters. Spatial cognition is pervasive: scanning displays of multiple workstations; coordinating airspaces and flight paths; and prioritizing and timing interventions to maintain aircraft separations. Brahms-GÜM demonstrates how events may become unpredictable when aspects of the work system are missing or malfunctioning, making a routinely complicated system into one that is cognitively complex and becomes out of control. Normally, asynchronous processes become coupled in space and time, leading to difficulty comprehending the situation ("what is happening now") as a familiar multi-modal flow of events. Such examples illustrate the dynamics of spatial cognition inherent in our conceptually situated experience--our consciousness--of who we are and what we are doing. PMID:26271309

  7. Spatial conception of activities: a socio-cognitive perspective for simulating work practices.

    PubMed

    Clancey, William J

    2015-09-01

    People conceive their everyday affairs (their practices) as social actors in activities, in which they perceive, infer, move, manipulate objects, and communicate in some physical setting (e.g., going to the grocery to buy dinner). These behaviors are conceptually choreographed in an ongoing, usually tacit understanding of "what I'm doing now," encapsulating roles ("who I'm being now"), norms ("what I should be doing"; "how I should be dressed/talking/sitting"), and progress appraisals ("how well I'm doing"). Activity motives and modalities vary widely (e.g., waiting in line, listening to music, sleeping), all of which require time and occur in particular settings. Brahms is a multi-agent work systems design tool for modeling and simulating activities, used extensively to design aerospace work systems. For example, the Generalized Überlingen Model (Brahms-GÜM) simulates air transportation practices, focusing on how pilots and air traffic controllers interact with automated systems in safety-critical, time-pressured encounters. Spatial cognition is pervasive: scanning displays of multiple workstations; coordinating airspaces and flight paths; and prioritizing and timing interventions to maintain aircraft separations. Brahms-GÜM demonstrates how events may become unpredictable when aspects of the work system are missing or malfunctioning, making a routinely complicated system into one that is cognitively complex and becomes out of control. Normally, asynchronous processes become coupled in space and time, leading to difficulty comprehending the situation ("what is happening now") as a familiar multi-modal flow of events. Such examples illustrate the dynamics of spatial cognition inherent in our conceptually situated experience--our consciousness--of who we are and what we are doing.

  8. Recent sounding rocket highlights and a concept for melding sounding rocket and space shuttle activities

    NASA Technical Reports Server (NTRS)

    Lane, J. H.; Mayo, E. E.

    1980-01-01

    Highlights include launching guided vehicles into the African Solar Eclipse, initiation of development of a Three-Stage Black Brant to explore the dayside polar cusp, large payload Aries Flights at White Sands Missile Range, and an active program with the Orion vehicle family using surplus motors. Sounding rocket philosophy and experience is being applied to the shuttle in a Get Away Special and Experiments of Opportunity Payloads Programs. In addition, an orbit selection and targeting software system to support shuttle pallet mounted experiments is under development.

  9. Active penetration of Trypanosoma cruzi into host cells: historical considerations and current concepts

    PubMed Central

    de Souza, Wanderley; de Carvalho, Tecia M. Ulisses

    2013-01-01

    In the present short review, we analyze past experiments that addressed the interactions of intracellular pathogenic protozoa (Trypanosoma cruzi, Toxoplasma gondii, and Plasmodium) with host cells and the initial use of the term active penetration to indicate that a protozoan “crossed the host cell membrane, penetrating into the cytoplasm.” However, the subsequent use of transmission electron microscopy showed that, for all of the protozoans and cell types examined, endocytosis, classically defined as involving the formation of a membrane-bound vacuole, took place during the interaction process. As a consequence, the recently penetrated parasites are always within a vacuole, designated the parasitophorous vacuole (PV). PMID:23355838

  10. Active penetration of Trypanosoma cruzi into host cells: historical considerations and current concepts.

    PubMed

    de Souza, Wanderley; de Carvalho, Tecia M Ulisses

    2013-01-01

    In the present short review, we analyze past experiments that addressed the interactions of intracellular pathogenic protozoa (Trypanosoma cruzi, Toxoplasma gondii, and Plasmodium) with host cells and the initial use of the term active penetration to indicate that a protozoan "crossed the host cell membrane, penetrating into the cytoplasm." However, the subsequent use of transmission electron microscopy showed that, for all of the protozoans and cell types examined, endocytosis, classically defined as involving the formation of a membrane-bound vacuole, took place during the interaction process. As a consequence, the recently penetrated parasites are always within a vacuole, designated the parasitophorous vacuole (PV). PMID:23355838

  11. A Space Weather mission concept: Observatories of the Solar Corona and Active Regions (OSCAR)

    NASA Astrophysics Data System (ADS)

    Strugarek, Antoine; Janitzek, Nils; Lee, Arrow; Löschl, Philipp; Seifert, Bernhard; Hoilijoki, Sanni; Kraaikamp, Emil; Isha Mrigakshi, Alankrita; Philippe, Thomas; Spina, Sheila; Bröse, Malte; Massahi, Sonny; O'Halloran, Liam; Pereira Blanco, Victor; Stausland, Christoffer; Escoubet, Philippe; Kargl, Günter

    2015-02-01

    Coronal Mass Ejections (CMEs) and Corotating Interaction Regions (CIRs) are major sources of magnetic storms on Earth and are therefore considered to be the most dangerous space weather events. The Observatories of Solar Corona and Active Regions (OSCAR) mission is designed to identify the 3D structure of coronal loops and to study the trigger mechanisms of CMEs in solar Active Regions (ARs) as well as their evolution and propagation processes in the inner heliosphere. It also aims to provide monitoring and forecasting of geo-effective CMEs and CIRs. OSCAR would contribute to significant advancements in the field of solar physics, improvements of the current CME prediction models, and provide data for reliable space weather forecasting. These objectives are achieved by utilising two spacecraft with identical instrumentation, located at a heliocentric orbital distance of 1 AU from the Sun. The spacecraft will be separated by an angle of 68° to provide optimum stereoscopic view of the solar corona. We study the feasibility of such a mission and propose a preliminary design for OSCAR.

  12. A new method for spatially selective, non-invasive activation of neurons: concept and computer simulation.

    PubMed

    Konings, Maurits K

    2007-01-01

    Currently available non-invasive neurostimulation devices, using skin electrodes or externally applied magnetic coils, are not capable of producing a local stimulation maximum deep inside a homogeneous conductor, because of a fundamental limitation inherent to the Laplace equation. In this paper, a new neurostimulation method (the DeepFocus method) is presented, which avoids this limitation by using an indirect method of producing electric currents inside tissues: First, cylinder-shaped ferromagnetic rotating disks of non-permanent magnetic material are placed near the skin and magnetized by a non-rotating magnetic coil. Each of the disks rotates at high speed around its own axis of symmetry, thus producing a purely electric Lorentz force field having a non-zero divergence outside the disk, and therefore giving rise to charge accumulations inside the tissues. Subsequently, the magnetic field is switched off suddenly, causing a re-distribution of charge, and hence short-lived electrical currents, which can be used to activate neurons. Two magnet configurations are presented in this paper, and analyzed by computer simulation, showing that the DeepFocus method produces a maximum current density (the 'focus') deep inside the conducting body. The field strength thus created in the focus (7.9 V/m) is strong enough to activate thick myelinated fibers, but can be kept below the threshold for C-fibers, which makes the new method a possible tool for pain mitigation by targeted neurostimulation. PMID:17186214

  13. Zinc polycarboxylate dental cement for the controlled release of an active organic substance: proof of concept.

    PubMed

    Ali, Mohammad Naseem; Edwards, Mark; Nicholson, John W

    2010-04-01

    The potential of employing zinc polycarboxylate dental cement as a controlled release material has been studied. Benzalkonium chloride was used as the active ingredient, and incorporated at concentrations of 1, 2 and 3% by mass within the cement. At these levels, there was no observable effect on the speed of setting. Release was followed using an ion-selective electrode to determine changes in chloride ion concentration with time. This technique showed that the additive was released when the cured cement was placed in water, with release occurring by a diffusion mechanism for the first 3 h, but continuing beyond that for up to 1 week. Diffusion coefficients were in the range 5.62 x 10(-6) cm(2) s(-1) (for 1% concentration) to 10.90 x 10(-6) cm(2) s(-1) (for 3% concentration). Up to 3% of the total loading of benzalkonium chloride was released from the zinc polycarboxylate after a week, which is similar to that found in previous studies with glass-ionomer cement. It is concluded that zinc polycarboxylate cement is capable of acting as a useful material for the controlled release of active organic compounds.

  14. Conception et exploitation d'une structure active pour une aile laminaire adaptative experimentale

    NASA Astrophysics Data System (ADS)

    Coutu, Daniel

    This doctoral research contributed to the success of the project CRIAQ 7.1, demonstrating the capability of a morphing laminar wing to reduce fuel consumption. Respectively, this thesis shows the design of the experimental wing and its operation in a subsonic wind tunnel (Mach numbers of 0.2 to 0.3 with angles of attack between -1 and 2°). First of all, the morphing wing is formed of a composite laminate linked to an actuation system to build an active structure capable of modifying the wing upper surface geometry. The design was performed using a new developed methodology to solve aero-structural problems. Using ANSYS software, the finite elements method was applied to model the different possible active structure configurations Aerodynamic loads applied over the active structure as well as targeted morphed geometries have been provided by the Ecole Polytechnique team. Next, laminar flow enhancements allowed by each active structure configuration we' re evaluated using the aerodynamic solver XFoil 6.96. A best trade-off between aerodynamic performance and energy needed for wing morphing was found using a multi-objective optimization technique. Among the retained stable configurations, a 4-ply composite laminated shell driven by 2 actuation lines was retained. Thereafter, the research effort focused on the exploitation of the morphing capabilities of the experimental wing over each given set of flow conditions. Therefore, once the prototype was built, the structural model was refined, calibrated and coupled with the aerodynamic solver to accurately predict the aero-structural behavior in the wind tunnel. Optimal morphing wing shapes were numerically calculated using a generalized pattern search algorithm and a local search routine to refine the solution. In the wind tunnel, this open-loop control approach allowed an average 25% laminar flow regime extension over the wing prototype upper surface. Consequently, an average 18.5% profile drag reduction was measured by

  15. Quantitative assessment of olfactory receptors activity in immobilized nanosomes: a novel concept for bioelectronic nose.

    PubMed

    Vidic, Jasmina Minic; Grosclaude, Jeanne; Persuy, Marie-Annick; Aioun, Josiane; Salesse, Roland; Pajot-Augy, Edith

    2006-08-01

    We describe how mammalian olfactory receptors (ORs) could be used as sensing elements of highly specific and sensitive bioelectronic noses. An OR and an appropriate G(alpha) protein were co-expressed in Saccharomyces cerevisiae cells from which membrane nanosomes were prepared, and immobilized on a sensor chip. By Surface Plasmon Resonance, we were able to quantitatively evaluate OR stimulation by an odorant, and G protein activation. We demonstrate that ORs in nanosomes discriminate between odorant ligands and unrelated odorants, as in whole cells. This assay also provides the possibility for quantitative assessment of the coupling efficiency of the OR with different G(alpha) subunits, without the interference of the cellular transduction pathway. Our findings will be useful to develop a new generation of electronic noses for detection and discrimination of volatile compounds, particularly amenable to micro- and nano-sensor formats.

  16. Development and flight evaluation of an augmented stability active controls concept with a small tail

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Parasite drag reduction evaluation is composed of wind tunnel tests with a standard L-1011 tail and two reduced area tail configurations. Trim drag reduction is evaluated by rebalancing the airplane for relaxed static stability. This is accomplished by pumping water to tanks in the forward and aft of the airplane to acheive desired center of gravity location. Also, the L-1011 is modified to incorporate term and advanced augmented systems. By using advanced wings and aircraft relaxed static stability significant fuel savings can be realized. An airplane's dynamic stability becomes more sensitive for decreased tail size, relaxed static stability, and advanced wing configurations. Active control pitch augmentation will be used to acheive the required handling qualities. Flight tests will be performed to evaluate the pitch augmentation systems. The effect of elevator downrig on stabilizer/elevator hinge moments will be measured. For control system analysis, the normal acceleration feedback and pitch rate feedback are analyzed.

  17. Concepts and techniques: Active electronics and computers in safety-critical accelerator operation

    SciTech Connect

    Frankel, R.S.

    1995-12-31

    The Relativistic Heavy Ion Collider (RHIC) under construction at Brookhaven National Laboratory, requires an extensive Access Control System to protect personnel from Radiation, Oxygen Deficiency and Electrical hazards. In addition, the complicated nature of operation of the Collider as part of a complex of other Accelerators necessitates the use of active electronic measurement circuitry to ensure compliance with established Operational Safety Limits. Solutions were devised which permit the use of modern computer and interconnections technology for Safety-Critical applications, while preserving and enhancing, tried and proven protection methods. In addition a set of Guidelines, regarding required performance for Accelerator Safety Systems and a Handbook of design criteria and rules were developed to assist future system designers and to provide a framework for internal review and regulation.

  18. Development of selected advanced aerodynamics and active control concepts for commercial transport aircraft

    NASA Technical Reports Server (NTRS)

    Taylor, A. B.

    1984-01-01

    Work done under the Energy Efficient Transport project in the field of advanced aerodynamics and active controls is summarized. The project task selections focused on the following: the investigation of long-duct nacelle shape variation on interference drag; the investigation of the adequacy of a simple control law for the elastic modes of a wing; the development of the aerodynamic technology at cruise and low speed of high-aspect-ratio supercritical wings of high performance; and the development of winglets for a second-generation jet transport. All the tasks involved analysis and substantial wind tunnel testing. The winglet program also included flight evaluation. It is considered that the technology base has been built for the application of high-aspect-ratio supercritical wings and for the use of winglets on second-generation transports.

  19. Characterizing Natural Gas Hydrates in the Deep Water Gulf of Mexico: Applications for Safe Exploration and Production Activities

    SciTech Connect

    Bent, Jimmy

    2014-05-31

    In 2000 Chevron began a project to learn how to characterize the natural gas hydrate deposits in the deep water portion of the Gulf of Mexico (GOM). Chevron is an active explorer and operator in the Gulf of Mexico and is aware that natural gas hydrates need to be understood to operate safely in deep water. In August 2000 Chevron worked closely with the National Energy Technology Laboratory (NETL) of the United States Department of Energy (DOE) and held a workshop in Houston, Texas to define issues concerning the characterization of natural gas hydrate deposits. Specifically, the workshop was meant to clearly show where research, the development of new technologies, and new information sources would be of benefit to the DOE and to the oil and gas industry in defining issues and solving gas hydrate problems in deep water.

  20. I 5683 you: dialing phone numbers on cell phones activates key-concordant concepts.

    PubMed

    Topolinski, Sascha

    2011-03-01

    When people perform actions, effects associated with the actions are activated mentally, even if those effects are not apparent. This study tested whether sequences of simulations of virtual action effects can be integrated into a meaning of their own. Cell phones were used to test this hypothesis because pressing a key on a phone is habitually associated with both digits (dialing numbers) and letters (typing text messages). In Experiment 1, dialing digit sequences induced the meaning of words that share the same key sequence (e.g., 5683, LOVE). This occurred even though the letters were not labeled on the keypad, and participants were not aware of the digit-letter correspondences. In Experiment 2, subjects preferred dialing numbers implying positive words (e.g., 37326, DREAM) over dialing numbers implying negative words (e.g., 75463, SLIME). In Experiment 3, subjects preferred companies with phone numbers implying a company-related word (e.g., LOVE for a dating agency, CORPSE for a mortician) compared with companies with phone numbers implying a company-unrelated word. PMID:21270449

  1. I 5683 you: dialing phone numbers on cell phones activates key-concordant concepts.

    PubMed

    Topolinski, Sascha

    2011-03-01

    When people perform actions, effects associated with the actions are activated mentally, even if those effects are not apparent. This study tested whether sequences of simulations of virtual action effects can be integrated into a meaning of their own. Cell phones were used to test this hypothesis because pressing a key on a phone is habitually associated with both digits (dialing numbers) and letters (typing text messages). In Experiment 1, dialing digit sequences induced the meaning of words that share the same key sequence (e.g., 5683, LOVE). This occurred even though the letters were not labeled on the keypad, and participants were not aware of the digit-letter correspondences. In Experiment 2, subjects preferred dialing numbers implying positive words (e.g., 37326, DREAM) over dialing numbers implying negative words (e.g., 75463, SLIME). In Experiment 3, subjects preferred companies with phone numbers implying a company-related word (e.g., LOVE for a dating agency, CORPSE for a mortician) compared with companies with phone numbers implying a company-unrelated word.

  2. Development and flight evaluation of an augmented stability active controls concept: Executive summary

    NASA Technical Reports Server (NTRS)

    Guinn, W. A.

    1982-01-01

    A pitch active control system (PACS) was developed and flight tested on a wide body jet transport (L-1011) with a flying horizontal stabilizer. Two dual channel digital computers and the associated software provide command signals to a dual channel series servo which controls the stabilizer power actuators. Input sensor signals to the computer are pitch rate, column trim position, and dynamic pressure. Control laws are given for the PACS and the system architecture is defined. Discussions are given regarding piloted flight simulation and vehicle system simulation and vehicle system simulation tests that are performed to verify control laws and system operation prior to installation on the aircraft. Modifications to the basic aircraft included installation of the PACS, addition of a c.g. management system to provide a c.g. range from 25 to 39% mac, and downrigging of the geared elevator to provide the required nose down control authority for aft c.g. flight test conditions. Three pilots used the Cooper-Harper Rating Scale to judge flying qualities of the aircraft with PACS on and off. The handling qualities with the c.g. at 39% mac (41% stability margin) and PACS operating were judged to be as good as the handling qualities with the c.g. at 25% mac (+15% stability margin) and PACS off.

  3. Combining Droop Curve Concepts with Control Systems for Wind Turbine Active Power Control: Preprint

    SciTech Connect

    Buckspan, A.; Aho, J.; Pao, L.; Fleming, P.; Jeong, Y.

    2012-06-01

    Wind energy is becoming a larger portion of the global energy portfolio and wind penetration has increased dramatically in certain regions of the world. This increasing wind penetration has driven the need for wind turbines to provide active power control (APC) services to the local utility grid, as wind turbines do not intrinsically provide frequency regulation services that are common with traditional generators. It is common for large scale wind turbines to be decoupled from the utility grid via power electronics, which allows the turbine to synthesize APC commands via control of the generator torque and blade pitch commands. Consequently, the APC services provided by a wind turbine can be more flexible than those provided by conventional generators. This paper focuses on the development and implementation of both static and dynamic droop curves to measure grid frequency and output delta power reference signals to a novel power set point tracking control system. The combined droop curve and power tracking controller is simulated and comparisons are made between simulations using various droop curve parameters and stochastic wind conditions. The tradeoffs involved with aggressive response to frequency events are analyzed. At the turbine level, simulations are performed to analyze induced structural loads. At the grid level, simulations test a wind plant's response to a dip in grid frequency.

  4. Development and flight evaluation of an augmented stability active controls concept with a small horizontal tail

    NASA Technical Reports Server (NTRS)

    Rising, J. J.; Kairys, A. A.; Maass, C. A.; Siegart, C. D.; Rakness, W. L.; Mijares, R. D.; King, R. W.; Peterson, R. S.; Hurley, S. R.; Wickson, D.

    1982-01-01

    A limited authority pitch active control system (PACS) was developed for a wide body jet transport (L-1011) with a flying horizontal stabilizer. Two dual channel digital computers and the associated software provide command signals to a dual channel series servo which controls the stabilizer power actuators. Input sensor signals to the computer are pitch rate, column-trim position, and dynamic pressure. Control laws are given for the PACS and the system architecture is defined. The piloted flight simulation and vehicle system simulation tests performed to verify control laws and system operation prior to installation on the aircraft are discussed. Modifications to the basic aircraft are described. Flying qualities of the aircraft with the PACS on and off were evaluated. Handling qualities for cruise and high speed flight conditions with the c.g. at 39% mac ( + 1% stability margin) and PACS operating were judged to be as good as the handling qualities with the c.g. at 25% (+15% stability margin) and PACS off.

  5. VS411 Reduced Immune Activation and HIV-1 RNA Levels in 28 Days: Randomized Proof-of-Concept Study for AntiViral-HyperActivation Limiting Therapeutics

    PubMed Central

    Lori, Franco; De Forni, Davide; Katabira, Elly; Baev, Denis; Maserati, Renato; Calarota, Sandra A.; Cahn, Pedro; Testori, Marco; Rakhmanova, Aza; Stevens, Michael R.

    2012-01-01

    Background A new class of antiretrovirals, AntiViral-HyperActivation Limiting Therapeutics (AV-HALTs), has been proposed as a disease-modifying therapy to both reduce Human Immunodeficiency Virus Type 1 (HIV-1) RNA levels and the excessive immune activation now recognized as the major driver of not only the continual loss of CD4+ T cells and progression to Acquired Immunodeficiency Syndrome (AIDS), but also of the emergence of both AIDS-defining and non-AIDS events that negatively impact upon morbidity and mortality despite successful (ie, fully suppressive) therapy. VS411, the first-in-class AV-HALT, combined low-dose, slow-release didanosine with low-dose hydroxycarbamide to accomplish both objectives with a favorable toxicity profile during short-term administration. Five dose combinations were administered as VS411 to test the AV-HALT Proof-of-Concept in HIV-1-infected subjects. Methods Multinational, double-blind, 28-day Phase 2a dose-ranging Proof-of-Concept study of antiviral activity, immunological parameters, safety, and genotypic resistance in 58 evaluable antiretroviral-naïve HIV-1-infected adults. Randomization and allocation to study arms were carried out by a central computer system. Results were analyzed by ANOVA, Kruskal-Wallis, ANCOVA, and two-tailed paired t tests. Results VS411 was well-tolerated, produced significant reductions of HIV-1 RNA levels, increased CD4+ T cell counts, and led to significant, rapid, unprecedented reductions of immune activation markers after 28 days despite incomplete viral suppression and without inhibiting HIV-1-specific immune responses. The didanosine 200 mg/HC 900 mg once-daily formulation demonstrated the greatest antiviral efficacy (HIV-1 RNA: −1.47 log10 copies/mL; CD4+ T cell count: +135 cells/mm3) and fewest adverse events. Conclusions VS411 successfully established the Proof-of-Concept that AV-HALTs can combine antiviral efficacy with rapid, potentially beneficial reductions in the excessive immune system

  6. Concept Mapping

    PubMed Central

    Brennan, Laura K.; Brownson, Ross C.; Kelly, Cheryl; Ivey, Melissa K.; Leviton, Laura C.

    2016-01-01

    Background From 2003 to 2008, 25 cross-sector, multidisciplinary community partnerships funded through the Active Living by Design (ALbD) national program designed, planned, and implemented policy and environmental changes, with complementary programs and promotions. This paper describes the use of concept-mapping methods to gain insights into promising active living intervention strategies based on the collective experience of community representatives implementing ALbD initiatives. Methods Using Concept Systems software, community representatives (n=43) anonymously generated actions and changes in their communities to support active living (183 original statements, 79 condensed statements). Next, respondents (n=26, from 23 partnerships) sorted the 79 statements into self-created categories, or active living intervention approaches. Respondents then rated statements based on their perceptions of the most important strategies for creating community changes (n=25, from 22 partnerships) and increasing community rates of physical activity (n=23, from 20 partnerships). Cluster analysis and multidimensional scaling were used to describe data patterns. Results ALbD community partnerships identified three active living intervention approaches with the greatest perceived importance to create community change and increase population levels of physical activity: changes to the built and natural environment, partnership and collaboration efforts, and land-use and transportation policies. The relative importance of intervention approaches varied according to subgroups of partnerships working with different populations. Conclusions Decision makers, practitioners, and community residents can incorporate what has been learned from the 25 community partnerships to prioritize active living policy, physical project, promotional, and programmatic strategies for work in different populations and settings. PMID:23079266

  7. What a Concept! Using Concept Mapping on Handheld Computers

    ERIC Educational Resources Information Center

    Royer, Regina; Royer, Jeff

    2004-01-01

    When designed properly, concept mapping activities can engage students in meaningful learning. In the process of creating concept maps, students relate new information to more general concepts already held, develop fuller understandings of those general concepts, and recognize new relationships between concepts. Students engage in these activities…

  8. The Effects of Activating the Money Concept on Perseverance and the Preference for Delayed Gratification in Children

    PubMed Central

    Trzcińska, Agata; Sekścińska, Katarzyna

    2016-01-01

    The psychological model of thinking about money assumes that implicit reminders of money lead to self-sufficient motivation. Previous research has demonstrated that children react to money in similar ways to adults. The priming of young children with money related concepts or images has negatively affected their social behavior and social preferences, leading them to make more individualist and less pro-social choices and be less willing to help others. The aim of this research was to investigate the positive influence of money activation on children’s behavior. The participants were 6–8 year old children who do not yet fully understand the instrumental function of money due to their young age. Two experimental studies were performed, the first of which analyzed the effect of perseverance and performance on a challenging task and the second investigated preferences with respect to delaying gratification. Sixty-one children aged 6 took part in the first study and forty-six scout camp participants 6–8 years of age were involved in the second experiment. The results support the hypotheses concerning the effects of money activation stating that (1) money activation influences children’s perseverance and effectiveness in difficult individual tasks, and that (2) it increases children’s preferences for delayed gratification. These results suggest that money has a symbolic power which may exert both positive and negative effects on children’s behavior. Since children between the ages of 6 and 8 do not understand the instrumental function of money fully, certain symbolic meanings of money may have been responsible for the money priming effects. The findings suggest that the symbolic function of money is more primal than its instrumental function and that it probably develops at an earlier stage in life. PMID:27199842

  9. The Effects of Activating the Money Concept on Perseverance and the Preference for Delayed Gratification in Children.

    PubMed

    Trzcińska, Agata; Sekścińska, Katarzyna

    2016-01-01

    The psychological model of thinking about money assumes that implicit reminders of money lead to self-sufficient motivation. Previous research has demonstrated that children react to money in similar ways to adults. The priming of young children with money related concepts or images has negatively affected their social behavior and social preferences, leading them to make more individualist and less pro-social choices and be less willing to help others. The aim of this research was to investigate the positive influence of money activation on children's behavior. The participants were 6-8 year old children who do not yet fully understand the instrumental function of money due to their young age. Two experimental studies were performed, the first of which analyzed the effect of perseverance and performance on a challenging task and the second investigated preferences with respect to delaying gratification. Sixty-one children aged 6 took part in the first study and forty-six scout camp participants 6-8 years of age were involved in the second experiment. The results support the hypotheses concerning the effects of money activation stating that (1) money activation influences children's perseverance and effectiveness in difficult individual tasks, and that (2) it increases children's preferences for delayed gratification. These results suggest that money has a symbolic power which may exert both positive and negative effects on children's behavior. Since children between the ages of 6 and 8 do not understand the instrumental function of money fully, certain symbolic meanings of money may have been responsible for the money priming effects. The findings suggest that the symbolic function of money is more primal than its instrumental function and that it probably develops at an earlier stage in life. PMID:27199842

  10. The Effects of Activating the Money Concept on Perseverance and the Preference for Delayed Gratification in Children.

    PubMed

    Trzcińska, Agata; Sekścińska, Katarzyna

    2016-01-01

    The psychological model of thinking about money assumes that implicit reminders of money lead to self-sufficient motivation. Previous research has demonstrated that children react to money in similar ways to adults. The priming of young children with money related concepts or images has negatively affected their social behavior and social preferences, leading them to make more individualist and less pro-social choices and be less willing to help others. The aim of this research was to investigate the positive influence of money activation on children's behavior. The participants were 6-8 year old children who do not yet fully understand the instrumental function of money due to their young age. Two experimental studies were performed, the first of which analyzed the effect of perseverance and performance on a challenging task and the second investigated preferences with respect to delaying gratification. Sixty-one children aged 6 took part in the first study and forty-six scout camp participants 6-8 years of age were involved in the second experiment. The results support the hypotheses concerning the effects of money activation stating that (1) money activation influences children's perseverance and effectiveness in difficult individual tasks, and that (2) it increases children's preferences for delayed gratification. These results suggest that money has a symbolic power which may exert both positive and negative effects on children's behavior. Since children between the ages of 6 and 8 do not understand the instrumental function of money fully, certain symbolic meanings of money may have been responsible for the money priming effects. The findings suggest that the symbolic function of money is more primal than its instrumental function and that it probably develops at an earlier stage in life.

  11. CONCEPT LEARNING AND CONCEPT TEACHING.

    ERIC Educational Resources Information Center

    GLASER, ROBERT

    REVIEWED ARE THE PSYCHOLOGICAL STUDIES OF CONCEPT LEARNING AS THEY RELATE TO CONCEPT TEACHING. AN ANALYSIS IS MADE OF THE NATURE OF CONCEPT LEARNING AS IT IS STUDIED IN THE PSYCHOLOGIST'S LABORATORY, INCLUDING THE NATURE OF CONCEPT TASKS AS THEY APPEAR IN SUBJECT MATTER LEARNING. THE PRIMARY KINDS OF CONCEPT LEARNING SITUATIONS, INCLUDING THE…

  12. Active bio-monitoring of contamination in aquatic systems--an in situ translocation experiment applying the PICT concept.

    PubMed

    Rotter, Stefanie; Sans-Piché, Frédéric; Streck, Georg; Altenburger, Rolf; Schmitt-Jansen, Mechthild

    2011-01-17

    The environmental risk assessment of toxicants is often derived from chemical monitoring, based on single species tests performed in the laboratory. However, to provide ecologically relevant information, community approaches are required. The aim of this study was to causally link prometryn exposure to community-level effects in complex field situations and to identify response times of adaptation to pollution and recovery from pollution. For this reason sensitivity shifts in communities were detected and related to structural changes within the periphyton community. Furthermore, it was intended to illustrate the possibility of a combined approach of community translocation and sensitivity assessment for active monitoring of polluted sites. Periphyton was grown at a reference (R) and at a polluted (P) site of the river Elbe basin for 26 days, was subsequently transferred from the polluted site to the reference site and vice versa. Sensitivity of communities to prometryn was determined according to the pollution-induced community tolerance (PICT)-concept in short-term tests by measuring photosynthesis inhibition and was related to structural changes in algal class and diatom species composition. Exposure to prometryn was determined using polar organic integrative samplers (POCIS), giving time-weighted average concentrations. Environmental concentrations of prometryn were significantly higher at the polluted site compared to the reference site. Communities grown at the polluted site showed a higher tolerance to prometryn in comparison to the reference site. 17 Days after the translocation to the reference site, EC(50) decreased 2-fold compared to the non-translocated P-community of the same age. By contrast, EC(50) of the community grown at the reference site was 5 times higher after 17 days exposure at the polluted site. Furthermore, P-R communities were less sensitive to prometryn (higher EC(50)) than R-P communities, 24 days after translocation. These changes in

  13. An ontology-based exploration of the concepts and relationships in the activities and participation component of the international classification of functioning, disability and health

    PubMed Central

    2012-01-01

    Background The International Classification of Functioning, Disability and Health (ICF) is a classification of health and health-related issues, aimed at describing and measuring health and disability at both individual and population levels. Here we discuss a preliminary qualitative and quantitative analysis of the relationships used in the Activities and Participation component of ICF, and a preliminary mapping to SUMO (Suggested Upper Merged Ontology) concepts. The aim of the analysis is to identify potential logical problems within this component of ICF, and to understand whether activities and participation might be defined more formally than in the current version of ICF. Results In the relationship analysis, we used four predicates among those available in SUMO for processes (Patient, Instrument, Agent, and subProcess). While at the top level subsumption was used in most cases (90%), at the lower levels the percentage of other relationships rose to 41%. Chapters were heterogeneous in the relationships used and some of the leaves of the tree seemed to represent properties or parts of the parent concept rather than subclasses. Mapping of ICF to SUMO proved partially feasible, with the activity concepts being mapped mostly (but not totally) under the IntentionalProcess concept in SUMO. On the other hand, the participation concept has not been mapped to any upper level concept. Conclusions Our analysis of the relationships within ICF revealed issues related to confusion between classes and their properties, incorrect classifications, and overemphasis on subsumption, confirming what already observed by other researchers. However, it also suggested some properties for Activities that could be included in a more formal model: number of agents involved, the instrument used to carry out the activity, the object of the activity, complexity of the task, and an enumeration of relevant subtasks. PMID:22373520

  14. AST Critical Propulsion and Noise Reduction Technologies for Future Commercial Subsonic Engines: Separate-Flow Exhaust System Noise Reduction Concept Evaluation

    NASA Technical Reports Server (NTRS)

    Janardan, B. A.; Hoff, G. E.; Barter, J. W.; Martens, S.; Gliebe, P. R.; Mengle, V.; Dalton, W. N.; Saiyed, Naseem (Technical Monitor)

    2000-01-01

    This report describes the work performed by General Electric Aircraft Engines (GEAE) and Allison Engine Company (AEC) on NASA Contract NAS3-27720 AoI 14.3. The objective of this contract was to generate quality jet noise acoustic data for separate-flow nozzle models and to design and verify new jet-noise-reduction concepts over a range of simulated engine cycles and flight conditions. Five baseline axisymmetric separate-flow nozzle models having bypass ratios of five and eight with internal and external plugs and 11 different mixing-enhancer model nozzles (including chevrons, vortex-generator doublets, and a tongue mixer) were designed and tested in model scale. Using available core and fan nozzle hardware in various combinations, 28 GEAE/AEC separate-flow nozzle/mixing-enhancer configurations were acoustically evaluated in the NASA Glenn Research Center Aeroacoustic and Propulsion Laboratory. This report describes model nozzle features, facility and data acquisition/reduction procedures, the test matrix, and measured acoustic data analyses. A number of tested core and fan mixing enhancer devices and combinations of devices gave significant jet noise reduction relative to separate-flow baseline nozzles. Inward-flip and alternating-flip core chevrons combined with a straight-chevron fan nozzle exceeded the NASA stretch goal of 3 EPNdB jet noise reduction at typical sideline certification conditions.

  15. A Concept-Map Integrated Dynamic Assessment System for Improving Ecology Observation Competences in Mobile Learning Activities

    ERIC Educational Resources Information Center

    Hung, Pi-Hsia; Hwang, Gwo-Jen; Su, I-Hsiang; Lin, I-Hua

    2012-01-01

    Observation competence plays a fundamental role in outdoor scientific investigation. The computerized concept mapping technique as a Mindtool has shown the potential for enhancing meaningful learning in science education. The purposes of the present study are to develop a concept map integrated mobile learning design for ecology observation and to…

  16. Location and age of foraminifer samples examined by Chevron Petroleum Company paleontologists from more than 2,500 oil test wells in California

    USGS Publications Warehouse

    Brabb, Earl E.

    2011-01-01

    Chevron Petroleum Company in 2001 donated an estimated 50,000 foraminifer slides, 5,000 well logs, geologic and surface locality maps, and paleontologic reports to the California Academy of Sciences and Stanford University for safekeeping, because they stopped or cut back exploration for petroleum deposits in California. The material was loaned to Earl Brabb temporarily so that information useful to the U.S. Geological Survey could be extracted. Among the estimated 5,000 well logs, more than 2,500 were printed on fragile Ozalid paper that had deteriorated by turning brown and hardening so that they could be easily damaged. These 2,516 well logs were scanned to provide a digital copy of the information. The 2,516 wells extend over an area from Eureka in Humboldt County south to the Imperial Valley and from the Pacific Ocean east to the eastern side of the Great Valley and the Los Angeles Basin. The wells are located in 410 7.5-minute quadrangle maps in 42 counties. The digital information herein preserves the data, makes the logs easily distributed to others interested in subsurface geology, and makes previously proprietary information widely available to the public for the first time.

  17. Physical Activity, Physical Self-Concept, and Health-Related Quality of Life of Extreme Early and Late Maturing Adolescent Girls

    ERIC Educational Resources Information Center

    Cumming, Sean P.; Sherar, Lauren B.; Smart, Joanna E. Hunter; Rodrigues, Aristides M. M.; Standage, Martyn; Gillison, Fiona B.; Malina, Robert M.

    2012-01-01

    In this study we tested for differences in physical activity (PA), physical self-concept, and health-related quality of life (HRQoL) between the least and most biologically mature adolescent females within their respective chronological and academic year groups. A total of 222 British female adolescents aged 10 to 14 years (X[bar] age = 12.7…

  18. The Effectiveness of Education and Schooling Activities with Respect to Learning Styles on the Learning of Abstract and Tangible Concepts of Social Studies by Students

    ERIC Educational Resources Information Center

    Seker, Mustafa

    2013-01-01

    This research reviews the effects of education and schooling activities that are conducted with respect to different learning styles on the success of teaching abstract and tangible concepts of 6th Grade Social Studies, and researches whether the demographic variables (age, gender) of the students had any effect on this success levels. To do so, 2…

  19. The Effectiveness of Embedded Teaching through the Most-to-Least Prompting Procedure in Concept Teaching to Children with Autism within Orff-Based Music Activities

    ERIC Educational Resources Information Center

    Eren, Bilgehan; Deniz, Jale; Duzkantar, Ayten

    2013-01-01

    The purpose of this study was to demonstrate the effectiveness of embedded teaching through the most-to-least prompting procedure in concept teaching to children with autism in Orff-based music activities. In this research, being one of the single subject research designs, multiple probe design was used. The generalization effect of the research…

  20. Light-induced self-assembly of active rectification devices.

    PubMed

    Stenhammar, Joakim; Wittkowski, Raphael; Marenduzzo, Davide; Cates, Michael E

    2016-04-01

    Self-propelled colloidal objects, such as motile bacteria or synthetic microswimmers, have microscopically irreversible individual dynamics-a feature they share with all living systems. The incoherent behavior of individual swimmers can be harnessed (or "rectified") by microfluidic devices that create systematic motions that are impossible in equilibrium. We present a computational proof-of-concept study showing that such active rectification devices could be created directly from an unstructured "primordial soup" of light-controlled motile particles, solely by using spatially modulated illumination to control their local propulsion speed. Alongside both microscopic irreversibility and speed modulation, our mechanism requires spatial symmetry breaking, such as a chevron light pattern, and strong interactions between particles, such as volume exclusion, which cause a collisional slowdown at high density. Together, we show how these four factors create a novel, many-body rectification mechanism. Our work suggests that standard spatial light modulator technology might allow the programmable, light-induced self-assembly of active rectification devices from an unstructured particle bath.

  1. Light-induced self-assembly of active rectification devices

    PubMed Central

    Stenhammar, Joakim; Wittkowski, Raphael; Marenduzzo, Davide; Cates, Michael E.

    2016-01-01

    Self-propelled colloidal objects, such as motile bacteria or synthetic microswimmers, have microscopically irreversible individual dynamics—a feature they share with all living systems. The incoherent behavior of individual swimmers can be harnessed (or “rectified”) by microfluidic devices that create systematic motions that are impossible in equilibrium. We present a computational proof-of-concept study showing that such active rectification devices could be created directly from an unstructured “primordial soup” of light-controlled motile particles, solely by using spatially modulated illumination to control their local propulsion speed. Alongside both microscopic irreversibility and speed modulation, our mechanism requires spatial symmetry breaking, such as a chevron light pattern, and strong interactions between particles, such as volume exclusion, which cause a collisional slowdown at high density. Together, we show how these four factors create a novel, many-body rectification mechanism. Our work suggests that standard spatial light modulator technology might allow the programmable, light-induced self-assembly of active rectification devices from an unstructured particle bath. PMID:27051883

  2. Integrating health education and physical activity programming for cardiovascular health promotion among female inmates: A proof of concept study.

    PubMed

    Nair, Uma S; Jordan, Jeremy S; Funk, Daniel; Gavin, Kristin; Tibbetts, Erica; Collins, Bradley N

    2016-05-01

    Female inmate populations in the United States tend to be overweight, physically inactive, experience high stress, and have a history of nicotine and other drug dependence. Thus, they bear an elevated risk of cardiovascular (CV) disease than the general population. However, few evidence-based health interventions exist for this population. This study will test proof of concept, feasibility, and potential efficacy of a multiple health behavior change intervention that integrates CV-health promotion education delivered during a physical activity (PA) program (indoor cycling) tailored to this population. This study uses a quasi-experimental 2-group design with two measurement time-points: baseline and 8-week end of treatment. N=120 incarcerated women (18-59years of age) who are medically cleared for participation in PA will be enrolled. Indoor cycling instructors will be trained to deliver five health education topics over an 8-week period during twice-weekly cycling classes. Topics match the American Heart Association recommendations for CV health: (a) nutrition, (b) PA promotion, (c) weight management, (d) stress management, and (e) smoking cessation and relapse prevention. Modes of intervention include instructor advice, written materials and audio/video clips reviewed during class. CV-related and mental health measures will be assessed at both time-points. Results will guide a full scale efficacy study. Future research in this area has potential to impact the health of female inmates, a high-risk population. Moreover, this multiple health behavior change intervention model represents a community approach to health promotion that could generalize to other underserved populations who may benefit most from similar intervention efforts. PMID:27020419

  3. Addressing key concepts in physical geography through interactive learning activities in an online geo-ICT environment

    NASA Astrophysics Data System (ADS)

    Verstraeten, Gert; Steegen, An; Martens, Lotte

    2016-04-01

    The increasing number of geospatial datasets and free online geo-ICT tools offers new opportunities for education in Earth Sciences. Geospatial technology indeed provides an environment through which interactive learning can be introduced in Earth Sciences curricula. However, the effectiveness of such e-learning approaches in terms of learning outcomes has rarely been addressed. Here, we present our experience with the implementation of digital interactive learning activities within an introductory Physical Geography course attended by 90 undergraduate students in Geography, Geology, Biology and Archaeology. Two traditional lectures were replaced by interactive sessions (each 2 h) in a flexible classroom where students had to work both in team and individually in order to explore some key concepts through the integrated use of geospatial data within Google EarthTM. A first interactive lesson dealt with the classification of river systems and aimed to examine the conditions under which rivers tend to meander or to develop a braided pattern. Students were required to collect properties of rivers (river channel pattern, channel slope, climate, discharge, lithology, vegetation, etc). All these data are available on a global scale and have been added as separate map layers in Google EarthTM. Each student collected data for at least two rivers and added this information to a Google Drive Spreadsheet accessible to the entire group. This resulted in a database of more than one hundred rivers spread over various environments worldwide. In a second phase small groups of students discussed the potential relationships between river channel pattern and its controlling factors. Afterwards, the findings of each discussion group were presented to the entire audience. The same set-up was followed in a second interactive session to explore spatial variations in ecosystem properties such as net primary production and soil carbon content. The qualitative evaluation of both interactive

  4. BASALT 1: Extravehicular Activity Science Operations Concepts under Communication Latency and Bandwidth Constraints at Craters of the Moon, Idaho

    NASA Technical Reports Server (NTRS)

    Chappell, Steven P.; Beaton, Kara; Miller, Matthew J.; Lim, Darlene S. S.; Abercromby, Andrew F. J.

    2017-01-01

    An over-arching goal of the multi-year Biologic Analog Science Associated with Lava Terrains (BASALT) project is to iteratively develop, implement, and evaluate concepts of operations (ConOps) and supporting capabilities intended to enable and enhance human exploration of Mars. Geological and biological scientific fieldwork is being conducted during four total deployments at two high-fidelity Mars analogs, all within simulated Mars mission conditions that are based on current architectural assumptions for Mars exploration missions. Specific capabilities being evaluated include the use of mobile science platforms, extravehicular informatics, communication and navigation packages, advanced science mission planning tools, and scientifically-relevant instrument packages to achieve the project goals. This paper describes the planning, execution, and results of the first field deployment, referred to as BASALT 1, which consisted of a series of 12 simulated extravehicular activities (EVAs) on the lava terrains of Craters of the Moon, Idaho. Scientific objectives of the EVAs related to determination of how microbial communities and habitability correlate with the physical and geochemical characteristics of chemically-altered basalt environments. The concept of operations (ConOps) and capabilities deployed and tested during BASALT 1 were based on extensive data from previous NASA trade studies and analog testing, and the primary research question was whether those ConOps and capabilities would work acceptably when performing real (non-simulated) biological and geological scientific exploration under four different communication scenarios. Specifically, communication latencies of 5 and 15 minutes one-way light time (OWLT) were tested; these delays fall within the range of 4 to 22 minute OWLT delays that would be experienced during a Mars mission. Science operations were also conducted under low bandwidth conditions (0.512 Mb/s uplink, 1.54 Mb/s downlink), representing a

  5. Impact of 3-D seismic data on the Nigerian National Petroleum Corporation/Chevron Nigeria Limited joint venture development drilling program

    SciTech Connect

    Quam, S. )

    1993-09-01

    The Nigerian National Petroleum Corporation/Chevron Nigeria Limited joint venture has been acquiring three-dimensional (3-D) seismic data over its concessions since 1984. To date, 1700 km[sup 2] have been recorded and processed at a cumulative cost of US $39 million. During 1991 - 1992, 20 development wells were drilled based directly on new 3-D seismic interpretations. These wells have added 148 million bbl of oil in new recoverable reserves, and to date have added 37,000 bbl/day to the joint venture's production. In addition, the 3-D interpretations have resulted in a sizable inventory of wells for future development drilling. The new 3-D interpretations provided more accurate pictures of fault patterns, fluid contacts, channel trends, stratigraphic continuity, and velocity/amplitude anomalies. In addition, the 3-D data were invaluable in designing low risk, directional well trajectories to tap relatively thin oil legs under large gas caps. Wells often were programmed to hit several objectives at their respective gas/oil contacts, resulting in maximized net oil sand pays and reducing the risk of gas production. In order to do this, directional [open quotes]sharpshooting,[close quotes] accurate depth conversion of the seismic time maps, was critical. By using the 3-D seismic, checkshot, and sonic data to develop a variable velocity space, well-top prognoses within 50 ft at depths of 6,000-10,000 ft were possible, and were key to the success of the program. As the joint venture acreage becomes more mature, development wells will be drilled for smaller numbers of stacked objectives, and sometimes for single sands. Highly accurate 3-D interpretations and depth conversions will become even more critical in order to tap thinner pay zones in a cost-effect manner.

  6. Threshold Concepts as a Focus for Metalearning Activity: Application of a Research-Developed Mechanism in Undergraduate Engineering

    ERIC Educational Resources Information Center

    Meyer, Jan H. F.; Knight, David B.; Callaghan, David P.; Baldock, Tom E.

    2015-01-01

    This paper reports on the development of metalearning capacity in the learning of a "threshold concept"--capacity of transformative significance relative to metalearning in the general response context of a discipline or subject. The development of metalearning capacity is framed within a protocol that invites students to self-construct…

  7. Enhancing Students' Understanding of the Concept of "Chemical Bonding" by Using Activities Provided on an Interactive Website

    ERIC Educational Resources Information Center

    Frailich, Marcel; Kesner, Miri; Hofstein, Avi

    2009-01-01

    This study investigated the effectiveness of a web-based learning environment in enhancing 10th grade high-school students' understanding of the concept of "chemical bonding". Two groups participated in this study: an experimental group (N = 161) and a comparison one (N = 93). The teachers in the experimental group were asked to implement four…

  8. Developing a Local Instruction Theory for Learning the Concept of Angle through Visual Field Activities and Spatial Representations

    ERIC Educational Resources Information Center

    Bustang, B.; Zulkardi, Z.; Darmawijoyo, H.; Dolk, Maarten; van Eerde, Dolly

    2013-01-01

    This paper reports a study on designing and testing an instructional sequence for the teaching and learning of the concept of angle in Indonesian primary schools. The study's context is employing the current reform movement adopting "Pendidikan Matematika Realistik Indonesia" (an Indonesian version of Realistic Mathematics Education).…

  9. Teaching retirement financial literacy in an undergraduate gerontology classroom: broadening the concept of the tripod or three-legged stool of retirement income utilizing active learning.

    PubMed

    Baker, Hallie E; Brown, Pamela Pitman

    2015-01-01

    The three-legged stool concept is widely used in gerontological and geriatric education as an explanation on how one should fiscally approach his or her retirement. Financial managers, planners, retirees, business owners, even the Social Security Administration uses this metaphor of fiscal soundness in retirement planning. Gerontologists are moving away from the "tripod of retirement income" and "three-legged stool" term, as more often market work is needed for financial security. This activity focuses on the tripod or three-legged stool concepts of retirement planning using active learning, allowing the students to work collaboratively in a group, reflect upon the activity, and most importantly have fun. The game also allows for an expansion of the tripod concepts into the four pillars of economic security, broaching the use of personal assets and the possible need for longer employment. Game scenarios also emphasize macro- and microlevel forces, such as race, gender, health status, education, or marital status, which can influence timing of retirement or the level of retirement income available. The authors include instructions on how to set up the learning experience including worksheets, as well as reflection questions posed throughout the process.

  10. Attitudes to concept maps as a teaching/learning activity in undergraduate health professional education: influence of preferred approach to learning.

    PubMed

    Laight, David W

    2006-03-01

    Pre-prepared concept maps that organise knowledge in a non-linear fashion appeal to a variety of cognitive learning styles and may thus represent an educational tool that supports 'teaching to all types'. However, another central cognitive factor, learning approach, may have a bearing on student take-up of this learning resource. Student attitudes to pre-prepared concept maps introduced in Stage 2 MPharm and BSc Pharmacology lectures were therefore examined in relation to the principal learning orientations according to Duff's 30-item revised approaches to study inventory (RASI). Approximately one half of students (49.6 +/- 4.5%) reported pre-prepared concept maps to be useful to their learning (n = 121). When preferred learning approach was examined, derived from the highest RASI score per individual and excluding ties, 31.9 +/- 4.3%, 29.3 +/- 4.2% and 38.8 +/- 4.5% of students demonstrated a preference for the deep approach (DA), strategic approach (STA) and surface approach (SUA), respectively (P > 0.05, chi2 goodness-of-fit test, n = 116). There was a weak but statistically significant association between preferred learning approach identified by Duff's 30-item RASI and the self-reported usefulness of concept maps (P < 0.05, chi2 test of independence; Cramer's V = 0.235; lambda = 0.193). In contrast, gender was not significantly associated with attitude to concept maps in this student cohort. A preliminary analysis of standardised residuals based on observed and expected frequencies revealed that the greatest contributions to this significant association were: a positive influence of DA and a negative influence of STA, respectively, on attitude to concept maps. These data now indicate a contribution of the principal learning orientations vis-à-vis student attitudes to pre-prepared concept maps when employed alongside more traditional teaching/learning activities in medical and biomedical science education, and may further suggest a role for concept maps in the

  11. Teaching Aerobic Fitness Concepts.

    ERIC Educational Resources Information Center

    Sander, Allan N.; Ratliffe, Tom

    2002-01-01

    Discusses how to teach aerobic fitness concepts to elementary students. Some of the K-2 activities include location, size, and purpose of the heart and lungs; the exercise pulse; respiration rate; and activities to measure aerobic endurance. Some of the 3-6 activities include: definition of aerobic endurance; heart disease risk factors;…

  12. Concept Mapping

    ERIC Educational Resources Information Center

    Technology & Learning, 2005

    2005-01-01

    Concept maps are graphical ways of working with ideas and presenting information. They reveal patterns and relationships and help students to clarify their thinking, and to process, organize and prioritize. Displaying information visually--in concept maps, word webs, or diagrams--stimulates creativity. Being able to think logically teaches…

  13. How Does Physical Activity Intervention Improve Self-Esteem and Self-Concept in Children and Adolescents? Evidence from a Meta-Analysis

    PubMed Central

    Liu, Mingli; Wu, Lang; Ming, Qingsen

    2015-01-01

    Objective To perform a systematic review and meta-analysis for the effects of physical activity intervention on self-esteem and self-concept in children and adolescents, and to identify moderator variables by meta-regression. Design A meta-analysis and meta-regression. Method Relevant studies were identified through a comprehensive search of electronic databases. Study inclusion criteria were: (1) intervention should be supervised physical activity, (2) reported sufficient data to estimate pooled effect sizes of physical activity intervention on self-esteem or self-concept, (3) participants’ ages ranged from 3 to 20 years, and (4) a control or comparison group was included. For each study, study design, intervention design and participant characteristics were extracted. R software (version 3.1.3) and Stata (version 12.0) were used to synthesize effect sizes and perform moderation analyses for determining moderators. Results Twenty-five randomized controlled trial (RCT) studies and 13 non-randomized controlled trial (non-RCT) studies including a total of 2991 cases were identified. Significant positive effects were found in RCTs for intervention of physical activity alone on general self outcomes (Hedges’ g = 0.29, 95% confidence interval [CI]: 0.14 to 0.45; p = 0.001), self-concept (Hedges’ g = 0.49, 95%CI: 0.10 to 0.88, p = 0.014) and self-worth (Hedges’ g = 0.31, 95%CI: 0.13 to 0.49, p = 0.005). There was no significant effect of intervention of physical activity alone on any outcomes in non-RCTs, as well as in studies with intervention of physical activity combined with other strategies. Meta-regression analysis revealed that higher treatment effects were associated with setting of intervention in RCTs (β = 0.31, 95%CI: 0.07 to 0.55, p = 0.013). Conclusion Intervention of physical activity alone is associated with increased self-concept and self-worth in children and adolescents. And there is a stronger association with school-based and gymnasium

  14. Preservice Secondary Teachers' Conceptions from a Mathematical Modeling Activity and Connections to the Common Core State Standards

    ERIC Educational Resources Information Center

    Stohlmann, Micah; Maiorca, Cathrine; Olson, Travis A.

    2015-01-01

    Mathematical modeling is an essential integrated piece of the Common Core State Standards. However, researchers have shown that mathematical modeling activities can be difficult for teachers to implement. Teachers are more likely to implement mathematical modeling activities if they have their own successful experiences with such activities. This…

  15. Science Art: Projects and Activities That Teach Science Concepts and Develop Process Skills. Grades 2-4.

    ERIC Educational Resources Information Center

    Schecter, Deborah

    The activities in this collection are designed to help teachers bring the worlds of science and art into the classroom. Each activity is both a hands-on science investigation and an art experience. As students create satisfying art projects, they utilize science skills such as observing, predicting, investigating, and communicating. The projects…

  16. It's More Fun than It Sounds--Enhancing Science Concepts through Hands-on Activities for Young Children

    ERIC Educational Resources Information Center

    Guha, Smita

    2012-01-01

    To teach young children, teachers choose topics in science that children are curious about. Children's inquisitive nature is reflected through the activities as they make repetitive sounds to find the cause and effect relationship. Teachers can make best use of those invaluable moments by incorporating those activities into science lessons on…

  17. Optimizing the function of upstanding activities in adult patients with acquired lesions of the central nervous system by using the Bobath concept approach - A case report.

    PubMed

    Jelica, Stjepan; Seper, Vesna; Davidović, Erna; Bujisić, Gordana

    2011-01-01

    Nonspecific medical gymnastic therapy may help patients after stroke achieve certain results in terms of efficiency but not in terms of quality of movement. The goal of treatment by Bobath concept is development of movement (effectiveness) and optimization of movement (efficiency). This article presents the case of a 62-year old patient who had experienced a stroke and has difficulties with standing up activities. It underscores the importance of not only recovery of function but also optimization of the function in such patients. PMID:21648353

  18. Annual summary of Immobilized Low-Activity Waste (ILAW) Performance Assessment for 2003 Incorporating the Integrated Disposal Facility Concept

    SciTech Connect

    MANN, F M

    2003-09-01

    To Erik Olds 09/30/03 - An annual summary of the adequacy of the Hanford Immobilized Low-Activity Tank Waste Performance Assessment (ILAW PA) is necessary in each year in which a full performance assessment is not issued.

  19. Real-time neurofeedback using functional MRI could improve down-regulation of amygdala activity during emotional stimulation: a proof-of-concept study.

    PubMed

    Brühl, Annette Beatrix; Scherpiet, Sigrid; Sulzer, James; Stämpfli, Philipp; Seifritz, Erich; Herwig, Uwe

    2014-01-01

    The amygdala is a central target of emotion regulation. It is overactive and dysregulated in affective and anxiety disorders and amygdala activity normalizes with successful therapy of the symptoms. However, a considerable percentage of patients do not reach remission within acceptable duration of treatment. The amygdala could therefore represent a promising target for real-time functional magnetic resonance imaging (rtfMRI) neurofeedback. rtfMRI neurofeedback directly improves the voluntary regulation of localized brain activity. At present, most rtfMRI neurofeedback studies have trained participants to increase activity of a target, i.e. up-regulation. However, in the case of the amygdala, down-regulation is supposedly more clinically relevant. Therefore, we developed a task that trained participants to down-regulate activity of the right amygdala while being confronted with amygdala stimulation, i.e. negative emotional faces. The activity in the functionally-defined region was used as online visual feedback in six healthy subjects instructed to minimize this signal using reality checking as emotion regulation strategy. Over a period of four training sessions, participants significantly increased down-regulation of the right amygdala compared to a passive viewing condition to control for habilitation effects. This result supports the concept of using rtfMRI neurofeedback training to control brain activity during relevant stimulation, specifically in the case of emotion, and has implications towards clinical treatment of emotional disorders.

  20. Real-time neurofeedback using functional MRI could improve down-regulation of amygdala activity during emotional stimulation: a proof-of-concept study.

    PubMed

    Brühl, Annette Beatrix; Scherpiet, Sigrid; Sulzer, James; Stämpfli, Philipp; Seifritz, Erich; Herwig, Uwe

    2014-01-01

    The amygdala is a central target of emotion regulation. It is overactive and dysregulated in affective and anxiety disorders and amygdala activity normalizes with successful therapy of the symptoms. However, a considerable percentage of patients do not reach remission within acceptable duration of treatment. The amygdala could therefore represent a promising target for real-time functional magnetic resonance imaging (rtfMRI) neurofeedback. rtfMRI neurofeedback directly improves the voluntary regulation of localized brain activity. At present, most rtfMRI neurofeedback studies have trained participants to increase activity of a target, i.e. up-regulation. However, in the case of the amygdala, down-regulation is supposedly more clinically relevant. Therefore, we developed a task that trained participants to down-regulate activity of the right amygdala while being confronted with amygdala stimulation, i.e. negative emotional faces. The activity in the functionally-defined region was used as online visual feedback in six healthy subjects instructed to minimize this signal using reality checking as emotion regulation strategy. Over a period of four training sessions, participants significantly increased down-regulation of the right amygdala compared to a passive viewing condition to control for habilitation effects. This result supports the concept of using rtfMRI neurofeedback training to control brain activity during relevant stimulation, specifically in the case of emotion, and has implications towards clinical treatment of emotional disorders. PMID:24241476

  1. The application of One Health concept to an outdoor problem-based learning activity for veterinary students

    PubMed Central

    Putra, T. A. Tengku Rinalfi; Hezmee, Mohd Noor Mohd; Farhana, N. B.; Hassim, H. A.; Intan-Shameha, A. R.; Lokman, I. H.; Hamali, A. Yusof; Salisi, M. S.; Ghani, A. A. A.; Shahudin, M. S.; Qayyum, M. A. L.; Hafandi, A.; Speare, R.; Fenwick, S. G.

    2016-01-01

    Background: The One Health (OH) approach, which seeks to bring together human and animal health, is particularly suited to the effective management of zoonotic diseases across both sectors. To overcome professional silos, OH needs to be taught at the undergraduate level. Here, we describe a problem-based learning activity using the OH approach that was conducted outdoors for 3rd-year veterinary students in Malaysia. Materials and Methods: A total of 118 students, divided into two groups, completed the activity which spanned 1½ days at a deer park adjacent to a wilderness area. Students were asked to evaluate the activity using an online survey that had quantitative and qualitative components. Results: Response rate was 69.5%. The activity was rated excellent by 69.5% and good by 30.4%. Levels of satisfaction were high on a range of criteria. 97.5% of students intended to take action in their studies as a result of what they had learned. Conclusions: Delivery of an outdoor problem-based learning activity using OH approach was very successful in terms of participation, knowledge delivery and understanding, and the willingness of students to integrate OH into their future practice. For the improvement of future programs, the involvement of other disciplines (such as Medical, Biology, Biotechnology, Biomedical, and Public Health) is being considered. PMID:27733795

  2. Analyzing the Function of Cartilage Replacements: A Laboratory Activity to Teach High School Students Chemical and Tissue Engineering Concepts

    ERIC Educational Resources Information Center

    Renner, Julie N.; Emady, Heather N.; Galas, Richards J., Jr.; Zhange, Rong; Baertsch, Chelsey D.; Liu, Julie C.

    2013-01-01

    A cartilage tissue engineering laboratory activity was developed as part of the Exciting Discoveries for Girls in Engineering (EDGE) Summer Camp sponsored by the Women In Engineering Program (WIEP) at Purdue University. Our goal was to increase awareness of chemical engineering and tissue engineering in female high school students through a…

  3. Investigating the Effectiveness of an Active Learning Based-Interactive Conceptual Instruction (ALBICI) on Electric Field Concept

    ERIC Educational Resources Information Center

    Samsudin, Achmad; Suhandi, Andi; Rusdiana, Dadi; Kaniawati, Ida; Costu, Bayram

    2016-01-01

    The aim of this study was to develop an Active Learning Based-Interactive Conceptual Instruction (ALBICI) model through PDEODE*E tasks (stands for Predict, Discuss, Explain, Observe, Discuss, Explore, and Explain) for promoting conceptual change and investigating its effectiveness of pre-service physics teachers' understanding on electric field…

  4. Using a Hands-On Hydrogen Peroxide Decomposition Activity to Teach Catalysis Concepts to K-12 Students

    ERIC Educational Resources Information Center

    Cybulskis, Viktor J.; Ribeiro, Fabio H.; Gounder, Rajamani

    2016-01-01

    A versatile and transportable laboratory apparatus was developed for middle and high school (6th-12th grade) students as part of a hands-on outreach activity to estimate catalytic rates of hydrogen peroxide decomposition from oxygen evolution rates measured by using a volumetric displacement method. The apparatus was constructed with inherent…

  5. Development and investigation of a semi-active polar planar haptic interface using the digital resistance map concept

    NASA Astrophysics Data System (ADS)

    Asadi, Ehsan; Arzanpour, Siamak

    2014-05-01

    The growing demand for haptic technologies in recent years has motivated novel approaches in developing haptic interfaces and control algorithms. Semi-active haptic interfaces, in general, have the advantage of addressing safety concerns which adversely affect their active counterparts. This paper presents the development of a planar semi-active haptic interface using magnetorheological (MR) dampers. The ability of MR dampers to produce controllable resistance forces is the key reason for their utilization in the proposed haptic interface. The proposed planar semi-active haptic interface consists of linear and rotary MR dampers. Each of the MR dampers is modeled experimentally using the Bouc-Wen model. A haptic rendering algorithm called the digital resistance map (DRM) is also developed to control MR dampers. DRM is a high-fidelity haptic rendering algorithm, and proved to be effective to create comprehensive force feedback for operators. MATLAB/Simulink® is used for implementing several DRM scenarios for generating haptic enabled virtual environments. The experimental results demonstrate the effectiveness of the proposed haptic interface and rendering algorithm.

  6. Energy Use and the Environment. Concepts & Activities for the Classroom: Mathematics Module. Environmental Education Supplementary Instructional Guide.

    ERIC Educational Resources Information Center

    Hawaii State Dept. of Education, Honolulu. Office of Instructional Services.

    As part of a comprehensive, interdisciplinary environmental education program for elementary and secondary education in Hawaii, this teaching guide provides a variety of energy education activities for secondary school mathematics. An extensive introduction outlines the total program and how it fits into the general education program and explains…

  7. Chimeric proteins combining phosphatase and cellulose-binding activities: proof-of-concept and application in the hydrolysis of paraoxon.

    PubMed

    Gonçalves, Larissa M; Chaimovich, Hernan; Cuccovia, Iolanda M; Marana, Sandro R

    2014-05-01

    Phosphatases for organophosphate degradation and carbohydrate-binding domains (CBMs) have potential biotechnological applications. As a proof-of-concept, a soluble chimeric protein that combines acid phosphatase (AppA) from Escherichia coli and a CBM from Xanthomonas axonopodis pv. citri (AppA-CBM) was produced in E.coli. AppACBM adsorbed in microcrystalline cellulose Avicel PH101 catalyzed the hydrolysis of p-nitrophenyl phosphate (PNPP). The binding to microcrystalline cellulose displayed saturation behavior with an apparent binding constant (Kb) of 22 ± 5 mg and a maximum binding (Bmax) of 1.500 ± 0.001 enzyme units. Binding was highest at pH 2.5 and decreased above pH 6.5, as previously observed for family 2 CBMs. The Km values for PNPP of AppA-CBM and native AppA were identical (2.7 mM). To demonstrate that this strategy for protein engineering has practical applications and is largely functional, even for phosphatases exhibiting diverse folds, a chimeric protein combining human paraoxonase 1 (hPON1) and the CBM was produced. Both PON1-CBM and hPON1 had identical Km values for paraoxon (1.3 mM). Additionally, hPON1 bound to microcrystalline cellulose with a Kb of 27 ± 3 mg, the same as that observed for AppA-CBM. These data show that the phosphatase domains are as functional in both of the chimeric proteins as they are in the native enzymes and that the CBM domain maintains the same cellulose affinity. Therefore, the engineering of chimeric proteins combining domains of phosphatases and CBMs is fully feasible, resulting in chimeric enzymes that exhibit potential for OP detoxification. PMID:24555432

  8. Porphyromonas gingivalis Participates in Pathogenesis of Human Abdominal Aortic Aneurysm by Neutrophil Activation. Proof of Concept in Rats

    PubMed Central

    Delbosc, Sandrine; Alsac, Jean-Marc; Journe, Clement; Louedec, Liliane; Castier, Yves; Bonnaure-Mallet, Martine; Ruimy, Raymond; Rossignol, Patrick; Bouchard, Philippe; Michel, Jean-Baptiste; Meilhac, Olivier

    2011-01-01

    Background Abdominal Aortic Aneurysms (AAAs) represent a particular form of atherothrombosis where neutrophil proteolytic activity plays a major role. We postulated that neutrophil recruitment and activation participating in AAA growth may originate in part from repeated episodes of periodontal bacteremia. Methods and Findings Our results show that neutrophil activation in human AAA was associated with Neutrophil Extracellular Trap (NET) formation in the IntraLuminal Thrombus, leading to the release of cell-free DNA. Human AAA samples were shown to contain bacterial DNA with high frequency (11/16), and in particular that of Porphyromonas gingivalis (Pg), the most prevalent pathogen involved in chronic periodontitis, a common form of periodontal disease. Both DNA reflecting the presence of NETs and antibodies to Pg were found to be increased in plasma of patients with AAA. Using a rat model of AAA, we demonstrated that repeated injection of Pg fostered aneurysm development, associated with pathological characteristics similar to those observed in humans, such as the persistence of a neutrophil-rich luminal thrombus, not observed in saline-injected rats in which a healing process was observed. Conclusions Thus, the control of periodontal disease may represent a therapeutic target to limit human AAA progression. PMID:21533243

  9. Brief reminiscence activities improve state well-being and self-concept in young adults: a randomised controlled experiment.

    PubMed

    Hallford, David John; Mellor, David

    2016-11-01

    Reminiscence-based psychotherapies have been demonstrated to have robust effects on a range of therapeutic outcomes. However, little research has been conducted on the immediate effects of guided activities they are composed of, or how these might differ dependent on the type of reminiscence. The current study utilised a controlled experimental design, whereby 321 young adults (mean age = 25.5 years, SD = 3.0) were randomised to one of four conditions of online reminiscence activity: problem-solving (successful coping experiences), identity (self-defining events contributing to a meaningful and continuous personal identity), bitterness revival (negative or adverse events), or a control condition (any memory from their past). Participants recalled autobiographical memories congruent with the condition, and answered questions to facilitate reflection on the memories. The results indicated that problem-solving and identity reminiscence activities caused significant improvements in self-esteem, meaning in life, self-efficacy and affect, whereas no effects were found in the bitterness revival and control conditions. Problem-solving reminiscence also caused a small effect in increasing perceptions of a life narrative/s. Differences between the conditions did not appear to be explained by the positive-valence of memories. These results provide evidence for the specific effects of adaptive types of problem-solving and identity reminiscence in young adults.

  10. Activities.

    ERIC Educational Resources Information Center

    Kincaid, Charlene; And Others

    1993-01-01

    Presents an activity in which students collect and organize data from a real-world simulation of the scientific concept of half life. Students collect data using a marble sifter, analyze the data using a graphing calculator, and determine an appropriate mathematical model. Includes reproducible worksheets. (MDH)

  11. Present concept on current water protection and remediation activities for the areas contaminated by the 1986 Chernobyl accident.

    PubMed

    Voitsekhovitch, O; Prister, B; Nasvit, O; Los, I; Berkovski, V

    1996-07-01

    The results of radiation monitoring data and migration pathway analysis of water bodies within areas affected by the 1986 Chernobyl accident provide a unique opportunity for decision-makers working in other extensively contaminated regions to optimize their approaches to surface and groundwater protection. Most engineering measures within the Chernobyl 30-km exclusion zone were focused on preventing secondary contamination of surface and groundwater from entering the Pripyat River and the Kiev Reservoir. However, implementation of these measures required huge financial and human resources. Therefore, lessons about post-accidental water protection activities can be learned from the Chernobyl example. PMID:8655324

  12. Present concept on current water protection and remediation activities for the areas contaminated by the 1986 Chernobyl accident

    SciTech Connect

    Voitsekhovitch, O.; Prister, B.; Nasvit, O.; Los, I.; Berkovski, V.

    1996-07-01

    The results of radiation monitoring data and migration pathway analysis of water bodies within areas affected by the 1986 Chernobyl accident provide a unique opportunity for decision-makers working in other extensively contaminated regions to optimize their approaches to surface and groundwater protection. Most engineering measures within the Chernobyl 30-km exclusion zone were focused on preventing secondary contamination of surface and groundwater from entering the Pripyat River and the Kiev Reservoir. However, implementation of these measures required huge financial and human resources. Therefore, lessons about post-accidental water protection activities can be learned form the Chernobyl example. 9 refs., 9 figs.

  13. Present concept on current water protection and remediation activities for the areas contaminated by the 1986 Chernobyl accident.

    PubMed

    Voitsekhovitch, O; Prister, B; Nasvit, O; Los, I; Berkovski, V

    1996-07-01

    The results of radiation monitoring data and migration pathway analysis of water bodies within areas affected by the 1986 Chernobyl accident provide a unique opportunity for decision-makers working in other extensively contaminated regions to optimize their approaches to surface and groundwater protection. Most engineering measures within the Chernobyl 30-km exclusion zone were focused on preventing secondary contamination of surface and groundwater from entering the Pripyat River and the Kiev Reservoir. However, implementation of these measures required huge financial and human resources. Therefore, lessons about post-accidental water protection activities can be learned from the Chernobyl example.

  14. A rhodium/silicon co-electrocatalyst design concept to surpass platinum hydrogen evolution activity at high overpotentials

    PubMed Central

    Zhu, Lili; Lin, Haiping; Li, Youyong; Liao, Fan; Lifshitz, Yeshayahu; Sheng, Minqi; Lee, Shuit-Tong; Shao, Mingwang

    2016-01-01

    Currently, platinum-based electrocatalysts show the best performance for hydrogen evolution. All hydrogen evolution reaction catalysts should however obey Sabatier's principle, that is, the adsorption energy of hydrogen to the catalyst surface should be neither too high nor too low to balance between hydrogen adsorption and desorption. To overcome the limitation of this principle, here we choose a composite (rhodium/silicon nanowire) catalyst, in which hydrogen adsorption occurs on rhodium with a large adsorption energy while hydrogen evolution occurs on silicon with a small adsorption energy. We show that the composite is stable with better hydrogen evolution activity than rhodium nanoparticles and even exceeding those of commercial platinum/carbon at high overpotentials. The results reveal that silicon plays a key role in the electrocatalysis. This work may thus open the door for the design and fabrication of electrocatalysts for high-efficiency electric energy to hydrogen energy conversion. PMID:27447292

  15. A rhodium/silicon co-electrocatalyst design concept to surpass platinum hydrogen evolution activity at high overpotentials.

    PubMed

    Zhu, Lili; Lin, Haiping; Li, Youyong; Liao, Fan; Lifshitz, Yeshayahu; Sheng, Minqi; Lee, Shuit-Tong; Shao, Mingwang

    2016-01-01

    Currently, platinum-based electrocatalysts show the best performance for hydrogen evolution. All hydrogen evolution reaction catalysts should however obey Sabatier's principle, that is, the adsorption energy of hydrogen to the catalyst surface should be neither too high nor too low to balance between hydrogen adsorption and desorption. To overcome the limitation of this principle, here we choose a composite (rhodium/silicon nanowire) catalyst, in which hydrogen adsorption occurs on rhodium with a large adsorption energy while hydrogen evolution occurs on silicon with a small adsorption energy. We show that the composite is stable with better hydrogen evolution activity than rhodium nanoparticles and even exceeding those of commercial platinum/carbon at high overpotentials. The results reveal that silicon plays a key role in the electrocatalysis. This work may thus open the door for the design and fabrication of electrocatalysts for high-efficiency electric energy to hydrogen energy conversion. PMID:27447292

  16. Current concepts on integrative safety assessment of active substances of botanical, mineral or chemical origin in homeopathic medicinal products within the European regulatory framework.

    PubMed

    Buchholzer, Marie-Luise; Werner, Christine; Knoess, Werner

    2014-03-01

    For active substances of botanical, mineral or chemical origin processed in homeopathic medicinal products for human use, the adequate safety principles as with other human medicinal products are applied in line with the European regulatory framework. In homeopathy, nonclinical safety assessment is facing a particular challenge because of a multitude and diversity of source materials used and due to rarely available toxicological data. Thus, current concepts applied by the national regulatory authority in Germany (BfArM) on integrative safety assessment of raw materials used in homeopathic medicinal products involve several evaluation approaches like the use of the Lowest Human Recommended Dose (LHRD), toxicological limit values, Threshold of Toxicological Concern (TTC), data from food regulation or the consideration of unavoidable environmental or dietary background exposure. This publication is intended to further develop and clarify the practical use of these assessment routes by exemplary application on selected homeopathic preparations. In conclusion, the different approaches are considered a very useful scientific and simultaneously pragmatic procedure in differentiated risk assessment of homeopathic medicinal products. Overall, this paper aims to increase the visibility of the safety issues in homeopathy and to stimulate scientific discussion of worldwide existing regulatory concepts on homeopathic medicinal products.

  17. Pre-Service Teachers Enhance Climate Literacy Through Writing Children's Books on Climate Literacy Concepts and Implementing Related Activities in the PK-12 Classroom

    NASA Astrophysics Data System (ADS)

    Walton-Jaggers, L. J.

    2014-12-01

    Grambling State University faculty participated in NICE workshops during 2011, 2012, and 2013 that were designed to help pre-service teachers increase their knowledge about global climate change through the use of NASA Earth observation sets. The faculty members were encouraged to infuse climate education projects and activities into their courses from information and resources provided during the workshops. As a result, pre-service teacher candidates in the Department of Curriculum and Instruction of the College of Education at Grambling State University have written Children's Literature that specifically focused on different climate change concepts. This project has served as the culminating Climate Change Signature Project that was designed to promote increased opportunities for PK-12 students to expand their knowledge and understanding of climate literacy concepts while enhancing Reading/Literacy skills. The pre-service teacher candidates completed several sequential steps in preparing for the culminating project. This paper will include the presentation ofseveral formal and informal assessments that were used to determine the impact of the project on the teacher candidates and their students.

  18. The Io Plasma Torus: Motivation for Abandoning the "Active Sector" Concept in Favor of System IV Modulation

    NASA Astrophysics Data System (ADS)

    Morgenthaler, J. P.; Oliversen, R. J.; Marconi, M.; Woodward, R. C., Jr.

    2014-12-01

    We use an extensive spectroscopic dataset of 1000 observations of Io in [OI] 6300A, presented by Oliversen et al. (2001), narrow-band images of the torus in [SII] 6731A, and HST/STIS EUV observations of Io and its environs to confirm that the Io [OI] flux is an excellent proxy for the electron density in the Io plasma to torus (IPT). Furthermore, we find: (1) A careful statistical analysis of short-term variations in this dataset (20 min to 1 hour), previously suspected to be from flux tube interchange (Oliversen et al. 2001, Morgenthaler et al. 2012) are, in fact, consistent with the expected statistical variation of the parent population of observations. (2) The semi-empirical IPT model developed by W. Smyth (Oliversen et al. 2001; Smyth, Peterson, & Marconi 2011) fits the overall trends in the data reasonably well, with notable exceptions. (3) There may be a link between what was previously known the "active sector" at system III longitudes of 170 ~ 230 degrees and the modulation in IPT plasma density caused by the beating between system III and system IV, predicted by Hess et al. (2011). Conclusion: a simple modification to the W. Smyth semi-empirical torus model to incorporate a system IV-controlled density enhancement, rather than a fixed "active sector" in system III, should enable the model to "lock in" more readily to our extensive set of [OI] 6300A observations recorded between 1990 and 2008. This will provide detailed information about the flow of mass and energy in the IPT during the Galileo, Ulysses, Cassini, and New Horizons missions. Additional observations are planned during NASA's upcoming Juno mission. This work was supported by NASA Planetary Research Program RTOP 344-32-40 to GSFC and grants NAGW-3319 and NAG5-6787 to the University of Wisconsin--Madison, STIS contract NAS5-30131 to the University of Wisconsin--Madison and NASA Outer Planets Research Program grant NNX11AM43G to PSI.

  19. Cyclic AMP Analog Blocks Kinase Activation by Stabilizing Inactive Conformation: Conformational Selection Highlights a New Concept in Allosteric Inhibitor Design*

    PubMed Central

    Badireddy, Suguna; Yunfeng, Gao; Ritchie, Mark; Akamine, Pearl; Wu, Jian; Kim, Choel W.; Taylor, Susan S.; Qingsong, Lin; Swaminathan, Kunchithapadam; Anand, Ganesh S.

    2011-01-01

    The regulatory (R) subunit of protein kinase A serves to modulate the activity of protein kinase A in a cAMP-dependent manner and exists in two distinct and structurally dissimilar, end point cAMP-bound “B” and C-subunit-bound “H”-conformations. Here we report mechanistic details of cAMP action as yet unknown through a unique approach combining x-ray crystallography with structural proteomics approaches, amide hydrogen/deuterium exchange and ion mobility mass spectrometry, applied to the study of a stereospecific cAMP phosphorothioate analog and antagonist((Rp)-cAMPS). X-ray crystallography shows cAMP-bound R-subunit in the B form but surprisingly the antagonist Rp-cAMPS-bound R-subunit crystallized in the H conformation, which was previously assumed to be induced only by C-subunit-binding. Apo R-subunit crystallized in the B form as well but amide exchange mass spectrometry showed large differences between apo, agonist and antagonist-bound states of the R-subunit. Further ion mobility reveals the apo R-subunit as an ensemble of multiple conformations with collisional cross-sectional areas spanning both the agonist and antagonist-bound states. Thus contrary to earlier studies that explained the basis for cAMP action through “induced fit” alone, we report evidence for conformational selection, where the ligand-free apo form of the R-subunit exists as an ensemble of both B and H conformations. Although cAMP preferentially binds the B conformation, Rp-cAMPS interestingly binds the H conformation. This reveals the unique importance of the equatorial oxygen of the cyclic phosphate in mediating conformational transitions from H to B forms highlighting a novel approach for rational structure-based drug design. Ideal inhibitors such as Rp-cAMPS are those that preferentially “select” inactive conformations of target proteins by satisfying all “binding” constraints alone without inducing conformational changes necessary for activation. PMID:21081668

  20. Tetrachlorofluorescein TInsP as a Substrate Analog Probe for Measuring Phytase Activity in Surface Water: Proof of Concept.

    PubMed

    Berry, Duane F; Harich, Kim

    2013-01-01

    An innovative approach for measuring phytase activity (PA) in surface water is presented. A substrate analog of -inositol hexakis(dihydrogen) phosphate (InsP), commonly referred to as phytic acid, 1--5--(1-oxo-1-(2' ,4,7,7' -tetrachloro-3',6'-dihydroxy-3-oxo-3H-spiro[isobenzofuran-1,9'-xanthen]-6-yl)-5,8,11-trioxa-2-azatridecan-13-yl)-inositol 1,2,3,4,6-pentakis--(dihydrogen) phosphate, referred to as tetrachlorofluorescein (TET) tethered (T)InsP, has been developed that can be used to monitor the (phytase-catalyzed) phosphate ester bond-cleavage reaction. Test phytases, (wheat [4-] and [3-] phytase) sequentially remove phosphate groups from TET TInsP, producing dephosphorylated probe species that were readily separated by reversed-phase high-performance liquid chromatography (RP-HPLC). Because dephosphorylated probe species retain the TET group, highly sensitive quantification could be achieved using fluorescence detection (excitation/emission ' = 245/540 nm). Calibration curves for TET TInsP, which could be used as a standard for quantifying all probe species, were linear ( > 0.999) over the range of concentrations tested. Phytase-generated dephosphorylated probe species were characterized or identified using RP-HPLC with mass spectrometry. Results of mass spectrometry analysis show that the RP-HPLC system was capable of distinguishing between dephosphorylated probe species at the regioisomeric level. The TET TInsP molecular probe was used to successfully measure PA in pond water. We found that the PA associated with the particulate plus water-soluble fraction was greater than that observed for the water-soluble fraction alone. Moreover, it appeared that 4- and 3-phytase were active in pond water based on an analysis of the chromatographic profile (i.e., elution sequence) of dephosphorylated probe species produced. The advent of a fluorescent substrate analog of InsP affords environmental scientists with the means to unambiguously quantify an extremely small

  1. The concept of sign in the work of Vygotsky, Winnicott and Bakhtin: further integration of object relations theory and activity theory.

    PubMed

    Leiman, M

    1992-09-01

    In a recent paper Ryle introduced the idea of integrating object relations theory and activity theory, a conceptual tradition originated by Vygotsky and developed by a number of Soviet psychologists during the previous decades. A specific aspect of this integrative perspective will be examined, implied in Ryle's paper but not elaborated by him. It is the issue of sign mediation which was Vygotsky's primary contribution to the methodological problems of modern psychology. The aim is to show that object relations theory, especially the work of Winnicott, may bring fresh understanding into Vygotsky's early notions. It is further claimed that, by introducing the contribution of Mikhail Bakhtin and his circle to the notion of sign mediation, the profundity in Winnicott's understanding of the transitional object and of the potential space may be more fully appreciated. At the same time the ideas of Winnicott and Bakhtin will jointly clarify the limitations in Vygotsky's sign conception. PMID:1390355

  2. Biomolecular structure manipulation using tailored electromagnetic radiation: a proof of concept on a simplified model of the active site of bacterial DNA topoisomerase.

    PubMed

    Jarukanont, Daungruthai; Coimbra, João T S; Bauerhenne, Bernd; Fernandes, Pedro A; Patel, Shekhar; Ramos, Maria J; Garcia, Martin E

    2014-10-21

    We report on the viability of breaking selected bonds in biological systems using tailored electromagnetic radiation. We first demonstrate, by performing large-scale simulations, that pulsed electric fields cannot produce selective bond breaking. Then, we present a theoretical framework for describing selective energy concentration on particular bonds of biomolecules upon application of tailored electromagnetic radiation. The theory is based on the mapping of biomolecules to a set of coupled harmonic oscillators and on optimal control schemes to describe optimization of temporal shape, the phase and polarization of the external radiation. We have applied this theory to demonstrate the possibility of selective bond breaking in the active site of bacterial DNA topoisomerase. For this purpose, we have focused on a model that was built based on a case study. Results are given as a proof of concept.

  3. Neutron intensity monitor with activation foil for p-Li neutron source for BNCT--Feasibility test of the concept.

    PubMed

    Murata, Isao; Otani, Yuki; Sato, Fuminobu

    2015-12-01

    Proton-lithium (p-Li) reaction is being examined worldwide as a candidate nuclear production reaction for accelerator based neutron source (ABNS) for BNCT. In this reaction, the emitted neutron energy is not so high, below 1 MeV, and especially in backward angles the energy is as low as about 100 keV. The intensity measurement was thus known to be difficult so far. In the present study, a simple method was investigated to monitor the absolute neutron intensity of the p-Li neutron source by employing the foil activation method based on isomer production reactions in order to cover around several hundreds keV. As a result of numerical examination, it was found that (107)Ag, (115)In and (189)Os would be feasible. Their features found out are summarized as follows: (107)Ag: The most convenient foil, since the half life is short. (115)In: The accuracy is the best at 0°, though it cannot be used for backward angles. And (189)Os: Suitable nuclide which can be used in backward angles, though the gamma-ray energy is a little too low. These would be used for p-Li source monitoring depending on measuring purposes in real BNCT scenes. PMID:26242557

  4. Plasma-activated medium suppresses choroidal neovascularization in mice: a new therapeutic concept for age-related macular degeneration.

    PubMed

    Ye, Fuxiang; Kaneko, Hiroki; Nagasaka, Yosuke; Ijima, Ryo; Nakamura, Kae; Nagaya, Masatoshi; Takayama, Kei; Kajiyama, Hiroaki; Senga, Takeshi; Tanaka, Hiromasa; Mizuno, Masaaki; Kikkawa, Fumitaka; Hori, Masaru; Terasaki, Hiroko

    2015-01-01

    Choroidal neovascularization (CNV) is the main pathogenesis of age-related macular degeneration (AMD), which leads to severe vision loss in many aged patients in most advanced country. CNV compromises vision via hemorrhage and retinal detachment on account of pathological neovascularization penetrating the retina. Plasma medicine represents the medical application of ionized gas "plasma" that is typically studied in the field of physical science. Here we examined the therapeutic ability of plasma-activated medium (PAM) to suppress CNV. The effect of PAM on vascularization was assessed on the basis of human retinal endothelial cell (HREC) tube formation. In mice, laser photocoagulation was performed to induce CNV (laser-CNV), followed by intravitreal injection of PAM. N-Acetylcysteine was used to examine the role of reactive oxygen species in PAM-induced CNV suppression. Fundus imaging, retinal histology examination, and electroretinography (ERG) were also performed to evaluate PAM-induced retinal toxicity. Interestingly, HREC tube formation and laser-CNV were both reduced by treatment with PAM. N-acetylcysteine only partly neutralized the PAM-induced reduction in laser-CNV. In addition, PAM injection had no effect on regular retinal vessels, nor did it show retinal toxicity in vivo. Our findings indicate the potential of PAM as a novel therapeutic agent for suppressing CNV.

  5. Roles of changes in active glutamine transport in brain edema development during hepatic encephalopathy: an emerging concept.

    PubMed

    Zielińska, Magdalena; Popek, Mariusz; Albrecht, Jan

    2014-01-01

    Excessive glutamine (Gln) synthesis in ammonia-overloaded astrocytes contributes to astrocytic swelling and brain edema, the major complication of hepatic encephalopathy (HE). Much of the newly formed Gln is believed to enter mitochondria, where it is recycled to ammonia, which causes mitochondrial dysfunction (a "Trojan horse" mode of action). A portion of Gln may increase osmotic pressure in astrocytes and the interstitial space, directly and independently contributing to brain tissue swelling. Here we discuss the possibility that altered functioning of Gln transport proteins located in the cellular or mitochondrial membranes, modulates the effects of increased Gln synthesis. Accumulation of excess Gln in mitochondria involves a carrier-mediated transport which is activated by ammonia. Studies on the expression of the cell membrane N-system transporters SN1 (SNAT3) and SN2 (SNAT5), which mediate Gln efflux from astrocytes rendered HE model-dependent effects. HE lowered the expression of SN1 at the RNA and protein level in the cerebral cortex (cc) in the thioacetamide (TAA) model of HE and the effect paralleled induction of cerebral cortical edema. Neither SN1 nor SN2 expression was affected by simple hyperammonemia, which produces no cc edema. TAA-induced HE is also associated with decreased expression of mRNA coding for the system A carriers SAT1 and SAT2, which stimulate Gln influx to neurons. Taken together, changes in the expression of Gln transporters during HE appear to favor retention of Gln in astrocytes and/or the interstitial space of the brain. HE may also affect arginine (Arg)/Gln exchange across the astrocytic cell membrane due to changes in the expression of the hybrid Arg/Gln transporter y(+)LAT2. Gln export from brain across the blood-brain barrier may be stimulated by HE via its increased exchange with peripheral tryptophan. PMID:24072671

  6. Examination of the Early Diagnostic Applicability of Active Dynamic Thermography for Burn Wound Depth Assessment and Concept Analysis.

    PubMed

    Prindeze, Nicholas J; Fathi, Payam; Mino, Matthew J; Mauskar, Neil A; Travis, Taryn E; Paul, Dereck W; Moffatt, Lauren T; Shupp, Jeffrey W

    2015-01-01

    Despite advances in perfusion imaging, burn wound imaging technology continues to lag behind that of other fields. Quantification of blood flow is able to predict time for healing, but clear assessment of burn depth is still questionable. Active dynamic thermography (ADT) is a noncontact imaging modality capable of distinguishing tissue of different thermal conductivities. Utilizing the abnormal heat transfer properties of the burn zones, we examined whether ADT was useful in the determination of burn depth in a model of early burn wound evaluation. Duroc pigs (castrated male; n = 3) were anesthetized, and two burns were created with an aluminum billet at 3 and 12 seconds. These contact times resulted in superficial partial and deep partial thickness burn wounds, respectively. ADT and laser Doppler imaging (LDI) imaging were performed every 30 minutes postburn for a total of five imaging sessions ending 150 minutes postburn. For ADT, imaging excitation was performed for 42-120 seconds with dual quartz-infrared lamps, and subsequent infrared image capture was performed for 300 seconds. MATLAB-assisted image analysis was performed to determine burn zone region of interest thermal relaxation and characteristic patterns. LDI was performed with a moorLDI system, and biopsies were captured for histology following the 150-minute imaging session. Both ADT and LDI imaging modalities are able to detect different physical properties at 30, 60, 90 120, and 150 minutes postburn with statistical significance (P < 0.05). Resultant ADT cooling curves characterize greater differences with greater stimulation and a potentially more identifiable differential cooling characteristic. Histological analysis confirmed burn depth. This preliminary work confirms that ADT can measure burn depth and is deserving of further research either as a stand-alone imaging technology or in combination with a device to assess perfusion. PMID:25412050

  7. In situ iron activated persulfate oxidative fluid sparging treatment of TCE contamination--a proof of concept study.

    PubMed

    Liang, Chenju; Lee, I-Ling

    2008-09-10

    In situ chemical oxidation (ISCO) is considered a reliable technology to treat groundwater contaminated with high concentrations of organic contaminants. An ISCO oxidant, persulfate anion (S(2)O(8)(2-)) can be activated by ferrous ion (Fe(2+)) to generate sulfate radicals (E(o)=2.6 V), which are capable of destroying trichloroethylene (TCE). The property of polarity inhibits S(2)O(8)(2-) or sulfate radical (SO(4)(-)) from effectively oxidizing separate phase TCE, a dense non-aqueous phase liquid (DNAPL). Thus the oxidation primarily takes place in the aqueous phase where TCE is dissolved. A bench column study was conducted to demonstrate a conceptual remediation method by flushing either S(2)O(8)(2-) or Fe(2+) through a soil column, where the TCE DNAPL was present, and passing the dissolved mixture through either a Fe(2+) or S(2)O(8)(2-) fluid sparging curtain. Also, the effect of a solubility enhancing chemical, hydroxypropyl-beta-cyclodextrin (HPCD), was tested to evaluate its ability to increase the aqueous TCE concentration. Both flushing arrangements may result in similar TCE degradation efficiencies of 35% to 42% estimated by the ratio of TCE degraded/(TCE degraded+TCE remained in effluent) and degradation byproduct chloride generation rates of 4.9 to 7.6 mg Cl(-) per soil column pore volume. The addition of HPCD did greatly increase the aqueous TCE concentration. However, the TCE degradation efficiency decreased because the TCE degradation was a lower percentage of the relatively greater amount of dissolved TCE by HPCD. This conceptual treatment may serve as a reference for potential on-site application.

  8. Difficult Concepts

    NASA Astrophysics Data System (ADS)

    Fosbury, R.

    2005-12-01

    Beautiful colour images of the sky are both a blessing and a curse for the communication of astronomy to the public. While undoubtedly attractive, they can obscure the fact that discoveries are often made in astrophysics using techniques and measurements that are much more difficult to grasp and certainly less appealing to view. Should we try to explain such concepts as spectroscopy, polarimetry and interferometry, or is it a lost cause? The most effective approach to this problem may be to lead the audience to ask the question themselves: "But how do you know that?"

  9. Communication, concepts and grounding.

    PubMed

    van der Velde, Frank

    2015-02-01

    This article discusses the relation between communication and conceptual grounding. In the brain, neurons, circuits and brain areas are involved in the representation of a concept, grounding it in perception and action. In terms of grounding we can distinguish between communication within the brain and communication between humans or between humans and machines. In the first form of communication, a concept is activated by sensory input. Due to grounding, the information provided by this communication is not just determined by the sensory input but also by the outgoing connection structure of the conceptual representation, which is based on previous experiences and actions. The second form of communication, that between humans or between humans and machines, is influenced by the first form. In particular, a more successful interpersonal communication might require forms of situated cognition and interaction in which the entire representations of grounded concepts are involved.

  10. Space vehicle concepts

    NASA Technical Reports Server (NTRS)

    Tucker, Michael; Meredith, Oliver; Brothers, Bobby

    1986-01-01

    Several concepts of chemical-propulsion Space Vehicles (SVs) for manned Mars landing missions are presented. For vehicle sizing purposes, several specific missions were chosen from opportunities in the late 1990's and early 2000's, and a vehicle system concept is then described which is applicable to the full range of missions and opportunities available. In general, missions utilizing planetary opposition alignments can be done with smaller vehicles than those utilizing planetary opposition alignments. The conjunction missions have a total mission time of about 3 years, including a required stay-time of about 60 days. Both types of missions might be desirable during a Mars program, the opposition type for early low-risk missions and/or for later unmanned cargo missions, and the conjunction type for more extensive science/exploration missions and/or for Mars base activities. Since the opposition missions appeared to drive the SV size more severely, there were probably more cases examined for them. Some of the concepts presented utilize all-propulsive braking, some utilize and all aerobraking approach, and some are hybrids. Weight statements are provided for various cases. Most of the work was done on 0-g vehicle concepts, but partial-g and 1-g concepts are also provided and discussed. Several options for habitable elements are shown, such as large-diameter modules and space station (SS) types of modules.

  11. Creating Heliophysics Concept Maps

    NASA Astrophysics Data System (ADS)

    Ali, N. A.; Peticolas, L. M.; Paglierani, R.; Mendez, B. J.

    2011-12-01

    The Center for Science Education at University of California Berkeley's Space Sciences Laboratory is creating concept maps for Heliophysics and would like to get input from scientists. The purpose of this effort is to identify key concepts related to Heliophysics and map their progression to show how students' understanding of Heliophysics might develop from Kindergarten through higher education. These maps are meant to tie into the AAAS Project 2061 Benchmarks for Scientific Literacy and National Science Education Standards. It is hoped that the results of this effort will be useful for curriculum designers developing Heliophysics-related curriculum materials and classroom teachers using Heliophysics materials. The need for concept maps was identified as a result of product analysis undertaken by the NASA Heliophysics Forum Team. The NASA Science Education and Public Outreach Forums have as two of their goals to improve the characterization of the contents of the Science Mission Directorate and Public Outreach (SMD E/PO) portfolio (Objective 2.1) and assist SMD in addressing gaps in the portfolio of SMD E/PO products and project activities (Objective 2.2). An important part of this effort is receiving feedback from solar scientists regarding the inclusion of key concepts and their progression in the maps. This session will introduce the draft concept maps and elicit feedback from scientists.

  12. Inhaled corticosteroids do not reduce initial high activity of matrix metalloproteinase (MMP)-9 in exhaled breath condensates of children with asthma exacerbation: a proof of concept study.

    PubMed

    Grzela, Katarzyna; Zagórska, Wioletta; Krejner, Alicja; Banaszkiewicz, Aleksandra; Litwiniuk, Małgorzata; Kulus, Marek; Grzela, Tomasz

    2016-01-01

    Inhaled corticosteroids (ICS) are the key component of asthma treatment. However, it is unclear whether they could control the activity and level of matrix metalloproteinase (MMP)-9, which is an important factor in asthma-associated inflammation and airway remodeling. Therefore, the aim of this proof of concept study was to analyze the influence of increased doses of ICS on MMP-9 in exhaled breath condensates (EBC) of patients with allergic asthma exacerbation. Apart from MMP-9, the assessment concerned selected inflammation markers - exhaled nitric oxide (eNO) and cytokines (IL-8 and TNF). The study involved a small group (n = 4) of individuals with asthma exacerbation. The intervention concerned increased doses of ICS with β-mimetics for 4 weeks. In addition to clinical evaluation, eNO measurements and EBC collections were done before and after 4 weeks of intense ICS treatment. The biochemical assessment of EBC concerned MMP-9, IL-8 and TNF. The data were compared to results of healthy controls (n = 6). The initial levels of eNO, MMP-9 and TNF in EBC were higher in the asthma group than in controls. In all subjects IL-8 levels were below the detection limit. After 4 weeks of ICS treatment in all patients we observed improvement of clinical and laboratory parameters. Interestingly, despite reduction of eNO and TNF, the activity of MMP-9/EBC remained on the initial level. Practical relevance of our results is limited by a small group. Nevertheless, our data suggest that ICS, although sufficient to control symptoms and inflammatory markers, may be ineffective to reduce MMP-9/EBC activity in asthma exacerbation and, possibly, airway remodeling. PMID:27536209

  13. Inhaled corticosteroids do not reduce initial high activity of matrix metalloproteinase (MMP)-9 in exhaled breath condensates of children with asthma exacerbation: a proof of concept study

    PubMed Central

    Grzela, Katarzyna; Zagórska, Wioletta; Krejner, Alicja; Banaszkiewicz, Aleksandra; Litwiniuk, Małgorzata; Kulus, Marek

    2016-01-01

    Inhaled corticosteroids (ICS) are the key component of asthma treatment. However, it is unclear whether they could control the activity and level of matrix metalloproteinase (MMP)-9, which is an important factor in asthma-associated inflammation and airway remodeling. Therefore, the aim of this proof of concept study was to analyze the influence of increased doses of ICS on MMP-9 in exhaled breath condensates (EBC) of patients with allergic asthma exacerbation. Apart from MMP-9, the assessment concerned selected inflammation markers – exhaled nitric oxide (eNO) and cytokines (IL-8 and TNF). The study involved a small group (n = 4) of individuals with asthma exacerbation. The intervention concerned increased doses of ICS with β-mimetics for 4 weeks. In addition to clinical evaluation, eNO measurements and EBC collections were done before and after 4 weeks of intense ICS treatment. The biochemical assessment of EBC concerned MMP-9, IL-8 and TNF. The data were compared to results of healthy controls (n = 6). The initial levels of eNO, MMP-9 and TNF in EBC were higher in the asthma group than in controls. In all subjects IL-8 levels were below the detection limit. After 4 weeks of ICS treatment in all patients we observed improvement of clinical and laboratory parameters. Interestingly, despite reduction of eNO and TNF, the activity of MMP-9/EBC remained on the initial level. Practical relevance of our results is limited by a small group. Nevertheless, our data suggest that ICS, although sufficient to control symptoms and inflammatory markers, may be ineffective to reduce MMP-9/EBC activity in asthma exacerbation and, possibly, airway remodeling. PMID:27536209

  14. Teaching Depth of Field Concept

    ERIC Educational Resources Information Center

    Ross, Frederick C.; Smith, Rodney J.

    1978-01-01

    This activity utilizes an overhead projector, a wax pencil, and a petri-dish to demonstrate the depth of field concept to students learning the use of the microscope. Illustrations and directions are included. (MA)

  15. Mini Review: Anticholinergic Activity as a Behavioral Pathology of Lewy Body Disease and Proposal of the Concept of “Anticholinergic Spectrum Disorders”

    PubMed Central

    Tomioka, Hiroi; Hachisu, Mitsugu

    2016-01-01

    Given the relationship between anticholinergic activity (AA) and Alzheimer's disease (AD), we rereview our hypothesis of the endogenous appearance of AA in AD. Briefly, because acetylcholine (ACh) regulates not only cognitive function but also the inflammatory system, when ACh downregulation reaches a critical level, inflammation increases, triggering the appearance of cytokines with AA. Moreover, based on a case report of a patient with mild AD and slightly deteriorated ACh, we also speculate that AA can appear endogenously in Lewy body disease due to the dual action of the downregulation of ACh and hyperactivity of the hypothalamic-pituitary-adrenal axis. Based on these hypotheses, we consider AA to be a behavioral pathology of Lewy body disease. We also propose the concept of “anticholinergic spectrum disorders,” which encompass a variety of conditions, including AD, Lewy body disease, and delirium. Finally, we suggest the prescription of cholinesterase inhibitors to patients in this spectrum of disorders to abolish AA by upregulating ACh. PMID:27738546

  16. Technium concept

    NASA Astrophysics Data System (ADS)

    Clement, Marc; Davies, Stephen

    2002-05-01

    Traditionally the economy of Wales has been based on the coal and steel industries. Recently, Wales has elected its own National Assembly and together with the Welsh Development Agency (WDA) and through a Regional Technology Plan, has prioritized the creation and development of a knowledge based economy. The culture of Wales has always placed emphasis on education and for a small nation, has a University sector with an excellent reputation for advanced research. The WDA and the University of Wales Swansea came together to establish Technium, which is an unique concept designed to bridge the gap between advanced University research and commercial exploitation. Technium was co-funded by the WDA and the European Regional Development Fund. The project is seen as the first phase of creating a network of sector specific Techniums across the country, all linked via state of the art telecomm-infrastructure to University centers of research excellence. This paper will describe two case studies, both in the Optics/Photonics field, of research centers being established in Technium by blue chip international companies. Those companies having located in Technium specifically because of the links to high quality university research. One company is Agilent Technologies Inc., USA) a global leader in Optoelectronic components. The second company, ICN Pharmaceuticals Inc, design and develop optical devices to be used in conjunction with pharmaceuticals for the treatment of a range of diseases. Working closely with the WDA and the University of Wales Swansea, these and other companies will pursue product development, sponsor postgraduate research and generate intellectual capital that will benefit the company, students and the region alike.

  17. Advanced space propulsion concepts

    NASA Technical Reports Server (NTRS)

    Lapointe, Michael R.

    1993-01-01

    The NASA Lewis Research Center has been actively involved in the evaluation and development of advanced spacecraft propulsion. Recent program elements have included high energy density propellants, electrode less plasma thruster concepts, and low power laser propulsion technology. A robust advanced technology program is necessary to develop new, cost-effective methods of spacecraft propulsion, and to continue to push the boundaries of human knowledge and technology.

  18. Effects of a Question Prompt-Based Concept Mapping Approach on Students' Learning Achievements, Attitudes and 5C Competences in Project-Based Computer Course Activities

    ERIC Educational Resources Information Center

    Wang, Hsiu-Ying; Huang, Iwen; Hwang, Gwo-Jen

    2016-01-01

    Concept mapping has been widely used in various fields to facilitate students' organization of knowledge. Previous studies have, however, pointed out that it is difficult for students to construct concept maps from the abundant searched data without appropriate scaffolding. Thus, researchers have suggested that students could produce high quality…

  19. Brace technology thematic series - The Sforzesco and Sibilla braces, and the SPoRT (Symmetric, Patient oriented, Rigid, Three-dimensional, active) concept

    PubMed Central

    2011-01-01

    Background Bracing is an effective strategy for scoliosis treatment, but there is no consensus on the best type of brace, nor on the way in which it should act on the spine to achieve good correction. The aim of this paper is to present the family of SPoRT (Symmetric, Patient-oriented, Rigid, Three-dimensional, active) braces: Sforzesco (the first introduced), Sibilla and Lapadula. Methods The Sforzesco brace was developed following specific principles of correction. Due to its overall symmetry, the brace provides space over pathological depressions and pushes over elevations. Correction is reached through construction of the envelope, pushes, escapes, stops, and drivers. The real novelty is the drivers, introduced for the first time with the Sforzesco brace; they allow to achieve the main action of the brace: a three-dimensional elongation pushing the spine in a down-up direction. Brace prescription is made plane by plane: frontal (on the "slopes", another novelty of this concept, i.e. the laterally flexed sections of the spine), horizontal, and sagittal. The brace is built modelling the trunk shape obtained either by a plaster cast mould or by CAD-CAM construction. Brace checking is essential, since SPoRT braces are adjustable and customisable according to each individual curve pattern. Treatment time and duration is individually tailored (18-23 hours per day until Risser 3, then gradual reduction). SEAS (Scientific Exercises Approach to Scoliosis) exercises are a key factor to achieve success. Results The Sforzesco brace has shown to be more effective than the Lyon brace (matched case/control), equally effective as the Risser plaster cast (prospective cohort with retrospective controls), more effective than the Risser cast + Lyon brace in treating curves over 45 degrees Cobb (prospective cohort), and is able to improve aesthetic appearance (prospective cohort). Conclusions The SPoRT concept of bracing (three-dimensional elongation pushing in a down-up direction

  20. High-Temperature Smart Structures for Engine Noise Reduction and Performance Enhancement

    NASA Technical Reports Server (NTRS)

    Quackenbush, Todd R.; McKillip, Robert M., Jr.

    2011-01-01

    One of key NASA goals is to develop and integrate noise reduction technology to enable unrestricted air transportation service to all communities. One of the technical priorities of this activity has been to account for and reduce noise via propulsion/airframe interactions, identifying advanced concepts to be integrated with the airframe to mitigate these noise-producing mechanisms. An adaptive geometry chevron using embedded smart structures technology offers the possibility of maximizing engine performance while retaining and possibly enhancing the favorable noise characteristics of current designs. New high-temperature shape memory alloy (HTSMA) materials technology enables the devices to operate in both low-temperature (fan) and high-temperature (core) exhaust flows. Chevron-equipped engines have demonstrated reduced noise in testing and operational use. It is desirable to have the noise benefits of chevrons in takeoff/landing conditions, but have them deployed into a minimum drag position for cruise flight. The central feature of the innovation was building on rapidly maturing HTSMA technology to implement a next-generation aircraft noise mitigation system centered on adaptive chevron flow control surfaces. In general, SMA-actuated devices have the potential to enhance the demonstrated noise reduction effectiveness of chevron systems while eliminating the associated performance penalty. The use of structurally integrated smart devices will minimize the mechanical and subsystem complexity of this implementation. The central innovations of the effort entail the modification of prior chevron designs to include a small cut that relaxes structural stiffness without compromising the desired flow characteristics over the surface; the reorientation of SMA actuation devices to apply forces to deflect the chevron tip, exploiting this relaxed stiffness; and the use of high-temperature SMA (HTSMA) materials to enable operation in the demanding core chevron environment

  1. The Directed Reading-Thinking Activity (DR-TA) and the Traditional Approach Using Tales of Virtue Based on His Majesty the King's Teaching Concepts in Seventh Grade Students' Reading Comprehension

    ERIC Educational Resources Information Center

    Chaemsai, Rungruedee; Rattanavich, Saowalak

    2016-01-01

    This study compares the English reading comprehension and ethical awareness of 7th grade students, when using either a directed reading-thinking activity (DR-TA), or a more traditional approach, involving tales of virtue based on His Majesty the King's teaching concepts. A randomized control group pretest-posttest design was used for the study,…

  2. LES-based evaluation of a microjet noise reduction concept in static and flight conditions

    NASA Astrophysics Data System (ADS)

    Shur, Mikhail L.; Spalart, Philippe R.; Strelets, Mikhail Kh.

    2011-08-01

    The Large-Eddy Simulation (LES) numerical system established since 2002 for jet-noise computation is first evaluated in terms of recent gains in accuracy with increased computer resources, and is then used to explore the relatively new "microjet" noise-reduction concept (injection of high-pressure microjets in the vicinity of the main jet nozzle exit), which currently attracts attention in the aeroacoustic community. The simulations, which are carried out with an emulation of the microjets by specially designed distributed sources of mass, momentum, and energy in the governing equations, are found to capture the essential features of the flow/turbulence and the far-field noise alteration by the microjets observed in experiments, and to reveal the subtle flow features responsible for the effect of injection on noise. They also confirm the experimental observation that in static conditions microjets provide a noise reduction comparable with that from chevrons in the low-frequency range, and probably have a less pronounced high-frequency penalty. This positive evaluation of the microjets concept is, however, mitigated by the far less favorable results of simulations in flight conditions, which were never studied experimentally. The latter results, which are awaiting an experimental verification, make a practical use of the concept in its current form rather unlikely.

  3. Implementation of the beryllium reflector filter concept in the LANSCE 1L target Mark-III upgrade.

    SciTech Connect

    Muhrer, G.; Pitcher, E. J.; Russell, G. J.

    2005-01-01

    We have investigated the possibility of implementing the idea of a beryllium reflector filter in the LANSCE 1L target Mark-III upgrade. We will present different concepts of beryllium reflector filters (megaphone, chevron and swiss-cheese concept) and their effect on the integrated cold flux and the time distribution of the lower tier hydrogen flux-trap moderator as a function of the three instruments, (SPEAR, LQD and Asterix) which are served by this moderator. As part of the LANSCE 1L target upgrade study it is the declared goal to increase the cold flux (E < 5meV) of the lower tier partially coupled liquid hydrogen moderator by a factor of two. This goal is proposed to be achieved by adding a pre-moderator system to the moderator and by implementing the cold beryllium reflector concept. The cold beryllium reflector filter concept was tested in an experiment at the weapons neutron research (WNR) facility at LANSCE in January 2003 by Pitcher et al. Based on the success of this experiment it was then decided to implement this concept into the 1L target Mark-III upgrade. In this context a series of Monte Carlo transport calculations was performed to optimize the cold neutron flux.

  4. San Diego Gas and Electric Company Imperial Valley geothermal activities

    NASA Technical Reports Server (NTRS)

    Hinrichs, T. C.

    1974-01-01

    San Diego Gas and Electric and its wholly owned subsidiary New Albion Resources Co. have been affiliated with Magma Power Company, Magma Energy Inc. and Chevron Oil Company for the last 2-1/2 years in carrying out geothermal research and development in the private lands of the Imperial Valley. The steps undertaken in the program are reviewed and the sequence that must be considered by companies considering geothermal research and development is emphasized. Activities at the south end of the Salton Sea and in the Heber area of Imperial Valley are leading toward development of demonstration facilities within the near future. The current status of the project is reported.

  5. Water laws and concepts

    USGS Publications Warehouse

    Thomas, H.E.

    1970-01-01

    Throughout human history various laws and customs have developed concerning the individual rights and rights in common to the waters of the earth. Many existing laws and concepts are clearly influenced by the environment in which they originated and reflect the relative abundance or scarcity of water. Many concepts reflect the people's original interests in the water and once established have been passed from generation to generation with little modification. Some laws and concepts have been carried by people in their migrations and colonial expansions to vastly different environments, with rather curious consequences. In many places water laws that had been well adapted to the natural environment have become less tenable because of man's activities in modifying that environment, or because of increasing use of water: Increasing consumptive use shifts the water economy toward lesser abundance or increasing deficiency; increasing nonconsumptive use results in pollution of the water resources, so that they become less suitable for other users. The water-rights systems in the United States vary from State to State: some are reasonably fitted to their environment, some have outlived their place in history, some are wasteful of water, some show favoritism to certain special interests or segments of the population. Water-use rights are universally recognized as real property, with constitutional protection against deprivation without due process of law.

  6. The Fuego System Concept

    NASA Astrophysics Data System (ADS)

    Martín-rico, Cristóbal; Gonzalo, Jesús; Mariani, Andrea; Leibrandt, Wolfgang

    FUEGO is a satellite system intended to provide the firefighting forces in the world with early fire warning and fire monitoring capabilities. It is being conceived with the users, by fostering continuous user direction of the development process. This system concept is presented. We present the user requirements that have evolved from user consultation and have been confirmed in the First FUEGO Users Conference in Madrid. The sensor arrangement is discussed including the sort of algorithm envisaged and the necessary supporting spectral bands and sensitivity. Technological aspects are reviewed. The operational concept is briefly described. The architecture is shown to be flexible and adapted to user expectations. From the operational concept the satellite and ground segment requirements and design are presented, to show the feasibility in technical and programmatic terms. The main system issues are analysed for criticality and basic conclusions are derived. A summary of cost benefit analysis is presented. A satellite system is therefore proposed as an operational mission to support the forest firefighting activity.

  7. The concept behind sugammadex.

    PubMed

    Epemolu, O; Bom, A

    2014-05-01

    Sugammadex is the first selective relaxant binding agent. It allows rapid reversal of any degree of neuromuscular blockade induced by steroidal neuromuscular blocking agents. Sugammadex acts by encapsulation of the neuromuscular blocking agent. This prevents the drug from acting on prejunctional and postjunctional nicotinic receptors, allowing acetylcholine to activate these receptors, and resulting in reversal of the neuromuscular blockade. Objective monitoring of the degree of neuromuscular blockade is strongly recommended to determine the optimal dose of sugammadex. A good understanding of the concept behind sugammadex is essential in order to use this reversal agent in clinical practice.

  8. SCIENCE BRIEF: ADVANCED CONCEPTS

    EPA Science Inventory

    Research on advanced concepts will evaluate and demonstrate the application of innovative infrastructure designs, management procedures and operational approaches. Advanced concepts go beyond simple asset management. The infusion of these advanced concepts into established wastew...

  9. [Pleasure: Neurobiological conception and Freudian conception].

    PubMed

    Chenu, A; Tassin, J-P

    2014-04-01

    Despite many controversies the debate between psychoanalysis and neuroscience remains intense, all the more since the Freudian theory stands as a reference for a number of medical practitioners and faculty psychiatrists, at least in France. Instead of going on arguing we think that it may be more constructive to favour dialogue through the analysis of a precise concept developed in each discipline. The Freudian theory of pleasure, because it is based on biological principles, appears an appropriate topic to perform this task. In this paper, we aim at comparing Freud's propositions to those issued from recent findings in Neuroscience. Like all emotions, pleasure is acknowledged as a motivating factor in contemporary models. Pleasure can indeed be either rewarding when it follows satisfaction, or incentive when it reinforces behaviours. The Freudian concept of pleasure is more univocal. In Freud's theory, pleasure is assumed to be the result of the discharge of the accumulated excitation which will thus reduce the tension. This quantitative approach corresponds to the classical scheme that associates satisfaction and pleasure. Satisfaction of a need would induce both a decrease in tension and the development of pleasure. However, clinical contradictions to this model, such as the occasional co-existence between pleasure and excitation, drove Freud to suggest different theoretical reversals. Freud's 1905 publication, which describes how preliminary sexual pleasures contribute to an increased excitation and a sexual satisfaction, is the only analysis which provides an adapted answer to the apparent paradox of pleasure and excitation co-existence. Studies on the neurobiological mechanisms responsible for the development of pleasure may help to fill this gap in the Freudian theory. Activity of the mesolimbic dopaminergic pathway is strongly associated with the reward system. Experimental studies performed in animals have shown that increased dopaminergic activity in the

  10. [Pleasure: Neurobiological conception and Freudian conception].

    PubMed

    Chenu, A; Tassin, J-P

    2014-04-01

    Despite many controversies the debate between psychoanalysis and neuroscience remains intense, all the more since the Freudian theory stands as a reference for a number of medical practitioners and faculty psychiatrists, at least in France. Instead of going on arguing we think that it may be more constructive to favour dialogue through the analysis of a precise concept developed in each discipline. The Freudian theory of pleasure, because it is based on biological principles, appears an appropriate topic to perform this task. In this paper, we aim at comparing Freud's propositions to those issued from recent findings in Neuroscience. Like all emotions, pleasure is acknowledged as a motivating factor in contemporary models. Pleasure can indeed be either rewarding when it follows satisfaction, or incentive when it reinforces behaviours. The Freudian concept of pleasure is more univocal. In Freud's theory, pleasure is assumed to be the result of the discharge of the accumulated excitation which will thus reduce the tension. This quantitative approach corresponds to the classical scheme that associates satisfaction and pleasure. Satisfaction of a need would induce both a decrease in tension and the development of pleasure. However, clinical contradictions to this model, such as the occasional co-existence between pleasure and excitation, drove Freud to suggest different theoretical reversals. Freud's 1905 publication, which describes how preliminary sexual pleasures contribute to an increased excitation and a sexual satisfaction, is the only analysis which provides an adapted answer to the apparent paradox of pleasure and excitation co-existence. Studies on the neurobiological mechanisms responsible for the development of pleasure may help to fill this gap in the Freudian theory. Activity of the mesolimbic dopaminergic pathway is strongly associated with the reward system. Experimental studies performed in animals have shown that increased dopaminergic activity in the

  11. Fundamental Research in Engineering Education. Development of Concept Questions and Inquiry-Based Activities in Thermodynamics and Heat Transfer: An Example for Equilibrium vs. Steady-State

    ERIC Educational Resources Information Center

    Vigeant, Margot; Prince, Michael; Nottis, Katharyn

    2011-01-01

    This study examines the use of inquiry-based instruction to promote the understanding of critical concepts in thermodynamics and heat transfer. Significant research shows that students frequently enter our courses with tightly held misconceptions about the physical world that are not effectively addressed through traditional instruction. Students'…

  12. Conceptions of Parents, Conceptions of Self, and Conceptions of God.

    ERIC Educational Resources Information Center

    Buri, John R.; Mueller, Rebecca A.

    Different theorists have suggested that an individual's view of God may be related to one's view of one's father, one's mother, or one's self. A study was conducted to examine the relationship of college students' conceptions of the wrathfulness-kindliness of God to their conceptions of their father's and mother's permissiveness, authoritarianism,…

  13. Confirmatory Survey Report for Area B1S/B2S at the Chevron Mining Washington Remediation Project, Washington, PA

    SciTech Connect

    W. C. Adams

    2007-11-20

    During the period of October 2 and 3, 2007, the Oak Ridge Institute for Science and Education (ORISE) performed confirmatory radiological survey activities which included gamma surface scans within Area B1S/B2S and the collection of soil samples from these areas.

  14. Putting concepts into context.

    PubMed

    Yee, Eiling; Thompson-Schill, Sharon L

    2016-08-01

    At first glance, conceptual representations (e.g., our internal notion of the object "lemon") seem static; we have the impression that there is something that the concept lemon "means" (a sour, yellow, football-shaped citrus fruit) and that this meaning does not vary. Research in semantic memory has traditionally taken this "static" perspective. Consequently, only effects demonstrated across a variety of contexts have typically been considered informative regarding the architecture of the semantic system. In this review, we take the opposite approach: We review instances of context-dependent conceptual activation at many different timescales-from long-term experience, to recent experience, to the current task goals, to the unfolding process of conceptual activation itself-and suggest that the pervasive effects of context across all of these timescales indicate that rather than being static, conceptual representations are constantly changing and are inextricably linked to their contexts. PMID:27282993

  15. Concepts in Change

    ERIC Educational Resources Information Center

    Rusanen, Anna-Mari; Poyhonen, Samuli

    2013-01-01

    In this article we focus on the concept of concept in conceptual change. We argue that (1) theories of higher learning must often employ two different notions of concept that should not be conflated: psychological and scientific concepts. The usages for these two notions are partly distinct and thus straightforward identification between them is…

  16. The Moon Village Concept

    NASA Astrophysics Data System (ADS)

    Messina, Piero; Foing, Bernard H.; Hufenbach, Bernhard; Haignere, Claudie; Schrogl, Kai-Uwe

    2016-07-01

    The "Moon Village" concept Space exploration is anchored in the International Space Station and in the current and future automatic and planetary automatic and robotic missions that pave the way for future long-term exploration objectives. The Moon represents a prime choice for scientific, operational and programmatic reasons and could be the enterprise that federates all interested Nations. On these considerations ESA is currently elaborating the concept of a Moon Village as an ensemble where multiple users can carry out multiple activities. The Moon Village has the ambition to serve a number of objectives that have proven to be of interest (including astronomy, fundamental research, resources management, moon science, etc. ) to the space community and should be the catalyst of new alliances between public and private entities including non-space industries. Additionally the Moon Village should provide a strong inspirational and education tool for the younger generations . The Moon Village will rely both on automatic, robotic and human-tendered structures to achieve sustainable moon surface operations serving multiple purposes on an open-architecture basis. This Europe-inspired initiative should rally all communities (across scientific disciplines, nations, industries) and make it to the top of the political agendas as a the scientific and technological undertaking but also political and inspirational endeavour of the XXI century. The current reflections are of course based on the current activities and plans on board the ISS and the discussion held in international fora such as the ISECG. The paper will present the status of these reflections, also in view of the ESA Council at Ministerial Level 2016, and will give an overview of the on-going activities being carried out to enable the vision of a Moon Village.

  17. Using Online Concept Mapping with Peer Learning to Enhance Concept Application

    ERIC Educational Resources Information Center

    Chang, Shujen L.; Chang, Yegmin

    2008-01-01

    This study used an online concept mapping activity (CMA) featuring peer learning to enhance learning achievement in concept application. Ninety-seven graduate students participated in this study. The students who participated in the online CMA could later apply the concepts with significantly higher performance and greater fidelity than those who…

  18. What's in a Word? Concept mapping: a graphical tool to reinforce learning of epidemiological concepts.

    PubMed

    Berglund, Anita

    2015-12-01

    Epidemiology is founded on central concepts and principles, essential for conducting, reporting and critically assessing epidemiological studies. Definitions of the many concepts used in the field can be found in textbooks and via the Dictionary of Epidemiology. However, central epidemiological concepts are labelled and used in multiple ways, leading to potential misunderstanding when communicating in different fora. The aim here is to describe collaborative concept mapping, and illustrate how it can be used in teaching and learning epidemiology. Concept mapping is a cognitive technique that is widely used in the education of medical and allied health professions as a tool for critical thinking, and to assimilate new knowledge, but it is still under-utilised in epidemiology. A specific concept map is defined by the aim and question in focus; it is thus framed by a context. The concept map is constructed using a set of concepts (nodes) that are linked with arrows or lines (links). Words and phrases (connective terms) are used to explain relationships between the concepts linked. Different domains can be interconnected by linking concepts in different areas (cross-links). The underlying structure of knowledge is often complex, and consequently concept maps can be constructed using different topological features. Here we provide an illustrative example of concept mapping, based on a set of 'basic' concepts introduced in a doctoral course in epidemiology. In summary, concept mapping is a compelling, active learning tool, which can promote shared deeper knowledge of concepts and their complex interconnections, thereby facilitating a better understanding of epidemiological research.

  19. Threshold Concepts and Pedagogic Representation

    ERIC Educational Resources Information Center

    Meyer, Jan H. F.

    2016-01-01

    Purpose: The purpose of this paper is to present a brief exposure to the development of the threshold concepts framework (TCF), the intention being to illuminate for interested readers a broader landscape of research activity than that perhaps conveyed by the individual contributions to this special edition. Design/Methodology/Approach: There is…

  20. Space Station medical sciences concepts

    NASA Technical Reports Server (NTRS)

    Mason, J. A. (Editor); Johnson, P. C., Jr. (Editor)

    1984-01-01

    Current life sciences concepts relating to Space Station are presented including the following: research, extravehicular activity, biobehavioral considerations, medical care, maintenance of dental health, maintaining health through physical conditioning and countermeasures, protection from radiation, atmospheric contamination control, atmospheric composition, noise pollution, food supply and service, clothing and furnishings, and educational program possibilities. Information on the current status of Soviet Space Stations is contained.

  1. Investigating the Ocean-Climate System, Concept by Concept

    NASA Astrophysics Data System (ADS)

    Decharon, A.; Karp-Boss, L.; Boss, E.; Graham, S.; Manahan, A.; Weller, H.

    2006-12-01

    In fall 2005, a new initiative was added to the Centers for Ocean Sciences Education Excellence (COSEE) Network. COSEE-Ocean Systems (OS) is a collaborative effort among the University of Maine (UMaine), University of New Hampshire, and Bigelow Laboratory for Ocean Sciences. Being thematic in nature, COSEE-OS has the flexibility to tackle topics that are important on the national scale, such as those highlighted in the recent "Ocean Literacy" campaign. COSEE-OS has the long-term goal of helping COSEE reach rural and inland audiences. We are creating and evaluating a series of interconnected tools and techniques to broaden understanding of oceans in the context of the earth and solar systems. This includes: - Building and training scientist-educator teams who work together to distinguish meaningful "key messages" and the K-12 audiences who would benefit most from exposure to these concepts; - Translating the concepts into innovative products, workshops, and courses that showcase oceans in the Earth-Sun system; - Working with NASA multimedia experts, developing immersive web-based interfaces that will be utilized by and / or customized for other COSEEs; and - Training in-service and pre-service teachers in using ocean phenomena as a vehicle to teach physical concepts using hands-on activities and inquiry based learning. Part of the COSEE-OS strategy is engaging teams with an educational tool called "concept mapping." Dr. Joseph Novak developed concept mapping in the 1960s as a technique for representing knowledge in graphical formats. Used as a group activity this allows COSEE-OS to gather vital information from scientists to construct multimedia products. Another benefit of this activity is helping scientists and educators test the utility of concept mapping for their instructional purposes. To complement the development of concept maps and associated multimedia, a UMaine COSEE-OS pilot workshop was held in July 2006. The workshop targeted middle- and high

  2. Race concepts in medicine.

    PubMed

    Hardimon, Michael O

    2013-02-01

    Confusions about the place of race in medicine result in part from a failure to recognize the plurality of race concepts. Recognition that the ordinary concept of race is not identical to the racialist concept of race makes it possible to ask whether there might be a legitimate place for the deployment of concepts of race in medical contexts. Two technical race concepts are considered. The concept of social race is the concept of a social group that is taken to be a racialist race. It is apt for use in examining and addressing the medical effects of discrimination. The populationist concept of race represents race as a kind of biological population. It makes it possible to frame the question whether biological race is a factor in disease susceptibility and drug responsiveness. It is apt for use in determining whether biological race is a medically significant category.

  3. The semantic richness of abstract concepts

    PubMed Central

    Recchia, Gabriel; Jones, Michael N.

    2012-01-01

    We contrasted the predictive power of three measures of semantic richness—number of features (NFs), contextual dispersion (CD), and a novel measure of number of semantic neighbors (NSN)—for a large set of concrete and abstract concepts on lexical decision and naming tasks. NSN (but not NF) facilitated processing for abstract concepts, while NF (but not NSN) facilitated processing for the most concrete concepts, consistent with claims that linguistic information is more relevant for abstract concepts in early processing. Additionally, converging evidence from two datasets suggests that when NSN and CD are controlled for, the features that most facilitate processing are those associated with a concept's physical characteristics and real-world contexts. These results suggest that rich linguistic contexts (many semantic neighbors) facilitate early activation of abstract concepts, whereas concrete concepts benefit more from rich physical contexts (many associated objects and locations). PMID:23205008

  4. Advanced propulsion concepts

    NASA Technical Reports Server (NTRS)

    Frisbee, Robert H.

    1991-01-01

    A variety of Advanced Propulsion Concepts (APC) is discussed. The focus is on those concepts that are sufficiently near-term that they could be developed for the Space Exploration Initiative. High-power (multi-megawatt) electric propulsion, solar sails, tethers, and extraterrestrial resource utilization concepts are discussed. A summary of these concepts and some general conclusions on their technology development needs are presented.

  5. Anhedonia: A Concept Analysis

    PubMed Central

    Ho, Nancy; Sommers, Marilyn

    2013-01-01

    Anhedonia presents itself in a myriad of disease processes. To further develop our understanding of anhedonia and effective ways to manage it, the concept requires clear boundaries. This paper critically examined the current scientific literature and conducted a concept analysis of anhedonia to provide a more accurate and lucid understanding the concept. As part of the concept analysis, this paper also provides model, borderline, related, and contrary examples of anhedonia. PMID:23706888

  6. Using the Concept of Zone of Proximal Development to Explore the Challenges of and Opportunities in Designing Discourse Activities Based on Practical Work

    ERIC Educational Resources Information Center

    Mestad, Idar; Kolstø, Stein Dankert

    2014-01-01

    This article reports a study in which two researchers collaborated with five teachers to facilitate discourse activities aimed to enhance students' learning from practical activities. The paper explores how certain teacher practices support or hinder students' learning. Four cases from the study were analyzed in depth using…

  7. The Effects of Teaching Numerical Control Concepts Via Simulator Versus Non-Simulator Activities on the Achievement, Programming Proficiency and Attitude of High School Students.

    ERIC Educational Resources Information Center

    Pine, Douglas Taylor

    This study utilized 120 metalworking students and six teachers from Columbus, Ohio area high schools to ascertain the effects of teaching numerical control to industrial arts students by means of simulator-aided activities versus nonsimulator aided activities. Scores obtained from an achievement test, attitude inventory, and word address…

  8. The Influence of an Activity-Based Explicit Approach on the Turkish Prospective Science Teachers' Conceptions of the Nature of Science

    ERIC Educational Resources Information Center

    Celik, Suat; Bayrakceken, Samih

    2012-01-01

    The aim of this study was to investigate the effect of an activity-based explicit nature of science (NOS) instruction undertaken in the context of a "Science, Technology and Society" course on the prospective science teachers' (PSTs') understandings of NOS. In this course, social science based inquiry activities were used to as a context to lead…

  9. Accelerated development and flight evaluation of active controls concepts for subsonic transport aircraft. Volume 1: Load alleviation/extended span development and flight tests

    NASA Technical Reports Server (NTRS)

    Johnston, J. F.

    1979-01-01

    Active wing load alleviation to extend the wing span by 5.8 percent, giving a 3 percent reduction in cruise drag is covered. The active wing load alleviation used symmetric motions of the outboard ailerons for maneuver load control (MLC) and elastic mode suppression (EMS), and stabilizer motions for gust load alleviation (GLA). Slow maneuvers verified the MLC, and open and closed-loop flight frequency response tests verified the aircraft dynamic response to symmetric aileron and stabilizer drives as well as the active system performance. Flight tests in turbulence verified the effectiveness of the active controls in reducing gust-induced wing loads. It is concluded that active wing load alleviation/extended span is proven in the L-1011 and is ready for application to airline service; it is a very practical way to obtain the increased efficiency of a higher aspect ratio wing with minimum structural impact.

  10. Threshold Concepts in Biochemistry

    ERIC Educational Resources Information Center

    Loertscher, Jennifer

    2011-01-01

    Threshold concepts can be identified for any discipline and provide a framework for linking student learning to curricular design. Threshold concepts represent a transformed understanding of a discipline, without which the learner cannot progress and are therefore pivotal in learning in a discipline. Although threshold concepts have been…

  11. Applications of Concept Mapping

    ERIC Educational Resources Information Center

    De Simone, Christina

    2007-01-01

    This article reviews three major uses of the concept-mapping strategies for postsecondary learning: the external representation of concept maps as an external scratch pad to represent major ideas and their organization, the mental construction of concept maps when students are seeking a time-efficient tool, and the electronic construction and…

  12. Online Exhibits & Concept Maps

    NASA Astrophysics Data System (ADS)

    Douma, M.

    2009-12-01

    Presenting the complexity of geosciences to the public via the Internet poses a number of challenges. For example, utilizing various - and sometimes redundant - Web 2.0 tools can quickly devour limited time. Do you tweet? Do you write press releases? Do you create an exhibit or concept map? The presentation will provide participants with a context for utilizing Web 2.0 tools by briefly highlighting methods of online scientific communication across several dimensions. It will address issues of: * breadth and depth (e.g. from narrow topics to well-rounded views), * presentation methods (e.g. from text to multimedia, from momentary to enduring), * sources and audiences (e.g. for experts or for the public, content developed by producers to that developed by users), * content display (e.g. from linear to non-linear, from instructive to entertaining), * barriers to entry (e.g. from an incumbent advantage to neophyte accessible, from amateur to professional), * cost and reach (e.g. from cheap to expensive), and * impact (e.g. the amount learned, from anonymity to brand awareness). Against this backdrop, the presentation will provide an overview of two methods of online information dissemination, exhibits and concept maps, using the WebExhibits online museum (www.webexhibits.org) and SpicyNodes information visualization tool (www.spicynodes.org) as examples, with tips on how geoscientists can use either to communicate their science. Richly interactive online exhibits can serve to engage a large audience, appeal to visitors with multiple learning styles, prompt exploration and discovery, and present a topic’s breadth and depth. WebExhibits, which was among the first online museums, delivers interactive information, virtual experiments, and hands-on activities to the public. While large, multidisciplinary exhibits on topics like “Color Vision and Art” or “Calendars Through the Ages” require teams of scholars, user interface experts, professional writers and editors

  13. The physical self in motion: within-person change and associations of change in self-esteem, physical self-concept, and physical activity in adolescent girls.

    PubMed

    Lindwall, Magnus; Asci, Hulya; Crocker, Peter

    2014-12-01

    The purpose of this study was to examine patterns of within-person change, and associations of change, in global self-esteem (GSE), physical self-perceptions (PSP), and physical activity in a sample of 705 Canadian adolescent girls over three measurements points and 24 months. The Physical Self-Perceptions Profile (PSPP) was used to measure GSE and PSP, and the Physical Activity Questionnaire for Adolescents (PAQ-A) was used to assess physical activity. Latent growth curve models were used to analyze the data. All PSP variables except for body attractiveness demonstrated significant average decline, but also significant was the change in between-person heterogeneity. Change in GSE and PSP was moderately to strongly related on a between-person level and weakly to moderately associated on a within-person level. Change in physical activity was related to change in the majority of the PSP variables but not to change in GSE.

  14. The physical self in motion: within-person change and associations of change in self-esteem, physical self-concept, and physical activity in adolescent girls.

    PubMed

    Lindwall, Magnus; Asci, Hulya; Crocker, Peter

    2014-12-01

    The purpose of this study was to examine patterns of within-person change, and associations of change, in global self-esteem (GSE), physical self-perceptions (PSP), and physical activity in a sample of 705 Canadian adolescent girls over three measurements points and 24 months. The Physical Self-Perceptions Profile (PSPP) was used to measure GSE and PSP, and the Physical Activity Questionnaire for Adolescents (PAQ-A) was used to assess physical activity. Latent growth curve models were used to analyze the data. All PSP variables except for body attractiveness demonstrated significant average decline, but also significant was the change in between-person heterogeneity. Change in GSE and PSP was moderately to strongly related on a between-person level and weakly to moderately associated on a within-person level. Change in physical activity was related to change in the majority of the PSP variables but not to change in GSE. PMID:25602138

  15. Basic concepts of epigenetics

    PubMed Central

    Mazzio, Elizabeth A

    2012-01-01

    Through epigenetic modifications, specific long-term phenotypic consequences can arise from environmental influence on slowly evolving genomic DNA. Heritable epigenetic information regulates nucleosomal arrangement around DNA and determines patterns of gene silencing or active transcription. One of the greatest challenges in the study of epigenetics as it relates to disease is the enormous diversity of proteins, histone modifications and DNA methylation patterns associated with each unique maladaptive phenotype. This is further complicated by a limitless combination of environmental cues that could alter the epigenome of specific cell types, tissues, organs and systems. In addition, complexities arise from the interpretation of studies describing analogous but not identical processes in flies, plants, worms, yeast, ciliated protozoans, tumor cells and mammals. This review integrates fundamental basic concepts of epigenetics with specific focus on how the epigenetic machinery interacts and operates in continuity to silence or activate gene expression. Topics covered include the connection between DNA methylation, methyl-CpG-binding proteins, transcriptional repression complexes, histone residues, histone modifications that mediate gene repression or relaxation, histone core variant stability, H1 histone linker flexibility, FACT complex, nucleosomal remodeling complexes, HP1 and nuclear lamins. PMID:22395460

  16. Comfort measures: a concept analysis.

    PubMed

    Oliveira, Irene

    2013-01-01

    Reference to the concept of comfort measures is growing in the nursing and medical literature; however, the concept of comfort measures is rarely defined. For the comfort work of nurses to be recognized, nurses must be able to identify and delineate the key attributes of comfort measures. A concept analysis using Rodgers' evolutionary method (2000) was undertaken with the goal of identifying the core attributes of comfort measures and thereby clarifying this concept. Health care literature was accessed from the CINAHL and PubMed databases. No restrictions were placed on publication dates. Four main themes of attributes for comfort measures were identified during the analysis. Comfort measures involve an active, strategic process including elements of "stepping in" and "stepping back," are both simple and complex, move from a physical to a holistic perspective and are a part of supportive care. The antecedents to comfort measures are comfort needs and the most common consequence of comfort measures is enhanced comfort. Although the concept of comfort measures is often associated with end-of-life care, this analysis suggests that comfort measures are appropriate for nursing care in all settings and should be increasingly considered in the clinical management of patients who are living with multiple, chronic comorbidities.

  17. On the use of the activation energy concept to investigate analyte and network deformations in entangled polymer solution capillary electrophoresis of synthetic polyelectrolytes.

    PubMed

    Cottet, H; Gareil, P

    2001-01-01

    The activation energy associated with the electrophoretic migration of an analyte under given electrolyte conditions can be accessed through the determination of the analyte electrophoretic mobility at various temperatures. In the case of the electrophoretic separation of polyelectrolytes in the presence of an entangled polymer network, activation energy can be regarded as the energy needed by the analyte to overcome the obstacles created by the separating network. Any deformation undergone by the analyte or the network is expected to induce a decrease in the activation energy. In this work, the electrophoretic mobilities of poly(styrenesulfonates) (PSSs) of various molecular weights (Mr 16 x 10(3) to 990 x 10(3)) were determined in entangled polyethylene oxide (PEO) solutions as a function of temperature (in the 17-60 degrees C range) and the PSS activation energies were calculated. The influences of the PSS molecular weight, blob sizes zetab of the separating network (related to the PEO concentration), ionic strength of the electrolyte and electric field strength (75-600 V/cm) were investigated. The results were interpreted in terms of analyte and network deformations and were confronted with those previously obtained for DNA migration in polymer solutions and chemical gels. For a radius of gyration Rgactivation energy increases with the PSS molecular mass, while the reverse is true for Rg>zetab, suggesting PSS and network deformations in the latter case. Increasing ionic strength resulted in an increase in the PSS activation energy, because of the decrease of their radii of gyration, which makes them less deformable. Finally, the activation energies of all the PSSs are a decreasing function of field strength and at high field strength tend to reach a constant value close to that for a small molecule.

  18. Teaching Striking/Fielding Concepts in Cricket

    ERIC Educational Resources Information Center

    Turner, Adrian P.

    2004-01-01

    This article presents activities for developing striking/fielding concepts in modified cricket games. Though not as familiar to American children, cricket is emerging as the second (to soccer) most popular game in the world. The novelty of the skills provides an appropriate learning challenge for all students while reinforcing concepts and…

  19. Developing Self-Concept through Media.

    ERIC Educational Resources Information Center

    Dorn, Fred

    1980-01-01

    Determined the effects of the Self-Incorporated Program on student self-concept. One group was exposed to the program while another group participated in regular classroom activities. Results indicated a significant difference between groups on the overall self-concept score, but not on comparisons of sub-scale scores. (Author/BEF)

  20. Improved Self-Concepts Through Visual Communication.

    ERIC Educational Resources Information Center

    Gill, Walter Arthur

    Investigations linking communication media experiences and self-concepts suggest that changes in the self-concept of Afro-American students may be acutely affected in instructional environments through group activities employing mediated approaches, participation in the media as producers rather than consumers, and instruction through visual…

  1. A Cross-Sectional Survey Study About the Most Common Solitary and Social Flow Activities to Extend the Concept of Optimal Experience

    PubMed Central

    Magyaródi, Tímea; Oláh, Attila

    2015-01-01

    Previous assumptions note that the most powerful experiences of engagement are shared with others. Therefore, in the framework of positive psychology, to expand the dynamic interactionism-related flow theory, we have attempted to conduct an exploratory study about flow to reveal the most common activities that can trigger this experience during solitary or social situations. The study involved 1,709 adult participants from Hungary (Age: M = 26.95, SD = 11.23). They read descriptions about optimal experience in solitary and social situations and were asked to identify the activity from their life that is most typically followed by the described experiences. The social context was supplemented by other flow-related questions for a deeper understanding and to contribute to the research. According to the results the most typical solitary flow activities are found to be work, sports, creative activities and reading. The most common flow-inducing social activities are work and sports. The choice of the most frequent flow-inducing activities in both solitary and interpersonal situations is dependent on the gender of the respondent, and various demographical factors can influence the frequency of flow experiences in different contexts. Analysis reveal that optimal experience during a social interaction is determined by the perceived level of challenges, the perceived level of cooperation, the immediateness and clarity of the feedback, and the level of the skill. Our study may contribute to the broadening purpose of positive psychology as it focuses on the interpersonal level in relation to flow experience, which, in turn, may also support a higher level of well-being. PMID:27247682

  2. Defining torpor in free-ranging bats: experimental evaluation of external temperature-sensitive radiotransmitters and the concept of active temperature.

    PubMed

    Willis, C K R; Brigham, R M

    2003-07-01

    A variety of definitions involving body temperature (Tb), metabolic rate and behavior have been used to define torpor in mammals and birds. This problem is confounded in some studies of free-ranging animals that employ only skin temperature (Tsk), a measure that approximates but may not precisely reflect Tb. We assess the accuracy of Tsk in the context of a recent definition for torpor called active temperature. We compared the active temperatures of individual big brown bats (Eptesicus fuscus), which aggregate in cavities, with solitary, foliage-roosting hoary bats (Lasiurus cinereus). In captive big brown bats, we compared Tsk and core Tb at a range of ambient temperatures for clustered and solitary roosting animals, compared Tsk and Tb during arousal from torpor, and quantified the effect of flight on warming from torpor. Hoary bats had significantly lower active temperatures than big brown bats despite having the same normothermic Tsk. Tsk was significantly lower than Tb during normothermia but often greater than Tb during torpor. Flight increased the rate of warming from torpor. This effect was more pronounced for Tsk than Tb. This suggests that bats could rely on heat generated by flight muscles to complete the final stages of arousal. Using active temperature to define torpor may underestimate torpor due to ambient cooling of external transmitters or animals leaving roosts while still torpid. Conversely, active temperature may also overestimate shallow torpor use if it is recorded during active arousal when shivering and non-shivering thermogenesis warm external transmitters. Our findings illuminate the need for laboratory studies that quantify the relationship between metabolic rate and Tsk over a range of ambient temperatures. PMID:12764630

  3. A Cross-Sectional Survey Study About the Most Common Solitary and Social Flow Activities to Extend the Concept of Optimal Experience.

    PubMed

    Magyaródi, Tímea; Oláh, Attila

    2015-11-01

    Previous assumptions note that the most powerful experiences of engagement are shared with others. Therefore, in the framework of positive psychology, to expand the dynamic interactionism-related flow theory, we have attempted to conduct an exploratory study about flow to reveal the most common activities that can trigger this experience during solitary or social situations. The study involved 1,709 adult participants from Hungary (Age: M = 26.95, SD = 11.23). They read descriptions about optimal experience in solitary and social situations and were asked to identify the activity from their life that is most typically followed by the described experiences. The social context was supplemented by other flow-related questions for a deeper understanding and to contribute to the research. According to the results the most typical solitary flow activities are found to be work, sports, creative activities and reading. The most common flow-inducing social activities are work and sports. The choice of the most frequent flow-inducing activities in both solitary and interpersonal situations is dependent on the gender of the respondent, and various demographical factors can influence the frequency of flow experiences in different contexts. Analysis reveal that optimal experience during a social interaction is determined by the perceived level of challenges, the perceived level of cooperation, the immediateness and clarity of the feedback, and the level of the skill. Our study may contribute to the broadening purpose of positive psychology as it focuses on the interpersonal level in relation to flow experience, which, in turn, may also support a higher level of well-being. PMID:27247682

  4. Neural Representations of Physics Concepts.

    PubMed

    Mason, Robert A; Just, Marcel Adam

    2016-06-01

    We used functional MRI (fMRI) to assess neural representations of physics concepts (momentum, energy, etc.) in juniors, seniors, and graduate students majoring in physics or engineering. Our goal was to identify the underlying neural dimensions of these representations. Using factor analysis to reduce the number of dimensions of activation, we obtained four physics-related factors that were mapped to sets of voxels. The four factors were interpretable as causal motion visualization, periodicity, algebraic form, and energy flow. The individual concepts were identifiable from their fMRI signatures with a mean rank accuracy of .75 using a machine-learning (multivoxel) classifier. Furthermore, there was commonality in participants' neural representation of physics; a classifier trained on data from all but one participant identified the concepts in the left-out participant (mean accuracy = .71 across all nine participant samples). The findings indicate that abstract scientific concepts acquired in an educational setting evoke activation patterns that are identifiable and common, indicating that science education builds abstract knowledge using inherent, repurposed brain systems. PMID:27113732

  5. Neural Representations of Physics Concepts.

    PubMed

    Mason, Robert A; Just, Marcel Adam

    2016-06-01

    We used functional MRI (fMRI) to assess neural representations of physics concepts (momentum, energy, etc.) in juniors, seniors, and graduate students majoring in physics or engineering. Our goal was to identify the underlying neural dimensions of these representations. Using factor analysis to reduce the number of dimensions of activation, we obtained four physics-related factors that were mapped to sets of voxels. The four factors were interpretable as causal motion visualization, periodicity, algebraic form, and energy flow. The individual concepts were identifiable from their fMRI signatures with a mean rank accuracy of .75 using a machine-learning (multivoxel) classifier. Furthermore, there was commonality in participants' neural representation of physics; a classifier trained on data from all but one participant identified the concepts in the left-out participant (mean accuracy = .71 across all nine participant samples). The findings indicate that abstract scientific concepts acquired in an educational setting evoke activation patterns that are identifiable and common, indicating that science education builds abstract knowledge using inherent, repurposed brain systems.

  6. A Tangible Approach to Concept Mapping

    NASA Astrophysics Data System (ADS)

    Tanenbaum, Karen; Antle, Alissa N.

    2009-05-01

    The Tangible Concept Mapping project investigates using a tangible user interface to engage learners in concept map creation. This paper describes a prototype implementation of the system, presents some preliminary analysis of its ease of use and effectiveness, and discusses how elements of tangible interaction support concept mapping by helping users organize and structure their knowledge about a domain. The role of physical engagement and embodiment in supporting the mental activity of creating the concept map is explored as one of the benefits of a tangible approach to learning.

  7. Tools for the Study and Design of Collaborative Teacher Learning: The Affordances of Different Conceptions of Teacher Community and Activity Theory

    ERIC Educational Resources Information Center

    Levine, Thomas H.

    2010-01-01

    Teacher educators need tools to help them think about teacher learning, to design activities and programs that foster it, and to assess the results of their work with preservice and in-service teachers. In this article, in order to improve the conceptual tools available for the design and study of teacher education, the author teases apart…

  8. The NASA Advanced Propulsion Concepts at the Jet Propulsion Laboratory

    NASA Technical Reports Server (NTRS)

    Leifer, S. D.; Frisbee, R. H.; Brophy, J. R.

    1997-01-01

    Research activities in advanced propulsion concepts at the Jet Propulsion Laboratory are reviewed. The concepts were selected for study because each offers the potential for either significantly enhancing space transportation capability or enabling bold, ambitious new missions.

  9. Evolving Ethical Concepts

    ERIC Educational Resources Information Center

    Potter, Van Rensselaer

    1977-01-01

    Discusses the role of the scientist in changing ethical concepts from simple interpersonal and theological imperatives towards "survival imperatives that must form the core of environmental bioethics." (CS)

  10. The aryl hydrocarbon receptor-activating effect of uremic toxins from tryptophan metabolism: a new concept to understand cardiovascular complications of chronic kidney disease.

    PubMed

    Sallée, Marion; Dou, Laetitia; Cerini, Claire; Poitevin, Stéphane; Brunet, Philippe; Burtey, Stéphane

    2014-03-04

    Patients with chronic kidney disease (CKD) have a higher risk of cardiovascular diseases and suffer from accelerated atherosclerosis. CKD patients are permanently exposed to uremic toxins, making them good candidates as pathogenic agents. We focus here on uremic toxins from tryptophan metabolism because of their potential involvement in cardiovascular toxicity: indolic uremic toxins (indoxyl sulfate, indole-3 acetic acid, and indoxyl-β-d-glucuronide) and uremic toxins from the kynurenine pathway (kynurenine, kynurenic acid, anthranilic acid, 3-hydroxykynurenine, 3-hydroxyanthranilic acid, and quinolinic acid). Uremic toxins derived from tryptophan are endogenous ligands of the transcription factor aryl hydrocarbon receptor (AhR). AhR, also known as the dioxin receptor, interacts with various regulatory and signaling proteins, including protein kinases and phosphatases, and Nuclear Factor-Kappa-B. AhR activation by 2,3,7,8-tetrachlorodibenzo-p-dioxin and some polychlorinated biphenyls is associated with an increase in cardiovascular disease in humans and in mice. In addition, this AhR activation mediates cardiotoxicity, vascular inflammation, and a procoagulant and prooxidant phenotype of vascular cells. Uremic toxins derived from tryptophan have prooxidant, proinflammatory, procoagulant, and pro-apoptotic effects on cells involved in the cardiovascular system, and some of them are related with cardiovascular complications in CKD. We discuss here how the cardiovascular effects of these uremic toxins could be mediated by AhR activation, in a "dioxin-like" effect.

  11. Design Concepts. Teacher Edition. Marketing Education LAPs.

    ERIC Educational Resources Information Center

    Hawley, Jana

    This learning activity packet is designed to help prepare students to acquire a competency: how to use design concepts in preparation for a career in the fashion industry. The unit consists of the competency, four objectives, suggested learning activities, transparency masters, and a pretest/posttest with answer keys. Activities include a…

  12. Reinforcing key concepts in the discipline of geobiology through active learning in the field - an example integrating middle school through graduate school students

    NASA Astrophysics Data System (ADS)

    Gilhooly, W., III; Werne, J. P.; O'Beirne, M.; Johnson, E.; Martin, P. A.; Harris, J. H., IV; Fouskas, F.; Steinman, B. A.

    2015-12-01

    Our goal was to introduce students to current research in the scientific discipline of geobiology. To accomplish this, we established a three-fold approach to link course work with fieldwork through: 1) active participation in the field and laboratory, 2) multi-tiered mentoring, 3) and formal education modules. During the summer of 2015, six undergraduate students and seven graduate students collected field samples from Green Lake (NY) and Mahoney Lake (BC). The students learned how to take water and sediment samples, process samples in anaerobic chambers in the field, and deal with moderately adverse field conditions. These learning by doing activities reinforced lessons learned in the classroom. The second phase involved two high school students who helped process and analyze the samples in the laboratory during summer session. These students worked with the undergraduate and graduate students who participated in the fieldwork. This interaction benefited both the high school students, who learned new methods, and the university students who learned to explain their field research and mentor younger students. The third phase involved creation of education modules to better inform middle school students of the issues of hypoxia. We piloted portions of our module at a conference for forty middle school girls. Graduate students showed the girls field equipment and how to make oxygen measurements using handheld instruments. In all of these activities, the students had the opportunity to work with the PI's, who were fully engaged in the process and who made a constant effort to be educators in the field and in the lab.

  13. Shared mission operations concept

    NASA Technical Reports Server (NTRS)

    Spradlin, Gary L.; Rudd, Richard P.; Linick, Susan H.

    1994-01-01

    Historically, new JPL flight projects have developed a Mission Operations System (MOS) as unique as their spacecraft, and have utilized a mission-dedicated staff to monitor and control the spacecraft through the MOS. NASA budgetary pressures to reduce mission operations costs have led to the development and reliance on multimission ground system capabilities. The use of these multimission capabilities has not eliminated an ongoing requirement for a nucleus of personnel familiar with a given spacecraft and its mission to perform mission-dedicated operations. The high cost of skilled personnel required to support projects with diverse mission objectives has the potential for significant reduction through shared mission operations among mission-compatible projects. Shared mission operations are feasible if: (1) the missions do not conflict with one another in terms of peak activity periods, (2) a unique MOS is not required, and (3) there is sufficient similarity in the mission profiles so that greatly different skills would not be required to support each mission. This paper will further develop this shared mission operations concept. We will illustrate how a Discovery-class mission would enter a 'partner' relationship with the Voyager Project, and can minimize MOS development and operations costs by early and careful consideration of mission operations requirements.

  14. Concepts of fever.

    PubMed

    Mackowiak, P A

    1998-09-28

    If asked to define fever, most physicians would offer a thermal definition, such as "fever is a temperature greater than...." In offering their definition, many would ignore the importance of the anatomic site at which temperature measurements are taken, as well as the diurnal oscillations that characterize body temperature. If queried about the history of clinical thermometry, few physicians could identify the source or explain the pertinacity of the belief that 98.6 degrees F (37.0 degrees C) has special meaning vis-à-vis normal body temperature. Fewer still could cite the origin of the thermometer or trace the evolution of modern concepts of clinical thermometry. Although many would have some knowledge of the fundamentals of thermoregulation and the role played by exogenous and endogenous pyrogens in the induction of fever, few would have more than a superficial knowledge of the broad biological activities of pyrogenic cytokines or know of the existence of an equally complex and important system of endogenous cryogens. A distinct minority would appreciate the obvious paradoxes inherent in an enlarging body of data concerned with the question of fever's adaptive value. The present review considers many of these issues in the light of current data. PMID:9759682

  15. Novel concept in the mechanism of injury and protection of gastric mucosa: role of renin-angiotensin system and active metabolites of angiotensin.

    PubMed

    Brzozowski, T; Ptak-Belowska, A; Kwiecien, S; Krzysiek-Maczka, G; Strzalka, M; Drozdowicz, D; Pajdo, R; Olszanecki, R; Korbut, R; Konturek, S J; Pawlik, W W

    2012-01-01

    The term cytoprotection pioneered by Robert and colleagues has been introduced to describe the remarkable ability of endogenous and exogenous prostaglandins (PGs) to prevent acute gastric hemorrhagic lesions induced by noxious stimuli such as ethanol, bile acids, hiperosmolar solutions and nonsteroidal anti-inflammatory agents such as aspirin. Since that time many factors were implicated to possess gastroprotective properties such as growth factors including epidermal growth factor (EGF) and transforming factor alpha (TGFα), vasodilatory mediators such as nitric oxide (NO) and calcitonin gene related peptide (CGRP) as well as appetite gut hormones including gastrin and cholecystokinin (CCK), leptin and recently ghrelin. This protective action of gut peptides has been attributed to the release of PG but question remains whether another peptide angiotensin, the classic component of the systemic and local renin-angiotensin system (RAS) could be involved in the mechanism of gastric integrity and gastroprotection. After renin stimulation, the circulating angiotensin I is converted to angiotensin II (ANG II) by the activity of the Angiotensin Converting Enzyme (ACE). The ANG II acting via its binding to two major receptor subtypes the ANG type 1 (AT1) and type 2 (AT2) has been shown be activated during stress and to contribute to the pathogenesis of cold stress- and ischemia-reperfusion-induced gastric lesions. All bioactive angiotensin peptides can be generated not only in systemic circulation, but also locally in several tissues and organs. Recently the new functional components of RAS, such as Ang-(1-7), Ang IV, Ang-(1-12) and novel pathways ACE2 have been described suggesting the gastroprotective role for the novel ANG II metabolite, Ang-(1-7). The fact that Ang-(1-7) is produced in excessive amounts in the gastric mucosa of rodents and that pretreatment by Ang-(1-7) exhibits a potent gastroprotective activity against the gastric lesions induced by cold

  16. Using Graph Components Derived from an Associative Concept Dictionary to Predict fMRI Neural Activation Patterns that Represent the Meaning of Nouns.

    PubMed

    Akama, Hiroyuki; Miyake, Maki; Jung, Jaeyoung; Murphy, Brian

    2015-01-01

    In this study, we introduce an original distance definition for graphs, called the Markov-inverse-F measure (MiF). This measure enables the integration of classical graph theory indices with new knowledge pertaining to structural feature extraction from semantic networks. MiF improves the conventional Jaccard and/or Simpson indices, and reconciles both the geodesic information (random walk) and co-occurrence adjustment (degree balance and distribution). We measure the effectiveness of graph-based coefficients through the application of linguistic graph information for a neural activity recorded during conceptual processing in the human brain. Specifically, the MiF distance is computed between each of the nouns used in a previous neural experiment and each of the in-between words in a subgraph derived from the Edinburgh Word Association Thesaurus of English. From the MiF-based information matrix, a machine learning model can accurately obtain a scalar parameter that specifies the degree to which each voxel in (the MRI image of) the brain is activated by each word or each principal component of the intermediate semantic features. Furthermore, correlating the voxel information with the MiF-based principal components, a new computational neurolinguistics model with a network connectivity paradigm is created. This allows two dimensions of context space to be incorporated with both semantic and neural distributional representations. PMID:25928363

  17. Using Graph Components Derived from an Associative Concept Dictionary to Predict fMRI Neural Activation Patterns that Represent the Meaning of Nouns

    PubMed Central

    Akama, Hiroyuki; Miyake, Maki; Jung, Jaeyoung; Murphy, Brian

    2015-01-01

    In this study, we introduce an original distance definition for graphs, called the Markov-inverse-F measure (MiF). This measure enables the integration of classical graph theory indices with new knowledge pertaining to structural feature extraction from semantic networks. MiF improves the conventional Jaccard and/or Simpson indices, and reconciles both the geodesic information (random walk) and co-occurrence adjustment (degree balance and distribution). We measure the effectiveness of graph-based coefficients through the application of linguistic graph information for a neural activity recorded during conceptual processing in the human brain. Specifically, the MiF distance is computed between each of the nouns used in a previous neural experiment and each of the in-between words in a subgraph derived from the Edinburgh Word Association Thesaurus of English. From the MiF-based information matrix, a machine learning model can accurately obtain a scalar parameter that specifies the degree to which each voxel in (the MRI image of) the brain is activated by each word or each principal component of the intermediate semantic features. Furthermore, correlating the voxel information with the MiF-based principal components, a new computational neurolinguistics model with a network connectivity paradigm is created. This allows two dimensions of context space to be incorporated with both semantic and neural distributional representations. PMID:25928363

  18. Children's Conceptions of Jesus

    ERIC Educational Resources Information Center

    Aylward, Karen; Freathy, Rob

    2008-01-01

    This paper presents findings from a recent study investigating young children's (aged 10-11) conceptions of Jesus in England. The overall picture revealed by the study is that whilst there was a general assent amongst pupils in our sample towards an ethical and humanistic conception of the historical Jesus, there was less of a consensus about…

  19. The Concept of Information.

    ERIC Educational Resources Information Center

    Capurro, Rafael; Hjorland, Birger

    2003-01-01

    Reviews the status of the concept of information in information science, with reference to interdisciplinary trends. Highlights include defining scientific terms; studies and sources of the word information; the concept of information in the natural sciences, and in the humanities and social sciences; librarianship; information retrieval; and the…

  20. Badminton--Teaching Concepts.

    ERIC Educational Resources Information Center

    Gibbs, Marilyn J.

    1988-01-01

    Teaching four basic badminton concepts along with the usual basic skill shots allows players to develop game strategy awareness as well as mechanical skills. These four basic concepts are: (1) ready position, (2) flight trajectory, (3) early shuttle contact, and (4) camouflage. (IAH)

  1. Learning Our Concepts

    ERIC Educational Resources Information Center

    Laverty, Megan J.

    2009-01-01

    Richard Stanley Peters appreciates the centrality of concepts for everyday life, however, he fails to recognize their pedagogical dimension. He distinguishes concepts employed at the first-order (our ordinary language-use) from second-order conceptual clarification (conducted exclusively by academically trained philosophers). This distinction…

  2. Children's Concepts of Death.

    ERIC Educational Resources Information Center

    Kane, Barbara

    1979-01-01

    A total of 122 middle-class White boys and girls aged 3 through 12 years were interviewed to determine the nature and the development of their concepts of death and the impact of experience on those concepts. (Author/BH)

  3. New Concepts of Work.

    ERIC Educational Resources Information Center

    Canadian Council on Social Development, Ottawa (Ontario).

    The two-day Canadian conference focused on the topics: "Why are new concepts of work emerging?" and "How can we encourage desirable new work concepts in our society?" Following an introductory summary by David P. Ross, Stephen Peitchinis (Dean, School of Business Administration, University of Calgary) presented the economic circumstances of the…

  4. Values Concepts and Techniques.

    ERIC Educational Resources Information Center

    National Education Association, Washington, DC.

    This book contains 29 articles for elementary and secondary teachers dealing with fundamental concepts and teaching techniques in values education. Part one of the book deals with concepts. Louis E. Raths examines valuing and its relationship to freedom and intelligence. The cognitive developmental approach to moral education is discussed by…

  5. The Concept of Density

    ERIC Educational Resources Information Center

    Hawkes, Stephen J.

    2004-01-01

    Students are aware of the theoretical or abstract concept of density, but fail to understand its practical implication in that the thickness concentrated in a solid object is what constitutes density. A study of the density concept reveals its very practical and qualitative nature, and the students must look beyond theoretical equations to…

  6. Threshold Concepts in Economics

    ERIC Educational Resources Information Center

    Shanahan, Martin

    2016-01-01

    Purpose: The purpose of this paper is to examine threshold concepts in the context of teaching and learning first-year university economics. It outlines some of the arguments for using threshold concepts and provides examples using opportunity cost as an exemplar in economics. Design/ Methodology/Approach: The paper provides an overview of the…

  7. Progress on DCLL Blanket Concept

    SciTech Connect

    Wong, Clement; Abdou, M.; Katoh, Yutai; Kurtz, Richard J.; Lumsdaine, A.; Marriott, Edward P.; Merrill, Brad; Morley, Neil; Pint, Bruce A.; Sawan, M.; Smolentsev, S.; Williams, Brian; Willms, Scott; Youssef, M.

    2013-09-01

    Under the US Fusion Nuclear Science and Technology Development program, we have selected the Dual Coolant Lead Lithium concept (DCLL) as a reference blanket, which has the potential to be a high performance DEMO blanket design with a projected thermal efficiency of >40%. Reduced activation ferritic/martensitic (RAF/M) steel is used as the structural material. The self-cooled breeder PbLi is circulated for power conversion and for tritium breeding. A SiC-based flow channel insert (FCI) is used as a means for magnetohydrodynamic pressure drop reduction from the circulating liquid PbLi and as a thermal insulator to separate the high-temperature PbLi (~700°C) from the helium-cooled RAF/M steel structure. We are making progress on related R&D needs to address critical Fusion Nuclear Science and Facility (FNSF) and DEMO blanket development issues. When performing the function as the Interface Coordinator for the DCLL blanket concept, we had been developing the mechanical design and performing neutronics, structural and thermal hydraulics analyses of the DCLL TBM module. We had estimated the necessary ancillary equipment that will be needed at the ITER site and a detailed safety impact report has been prepared. This provided additional understanding of the DCLL blanket concept in preparation for the FNSF and DEMO. This paper will be a summary report on the progress of the DCLL TBM design and R&Ds for the DCLL blanket concept.

  8. Accelerated development and flight evaluation of active controls concepts for subsonic transport aircraft. Volume 2: AFT C.G. simulation and analysis

    NASA Technical Reports Server (NTRS)

    Urie, D. M.

    1979-01-01

    Relaxed static stability and stability augmentation with active controls were investigated for subsonic transport aircraft. Analytical and simulator evaluations were done using a contemporary wide body transport as a baseline. Criteria for augmentation system performance and unaugmented flying qualities were evaluated. Augmentation control laws were defined based on selected frequency response and time history criteria. Flying qualities evaluations were conducted by pilots using a moving base simulator with a transport cab. Static margin and air turbulence intensity were varied in test with and without augmentation. Suitability of a simple pitch control law was verified at neutral static margin in cruise and landing flight tasks. Neutral stability was found to be marginally acceptable in heavy turbulence in both cruise and landing conditions.

  9. Early integration of the individual student in academic activities: a novel classroom concept for graduate education in molecular biophysics and structural biology

    PubMed Central

    2014-01-01

    Background A key challenge in interdisciplinary research is choosing the best approach from a large number of techniques derived from different disciplines and their interfaces. Results To address this challenge in the area of Biophysics and Structural Biology, we have designed a graduate level course to teach students insightful use of experimental biophysical approaches in relationship to addressing biological questions related to biomolecular interactions and dynamics. A weekly seminar and data and literature club are used to compliment the training in class. The course contains wet-laboratory experimental demonstration and real-data analysis as well as lectures, grant proposal preparation and assessment, and student presentation components. Active student participation is mandatory in all aspects of the class. Students prepare materials for the class receiving individual and iterative feedback from course directors and local experts generating high quality classroom presentations. Conclusions The ultimate goal of the course is to teach students the skills needed to weigh different experimental approaches against each other in addressing a specific biological question by thinking and executing academic tasks like faculty. PMID:25132964

  10. See your GP, see the world – An activating course concept for fostering students' competence in performing vaccine and travel consultations

    PubMed Central

    Beltermann, Esther; Krane, Sibylla; Kiesewetter, Jan; Fischer, Martin R.; Schelling, Jörg

    2015-01-01

    Aim: Performing vaccine and travel consultations is a crucial aspect of the daily routine in general medicine. However, medical education does not provide adequately and structured training for this future task of medical students. While existing courses mainly focus on theoretical aspects, we developed a course aiming to foster practical experience in performing vaccine and travel consultations. Project report: The course was implemented in the simulation clinic at the University of Munich in the summer 2011 semester using role-plays in a simulation-based learning environment. The course represents different disciplines involved in vaccine and travel medicine. Students’ learning is supported through active engagement in planning and conducting consultations of patients. Discussion and Summary: The course was implemented successfully and students’ acceptance was high. However, there is a need for structured teaching of theoretical basics in vaccine and travel medicine earlier in medical curriculum. The insights gained through our course are used for the development of the structured longitudinal curriculum “vaccine medicine”. PMID:26413166

  11. What's in a Word? Concept mapping: a graphical tool to reinforce learning of epidemiological concepts.

    PubMed

    Berglund, Anita

    2015-12-01

    Epidemiology is founded on central concepts and principles, essential for conducting, reporting and critically assessing epidemiological studies. Definitions of the many concepts used in the field can be found in textbooks and via the Dictionary of Epidemiology. However, central epidemiological concepts are labelled and used in multiple ways, leading to potential misunderstanding when communicating in different fora. The aim here is to describe collaborative concept mapping, and illustrate how it can be used in teaching and learning epidemiology. Concept mapping is a cognitive technique that is widely used in the education of medical and allied health professions as a tool for critical thinking, and to assimilate new knowledge, but it is still under-utilised in epidemiology. A specific concept map is defined by the aim and question in focus; it is thus framed by a context. The concept map is constructed using a set of concepts (nodes) that are linked with arrows or lines (links). Words and phrases (connective terms) are used to explain relationships between the concepts linked. Different domains can be interconnected by linking concepts in different areas (cross-links). The underlying structure of knowledge is often complex, and consequently concept maps can be constructed using different topological features. Here we provide an illustrative example of concept mapping, based on a set of 'basic' concepts introduced in a doctoral course in epidemiology. In summary, concept mapping is a compelling, active learning tool, which can promote shared deeper knowledge of concepts and their complex interconnections, thereby facilitating a better understanding of epidemiological research. PMID:25987721

  12. Evolution of concepts of stress.

    PubMed

    Goldstein, David S; Kopin, Irwin J

    2007-06-01

    This essay describes the evolution of stress as a medical scientific idea. Claude Bernard, Walter B. Cannon and Hans Selye provided key founding concepts for the current view. Bernard introduced the idea of the internal environment bathing cells - the milieu intérieur - maintained by continual compensatory changes of bodily functions. Cannon coined the word, "homeostasis," referring to a set of acceptable ranges of values for internal variables. Cannon taught that threats to homeostasis evoke activation of the sympathoadrenal system as a functional unit. Selye defined stress as a state characterized by a uniform response pattern, regardless of the particular stressor, that could lead to long-term pathologic changes. "Allostasis" was introduced as a concept in recognition that there is no single ideal set of steady-state conditions in life; instead, setpoints and other response criteria change continuously. Stress is now viewed neither as a perturbation nor a stereotyped response pattern but as a condition characterized by a perceived discrepancy between information about a monitored variable and criteria for eliciting patterned effector responses. Different stressors elicit different patterns of activation of the sympathetic nervous, adrenomedullary hormonal, hypothalamic-pituitary-adrenocortical and other effectors, closing negative feedback loops. This systems concept of stress yields predictions that observation or experimentation can test and that are applicable to normal physiology and to a variety of acute and chronic disorders.

  13. Evolution of concepts of stress.

    PubMed

    Goldstein, David S; Kopin, Irwin J

    2007-06-01

    This essay describes the evolution of stress as a medical scientific idea. Claude Bernard, Walter B. Cannon and Hans Selye provided key founding concepts for the current view. Bernard introduced the idea of the internal environment bathing cells - the milieu intérieur - maintained by continual compensatory changes of bodily functions. Cannon coined the word, "homeostasis," referring to a set of acceptable ranges of values for internal variables. Cannon taught that threats to homeostasis evoke activation of the sympathoadrenal system as a functional unit. Selye defined stress as a state characterized by a uniform response pattern, regardless of the particular stressor, that could lead to long-term pathologic changes. "Allostasis" was introduced as a concept in recognition that there is no single ideal set of steady-state conditions in life; instead, setpoints and other response criteria change continuously. Stress is now viewed neither as a perturbation nor a stereotyped response pattern but as a condition characterized by a perceived discrepancy between information about a monitored variable and criteria for eliciting patterned effector responses. Different stressors elicit different patterns of activation of the sympathetic nervous, adrenomedullary hormonal, hypothalamic-pituitary-adrenocortical and other effectors, closing negative feedback loops. This systems concept of stress yields predictions that observation or experimentation can test and that are applicable to normal physiology and to a variety of acute and chronic disorders. PMID:17514579

  14. Feminism: a concept analysis.

    PubMed

    Allan, H T

    1993-10-01

    The purpose of this paper is to analyse the concept of feminism in order to clarify a sociological concept for its use in nursing theory and practice. This analysis is carried out using the Walker & Avant (1988) model. It includes: a literature review, an overview of the uses of the concept drawn from the literature, the defining attributes and the justification of their choice, the cases to demonstrate the concept, and the concept criteria. The concept was chosen out of an interest in developing a feminist nursing theory and desire to enhance nursing practice. The literature search proved most fruitful in the sociological literature. The nursing sources were fewer and concerned with practice rather than articulating any feminist nursing theory. Many of these sources were sociologists and nurses. The concept of feminism was defined as the concern with gender equality and the promotion of equal rights for men and woman, the expression of these concerns through theory or action, and the valuing of individuals for their contributions to society rather than their biological or sexual characteristics or roles. Although the concept of feminism was defined and analysed within the model suggested by Walker & Avant, the author found that the concept became oversimplified, losing much of the richness of the literature. The author felt that, for any development of theory or practice, this analysis would have to be expanded. It is argued that their model is too restrictive as it is based on positivist philosophy which seeks to establish divisions where, in fact, there is a blurring of meaning.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Advanced concepts for acceleration

    SciTech Connect

    Keefe, D.

    1986-07-01

    Selected examples of advanced accelerator concepts are reviewed. Such plasma accelerators as plasma beat wave accelerator, plasma wake field accelerator, and plasma grating accelerator are discussed particularly as examples of concepts for accelerating relativistic electrons or positrons. Also covered are the pulsed electron-beam, pulsed laser accelerator, inverse Cherenkov accelerator, inverse free-electron laser, switched radial-line accelerators, and two-beam accelerator. Advanced concepts for ion acceleration discussed include the electron ring accelerator, excitation of waves on intense electron beams, and two-wave combinations. (LEW)

  16. Space-Borne Remote Sensing of Soil Moisture and Freeze/Thaw Dynamics at High Resolution Using a Combined Active and Passive Instrument Concept

    NASA Astrophysics Data System (ADS)

    Entekhabi, D.; Njoku, E. G.; Houser, P.; Gurney, R.; Jackson, T.; Kimball, J.; Koster, R.; McDonald, K.; ONeill, P.; Running, S.; VanZyl, J.; Wood, E. F.

    2001-05-01

    The design and expected characteristics of a space-borne system for high-resolution mapping of surface soil moisture and soil freeze/thaw dynamics is presented. This study represents the proposal for a comprehensive terrestrial hydrology monitoring mission. The mission objective is traced to the data requirements of research related to predictability, variations and change in the rate of the hydrologic cycle. The baseline mission builds on the heritage of ground-based and airborne passive and active low frequency microwave measurements that have demonstrated and validated the effectiveness of the measurements and associated algorithms for estimating the amount and phase of surface soil moisture. The satellite has both a radiometer and a radar on board. The radiometer provides polarized brightness temperature fields at 1.4 GHz across a wide swath (~ 900 km) at a resolution of 40 km. The radar operates at 1.2 GHz (VV, HH, and HV) and is capable of high-resolution mapping (less than 3 km) over 70 percent of the swath and low-resolution across the remainder. All terrestrial land regions are revisited within 2-3 days. The instrument uses a light-weight deployable mesh reflector antenna to make conical scans at a constant-incidence angle. The antenna scans at 6 rpm to generate the wide swath and mapping coverage. The algorithm design for producing 40 km and 10 km soil moisture and freeze/thaw data products and 3 km freeze/thaw and inundation extent products will be described. The strategy for estimating and correcting for wet biomass masking of the soil moisture and freeze/thaw signal by vegetation (with cover less than forest cover) will be presented. Finally we present a strategy for using data assimilation to use the synergy of measurements from other platforms, in situ data, and physical constraints on water and energy transports and balances to develop value-added data products that are continuous in time and provide estimates of soil water availability in the root

  17. [The concept of happiness].

    PubMed

    Yampey, N

    1980-12-01

    The author points to the universal character of this complex psychic reality, i.e. happiness, and intends to define and describe its characteristics. Etymologically speaking, it means joy that is experienced through the object reached or the objective achieved, achievements which presuppose activity and effort. This psychological state is a pleasant, relative and dynamic one and shows itself up through the impulses that lead to spontaneous actions which are in harmony with the fundamental tendencies of the subject. They are not alien to running risks and to the will of victory. Some people believe happiness is attained at random, others think it is an art and a science to be developped by voluntary effort. Limited as it is by the order of universe and human constitution, its being a spiritual condition conveys a transcendency to it but by the same token it implies the sacrifice of immediate pleasure. Love between two people is its paramount paradigm. Love originates in sexual attraction but in its development and at its summit there is tenderness and companionship in a mutual relation between two people who share their genitality. Individual happiness is inseparable of collective happiness and on this idea stands social welfare. From the psychoanalytical point of view, the feeling of happiness relates itself to the personality as a whole and presupposes the cooperation in harmony of all the constituents of the self. It occurs when there is an experience of unity between Ego and World, Id or Ego Ideal, unity which is a consequence of having liberated oneself from the repressive instance. It is the result of a synthetic process, is essentially endogenous and is reached by the linking force of narcissistic libido. It is submitted to internal laws, that is why it possesses a passing condition. Enjoyment of happiness presupposes psychic integration and in this sense it is related to the modern health approach as stated by World Health Organization. In this conference

  18. The effects of the level of inquiry of situated secondary science laboratory activities on students' understanding of concepts and the nature of science, ability to use process skills and attitudes toward problem solving

    NASA Astrophysics Data System (ADS)

    Dana, Lisa Ann

    Although there has been over thirty years of studies on the effects of inquiry-based science instruction on students' understanding of concepts and the nature of science, ability to use process skills, and attitudes toward problem solving and subsequent meta-analyses of these studies, little is conclusive because of the inability of researchers to adequately describe the various levels of inquiry-based science instruction being utilized. In many of these past studies inquiry-based science instruction was vaguely defined. Past descriptions of inquiry have mainly focused on the teacher vs. student responsibility in the parts of a laboratory activity (Herron 1971, Pella, 1961, and Schwab, 1962) and although others have since focused on other various aspects (Luft, 1999; Priestley, Priestley, Sutman, Schumuckler, Hilosky, & White 1998), none have been complete in scope to describe the classroom interactions between teacher and student, before, during and after manipulation of laboratory materials and to clearly define the various levels of inquiry-based science instruction occurring in a classroom. Utilizing some of these previous theoretical frameworks, this study created the Situated Laboratory Activity Instrument (SLAI) that clearly defines various levels of inquiry based upon specific categories of teacher-student behaviors. The term, situated laboratory activities, more clearly represents the time before, during and after the actual manipulation of material. Validity and reliability were established for the SLAI. The instrument was derived from both historical and current instruments for looking at inquiry. The data for the creation and revision of this instrument were collected through initial reliability measures and observing the situated laboratory activities in four secondary physics classrooms during the study. The SLAI was utilized in a preliminary study in a public high school of the effects of various levels of inquiry teaching on students' understanding

  19. Concepts in Change

    NASA Astrophysics Data System (ADS)

    Rusanen, Anna-Mari; Pöyhönen, Samuli

    2013-06-01

    In this article we focus on the concept of concept in conceptual change. We argue that (1) theories of higher learning must often employ two different notions of concept that should not be conflated: psychological and scientific concepts. The usages for these two notions are partly distinct and thus straightforward identification between them is unwarranted. Hence, the strong analogy between scientific theory change and individual learning should be approached with caution. In addition, we argue that (2) research in psychology and cognitive science provides a promising theoretical basis for developing explanatory mechanistic models of conceptual change. Moreover, we argue that (3) arguments against deeper integration between the fields of psychology and conceptual change are not convincing, and that recent theoretical developments in the cognitive sciences might prove indispensable in filling in the details in mechanisms of conceptual change.

  20. Common tester platform concept.

    SciTech Connect

    Hurst, Michael James

    2008-05-01

    This report summarizes the results of a case study on the doctrine of a common tester platform, a concept of a standardized platform that can be applicable across the broad spectrum of testing requirements throughout the various stages of a weapons program, as well as across the various weapons programs. The common tester concept strives to define an affordable, next-generation design that will meet testing requirements with the flexibility to grow and expand; supporting the initial development stages of a weapons program through to the final production and surveillance stages. This report discusses a concept investing key leveraging technologies and operational concepts combined with prototype tester-development experiences and practical lessons learned gleaned from past weapons programs.

  1. Blazars: Artist Conception

    NASA Video Gallery

    What astronomers once thought were two blazar families may in fact be one, as shown in this artist's concept. Energy stored in the black hole during its salad days of intense accretion may later be...

  2. Space Station - early concept

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Wind tunnel model of Manned Orbiting Research Laboratory concept on sting. Published in James R. Hansen, Spaceflight Revolution: NASA Langley Research Center From Sputnik to Apollo, (Washington: NASA, 1995).

  3. Space Station - early concept

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Display model of space station concept--Manned Orbiting Research Laboratory in Saturn S-IVB Orbit configuration. Published in James R. Hansen, Spaceflight Revolution: NASA Langley Research Center From Sputnik to Apollo, (Washington: NASA, 1995).

  4. Concept analysis: resilience.

    PubMed

    Garcia-Dia, Mary Joy; DiNapoli, Jean Marie; Garcia-Ona, Leila; Jakubowski, Rita; O'Flaherty, Deirdre

    2013-12-01

    This paper will systematically analyze the concept of resilience using an integrated review of literature. The historical perspective, attributes, antecedents, and consequences of resilience will be reviewed. A theoretical and operational definition will be provided. The Walker and Avant method will be used to describe the cases. Finally, the use of concept map will capture the relationships among the attributes, antecedents, consequences, and empirical indicators through clustering and chaining. PMID:24238005

  5. Overcoming: A Concept Analysis

    PubMed Central

    Brush, Barbara L.; Kirk, Keri; Gultekin, Laura; Baiardi, Janet M.

    2011-01-01

    This article provides an operational definition of overcoming as a first step in the systematic analysis of the concept. Using the method described by Walker and Avant (2005), the authors identify the attributes and characteristics of overcoming and its theoretical and practical application to nursing. Sample cases from clinical research illustrate the concept further. Further nursing research needs to test the theoretical relationships between overcoming and outcome variables. PMID:21806626

  6. [Mindfulness: A Concept Analysis].

    PubMed

    Chen, Tsai-Ling; Chou, Fan-Hao; Wang, Hsiu-Hung

    2016-04-01

    "Mindfulness" is an emerging concept in the field of healthcare. Ranging from stress relief to psychotherapy, mindfulness has been confirmed to be an effective tool to help individuals manage depression, anxiety, obsessive-compulsive disorder, and other health problems in clinical settings. Scholars currently use various definitions for mindfulness. While some of these definitions overlap, significant differences remain and a general scholarly consensus has yet to be reached. Several domestic and international studies have explored mindfulness-related interventions and their effectiveness. However, the majority of these studies have focused on the fields of clinical medicine, consultation, and education. Mindfulness has rarely been applied in clinical nursing practice and no related systematic concept analysis has been conducted. This paper conducts a concept analysis of mindfulness using the concept analysis method proposed by Walker and Avant (2011). We describe the defining characteristics of mindfulness, clarify the concept, and confirm the predisposing factors and effects of mindfulness using examples of typical cases, borderline cases, related cases, and contrary case. Findings may provide nursing staff with an understanding of the concept of mindfulness for use in clinical practice in order to help patients achieve a comfortable state of body and mind healing.

  7. Evaluation of Students' Energy Conception in Environmental Science

    ERIC Educational Resources Information Center

    Park, Mihwa; Johnson, Joseph A.

    2016-01-01

    While significant research has been conducted on students' conceptions of energy, alternative conceptions of energy have not been actively explored in the area of environmental science. The purpose of this study is to examine students' alternative conceptions in the environmental science discipline through the analysis of responses of first year…

  8. "Structural Transformation" as a Threshold Concept in University Teaching

    ERIC Educational Resources Information Center

    Kinchin, Ian M.; Miller, Norma L.

    2012-01-01

    In an attempt to reveal potential threshold concepts in the field of higher education pedagogy, groups of university teachers (in the UK and in Panama) were encouraged to develop personal reflection upon their conceptions of teaching. This was initiated through concept mapping activities. It was hoped that this would help participants to address…

  9. Learning from Concept Mapping and Hypertext: An Eye Tracking Study

    ERIC Educational Resources Information Center

    Amadieu, Franck; Salmerón, Ladislao; Cegarra, Julien; Paubel, Pierre-Vincent; Lemarié, Julie; Chevalier, Aline

    2015-01-01

    This study examined the effects of prior domain knowledge and learning sequences on learning with concept mapping and hypertext. Participants either made a concept map in a first step and then read the hypertext's contents combined with concept mapping (high activating condition), or they read the hypertext's contents first and then made a concept…

  10. Integrating Concept Networks and HyperMedia.

    ERIC Educational Resources Information Center

    Scott, Peter J.; Ardron, David J.

    This paper reports on an integration of concept mapping for manipulating and structuring knowledge with multimedia presentation technology. The intelligent hypermedia system HAN (hypermedia activated network) is an authoring environment that generates small hypermedia tutorials online as they are required. A student query activates a portion of a…

  11. 21st Century Conceptions of Musical Ability

    ERIC Educational Resources Information Center

    Hallam, Susan

    2010-01-01

    This study explored conceptions of musical ability using an inventory derived from previous qualitative research. Participants included 102 musicians, 95 educators, 132 adult amateur musicians, 60 adults who were not actively engaged in making music, 193 children actively engaged in making music in addition to their engagement with the school…

  12. Space Debris Environment Remediation Concepts

    NASA Technical Reports Server (NTRS)

    Johnson, Nicholas L.; Klinkrad, Heiner

    2009-01-01

    Long-term projections of the space debris environment indicate that even drastic measures, such as an immediate, complete halt of launch and release activities, will not result in a stable environment of man-made space objects. Collision events between already existing space hardware will within a few decades start to dominate the debris population, and result in a net increase of the space debris population, also in size regimes which may cause further catastrophic collisions. Such a collisional cascading will ultimately lead to a run-away situation ("Kessler syndrome"), with no further possibility of human intervention. The International Academy of Astronautics (IAA) has been investigating the status and the stability of the space debris environment in several studies by first looking into space traffic management possibilities and then investigating means of mitigating the creation of space debris. In an ongoing activity, an IAA study group looks at ways of active space debris environment remediation. In contrast to the former mitigation study, the current activity concentrates on the active removal of small and large objects, such as defunct spacecraft, orbital stages, and mission-related objects, which serve as a latent mass reservoir that fuels initial catastrophic collisions and later collisional cascading. The paper will outline different mass removal concepts, e.g. based on directed energy, tethers (momentum exchange or electrodynamic), aerodynamic drag augmentation, solar sails, auxiliary propulsion units, retarding surfaces, or on-orbit capture. Apart from physical principles of the proposed concepts, their applicability to different orbital regimes, and their effectiveness concerning mass removal efficiency will be analyzed. The IAA activity on space debris environment remediation is a truly international project which involves more than 23 contributing authors from 9 different nations.

  13. Advanced fusion concepts: project summaries

    SciTech Connect

    1980-12-01

    This report contains descriptions of the activities of all the projects supported by the Advanced Fusion Concepts Branch of the Office of Fusion Energy, US Department of Energy. These descriptions are project summaries of each of the individual projects, and contain the following: title, principle investigators, funding levels, purpose, approach, progress, plans, milestones, graduate students, graduates, other professional staff, and recent publications. Information is given for each of the following programs: (1) reverse-field pinch, (2) compact toroid, (3) alternate fuel/multipoles, (4) stellarator/torsatron, (5) linear magnetic fusion, (6) liners, and (7) Tormac. (MOW)

  14. Concept Analysis: Music Therapy.

    PubMed

    Murrock, Carolyn J; Bekhet, Abir K

    2016-01-01

    Down through the ages, music has been universally valued for its therapeutic properties based on the psychological and physiological responses in humans. However, the underlying mechanisms of the psychological and physiological responses to music have been poorly identified and defined. Without clarification, a concept can be misused, thereby diminishing its importance for application to nursing research and practice. The purpose of this article was for the clarification of the concept of music therapy based on Walker and Avant's concept analysis strategy. A review of recent nursing and health-related literature covering the years 2007-2014 was performed on the concepts of music, music therapy, preferred music, and individualized music. As a result of the search, the attributes, antecedents, and consequences of music therapy were identified, defined, and used to develop a conceptual model of music therapy. The conceptual model of music therapy provides direction for developing music interventions for nursing research and practice to be tested in various settings to improve various patient outcomes. Based on Walker and Avant's concept analysis strategy, model and contrary cases are included. Implications for future nursing research and practice to use the psychological and physiological responses to music therapy are discussed.

  15. Concept Analysis: Music Therapy.

    PubMed

    Murrock, Carolyn J; Bekhet, Abir K

    2016-01-01

    Down through the ages, music has been universally valued for its therapeutic properties based on the psychological and physiological responses in humans. However, the underlying mechanisms of the psychological and physiological responses to music have been poorly identified and defined. Without clarification, a concept can be misused, thereby diminishing its importance for application to nursing research and practice. The purpose of this article was for the clarification of the concept of music therapy based on Walker and Avant's concept analysis strategy. A review of recent nursing and health-related literature covering the years 2007-2014 was performed on the concepts of music, music therapy, preferred music, and individualized music. As a result of the search, the attributes, antecedents, and consequences of music therapy were identified, defined, and used to develop a conceptual model of music therapy. The conceptual model of music therapy provides direction for developing music interventions for nursing research and practice to be tested in various settings to improve various patient outcomes. Based on Walker and Avant's concept analysis strategy, model and contrary cases are included. Implications for future nursing research and practice to use the psychological and physiological responses to music therapy are discussed. PMID:27024999

  16. [Concepts of anthropological medicine].

    PubMed

    Petzold, E R; Petzold, U

    2001-01-01

    Medical anthropology is the teaching of the ill human being, of being ill; anthropological medicine is the realization of this teaching in practice. This concept was first developed and assessed in the "Gestaltkreis" and in the Pathosophy (44), in Medicine in Motion (39), and in the Bipersonality (10). The four most important concepts are represented, which have their origin and aim in anthropological medicine: anthropological medicine, Balint-work, family-oriented medicine, and salutogenesis. These concepts are exemplified in the Aachen psychosomatic liaison model, the Aachen Balint cooperation model, and the Aachen model of psychosomatic care. We wish to portray the meaning of these resources for the medicine of the future, since they have proven to be effective, cost-saving, and easy to be handled. In the latter part of our presentation, we will document this point with a pilot study conducted in Israel and in our own clinic in Aachen. PMID:11603206

  17. Basic concepts of depression

    PubMed Central

    Paykel, Eugene S.

    2008-01-01

    This paper reviews concepts of depression, including history and classification. The original broad concept of melancholia included all forms of quiet insanity. The term depression began to appear in the nineteenth century as did the modern concept of affective disorders, with the core disturbance now viewed as one of mood. The 1930s saw the introduction of defined criteria into official diagnostic schemes. The modern separation into unipolar and bipolar disorder was introduced following empirical research by Angst and Perris in the 1960s. The partially overlapping distinctions between psychotic and neurotic depression, and between endogenous and reactive depression, started to generate debate in the 1920s, with considerable multivariate research in the 1960s. The symptom element in endogenous depression currently survives in melancholia or somatic syndrome. Life stress is common in various depressive pictures. Dysthymia, a valuable diagnosis, represents a form of what was regarded earlier as neurotic depression. Other subtypes are also discussed. PMID:18979941

  18. Basic concepts of depression.

    PubMed

    Paykel, Eugene S

    2008-01-01

    This paper reviews concepts of depression, including history and classification. The original broad concept of melancholia included all forms of quiet insanity. The term depression began to appear in the nineteenth century, as did the modern concept of affective disorders, with the core disturbance now viewed as one of mood. The 1980s saw the introduction of defined criteria into official diagnostic schemes. The modern separation into unipolar and bipolar disorder was introduced following empirical research by Angst and Perris in the 1960s. The partially overlapping distinctions between psychotic and neurotic depression, and between endogenous and reactive depression, started to generate debate in the 1920s, with considerable multivariate research in the 1960s. The symptom element in endogenous depression currently survives in melancholia or somatic syndrome. Life stress is common in various depressive pictures. Dysthymia, a valuable diagnosis, represents a form of what was regarded earlier as neurotic depression. Other subtypes are also discussed.

  19. Telepresence work system concepts

    NASA Technical Reports Server (NTRS)

    Jenkins, L. M.

    1985-01-01

    Telepresence has been used in the context of the ultimate in remote manipulation where the operator is provided with the sensory feedback and control to perform highly dexterous tasks. The concept of a Telepresence Work Station (TWS) for operation in space is described. System requirements, concepts, and a development approach are discussed. The TWS has the potential for application on the Space Shuttle, on the Orbit Maneuver Vehicle, on an Orbit Transfer Vehicle, and on the Space Station. The TWS function is to perform satellite servicing tasks and construction and assembly operations in the buildup of large spacecraft. The basic concept is a pair of dexterous arms controlled from a remote station by an operation with feedback. It may be evolved through levels of supervisory control to a smart adaptive robotic system.

  20. Mars Rover Concept Development

    NASA Astrophysics Data System (ADS)

    McTamaney, Louis S.; Harmon, Scott Y.

    1989-03-01

    FMC conducted a carefully structured study effort designed to develop an extensive set of mobility and navigation concepts for a planetary exploration vehicle. This focused study commenced with a requirements analysis that defined operational and functional requirements and constraints. Next, the physical system, its value system (evaluation parameters and design criteria) and the martian terrain design environment (surface models) were developed simultaneously. Mobility (the basic vehicle structure, suspension, and power train) and navigation (both global and local navigation including global reference, local terrain assessment, and guidance and control) concepts were developed independently and then integrated. Special attention was paid to the interdependency of navigation and locomotion in order to strike the appropriate balance between autonomy and mobility. Finally, the most promising concepts were subjected to a rigorous, structured evaluation process to derive the best candidate systems. To support the evaluation process, a three-layer computer model of the martian surface was developed. This model was based on the 1/64° Digital Elevation Model (DEM) of Mars developed by USGS Flagstaff. Local surface roughness based on measured martian slope distribution and power spectral density was superimposed on the DEM. Rocks based on H. Moore's distribution model were then added. To assess performance, selected concepts were modeled using DADSR from Computer Aided Software Inc., and simulations were run with the vehicle traversing the martian surface model, including one meter high vertical steps and one meter wide crevasses . During the course of this study, over 300 mobility concepts and more than 400 navigation concepts generated during a series of brainstorming sessions evolved into three promising candidate systems. The evolution of these systems is discussed; design details, conclusions and recommendations are presented.

  1. Revisiting the matricellular concept

    PubMed Central

    Murphy-Ullrich, Joanne E.; Sage, E. Helene

    2015-01-01

    The concept of a matricellular protein was first proposed by Paul Bornstein in the mid-1990s to account for the non-lethal phenotypes of mice with inactivated genes encoding thrombospondin-1, tenascin-C, or SPARC. It was also recognized that these extracellular matrix proteins were primarily counter or de-adhesive. This review reappraises the matricellular concept after nearly two decades of continuous investigation. The expanded matricellular family as well as the diverse and often unexpected functions, cellular location, and interacting partners/receptors of matricellular proteins are considered. Development of therapeutic strategies that target matricellular proteins are discussed in the context of pathology and regenerative medicine. PMID:25064829

  2. [Concepts of rational taxonomy].

    PubMed

    Pavlinov, I Ia

    2011-01-01

    The problems are discussed related to development of concepts of rational taxonomy and rational classifications (taxonomic systems) in biology. Rational taxonomy is based on the assumption that the key characteristic of rationality is deductive inference of certain partial judgments about reality under study from other judgments taken as more general and a priory true. Respectively, two forms of rationality are discriminated--ontological and epistemological ones. The former implies inference of classifications properties from general (essential) properties of the reality being investigated. The latter implies inference of the partial rules of judgments about classifications from more general (formal) rules. The following principal concepts of ontologically rational biological taxonomy are considered: "crystallographic" approach, inference of the orderliness of organismal diversity from general laws of Nature, inference of the above orderliness from the orderliness of ontogenetic development programs, based on the concept of natural kind and Cassirer's series theory, based on the systemic concept, based on the idea of periodic systems. Various concepts of ontologically rational taxonomy can be generalized by an idea of the causal taxonomy, according to which any biologically sound classification is founded on a contentwise model of biological diversity that includes explicit indication of general causes responsible for that diversity. It is asserted that each category of general causation and respective background model may serve as a basis for a particular ontologically rational taxonomy as a distinctive research program. Concepts of epistemologically rational taxonomy and classifications (taxonomic systems) can be interpreted in terms of application of certain epistemological criteria of substantiation of scientific status of taxonomy in general and of taxonomic systems in particular. These concepts include: consideration of taxonomy consistency from the

  3. Teaching power concepts.

    PubMed

    Heineken, J; McCloskey, J C

    1985-01-01

    Concepts and strategies presented here provide nurses with a new perspective from which to analyze and interact with power dynamics. Understanding fundamental concepts of power will help nurses enjoy a more equal status and bargaining position within the community of health professionals and in health care delivery systems. As nurses integrate and utilize this content for enhancing professional practices and client services, our public image will also continue to be strengthened. In so doing, our power base and sphere of influence will also be broadened.

  4. Introduction: Bridging Concepts.

    PubMed

    Davids, Karel

    2015-12-01

    How can those in the history of science, history of technology, and economics communicate more with each other than they are accustomed? How can they become more globally oriented? While these three disciplines today have more convergent interests than in the past, there is still a large potential for further exchange and involvement to explore and exploit. The contributors to this Focus section discuss a number of concepts that may serve as tools to bring these three disciplines more closely together and ease their evolution in a less Eurocentric direction. These concepts include trading zones, interaction and formalization, production, and machines and self-organization. PMID:27024939

  5. Field resonance propulsion concept

    NASA Technical Reports Server (NTRS)

    Holt, A. C.

    1979-01-01

    A propulsion concept was developed based on a proposed resonance between coherent, pulsed electromagnetic wave forms, and gravitational wave forms (or space-time metrics). Using this concept a spacecraft propulsion system potentially capable of galactic and intergalactic travel without prohibitive travel times was designed. The propulsion system utilizes recent research associated with magnetic field line merging, hydromagnetic wave effects, free-electron lasers, laser generation of megagauss fields, and special structural and containment metals. The research required to determine potential, field resonance characteristics and to evaluate various aspects of the spacecraft propulsion design is described.

  6. Revisiting the matricellular concept.

    PubMed

    Murphy-Ullrich, Joanne E; Sage, E Helene

    2014-07-01

    The concept of a matricellular protein was first proposed by Paul Bornstein in the mid-1990s to account for the non-lethal phenotypes of mice with inactivated genes encoding thrombospondin-1, tenascin-C, or SPARC. It was also recognized that these extracellular matrix proteins were primarily counter or de-adhesive. This review reappraises the matricellular concept after nearly two decades of continuous investigation. The expanded matricellular family as well as the diverse and often unexpected functions, cellular location, and interacting partners/receptors of matricellular proteins are considered. Development of therapeutic strategies that target matricellular proteins are discussed in the context of pathology and regenerative medicine.

  7. Introduction: Bridging Concepts.

    PubMed

    Davids, Karel

    2015-12-01

    How can those in the history of science, history of technology, and economics communicate more with each other than they are accustomed? How can they become more globally oriented? While these three disciplines today have more convergent interests than in the past, there is still a large potential for further exchange and involvement to explore and exploit. The contributors to this Focus section discuss a number of concepts that may serve as tools to bring these three disciplines more closely together and ease their evolution in a less Eurocentric direction. These concepts include trading zones, interaction and formalization, production, and machines and self-organization.

  8. [Learning in online education: analysis of concept].

    PubMed

    de Holanda, Viviane Rolim; Pinheiro, Ana Karina Bezerra; Pagliuca, Lorita Marlena Freitag

    2013-01-01

    This work aimed at clarifying the concept learning in online education, expressed by the literature in the area of health. It is a study of analysis of concept, based on the Evolutionary Model, being highlighted attributes, background, consequents and substitute terms. Learning in the context of online education is characterized by a dynamic and continuous process of active construction of knowledge and acquisition of skills, with physical separation between students and teachers. Among the background events discussed stood out: interest and motivation in learning; dedication and time self-management; and interaction and communication tools. The main evident consequents were: student's autonomy; independent and active study; and construction of own knowledge. The prevailing substitute terms were collaborative learning and self-learning. The understanding of the concept can contribute to its implementation in nursing teaching activities in virtual environments. PMID:23887791

  9. [Learning in online education: analysis of concept].

    PubMed

    de Holanda, Viviane Rolim; Pinheiro, Ana Karina Bezerra; Pagliuca, Lorita Marlena Freitag

    2013-01-01

    This work aimed at clarifying the concept learning in online education, expressed by the literature in the area of health. It is a study of analysis of concept, based on the Evolutionary Model, being highlighted attributes, background, consequents and substitute terms. Learning in the context of online education is characterized by a dynamic and continuous process of active construction of knowledge and acquisition of skills, with physical separation between students and teachers. Among the background events discussed stood out: interest and motivation in learning; dedication and time self-management; and interaction and communication tools. The main evident consequents were: student's autonomy; independent and active study; and construction of own knowledge. The prevailing substitute terms were collaborative learning and self-learning. The understanding of the concept can contribute to its implementation in nursing teaching activities in virtual environments.

  10. Innatism, Concept Formation, Concept Mastery and Formal Education

    ERIC Educational Resources Information Center

    Winch, Christopher

    2015-01-01

    This article will consider the claim that the possession of concepts is innate rather than learned. Innatism about concept learning is explained through consideration of the work of Fodor and Chomsky. First, an account of concept formation is developed. Second the argument against the claim that concepts are learned through the construction of a…

  11. Understanding the Agribusiness Concept.

    ERIC Educational Resources Information Center

    Lee, Jasper S.

    Designed to aid in learning the main ideas of the agribusiness concept, this document answers the following questions, treating each answer in a separate explanatory section: (1) What is the meaning of the terms "agriculture" and "agribusiness"? (2) What is the relationship of agriculture and agribusiness? (3) What is involved in tracing an…

  12. The Concept of Intelligence

    ERIC Educational Resources Information Center

    Hand, Michael

    2007-01-01

    Analyses of the ordinary concept of intelligence are few and far between in philosophical literature. Such analyses as there have been in recent years are heavily influenced by Ryle's suggestion that to act intelligently is to act "well" or "competently" in a particular domain. Here I show that there are serious problems with Ryle's account and…

  13. Team Building Concepts.

    ERIC Educational Resources Information Center

    Massachusetts Career Development Inst., Springfield.

    This booklet is one of six texts from a workplace literacy curriculum designed to assist learners in facing the increased demands of the workplace. It briefly explains how team building concepts affect businesses in new ways and how they help create an environment that provides job satisfaction for everyone and high-quality products for the…

  14. Some Core Contested Concepts

    ERIC Educational Resources Information Center

    Chomsky, Noam

    2015-01-01

    Core concepts of language are highly contested. In some cases this is legitimate: real empirical and conceptual issues arise. In other cases, it seems that controversies are based on misunderstanding. A number of crucial cases are reviewed, and an approach to language is outlined that appears to have strong conceptual and empirical motivation, and…

  15. The Mole Concept

    ERIC Educational Resources Information Center

    Duncan, I. M.; Johnstone, A. H.

    1973-01-01

    Reports a study of difficulties encountered by 14.5- to 15.0- year-old children in learning the mole concept with a programed instruction. Concludes that three respective disturbing factors were embedded in manipulation of molarity of solutions, balancing equations, and misapprehension that one mole of a compound always reacts with one mole of…

  16. Teaching Weather Concepts.

    ERIC Educational Resources Information Center

    Sebastian, Glenn R.

    Ten exercises based on the weather map provided in the national newspaper "U.S.A. Today" are used to teach intermediate grade students about weather. An overview describes the history of "U.S.A. Today," the format of the newspaper's weather map, and the map's suitability for teaching weather concepts. Specific exercises, which are briefly…

  17. Using Concept Cartoons

    ERIC Educational Resources Information Center

    Dabell, John

    2008-01-01

    Concept cartoons are cognitive drawings or "visual disagreements" that use a cartoon-style design to present mathematical conversations inside speech bubbles. The viewpoints portrayed are all different and it is this difference that acts as a catalyst for further conversations, as learners talk together to discuss their thinking. They make…

  18. Concept-Based Learning

    ERIC Educational Resources Information Center

    Schill, Bethany; Howell, Linda

    2011-01-01

    A major part of developing concept-based instruction is the use of an overarching idea to provide a conceptual lens through which students view the content of a particular subject. By using a conceptual lens to focus learning, students think at a much deeper level about the content and its facts (Erickson 2007). Therefore, the authors collaborated…

  19. Networks of Emotion Concepts

    PubMed Central

    Toivonen, Riitta; Kivelä, Mikko; Saramäki, Jari; Viinikainen, Mikko; Vanhatalo, Maija; Sams, Mikko

    2012-01-01

    The aim of this work was to study the similarity network and hierarchical clustering of Finnish emotion concepts. Native speakers of Finnish evaluated similarity between the 50 most frequently used Finnish words describing emotional experiences. We hypothesized that methods developed within network theory, such as identifying clusters and specific local network structures, can reveal structures that would be difficult to discover using traditional methods such as multidimensional scaling (MDS) and ordinary cluster analysis. The concepts divided into three main clusters, which can be described as negative, positive, and surprise. Negative and positive clusters divided further into meaningful sub-clusters, corresponding to those found in previous studies. Importantly, this method allowed the same concept to be a member in more than one cluster. Our results suggest that studying particular network structures that do not fit into a low-dimensional description can shed additional light on why subjects evaluate certain concepts as similar. To encourage the use of network methods in analyzing similarity data, we provide the analysis software for free use (http://www.becs.tkk.fi/similaritynets/). PMID:22276099

  20. Two Conceptions of Virtue

    ERIC Educational Resources Information Center

    Hill, Thomas E., Jr.

    2013-01-01

    The general questions are: what is virtue and how can it be cultivated? The specific focus is on the conceptions of virtue in the works of Immanuel Kant and John Rawls. Kant regarded virtue as a good will that is also strong enough to resist contrary passions, impulses, and inclinations. Childhood training can prepare children for virtue, but…