Science.gov

Sample records for physics model investigation

  1. Investigations of physical model of biological tissue

    NASA Astrophysics Data System (ADS)

    Linkov, Kirill G.; Kisselev, Gennady L.; Loschenov, Victor B.

    1996-12-01

    Physical model of a biological tissue for comparison with earlier created mathematical model of a biological tissue and researches of distribution photosensitizer in a depth was created and investigated. Mathematical model is based on granulated representation of optical medium. The model of a biological tissue was created on the basis of enough thin layers of a special material. For fluorescence excitation laser sources with a various wavelength were used. For investigation of scattering and fluorescent signal laser- fiber spectrum-analyzer LESA-5 was applied. Water solution of aluminum phthalocyanine and oil solution of zinc phthalocyanine were used for receiving of fluorescent signal. Created samples have certain absorbing and fluorescent properties. Scattering properties of samples are close to scattering properties of real human skin. By virtue of layered structure the model permits to simulate as a biological tissue without photosensitizer accumulation in it, as tissue with photosensitizer accumulation with certain distribution in a depth. Dependence of fields distribution on a surface was investigated at change of parameters of a model. Essential changes of distribution on a surface depending on the characteristics of model was revealed. The space and angular characteristics was investigated also. The investigations with physical model correspond to predicted results of theoretical model.

  2. Investigating Student Understanding of Quantum Physics: Spontaneous Models of Conductivity.

    ERIC Educational Resources Information Center

    Wittmann, Michael C.; Steinberg, Richard N.; Redish, Edward F.

    2002-01-01

    Investigates student reasoning about models of conduction. Reports that students often are unable to account for the existence of free electrons in a conductor and create models that lead to incorrect predictions and responses contradictory to expert descriptions of the physics involved. (Contains 36 references.) (Author/YDS)

  3. Investigating Student Understanding of Quantum Physics: Spontaneous Models of Conductivity.

    ERIC Educational Resources Information Center

    Wittmann, Michael C.; Steinberg, Richard N.; Redish, Edward F.

    2002-01-01

    Investigates student reasoning about models of conduction. Reports that students often are unable to account for the existence of free electrons in a conductor and create models that lead to incorrect predictions and responses contradictory to expert descriptions of the physics involved. (Contains 36 references.) (Author/YDS)

  4. Preliminary Investigation of Microdosimetric Track Structure Physics Models in Geant4-DNA and RITRACKS

    PubMed Central

    Bezak, Eva

    2015-01-01

    The major differences between the physics models in Geant4-DNA and RITRACKS Monte Carlo packages are investigated. Proton and electron ionisation interactions and electron excitation interactions in water are investigated in the current work. While these packages use similar semiempirical physics models for inelastic cross-sections, the implementation of these models is demonstrated to be significantly different. This is demonstrated in a simple Monte Carlo simulation designed to identify differences in interaction cross-sections. PMID:26124856

  5. Voice outcomes following laser cordectomy for early glottic cancer: a physical model investigation.

    PubMed

    Mendelsohn, Abie H; Xuan, Yue; Zhang, Zhaoyan

    2014-08-01

    The voice effects following laser cordectomy for early glottic cancer are poorly described. We investigated the voice outcomes of subligamentous cordectomy of progressive anterior-posterior extent of excision. Physical phonatory modeling. The influence of vocal fold surgical defects and corresponding scar was experimentally investigated using a self-oscillating physical model of the vocal folds and compared with the baseline model without defects or scar. Results showed that increasing anterior-posterior extent of resection increased phonation threshold pressure and flow rate and reduced excitation of high-order harmonics, resulting in a more breathy and rough voice production. However, it was found that voice production was improved with the placement of scar, which increased both excitation of high-order harmonics and the harmonic-to-noise ratio. Although large anterior-posterior surgical resections resulted in progressive impact on vocal measures, a limited excision of the vocal fold cover surprisingly demonstrated minimal voice changes. Further investigations are required to define the acceptable extent of surgical resection that may result in optimal voice outcomes. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

  6. Investigation of Pupils' Levels of MVPA and VPA during Physical Education Units Focused on Direct Instruction and Tactical Games Models

    ERIC Educational Resources Information Center

    Harvey, Stephen; Smith, Lindsey; Fairclough, Stuart; Savory, Louise; Kerr, Catherine

    2015-01-01

    We investigated the moderate to vigorous physical activity (MVPA) and vigorous physical activity (VPA) levels of pupils during coeducational physical education units focused on direct instruction and tactical games models (TGM). Thirty-two children (11-12 years, 17 girls) were randomly assigned to either a direct instruction (control) or TGM…

  7. Investigation of Pupils' Levels of MVPA and VPA during Physical Education Units Focused on Direct Instruction and Tactical Games Models

    ERIC Educational Resources Information Center

    Harvey, Stephen; Smith, Lindsey; Fairclough, Stuart; Savory, Louise; Kerr, Catherine

    2015-01-01

    We investigated the moderate to vigorous physical activity (MVPA) and vigorous physical activity (VPA) levels of pupils during coeducational physical education units focused on direct instruction and tactical games models (TGM). Thirty-two children (11-12 years, 17 girls) were randomly assigned to either a direct instruction (control) or TGM…

  8. A longitudinal investigation of older adults' physical activity: Testing an integrated dual-process model.

    PubMed

    Arnautovska, Urska; Fleig, Lena; O'Callaghan, Frances; Hamilton, Kyra

    2017-02-01

    To assess the effects of conscious and non-conscious processes for prediction of older adults' physical activity (PA), we tested a dual-process model that integrated motivational (behavioural intention) and volitional (action planning and coping planning) processes with non-conscious, automatic processes (habit). Participants (N = 215) comprised community-dwelling older adults (M = 73.8 years). A longitudinal design was adopted to investigate direct and indirect effects of intentions, habit strength (Time 1), and action planning and coping planning (Time 2) on PA behaviour (Time 3). Structural equation modelling was used to evaluate the model. The model provided a good fit to the data, accounting for 44% of the variance in PA behaviour at Time 3. PA was predicted by intentions, action planning, and habit strength, with action planning mediating the intention-behaviour relationship. An effect of sex was also found where males used fewer planning strategies and engaged in more PA than females. By investigating an integration of conscious and non-conscious processes, this study provides a novel understanding of older adults' PA. Interventions aiming to promote PA behaviour of older adults should target the combination of psychological processes.

  9. Advancing investigation and physical modeling of first-order fire effects on soils

    Treesearch

    William J. Massman; John M. Frank; Sacha J. Mooney

    2010-01-01

    Heating soil during intense wildland fires or slash-pile burns can alter the soil irreversibly, resulting in many significant long-term biological, chemical, physical, and hydrological effects. To better understand these long-term effects, it is necessary to improve modeling capability and prediction of the more immediate, or first-order, effects that fire can have on...

  10. Physical modelling in biomechanics.

    PubMed Central

    Koehl, M A R

    2003-01-01

    Physical models, like mathematical models, are useful tools in biomechanical research. Physical models enable investigators to explore parameter space in a way that is not possible using a comparative approach with living organisms: parameters can be varied one at a time to measure the performance consequences of each, while values and combinations not found in nature can be tested. Experiments using physical models in the laboratory or field can circumvent problems posed by uncooperative or endangered organisms. Physical models also permit some aspects of the biomechanical performance of extinct organisms to be measured. Use of properly scaled physical models allows detailed physical measurements to be made for organisms that are too small or fast to be easily studied directly. The process of physical modelling and the advantages and limitations of this approach are illustrated using examples from our research on hydrodynamic forces on sessile organisms, mechanics of hydraulic skeletons, food capture by zooplankton and odour interception by olfactory antennules. PMID:14561350

  11. Physics in Police Investigations.

    ERIC Educational Resources Information Center

    Young, Peter

    1980-01-01

    Described are several techniques and pieces of equipment developed by the Police Scientific Department Branch in its application of physics to police problems. Topics discussed include fingerprints, documents, and photographs. (Author/DS)

  12. Physics in Police Investigations.

    ERIC Educational Resources Information Center

    Young, Peter

    1980-01-01

    Described are several techniques and pieces of equipment developed by the Police Scientific Department Branch in its application of physics to police problems. Topics discussed include fingerprints, documents, and photographs. (Author/DS)

  13. Physics in Accident Investigations.

    ERIC Educational Resources Information Center

    Brake, Mary L.

    1981-01-01

    Describes physics formulas which can be used by law enforcement officials to determine the possible velocity of vehicles involved in traffic accidents. These include, among others, the slide to stop-level road, slide to stop-sloping roadway, and slide to stop-two different surfaces formulas. (JN)

  14. Computational investigations on polymerase actions in gene transcription and replication: Combining physical modeling and atomistic simulations

    NASA Astrophysics Data System (ADS)

    Jin, Yu

    2016-01-01

    Polymerases are protein enzymes that move along nucleic acid chains and catalyze template-based polymerization reactions during gene transcription and replication. The polymerases also substantially improve transcription or replication fidelity through the non-equilibrium enzymatic cycles. We briefly review computational efforts that have been made toward understanding mechano-chemical coupling and fidelity control mechanisms of the polymerase elongation. The polymerases are regarded as molecular information motors during the elongation process. It requires a full spectrum of computational approaches from multiple time and length scales to understand the full polymerase functional cycle. We stay away from quantum mechanics based approaches to the polymerase catalysis due to abundant former surveys, while addressing statistical physics modeling approaches along with all-atom molecular dynamics simulation studies. We organize this review around our own modeling and simulation practices on a single subunit T7 RNA polymerase, and summarize commensurate studies on structurally similar DNA polymerases as well. For multi-subunit RNA polymerases that have been actively studied in recent years, we leave systematical reviews of the simulation achievements to latest computational chemistry surveys, while covering only representative studies published very recently, including our own work modeling structure-based elongation kinetic of yeast RNA polymerase II. In the end, we briefly go through physical modeling on elongation pauses and backtracking activities of the multi-subunit RNAPs. We emphasize on the fluctuation and control mechanisms of the polymerase actions, highlight the non-equilibrium nature of the operation system, and try to build some perspectives toward understanding the polymerase impacts from the single molecule level to a genome-wide scale. Project supported by the National Natural Science Foundation (Grant No. 11275022).

  15. Physics of the upper atmosphere: Series B - Theoretical models and results of investigations

    NASA Astrophysics Data System (ADS)

    Ivanovskii, A. I.

    The papers contained in this volume provide an overview of recent theoretical research in the physics of the upper atmosphere and analysis of processes occurring in the stratosphere, mesosphere, and lower thermosphere. Topics discussed include the meridional structure of stationary planetary waves in the middle atmosphere; a model kinetic equation for describing free molecular flows in capillaries; analysis of long-period oscillations of atmospheric parameters in the tropical zone; and some characteristics of ozone distribution in the winter periods of 1983/84 and 1984/85. Papers are also presented on natural and anthropogenic sources of ozone-active compounds in the atmosphere and on the variability of the temperature and geopotential heights of isobaric surfaces in the tropical stratosphere of the Northern Hemisphere.

  16. Investigation of the Sound Pressure Level (SPL) of earphones during music listening with the use of physical ear canal models

    NASA Astrophysics Data System (ADS)

    Aying, K. P.; Otadoy, R. E.; Violanda, R.

    2015-06-01

    This study investigates on the sound pressure level (SPL) of insert-type earphones that are commonly used for music listening of the general populace. Measurements of SPL from earphones of different respondents were measured by plugging the earphone to a physical ear canal model. Durations of the earphone used for music listening were also gathered through short interviews. Results show that 21% of the respondents exceed the standard loudness/duration relation recommended by the World Health Organization (WHO).

  17. Time Dependent Magnesium AZ31B Behavior: Experimental and Physically based Modeling Investigation

    NASA Astrophysics Data System (ADS)

    Rodriguez, A. K.; Ayoub, G.; Kridli, G.; Zbib, H.

    The need to produce vehicles with improved fuel efficiency and reduced emissions has led the automotive industry to consider use of "lightweighting" materials in the construction of automotive body and chassis systems. For automotive body structures and closure panel applications, mostly made of sheet, aluminum alloys are being introduced due to their lower densities and relatively high specific strengths, as well as their compatibility with the traditional manufacturing process that are used with steel. However, interest has been increasingly focusing on the use of sheet magnesium in the manufacturing of panels and structural components, since its density is about 40% lower compared to aluminum. Accordingly, the objectives of this study are to investigate the evolution of microstructure during thermo-mechanical processing of twin-roll cast AZ31B alloys sheets, and to examine the mechanical properties of the alloy under superplastic conditions. The rate dependent crystal plasticity model have been used and integrated using an explicit model was coupled with the Taylor polycrystal model in the aim to capture the overall behavior of our studied material.

  18. Investigation and identification of physical mechanism for enhanced thermal conductivity in nanofluids using molecular level modeling

    NASA Astrophysics Data System (ADS)

    Evans, William John

    Over the last decade a significant research effort has been committed to exploring the thermal transport properties of colloidal suspensions of nanosized solid particles (nanofluids). Initial experiments with Cu-water nanofluids measured up to a 40% increase in thermal conductivity for a mere 0.3% volume fraction of ˜10 nanometer (nm) diameter Cu particles. This increase is significantly larger than predicted by effective medium theory (EMT) of a composite material comprised of well dispersed particles. However, other experimental work on various compositions of nanoparticles and fluids has demonstrated thermal conductivity increases more in line with EMT. A number of possible origins for such behavior have been proposed, but a consensus has yet to emerge. More of the literature attempts to find correlations based on EMT that fit the experimental data rather than exploring the underlying mechanism. The likely candidate theories of liquid layering at the particle-fluid interface, Brownian motion induced heat transfer and particle aggregation are thoroughly explored in this thesis. We undertake a systematic investigation of these most likely mechanisms for enhanced thermal conductivity in nanofluids utilizing various analytical modeling techniques including equilibrium and non-equilibrium molecular dynamics (MD). We demonstrate that aggregation of nanoparticles is the most likely mechanism for enhanced thermal conductivity. We also include the effect of Kapitza interfacial resistance and aggregate shape on nanofluid thermal conductivity. Using our aggregate models, we investigate nanofluid viscosity. Nanoparticle clusters are shown to increase the nanofluid viscosity by up to 75% at 5% volume fraction. Overall the nanofluid exhibits shear thinning behavior.

  19. Development of in vitro models for investigating spatially fractionated irradiation: physics and biological results

    NASA Astrophysics Data System (ADS)

    Blockhuys, S; Vanhoecke, B; Paelinck, L; Bracke, M; DeWagter, C

    2009-03-01

    We present different in vitro experimental models which allow us to evaluate the effect of spatially fractionated dose distributions on metabolic activity. We irradiated a monolayer of MCF-7/6 human breast cancer cells with a steep and a smooth 6 MV x-ray dose gradient. In the steep gradient model, we irradiated the cells with three separate small fields. We also developed two smooth gradient models. In the first model, the cells are cultured in a T25 flask and irradiated with a smooth dose gradient over the length of the flask, while in the second one, the cells are cultured in a 96-well plate and also irradiated over the length of the plate. In an attempt to correlate the spatially fractionated dose distributions with metabolic activity, the effect of irradiation was evaluated by means of the MTT assay. This assay is used to determine the metabolic activity by measuring the amount of formazan formed after the conversion of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) by cellular dehydrogenases. The results obtained with our different models suggest a dose-specific effect on metabolic activity, characterized by an increased formazan optical density occurring in the dose range 1.0-4.0 Gy in the steep dose gradient model and in the dose ranges 4.2-6.5 Gy and 2.3-5.1 Gy in the two smooth dose gradient models. The corresponding times for maximal formazan accumulation were 5-7 days in the steep dose gradient model and day 9-13 and day 9-11 in the smooth dose gradient models. Altogether, our results suggest that the MTT assay may be used as a biological dose-response meter to monitor the radiotherapeutic effectiveness.

  20. Interactive locomotion: Investigation and modeling of physically-paired humans while walking

    PubMed Central

    Le Goff, Camille G.; Ijspeert, Auke Jan

    2017-01-01

    In spite of extensive studies on human walking, less research has been conducted on human walking gait adaptation during interaction with another human. In this paper, we study a particular case of interactive locomotion where two humans carry a rigid object together. Experimental data from two persons walking together, one in front of the other, while carrying a stretcher-like object is presented, and the adaptation of their walking gaits and coordination of the foot-fall patterns are analyzed. It is observed that in more than 70% of the experiments the subjects synchronize their walking gaits; it is shown that these walking gaits can be associated to quadrupedal gaits. Moreover, in order to understand the extent by which the passive dynamics can explain this synchronization behaviour, a simple 2D model, made of two-coupled spring-loaded inverted pendulums, is developed, and a comparison between the experiments and simulations with this model is presented, showing that with this simple model we are able to reproduce some aspects of human walking behaviour when paired with another human. PMID:28877161

  1. A decision tree algorithm for investigation of model biases related to dynamical cores and physical parameterizations

    PubMed Central

    Rood, Richard B.

    2016-01-01

    Abstract An object‐based evaluation method using a pattern recognition algorithm (i.e., classification trees) is applied to the simulated orographic precipitation for idealized experimental setups using the National Center of Atmospheric Research (NCAR) Community Atmosphere Model (CAM) with the finite volume (FV) and the Eulerian spectral transform dynamical cores with varying resolutions. Daily simulations were analyzed and three different types of precipitation features were identified by the classification tree algorithm. The statistical characteristics of these features (i.e., maximum value, mean value, and variance) were calculated to quantify the difference between the dynamical cores and changing resolutions. Even with the simple and smooth topography in the idealized setups, complexity in the precipitation fields simulated by the models develops quickly. The classification tree algorithm using objective thresholding successfully detected different types of precipitation features even as the complexity of the precipitation field increased. The results show that the complexity and the bias introduced in small‐scale phenomena due to the spectral transform method of CAM Eulerian spectral dynamical core is prominent, and is an important reason for its dissimilarity from the FV dynamical core. The resolvable scales, both in horizontal and vertical dimensions, have significant effect on the simulation of precipitation. The results of this study also suggest that an efficient and informative study about the biases produced by GCMs should involve daily (or even hourly) output (rather than monthly mean) analysis over local scales. PMID:28239437

  2. A decision tree algorithm for investigation of model biases related to dynamical cores and physical parameterizations.

    PubMed

    Soner Yorgun, M; Rood, Richard B

    2016-12-01

    An object-based evaluation method using a pattern recognition algorithm (i.e., classification trees) is applied to the simulated orographic precipitation for idealized experimental setups using the National Center of Atmospheric Research (NCAR) Community Atmosphere Model (CAM) with the finite volume (FV) and the Eulerian spectral transform dynamical cores with varying resolutions. Daily simulations were analyzed and three different types of precipitation features were identified by the classification tree algorithm. The statistical characteristics of these features (i.e., maximum value, mean value, and variance) were calculated to quantify the difference between the dynamical cores and changing resolutions. Even with the simple and smooth topography in the idealized setups, complexity in the precipitation fields simulated by the models develops quickly. The classification tree algorithm using objective thresholding successfully detected different types of precipitation features even as the complexity of the precipitation field increased. The results show that the complexity and the bias introduced in small-scale phenomena due to the spectral transform method of CAM Eulerian spectral dynamical core is prominent, and is an important reason for its dissimilarity from the FV dynamical core. The resolvable scales, both in horizontal and vertical dimensions, have significant effect on the simulation of precipitation. The results of this study also suggest that an efficient and informative study about the biases produced by GCMs should involve daily (or even hourly) output (rather than monthly mean) analysis over local scales.

  3. Investigating Shear Wave Physics in a Generic Pediatric Left Ventricular Model via In Vitro Experiments and Finite Element Simulations.

    PubMed

    Caenen, Annette; Pernot, Mathieu; Shcherbakova, Darya Alexandrovna; Mertens, Luc; Kersemans, Mathias; Segers, Patrick; Swillens, Abigail

    2017-02-01

    Shear wave elastography (SWE) is a potentially valuable tool to noninvasively assess ventricular function in children with cardiac disorders, which could help in the early detection of abnormalities in muscle characteristics. Initial experiments demonstrated the potential of this technique in measuring ventricular stiffness; however, its performance remains to be validated as complicated shear wave (SW) propagation characteristics are expected to arise due to the complex non-homogenous structure of the myocardium. In this work, we investigated the (i) accuracy of different shear modulus estimation techniques (time-of-flight (TOF) method and phase velocity analysis) across myocardial thickness and (ii) effect of the ventricular geometry, surroundings, acoustic loading, and material viscoelasticity on SW physics. A generic pediatric (10-15-year old) left ventricular model was studied numerically and experimentally. For the SWE experiments, a polyvinylalcohol replicate of the cardiac geometry was fabricated and SW acquisitions were performed on different ventricular areas using varying probe orientations. Additionally, the phantom's stiffness was obtained via mechanical tests. The results of the SWE experiments revealed the following trends for stiffness estimation across the phantom's thickness: a slight stiffness overestimation for phase speed analysis and a clear stiffness underestimation for the TOF method for all acquisitions. The computational model provided valuable 3-D insights in the physical factors influencing SW patterns, especially the surroundings (water), interface force, and viscoelasticity. In conclusion, this paper presents a validation study of two commonly used shear modulus estimators for different ventricular locations and the essential role of SW modeling in understanding SW physics in the pediatric myocardium.

  4. Advanced Propulsion Physics Lab: Eagleworks Investigations

    NASA Technical Reports Server (NTRS)

    Scogin, Tyler

    2014-01-01

    Eagleworks Laboratory is an advanced propulsions physics laboratory with two primary investigations currently underway. The first is a Quantum Vacuum Plasma Thruster (QVPT or Q-thrusters), an advanced electric propulsion technology in the development and demonstration phase. The second investigation is in Warp Field Interferometry (WFI). This is an investigation of Dr. Harold "Sonny" White's theoretical physics models for warp field equations using optical experiments in the Electro Optical laboratory (EOL) at Johnson Space Center. These investigations are pursuing technology necessary to enable human exploration of the solar system and beyond.

  5. Physical analog (centrifuge) model investigation of contrasting structural styles in the Salt Range and Potwar Plateau, northern Pakistan

    NASA Astrophysics Data System (ADS)

    Faisal, Shah; Dixon, John M.

    2015-08-01

    We use scaled physical analog (centrifuge) modeling to investigate along- and across-strike structural variations in the Salt Range and Potwar Plateau of the Himalayan foreland fold-thrust belt of Pakistan. The models, composed of interlayered plasticine and silicone putty laminae, comprise four mechanical units representing the Neoproterozoic Salt Range Formation (basal detachment), Cambrian-Eocene carapace sequence, and Rawalpindi and Siwalik Groups (Neogene molasse), on a rigid base representing the Indian craton. Pre-cut ramps simulate basement faults with various structural geometries. A pre-existing north-dipping basement normal fault under the model foreland induces a frontal ramp and a prominent fault-bend-fold culmination, simulating the Salt Range. The ramp localizes displacement on a frontal thrust that occurs out-of-sequence with respect to other foreland folds and thrusts. With a frontal basement fault terminating to the east against a right-stepping, east-dipping lateral ramp, deformation propagates further south in the east; strata to the east of the lateral ramp are telescoped in ENE-trending detachment folds, fault-propagation folds and pop-up structures above a thick basal detachment (Salt Range Formation), in contrast to translated but less-deformed strata with E-W-trending Salt-Range structures to the west. The models are consistent with Salt Range-Potwar Plateau structural style contrasts being due to basement fault geometry and variation in detachment thickness.

  6. Experimental Investigation of the Anisotropic Mechanical Properties of a Columnar Jointed Rock Mass: Observations from Laboratory-Based Physical Modelling

    NASA Astrophysics Data System (ADS)

    Ji, H.; Zhang, J. C.; Xu, W. Y.; Wang, R. B.; Wang, H. L.; Yan, L.; Lin, Z. N.

    2017-07-01

    Because of the complex geological structure, determination of the field mechanical parameters of the columnar jointed rock mass (CJRM) was a challenging task in the design and construction of the Baihetan hydropower plant. To model the mechanical behaviour of the CJRM, uniaxial compression tests were conducted on artificial CJRM specimens with geological structure similar to that found in the actual CJRM. Based on the test results, the anisotropic deformation and strength were mainly analysed. The empirical correlations of evaluating the field mechanical parameters were derived based on the joint factor approach and the modulus reduction factor method. The findings of the physical model tests were then used to estimate the field moduli and unconfined compressive strengths of the Baihetan CJRM. The results predicted by physical model tests were compared with those obtained from the field tests and the RMR classification system. It is concluded that physical model tests were capable of providing valuable estimations on the field mechanical parameters of the CJRM.

  7. Investigating links between climate and orography in the central Andes: Coupling erosion and precipitation using a physical-statistical model

    NASA Astrophysics Data System (ADS)

    Lowman, Lauren E. L.; Barros, Ana P.

    2014-06-01

    Prior studies evaluated the interplay between climate and orography by investigating the sensitivity of relief to precipitation using the stream power erosion law (SPEL) for specified erosion rates. Here we address the inverse problem, inferring realistic spatial distributions of erosion rates for present-day topography and contemporaneous climate forcing. In the central Andes, similarities in the altitudinal distribution and density of first-order stream outlets and precipitation suggest a direct link between climate and fluvial erosion. Erosion rates are estimated with a Bayesian physical-statistical model based on the SPEL applied at spatial scales that capture joint hydrogeomorphic and hydrometeorological patterns within five river basins and one intermontane basin in Peru and Bolivia. Topographic slope and area data were generated from a high-resolution (˜90 m) digital elevation map, and mean annual precipitation was derived from 14 years of Tropical Rainfall Measuring Mission 3B42v.7 product and adjusted with rain gauge data. Estimated decadal-scale erosion rates vary between 0.68 and 11.59 mm/yr, with basin averages of 2.1-8.5 mm/yr. Even accounting for uncertainty in precipitation and simplifying assumptions, these values are 1-2 orders of magnitude larger than most millennial and million year timescale estimates in the central Andes, using various geological dating techniques (e.g., thermochronology and cosmogenic nuclides), but they are consistent with other decadal-scale estimates using landslide mapping and sediment flux observations. The results also reveal a pattern of spatially dependent erosion consistent with basin hypsometry. The modeling framework provides a means of remotely estimating erosion rates and associated uncertainties under current climate conditions over large regions. 2014. American Geophysical Union. All Rights Reserved.

  8. Numerical investigation of the physical model of a high-power electromagnetic wave in a magnetically insulated transmission line

    NASA Astrophysics Data System (ADS)

    Samokhin, A. A.

    2010-02-01

    An efficient numerical code for simulating the propagation of a high-power electromagnetic pulse in a vacuum transmission line is required to study the physical phenomena occurring in such a line, to analyze the operation of present-day megavolt generators at an ˜10-TW power level, and to design such new devices. The main physical theoretical principles are presented, and the stability of flows in the near-threshold region at the boundary of the regime of magnetic self-insulation is investigated based on one-dimensional telegraph equations with electron losses. Numerical (difference) methods—specifically, a method of characteristics and a finite-difference scheme—are described and their properties and effectiveness are compared by analyzing the high-frequency modes.

  9. Numerical investigation of the physical model of a high-power electromagnetic wave in a magnetically insulated transmission line

    SciTech Connect

    Samokhin, A. A.

    2010-02-15

    An efficient numerical code for simulating the propagation of a high-power electromagnetic pulse in a vacuum transmission line is required to study the physical phenomena occurring in such a line, to analyze the operation of present-day megavolt generators at an {approx}10-TW power level, and to design such new devices. The main physical theoretical principles are presented, and the stability of flows in the near-threshold region at the boundary of the regime of magnetic self-insulation is investigated based on one-dimensional telegraph equations with electron losses. Numerical (difference) methods-specifically, a method of characteristics and a finite-difference scheme-are described and their properties and effectiveness are compared by analyzing the high-frequency modes.

  10. Investigating How German Biology Teachers Use Three-Dimensional Physical Models in Classroom Instruction: a Video Study

    NASA Astrophysics Data System (ADS)

    Werner, Sonja; Förtsch, Christian; Boone, William; von Kotzebue, Lena; Neuhaus, Birgit J.

    2017-07-01

    To obtain a general understanding of science, model use as part of National Education Standards is important for instruction. Model use can be characterized by three aspects: (1) the characteristics of the model, (2) the integration of the model into instruction, and (3) the use of models to foster scientific reasoning. However, there were no empirical results describing the implementation of National Education Standards in science instruction concerning the use of models. Therefore, the present study investigated the implementation of different aspects of model use in German biology instruction. Two biology lessons on the topic neurobiology in grade nine of 32 biology teachers were videotaped (N = 64 videos). These lessons were analysed using an event-based coding manual according to three aspects of model described above. Rasch analysis of the coded categories was conducted and showed reliable measurement. In the first analysis, we identified 68 lessons where a total of 112 different models were used. The in-depth analysis showed that special aspects of an elaborate model use according to several categories of scientific reasoning were rarely implemented in biology instruction. A critical reflection of the used model (N = 25 models; 22.3%) and models to demonstrate scientific reasoning (N = 26 models; 23.2%) were seldom observed. Our findings suggest that pre-service biology teacher education and professional development initiatives in Germany have to focus on both aspects.

  11. Investigation for improving Global Positioning System (GPS) orbits using a discrete sequential estimator and stochastic models of selected physical processes

    NASA Technical Reports Server (NTRS)

    Goad, Clyde C.; Chadwell, C. David

    1993-01-01

    GEODYNII is a conventional batch least-squares differential corrector computer program with deterministic models of the physical environment. Conventional algorithms were used to process differenced phase and pseudorange data to determine eight-day Global Positioning system (GPS) orbits with several meter accuracy. However, random physical processes drive the errors whose magnitudes prevent improving the GPS orbit accuracy. To improve the orbit accuracy, these random processes should be modeled stochastically. The conventional batch least-squares algorithm cannot accommodate stochastic models, only a stochastic estimation algorithm is suitable, such as a sequential filter/smoother. Also, GEODYNII cannot currently model the correlation among data values. Differenced pseudorange, and especially differenced phase, are precise data types that can be used to improve the GPS orbit precision. To overcome these limitations and improve the accuracy of GPS orbits computed using GEODYNII, we proposed to develop a sequential stochastic filter/smoother processor by using GEODYNII as a type of trajectory preprocessor. Our proposed processor is now completed. It contains a correlated double difference range processing capability, first order Gauss Markov models for the solar radiation pressure scale coefficient and y-bias acceleration, and a random walk model for the tropospheric refraction correction. The development approach was to interface the standard GEODYNII output files (measurement partials and variationals) with software modules containing the stochastic estimator, the stochastic models, and a double differenced phase range processing routine. Thus, no modifications to the original GEODYNII software were required. A schematic of the development is shown. The observational data are edited in the preprocessor and the data are passed to GEODYNII as one of its standard data types. A reference orbit is determined using GEODYNII as a batch least-squares processor and the

  12. Investigating ice cliff evolution and contribution to glacier mass-balance using a physically-based dynamic model

    NASA Astrophysics Data System (ADS)

    Buri, Pascal; Miles, Evan; Ragettli, Silvan; Brun, Fanny; Steiner, Jakob; Pellicciotti, Francesca

    2016-04-01

    Supraglacial cliffs are a surface feature typical of debris-covered glaciers, affecting surface evolution, glacier downwasting and mass balance by providing a direct ice-atmosphere interface. As a result, melt rates can be very high and ice cliffs may account for a significant portion of the total glacier mass loss. However, their contribution to glacier mass balance has rarely been quantified through physically-based models. Most cliff energy balance models are point scale models which calculate energy fluxes at individual cliff locations. Results from the only grid based model to date accurately reflect energy fluxes and cliff melt, but modelled backwasting patterns are in some cases unrealistic, as the distribution of melt rates would lead to progressive shallowing and disappearance of cliffs. Based on a unique multitemporal dataset of cliff topography and backwasting obtained from high-resolution terrestrial and aerial Structure-from-Motion analysis on Lirung Glacier in Nepal, it is apparent that cliffs exhibit a range of behaviours but most do not rapidly disappear. The patterns of evolution cannot be explained satisfactorily by atmospheric melt alone, and are moderated by the presence of supraglacial ponds at the base of cliffs and by cliff reburial with debris. Here, we document the distinct patterns of evolution including disappearance, growth and stability. We then use these observations to improve the grid-based energy balance model, implementing periodic updates of the cliff geometry resulting from modelled melt perpendicular to the ice surface. Based on a slope threshold, pixels can be reburied by debris or become debris-free. The effect of ponds are taken into account through enhanced melt rates in horizontal direction on pixels selected based on an algorithm considering distance to the water surface, slope and lake level. We use the dynamic model to first study the evolution of selected cliffs for which accurate, high resolution DEMs are available

  13. Physics. Teacher's Guide. Investigations in Natural Science.

    ERIC Educational Resources Information Center

    Renner, John W.; And Others

    Investigations in Natural Science is a program in secondary school biology, chemistry, and physics based upon the description of science as a quest for knowledge, not the knowledge itself. This teaching guide is designed for use with the 36 physics investigations found in the student manual. These investigations focus on concepts related to:…

  14. Kinesthetic Investigations in the Physics Classroom

    ERIC Educational Resources Information Center

    Whitworth, Brooke A.; Chiu, Jennifer L.; Bell, Randy L.

    2014-01-01

    Creating investigations that allow students to see physics in their everyday world and to be kinesthetically active outside of the traditional physics classroom can be incredibly engaging and effective. The investigations we developed were inquiry investigations in which students engaged in concrete experiences before we discussed the abstract…

  15. Physics. Teacher's Guide. Investigations in Natural Science.

    ERIC Educational Resources Information Center

    Renner, John W.; And Others

    Investigations in Natural Science is a program in secondary school biology, chemistry, and physics based upon the description of science as a quest for knowledge, not the knowledge itself. This teaching guide is designed for use with the 36 physics investigations found in the student manual. These investigations focus on concepts related to:…

  16. Kinesthetic Investigations in the Physics Classroom

    ERIC Educational Resources Information Center

    Whitworth, Brooke A.; Chiu, Jennifer L.; Bell, Randy L.

    2014-01-01

    Creating investigations that allow students to see physics in their everyday world and to be kinesthetically active outside of the traditional physics classroom can be incredibly engaging and effective. The investigations we developed were inquiry investigations in which students engaged in concrete experiences before we discussed the abstract…

  17. Investigation of Higher Brain Functions in Music Composition Using Models of the Cortex Based on Physical System Analogies.

    NASA Astrophysics Data System (ADS)

    Leng, Xiaodan

    The trion model was developed using the Mountcastle organizational principle for the column as the basic neuronal network in the cortex and the physical system analogy of Fisher's ANNNI spin model. An essential feature is that it is highly structured in time and in spatial connections. Simulations of a network of trions have shown that large numbers of quasi-stable, periodic spatial-temporal firing patterns can be excited. Characteristics of these patterns include the quality of being readily enhanced by only a small change in connection strengths, and that the patterns evolve in certain natural sequences from one to another. With only somewhat different parameters than used for studying memory and pattern recognition, much more flowing and intriguing patterns emerged from the simulations. The results were striking when these probabilistic evolutions were mapped onto pitches and instruments to produce music: For example different simple mappings of the same evolution give music having the "flavor" of a minuet, a waltz, folk music, or styles of specific periods. A theme can be learned so that evolutions have this theme and its variations reoccurring more often. That the trion model is a viable model for the coding of musical structure in human composition and perception is suggested. It is further proposed that model is relevant for examining creativity in the higher cognitive functions of mathematics and chess, which are similar to music. An even higher level of cortical organization was modeled by coupling together several trion networks. Further, one of the crucial features of higher brain function, especially in music composition or appreciation, is the role of emotion and mood as controlled by the many neuromodulators or neuropeptides. The MILA model whose underlying basis is zero-level representation of Kac-Moody algebra is used to modulate periodically the firing threshold of each network. Our preliminary results show that the introduction of "neuromodulation

  18. Physics. Student Investigations and Readings. Investigations in Natural Science.

    ERIC Educational Resources Information Center

    Renner, John W.; And Others

    Investigations in Natural Science is a program in secondary school biology, chemistry, and physics based upon the description of science as a quest for knowledge, not the knowledge itself. This student manual contains the 36 physics investigations which focus on concepts related to: movement; vectors; falling objects; force and acceleration; a…

  19. Physics. Student Investigations and Readings. Investigations in Natural Science.

    ERIC Educational Resources Information Center

    Renner, John W.; And Others

    Investigations in Natural Science is a program in secondary school biology, chemistry, and physics based upon the description of science as a quest for knowledge, not the knowledge itself. This student manual contains the 36 physics investigations which focus on concepts related to: movement; vectors; falling objects; force and acceleration; a…

  20. Numerical investigation of the Taylor-Couette and Batchelor flows with heat transfer: physics and numerical modelling

    NASA Astrophysics Data System (ADS)

    Kiełczewski, K.; Tuliszka-Sznitko, E.; Bontoux, P.

    2014-08-01

    In the paper the authors present the results obtained during a numerical investigation (Direct Numerical Simulation/Spectral Vanishing Viscosity method - DNS/SVV) of a flow with heat transfer in rotating cavities (i.e. the flow between two concentric disks and two concentric cylinders). These model flows are useful from numerical and experimental point of view among others because of the simplicity of their geometry. Simultaneously, the flows in rotating cavities appear in numerous industrial installations and machines in the field of mechanics and chemistry, e.g., in ventilation installations, desalination tanks and waste water tanks, in cooling system, in gas turbines and axial compressors. In the paper attention is focused on the laminar-turbulent region in the configuration of the large aspect ratio i.e. Taylor-Couette flow (a Batchelor flow case of small aspect ratio Γ = 0.04 is also presented for comparison). The main purpose of computations is to investigate the influence of different parameters (the aspect ratio, the end-wall boundary conditions and temperature gradient) on the flow structure and flow characteristics. For the non-isothermal flow cases the Nusselt number distributions along cylinders are presented and are correlated with the flow structures. The λ2 method has been used for visualization.

  1. Investigation on the Influence of Abutment Pressure on the Stability of Rock Bolt Reinforced Roof Strata Through Physical and Numerical Modeling

    NASA Astrophysics Data System (ADS)

    Kang, Hongpu; Li, Jianzhong; Yang, Jinghe; Gao, Fuqiang

    2017-02-01

    In underground coal mining, high abutment loads caused by the extraction of coal can be a major contributor to many rock mechanic issues. In this paper, a large-scale physical modeling of a 2.6 × 2.0 × 1.0 m entry roof has been conducted to investigate the fundamentals of the fracture mechanics of entry roof strata subjected to high abutment loads. Two different types of roof, massive roof and laminated roof, are considered. Rock bolt system has been taken into consideration. A distinct element analyses based on the physical modeling conditions have been performed, and the results are compared with the physical results. The physical and numerical models suggest that under the condition of high abutment loads, the massive roof and the laminated roof fail in a similar pattern which is characterized as vertical tensile fracturing in the middle of the roof and inclined shear fracturing initiated at the roof and rib intersections and propagated deeper into the roof. Both the massive roof and the laminated roof collapse in a shear sliding mode shortly after shear fractures are observed from the roof surface. It is found that shear sliding is a combination of tensile cracking of intact rock and sliding on bedding planes and cross joints. Shear sliding occurs when the abutment load is much less than the compressive strength of roof.

  2. Investigation on the Fluid Flow and Mixing Phenomena in a Ruhrstahl-Heraeus (RH) Steel Degasser Using Physical Modeling

    NASA Astrophysics Data System (ADS)

    Zhang, Lifeng; Li, Fei

    2014-07-01

    In this article, the water model was established to investigate the fluid flow and mixing phenomena during the Ruhrstahl-Heraeus refining process. The mixing time was measured by detecting the conductivity. The velocity, turbulent energy and its dissipation rate were measured using a particle-image velocimetry. There were several findings in the current study. The jet from the downleg penetrated to the bottom of the ladle, collided with the right wall of the ladle, and then went upward and sloped left to enter the upleg, generating a recirculation eddy below the upleg. The turbulent fluctuation velocities at different directions were different so that the k- ɛ turbulent model is invalid to accurately study the fluid flow during ladle refining process. The mixing time was usually three to four times that of the recirculation time, and the mixing was different at different locations. When the mixing time is reported, the location where the mixing time is measured should be clearly mentioned. The mixing time was dependent on the stirring power by t mix ~ ɛ-0.42.

  3. Beyond Standard Model Physics

    SciTech Connect

    Bellantoni, L.

    2009-11-01

    There are many recent results from searches for fundamental new physics using the TeVatron, the SLAC b-factory and HERA. This talk quickly reviewed searches for pair-produced stop, for gauge-mediated SUSY breaking, for Higgs bosons in the MSSM and NMSSM models, for leptoquarks, and v-hadrons. There is a SUSY model which accommodates the recent astrophysical experimental results that suggest that dark matter annihilation is occurring in the center of our galaxy, and a relevant experimental result. Finally, model-independent searches at D0, CDF, and H1 are discussed.

  4. Physical, Chemical, and Immunohistochemical Investigation of the Damage to Salivary Glands in a Model of Intoxication with Aluminium Citrate

    PubMed Central

    da Costa, Natacha M. M.; Correa, Russell S.; Júnior, Ismael S. M.; Figueiredo, Adilson J. R.; Vilhena, Kelly F. B.; Farias-Junior, Paulo M. A.; Teixeira, Francisco B.; Ferreira, Nayana M. M.; Pereira-Júnior, João B.; Dantas, Kelly das Graças F.; da Silva, Marcia C. F.; Silva-Junior, Ademir F.; Alves-Junior, Sergio de M.; Pinheiro, João de Jesus V.; Lima, Rafael Rodrigues

    2014-01-01

    Aluminum absorption leads to deposits in several tissues. In this study, we have investigated, to our knowledge for the first time, aluminum deposition in the salivary glands in addition to the resultant cellular changes in the parotid and submandibular salivary glands in a model of chronic intoxication with aluminum citrate in rats. Aluminum deposits were observed in the parotid and submandibular glands. Immunohistochemical evaluation of cytokeratin-18 revealed a decreased expression in the parotid gland with no changes in the submandibular gland. A decreased expression of α-smooth muscle actin was observed in the myoepithelial cells of both glands. The expression of metallothionein I and II (MT-I/II), a group of metal-binding proteins, which are useful indicators for detecting physiological responses to metal exposure, was higher in both glands. In conclusion, we have shown that at a certain time and quantity of dosage, aluminum citrate promotes aluminum deposition in the parotid and submandibular glands, leads to an increased expression of MT-I/II in both the glands, damages the cytoskeleton of the myoepithelial cells in both glands, and damages the cytoskeleton of the acinar/ductal cells of the parotid glands, with the submandibular glands showing resistance to the toxicity of the latter. PMID:25464135

  5. Physical, chemical, and immunohistochemical investigation of the damage to salivary glands in a model of intoxication with aluminium citrate.

    PubMed

    da Costa, Natacha M M; Correa, Russell S; Júnior, Ismael S M; Figueiredo, Adilson J R; Vilhena, Kelly F B; Farias-Junior, Paulo M A; Teixeira, Francisco B; Ferreira, Nayana M M; Pereira-Júnior, João B; Dantas, Kelly das Graças F; da Silva, Marcia C F; Silva-Junior, Ademir F; Alves-Junior, Sergio de M; Pinheiro, João de Jesus V; Lima, Rafael Rodrigues

    2014-11-28

    Aluminum absorption leads to deposits in several tissues. In this study, we have investigated, to our knowledge for the first time, aluminum deposition in the salivary glands in addition to the resultant cellular changes in the parotid and submandibular salivary glands in a model of chronic intoxication with aluminum citrate in rats. Aluminum deposits were observed in the parotid and submandibular glands. Immunohistochemical evaluation of cytokeratin-18 revealed a decreased expression in the parotid gland with no changes in the submandibular gland. A decreased expression of α-smooth muscle actin was observed in the myoepithelial cells of both glands. The expression of metallothionein I and II (MT-I/II), a group of metal-binding proteins, which are useful indicators for detecting physiological responses to metal exposure, was higher in both glands. In conclusion, we have shown that at a certain time and quantity of dosage, aluminum citrate promotes aluminum deposition in the parotid and submandibular glands, leads to an increased expression of MT-I/II in both the glands, damages the cytoskeleton of the myoepithelial cells in both glands, and damages the cytoskeleton of the acinar/ductal cells of the parotid glands, with the submandibular glands showing resistance to the toxicity of the latter.

  6. Physical and chemical investigations on natural dyes

    NASA Astrophysics Data System (ADS)

    Acquaviva, S.; D'Anna, E.; de Giorgi, M. L.; Della Patria, A.; Baraldi, P.

    2010-09-01

    Natural dyes have been used extensively in the past for many purposes, such us to colour fibers and to produce inks, watercolours and paints, but their use declined rapidly after the discovery of synthetic colours. Nowadays we witness a renewed interest, as natural dyes are neither toxic nor polluting. In this work, physical and chemical properties of four selected dyes, namely red (Madder), yellow (Weld and Turmeric) and blue (Woad) colours, produced by means of traditional techniques at the Museo dei Colori Naturali (Lamoli, Italy), have been investigated. The chromatic properties have been studied through the reflectance spectroscopy, a non-invasive technique for the characterisation of chromaticity. Reflection spectra both from powders and egg-yolk tempera models have been acquired to provide the typical features of the dyes in the UV-vis spectral range. Moreover, to assess the feasibility of laser cleaning procedures, tempera layers were investigated after irradiation with an excimer laser. Micro Raman spectroscopy, Scanning Electron Microscopy and Energy Dispersive X-Ray analyses have complemented the survey, returning compositional and morphological information as well. Efforts have been made to give scientific feedback to the production processes and to support the research activity in the restoration of the artworks where these dyes were employed.

  7. Blooms of the Toxic Dinoflagellate Alexandrium fundyense in the Gulf of Maine: Investigations Using a Physical-Biological Model

    DTIC Science & Technology

    2005-02-01

    B. A., Bronzino , A. C., Matrai, P., Thompson, B., Keller, M., McGillicuddy, D. J., Hyatt, J., submitted. Experimental and modeling observations of...and Oceanography (submitted). Anderson, D. M., Stock, C. A., Keafer, B. A., Bronzino , A. C., Matrai, P., Thompson, B., Keller, M., McGillicuddy, D. J...submitted). Anderson, D. M., Stock, C. A., Keafer, B. A., Bronzino , A. C., Matrai, P., Thompson, B., Keller, M., McGillicuddy, D. J., Hyatt, J

  8. Physical models of cognition

    NASA Astrophysics Data System (ADS)

    Zak, Michail

    1994-05-01

    This paper presents and discusses physical models for simulating some aspects of neural intelligence, and, in particular, the process of cognition. The main departure from the classical approach here is in utilization of a terminal version of classical dynamics introduced by the author earlier. Based upon violations of the Lipschitz condition at equilibrium points, terminal dynamics attains two new fundamental properties: it is spontaneous and nondeterministic. Special attention is focused on terminal neurodynamics as a particular architecture of terminal dynamics which is suitable for modeling of information flows. Terminal neurodynamics possesses a well-organized probabilistic structure which can be analytically predicted, prescribed, and controlled, and therefore which presents a powerful tool for modeling real-life uncertainties. Two basic phenomena associated with random behavior of neurodynamic solutions are exploited. The first one is a stochastic attractor—a stable stationary stochastic process to which random solutions of a closed system converge. As a model of the cognition process, a stochastic attractor can be viewed as a universal tool for generalization and formation of classes of patterns. The concept of stochastic attractor is applied to model a collective brain paradigm explaining coordination between simple units of intelligence which perform a collective task without direct exchange of information. The second fundamental phenomenon discussed is terminal chaos which occurs in open systems. Applications of terminal chaos to information fusion as well as to explanation and modeling of coordination among neurons in biological systems are discussed. It should be emphasized that all the models of terminal neurodynamics are implementable in analog devices, which means that all the cognition processes discussed in the paper are reducible to the laws of Newtonian mechanics.

  9. Physical Models of Cognition

    NASA Technical Reports Server (NTRS)

    Zak, Michail

    1994-01-01

    This paper presents and discusses physical models for simulating some aspects of neural intelligence, and, in particular, the process of cognition. The main departure from the classical approach here is in utilization of a terminal version of classical dynamics introduced by the author earlier. Based upon violations of the Lipschitz condition at equilibrium points, terminal dynamics attains two new fundamental properties: it is spontaneous and nondeterministic. Special attention is focused on terminal neurodynamics as a particular architecture of terminal dynamics which is suitable for modeling of information flows. Terminal neurodynamics possesses a well-organized probabilistic structure which can be analytically predicted, prescribed, and controlled, and therefore which presents a powerful tool for modeling real-life uncertainties. Two basic phenomena associated with random behavior of neurodynamic solutions are exploited. The first one is a stochastic attractor ; a stable stationary stochastic process to which random solutions of a closed system converge. As a model of the cognition process, a stochastic attractor can be viewed as a universal tool for generalization and formation of classes of patterns. The concept of stochastic attractor is applied to model a collective brain paradigm explaining coordination between simple units of intelligence which perform a collective task without direct exchange of information. The second fundamental phenomenon discussed is terminal chaos which occurs in open systems. Applications of terminal chaos to information fusion as well as to explanation and modeling of coordination among neurons in biological systems are discussed. It should be emphasized that all the models of terminal neurodynamics are implementable in analog devices, which means that all the cognition processes discussed in the paper are reducible to the laws of Newtonian mechanics.

  10. Physical Models of Cognition

    NASA Technical Reports Server (NTRS)

    Zak, Michail

    1994-01-01

    This paper presents and discusses physical models for simulating some aspects of neural intelligence, and, in particular, the process of cognition. The main departure from the classical approach here is in utilization of a terminal version of classical dynamics introduced by the author earlier. Based upon violations of the Lipschitz condition at equilibrium points, terminal dynamics attains two new fundamental properties: it is spontaneous and nondeterministic. Special attention is focused on terminal neurodynamics as a particular architecture of terminal dynamics which is suitable for modeling of information flows. Terminal neurodynamics possesses a well-organized probabilistic structure which can be analytically predicted, prescribed, and controlled, and therefore which presents a powerful tool for modeling real-life uncertainties. Two basic phenomena associated with random behavior of neurodynamic solutions are exploited. The first one is a stochastic attractor ; a stable stationary stochastic process to which random solutions of a closed system converge. As a model of the cognition process, a stochastic attractor can be viewed as a universal tool for generalization and formation of classes of patterns. The concept of stochastic attractor is applied to model a collective brain paradigm explaining coordination between simple units of intelligence which perform a collective task without direct exchange of information. The second fundamental phenomenon discussed is terminal chaos which occurs in open systems. Applications of terminal chaos to information fusion as well as to explanation and modeling of coordination among neurons in biological systems are discussed. It should be emphasized that all the models of terminal neurodynamics are implementable in analog devices, which means that all the cognition processes discussed in the paper are reducible to the laws of Newtonian mechanics.

  11. Investigations and modeling of physical processes in high-density information recording with the help of inorganic resists

    NASA Astrophysics Data System (ADS)

    Kostyukevych, Sergey A.; Shepeljavi, Peter E.; Stronski, Alexander V.; Indutnyi, Ivan Z.

    1995-11-01

    The applications of chalcogenide glasses (CG) and the structures on their base in the technology of optical disks are reviewed. In brief are described the properties of high- resolution inorganic thin film structures CG-Ag and CG layers. The properties of such resists and peculiarities of laser lithography under the influence of sharp-focused laser irradiation with the objective of formation of master disks and the tracking guides of optical disks were investigated. It is shown that under laser exposure the local heating of the resist and also the photostructural transformations, activated by this heating, provide the narrowing of the lines of the resistive mask in comparison to the size of the exposure light spot. Using the As2S3 layers the minimal width of lines 0.17 micrometer was obtained, under the exposure wavelength 476 nm and laser spot halfwidth 1 micrometer. This enables us to decrease the period of the tracking guides with the purpose of increasing the density of information recording. The possibility is shown of the formation of the tracking guides structure with the period up to the 0.8 micrometer.

  12. MODELING PHYSICAL HABITAT PARAMETERS

    EPA Science Inventory

    Salmonid populations can be affected by alterations in stream physical habitat. Fish productivity is determined by the stream's physical habitat structure ( channel form, substrate distribution, riparian vegetation), water quality, flow regime and inputs from the watershed (sedim...

  13. MODELING PHYSICAL HABITAT PARAMETERS

    EPA Science Inventory

    Salmonid populations can be affected by alterations in stream physical habitat. Fish productivity is determined by the stream's physical habitat structure ( channel form, substrate distribution, riparian vegetation), water quality, flow regime and inputs from the watershed (sedim...

  14. Evolutionary Industrial Physical Model Generation

    NASA Astrophysics Data System (ADS)

    Carrascal, Alberto; Alberdi, Amaia

    Both complexity and lack of knowledge associated to physical processes makes physical models design an arduous task. Frequently, the only available information about the physical processes are the heuristic data obtained from experiments or at best a rough idea on what are the physical principles and laws that underlie considered physical processes. Then the problem is converted to find a mathematical expression which fits data. There exist traditional approaches to tackle the inductive model search process from data, such as regression, interpolation, finite element method, etc. Nevertheless, these methods either are only able to solve a reduced number of simple model typologies, or the given black-box solution does not contribute to clarify the analyzed physical process. In this paper a hybrid evolutionary approach to search complex physical models is proposed. Tests carried out on a real-world industrial physical process (abrasive water jet machining) demonstrate the validity of this approach.

  15. Building Mental Models by Dissecting Physical Models

    ERIC Educational Resources Information Center

    Srivastava, Anveshna

    2016-01-01

    When students build physical models from prefabricated components to learn about model systems, there is an implicit trade-off between the physical degrees of freedom in building the model and the intensity of instructor supervision needed. Models that are too flexible, permitting multiple possible constructions require greater supervision to…

  16. Building Mental Models by Dissecting Physical Models

    ERIC Educational Resources Information Center

    Srivastava, Anveshna

    2016-01-01

    When students build physical models from prefabricated components to learn about model systems, there is an implicit trade-off between the physical degrees of freedom in building the model and the intensity of instructor supervision needed. Models that are too flexible, permitting multiple possible constructions require greater supervision to…

  17. Investigating Microvibration Sources Modelling

    NASA Astrophysics Data System (ADS)

    Addari, Daniele; Aglietti, Guglielmo S.; Remedia, Marcello

    2014-06-01

    One of the challenges related to microvibration is investigating the characterisation of the microvibration sources (here emphasis is given to reaction wheel assemblies) on board satellites. This usually involves series of experiments to characterise the hardware and produce representative models. Here we present a methodology that gives good estimates covering a wide frequency range and reduce the complexity of the test campaign.In addition, a practical example of coupling between a reaction wheel assembly and a structural panel where the coupled loads have been estimated using the mathematical model and compared with experimental test results (retrieved using an interface load transducer) will be presented, giving indications of the level of accuracy that can be expected from this type of analyses.

  18. Streamflow generation in humid West Africa: the role of Bas-fonds investigated with a physically based model of the Critical Zone

    NASA Astrophysics Data System (ADS)

    Hector, B.; Cohard, J. M.; Séguis, L.

    2015-12-01

    In West Africa, the drought initiated in the 70's-80's together with intense land-use change due to increasing food demand produced very contrasted responses on water budgets of the critical zone (CZ) depending on the lithological and pedological contexts. In Sahel, streamflow increased, mostly due to increasing hortonian runoff from soil crusting, and so did groundwater storage. On the contrary, in the more humid southern Sudanian area, streamflow decreased and no clear signal has been observed concerning water storage in this hard-rock basement area. There, Bas-fonds are fundamental landscape features. They are seasonally water-logged valley bottoms from which first order streams originate, mostly composed of baseflow. They are a key feature for understanding streamflow generation processes. They also carry an important agronomic potential due to their moisture and nutrient availability. The role of Bas-fond in streamflow generation processes is investigated using a physically-based coupled model of the CZ, ParFlow-CLM at catchment scale (10km²). The model is evaluated against classical hydrological measurements (water table, soil moisture, streamflow, fluxes), acquired in the AMMA-CATCH observing system for the West African monsoon, but also hybrid gravity data which measure integrated water storage changes. The bas-fond system is shown to be composed of two components with different time scales. The slow component is characterized by the seasonal and interannual amplitude of the permanent water table, which is disconnected from streams, fed by direct recharge and lowered by evapotranspiration, mostly from riparian areas. The fast component is characterized by thresholds in storage and perched and permanent water tables surrounding the bas-fond during the wet season, which are linked with baseflow generation. This is a first step toward integrating these features into larger scale modeling of the critical zone for evaluating the effect of precipitation

  19. Improvement of Learning Process and Learning Outcomes in Physics Learning by Using Collaborative Learning Model of Group Investigation at High School (Grade X, SMAN 14 Jakarta)

    ERIC Educational Resources Information Center

    Astra, I. Made; Wahyuni, Citra; Nasbey, Hadi

    2015-01-01

    The aim of this research is to improve the quality of physics learning through application of collaborative learning of group investigation at grade X MIPA 2 SMAN 14 Jakarta. The method used in this research is classroom action research. This research consisted of three cycles was conducted from April to May in 2014. Each cycle consists of…

  20. Diagnostic set-up and modelling for investigation of synergy between 3D edge physics and plasma-wall interactions on Wendelstein 7-X

    NASA Astrophysics Data System (ADS)

    Liang, Y.; Neubauer, O.; König, R.; Krychowiak, M.; Schweer, B.; Denner, P.; Rack, M.; Reiter, D.; Feng, Y.; Krämer-Flecken, A.; Drews, P.; Hasenbeck, F.; Liu, S.; Gao, Y.; Wang, E. H.; Wei, Y.; Dostal, M.; Li, L.; Wang, N.; Geiger, J.; Suzuki, Y.; Sereda, S.; Börner, P.; Weger, A. C.; Biel, W.; Brezinsek, S.; Charl, A.; Czymek, G.; Höschen, D.; Effenberg, F.; Grulke, O.; Nicolai, D.; Lambertz, H. T.; Marchuk, O.; Schmitz, O.; Hollfeld, K. P.; Knaup, M.; Offermanns, G.; Satheeswaran, G.; Terra, A.; Thomas, J.; Pederson, T. S.; Samm, U.; Linsmeier, C.; the W7-X Team

    2017-06-01

    A group of edge diagnostics and modelling has been developed for investigation of synergy between 3D edge physics and plasma-wall interactions on Wendelstein 7-X (W7-X). Two endoscopes have been designed for visible and ultraviolet spectroscopy and tomography of the plasma edge, along with infrared thermography of the divertor tiles. 2D profiles of impurities (e.g. helium, carbon) will be measured by two endoscopes viewing the island divertor region in the plasma edge with a spatial resolution of  <2 mm. A multipurpose manipulator, which is used as the carrier either of the probe head for measuring the plasma edge profiles or of samples for plasma exposure studies, was installed at the outside mid-plane on W7-X in 2015. A poloidal correlation reflectometer has also been installed at W7-X. The system consists of an antenna array observing the propagation of turbulent phenomena in the mid-plane. The EMC3-EIRENE code package has been adapted for plasma edge transport in helium plasma at W7-X using a hybrid fluid-kinetic approach by enabling EMC3 to treat non-hydrogen isotopes and extending the usage of EIRENE features within EMC3-EIRENE.

  1. An investigation of the effect of instruction in physics on the formation of mental models for problem-solving in the context of simple electric circuits

    NASA Astrophysics Data System (ADS)

    Beh, Kian Lim

    2000-10-01

    This study was designed to explore the effect of a typical traditional method of instruction in physics on the formation of useful mental models among college students for problem-solving using simple electric circuits as a context. The study was also aimed at providing a comprehensive description of the understanding regarding electric circuits among novices and experts. In order to achieve these objectives, the following two research approaches were employed: (1) A students survey to collect data from 268 physics students; and (2) An interview protocol to collect data from 23 physics students and 24 experts (including 10 electrical engineering graduates, 4 practicing electrical engineers, 2 secondary school physics teachers, 8 physics lecturers, and 4 electrical engineers). Among the major findings are: (1) Most students do not possess accurate models of simple electric circuits as presented implicitly in physics textbooks; (2) Most students display good procedural understanding for solving simple problems concerning electric circuits but have no in-depth conceptual understanding in terms of practical knowledge of current, voltage, resistance, and circuit connections; (3) Most students encounter difficulty in discerning parallel connections that are drawn in a non-conventional format; (4) After a year of college physics, students show significant improvement in areas, including practical knowledge of current and voltage, ability to compute effective resistance and capacitance, ability to identify circuit connections, and ability to solve problems; however, no significance was found in practical knowledge of resistance and ability to connect circuits; and (5) The differences and similarities between the physics students and the experts include: (a) Novices perceive parallel circuits more in terms of 'branch', 'current', and 'resistors with the same resistance' while experts perceive parallel circuits more in terms of 'node', 'voltage', and 'less resistance'; and

  2. Modeling QCD for Hadron Physics

    SciTech Connect

    Tandy, P. C.

    2011-10-24

    We review the approach to modeling soft hadron physics observables based on the Dyson-Schwinger equations of QCD. The focus is on light quark mesons and in particular the pseudoscalar and vector ground states, their decays and electromagnetic couplings. We detail the wide variety of observables that can be correlated by a ladder-rainbow kernel with one infrared parameter fixed to the chiral quark condensate. A recently proposed novel perspective in which the quark condensate is contained within hadrons and not the vacuum is mentioned. The valence quark parton distributions, in the pion and kaon, as measured in the Drell Yan process, are investigated with the same ladder-rainbow truncation of the Dyson-Schwinger and Bethe-Salpeter equations.

  3. Modeling Physical Objects

    DTIC Science & Technology

    1990-10-01

    of the conference will be published by Oxford University Press . At the ASME Conference on Design Automation in Chicago. D. Dmtta and I presented... University Press , 1991. .1. Jung-Hong (’huang, "Surface Approximations in Geometric Modeling," PhD Diss., Dept. of ComIp. Sci., Purdue University: Rept. CER-90-37. September 1990. 3 ...utoination. Chicago, 1990: (with D. Dutta). 3. "How to Construct the Skeleton of CSG Objects," Proc. ,Ith JA1A Con!. Math. of Suifaces. Oxford

  4. Physical model of kitesurfing

    NASA Astrophysics Data System (ADS)

    Zimoch, Pawel; Paxson, Adam; Obropta, Edward; Peleg, Tom; Parker, Sam; Hosoi, A. E.

    2013-11-01

    Kitesurfing is a popular water sport, similar to windsurfing, utilizing a surfboard-like platform pulled by a large kite operated by the surfer. While the kite generates thrust that propels the surfer across the water, much like a traditional sail, it is also capable of generating vertical forces on the surfer, reducing the hydrodynamic lift generated by the surfboard required to support the surfer's weight. This in turn reduces drag acting on the surfboard, making sailing possible in winds lower than required by other sailing sports. We describe aerodynamic and hydrodynamic models for the forces acting on the kite and the surfboard, and couple them while considering the kite's position in space and the requirement for the kite to support its own weight. We then use these models to quantitatively characterize the significance of the vertical force component generated by the kite on sailing performance (the magnitude of achievable steady-state velocities and the range of headings, relative to the true wind direction, in which sailing is possible), and the degradation in sailing performance with decreasing wind speeds. Finally, we identify the areas of kite and surfboard design whose development could have the greatest impact on improving sailing performance in low wind conditions.

  5. Physical Modeling of Microtubules Network

    NASA Astrophysics Data System (ADS)

    Allain, Pierre; Kervrann, Charles

    2014-10-01

    Microtubules (MT) are highly dynamic tubulin polymers that are involved in many cellular processes such as mitosis, intracellular cell organization and vesicular transport. Nevertheless, the modeling of cytoskeleton and MT dynamics based on physical properties is difficult to achieve. Using the Euler-Bernoulli beam theory, we propose to model the rigidity of microtubules on a physical basis using forces, mass and acceleration. In addition, we link microtubules growth and shrinkage to the presence of molecules (e.g. GTP-tubulin) in the cytosol. The overall model enables linking cytosol to microtubules dynamics in a constant state space thus allowing usage of data assimilation techniques.

  6. Pre-Service Physics Teachers' Argumentation in a Model Rocketry Physics Experience

    ERIC Educational Resources Information Center

    Gürel, Cem; Süzük, Erol

    2017-01-01

    This study investigates the quality of argumentation developed by a group of pre-service physics teachers' (PSPT) as an indicator of subject matter knowledge on model rocketry physics. The structure of arguments and scientific credibility model was used as a design framework in the study. The inquiry of model rocketry physics was employed in…

  7. Investigation of the behavior of VOCs in ground water across fine- and coarse-grained geological contacts using a medium-scale physical model

    SciTech Connect

    Hoffman, F.; Chiarappa, M.L.

    1998-03-01

    One of the serious impediments to the remediation of ground water contaminated with volatile organic compounds (VOCs) is that the VOCs are retarded with respect to the movement of the ground water. Although the processes that result in VOC retardation are poorly understood, we have developed a conceptual model that includes several retarding mechanisms. These include adsorption to inorganic surfaces, absorption to organic carbon, and diffusion into areas of immobile waters. This project was designed to evaluate the relative contributions of these mechanisms; by improving our understanding, we hope to inspire new remediation technologies or approaches. Our project consisted of a series of column experiments designed to measure the retardation, in different geological media, of four common ground water VOCs (chloroform, carbon tetrachloride, trichloroethylene, and tetrachloroethylene) which have differing physical and chemical characteristics. It also included a series of diffusion parameters that constrain the model, we compared the data from these experiments to the output of a computational model.

  8. GRIPs (Group Investigation Problems) for Introductory Physics

    NASA Astrophysics Data System (ADS)

    Moore, Thomas A.

    2006-12-01

    GRIPs lie somewhere between homework problems and simple labs: they are open-ended questions that require a mixture of problem-solving skills and hands-on experimentation to solve practical puzzles involving simple physical objects. In this talk, I will describe three GRIPs that I developed for a first-semester introductory calculus-based physics course based on the "Six Ideas That Shaped Physics" text. I will discuss the design of the three GRIPs we used this past fall, our experience in working with students on these problems, and students' response as reported on course evaluations.

  9. Using a physically-based model, tRIBS-Erosion, for investigating the effects of climate change in semi-arid headwater basins.

    NASA Astrophysics Data System (ADS)

    Francipane, Antonio; Fatichi, Simone; Ivanov, Valeriy Y.; Noto, Leonardo V.

    2013-04-01

    Soil erosion due to rainfall detachment and flow entrainment of soil particles is a physical process responsible for a continuous evolution of landscapes. The rate and spatial distribution of this phenomenon depend on several factors such as climate, hydrologic regime, geomorphic characteristics, and vegetation of a basin. Many studies have demonstrated that climate-erosion linkage in particular influences basin sediment yield and landscape morphology. Although soil erosion rates are expected to change in response to climate, these changes can be highly non-linear and thus require mechanistic understanding of underlying causes. In this study, an integrated geomorphic component of the physically-based, spatially distributed hydrological model, tRIBS, the TIN-based Real-time Integrated Basin Simulator, is used to analyze the sensitivity of semi-arid headwater basins to climate change. Downscaled outputs of global circulation models are used to inform a stochastic weather generator that produces an ensemble of climate scenarios for an area in the Southwest U.S. The ensemble is used as input to the integrated model that is applied to different headwater basins of the Walnut Gulch Experimental Watershed to understand basin response to climate change in terms of runoff and sediment yield. Through a model application to multiple catchments, a scaling relationship between specific sediment yield and drainage basin area is also addressed and probabilistic inferences on future changes in catchment runoff and yield are drawn. Geomorphological differences among catchments do not influence specific changes in runoff and sediment transport that are mostly determined by precipitation changes. Despite a large uncertainty dictated by climate change projections and stochastic variability, sediment transport is predicted to decrease despite a non-negligible possibility of larger runoff rates.

  10. Standard Model of Particle Physics--a health physics perspective.

    PubMed

    Bevelacqua, J J

    2010-11-01

    The Standard Model of Particle Physics is reviewed with an emphasis on its relationship to the physics supporting the health physics profession. Concepts important to health physics are emphasized and specific applications are presented. The capability of the Standard Model to provide health physics relevant information is illustrated with application of conservation laws to neutron and muon decay and in the calculation of the neutron mean lifetime.

  11. Building mental models by dissecting physical models.

    PubMed

    Srivastava, Anveshna

    2016-01-01

    When students build physical models from prefabricated components to learn about model systems, there is an implicit trade-off between the physical degrees of freedom in building the model and the intensity of instructor supervision needed. Models that are too flexible, permitting multiple possible constructions require greater supervision to ensure focused learning; models that are too constrained require less supervision, but can be constructed mechanically, with little to no conceptual engagement. We propose "model-dissection" as an alternative to "model-building," whereby instructors could make efficient use of supervisory resources, while simultaneously promoting focused learning. We report empirical results from a study conducted with biology undergraduate students, where we demonstrate that asking them to "dissect" out specific conceptual structures from an already built 3D physical model leads to a significant improvement in performance than asking them to build the 3D model from simpler components. Using questionnaires to measure understanding both before and after model-based interventions for two cohorts of students, we find that both the "builders" and the "dissectors" improve in the post-test, but it is the latter group who show statistically significant improvement. These results, in addition to the intrinsic time-efficiency of "model dissection," suggest that it could be a valuable pedagogical tool. © 2015 The International Union of Biochemistry and Molecular Biology.

  12. Detector Modeling in Astroparticle Physics

    NASA Astrophysics Data System (ADS)

    Petrera, Sergio

    2007-12-01

    Detector modeling is an important step for the interpretation of experimental data in astroparticle physics. In this paper the most specific features of such process are shown, making use of two remarkable examples: the atmospheric neutrinos in MACRO and the Ultra High Energy cosmic rays in the Pierre Auger experiment.

  13. Accelerator physics and modeling: Proceedings

    SciTech Connect

    Parsa, Z.

    1991-01-01

    This report contains papers on the following topics: Physics of high brightness beams; radio frequency beam conditioner for fast-wave free-electron generators of coherent radiation; wake-field and space-charge effects on high brightness beams. Calculations and measured results for BNL-ATF; non-linear orbit theory and accelerator design; general problems of modeling for accelerators; development and application of dispersive soft ferrite models for time-domain simulation; and bunch lengthening in the SLC damping rings.

  14. Accelerator physics and modeling: Proceedings

    SciTech Connect

    Parsa, Z.

    1991-12-31

    This report contains papers on the following topics: Physics of high brightness beams; radio frequency beam conditioner for fast-wave free-electron generators of coherent radiation; wake-field and space-charge effects on high brightness beams. Calculations and measured results for BNL-ATF; non-linear orbit theory and accelerator design; general problems of modeling for accelerators; development and application of dispersive soft ferrite models for time-domain simulation; and bunch lengthening in the SLC damping rings.

  15. A physical model for dementia

    NASA Astrophysics Data System (ADS)

    Sotolongo-Costa, O.; Gaggero-Sager, L. M.; Becker, J. T.; Maestu, F.; Sotolongo-Grau, O.

    2017-04-01

    Aging associated brain decline often result in some kind of dementia. Even when this is a complex brain disorder a physical model can be used in order to describe its general behavior. A probabilistic model for the development of dementia is obtained and fitted to some experimental data obtained from the Alzheimer's Disease Neuroimaging Initiative. It is explained how dementia appears as a consequence of aging and why it is irreversible.

  16. A physical model for dementia.

    PubMed

    Sotolongo-Costa, O; Gaggero-Sager, L M; Becker, J T; Maestu, F; Sotolongo-Grau, O

    2017-04-15

    Aging associated brain decline often result in some kind of dementia. Even when this is a complex brain disorder a physical model can be used in order to describe its general behavior. A probabilistic model for the development of dementia is obtained and fitted to some experimental data obtained from the Alzheimer's Disease Neuroimaging Initiative. It is explained how dementia appears as a consequence of aging and why it is irreversible.

  17. Physical and mathematical cochlear models

    NASA Astrophysics Data System (ADS)

    Lim, Kian-Meng

    2000-10-01

    The cochlea is an intricate organ in the inner ear responsible for our hearing. Besides acting as a transducer to convert mechanical sound vibrations to electrical neural signals, the cochlea also amplifies and separates the sound signal into its spectral components for further processing in the brain. It operates over a broad-band of frequency and a huge dynamic range of input while maintaining a low power consumption. The present research takes the approach of building cochlear models to study and understand the underlying mechanics involved in the functioning of the cochlea. Both physical and mathematical models of the cochlea are constructed. The physical model is a first attempt to build a life- sized replica of the human cochlea using advanced micro- machining techniques. The model takes a modular design, with a removable silicon-wafer based partition membrane encapsulated in a plastic fluid chamber. Preliminary measurements in the model are obtained and they compare roughly with simulation results. Parametric studies on the design parameters of the model leads to an improved design of the model. The studies also revealed that the width and orthotropy of the basilar membrane in the cochlea have significant effects on the sharply tuned responses observed in the biological cochlea. The mathematical model is a physiologically based model that includes three-dimensional viscous fluid flow and a tapered partition with variable properties along its length. A hybrid asymptotic and numerical method provides a uniformly valid and efficient solution to the short and long wave regions in the model. Both linear and non- linear activity are included in the model to simulate the active cochlea. The mathematical model has successfully reproduced many features of the response in the biological cochlea, as observed in experiment measurements performed on animals. These features include sharply tuned frequency responses, significant amplification with inclusion of activity

  18. Investigating correlation between legal and physical property: possibilities and constraints

    NASA Astrophysics Data System (ADS)

    Dimopoulou, E.; Kitsakis, D.; Tsiliakou, E.

    2015-06-01

    Contemporary urban environment is characterized by complexity and mixed use of space, in which overlapping land parcels and different RRRs (Rights, Restrictions and Responsibilities) are frequent phenomena. Internationally, real property legislation either focuses on surface property or has introduced individual 3D real property units. The former approach merely accommodates issues related to subdivision, expropriation and transactions on part of the real property above or below surface, while the latter provides for defining and registering 3D real property units. National laws require two-dimensional real property descriptions and only a limited number of jurisdictions provide for threedimensional data presentation and recording. International awareness on 3D Cadastre may be apparent through the proposals for transition of existing cadastral systems to 3D along with legal amendments improving national 3D Cadastre legislation. Concurrently the use of appropriate data sources and the correct depiction of 3D property units' boundaries and spatial relationships need to be addressed. Spatial relations and constraints amongst real world objects could be modeled geometrically and topologically utilizing numerous modeling tools, e.g. CityGML, BIM and further sophisticated 3D software or by adapting international standards, e.g. LADM. A direct correlation between legal and physical property should be based on consistent geometry between physical and legal space, improving the accuracy that legal spaces' volumes or locations are defined. To address these issues, this paper investigates correlation possibilities and constraints between legal and physical space of typical 3D property cases. These cases comprise buildings or their interior spaces with mixed use, as well as complex structures described by explicit facade patterns, generated by procedural or by BIM ready 3D models. The 3D models presented are evaluated, regarding compliancy to physical or legal reality.

  19. The Role of Various Curriculum Models on Physical Activity Levels

    ERIC Educational Resources Information Center

    Culpepper, Dean O.; Tarr, Susan J.; Killion, Lorraine E.

    2011-01-01

    Researchers have suggested that physical education curricula can be highly effective in increasing physical activity levels at school (Sallis & Owen, 1999). The purpose of this study was to investigate the impact of various curriculum models on physical activity. Total steps were measured on 1,111 subjects and three curriculum models were studied…

  20. The Role of Various Curriculum Models on Physical Activity Levels

    ERIC Educational Resources Information Center

    Culpepper, Dean O.; Tarr, Susan J.; Killion, Lorraine E.

    2011-01-01

    Researchers have suggested that physical education curricula can be highly effective in increasing physical activity levels at school (Sallis & Owen, 1999). The purpose of this study was to investigate the impact of various curriculum models on physical activity. Total steps were measured on 1,111 subjects and three curriculum models were studied…

  1. Combined Experimental and Numerical Investigations into Laser Propulsion Engineering Physics

    NASA Astrophysics Data System (ADS)

    Kenoyer, David Adam

    The RPI pulsed Laser Propulsion (LP) research effort focuses on the future application of launching nano- and micro-satellites (1-10 kg payloads) into Low Earth Orbit (LEO), using a remote Ground Based Laser (GBL) power station to supply the required energy for flight. This research program includes both experimental and numerical studies investigating the propulsive performance of several engine geometries (constituting a lightcraft family). Using the Lumonics twin K-922m TEA pulsed laser system, axial and lateral thrust, C m, Isp, and η measurements were made for these engine geometries, examining the effects of several critical factors including: engine orientation (e.g. lateral and angular offset), laser pulse energy, pulse repetition frequency, pulse duration, propellant type, and engine size-scaling effects. Investigation into the origins of lateral "beam riding" forces was of particular interest. Lateral impulse measurements and high speed Schlieren photography were utilized to provide an understanding of laser beam-riding/propulsive physics. The acquired lightcraft database was used to further develop an existing 7-Degree Of Freedom (DOF) flight dynamics model extensively calibrated against 16 actual trajectories of small scale model lightcraft flown at White Sands Missile Range, NM on a 10 kW pulsed CO2 laser called PLVTS. The full system 7-DOF model is comprised of updated individual aerodynamics, engine, laser beam propagation, variable vehicle inertia, reaction controls system, and dynamics models, integrated to represent all major phenomena in a consistent framework. This flight dynamics model and associated 7-DOF code provide a physics-based predictive tool for basic research investigations into laser launched lightcraft for suborbital and orbital missions. Simulations were performed to demonstrate the flight capabilities of each engine geometry using the updated lightcraft propulsion database, the results of which further demonstrate that autonomous

  2. Modeling Cyber Physical War Gaming

    DTIC Science & Technology

    2017-08-07

    model-based analysis with experiences of an actual tabletop war game, and offer recommendations on using game-theoretic analysis for enhancing accuracy...execution of the scenario; let the Red cell attack, Blue cell defend, and White cell declare the status as it evolves; and inject additional events to...Description Cost ($) No action (j=0) Basic security (j=1) IDS+ (j=2) IDS enhanced (j=3) IDS+ and physical security (j=4) 1 Upgrade WiFi

  3. Patient specific physical anatomy models.

    PubMed

    Cameron, B M; Holmes, D R; Rettmann, M E; Robb, R A

    2008-01-01

    The advent of small footprint stereo-lithographic printers and the ready availability of segmentation and surface modeling software provide a unique opportunity to create patient-specific physical models of anatomy, validation of image guided intervention applications against phantoms that exhibit naturally occurring anatomic variation. Because these models can incorporate all structures relevant to a procedure, this allows validation to occur under realistic conditions using the same or similar techniques as would be used in a clinical application. This in turn reduces the number of trials and time spent performing in-vivo validation experiments. In this paper, we describe our general approach for the creation of both non-tissue and tissue-mimicking patient-specific models as part of a general-purpose patient emulation system used to validate image guided intervention applications.

  4. A cloud physics investigation utilizing Skylab data

    NASA Technical Reports Server (NTRS)

    Alishouse, J.; Jacobowitz, H.; Wark, D. (Principal Investigator)

    1975-01-01

    The author has identified the following significant results. A number of new scattering calculations for various models were performed. An atmospheric transmittance program to calculate transmittances on a line-by-line basis was developed for the oxygen A band. A copy of the LOWTRAN 2 program was obtained and modified slightly. Thermodynamic results were obtained from snow, cirrus, and coastal stratus to indicate that 1(1.6)/1(2.125) ratio is probably not a reliable indicator of snow, ice particles, or water droplets.

  5. A gender study investigating physics self-efficacy

    NASA Astrophysics Data System (ADS)

    Sawtelle, Vashti

    The underrepresentation of women in physics has been well documented and a source of concern for both policy makers and educators. My dissertation focuses on understanding the role self-efficacy plays in retaining students, particularly women, in introductory physics. I use an explanatory mixed methods approach to first investigate quantitatively the influence of self-efficacy in predicting success and then to qualitatively explore the development of self-efficacy. In the initial quantitative studies, I explore the utility of self-efficacy in predicting the success of introductory physics students, both women and men. Results indicate that self-efficacy is a significant predictor of success for all students. I then disaggregate the data to examine how self-efficacy develops differently for women and men in the introductory physics course. Results show women rely on different sources of self-efficacy than do men, and that a particular instructional environment, Modeling Instruction, has a positive impact on these sources of self-efficacy. In the qualitative phase of the project, this dissertation focuses on the development of self-efficacy. Using the qualitative tool of microanalysis, I introduce a methodology for understanding how self-efficacy develops moment-by-moment using the lens of self-efficacy opportunities. I then use the characterizations of self-efficacy opportunities to focus on a particular course environment and to identify and describe a mechanism by which Modeling Instruction impacts student self-efficacy. Results indicate that the emphasizing the development and deployment of models affords opportunities to impact self-efficacy. The findings of this dissertation indicate that introducing key elements into the classroom, such as cooperative group work, model development and deployment, and interaction with the instructor, create a mechanism by which instructors can impact the self-efficacy of their students. Results from this study indicate that

  6. Simulated, Emulated, and Physical Investigative Analysis (SEPIA) of networked systems.

    SciTech Connect

    Burton, David P.; Van Leeuwen, Brian P.; McDonald, Michael James; Onunkwo, Uzoma A.; Tarman, Thomas David; Urias, Vincent E.

    2009-09-01

    This report describes recent progress made in developing and utilizing hybrid Simulated, Emulated, and Physical Investigative Analysis (SEPIA) environments. Many organizations require advanced tools to analyze their information system's security, reliability, and resilience against cyber attack. Today's security analysis utilize real systems such as computers, network routers and other network equipment, computer emulations (e.g., virtual machines) and simulation models separately to analyze interplay between threats and safeguards. In contrast, this work developed new methods to combine these three approaches to provide integrated hybrid SEPIA environments. Our SEPIA environments enable an analyst to rapidly configure hybrid environments to pass network traffic and perform, from the outside, like real networks. This provides higher fidelity representations of key network nodes while still leveraging the scalability and cost advantages of simulation tools. The result is to rapidly produce large yet relatively low-cost multi-fidelity SEPIA networks of computers and routers that let analysts quickly investigate threats and test protection approaches.

  7. Excellence in Physics Education Award: Modeling Theory for Physics Instruction

    NASA Astrophysics Data System (ADS)

    Hestenes, David

    2014-03-01

    All humans create mental models to plan and guide their interactions with the physical world. Science has greatly refined and extended this ability by creating and validating formal scientific models of physical things and processes. Research in physics education has found that mental models created from everyday experience are largely incompatible with scientific models. This suggests that the fundamental problem in learning and understanding science is coordinating mental models with scientific models. Modeling Theory has drawn on resources of cognitive science to work out extensive implications of this suggestion and guide development of an approach to science pedagogy and curriculum design called Modeling Instruction. Modeling Instruction has been widely applied to high school physics and, more recently, to chemistry and biology, with noteworthy results.

  8. Equity investigation of attitudinal shifts in introductory physics

    NASA Astrophysics Data System (ADS)

    Traxler, Adrienne; Brewe, Eric

    2015-12-01

    We report on seven years of attitudinal data using the Colorado Learning Attitudes about Science Survey from University Modeling Instruction (UMI) sections of introductory physics at Florida International University. University Modeling Instruction is a curricular and pedagogical transformation of introductory university physics that engages students in building and testing conceptual models in an integrated lab and lecture learning environment. This work expands upon previous studies that reported consistently positive attitude shifts in UMI courses; here, we disaggregate the data by gender and ethnicity to look for any disparities in the pattern of favorable shifts. We find that women and students from statistically underrepresented ethnic groups have gains that are comparable to those of men and students from well-represented ethnic groups on this attitudinal measure, and that this result holds even when interaction effects of gender and ethnicity are included. We conclude with suggestions for future work in UMI courses and for attitudinal equity investigations generally. We encourage researchers to expand their scope beyond simple performance gaps when considering equity concerns, and to avoid relying on a single measure to evaluate student success. Finally, we conjecture that students' social and academic networks are one means by which attitudinal and efficacy beliefs about the course are propagated.

  9. Cabin Environment Physics Risk Model

    NASA Technical Reports Server (NTRS)

    Mattenberger, Christopher J.; Mathias, Donovan Leigh

    2014-01-01

    This paper presents a Cabin Environment Physics Risk (CEPR) model that predicts the time for an initial failure of Environmental Control and Life Support System (ECLSS) functionality to propagate into a hazardous environment and trigger a loss-of-crew (LOC) event. This physics-of failure model allows a probabilistic risk assessment of a crewed spacecraft to account for the cabin environment, which can serve as a buffer to protect the crew during an abort from orbit and ultimately enable a safe return. The results of the CEPR model replace the assumption that failure of the crew critical ECLSS functionality causes LOC instantly, and provide a more accurate representation of the spacecraft's risk posture. The instant-LOC assumption is shown to be excessively conservative and, moreover, can impact the relative risk drivers identified for the spacecraft. This, in turn, could lead the design team to allocate mass for equipment to reduce overly conservative risk estimates in a suboptimal configuration, which inherently increases the overall risk to the crew. For example, available mass could be poorly used to add redundant ECLSS components that have a negligible benefit but appear to make the vehicle safer due to poor assumptions about the propagation time of ECLSS failures.

  10. Equity Investigation of Attitudinal Shifts in Introductory Physics

    ERIC Educational Resources Information Center

    Traxler, Adrienne; Brewe, Eric

    2015-01-01

    We report on seven years of attitudinal data using the Colorado Learning Attitudes about Science Survey from University Modeling Instruction (UMI) sections of introductory physics at Florida International University. University Modeling Instruction is a curricular and pedagogical transformation of introductory university physics that engages…

  11. Topos models for physics and topos theory

    NASA Astrophysics Data System (ADS)

    Wolters, Sander

    2014-08-01

    What is the role of topos theory in the topos models for quantum theory as used by Isham, Butterfield, Döring, Heunen, Landsman, Spitters, and others? In other words, what is the interplay between physical motivation for the models and the mathematical framework used in these models? Concretely, we show that the presheaf topos model of Butterfield, Isham, and Döring resembles classical physics when viewed from the internal language of the presheaf topos, similar to the copresheaf topos model of Heunen, Landsman, and Spitters. Both the presheaf and copresheaf models provide a "quantum logic" in the form of a complete Heyting algebra. Although these algebras are natural from a topos theoretic stance, we seek a physical interpretation for the logical operations. Finally, we investigate dynamics. In particular, we describe how an automorphism on the operator algebra induces a homeomorphism (or isomorphism of locales) on the associated state spaces of the topos models, and how elementary propositions and truth values transform under the action of this homeomorphism. Also with dynamics the focus is on the internal perspective of the topos.

  12. Topos models for physics and topos theory

    SciTech Connect

    Wolters, Sander

    2014-08-15

    What is the role of topos theory in the topos models for quantum theory as used by Isham, Butterfield, Döring, Heunen, Landsman, Spitters, and others? In other words, what is the interplay between physical motivation for the models and the mathematical framework used in these models? Concretely, we show that the presheaf topos model of Butterfield, Isham, and Döring resembles classical physics when viewed from the internal language of the presheaf topos, similar to the copresheaf topos model of Heunen, Landsman, and Spitters. Both the presheaf and copresheaf models provide a “quantum logic” in the form of a complete Heyting algebra. Although these algebras are natural from a topos theoretic stance, we seek a physical interpretation for the logical operations. Finally, we investigate dynamics. In particular, we describe how an automorphism on the operator algebra induces a homeomorphism (or isomorphism of locales) on the associated state spaces of the topos models, and how elementary propositions and truth values transform under the action of this homeomorphism. Also with dynamics the focus is on the internal perspective of the topos.

  13. A Multivariate Model of Physics Problem Solving

    ERIC Educational Resources Information Center

    Taasoobshirazi, Gita; Farley, John

    2013-01-01

    A model of expertise in physics problem solving was tested on undergraduate science, physics, and engineering majors enrolled in an introductory-level physics course. Structural equation modeling was used to test hypothesized relationships among variables linked to expertise in physics problem solving including motivation, metacognitive planning,…

  14. A Multivariate Model of Physics Problem Solving

    ERIC Educational Resources Information Center

    Taasoobshirazi, Gita; Farley, John

    2013-01-01

    A model of expertise in physics problem solving was tested on undergraduate science, physics, and engineering majors enrolled in an introductory-level physics course. Structural equation modeling was used to test hypothesized relationships among variables linked to expertise in physics problem solving including motivation, metacognitive planning,…

  15. Constructing a Model of Physics Expertise

    NASA Astrophysics Data System (ADS)

    Rodriguez, Idaykis; Brewe, Eric; Kramer, Laird

    2010-10-01

    Research on physics expertise has predominantly focused on cognitive differences between physics experts and novices where the novices are high school or introductory college students and the experts are university physics professors or graduate doctoral students. Most physics expertise studies declare the experts to be the physics faculty without justifying this decision. To establish more clearly the characteristics of physics experts, we conducted a qualitative interview pilot study of three university physics professors. The professors each had an hour-long interview where they were asked about their experiences of becoming a physics expert. We present the analysis of the question, `What makes a physics expert?' Analysis of the data resulted in the construction of a model of physics expertise, which indicates that a physics expert is a specific physics expert first, acquires general physics expert characteristics and then becomes an expert in physics or a boundary crosser.

  16. A Gender Study Investigating Physics Self-Efficacy

    ERIC Educational Resources Information Center

    Sawtelle, Vashti

    2011-01-01

    The underrepresentation of women in physics has been well documented and a source of concern for both policy makers and educators. My dissertation focuses on understanding the role self-efficacy plays in retaining students, particularly women, in introductory physics. I use an explanatory mixed methods approach to first investigate quantitatively…

  17. Effects of Proposed Harbor Modifications on Wave Conditions, Harbor Resonance, and Tidal Circulation at Fish Harbor, Los Angeles, California. Physical and Numerical Model Investigations.

    DTIC Science & Technology

    1985-06-01

    Waterways Experiment Station AREA & WORK UNIT NUMBERS Coastal Engineering Research Center P. 0. Box 631, Vicksburg. Mississippi 39180-0631 It. CONTROLLING ...Automated Data Acquisition and Control System were utilized in model operation. A hybrid finite element numerical model (capable of calculating forced...4,750 sq ft, representing about 0.6 square mile in the prototype. A general view of the model is shown in Figure 4. Vertical control for model

  18. Investigations into the mechanical and physical behavior of thermoplastic elastomers

    NASA Astrophysics Data System (ADS)

    Wright, Kathryn Janelle

    This thesis describes investigations into the physical and mechanical characteristics of two commercial thermoplastic elastomer (TPE) systems. Both systems studied exhibit elastomeric behavior similar to more traditional crosslinked elastomers; however, in these TPEs non-conventional polymer architectures and morphologies are used to produce their elastomeric behavior. The two TPEs of interest are ethylene-propylene random copolymers and dynamically vulcanized blends of ethylene-propylene-diene monomer (EPDM) and isotactic polypropylene (iPP). Very few studies have examined the mechanical behavior of these materials in terms of their composition and morphology. As such, the primary goal of this research is to both qualitatively and quantitatively understand the influence of composition and morphology on mechanical behavior. In additional very little information is available that compares their performance with that of crosslinked elastomers. As a result, the secondary goal is to qualitatively compare the mechanical responses of these TPEs with that of their more traditional counterparts. The ethylene-propylene copolymers studied have very high comonomer contents and exhibit slow crystallization kinetics. Their morphology consists of nanoscale crystallites embedded in an amorphous rubbery matrix. These crystallites act as physical crosslinks that allow for elasticity. Slow crystallization causes subsequent changes in mechanical behavior that take place over days and even weeks. Physical responses (e.g., density, crystallization kinetics, and crystal structure) of five copolymer compositions are investigated. Mechanical responses (e.g., stiffness, ductility, yielding, and reversibility) are also examined. Finally, the influence of morphology on deformation is studied using in situ analytical techniques. The EPDM/iPP blends are dynamically vulcanized which produces a complex morphology consisting of chemically crosslinked EPDM domains embedded within a semicrystalline

  19. Testing Physical Models of Passive Membrane Permeation

    PubMed Central

    Leung, Siegfried S. F.; Mijalkovic, Jona; Borrelli, Kenneth; Jacobson, Matthew P.

    2012-01-01

    The biophysical basis of passive membrane permeability is well understood, but most methods for predicting membrane permeability in the context of drug design are based on statistical relationships that indirectly capture the key physical aspects. Here, we investigate molecular mechanics-based models of passive membrane permeability and evaluate their performance against different types of experimental data, including parallel artificial membrane permeability assays (PAMPA), cell-based assays, in vivo measurements, and other in silico predictions. The experimental data sets we use in these tests are diverse, including peptidomimetics, congeneric series, and diverse FDA approved drugs. The physical models are not specifically trained for any of these data sets; rather, input parameters are based on standard molecular mechanics force fields, such as partial charges, and an implicit solvent model. A systematic approach is taken to analyze the contribution from each component in the physics-based permeability model. A primary factor in determining rates of passive membrane permeation is the conformation-dependent free energy of desolvating the molecule, and this measure alone provides good agreement with experimental permeability measurements in many cases. Other factors that improve agreement with experimental data include deionization and estimates of entropy losses of the ligand and the membrane, which lead to size-dependence of the permeation rate. PMID:22621168

  20. Development and assessment of a physics-based simulation model to investigate residential PM2.5 infiltration across the US housing stock

    EPA Science Inventory

    The Lawrence Berkeley National Laboratory Population Impact Assessment Modeling Framework (PIAMF) was expanded to enable determination of indoor PM2.5 concentrations and exposures in a set of 50,000 homes representing the US housing stock. A mass-balance model is used to calculat...

  1. Development and assessment of a physics-based simulation model to investigate residential PM2.5 infiltration across the US housing stock

    EPA Science Inventory

    The Lawrence Berkeley National Laboratory Population Impact Assessment Modeling Framework (PIAMF) was expanded to enable determination of indoor PM2.5 concentrations and exposures in a set of 50,000 homes representing the US housing stock. A mass-balance model is used to calculat...

  2. Investigating a redesigned physics course for future elementary teachers

    NASA Astrophysics Data System (ADS)

    Fracchiolla, Claudia

    There is a growing concern that the number of students graduating with a STEM major in the U.S. is insufficient to fill the growing demand in STEM careers. In order to fulfill that demand, it is important to increase student retention in STEM majors and also to attract more students to pursue careers in those areas. Previous research has indicated that children start losing interest in science at the elementary level because science is taught with a focus on learning vocabulary and ideas rather than learning through inquiry-based techniques. A factor that affects the quality of science education at the elementary level is the preparation of elementary teachers. Many elementary teachers feel unprepared to teach science because they lack adequate content knowledge as well as the pedagogical content knowledge (PCK) for teaching the subject. Previous studies of teacher preparation in science identified some areas with which pre-service teachers need assistance. One of these areas is understanding children's ideas of science. To address that issue, this dissertation investigates whether the use of an instructional approach that teaches physics phenomena along with an understanding of how children think about the physical phenomena promotes changes in students' knowledge of children's ideas and use of those ideas in instructional and assessment strategies. Results indicated that students who were explicitly exposed to knowledge of children's ideas more often incorporated those ideas into their own microteaching and demonstrated higher levels of sophistication of knowledge of children's ideas, instructional strategies, and assessment strategies that incorporated those ideas. This research explores an instructional model for blending physics content and pedagogical content knowledge.

  3. Physics modeling support contract: Final report

    SciTech Connect

    Not Available

    1987-09-30

    This document is the final report for the Physics Modeling Support contract between TRW, Inc. and the Lawrence Livermore National Laboratory for fiscal year 1987. It consists of following projects: TIBER physics modeling and systems code development; advanced blanket modeling task; time dependent modeling; and free electron maser for TIBER II.

  4. Model Formulation for Physics Problem Solving. Draft.

    ERIC Educational Resources Information Center

    Novak, Gordon S., Jr.

    The major task in solving a physics problem is to construct an appropriate model of the problem in terms of physical principles. The functions performed by such a model, the information which needs to be represented, and the knowledge used in selecting and instantiating an appropriate model are discussed. An example of a model for a mechanics…

  5. Chemical, physical and tribological investigation of polymercaptanized soybean oil

    USDA-ARS?s Scientific Manuscript database

    Polymercaptanized soybean oil (PMSO) was investigated for its chemical, physical and tribological properties relative to soybean oil (SO) and also as a potential multi-functional lubricant additive in high oleic sunflower oil (HOSuO). Analytical investigations showed that PMSO is obtained by convers...

  6. Physical modeling of Tibetan bowls

    NASA Astrophysics Data System (ADS)

    Antunes, Jose; Inacio, Octavio

    2001-05-01

    Tibetan bowls produce rich penetrating sounds, used in musical contexts and to induce a state of relaxation for meditation or therapy purposes. To understand the dynamics of these instruments under impact and rubbing excitation, we developed a simulation method based on the modal approach, following our previous papers on physical modeling of plucked/bowed strings and impacted/bowed bars. This technique is based on a compact representation of the system dynamics, in terms of the unconstrained bowl modes. Nonlinear contact/friction interaction forces, between the exciter (puja) and the bowl, are computed at each time step and projected on the bowl modal basis, followed by step integration of the modal equations. We explore the behavior of two different-sized bowls, for extensive ranges of excitation conditions (contact/friction parameters, normal force, and tangential puja velocity). Numerical results and experiments show that various self-excited motions may arise depending on the playing conditions and, mainly, on the contact/friction interaction parameters. Indeed, triggering of a given bowl modal frequency mainly depends on the puja material. Computed animations and experiments demonstrate that self-excited modes spin, following the puja motion. Accordingly, the sensed pressure field pulsates, with frequency controlled by the puja spinning velocity and the spatial pattern of the singing mode.

  7. Physical modeling of Tibetan bowls

    NASA Astrophysics Data System (ADS)

    Antunes, Jose; Inacio, Octavio

    2004-05-01

    Tibetan bowls produce rich penetrating sounds, used in musical contexts and to induce a state of relaxation for meditation or therapy purposes. To understand the dynamics of these instruments under impact and rubbing excitation, we developed a simulation method based on the modal approach, following our previous papers on physical modeling of plucked/bowed strings and impacted/bowed bars. This technique is based on a compact representation of the system dynamics, in terms of the unconstrained bowl modes. Nonlinear contact/friction interaction forces, between the exciter (puja) and the bowl, are computed at each time step and projected on the bowl modal basis, followed by step integration of the modal equations. We explore the behavior of two different-sized bowls, for extensive ranges of excitation conditions (contact/friction parameters, normal force, and tangential puja velocity). Numerical results and experiments show that various self-excited motions may arise depending on the playing conditions and, mainly, on the contact/friction interaction parameters. Indeed, triggering of a given bowl modal frequency mainly depends on the puja material. Computed animations and experiments demonstrate that self-excited modes spin, following the puja motion. Accordingly, the sensed pressure field pulsates, with frequency controlled by the puja spinning velocity and the spatial pattern of the singing mode.

  8. Shape Models and Physical Properties of Asteroids

    NASA Astrophysics Data System (ADS)

    Santana-Ros, T.; Dudziński, G.; Bartczak, P.

    Despite the large amount of high quality data generated in recent space encounters with asteroids, the majority of our knowledge about these objects comes from ground based observations. Asteroids travelling in orbits that are potentially hazardous for the Earth form an especially interesting group to be studied. In order to predict their orbital evolution, it is necessary to investigate their physical properties. This paper briefly describes the data requirements and different techniques used to solve the lightcurve inversion problem. Although photometry is the most abundant type of observational data, models of asteroids can be obtained using various data types and techniques. We describe the potential of radar imaging and stellar occultation timings to be combined with disk-integrated photometry in order to reveal information about physical properties of asteroids.

  9. Guest investigator program study: Physics of equatorial plasma bubbles

    NASA Technical Reports Server (NTRS)

    Tsunoda, Roland T.

    1994-01-01

    Plasma bubbles are large-scale (10 to 100 km) depletions in plasma density found in the night-time equatorial ionosphere. Their formation has been found to entail the upward transport of plasma over hundreds of kilometers in altitude, suggesting that bubbles play significant roles in the physics of many of the diverse and unique features found in the low-latitude ionosphere. In the simplest scenario, plasma bubbles appear first as perturbations in the bottomside F layer, which is linearly unstable to the gravitationally driven Rayleigh-Taylor instability. Once initiated, bubbles develop upward through the peak of the F layer into its topside (sometimes to altitudes in excess of 1000 km), a behavior predicted by the nonlinear form of the same instability. While good general agreement has been found between theory and observations, little is known about the detailed physics associated with plasma bubbles. Our research activity centered around two topics: the shape of plasma bubbles and associated electric fields, and the day-to-day variability in the occurrence of plasma bubbles. The first topic was pursued because of a divergence in view regarding the nonlinear physics associated with plasma bubble development. While the development of perturbations in isodensity contours in the bottomside F layer into plasma bubbles is well accepted, some believed bubbles to be cylinder-like closed regions of depleted plasma density that floated upward leaving a turbulent wake behind them (e.g., Woodman and LaHoz, 1976; Ott, 1978; Kelley and Ott, 1978). Our results, summarized in a paper submitted to the Journal of Geophysical Research, consisted of incoherent scatter radar measurements that showed unambiguously that the depleted region is wedgelike and not cylinderlike, and a case study and modeling of SM-D electric field instrument (EFI) measurements that showed that the absence of electric-field perturbations outside the plasma-depleted region is a distinct signature of wedge

  10. From metallurgy to modelling of electrical steels: A multiple approach to their behaviour and use based on physics and experimental investigations

    NASA Astrophysics Data System (ADS)

    Cornut, B.; Kedous-Lebouc, A.; Waeckerlé, Th.

    1996-07-01

    Research on SiFe is a busy field which corresponds to the main soft magnetic materials interests of the Laboratoire d'Electrotechnique de Grenoble. Three mutually enriched areas are being explored: metallurgical research towards the production of cube textured sheets, instrumentation research allowing precise measurements of magnetic properties under extreme conditions, and models of magnetization vectorial laws or loss prediction to be included in computer aided design.

  11. NUMERICAL MODELING OF FINE SEDIMENT PHYSICAL PROCESSES.

    USGS Publications Warehouse

    Schoellhamer, David H.

    1985-01-01

    Fine sediment in channels, rivers, estuaries, and coastal waters undergo several physical processes including flocculation, floc disruption, deposition, bed consolidation, and resuspension. This paper presents a conceptual model and reviews mathematical models of these physical processes. Several general fine sediment models that simulate some of these processes are reviewed. These general models do not directly simulate flocculation and floc disruption, but the conceptual model and existing functions are shown to adequately model these two processes for one set of laboratory data.

  12. Statistical physical models of cellular motility

    NASA Astrophysics Data System (ADS)

    Banigan, Edward J.

    Cellular motility is required for a wide range of biological behaviors and functions, and the topic poses a number of interesting physical questions. In this work, we construct and analyze models of various aspects of cellular motility using tools and ideas from statistical physics. We begin with a Brownian dynamics model for actin-polymerization-driven motility, which is responsible for cell crawling and "rocketing" motility of pathogens. Within this model, we explore the robustness of self-diffusiophoresis, which is a general mechanism of motility. Using this mechanism, an object such as a cell catalyzes a reaction that generates a steady-state concentration gradient that propels the object in a particular direction. We then apply these ideas to a model for depolymerization-driven motility during bacterial chromosome segregation. We find that depolymerization and protein-protein binding interactions alone are sufficient to robustly pull a chromosome, even against large loads. Next, we investigate how forces and kinetics interact during eukaryotic mitosis with a many-microtubule model. Microtubules exert forces on chromosomes, but since individual microtubules grow and shrink in a force-dependent way, these forces lead to bistable collective microtubule dynamics, which provides a mechanism for chromosome oscillations and microtubule-based tension sensing. Finally, we explore kinematic aspects of cell motility in the context of the immune system. We develop quantitative methods for analyzing cell migration statistics collected during imaging experiments. We find that during chronic infection in the brain, T cells run and pause stochastically, following the statistics of a generalized Levy walk. These statistics may contribute to immune function by mimicking an evolutionarily conserved efficient search strategy. Additionally, we find that naive T cells migrating in lymph nodes also obey non-Gaussian statistics. Altogether, our work demonstrates how physical

  13. Multi-physics modelling contributions to investigate the atmospheric cosmic rays on the single event upset sensitivity along the scaling trend of CMOS technologies.

    PubMed

    Hubert, G; Regis, D; Cheminet, A; Gatti, M; Lacoste, V

    2014-10-01

    Particles originating from primary cosmic radiation, which hit the Earth's atmosphere give rise to a complex field of secondary particles. These particles include neutrons, protons, muons, pions, etc. Since the 1980s it has been known that terrestrial cosmic rays can penetrate the natural shielding of buildings, equipment and circuit package and induce soft errors in integrated circuits. Recently, research has shown that commercial static random access memories are now so small and sufficiently sensitive that single event upsets (SEUs) may be induced from the electronic stopping of a proton. With continued advancements in process size, this downward trend in sensitivity is expected to continue. Then, muon soft errors have been predicted for nano-electronics. This paper describes the effects in the specific cases such as neutron-, proton- and muon-induced SEU observed in complementary metal-oxide semiconductor. The results will allow investigating the technology node sensitivity along the scaling trend. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Evaluating a Model of Youth Physical Activity

    ERIC Educational Resources Information Center

    Heitzler, Carrie D.; Lytle, Leslie A.; Erickson, Darin J.; Barr-Anderson, Daheia; Sirard, John R.; Story, Mary

    2010-01-01

    Objective: To explore the relationship between social influences, self-efficacy, enjoyment, and barriers and physical activity. Methods: Structural equation modeling examined relationships between parent and peer support, parent physical activity, individual perceptions, and objectively measured physical activity using accelerometers among a…

  15. Investigating Visually Disabled Students' Attitudes about Physical Education and Sport

    ERIC Educational Resources Information Center

    Dalbudak, Ibrahim; Gürkan, Alper C.; Yigit, Sih Mehmet; Kargun, Mehmet; Hazar, Gürkan; Dorak, Feridun

    2016-01-01

    This study aims to investigate visually disabled students', who study in the level of primary education, high school, university, attitudes about physical education and sport in terms of different variables. Totally 100 visually disabled students who are individual and team athletes and study in Izmir, (8 visually disabled athletes study in…

  16. Multiscale Atmospheric Physics Modeled by Cumulant Expansions

    NASA Astrophysics Data System (ADS)

    Marston, Brad; Chini, Greg

    2014-03-01

    We investigate a systematic and physically based approach to modeling subgrid physics statistically with the use of an expansion in equal-time cumulants. To accomplish this we replace the zonal average employed in previous work with a low-pass filter that separates small and large scales in the zonal direction. The statistics are non-local, inhomogeneous, and anisotropic; the sole approximation is the neglect of 3-point and higher correlation functions. The closure respects the conservation of energy, enstrophy, and angular momentum. An advantage of the formulation is that correlations between large and small scale processes are treated explicitly without the introduction of phenomenological parameterizations. The approach is tested against full numerical simulation of idealized 1- and 2-layer models of the atmospheric general circulation and shown to yield accurate low-order statistics. (The computer model used to perform these tests runs on OS X and is publicly available.) We identify important multiscale interactions and discuss the computational cost of the new scheme. Supported in part by NSF DMR-1306806 and CCF-1048701.

  17. Comprehensive Physical Education Program Model

    ERIC Educational Resources Information Center

    Kamiya, Artie

    2005-01-01

    In 2004, the Wake County Public School System (North Carolina) received $1.3 million as one of 237 national winners of the $70 million federal Carol M. White Physical Education Program (PEP) Grant competition. The PEP Grant program is funded by the U.S. Department of Education and provides monies to school districts able to demonstrate the…

  18. Comprehensive Physical Education Program Model

    ERIC Educational Resources Information Center

    Kamiya, Artie

    2005-01-01

    In 2004, the Wake County Public School System (North Carolina) received $1.3 million as one of 237 national winners of the $70 million federal Carol M. White Physical Education Program (PEP) Grant competition. The PEP Grant program is funded by the U.S. Department of Education and provides monies to school districts able to demonstrate the…

  19. Investigating physics teaching and learning in a university setting

    NASA Astrophysics Data System (ADS)

    Guisasola, Jenaro; De Cock, Mieke; Kanim, Stephen; Ivanjek, Lana; Zuza, Kristina; Bollen, Laurens; van Kampen, Paul

    2016-05-01

    Most of the initiatives taken by the European Community and by other countries internationally in the field of science education focus on elementary and secondary levels of education, and relatively few reports have analysed the state of science education in higher education. However, research in science education, and in particular in physics education, has shown repeatedly that the way teachers teach in elementary and secondary school is strongly influenced by their own prior experience as university students. The education that future professionals, such as scientists, engineers and science teachers, receive at the university is worthy of study, because it allows us to investigate student learning relatively independently of developmental issues, and because of the more rigorous treatment of physics topics at the university level. For these reasons, it seems appropriate to identify, analyse and provide solutions to the problems of teaching and learning related to the university physics curriculum. In this symposium, we present examples of physics education research from different countries that is focused on physics topics

  20. Modelling biological complexity: a physical scientist's perspective.

    PubMed

    Coveney, Peter V; Fowler, Philip W

    2005-09-22

    We discuss the modern approaches of complexity and self-organization to understanding dynamical systems and how these concepts can inform current interest in systems biology. From the perspective of a physical scientist, it is especially interesting to examine how the differing weights given to philosophies of science in the physical and biological sciences impact the application of the study of complexity. We briefly describe how the dynamics of the heart and circadian rhythms, canonical examples of systems biology, are modelled by sets of nonlinear coupled differential equations, which have to be solved numerically. A major difficulty with this approach is that all the parameters within these equations are not usually known. Coupled models that include biomolecular detail could help solve this problem. Coupling models across large ranges of length- and time-scales is central to describing complex systems and therefore to biology. Such coupling may be performed in at least two different ways, which we refer to as hierarchical and hybrid multiscale modelling. While limited progress has been made in the former case, the latter is only beginning to be addressed systematically. These modelling methods are expected to bring numerous benefits to biology, for example, the properties of a system could be studied over a wider range of length- and time-scales, a key aim of systems biology. Multiscale models couple behaviour at the molecular biological level to that at the cellular level, thereby providing a route for calculating many unknown parameters as well as investigating the effects at, for example, the cellular level, of small changes at the biomolecular level, such as a genetic mutation or the presence of a drug. The modelling and simulation of biomolecular systems is itself very computationally intensive; we describe a recently developed hybrid continuum-molecular model, HybridMD, and its associated molecular insertion algorithm, which point the way towards the

  1. Modelling biological complexity: a physical scientist's perspective

    PubMed Central

    Coveney, Peter V; Fowler, Philip W

    2005-01-01

    We discuss the modern approaches of complexity and self-organization to understanding dynamical systems and how these concepts can inform current interest in systems biology. From the perspective of a physical scientist, it is especially interesting to examine how the differing weights given to philosophies of science in the physical and biological sciences impact the application of the study of complexity. We briefly describe how the dynamics of the heart and circadian rhythms, canonical examples of systems biology, are modelled by sets of nonlinear coupled differential equations, which have to be solved numerically. A major difficulty with this approach is that all the parameters within these equations are not usually known. Coupled models that include biomolecular detail could help solve this problem. Coupling models across large ranges of length- and time-scales is central to describing complex systems and therefore to biology. Such coupling may be performed in at least two different ways, which we refer to as hierarchical and hybrid multiscale modelling. While limited progress has been made in the former case, the latter is only beginning to be addressed systematically. These modelling methods are expected to bring numerous benefits to biology, for example, the properties of a system could be studied over a wider range of length- and time-scales, a key aim of systems biology. Multiscale models couple behaviour at the molecular biological level to that at the cellular level, thereby providing a route for calculating many unknown parameters as well as investigating the effects at, for example, the cellular level, of small changes at the biomolecular level, such as a genetic mutation or the presence of a drug. The modelling and simulation of biomolecular systems is itself very computationally intensive; we describe a recently developed hybrid continuum-molecular model, HybridMD, and its associated molecular insertion algorithm, which point the way towards the

  2. Are Physical Education Majors Models for Fitness?

    ERIC Educational Resources Information Center

    Kamla, James; Snyder, Ben; Tanner, Lori; Wash, Pamela

    2012-01-01

    The National Association of Sport and Physical Education (NASPE) (2002) has taken a firm stance on the importance of adequate fitness levels of physical education teachers stating that they have the responsibility to model an active lifestyle and to promote fitness behaviors. Since the NASPE declaration, national initiatives like Let's Move…

  3. Investigation of physical parameters in stellar flares observed by GINGA

    NASA Technical Reports Server (NTRS)

    Stern, Robert A.

    1994-01-01

    This program involves analysis and interpretation of results from GINGA Large Area Counter (LAC) observations from a group of large stellar x-ray flares. All LAC data are re-extracted using the standard Hayashida method of LAC background subtraction and analyzed using various models available with the XSPEC spectral fitting program. Temperature-emission measure histories are available for a total of 5 flares observed by GINGA. These will be used to compare physical parameters of these flares with solar and stellar flare models.

  4. Investigation of physical parameters in stellar flares observed by GINGA

    NASA Technical Reports Server (NTRS)

    Stern, Robert A.

    1994-01-01

    This program involves analysis and interpretation of results from GINGA Large Area Counter (LAC) observations from a group of large stellar X-ray flares. All LAC data are re-extracted using the standard Hayashida method of LAC background subtraction and analyzed using various models available with the XSPEC spectral fitting program.Temperature-emission measure histories are available for a total of 5 flares observed by GINGA. These will be used to compare physical parameters of these flares with solar and stellar flare models.

  5. Bridging physics and biology teaching through modeling

    NASA Astrophysics Data System (ADS)

    Hoskinson, Anne-Marie; Couch, Brian A.; Zwickl, Benjamin M.; Hinko, Kathleen A.; Caballero, Marcos D.

    2014-05-01

    As the frontiers of biology become increasingly interdisciplinary, the physics education community has engaged in ongoing efforts to make physics classes more relevant to life science majors. These efforts are complicated by the many apparent differences between these fields, including the types of systems that each studies, the behavior of those systems, the kinds of measurements that each makes, and the role of mathematics in each field. Nonetheless, physics and biology are both sciences that rely on observations and measurements to construct models of the natural world. In this article, we propose that efforts to bridge the teaching of these two disciplines must emphasize shared scientific practices, particularly scientific modeling. We define modeling using language common to both disciplines and highlight how an understanding of the modeling process can help reconcile apparent differences between the teaching of physics and biology. We elaborate on how models can be used for explanatory, predictive, and functional purposes and present common models from each discipline demonstrating key modeling principles. By framing interdisciplinary teaching in the context of modeling, we aim to bridge physics and biology teaching and to equip students with modeling competencies applicable in any scientific discipline.

  6. Modeling Physics with Easy Java Simulations

    ERIC Educational Resources Information Center

    Christian, Wolfgang; Esquembre, Francisco

    2007-01-01

    Modeling has been shown to correct weaknesses of traditional instruction by engaging students in the design of physical models to describe, explain, and predict phenomena. Although the modeling method can be used without computers, the use of computers allows students to study problems that are difficult and time consuming, to visualize their…

  7. Modeling Physics with Easy Java Simulations

    ERIC Educational Resources Information Center

    Christian, Wolfgang; Esquembre, Francisco

    2007-01-01

    Modeling has been shown to correct weaknesses of traditional instruction by engaging students in the design of physical models to describe, explain, and predict phenomena. Although the modeling method can be used without computers, the use of computers allows students to study problems that are difficult and time consuming, to visualize their…

  8. The trinucleons: Physical observables and model properties

    SciTech Connect

    Gibson, B.F.

    1992-01-01

    Our progress in understanding the properties of {sup 3}H and {sup 3}He in terms of a nonrelativistic Hamiltonian picture employing realistic nuclear forces is reviewed. Trinucleon model properties are summarized for a number of contemporary force models, and predictions for physical observables are presented. Disagreement between theoretical model results and experimental results are highlighted.

  9. The trinucleons: Physical observables and model properties

    SciTech Connect

    Gibson, B.F.

    1992-05-01

    Our progress in understanding the properties of {sup 3}H and {sup 3}He in terms of a nonrelativistic Hamiltonian picture employing realistic nuclear forces is reviewed. Trinucleon model properties are summarized for a number of contemporary force models, and predictions for physical observables are presented. Disagreement between theoretical model results and experimental results are highlighted.

  10. An investigation using Spectroscopic Ellipsometery in Bio-Physical

    NASA Astrophysics Data System (ADS)

    Pfeiffer, Galen; Thompson, Daniel; Berberov, Emil; Woollam, John; Bleiweiss, Michael; Datta, Timir

    2001-03-01

    The present work is an investigation of bio-physical systems using spectroscopic ellipsometry (SE), with wavelengths ranging from deep-ultraviolet to the far infrared. Recent advances in SE hardware, software and data analysis permit rapid, non-contact investigation of physical properties of nano-dimensional soft-material films and interfaces such as bio-films under liquids. The kinetics of attachment, layer thickness, density of coverage, and identification of interfacial chemistry of proteins, for example, on surfaces is of practical and fundamental importance in biology and medicine, and are potentially measurable by SE. Our initial findings determine adsorption rates of Bovine Serum Albumin (BSA) and other bio-films on gold and polystyrene substrates, as well as their spatial distributions. We were also able to identify attachment of a 2.5 nm layer of the diarrhea causing E. coli enterotoxin (LT) to ganglioside (GM1) receptor, potentially simplifying and providing more information to standard enzyme linked immuno sorbent assay (ELISA) methods. Results of studies of several different bio-physical systems using SE will be discussed.

  11. The Standard Model of Nuclear Physics

    NASA Astrophysics Data System (ADS)

    Detmold, William

    2015-04-01

    At its core, nuclear physics, which describes the properties and interactions of hadrons, such as protons and neutrons, and atomic nuclei, arises from the Standard Model of particle physics. However, the complexities of nuclei result in severe computational difficulties that have historically prevented the calculation of central quantities in nuclear physics directly from this underlying theory. The availability of petascale (and prospect of exascale) high performance computing is changing this situation by enabling us to extend the numerical techniques of lattice Quantum Chromodynamics (LQCD), applied successfully in particle physics, to the more intricate dynamics of nuclear physics. In this talk, I will discuss this revolution and the emerging understanding of hadrons and nuclei within the Standard Model.

  12. Developing + Using Models in Physics

    ERIC Educational Resources Information Center

    Campbell, Todd; Neilson, Drew; Oh, Phil Seok

    2013-01-01

    Of the eight practices of science identified in "A Framework for K-12 Science Education" (NRC 2012), helping students develop and use models has been identified by many as an anchor (Schwarz and Passmore 2012; Windschitl 2012). In instruction, disciplinary core ideas, crosscutting concepts, and scientific practices can be meaningfully…

  13. Developing + Using Models in Physics

    ERIC Educational Resources Information Center

    Campbell, Todd; Neilson, Drew; Oh, Phil Seok

    2013-01-01

    Of the eight practices of science identified in "A Framework for K-12 Science Education" (NRC 2012), helping students develop and use models has been identified by many as an anchor (Schwarz and Passmore 2012; Windschitl 2012). In instruction, disciplinary core ideas, crosscutting concepts, and scientific practices can be meaningfully…

  14. Physics of the Quark Model

    ERIC Educational Resources Information Center

    Young, Robert D.

    1973-01-01

    Discusses the charge independence, wavefunctions, magnetic moments, and high-energy scattering of hadrons on the basis of group theory and nonrelativistic quark model with mass spectrum calculated by first-order perturbation theory. The presentation is explainable to advanced undergraduate students. (CC)

  15. Physics of the Quark Model

    ERIC Educational Resources Information Center

    Young, Robert D.

    1973-01-01

    Discusses the charge independence, wavefunctions, magnetic moments, and high-energy scattering of hadrons on the basis of group theory and nonrelativistic quark model with mass spectrum calculated by first-order perturbation theory. The presentation is explainable to advanced undergraduate students. (CC)

  16. PHYSICAL MODELING OF CONTRACTED FLOW.

    USGS Publications Warehouse

    Lee, Jonathan K.

    1987-01-01

    Experiments on steady flow over uniform grass roughness through centered single-opening contractions were conducted in the Flood Plain Simulation Facility at the U. S. Geological Survey's Gulf Coast Hydroscience Center near Bay St. Louis, Miss. The experimental series was designed to provide data for calibrating and verifying two-dimensional, vertically averaged surface-water flow models used to simulate flow through openings in highway embankments across inundated flood plains. Water-surface elevations, point velocities, and vertical velocity profiles were obtained at selected locations for design discharges ranging from 50 to 210 cfs. Examples of observed water-surface elevations and velocity magnitudes at basin cross-sections are presented.

  17. Assessment of A-level physics (Nuffield) investigations

    NASA Astrophysics Data System (ADS)

    Jakeways, Robin

    1986-07-01

    Advanced-level physics (Nuffield) investigations consist of short experimental projects which are carried out by students in the second year of the course. Each student selects a topic for study, either independently or with some advice from a teacher, and then, during a prescribed period, carries out experimental work which is subsequently written up and assessed by the teacher or teachers. The prescribed time for carrying out the whole exercise is around 20 hours and, in this time, the candidates are expected to prepare for the project, devise and carry out experiments, analyse the data and then complete a written account. The author gives an account of the assessment criteria used.

  18. Modelling Mathematical Reasoning in Physics Education

    NASA Astrophysics Data System (ADS)

    Uhden, Olaf; Karam, Ricardo; Pietrocola, Maurício; Pospiech, Gesche

    2012-04-01

    Many findings from research as well as reports from teachers describe students' problem solving strategies as manipulation of formulas by rote. The resulting dissatisfaction with quantitative physical textbook problems seems to influence the attitude towards the role of mathematics in physics education in general. Mathematics is often seen as a tool for calculation which hinders a conceptual understanding of physical principles. However, the role of mathematics cannot be reduced to this technical aspect. Hence, instead of putting mathematics away we delve into the nature of physical science to reveal the strong conceptual relationship between mathematics and physics. Moreover, we suggest that, for both prospective teaching and further research, a focus on deeply exploring such interdependency can significantly improve the understanding of physics. To provide a suitable basis, we develop a new model which can be used for analysing different levels of mathematical reasoning within physics. It is also a guideline for shifting the attention from technical to structural mathematical skills while teaching physics. We demonstrate its applicability for analysing physical-mathematical reasoning processes with an example.

  19. Modeling theory applied: Modeling Instruction in introductory physics

    NASA Astrophysics Data System (ADS)

    Brewe, Eric

    2008-12-01

    Modeling Instruction is a pedagogical approach which has been widely and successfully employed in high school physics instruction but is not commonly used at the university level. The goal of this paper is to describe the nature of Modeling Instruction at the university level and to clarify the role of models in physics instruction. A university physics class is described as it progresses through a typical modeling cycle, Introduction and Representation, Coordination of Representations, Abstraction and Generalization, and Application and Refinement. The benefits of modeling instruction are discussed.

  20. Tracking LNOx Downwind to Investigate Driving Production Physics

    NASA Astrophysics Data System (ADS)

    Lapierre, J. L.; Pusede, S.

    2016-12-01

    Emissions of nitrogen oxides (NOx) influence atmospheric oxidation chemistry and drive ozone production. In the upper troposphere, lightning production (LNOx) is believed to contribute as much as 70% of the total NOx. Therefore, accurate, process-driven constraints on LNOx are required to understand the global NOx and ozone burden. However, estimates of the amount of NOx produced per lightning flash remain highly uncertain, ranging across multiple orders of magnitude ( 10-1000 moles NOx/flash). Satellite measurements provide unique advantages to study LNOx due to their extensive spatial coverage of the Earth, but despite the mechanism by which lightning produces NOx being generally known, correlations between satellite NO2 and measured flash counts are often observed to be poor. Here, we combine NO2 measurements from the Ozone Monitoring Instrument (OMI), lightning data from the National Lightning Detection Network (NLDN), and wind data from the NCEP North American Regional Reanalysis (NARR) over a 4 year period (2012-2015) to study observed relationships between the occurrence and physical characteristics of lightning (e.g., intracloud/cloud-to-ground ratio, polarity, peak current, and multiplicity) with elevated NO2 columns. We investigate the observed spatial mismatch between high flash rates and elevated upper tropospheric NO2, highlight a number of individual storms as case studies, and describe the winds and chemistry that dislocate LNOx from storms. We then use these new constraints on LNOx to investigate the physical drivers of LNOx production rates.

  1. Physical Modelling of Sedimentary Basin

    SciTech Connect

    Yuen, David A.

    2003-04-24

    The main goals of the first three years have been achieved, i.e., the development of particle-based and continuum-based algorithms for cross-scaleup-scale analysis of complex fluid flows. The U. Minnesota team has focused on particle-based methods, wavelets (Rustad et al., 2001) and visualization and has had great success with the dissipative and fluid particle dynamics algorithms, as applied to colloidal, polymeric and biological systems, wavelet filtering and visualization endeavors. We have organized two sessions in nonlinear geophysics at the A.G.U. Fall Meeting (2000,2002), which have indeed synergetically stimulated the community and promoted cross-disciplinary efforts in the geosciences. The LANL team has succeeded with continuum-based algorithms, in particular, fractal interpolating functions (fif). These have been applied to 1-D flow and transport equations (Travis, 2000; 2002) as a proof of principle, providing solutions that capture dynamics at all scales. In addition, the fif representations can be integrated to provide sub-grid-scale homogenization, which can be used in more traditional finite difference or finite element solutions of porous flow and transport. Another useful tool for fluid flow problems is the ability to solve inverse problems, that is, given present-time observations of a fluid flow, what was the initial state of that fluid system? We have demonstrated this capability for a large-scale problem of 3-D flow in the Earth's crust (Bunge, Hagelberg & Travis, 2002). Use of the adjoint method for sensitivity analysis (Marchuk, 1995) to compute derivatives of models makes the large-scale inversion feasible in 4-D, , space and time. Further, a framework for simulating complex fluid flow in the Earth's crust has been implemented (Dutrow et al, 2001). The remaining task of the first three-year campaign is to extend the implementation of the fif formalism to our 2-D and 3-D computer codes, which is straightforward, but involved.

  2. Particle physics and cosmology in supersymmetric models

    NASA Astrophysics Data System (ADS)

    Morrissey, David Edgar

    The Standard Model (SM) of particle physics provides an excellent description of the elementary particle interactions observed in particle collider experiments, but the model does less well when it is applied to cosmology. Recent measurements of the Universe over very large distances indicate the existence of non-luminous dark matter and an excess of baryons over anti-baryons. The SM is unable to account for either of these results, implying that an extension of the SM description is needed. One such extension is supersymmetry. Within the minimal supersymmetric version of the SM, the MSSM, the lightest superpartner particle can make up the dark matter, and the baryon asymmetry can be generated by the mechanism of electroweak baryogenesis (EWBG). In this work, we examine these issues together in order to find out whether the MSSM can account for both of them simultaneously. We find that the MSSM can explain both the baryon asymmetry and the dark matter, but only over a very constrained region of the model parameter space. The strongest constraints on this scenario come from the lower bound on the Higgs boson mass, and the upper bound on the electric dipole moment of the electron. Moreover, upcoming experiments will probe the remaining allowed parameter space in the near future. Some of these constraints may be relaxed by going beyond the MSSM. With this in mind, we also investigate the nMSSM, a minimal singlet extension of the MSSM. We find that this model can also explain both the dark matter and the baryon asymmetry.

  3. Investigating elementary education and physical therapy majors' perceptions of an inquiry-based physics content course

    NASA Astrophysics Data System (ADS)

    Hilton, John Martin

    This study investigates why physical therapy assistant majors engage and perform better than elementary education majors in an inquiry-based conceptual physics course at Mid-Atlantic Community College. The students from each major are demographically similar, both courses are similar in depth and structure, and each course supports the students' program. However, there is an observed difference in the levels of engagement with the curriculum and performance on writing-based assessments between the two groups. To explore possible explanations for the difference, I examine students' affinity for science, their beliefs about the nature of science and scientific knowledge in the classroom, and their perception of the usefulness of science to their program. During semi-structured interviews, students from both majors displayed nearly identical weak affinities for science, epistemological beliefs, and uncertainty about the usefulness of the class. However, the physical therapy majors' ability to see the relevance of the physics course experience to their program enhanced their interest and motivation. In contrast, the elementary education students do not see connections between the course and their program, and do not see a purpose for their learning of physics content. To improve the program, I propose a two-pronged approach - designing a faded-scaffolded-inquiry approach for both classes, and developing a field-based/seminar class for the elementary education majors. The scaffolded inquiry will help both groups develop better orientations toward lab activities, and the structured observations and reflection will help the elementary group connect the material to their program.

  4. [Investigations in dynamics of gauge theories in theoretical particle physics

    SciTech Connect

    Not Available

    1993-02-01

    The major theme of the theoretical physics research conducted under DOE support over the past several years has been within the rubric of the standard model, and concerned the interplay between symmetries and dynamics. The research was thus carried out mostly in the context of gauge field theories, and usually in the presence of chiral fermions. Dynamical symmetry breaking was examined both from the point of view of perturbation theory, as well as from non-perturbative techniques associated with certain characteristic features of specific theories. Among the topics of research were: the implications of abelian and non-abelian anomalies on the spectrum and possible dynamical symmetry breaking in any theory, topological and conformal properties of quantum fields in two and higher dimensions, the breaking of global chiral symmetries by vector-like gauge theories such as QCD, the phenomenological implications of a strongly interacting Higgs sector in the standard model, and the application of soliton ideas to the physics to be explored at the SSC.

  5. Composing Models of Geographic Physical Processes

    NASA Astrophysics Data System (ADS)

    Hofer, Barbara; Frank, Andrew U.

    Processes are central for geographic information science; yet geographic information systems (GIS) lack capabilities to represent process related information. A prerequisite to including processes in GIS software is a general method to describe geographic processes independently of application disciplines. This paper presents such a method, namely a process description language. The vocabulary of the process description language is derived formally from mathematical models. Physical processes in geography can be described in two equivalent languages: partial differential equations or partial difference equations, where the latter can be shown graphically and used as a method for application specialists to enter their process models. The vocabulary of the process description language comprises components for describing the general behavior of prototypical geographic physical processes. These process components can be composed by basic models of geographic physical processes, which is shown by means of an example.

  6. Simplified Models for LHC New Physics Searches

    SciTech Connect

    Alves, Daniele; Arkani-Hamed, Nima; Arora, Sanjay; Bai, Yang; Baumgart, Matthew; Berger, Joshua; Buckley, Matthew; Butler, Bart; Chang, Spencer; Cheng, Hsin-Chia; Cheung, Clifford; Chivukula, R.Sekhar; Cho, Won Sang; Cotta, Randy; D'Alfonso, Mariarosaria; El Hedri, Sonia; Essig, Rouven,; Evans, Jared A.; Fitzpatrick, Liam; Fox, Patrick; Franceschini, Roberto; /more authors..

    2012-06-01

    This document proposes a collection of simplified models relevant to the design of new-physics searches at the LHC and the characterization of their results. Both ATLAS and CMS have already presented some results in terms of simplified models, and we encourage them to continue and expand this effort, which supplements both signature-based results and benchmark model interpretations. A simplified model is defined by an effective Lagrangian describing the interactions of a small number of new particles. Simplified models can equally well be described by a small number of masses and cross-sections. These parameters are directly related to collider physics observables, making simplified models a particularly effective framework for evaluating searches and a useful starting point for characterizing positive signals of new physics. This document serves as an official summary of the results from the 'Topologies for Early LHC Searches' workshop, held at SLAC in September of 2010, the purpose of which was to develop a set of representative models that can be used to cover all relevant phase space in experimental searches. Particular emphasis is placed on searches relevant for the first {approx} 50-500 pb{sup -1} of data and those motivated by supersymmetric models. This note largely summarizes material posted at http://lhcnewphysics.org/, which includes simplified model definitions, Monte Carlo material, and supporting contacts within the theory community. We also comment on future developments that may be useful as more data is gathered and analyzed by the experiments.

  7. Simplified models for LHC new physics searches

    NASA Astrophysics Data System (ADS)

    Alves, Daniele; Arkani-Hamed, Nima; Arora, Sanjay; Bai, Yang; Baumgart, Matthew; Berger, Joshua; Buckley, Matthew; Butler, Bart; Chang, Spencer; Cheng, Hsin-Chia; Cheung, Clifford; Sekhar Chivukula, R.; Cho, Won Sang; Cotta, Randy; D'Alfonso, Mariarosaria; El Hedri, Sonia; Essig (Editor, Rouven; Evans, Jared A.; Fitzpatrick, Liam; Fox, Patrick; Franceschini, Roberto; Freitas, Ayres; Gainer, James S.; Gershtein, Yuri; Gray, Richard; Gregoire, Thomas; Gripaios, Ben; Gunion, Jack; Han, Tao; Haas, Andy; Hansson, Per; Hewett, JoAnne; Hits, Dmitry; Hubisz, Jay; Izaguirre, Eder; Kaplan, Jared; Katz, Emanuel; Kilic, Can; Kim, Hyung-Do; Kitano, Ryuichiro; Koay, Sue Ann; Ko, Pyungwon; Krohn, David; Kuflik, Eric; Lewis, Ian; Lisanti (Editor, Mariangela; Liu, Tao; Liu, Zhen; Lu, Ran; Luty, Markus; Meade, Patrick; Morrissey, David; Mrenna, Stephen; Nojiri, Mihoko; Okui, Takemichi; Padhi, Sanjay; Papucci, Michele; Park, Michael; Park, Myeonghun; Perelstein, Maxim; Peskin, Michael; Phalen, Daniel; Rehermann, Keith; Rentala, Vikram; Roy, Tuhin; Ruderman, Joshua T.; Sanz, Veronica; Schmaltz, Martin; Schnetzer, Stephen; Schuster (Editor, Philip; Schwaller, Pedro; Schwartz, Matthew D.; Schwartzman, Ariel; Shao, Jing; Shelton, Jessie; Shih, David; Shu, Jing; Silverstein, Daniel; Simmons, Elizabeth; Somalwar, Sunil; Spannowsky, Michael; Spethmann, Christian; Strassler, Matthew; Su, Shufang; Tait (Editor, Tim; Thomas, Brooks; Thomas, Scott; Toro (Editor, Natalia; Volansky, Tomer; Wacker (Editor, Jay; Waltenberger, Wolfgang; Yavin, Itay; Yu, Felix; Zhao, Yue; Zurek, Kathryn; LHC New Physics Working Group

    2012-10-01

    This document proposes a collection of simplified models relevant to the design of new-physics searches at the Large Hadron Collider (LHC) and the characterization of their results. Both ATLAS and CMS have already presented some results in terms of simplified models, and we encourage them to continue and expand this effort, which supplements both signature-based results and benchmark model interpretations. A simplified model is defined by an effective Lagrangian describing the interactions of a small number of new particles. Simplified models can equally well be described by a small number of masses and cross-sections. These parameters are directly related to collider physics observables, making simplified models a particularly effective framework for evaluating searches and a useful starting point for characterizing positive signals of new physics. This document serves as an official summary of the results from the ‘Topologies for Early LHC Searches’ workshop, held at SLAC in September of 2010, the purpose of which was to develop a set of representative models that can be used to cover all relevant phase space in experimental searches. Particular emphasis is placed on searches relevant for the first ˜50-500 pb-1 of data and those motivated by supersymmetric models. This note largely summarizes material posted at http://lhcnewphysics.org/, which includes simplified model definitions, Monte Carlo material, and supporting contacts within the theory community. We also comment on future developments that may be useful as more data is gathered and analyzed by the experiments.

  8. Model reduction in the physical coordinate system

    NASA Technical Reports Server (NTRS)

    Yae, K. Harold; Joeng, K. Y.

    1989-01-01

    In the dynamics modeling of a flexible structure, finite element analysis employs reduction techniques, such as Guyan's reduction, to remove some of the insignificant physical coordinates, thus producing a dynamics model that has smaller mass and stiffness matrices. But this reduction is limited in the sense that it removes certain degrees of freedom at a node points themselves in the model. From the standpoint of linear control design, the resultant model is still too large despite the reduction. Thus, some form of the model reduction is frequently used in control design by approximating a large dynamical system with a fewer number of state variables. However, a problem arises from the placement of sensors and actuators in the reduced model, because a model usually undergoes, before being reduced, some form of coordinate transformations that do not preserve the physical meanings of the states. To correct such a problem, a method is developed that expresses a reduced model in terms of a subset of the original states. The proposed method starts with a dynamic model that is originated and reduced in finite element analysis. Then the model is converted to the state space form, and reduced again by the internal balancing method. At this point, being in the balanced coordinate system, the states in the reduced model have no apparent resemblance to those of the original model. Through another coordinate transformation that is developed, however, this reduced model is expressed by a subset of the original states.

  9. A physical corrosion model for bioabsorbable metal stents.

    PubMed

    Grogan, J A; Leen, S B; McHugh, P E

    2014-05-01

    Absorbable metal stents (AMSs) are an emerging technology in the treatment of heart disease. Computational modelling of AMS performance will facilitate the development of this technology. In this study a physical corrosion model is developed for AMSs based on the finite element method and adaptive meshing. The model addresses a gap between currently available phenomenological corrosion models for AMSs and physical corrosion models that have been developed for more simple geometries than those of a stent. The model developed in this study captures the changing surface of a corroding three-dimensional AMS structure for the case of diffusion-controlled corrosion. Comparisons are made between model predictions and those of previously developed phenomenological corrosion models for AMSs in terms of predicted device geometry and mechanical performance during corrosion. Relationships between alloy solubility and diffusivity in the corrosion environment and device performance during corrosion are also investigated.

  10. Physical and stochastic models of earthquake clustering

    NASA Astrophysics Data System (ADS)

    Console, Rodolfo; Murru, Maura; Catalli, Flaminia

    2006-04-01

    The phenomenon of earthquake clustering, i.e., the increase of occurrence probability for seismic events close in space and time to other previous earthquakes, has been modeled both by statistical and physical processes. From a statistical viewpoint the so-called epidemic model (ETAS) introduced by Ogata in 1988 and its variations have become fairly well known in the seismological community. Tests on real seismicity and comparison with a plain time-independent Poissonian model through likelihood-based methods have reliably proved their validity. On the other hand, in the last decade many papers have been published on the so-called Coulomb stress change principle, based on the theory of elasticity, showing qualitatively that an increase of the Coulomb stress in a given area is usually associated with an increase of seismic activity. More specifically, the rate-and-state theory developed by Dieterich in the '90s has been able to give a physical justification to the phenomenon known as Omori law. According to this law, a mainshock is followed by a series of aftershocks whose frequency decreases in time as an inverse power law. In this study we give an outline of the above-mentioned stochastic and physical models, and build up an approach by which these models can be merged in a single algorithm and statistically tested. The application to the seismicity of Japan from 1970 to 2003 shows that the new model incorporating the physical concept of the rate-and-state theory performs not worse than the purely stochastic model with two free parameters only. The numerical results obtained in these applications are related to physical characters of the model as the stress change produced by an earthquake close to its edges and to the A and σ parameters of the rate-and-state constitutive law.

  11. Access Nets: Modeling Access to Physical Spaces

    NASA Astrophysics Data System (ADS)

    Frohardt, Robert; Chang, Bor-Yuh Evan; Sankaranarayanan, Sriram

    Electronic, software-managed mechanisms using, for example, radio-frequency identification (RFID) cards, enable great flexibility in specifying access control policies to physical spaces. For example, access rights may vary based on time of day or could differ in normal versus emergency situations. With such fine-grained control, understanding and reasoning about what a policy permits becomes surprisingly difficult requiring knowledge of permission levels, spatial layout, and time. In this paper, we present a formal modeling framework, called AccessNets, suitable for describing a combination of access permissions, physical spaces, and temporal constraints. Furthermore, we provide evidence that model checking techniques are effective in reasoning about physical access control policies. We describe our results from a tool that uses reachability analysis to validate security policies.

  12. Problem Solving: Physics Modeling-Based Interactive Engagement

    ERIC Educational Resources Information Center

    Ornek, Funda

    2009-01-01

    The purpose of this study was to investigate how modeling-based instruction combined with an interactive-engagement teaching approach promotes students' problem solving abilities. I focused on students in a calculus-based introductory physics course, based on the matter and interactions curriculum of Chabay & Sherwood (2002) at a large state…

  13. Ladder physics in the spin fermion model

    DOE PAGES

    Tsvelik, A. M.

    2017-05-01

    A link is established between the spin fermion (SF) model of the cuprates and the approach based on the analogy between the physics of doped Mott insulators in two dimensions and the physics of fermionic ladders. This enables one to use nonperturbative results derived for fermionic ladders to move beyond the large-N approximation in the SF model. Here, it is shown that the paramagnon exchange postulated in the SF model has exactly the right form to facilitate the emergence of the fully gapped d-Mott state in the region of the Brillouin zone at the hot spots of the Fermi surface.more » Hence, the SF model provides an adequate description of the pseudogap.« less

  14. Physical models of tissue in shear fields.

    PubMed

    Carstensen, Edwin L; Parker, Kevin J

    2014-04-01

    This review considers three general classes of physical as opposed to phenomenological models of the shear elasticity of tissues. The first is simple viscoelasticity. This model has a special role in elastography because it is the language in which experimental and clinical data are communicated. The second class of models involves acoustic relaxation, in which the medium contains inner time-dependent systems that are driven through the external bulk medium. Hysteresis, the phenomenon characterizing the third class of models, involves losses that are related to strain rather than time rate of change of strain. In contrast to the vast efforts given to tissue characterization through their bulk moduli over the last half-century, similar research using low-frequency shear data is in its infancy. Rather than a neat summary of existing facts, this essay is a framework for hypothesis generation-guessing what physical mechanisms give tissues their shear properties.

  15. Dilution physics modeling: Dissolution/precipitation chemistry

    SciTech Connect

    Onishi, Y.; Reid, H.C.; Trent, D.S.

    1995-09-01

    This report documents progress made to date on integrating dilution/precipitation chemistry and new physical models into the TEMPEST thermal-hydraulics computer code. Implementation of dissolution/precipitation chemistry models is necessary for predicting nonhomogeneous, time-dependent, physical/chemical behavior of tank wastes with and without a variety of possible engineered remediation and mitigation activities. Such behavior includes chemical reactions, gas retention, solids resuspension, solids dissolution and generation, solids settling/rising, and convective motion of physical and chemical species. Thus this model development is important from the standpoint of predicting the consequences of various engineered activities, such as mitigation by dilution, retrieval, or pretreatment, that can affect safe operations. The integration of a dissolution/precipitation chemistry module allows the various phase species concentrations to enter into the physical calculations that affect the TEMPEST hydrodynamic flow calculations. The yield strength model of non-Newtonian sludge correlates yield to a power function of solids concentration. Likewise, shear stress is concentration-dependent, and the dissolution/precipitation chemistry calculations develop the species concentration evolution that produces fluid flow resistance changes. Dilution of waste with pure water, molar concentrations of sodium hydroxide, and other chemical streams can be analyzed for the reactive species changes and hydrodynamic flow characteristics.

  16. Mental Models in Expert Physics Reasoning.

    ERIC Educational Resources Information Center

    Roschelle, Jeremy; Greeno, James G.

    Proposed is a relational framework for characterizing experienced physicists' representations of physics problem situations and the process of constructing these representations. A representation includes a coherent set of relations among: (1) a mental model of the objects in the situation, along with their relevant properties and relations; (2) a…

  17. Physical models for classroom teaching in hydrology

    NASA Astrophysics Data System (ADS)

    Rodhe, A.

    2012-09-01

    Hydrology teaching benefits from the fact that many important processes can be illustrated and explained with simple physical models. A set of mobile physical models has been developed and used during many years of lecturing at basic university level teaching in hydrology. One model, with which many phenomena can be demonstrated, consists of a 1.0-m-long plexiglass container containing an about 0.25-m-deep open sand aquifer through which water is circulated. The model can be used for showing the groundwater table and its influence on the water content in the unsaturated zone and for quantitative determination of hydraulic properties such as the storage coefficient and the saturated hydraulic conductivity. It is also well suited for discussions on the runoff process and the significance of recharge and discharge areas for groundwater. The flow paths of water and contaminant dispersion can be illustrated in tracer experiments using fluorescent or colour dye. This and a few other physical models, with suggested demonstrations and experiments, are described in this article. The finding from using models in classroom teaching is that it creates curiosity among the students, promotes discussions and most likely deepens the understanding of the basic processes.

  18. A thermodynamic model of physical gels

    NASA Astrophysics Data System (ADS)

    An, Yonghao; Solis, Francisco J.; Jiang, Hanqing

    2010-12-01

    Physical gels are characterized by dynamic cross-links that are constantly created and broken, changing its state between solid and liquid under influence of environmental factors. This restructuring ability of physical gels makes them an important class of materials with many applications, such as in drug delivery. In this article, we present a thermodynamic model for physical gels that considers both the elastic properties of the network and the transient nature of the cross-links. The cross-links' reformation is captured through a connectivity tensor M at the microscopic level. The macroscopic quantities, such as the volume fraction of the monomer ϕ, number of monomers per cross-link s, and the number of cross-links per volume q, are defined by statistic averaging. A mean-field energy functional for the gel is constructed based on these variables. The equilibrium equations and the stress are obtained at the current state. We study the static thermodynamic properties of physical gels predicted by the model. We discuss the problems of un-constrained swelling and stress driven phase transitions of physical gels and describe the conditions under which these phenomena arise as functions of the bond activation energy Ea, polymer/solvent interaction parameter χ, and external stress p.

  19. Service Learning In Physics: The Consultant Model

    NASA Astrophysics Data System (ADS)

    Guerra, David

    2005-04-01

    Each year thousands of students across the country and across the academic disciplines participate in service learning. Unfortunately, with no clear model for integrating community service into the physics curriculum, there are very few physics students engaged in service learning. To overcome this shortfall, a consultant based service-learning program has been developed and successfully implemented at Saint Anselm College (SAC). As consultants, students in upper level physics courses apply their problem solving skills in the service of others. Most recently, SAC students provided technical and managerial support to a group from Girl's Inc., a national empowerment program for girls in high-risk, underserved areas, who were participating in the national FIRST Lego League Robotics competition. In their role as consultants the SAC students provided technical information through brainstorming sessions and helped the girls stay on task with project management techniques, like milestone charting. This consultant model of service-learning, provides technical support to groups that may not have a great deal of resources and gives physics students a way to improve their interpersonal skills, test their technical expertise, and better define the marketable skill set they are developing through the physics curriculum.

  20. Multiscale physics-based modeling of friction

    NASA Astrophysics Data System (ADS)

    Eriten, Melih

    Frictional contacts between solids exist in nature and in a wide range of engineering applications. Friction causes energy loss, and it is the main source of wear and surface degradation which limits the lifetime of mechanical systems. Yet, friction is needed to walk, run, accelerate, slow down or stop moving systems. Whether desirable or not, friction is a very complex physical phenomenon. The behavior of systems with friction is nonlinear, and the physical mechanisms governing friction behavior span a wide range of spatial and temporal scales. A thorough study of friction should employ experimentalists and theoreticians in chemistry, materials science, tribology, mechanics, dynamics, and structural engineering. High spatial and temporal resolutions are required to capture and model essential physics of a frictional contact. However, such a detailed model is impractical in large-scale structural dynamics simulations; especially since frictional contacts can be numerous in a given application. Reduced-order models (ROMs) achieve broader applicability by compromising several aspects and accounting for the important physics. Hence, rather simple Coulomb friction is still the most ubiquitous model in the modeling and simulation literature. As an alternative, a reduced-order friction model built-up from micromechanics of surfaces is proposed in this work. Continuum-scale formulation of pre-sliding friction behavior is combined with material-strength-based friction coefficients to develop a physics-based friction model at asperity-scale. Then, the statistical summation technique is utilized to build a multiscale modeling framework. A novel joint fretting setup is designed for friction experiments in a practical setting, and the developed models are tested. Both asperity and rough surface friction models show good agreement with experimental data. The influences of materials, surface roughness and contact contamination on the friction are also studied. Finally, the

  1. Investigating Attitudes toward Physical Education: Validation across Two Instruments

    ERIC Educational Resources Information Center

    Donovan, Corinne Baron; Mercier, Kevin; Phillips, Sharon R.

    2015-01-01

    The Centers for Disease Control have suggested that physical education plays a role in promoting healthy lifestyles. Prior research suggests a link between attitudes toward physical education and physical activity outside school. The current study provides additional evidence of construct validity through a validation across two instruments…

  2. Investigating Attitudes toward Physical Education: Validation across Two Instruments

    ERIC Educational Resources Information Center

    Donovan, Corinne Baron; Mercier, Kevin; Phillips, Sharon R.

    2015-01-01

    The Centers for Disease Control have suggested that physical education plays a role in promoting healthy lifestyles. Prior research suggests a link between attitudes toward physical education and physical activity outside school. The current study provides additional evidence of construct validity through a validation across two instruments…

  3. Transforming teacher knowledge: Modeling instruction in physics

    NASA Astrophysics Data System (ADS)

    Cabot, Lloyd H.

    I show that the Modeling physics curriculum is readily accommodated by most teachers in favor of traditional didactic pedagogies. This is so, at least in part, because Modeling focuses on a small set of connected models embedded in a self-consistent theoretical framework and thus is closely congruent with human cognition in this context which is to generate mental models of physical phenomena as both predictive and explanatory devices. Whether a teacher fully implements the Modeling pedagogy depends on the depth of the teacher's commitment to inquiry-based instruction, specifically Modeling instruction, as a means of promoting student understanding of Newtonian mechanics. Moreover, this commitment trumps all other characteristics: teacher educational background, content coverage issues, student achievement data, district or state learning standards, and district or state student assessments. Indeed, distinctive differences exist in how Modeling teachers deliver their curricula and some teachers are measurably more effective than others in their delivery, but they all share an unshakable belief in the efficacy of inquiry-based, constructivist-oriented instruction. The Modeling Workshops' pedagogy, duration, and social interactions impacts teachers' self-identification as members of a professional community. Finally, I discuss the consequences my research may have for the Modeling Instruction program designers and for designers of professional development programs generally.

  4. Physics of Granular Materials: Investigations in Support of Astrobiology

    NASA Technical Reports Server (NTRS)

    Marshall, John R.

    2002-01-01

    This publication list is submitted as a summary of the work conducted under Cooperative Agreement 1120. The goal of the 1120 research was to study granular materials within a planetary, astrophysical, and astrobiological context. This involved research on the physical, mechanical and electrostatic properties of granular systems, as well as the examination of these materials with atomic force microscopy and x-ray analysis. Instruments for analyzing said materials in planetary environments were developed, including the MECA (Mars Environment Compatibility Assessment) experiment for the MSP '01 lander, the ECHOS/MATADOR experiment for the MSP '03 lander, an ISRU experiment for the '03 lander, and MiniLEAP technology. Flight experiments for microgravity (Space Station and Shuttle) have also been developed for the study of granular materials. As expressed in the publications, work on 1120 encompassed laboratory research, theoretical modeling, field experiments, and flight experiments: a series of successful new models were developed for understanding the behavior of triboelectrostatically charged granular masses, and 4 separate instruments were selected for space flight. No inventions or patents were generated by the research under this Agreement.

  5. Modelling Students' Construction of Energy Models in Physics.

    ERIC Educational Resources Information Center

    Devi, Roshni; And Others

    1996-01-01

    Examines students' construction of experimentation models for physics theories in energy storage, transformation, and transfers involving electricity and mechanics. Student problem solving dialogs and artificial intelligence modeling of these processes is analyzed. Construction of models established relations between elements with linear causal…

  6. Modelling Students' Construction of Energy Models in Physics.

    ERIC Educational Resources Information Center

    Devi, Roshni; And Others

    1996-01-01

    Examines students' construction of experimentation models for physics theories in energy storage, transformation, and transfers involving electricity and mechanics. Student problem solving dialogs and artificial intelligence modeling of these processes is analyzed. Construction of models established relations between elements with linear causal…

  7. Physics Beyond the Standard Model at Colliders

    NASA Astrophysics Data System (ADS)

    Matchev, Konstantin

    These lectures introduce the modern machinery used in searches and studies of new physics Beyond the Standard Model (BSM) at colliders. The first lecture provides an overview of the main simulation tools used in high energy physics, including automated parton-level calculators, general purpose event generators, detector simulators, etc. The second lecture is a brief introduction to low energy supersymmetry (SUSY) as a representative BSM paradigm. The third lecture discusses the main collider signatures of SUSY and methods for measuring the masses of new particles in events with missing energy.

  8. Modeling quantum physics with machine learning

    NASA Astrophysics Data System (ADS)

    Lopez-Bezanilla, Alejandro; Arsenault, Louis-Francois; Millis, Andrew; Littlewood, Peter; von Lilienfeld, Anatole

    2014-03-01

    Machine Learning (ML) is a systematic way of inferring new results from sparse information. It directly allows for the resolution of computationally expensive sets of equations by making sense of accumulated knowledge and it is therefore an attractive method for providing computationally inexpensive 'solvers' for some of the important systems of condensed matter physics. In this talk a non-linear regression statistical model is introduced to demonstrate the utility of ML methods in solving quantum physics related problem, and is applied to the calculation of electronic transport in 1D channels. DOE contract number DE-AC02-06CH11357.

  9. Physics Beyond the Standard Model: Supersymmetry

    SciTech Connect

    Nojiri, M.M.; Plehn, T.; Polesello, G.; Alexander, John M.; Allanach, B.C.; Barr, Alan J.; Benakli, K.; Boudjema, F.; Freitas, A.; Gwenlan, C.; Jager, S.; /CERN /LPSC, Grenoble

    2008-02-01

    This collection of studies on new physics at the LHC constitutes the report of the supersymmetry working group at the Workshop 'Physics at TeV Colliders', Les Houches, France, 2007. They cover the wide spectrum of phenomenology in the LHC era, from alternative models and signatures to the extraction of relevant observables, the study of the MSSM parameter space and finally to the interplay of LHC observations with additional data expected on a similar time scale. The special feature of this collection is that while not each of the studies is explicitly performed together by theoretical and experimental LHC physicists, all of them were inspired by and discussed in this particular environment.

  10. Modelling the Physical System of Belawan Estuary

    NASA Astrophysics Data System (ADS)

    Tarigan, A. P. M.; Swandana, D.; Isma, F.

    2017-03-01

    Belawan estuary represents one of the most complex and fascinating mixed environments of sea and land, where not only habitat of rich biodiversity but also international seaport infrastructure are at stake. It is therefore a matter of considerable importance to understand the physical system which characterizes the dynamics of the estuarine water. The purpose of this study is to model the changing water depths, tidal currents, salt, temperature and sediment concentration over a long stretch of Belawan estuary on an hourly basis. The first essential step is to define the bathymetry based on which other physical parameters are simulated. The study is accomplished by building working computer modules which simplify and model the systems complexities. It should be noted that model validation and improvement is the subject of the next study.

  11. Prototyping of cerebral vasculature physical models.

    PubMed

    Khan, Imad S; Kelly, Patrick D; Singer, Robert J

    2014-01-01

    Prototyping of cerebral vasculature models through stereolithographic methods have the ability to accurately depict the 3D structures of complicated aneurysms with high accuracy. We describe the method to manufacture such a model and review some of its uses in the context of treatment planning, research, and surgical training. We prospectively used the data from the rotational angiography of a 40-year-old female who presented with an unruptured right paraclinoid aneurysm. The 3D virtual model was then converted to a physical life-sized model. The model constructed was shown to be a very accurate depiction of the aneurysm and its associated vasculature. It was found to be useful, among other things, for surgical training and as a patient education tool. With improving and more widespread printing options, these models have the potential to become an important part of research and training modalities.

  12. Optical investigation of niobium properties: Electrical- and physical constants

    NASA Astrophysics Data System (ADS)

    Singh, Nageshwar; Deo, M. N.; Roy, S. B.

    2017-08-01

    In this paper, we report optical (reflectance) measurements and investigations of optical properties of electropolished (EP), buffered chemical polished (BCP), and as-received (AR) from vendor niobium (Nb) samples typically used for fabrication of superconducting radio frequency (SCRF) cavities. Optical conductivity (σ(0), approximated near zero frequency) of EP (σ(0) ∼ 9 × 103 Ω-1 cm-1) sample is one order of magnitude higher than that of BCP (σ(0) ∼ 7 × 102 Ω-1 cm-1) and AR (σ(0) ∼ 3 × 102 Ω-1 cm-1) niobium samples. Furthermore, physical constants of electropolished Nb-SCRF materials such as concentration of conduction electrons (∼ 1.8 × 1022 electrons/cm3), average velocity (∼ 5.9 × 107 cm/s) of the electrons on the Fermi surface, and mean free path (∼ 0.53 nm) were also found to be considerably higher than that of the BCP and the AR samples. The depth of electric field penetration (in low frequency region) in the electropolished Nb sample (∼ 80 nm) is appreciably lesser than the BCP (∼ 450 nm) and the AR (∼ 400 nm) samples.

  13. Quantitative investigation of ligament strains during physical tests for sacroiliac joint pain using finite element analysis.

    PubMed

    Kim, Yoon Hyuk; Yao, Zhidong; Kim, Kyungsoo; Park, Won Man

    2014-06-01

    It may be assumed that the stability is affected when some ligaments are injured or loosened, and this joint instability causes sacroiliac joint pain. Several physical examinations have been used to diagnose sacroiliac pain and to isolate the source of the pain. However, more quantitative and objective information may be necessary to identify unstable or injured ligaments during these tests due to the lack of understanding of the quantitative relationship between the physical tests and the biomechanical parameters that may be related to pains in the sacroiliac joint and the surrounding ligaments. In this study, a three-dimensional finite element model of the sacroiliac joint was developed and the biomechanical conditions for six typical physical tests such as the compression test, distraction test, sacral apex pressure test, thigh thrust test, Patrick's test, and Gaenslen's test were modelled. The sacroiliac joint contact pressure and ligament strain were investigated for each test. The values of contact pressure and the combination of most highly strained ligaments differed markedly among the tests. Therefore, these findings in combination with the physical tests would be helpful to identify the pain source and to understand the pain mechanism. Moreover, the technology provided in this study might be a useful tool to evaluate the physical tests, to improve the present test protocols, or to develop a new physical test protocol.

  14. Physical modeling of the composting ecosystem.

    PubMed

    Hogan, J A; Miller, F C; Finstein, M S

    1989-05-01

    A composting physical model with an experimental chamber with a working volume of 14 x 10 cm (0.5 ft) was designed to avoid exaggerated conductive heat loss resulting from, relative to field-scale piles, a disproportionately large outer surface-area-to-volume ratio. In the physical model, conductive flux (rate of heat flow through chamber surfaces) was made constant and slight through a combination of insulation and temperature control of the surrounding air. This control was based on the instantaneous conductive flux, as calculated from temperature differentials via a conductive heat flow model. An experiment was performed over a 10-day period in which control of the composting process was based on ventilative heat removal in reference to a microbially favorable temperature ceiling (temperature feedback). By using the conduction control system (surrounding air temperature controlled), 2.4% of the total heat evolved from the chamber was through conduction, whereas the remainder was through the ventilative mechanisms of the latent heat of vaporization and the sensible temperature increase of air. By comparison, with insulation alone (the conduction control system was not used) conduction accounted for 33.5% of the total heat evolved. This difference in conduction resulted in substantial behavioral differences with respect to the temperature of the composting matrix and the amount of water removed. By emphasizing the slight conduction system (2.4% of total heat flow) as being a better representative of field conditions, a comparison was made between composting system behavior in the laboratory physical model and field-scale piles described in earlier reports. Numerous behavioral patterns were qualitatively similar in the laboratory and field (e.g., temperature gradient, O(2) content, and water removal). It was concluded that field-scale composting system behavior can be simulated reasonably faithfully in the physical model.

  15. Electromagnetic Physics Models for Parallel Computing Architectures

    NASA Astrophysics Data System (ADS)

    Amadio, G.; Ananya, A.; Apostolakis, J.; Aurora, A.; Bandieramonte, M.; Bhattacharyya, A.; Bianchini, C.; Brun, R.; Canal, P.; Carminati, F.; Duhem, L.; Elvira, D.; Gheata, A.; Gheata, M.; Goulas, I.; Iope, R.; Jun, S. Y.; Lima, G.; Mohanty, A.; Nikitina, T.; Novak, M.; Pokorski, W.; Ribon, A.; Seghal, R.; Shadura, O.; Vallecorsa, S.; Wenzel, S.; Zhang, Y.

    2016-10-01

    The recent emergence of hardware architectures characterized by many-core or accelerated processors has opened new opportunities for concurrent programming models taking advantage of both SIMD and SIMT architectures. GeantV, a next generation detector simulation, has been designed to exploit both the vector capability of mainstream CPUs and multi-threading capabilities of coprocessors including NVidia GPUs and Intel Xeon Phi. The characteristics of these architectures are very different in terms of the vectorization depth and type of parallelization needed to achieve optimal performance. In this paper we describe implementation of electromagnetic physics models developed for parallel computing architectures as a part of the GeantV project. Results of preliminary performance evaluation and physics validation are presented as well.

  16. Electromagnetic physics models for parallel computing architectures

    DOE PAGES

    Amadio, G.; Ananya, A.; Apostolakis, J.; ...

    2016-11-21

    The recent emergence of hardware architectures characterized by many-core or accelerated processors has opened new opportunities for concurrent programming models taking advantage of both SIMD and SIMT architectures. GeantV, a next generation detector simulation, has been designed to exploit both the vector capability of mainstream CPUs and multi-threading capabilities of coprocessors including NVidia GPUs and Intel Xeon Phi. The characteristics of these architectures are very different in terms of the vectorization depth and type of parallelization needed to achieve optimal performance. In this paper we describe implementation of electromagnetic physics models developed for parallel computing architectures as a part ofmore » the GeantV project. Finally, the results of preliminary performance evaluation and physics validation are presented as well.« less

  17. Electromagnetic physics models for parallel computing architectures

    SciTech Connect

    Amadio, G.; Ananya, A.; Apostolakis, J.; Aurora, A.; Bandieramonte, M.; Bhattacharyya, A.; Bianchini, C.; Brun, R.; Canal, P.; Carminati, F.; Duhem, L.; Elvira, D.; Gheata, A.; Gheata, M.; Goulas, I.; Iope, R.; Jun, S. Y.; Lima, G.; Mohanty, A.; Nikitina, T.; Novak, M.; Pokorski, W.; Ribon, A.; Seghal, R.; Shadura, O.; Vallecorsa, S.; Wenzel, S.; Zhang, Y.

    2016-11-21

    The recent emergence of hardware architectures characterized by many-core or accelerated processors has opened new opportunities for concurrent programming models taking advantage of both SIMD and SIMT architectures. GeantV, a next generation detector simulation, has been designed to exploit both the vector capability of mainstream CPUs and multi-threading capabilities of coprocessors including NVidia GPUs and Intel Xeon Phi. The characteristics of these architectures are very different in terms of the vectorization depth and type of parallelization needed to achieve optimal performance. In this paper we describe implementation of electromagnetic physics models developed for parallel computing architectures as a part of the GeantV project. Finally, the results of preliminary performance evaluation and physics validation are presented as well.

  18. Recess Physical Activity Packs in Elementary Schools: A Qualitative Investigation

    ERIC Educational Resources Information Center

    Elliott, Steven; Combs, Sue; Boyce, Robert

    2011-01-01

    To supplement the present weekly allotment of 30 minutes of physical education, a school district in southeastern North Carolina identified recess time as part of the state mandated (HSP-S-000) 150 minutes of physical activity (PA) per week and have purchased fitness equipment (recess packs) for the children to use. Twelve participants were…

  19. Recess Physical Activity Packs in Elementary Schools: A Qualitative Investigation

    ERIC Educational Resources Information Center

    Elliott, Steven; Combs, Sue; Boyce, Robert

    2011-01-01

    To supplement the present weekly allotment of 30 minutes of physical education, a school district in southeastern North Carolina identified recess time as part of the state mandated (HSP-S-000) 150 minutes of physical activity (PA) per week and have purchased fitness equipment (recess packs) for the children to use. Twelve participants were…

  20. Statistical Physics of Pairwise Probability Models

    PubMed Central

    Roudi, Yasser; Aurell, Erik; Hertz, John A.

    2009-01-01

    Statistical models for describing the probability distribution over the states of biological systems are commonly used for dimensional reduction. Among these models, pairwise models are very attractive in part because they can be fit using a reasonable amount of data: knowledge of the mean values and correlations between pairs of elements in the system is sufficient. Not surprisingly, then, using pairwise models for studying neural data has been the focus of many studies in recent years. In this paper, we describe how tools from statistical physics can be employed for studying and using pairwise models. We build on our previous work on the subject and study the relation between different methods for fitting these models and evaluating their quality. In particular, using data from simulated cortical networks we study how the quality of various approximate methods for inferring the parameters in a pairwise model depends on the time bin chosen for binning the data. We also study the effect of the size of the time bin on the model quality itself, again using simulated data. We show that using finer time bins increases the quality of the pairwise model. We offer new ways of deriving the expressions reported in our previous work for assessing the quality of pairwise models. PMID:19949460

  1. Video Analysis and Modeling in Physics Education

    NASA Astrophysics Data System (ADS)

    Brown, Doug

    2008-03-01

    The Tracker video analysis program allows users to overlay simple dynamical models on a video clip. Video modeling offers advantages over both traditional video analysis and animation-only modeling. In traditional video analysis, for example, students measure ``g'' by tracking a dropped or tossed ball, constructing a position or velocity vs. time graph, and interpreting the graphs to obtain initial conditions and acceleration. In video modeling, by contrast, the students interactively construct theoretical force expressions and define initial conditions for a dynamical particle model that synchs with and draws itself on the video. The behavior of the model is thus compared directly with that of the real-world motion. Tracker uses the Open Source Physics code library so sophisticated models are possible. I will demonstrate and compare video modeling with video analysis and I will discuss the advantages of video modeling over animation-only modeling. The Tracker video analysis program is available at: http://www.cabrillo.edu/˜dbrown/tracker/.

  2. Generomak: Fusion physics, engineering and costing model

    SciTech Connect

    Delene, J.G.; Krakowski, R.A.; Sheffield, J.; Dory, R.A.

    1988-06-01

    A generic fusion physics, engineering and economics model (Generomak) was developed as a means of performing consistent analysis of the economic viability of alternative magnetic fusion reactors. The original Generomak model developed at Oak Ridge by Sheffield was expanded for the analyses of the Senior Committee on Environmental Safety and Economics of Magnetic Fusion Energy (ESECOM). This report describes the Generomak code as used by ESECOM. The input data used for each of the ten ESECOM fusion plants and the Generomak code output for each case is given. 14 refs., 3 figs., 17 tabs.

  3. Physical models of polarization mode dispersion

    SciTech Connect

    Menyuk, C.R.; Wai, P.K.A.

    1995-12-31

    The effect of randomly varying birefringence on light propagation in optical fibers is studied theoretically in the parameter regime that will be used for long-distance communications. In this regime, the birefringence is large and varies very rapidly in comparison to the nonlinear and dispersive scale lengths. We determine the polarization mode dispersion, and we show that physically realistic models yield the same result for polarization mode dispersion as earlier heuristic models that were introduced by Poole. We also prove an ergodic theorem.

  4. Physical Modelling of the Zodiacal Dust Cloud

    NASA Astrophysics Data System (ADS)

    Ozernoy, L. M.

    2001-01-01

    This review is based on an extensive work aimed at the physical modeling of the interplanetary dust (IPD) cloud, i.e. establishing a link between the observable characteristics of the zodiacal cloud and the dynamical and physical properties of the parent minor bodies of the Solar System, which has been done in collaboration with N. Gorkavyi, J. Mather, and T. Taidakova. We use a new computational approach proposed by the authors, which makes it possible to elaborate high-quality 3D models of the IPD cloud with the number of particle positions in each model as high as 1010-11. This approach enables us to simulate the distribution of the major sources of dust in the Solar System. In particular, they include 20-30 million cold comets gravitationally scattered by the four giant planets in cometary journey from the Kuiper belt inward in the Solar System. These comets are found to be distributed in the form of four `cometary belts' associated with the orbits of the giant planets. Our 3D physical model of the IPD cloud, which includes three dust components -- asteroidal, cometary, and kuiperoidal, explains three different kinds of data: (i) the distribution of sources of dust, both known and predicted to exist from computer simulations; (ii) zodiacal light distribution in the Solar System, which fits the COBE data with an average accuracy of 0.85%; and (iii) the experimental data of Pioneers and Voyagers dust detectors. Further improvements of our modeling and their importance for astronomy and cosmology are outlined.

  5. Physical property data on coarse anthracite waste. Report of investigations

    SciTech Connect

    Stewart, B.M.; Atkins, L.A.

    1983-07-01

    Since 1974, a large amount of data has been developed concerning the physical properties and stability characteristics of waste generated by the mining and preparation of bituminous coal. However, very little information has been developed on the properties and characteristics of anthracite waste. During this Bureau of Mines research project, coarse anthracite breaker refuse from five sites in eastern Pennsylvania was sampled and the physical properties, which indicate stability characteristics, were determined in the laboratory. Stability analyses were conducted on six theoretical anthracite waste embankments. These analyses show the effects on minimum safety factors of geometry, phreatic surface level, and physical properties.

  6. Beyond the Standard Model Physics with Lattice Simulations

    NASA Astrophysics Data System (ADS)

    Rinaldi, Enrico

    2016-03-01

    Lattice simulations of gauge theories are a powerful tool to investigate strongly interacting systems like Quantum ChromoDynamics (QCD). In recent years, the expertise gathered from lattice QCD studies has been used to explore new extensions of the Standard Model of particle physics that include strong dynamics. This change of gear in lattice field theories is related to the growing experimental search for new physics, from accelerator facilites like the Large Hadron Collider (LHC) to dark matter detectors like LUX or ADMX. In my presentation I will explore different plausible scenarios for physics beyond the standard model where strong dynamics play a dominant role and can be tackled by numerical lattice simulations. The importance of lattice field theories is highlighted in the context of dark matter searches and the search for new resonances at the LHC. Acknowledge the support of the DOE under Contract DE-AC52-07NA27344 (LLNL).

  7. Investigation of the Physics of Flocculation in Algal Systems

    NASA Astrophysics Data System (ADS)

    Pierce, Flint; Lechman, Jeremy; Hewson, John

    2012-02-01

    Algae biofuel production has gained a great deal of interest in recent years due to the high photosynthetic efficiency of various algae strains and the ability of stressed algae populations to produce large quantities of lipids within their cells. Separation of the algae from the background aqueous medium engenders large energetic costs for standard separation techniques including filtration, centrifugation, and dissolved air flotation since algae cells are small (microns to 10s of microns), have densities similar to the surrounding fluid, and normally occur at low volume fractions (1E-4 -> 1E-3). Flocculation is one possible route to reducing the cost of collecting the algae biomass, since large algae flocs can easily be removed from the aqueous environment through either differential settling or standard filtration. To this end, We model flocculating systems of algae cells using discrete particle dynamics techniques which incorporate a recently developed adhesive granular potential to govern the cell interactions. This potential is shown to reproduce morphological characteristics, kinetics, and size distributions that agree well with known results for flocculation in the diffusive regime (DLCA). We further investigate flocculation under steady shear and compare our results to both experiment and predictions from various orthokinetic models.

  8. An Investigation of the Physical Properties of Erupting Solar Prominences

    DTIC Science & Technology

    2010-11-30

    Solar physics Chromosphere Solar corona Solar magnetic fields Coronal mass ejections...polarimeter deployed at the ESF. It is mainly conceived to do spectro-polarimetry of the chromosphere (in particular prominences and filaments

  9. Investigations in γ-Ray Astrophysics and Astroparticle Physics

    SciTech Connect

    Krennrich, Frank

    2016-06-28

    This report describes the status of data analysis efforts, results and publications of research grant DE-SC0009917. The research is focused on TeV gamma-ray studies of astrophysical sources and related particle physics questions.

  10. Investigation of physical and chemical stability of ointment with herbals.

    PubMed

    Zdoryk, Oleksandr A; Khokhlova, Kateryna O; Georgiyants, Victoriya A; Vyshnevska, Liliia I

    2014-01-01

    The physical and chemical stability of a stock preparation ointment with active ingredients-herbal tinctures of calendula and arnica-for the treatment of hemorrhoids was studied. Evaluations for physical and chemical stability were performed initially and throughout the storage period. Physical stability of the ointment was assessed by means of visual observation in normal room light. Throughout the study period, the physical appearance of the ointment did not change. The chemical stability of the ointment was evaluated by means of a stability-indicating, thin-layer chromatography analytical technique. The shelf-life was found to be one month at 25 degrees C +/- 2 degrees C/60% RH and two months at 5 degrees C +/- 3 degrees C, when protected from light.

  11. Improving the physics models in the Space Weather Modeling Framework

    NASA Astrophysics Data System (ADS)

    Toth, G.; Fang, F.; Frazin, R. A.; Gombosi, T. I.; Ilie, R.; Liemohn, M. W.; Manchester, W. B.; Meng, X.; Pawlowski, D. J.; Ridley, A. J.; Sokolov, I.; van der Holst, B.; Vichare, G.; Yigit, E.; Yu, Y.; Buzulukova, N.; Fok, M. H.; Glocer, A.; Jordanova, V. K.; Welling, D. T.; Zaharia, S. G.

    2010-12-01

    The success of physics based space weather forecasting depends on several factors: we need sufficient amount and quality of timely observational data, we have to understand the physics of the Sun-Earth system well enough, we need sophisticated computational models, and the models have to run faster than real time on the available computational resources. This presentation will focus on a single ingredient, the recent improvements of the mathematical and numerical models in the Space Weather Modeling Framework. We have developed a new physics based CME initiation code using flux emergence from the convection zone solving the equations of radiative magnetohydrodynamics (MHD). Our new lower corona and solar corona models use electron heat conduction, Alfven wave heating, and boundary conditions based on solar tomography. We can obtain a physically consistent solar wind model from the surface of the Sun all the way to the L1 point without artificially changing the polytropic index. The global magnetosphere model can now solve the multi-ion MHD equations and take into account the oxygen outflow from the polar wind model. We have also added the options of solving for Hall MHD and anisotropic pressure. Several new inner magnetosphere models have been added to the framework: CRCM, HEIDI and RAM-SCB. These new models resolve the pitch angle distribution of the trapped particles. The upper atmosphere model GITM has been improved by including a self-consistent equatorial electrodynamics and the effects of solar flares. This presentation will very briefly describe the developments and highlight some results obtained with the improved and new models.

  12. Models in Physics, Models for Physics Learning, and Why the Distinction May Matter in the Case of Electric Circuits

    ERIC Educational Resources Information Center

    Hart, Christina

    2008-01-01

    Models are important both in the development of physics itself and in teaching physics. Historically, the consensus models of physics have come to embody particular ontological assumptions and epistemological commitments. Educators have generally assumed that the consensus models of physics, which have stood the test of time, will also work well…

  13. Models in Physics, Models for Physics Learning, and Why the Distinction May Matter in the Case of Electric Circuits

    ERIC Educational Resources Information Center

    Hart, Christina

    2008-01-01

    Models are important both in the development of physics itself and in teaching physics. Historically, the consensus models of physics have come to embody particular ontological assumptions and epistemological commitments. Educators have generally assumed that the consensus models of physics, which have stood the test of time, will also work well…

  14. A Physical Model of Electron Radiation Belts of Saturn

    NASA Astrophysics Data System (ADS)

    Lorenzato, L.; Sicard-Piet, A.; Bourdarie, S.

    2012-04-01

    Radiation belts causes irreversible damages on on-board instruments materials. That's why for two decades, ONERA proposes studies about radiation belts of magnetized planets. First, in the 90's, the development of a physical model, named Salammbô, carried out a model of the radiation belts of the Earth. Then, for few years, analysis of the magnetosphere of Jupiter and in-situ data (Pioneer, Voyager, Galileo) allow to build a physical model of the radiation belts of Jupiter. Enrolling on the Cassini age and thanks to all information collected, this study permits to adapt Salammbô jovian radiation belts model to the case of Saturn environment. Indeed, some physical processes present in the kronian magnetosphere are similar to those present in the magnetosphere of Jupiter (radial diffusion; interaction of energetic electrons with rings, moons, atmosphere; synchrotron emission). However, some physical processes have to be added to the kronian model (compared to the jovian model) because of the particularity of the magnetosphere of Saturn: interaction of energetic electrons with neutral particles from Enceladus, and wave-particle interaction. This last physical process has been studied in details with the analysis of CASSINI/RPWS (Radio and Plasma Waves Science) data. The major importance of the wave particles interaction is now well known in the case of the radiation belts of the Earth but it is important to investigate on its role in the case of Saturn. So, importance of each physical process has been studied and analysis of Cassini MIMI-LEMMS and CAPS data allows to build a model boundary condition (at L = 6). Finally, results of this study lead to a kronian electrons radiation belts model including radial diffusion, interactions of energetic electrons with rings, moons and neutrals particles and wave-particle interaction (interactions of electrons with atmosphere particles and synchrotron emission are too weak to be taken into account in this model). Then, to

  15. Future high precision experiments and new physics beyond Standard Model

    SciTech Connect

    Luo, Mingxing

    1993-04-01

    High precision (< 1%) electroweak experiments that have been done or are likely to be done in this decade are examined on the basis of Standard Model (SM) predictions of fourteen weak neutral current observables and fifteen W and Z properties to the one-loop level, the implications of the corresponding experimental measurements to various types of possible new physics that enter at the tree or loop level were investigated. Certain experiments appear to have special promise as probes of the new physics considered here.

  16. Future high precision experiments and new physics beyond Standard Model

    SciTech Connect

    Luo, Mingxing.

    1993-01-01

    High precision (< 1%) electroweak experiments that have been done or are likely to be done in this decade are examined on the basis of Standard Model (SM) predictions of fourteen weak neutral current observables and fifteen W and Z properties to the one-loop level, the implications of the corresponding experimental measurements to various types of possible new physics that enter at the tree or loop level were investigated. Certain experiments appear to have special promise as probes of the new physics considered here.

  17. Beyond the standard model of particle physics.

    PubMed

    Virdee, T S

    2016-08-28

    The Large Hadron Collider (LHC) at CERN and its experiments were conceived to tackle open questions in particle physics. The mechanism of the generation of mass of fundamental particles has been elucidated with the discovery of the Higgs boson. It is clear that the standard model is not the final theory. The open questions still awaiting clues or answers, from the LHC and other experiments, include: What is the composition of dark matter and of dark energy? Why is there more matter than anti-matter? Are there more space dimensions than the familiar three? What is the path to the unification of all the fundamental forces? This talk will discuss the status of, and prospects for, the search for new particles, symmetries and forces in order to address the open questions.This article is part of the themed issue 'Unifying physics and technology in light of Maxwell's equations'.

  18. Reconciling Physical and Seismic Reference Mantle Models: Geographical Sampling Biases

    NASA Astrophysics Data System (ADS)

    Lau, H. C.; Goes, S. D.; Davies, R.

    2012-12-01

    Earth's internal structure is, to a very good first approximation, spherically symmetric. Seismic imaging of lateral anomalies, which are the expression of mantle dynamics, relies on a well-constrained 1-D reference structure. Similarly, interpretation of 3-D seismic structure relies on understanding the physical nature of the 1-D reference. However, plausible physical models of average mantle structure, once converted to seismic velocity, fail to explain the observed 1-D reference velocities. In particular, relative to seismic reference models, the average physical structure for a thermally and chemically well-mixed (i.e., pyrolitic) mantle is: (i) consistently slower in the upper mantle; and (ii) has a higher velocity gradient in the lower mantle. Here, we investigate whether or not geographically biased sampling by the seismic waves used to construct seismic reference models, plays a role in this mismatch. This is done by calculating P-wave travel times through an Earth-like synthetic mantle structure and comparing sampled average synthetic travel times with model average travel times. Our synthetic structure is generated from a global spherical mantle circulation model, in which the geographic distribution of heterogeneity is constrained by 300 million years of plate motion history. Results indicate that geographical biasing is of the same magnitude as the mismatch between our physical model and a seismic reference model. We find that preferential propagation of rays along subduction zones in the upper mantle, together with more uniform sampling by rays in the lower mantle, would lead to a recovered reference model that shows: (i) increased upper mantle velocities; and (ii) a decreased velocity gradient in the lower mantle, when compared to the actual model reference. These tests with P travel times imply that a thermally and chemically well-mixed mantle may actually be consistent with seismic reference mantle models, but further tests with other wave types

  19. Dissecting new physics models through kinematic edges

    NASA Astrophysics Data System (ADS)

    Iyer, Abhishek M.; Maitra, Ushoshi

    2017-02-01

    Kinematic edges in the invariant mass distributions of different final state particles are typically a signal of new physics. In this work we propose a scenario wherein these edges could be utilized in discriminating between different classes of models. To this effect, we consider the resonant production of a heavy Higgs like resonance (H1) as a case study. Such states are a characteristic feature of many new physics scenarios beyond the standard model (SM). In the event of a discovery, it is essential to identify the true nature of the underlying theory. In this work we propose a channel, H1→t2t , where t2 is a vectorlike gauge singlet top-partner that decays into W b , Z t , h t . Invariant mass distributions constructed out of these final states are characterized by the presence of kinematic edges, which are unique to the topology under consideration. Further, since all the final state particles are SM states, the position in the edges of these invariant mass distributions can be used to exclusively determine the masses of the resonances. Observation of these features are meant to serve as a trigger, thereby mandating a more detailed analysis in a particular direction of parameter space. The absence of these edge like features, in the specific invariant mass distributions considered here, in minimal versions of supersymmetric models (MSSM) also serves as a harbinger of such non-MSSM-like scenarios.

  20. Physical model for membrane protrusions during spreading

    PubMed Central

    Chamaraux, François; Ali, Olivier; Keller, Sébastien; Bruckert, Franz; Fourcade, Bertrand

    2008-01-01

    During cell spreading onto a substrate, the kinetics of the contact area is an observable quantity. This paper is concerned with a physical approach to model this process in the case of ameboid motility where the membrane detaches itself from the underlying cytoskeleton at the leading edge. The physical model we propose is based on previous reports which point out that membrane tension regulates cell spreading. Using a phenomenological feedback loop to mimic stress dependent biochemistry, we show that the actin polymerisation rate can be coupled to the stress which builds up at the margin of the contact area between the cell and the substrate. In the limit of small variation of membrane tension, we show that the actin polymerisation rate can be written in closed form. Our analysis defines characteristic lengths which depend on elastic properties of the membrane-cytoskeleton complex, such as the membrane-cytoskeleton interaction, and on molecular parameters, such as the rate of actin polymerisation. We discuss our model in the case of axi-symmetric and non axi-symmetric spreading and we compute the characteristic time scales as a function of fundamental elastic constants such as the strength of membrane-cytoskeleton adherence. PMID:18824791

  1. Investigating Students' Reflective Thinking in the Introductory Physics Course

    NASA Astrophysics Data System (ADS)

    Boudreaux, Andrew

    2010-10-01

    Over the past 30 years, physics education research has guided the development of instructional strategies that can significantly enhance students' functional understanding of concepts in introductory physics. Recently, attention has shifted to instructional goals that, while widely shared by teachers of physics, are often more implicit than explicit in our courses. These goals involve the expectations and attitudes that students have about what it means to learn and understand physics, together with the behaviors and actions students think they should engage in to accomplish this learning. Research has shown that these ``hidden'' elements of the curriculum are remarkably resistant to instruction. In fact, traditional physics courses tend to produce movement away from expert-like behaviors. At Western Washington University, we are exploring ways of promoting metacognition, an aspect of the hidden curriculum that involves the conscious monitoring of one's own thinking and learning. We have found that making this reflective thinking an explicit part of the course may not be enough: adequate framing and scaffolding may be necessary for students to meaningfully engage in metacognition. We have thus taken the basic approach of developing metacognition, like conceptual understanding, through guided inquiry. During our teaching experiments, we have collected written and video data, with twin goals of guiding iterative modifications to the instruction as well as contributing to the knowledge base about student metacognition in introductory physics. This talk will provide examples of metacognition activities from course assignments and labs, and will present written data to assess the effectiveness of instruction and to illustrate specific modes of students' reflective thinking.

  2. Approximate input physics for stellar modelling

    NASA Astrophysics Data System (ADS)

    Pols, Onno R.; Tout, Christopher A.; Eggleton, Peter P.; Han, Zhanwen

    1995-06-01

    We present a simple and efficient, yet reasonably accurate, equation of state, which at the moderately low temperatures and high densities found in the interiors of stars less massive than the Sun is substantially more accurate than its predecessor by Eggleton, Faulkner & Flannery. Along with the most recently available values in tabular form of opacities, neutrino loss rates, and nuclear reaction rates for a selection of the most important reactions, this provides a convenient package of input physics for stellar modelling. We briefly discuss a few results obtained with the updated stellar evolution code.

  3. Physical model studies of water column separation

    NASA Astrophysics Data System (ADS)

    Autrique, R.; Rodal, E.; Sánchez, A.; Carmona, L.

    2012-11-01

    Results of physical model studies of water column separation following an upstream valve closure in a horizontal pipe are presented, using three dimensionless parameters: the magnitude of the transient, M, or the ratio between the Joukowsky pressure and the initial absolute head; ΔHr, or the ratio between the maximum overpressure and the Joukowsky pressure, and tcr, the duration of the vapor cavity relative to the pipeline period. Conclusions are derived, aiming to a better understanding of water column separation extreme pressures and to the establishment of useful preliminary design guidelines.

  4. Investigating Student Ownership of Projects in Upper-Division Physics Laboratory Courses

    NASA Astrophysics Data System (ADS)

    Stanley, Jacob

    In undergraduate research experiences, student development of an identity as a scientist is coupled to their sense of ownership of their research projects. As a first step towards studying similar connections in physics laboratory courses, we investigate student ownership of projects in a lasers-based upper-division course. Students spent the final seven weeks of the semester working in groups on final projects of their choosing. Using data from the Project Ownership Survey and weekly student reflections, we investigate student ownership as it relates to students' personal agency, self-efficacy, peer interactions, and complex affective responses to challenges and successes. We present evidence of students' project ownership in an upper-division physics lab. Additionally, we propose a model for student development of ownership through cycles of frustration and excitement as students progress on their projects. This work was supported by NSF Grant Nos. DUE-1323101 and DUE-1334170.

  5. Physical modeling synthesis of recorder sound

    NASA Astrophysics Data System (ADS)

    Shiraiwa, Hiroko; Kishi, Kenshi; Nakamura, Isao

    2003-04-01

    A time-domain simulation of the soprano baroque recorder based on the digital waveguide model (DWM) and an air reed model is introduced. The air reed model is developed upon the negative acoustic displacement model (NADM), which was proposed for the organ flue-pipe simulation [Adachi, Proc. of ISMA 1997, pp. 251-260], based on the semiempirical model by Fletcher [Fletcher and Rossing, The Physics of Musical Instruments, 2nd ed. (Springer, Berlin, 2000)]. Two models are proposed to couple DWM and NADM. The jet amplification coefficient is remodeled for the application of NADM for the recorder, regarding the recent experimental reports [Yoshikawa and Arimoto, Proc. of ISMA 2001, pp. 309-312]. The simulation results are presented in terms of the mode transient characteristics and the spectral characteristics of the synthesized sounds. They indicate that the NADM is not sufficient to describe the realistic mode transient of the recorder, while the synthesized sounds maintained almost resemble timbre to the recorder sounds.

  6. The physical sacrifice of thinking: Investigating the relationship between thinking and physical activity in everyday life.

    PubMed

    McElroy, Todd; Dickinson, David L; Stroh, Nathan; Dickinson, Christopher A

    2016-08-01

    Physical activity level is an important contributor to overall human health and obesity. Research has shown that humans possess a number of traits that influence their physical activity level including social cognition. We examined whether the trait of "need for cognition" was associated with daily physical activity levels. We recruited individuals who were high or low in need for cognition and measured their physical activity level in 30-second epochs over a 1-week period. The overall findings showed that low-need-for-cognition individuals were more physically active, but this difference was most pronounced during the 5-day work week and lessened during the weekend.

  7. Reappraising the Relationships between Physics Students' Mental Models and Predictions: An Example of Heat Convection

    ERIC Educational Resources Information Center

    Chiou, Guo-Li

    2013-01-01

    Although prediction is claimed to be a prime function of mental models, to what extent students can run their mental models to make predictions of physical phenomena remains uncertain. The purpose of this study, therefore, was first to investigate 30 physics students' mental models of heat convection, and then to examine the relationship between…

  8. Reappraising the Relationships between Physics Students' Mental Models and Predictions: An Example of Heat Convection

    ERIC Educational Resources Information Center

    Chiou, Guo-Li

    2013-01-01

    Although prediction is claimed to be a prime function of mental models, to what extent students can run their mental models to make predictions of physical phenomena remains uncertain. The purpose of this study, therefore, was first to investigate 30 physics students' mental models of heat convection, and then to examine the relationship between…

  9. The Effect of Physical Attractiveness of Models on Advertising Effectiveness for Male and Female Adolescents

    ERIC Educational Resources Information Center

    Tsai, Chia-Ching; Chang, Chih-Hsiang

    2007-01-01

    This study investigates the effect of advertising with physically attractive models on male and female adolescents. The findings suggest that highly attractive models are less effective than those who are normally attractive. Implications of social comparison are discussed.

  10. The effect of physical attractiveness of models on advertising effectiveness for male and female adolescents.

    PubMed

    Tsai, Chia-Ching; Chang, Chih-Hsiang

    2007-01-01

    This study investigates the effect of advertising with physically attractive models on male and female adolescents. The findings suggest that highly attractive models are less effective than those who are normally attractive. Implications of social comparison are discussed.

  11. The Effect of Physical Attractiveness of Models on Advertising Effectiveness for Male and Female Adolescents

    ERIC Educational Resources Information Center

    Tsai, Chia-Ching; Chang, Chih-Hsiang

    2007-01-01

    This study investigates the effect of advertising with physically attractive models on male and female adolescents. The findings suggest that highly attractive models are less effective than those who are normally attractive. Implications of social comparison are discussed.

  12. An Investigation of Physics Undergraduates' Attitudes towards Mathematics

    ERIC Educational Resources Information Center

    Symonds, Ria; Lawson, Duncan; Robinson, Carol

    2010-01-01

    In recent years, the failure rate on first-year mathematics modules on Physics courses at Loughborough University has given cause for concern. It was feared that failure in the first year would result in students performing poorly in future mathematics modules. Hence, a proactive support system was introduced for the mathematically less…

  13. Emotional Arousal of Beginning Physics Teachers during Extended Experimental Investigations

    ERIC Educational Resources Information Center

    Ritchie, Stephen M.; Tobin, Kenneth; Sandhu, Maryam; Sandhu, Satwant; Henderson, Senka; Roth, Wolff-Michael

    2013-01-01

    Teachers often have difficulty implementing inquiry-based activities, leading to the arousal of negative emotions. In this multicase study of beginning physics teachers in Australia, we were interested in the extent to which their expectations were realized and how their classroom experiences while implementing extended experimental investigations…

  14. Toward understanding writing to learn in physics: Investigating student writing

    NASA Astrophysics Data System (ADS)

    Demaree, Dedra

    It is received wisdom that writing in a discipline helps students learn the discipline, and millions of dollars have been committed at many universities to supporting such writing. We show that evidence for effectiveness is anecdotal, and that little data-based material informs these prejudices. This thesis begins the process of scientific study of writing in the discipline, in specific, in physics, and creates means to judge whether such writing is effective. The studies culminating in this thesis are an aggressive start to addressing these complex questions. Writing is often promoted as an activity that, when put into classrooms in specific disciplines, not only helps students learn to write in the methods of that discipline but also helps students learn content knowledge. Students at the Ohio State University are being asked to write more in introductory courses, and the Engineering schools want their students to have more writing skills for the job market. Combined with the desire of many educators to have students be able to explain the course content knowledge clearly, it would seem that writing activities would be important and useful in physics courses. However, the question of whether writing helps learning or whether students learn writing within a non-English classroom helps learning in the discipline are open to debate, and data are needed before such claims can be made. This thesis presents several studies aimed at understanding the correlation of writing and content, and tracking and characterizing student writing behaviors to see how they are impacted by writing in physics courses. It consists of four parts: summer and autumn 2005 focus on writing in introductory physics labs with and without explicit instruction, while winter and spring 2006 focus on tracking and analyzing student writing and revising behavior in Physics by Inquiry (PbI). With these related projects, we establish three main results. First, there is a need for quantitative studies of

  15. Systems and models with anticipation in physics and its applications

    NASA Astrophysics Data System (ADS)

    Makarenko, A.

    2012-11-01

    Investigations of recent physics processes and real applications of models require the new more and more improved models which should involved new properties. One of such properties is anticipation (that is taking into accounting some advanced effects).It is considered the special kind of advanced systems - namely a strong anticipatory systems introduced by D. Dubois. Some definitions, examples and peculiarities of solutions are described. The main feature is presumable multivaluedness of the solutions. Presumable physical examples of such systems are proposed: self-organization problems; dynamical chaos; synchronization; advanced potentials; structures in micro-, meso- and macro- levels; cellular automata; computing; neural network theory. Also some applications for modeling social, economical, technical and natural systems are described.

  16. Evaluating performances of simplified physically based landslide susceptibility models.

    NASA Astrophysics Data System (ADS)

    Capparelli, Giovanna; Formetta, Giuseppe; Versace, Pasquale

    2015-04-01

    Rainfall induced shallow landslides cause significant damages involving loss of life and properties. Prediction of shallow landslides susceptible locations is a complex task that involves many disciplines: hydrology, geotechnical science, geomorphology, and statistics. Usually to accomplish this task two main approaches are used: statistical or physically based model. This paper presents a package of GIS based models for landslide susceptibility analysis. It was integrated in the NewAge-JGrass hydrological model using the Object Modeling System (OMS) modeling framework. The package includes three simplified physically based models for landslides susceptibility analysis (M1, M2, and M3) and a component for models verifications. It computes eight goodness of fit indices (GOF) by comparing pixel-by-pixel model results and measurements data. Moreover, the package integration in NewAge-JGrass allows the use of other components such as geographic information system tools to manage inputs-output processes, and automatic calibration algorithms to estimate model parameters. The system offers the possibility to investigate and fairly compare the quality and the robustness of models and models parameters, according a procedure that includes: i) model parameters estimation by optimizing each of the GOF index separately, ii) models evaluation in the ROC plane by using each of the optimal parameter set, and iii) GOF robustness evaluation by assessing their sensitivity to the input parameter variation. This procedure was repeated for all three models. The system was applied for a case study in Calabria (Italy) along the Salerno-Reggio Calabria highway, between Cosenza and Altilia municipality. The analysis provided that among all the optimized indices and all the three models, Average Index (AI) optimization coupled with model M3 is the best modeling solution for our test case. This research was funded by PON Project No. 01_01503 "Integrated Systems for Hydrogeological Risk

  17. Detailed Physical Trough Model for NREL's Solar Advisor Model: Preprint

    SciTech Connect

    Wagner, M. J.; Blair, N.; Dobos, A.

    2010-10-01

    Solar Advisor Model (SAM) is a free software package made available by the National Renewable Energy Laboratory (NREL), Sandia National Laboratory, and the US Department of Energy. SAM contains hourly system performance and economic models for concentrating solar power (CSP) systems, photovoltaic, solar hot-water, and generic fuel-use technologies. Versions of SAM prior to 2010 included only the parabolic trough model based on Excelergy. This model uses top-level empirical performance curves to characterize plant behavior, and thus is limited in predictive capability for new technologies or component configurations. To address this and other functionality challenges, a new trough model; derived from physical first principles was commissioned to supplement the Excelergy-based empirical model. This new 'physical model' approaches the task of characterizing the performance of the whole parabolic trough plant by replacing empirical curve-fit relationships with more detailed calculations where practical. The resulting model matches the annual performance of the SAM empirical model (which has been previously verified with plant data) while maintaining run-times compatible with parametric analysis, adding additional flexibility in modeled system configurations, and providing more detailed performance calculations in the solar field, power block, piping, and storage subsystems.

  18. Physics model for wringing of wet cloth

    NASA Astrophysics Data System (ADS)

    Dany Rahmayanti, Handika; Utami, Fisca Dian; Abdullah, Mikrajuddin

    2016-11-01

    One activity that has been performed by human beings for a long time is washing clothes. Before the invention of the washing machine, clothes were washed by hand and then wrung before drying in the open air. When observed carefully, the wringing of cloth presents some interesting phenomena. However, there are no reports on the physical modelling of this very old activity. This paper reports a simple model to explain the discharge of water from clothes when squeezed. A simple tool was also designed to retrieve data to confirm the theory. We found that the theoretical predictions accurately explained the experimental results. The experiments were conducted on two types of cloth: towels and batik cloth. We also obtained a universal curve to which all the data converged.

  19. High precision modeling for fundamental physics experiments

    NASA Astrophysics Data System (ADS)

    Rievers, Benny; Nesemann, Leo; Costea, Adrian; Andres, Michael; Stephan, Ernst P.; Laemmerzahl, Claus

    With growing experimental accuracies and high precision requirements for fundamental physics space missions the needs for accurate numerical modeling techniques are increasing. Motivated by the challenge of length stability in cavities and optical resonators we propose the develop-ment of a high precision modeling tool for the simulation of thermomechanical effects up to a numerical precision of 10-20 . Exemplary calculations for simplified test cases demonstrate the general feasibility of high precision calculations and point out the high complexity of the task. A tool for high precision analysis of complex geometries will have to use new data types, advanced FE solver routines and implement new methods for the evaluation of numerical precision.

  20. Semi-Empirical Modeling of SLD Physics

    NASA Technical Reports Server (NTRS)

    Wright, William B.; Potapczuk, Mark G.

    2004-01-01

    The effects of supercooled large droplets (SLD) in icing have been an area of much interest in recent years. As part of this effort, the assumptions used for ice accretion software have been reviewed. A literature search was performed to determine advances from other areas of research that could be readily incorporated. Experimental data in the SLD regime was also analyzed. A semi-empirical computational model is presented which incorporates first order physical effects of large droplet phenomena into icing software. This model has been added to the LEWICE software. Comparisons are then made to SLD experimental data that has been collected to date. Results will be presented for the comparison of water collection efficiency, ice shape and ice mass.

  1. Tutorial: Physics and modeling of Hall thrusters

    NASA Astrophysics Data System (ADS)

    Boeuf, Jean-Pierre

    2017-01-01

    Hall thrusters are very efficient and competitive electric propulsion devices for satellites and are currently in use in a number of telecommunications and government spacecraft. Their power spans from 100 W to 20 kW, with thrust between a few mN and 1 N and specific impulse values between 1000 and 3000 s. The basic idea of Hall thrusters consists in generating a large local electric field in a plasma by using a transverse magnetic field to reduce the electron conductivity. This electric field can extract positive ions from the plasma and accelerate them to high velocity without extracting grids, providing the thrust. These principles are simple in appearance but the physics of Hall thrusters is very intricate and non-linear because of the complex electron transport across the magnetic field and its coupling with the electric field and the neutral atom density. This paper describes the basic physics of Hall thrusters and gives a (non-exhaustive) summary of the research efforts that have been devoted to the modelling and understanding of these devices in the last 20 years. Although the predictive capabilities of the models are still not sufficient for a full computer aided design of Hall thrusters, significant progress has been made in the qualitative and quantitative understanding of these devices.

  2. Physics-based models of the plasmasphere

    SciTech Connect

    Jordanova, Vania K; Pierrard, Vivane; Goldstein, Jerry; Andr'e, Nicolas; Lemaire, Joseph F; Liemohn, Mike W; Matsui, H

    2008-01-01

    We describe recent progress in physics-based models of the plasmasphere using the Auid and the kinetic approaches. Global modeling of the dynamics and inAuence of the plasmasphere is presented. Results from global plasmasphere simulations are used to understand and quantify (i) the electric potential pattern and evolution during geomagnetic storms, and (ii) the inAuence of the plasmasphere on the excitation of electromagnetic ion cyclotron (ElvIIC) waves a.nd precipitation of energetic ions in the inner magnetosphere. The interactions of the plasmasphere with the ionosphere a.nd the other regions of the magnetosphere are pointed out. We show the results of simulations for the formation of the plasmapause and discuss the inAuence of plasmaspheric wind and of ultra low frequency (ULF) waves for transport of plasmaspheric material. Theoretical formulations used to model the electric field and plasma distribution in the plasmasphere are given. Model predictions are compared to recent CLUSTER and MAGE observations, but also to results of earlier models and satellite observations.

  3. 3-D physical models of amitosis (cytokinesis).

    PubMed

    Cheng, Kang; Zou, Changhua

    2005-01-01

    Based on Newton's laws, extended Coulomb's law and published biological data, we develop our 3-D physical models of natural and normal amitosis (cytokinesis), for prokaryotes (bacterial cells) in M phase. We propose following hypotheses: Chromosome rings exclusion: No normally and naturally replicated chromosome rings (RCR) can occupy the same prokaryote, a bacterial cell. The RCR produce spontaneous and strong electromagnetic fields (EMF), that can be alternated environmentally, in protoplasm and cortex. The EMF is approximately a repulsive quasi-static electric (slowly variant and mostly electric) field (EF). The EF forces between the RCR are strong enough, and orderly accumulate contractile proteins that divide the procaryotes in the cell cortex of division plane or directly split the cell compartment envelope longitudinally. The radial component of the EF forces could also make furrows or cleavages of procaryotes. The EF distribution controls the protoplasm partition and completes the amitosis (cytokinesis). After the cytokinesis, the spontaneous and strong EF disappear because the net charge accumulation becomes weak, in the protoplasm. The exclusion is because the two sets of informative objects (RCR) have identical DNA codes information and they are electro magnetically identical, therefore they repulse from each other. We also compare divisions among eukaryotes, prokaryotes, mitochondria and chloroplasts and propose our hypothesis: The principles of our models are applied to divisions of mitochondria and chloroplasts of eucaryotes too because these division mechanisms are closer than others in a view of physics. Though we develop our model using 1 division plane (i.e., 1 cell is divided into 2 cells) as an example, the principle of our model is applied to the cases with multiple division planes (i.e., 1 cell is divided into multiple cells) too.

  4. Propulsion Physics Using the Chameleon Density Model

    NASA Technical Reports Server (NTRS)

    Robertson, Glen A.

    2011-01-01

    To grow as a space faring race, future spaceflight systems will require a new theory of propulsion. Specifically one that does not require mass ejection without limiting the high thrust necessary to accelerate within or beyond our solar system and return within a normal work period or lifetime. The Chameleon Density Model (CDM) is one such model that could provide new paths in propulsion toward this end. The CDM is based on Chameleon Cosmology a dark matter theory; introduced by Khrouy and Weltman in 2004. Chameleon as it is hidden within known physics, where the Chameleon field represents a scalar field within and about an object; even in the vacuum. The CDM relates to density changes in the Chameleon field, where the density changes are related to matter accelerations within and about an object. These density changes in turn change how an object couples to its environment. Whereby, thrust is achieved by causing a differential in the environmental coupling about an object. As a demonstration to show that the CDM fits within known propulsion physics, this paper uses the model to estimate the thrust from a solid rocket motor. Under the CDM, a solid rocket constitutes a two body system, i.e., the changing density of the rocket and the changing density in the nozzle arising from the accelerated mass. Whereby, the interactions between these systems cause a differential coupling to the local gravity environment of the earth. It is shown that the resulting differential in coupling produces a calculated value for the thrust near equivalent to the conventional thrust model used in Sutton and Ross, Rocket Propulsion Elements. Even though imbedded in the equations are the Universe energy scale factor, the reduced Planck mass and the Planck length, which relates the large Universe scale to the subatomic scale.

  5. Exploring New Physics Beyond the Standard Model: Final Technical Report

    SciTech Connect

    Wang, Liantao

    2016-10-17

    This grant in 2015 to 2016 was for support in the area of theoretical High Energy Physics. The research supported focused mainly on the energy frontier, but it also has connections to both the cosmic and intensity frontiers. Lian-Tao Wang (PI) focused mainly on signal of new physics at colliders. The year 2015 - 2016, covered by this grant, has been an exciting period of digesting the influx of LHC data, understanding its meaning, and using it to refine strategies for deeper exploration. The PI proposed new methods of searching for new physics at the LHC, such as for the compressed stops. He also investigated in detail the signal of composite Higgs models, focusing on spin-1 composite resonances in the di-boson channel. He has also considered di-photon as a probe for such models. He has also made contributions in formulating search strategies of dark matter at the LHC, resulting in two documents with recommendations. The PI has also been active in studying the physics potential of future colliders, including Higgs factories and 100 TeV pp colliders. He has given comprehensive overview of the physics potential of the high energy proton collider, and outline its luminosity targets. He has also studied the use of lepton colliders to probe fermionic Higgs portal and bottom quark couplings to the Z boson.

  6. Synergistic use of Lagrangian modelling, satellite- and ground-based measurements for the investigation of volcanic plumes evolution and their impact on the downwind aerosol optical and micro-physical properties: the Etna eruption of 26-27/10/2013

    NASA Astrophysics Data System (ADS)

    Sellitto, Pasquale; di Sarra, Alcide; Corradini, Stefano; Boichu, Marie; Herbin, Hervé; Dubuisson, Philippe; Sèze, Geneviève; Meloni, Daniela; Monteleone, Francesco; Merucci, Luca; Rusalem, Justin; Salerno, Giuseppe; Briole, Pierre; Legras, Bernard

    2015-04-01

    In this contribution we show how the combined use of SO2/ash plume dispersion modelling and remote observations from satellite and ground can be used to study the influence of moderate volcanic activity on the optical and micro-physical characterization of the tropospheric aerosol layer at the regional scale. We analyze the Mount Etna lava fountain and gas/ash emission episode of 26-27/10/2013. This study is based on aerosol and SO2 measurements made at the ENEA Station for Climate Observations (35.52°N, 12.63°E, 50 m asl) on Lampedusa island, on satellite observations, and on a Lagrangian model analysis. The used satellite dataset includes MODIS (MODerate resolution Imaging Spectroradiometer) true colour images, volcanic SO2/ash retrievals and flux estimations, and SEVIRI (Spinning Enhanced Visible and InfraRed Imager) cloud top pressure estimations. Trajectory analyses are made with the FLEXPART (FLEXible PARTicle dispersion model) Lagrangian dispersion model. The combination of MODIS and SEVIRI observations, FLEXPART simulations, and ground-based observations at Lampedusa indicate that SO2 and ash, despite the initial injection at about 7.0 km altitude, could have reached up to 10.0-12.0 km altitude, and influenced the aerosols size distribution downwind at a ground station, at more than 350 km distance, in the Southern sector of the Central Mediterranean. This study indicates that even a relatively small volcanic eruption can have an observable effect on the aerosol layer at the regional scale. Some arguments are given on the likely impact of the secondary sulphate aerosols formed from the conversion of the emitted SO2 on the aerosol size distribution at Lampedusa.

  7. Stringed Planar-detectors for Investigation of Rare Event Physics

    NASA Astrophysics Data System (ADS)

    Wei, Wenzhao; Mei, Dongming; Zhang, Chao; Cubed Collaboration

    2013-10-01

    In the detection of rare event physics with HPGe detectors, conventional P-type Point Contact (PPC) or coaxial detectors have no capability of discriminating electron/nuclear recoils. The CDMS-type bolometers, which possess great electron/nuclear recoils discrimination, must be operated in milli-kelvin temperature range with diffusion refrigerator at high price. Alternatively, a new idea of using great granularity and plasma time difference in pulse shape to discriminate nuclear recoils from electronic recoils with conventional germanium detectors is discussed in this paper. Stringed planar germanium detectors have been designed in a Geant4-based Monte Carlo simulation in which radiogenic backgrounds from 60Co, 40K, 238U, 232Th, and (alpha,n) neutrons have been studied. We show the anticipated sensitivity of this new detector array for detecting rare event physics including neutrinoless double-beta decay.

  8. Physical modeling of traffic with stochastic cellular automata

    SciTech Connect

    Schreckenberg, M.; Nagel, K. |

    1995-09-01

    A new type of probabilistic cellular automaton for the physical description of single and multilane traffic is presented. In this model space, time and the velocity of the cars are represented by integer numbers (as usual in cellular automata) with local update rules for the velocity. The model is very efficient for both numerical simulations and analytical investigations. The numerical results from extensive simulations reproduce very well data taken from real traffic (e.g. fundamental diagrams). Several analytical results for the model are presented as well as new approximation schemes for stationary traffic. In addition the relation to continuum hydrodynamic theory (Lighthill-Whitham) and the follow-the-leader models is discussed. The model is part of an interdisciplinary research program in Northrhine-Westfalia (``NRW Forschungsverbund Verkehrssimulation``) for the construction of a large scale microsimulation model for network traffic, supported by the government of NRW.

  9. Investigations in Experimental and Theoretical High Energy Physics

    SciTech Connect

    Krennrich, Frank

    2013-07-29

    We report on the work done under DOE grant DE-FG02-01ER41155. The experimental tasks have ongoing efforts at CERN (ATLAS), the Whipple observatory (VERITAS) and R&D work on dual readout calorimetry and neutrino-less double beta decay. The theoretical task emphasizes the weak interaction and in particular CP violation and neutrino physics. The detailed descriptions of the final report on each project are given under the appropriate task section of this report.

  10. Earthquake and slow-slip nucleation investigated with a micro-physics based seismic cycle simulator

    NASA Astrophysics Data System (ADS)

    van den Ende, Martijn; Chen, Jianye; Ampuero, Jean-Paul; Niemeijer, André

    2017-04-01

    Laboratory experiments grant essential insights into the frictional behaviour of faults over a wide range of conditions. However, these experiments are limited in the size of the test subject (the rock sample) and in their duration, which hinders the extrapolation of lab results to the scales of natural faults. Seismic cycle numerical modelling provides the means to bridge this spatial and temporal gap between laboratory experiments and nature. Modelling of the evolution of fault rock friction, leading to earthquake nucleation, and rupture propagation is commonly performed based on rate-and-state friction (RSF). While the governing equations are convenient for implementation into numerical codes, they are empirical in nature, and the absence of a physical basis for extrapolation of laboratory-derived parameters complicates the interpretation of results that are derived from such models. By contrast, analytical models based on micro-physical principles allow for an interpretation of their predictions in terms of well-defined material properties and thermodynamic quantities, but are often restricted to highly simplified geometries and boundary conditions. In this work, we present a numerical implementation of the micro-physical model proposed by Chen & Spiers (2016), which describes the interplay between granular flow and ductile creep of fault gouges, into an earthquake cycle simulator, QDYN (Luo & Ampuero, 2011). This physics-based approach offers an alternative to the rate-and-state friction laws for more detailed investigation of earthquake source mechanics. With this implementation, characteristic features typically ascribed to rate-and-state friction laws emerge spontaneously from the model, and can be related to physical properties of the material of study under the appropriate pressure and temperature conditions. We investigate the nucleation behaviour of frictional instabilities, with focus on the transition from stable creep to slow-slip and to dynamic

  11. A Multimethod Investigation Into Physical Activity in Midlife Women.

    PubMed

    Dugan, Sheila A; Karavolos, Kelly; Lynch, Elizabeth B; Hollings, Chiquia S; Fullam, Francis; Lange-Maia, Brittney S; Powell, Lynda H

    2016-12-01

    Physical inactivity in midlife women is associated with increased intra-abdominal adipose tissue development. We describe an innovative multimethod study 1) to better understand barriers to physical activity (PA) and 2) to engage midlife women to product test physical activities and identify local community-based providers and sustainable and fun PA experiences. Formative research on PA barriers from the Chicago site Study of Women's Health Across the Nation (SWAN) ancillary study of midlife women was used to develop a pilot testing measure. Feasibility, acceptability and sustainability of the PA activities were determined using the measure. Desirable locations and/or instructors were identified. The first 2 groups identified, pilot tested, and then ranked activities for their ability to promote sustained PA. The 6 top-ranked were: circuit training, total body fitness, kickboxing, Zumba, Pilates, and pedometer. The final group pilot tested highly ranked PA in 2-week blocks, and ranked pedometer and Zumba in their top 3. Consensus was reached regarding activities that could be valuable in promoting sustained PA in midlife women. Choosing convenient sites and popular instructors further facilitates sustainability. Building relationships with key community partners is essential for sustainability. Community-based participant involvement in study design is a critical element in developing a healthy living intervention.

  12. Tactile Teaching: Exploring Protein Structure/Function Using Physical Models

    ERIC Educational Resources Information Center

    Herman, Tim; Morris, Jennifer; Colton, Shannon; Batiza, Ann; Patrick, Michael; Franzen, Margaret; Goodsell, David S.

    2006-01-01

    The technology now exists to construct physical models of proteins based on atomic coordinates of solved structures. We review here our recent experiences in using physical models to teach concepts of protein structure and function at both the high school and the undergraduate levels. At the high school level, physical models are used in a…

  13. Tactile Teaching: Exploring Protein Structure/Function Using Physical Models

    ERIC Educational Resources Information Center

    Herman, Tim; Morris, Jennifer; Colton, Shannon; Batiza, Ann; Patrick, Michael; Franzen, Margaret; Goodsell, David S.

    2006-01-01

    The technology now exists to construct physical models of proteins based on atomic coordinates of solved structures. We review here our recent experiences in using physical models to teach concepts of protein structure and function at both the high school and the undergraduate levels. At the high school level, physical models are used in a…

  14. Computer Integrated Manufacturing: Physical Modelling Systems Design. A Personal View.

    ERIC Educational Resources Information Center

    Baker, Richard

    A computer-integrated manufacturing (CIM) Physical Modeling Systems Design project was undertaken in a time of rapid change in the industrial, business, technological, training, and educational areas in Australia. A specification of a manufacturing physical modeling system was drawn up. Physical modeling provides a flexibility and configurability…

  15. A Physical Model for Gravitation and Inertia

    NASA Astrophysics Data System (ADS)

    Rasor, Ned

    2011-11-01

    A physical/analytical model of gravitation and inertia is described. The model is based on proportional expansion of the universe and its contents, along with special relativistic time delay within nucleons. An expression of the gravitational constant G is derived from the model in terms of fundamental constants and properties without adjustable parameters, [ G=he^2c^2 1pt 1ptτu(mpme)^3/2=6.67x10-8cm^3g.s^2 ] where h = Planck constant, e = electronic charge, c = speed of light, mp and me are the nucleonic and electronic masses, and τu= age of the universe. The value τu = 13.6 Gy that corresponds with the accepted value of G shown is within the uncertainty of the empirical value ofτu currently estimated from cosmic ray background and other astronomical data. A modified Newtonian dynamics and other relationships derived from the model are consistent quantitatively and functionally with a variety of observed astronomical data, some of which have been considered previously to be anomalous or based on dark matter.

  16. Fuzzy modelling of Atlantic salmon physical habitat

    NASA Astrophysics Data System (ADS)

    St-Hilaire, André; Mocq, Julien; Cunjak, Richard

    2015-04-01

    Fish habitat models typically attempt to quantify the amount of available river habitat for a given fish species for various flow and hydraulic conditions. To achieve this, information on the preferred range of values of key physical habitat variables (e.g. water level, velocity, substrate diameter) for the targeted fishs pecies need to be modelled. In this context, we developed several habitat suitability indices sets for three Atlantic salmon life stages (young-of-the-year (YOY), parr, spawning adults) with the help of fuzzy logic modeling. Using the knowledge of twenty-seven experts, from both sides of the Atlantic Ocean, we defined fuzzy sets of four variables (depth, substrate size, velocity and Habitat Suitability Index, or HSI) and associated fuzzy rules. When applied to the Romaine River (Canada), median curves of standardized Weighted Usable Area (WUA) were calculated and a confidence interval was obtained by bootstrap resampling. Despite the large range of WUA covered by the expert WUA curves, confidence intervals were relatively narrow: an average width of 0.095 (on a scale of 0 to 1) for spawning habitat, 0.155 for parr rearing habitat and 0.160 for YOY rearing habitat. When considering an environmental flow value corresponding to 90% of the maximum reached by WUA curve, results seem acceptable for the Romaine River. Generally, this proposed fuzzy logic method seems suitable to model habitat availability for the three life stages, while also providing an estimate of uncertainty in salmon preferences.

  17. Evaluating nuclear physics inputs in core-collapse supernova models

    SciTech Connect

    Lentz, Eric J; Hix, William Raphael; Baird, Mark L; Messer, Bronson; Mezzacappa, Anthony

    2010-01-01

    Core-collapse supernova models depend on the details of the nuclear and weak interaction physics inputs just as they depend on the details of the macroscopic physics (transport, hydrodynamics, etc.), numerical methods, and progenitors. We present the results of our ongoing comparison studies of nuclear and weak interaction physics inputs to core collapse supernova models using the spherically-symmetric, general relativistic, neutrino radiation hydrodynamics code Agile-Boltztran. We focus on comparisons of the effects of the nuclear EoS and the effects of improving the opacities, particularly neutrino--nucleon interactions. We present the results of our ongoing comparison studies of nuclear and weak interaction physics inputs to core collapse supernova models using the spherically-symmetric, general relativistic, neutrino radiation hydrodynamics code Agile-Boltztran. We focus on comparisons of the effects of the nuclear EoS and the effects of improving the opacities, particularly neutrino--nucleon interactions. We also investigate the feedback between different EoSs and opacities in the context of different progenitors.

  18. The Usability of a Commercial Game Physics Engine to Develop Physics Educational Materials: An Investigation

    ERIC Educational Resources Information Center

    Price, Colin B.

    2008-01-01

    Commercial computer games contain "physics engine" components, responsible for providing realistic interactions among game objects. The question naturally arises of whether these engines can be used to develop educational materials for high school and university physics education. To answer this question, the author's group recently conducted a…

  19. Physical Activity during Physical Education Lessons: A Qualitative Investigation of Australian PE Teacher Perceptions

    ERIC Educational Resources Information Center

    Bennie, Andrew; Langan, Edel

    2015-01-01

    School physical education (PE) experiences play a critical role in adolescents' physical activity (PA) levels. Teachers are crucial to students' initial experiences in PA; however, limited research has explored teachers' perspectives about PA during PE using in-depth qualitative research techniques. We conducted interviews with 25 current…

  20. Physical Activity during Physical Education Lessons: A Qualitative Investigation of Australian PE Teacher Perceptions

    ERIC Educational Resources Information Center

    Bennie, Andrew; Langan, Edel

    2015-01-01

    School physical education (PE) experiences play a critical role in adolescents' physical activity (PA) levels. Teachers are crucial to students' initial experiences in PA; however, limited research has explored teachers' perspectives about PA during PE using in-depth qualitative research techniques. We conducted interviews with 25 current…

  1. The Usability of a Commercial Game Physics Engine to Develop Physics Educational Materials: An Investigation

    ERIC Educational Resources Information Center

    Price, Colin B.

    2008-01-01

    Commercial computer games contain "physics engine" components, responsible for providing realistic interactions among game objects. The question naturally arises of whether these engines can be used to develop educational materials for high school and university physics education. To answer this question, the author's group recently conducted a…

  2. Satellite attitude motion models for capture and retrieval investigations

    NASA Technical Reports Server (NTRS)

    Cochran, John E., Jr.; Lahr, Brian S.

    1986-01-01

    The primary purpose of this research is to provide mathematical models which may be used in the investigation of various aspects of the remote capture and retrieval of uncontrolled satellites. Emphasis has been placed on analytical models; however, to verify analytical solutions, numerical integration must be used. Also, for satellites of certain types, numerical integration may be the only practical or perhaps the only possible method of solution. First, to provide a basis for analytical and numerical work, uncontrolled satellites were categorized using criteria based on: (1) orbital motions, (2) external angular momenta, (3) internal angular momenta, (4) physical characteristics, and (5) the stability of their equilibrium states. Several analytical solutions for the attitude motions of satellite models were compiled, checked, corrected in some minor respects and their short-term prediction capabilities were investigated. Single-rigid-body, dual-spin and multi-rotor configurations are treated. To verify the analytical models and to see how the true motion of a satellite which is acted upon by environmental torques differs from its corresponding torque-free motion, a numerical simulation code was developed. This code contains a relatively general satellite model and models for gravity-gradient and aerodynamic torques. The spacecraft physical model for the code and the equations of motion are given. The two environmental torque models are described.

  3. Compass models: Theory and physical motivations

    NASA Astrophysics Data System (ADS)

    Nussinov, Zohar; van den Brink, Jeroen

    2015-01-01

    Compass models are theories of matter in which the couplings between the internal spin (or other relevant field) components are inherently spatially (typically, direction) dependent. A simple illustrative example is furnished by the 90° compass model on a square lattice in which only couplings of the form τixτjx (where {τia}a denote Pauli operators at site i ) are associated with nearest-neighbor sites i and j separated along the x axis of the lattice while τiyτjy couplings appear for sites separated by a lattice constant along the y axis. Similar compass-type interactions can appear in diverse physical systems. For instance, compass models describe Mott insulators with orbital degrees of freedom where interactions sensitively depend on the spatial orientation of the orbitals involved as well as the low-energy effective theories of frustrated quantum magnets, and a host of other systems such as vacancy centers, and cold atomic gases. The fundamental interdependence between internal (spin, orbital, or other) and external (i.e., spatial) degrees of freedom which underlies compass models generally leads to very rich behaviors, including the frustration of (semi-)classical ordered states on nonfrustrated lattices, and to enhanced quantum effects, prompting, in certain cases, the appearance of zero-temperature quantum spin liquids. As a consequence of these frustrations, new types of symmetries and their associated degeneracies may appear. These intermediate symmetries lie midway between the extremes of global symmetries and local gauge symmetries and lead to effective dimensional reductions. In this article, compass models are reviewed in a unified manner, paying close attention to exact consequences of these symmetries and to thermal and quantum fluctuations that stabilize orders via order-out-of-disorder effects. This is complemented by a survey of numerical results. In addition to reviewing past works, a number of other models are introduced and new results

  4. An investigation of the theoretical content of physical activity brochures

    PubMed Central

    Gainforth, Heather L.; Barg, Carolyn J.; Latimer, Amy E.; Schmid, Kristina L.; O'Malley, Deborah; Salovey, Peter

    2011-01-01

    New evidence-based physical activity guidelines and recommendations for constructing messages supplementing the guidelines have been put forth. As well, recent reviewshave identified theoretical constructs that hold promise as targets for intervention: self-regulation, outcome expectancies and self-efficacy. The purpose of this study was to examine the integration of messages targeting self-regulation, self-efficacy and outcome expectancies in existing physical activity brochures. Twenty-two PA brochures from Canadian and American National Health Organizations were assessed for their use self-efficacy, self-regulatory processes and outcome expectancies. Brochures were analyzed line-by-line using a modified version of the validated Content Analysis Approach to Theory-Specified Persuasive Educational Communication (CAATSPEC; Abraham et al., 2007). One third of the brochures were coded by two independent raters coded a third of the brochures (n = 7). Inter-rater reliability was acceptable for 17 of the 20 categories (rs> .79). Discrepancies in all categories were discussed and agreement was reached. The remaining brochures were coded by one of the two raters. Usage of thethree key theoretical constructs accounted for only 36.43% of brochure content (20.23% self-efficacy, 10.40% outcome expectancies, 5.80% self-regulation). Brochures lacked the use of a variety of theoretical strategies, specifically goal-setting, planning and verbal persuasion and rarely highlighted the affective benefits of physical activity. In the future brochures should aim to place increased emphasis on self-regulation, self-efficacy, and affective outcome expectancies. PMID:22125418

  5. Applying Machine Trust Models to Forensic Investigations

    NASA Astrophysics Data System (ADS)

    Wojcik, Marika; Venter, Hein; Eloff, Jan; Olivier, Martin

    Digital forensics involves the identification, preservation, analysis and presentation of electronic evidence for use in legal proceedings. In the presence of contradictory evidence, forensic investigators need a means to determine which evidence can be trusted. This is particularly true in a trust model environment where computerised agents may make trust-based decisions that influence interactions within the system. This paper focuses on the analysis of evidence in trust-based environments and the determination of the degree to which evidence can be trusted. The trust model proposed in this work may be implemented in a tool for conducting trust-based forensic investigations. The model takes into account the trust environment and parameters that influence interactions in a computer network being investigated. Also, it allows for crimes to be reenacted to create more substantial evidentiary proof.

  6. A Holoinformational Model of the Physical Observer

    NASA Astrophysics Data System (ADS)

    di Biase, Francisco

    2013-09-01

    The author proposes a holoinformational view of the observer based, on the holonomic theory of brain/mind function and quantum brain dynamics developed by Karl Pribram, Sir John Eccles, R.L. Amoroso, Hameroff, Jibu and Yasue, and in the quantumholographic and holomovement theory of David Bohm. This conceptual framework is integrated with nonlocal information properties of the Quantum Field Theory of Umesawa, with the concept of negentropy, order, and organization developed by Shannon, Wiener, Szilard and Brillouin, and to the theories of self-organization and complexity of Prigogine, Atlan, Jantsch and Kauffman. Wheeler's "it from bit" concept of a participatory universe, and the developments of the physics of information made by Zureck and others with the concepts of statistical entropy and algorithmic entropy, related to the number of bits being processed in the mind of the observer are also considered. This new synthesis gives a self-organizing quantum nonlocal informational basis for a new model of awareness in a participatory universe. In this synthesis, awareness is conceived as meaningful quantum nonlocal information interconnecting the brain and the cosmos, by a holoinformational unified field (integrating nonlocal holistic (quantum) and local (Newtonian). We propose that the cosmology of the physical observer is this unified nonlocal quantum-holographic cosmos manifesting itself through awareness, interconnected in a participatory holistic and indivisible way the human mind-brain to all levels of the self-organizing holographic anthropic multiverse.

  7. MSL DAN Science Investigation: Physical Simulation of DAN

    NASA Technical Reports Server (NTRS)

    Jun, Insoo

    2012-01-01

    The main objective of the proposed investigation is to study the characteristics (i.e., hydrogen content, soil composition, layer-structure, etc.) of sub-surface and the surface radiation (neutron in particular) environment.

  8. Statistical Analysis by Statistical Physics Model for the STOCK Markets

    NASA Astrophysics Data System (ADS)

    Wang, Tiansong; Wang, Jun; Fan, Bingli

    A new stochastic stock price model of stock markets based on the contact process of the statistical physics systems is presented in this paper, where the contact model is a continuous time Markov process, one interpretation of this model is as a model for the spread of an infection. Through this model, the statistical properties of Shanghai Stock Exchange (SSE) and Shenzhen Stock Exchange (SZSE) are studied. In the present paper, the data of SSE Composite Index and the data of SZSE Component Index are analyzed, and the corresponding simulation is made by the computer computation. Further, we investigate the statistical properties, fat-tail phenomena, the power-law distributions, and the long memory of returns for these indices. The techniques of skewness-kurtosis test, Kolmogorov-Smirnov test, and R/S analysis are applied to study the fluctuation characters of the stock price returns.

  9. Modelling urban rainfall-runoff responses using an experimental, two-tiered physical modelling environment

    NASA Astrophysics Data System (ADS)

    Green, Daniel; Pattison, Ian; Yu, Dapeng

    2016-04-01

    Surface water (pluvial) flooding occurs when rainwater from intense precipitation events is unable to infiltrate into the subsurface or drain via natural or artificial drainage channels. Surface water flooding poses a serious hazard to urban areas across the world, with the UK's perceived risk appearing to have increased in recent years due to surface water flood events seeming more severe and frequent. Surface water flood risk currently accounts for 1/3 of all UK flood risk, with approximately two million people living in urban areas at risk of a 1 in 200-year flood event. Research often focuses upon using numerical modelling techniques to understand the extent, depth and severity of actual or hypothetical flood scenarios. Although much research has been conducted using numerical modelling, field data available for model calibration and validation is limited due to the complexities associated with data collection in surface water flood conditions. Ultimately, the data which numerical models are based upon is often erroneous and inconclusive. Physical models offer a novel, alternative and innovative environment to collect data within, creating a controlled, closed system where independent variables can be altered independently to investigate cause and effect relationships. A physical modelling environment provides a suitable platform to investigate rainfall-runoff processes occurring within an urban catchment. Despite this, physical modelling approaches are seldom used in surface water flooding research. Scaled laboratory experiments using a 9m2, two-tiered 1:100 physical model consisting of: (i) a low-cost rainfall simulator component able to simulate consistent, uniformly distributed (>75% CUC) rainfall events of varying intensity, and; (ii) a fully interchangeable, modular plot surface have been conducted to investigate and quantify the influence of a number of terrestrial and meteorological factors on overland flow and rainfall-runoff patterns within a modelled

  10. Land Surface Emission Modeling to Support Physical Precipitation Retrievals

    NASA Technical Reports Server (NTRS)

    Peters-Lidard, Christina D.; Harrison, Kenneth; Kumar, Sujay; Ferraro, Ralph; Skofronick-Jackson, Gail

    2010-01-01

    Land surface modeling and data assimilation can provide dynamic land surface state variables necessary to support physical precipitation retrieval algorithms over land. It is well-known that surface emission, particularly over the range of frequencies to be included in the Global Precipitation Measurement Mission (GPM), is sensitive to land surface states, including soil properties, vegetation type and greenness, soil moisture, surface temperature, and snow cover, density, and grain size. In order to investigate the robustness of both the land surface model states and the microwave emissivity and forward radiative transfer models, we have undertaken a multi-site investigation as part of the NASA Precipitation Measurement Missions (PMM) Land Surface Characterization. Working Group.

  11. Physics Students' Performance Using Computational Modelling Activities to Improve Kinematics Graphs Interpretation

    ERIC Educational Resources Information Center

    Araujo, Ives Solano; Veit, Eliane Angela; Moreira, Marco Antonio

    2008-01-01

    The purpose of this study was to investigate undergraduate students' performance while exposed to complementary computational modelling activities to improve physics learning, using the software "Modellus." Interpretation of kinematics graphs was the physics topic chosen for investigation. The theoretical framework adopted was based on Halloun's…

  12. Physics Students' Performance Using Computational Modelling Activities to Improve Kinematics Graphs Interpretation

    ERIC Educational Resources Information Center

    Araujo, Ives Solano; Veit, Eliane Angela; Moreira, Marco Antonio

    2008-01-01

    The purpose of this study was to investigate undergraduate students' performance while exposed to complementary computational modelling activities to improve physics learning, using the software "Modellus." Interpretation of kinematics graphs was the physics topic chosen for investigation. The theoretical framework adopted was based on Halloun's…

  13. Physically-Based Modeling of Ecological Restoration

    NASA Astrophysics Data System (ADS)

    Brown, C.; Barros, A. P.

    2001-05-01

    The recovery and continuance of native vegetation communities is the critical component of ecological restoration. As primary producers and basis of the food web, their success will influence and likely control the recovery and sustenance of all higher tropic levels. Intact ecosystems are perfectly designed to produce the vegetation dynamics that they produce. Hence, impacted or altered ecosystems can not be perfectly designed to produce the original vegetation. The alteration of the hydrologic system of the Florida Everglades is causing well-documented changes in the composition of the ecosystem. It is argued that this composition depends on the balance between three vegetation community types, defined here as sawgrass, cattails and periphyton. The factors that may be most critical in the success of the restoration are the factors that will restore the balance between these archetypes. These factors are identified as hydroperiod, water quality (phosphorous concentration) and fire. An investigation of ecological and hydrological models was conducted to evaluate suitability of application to ecological restoration scenarios, such as the vegetation community competition of the Florida Everglades. This investigation revealed aspects of three model types, defined here as ecosystem, hydrologic and competition, are necessary for such a simulation of ecological restoration. A comparison of how each model type treats the common factors of water flow, vegetation dynamics and climate inputs revealed avenues for extension of each model type to better capture the whole system dynamics.

  14. Investigation of models for large-scale meteorological prediction experiments

    NASA Technical Reports Server (NTRS)

    Spar, J.

    1978-01-01

    The feasibility of long-range weather prediction through the use of global general circulation models (GCMs) was investigated. A climate model was developed to simulate the monthly mean state of the atmosphere from real global initial data at the beginning of the month. The model contains the same dynamic and physical ingredients as most numerical weather prediction models and GCMs. The model generates a one-day global simulation on the 8 x 10 grid in four minutes (on an IBM 360/95 computer), so that a 30 day forecast can be executed in two hours. The high speed of the model is achieved mainly at the price of its coarse resolution, which requires certain parameterizations of surface boundary conditions, as well as inherent filtering of smaller-scale features of the initial state.

  15. Investigating the Impact of Teachers' Physics CK on Students Outcomes

    ERIC Educational Resources Information Center

    Ohle, Annika; Boone, William J.; Fischer, Hans E.

    2015-01-01

    Decreasing student interest and achievement during the transition from elementary to secondary school is an international problem, especially in science education. The question of what factors influence this decline has been a widely discussed topic. This study focuses on investigating the relationship of elementary school teachers' content…

  16. Investigating the Impact of Teachers' Physics CK on Students Outcomes

    ERIC Educational Resources Information Center

    Ohle, Annika; Boone, William J.; Fischer, Hans E.

    2015-01-01

    Decreasing student interest and achievement during the transition from elementary to secondary school is an international problem, especially in science education. The question of what factors influence this decline has been a widely discussed topic. This study focuses on investigating the relationship of elementary school teachers' content…

  17. A Conceptual Model of Observed Physical Literacy

    ERIC Educational Resources Information Center

    Dudley, Dean A.

    2015-01-01

    Physical literacy is a concept that is gaining greater acceptance around the world with the United Nations Educational, Cultural, and Scientific Organization (2013) recognizing it as one of several central tenets in a quality physical education framework. However, previous attempts to understand progression in physical literacy learning have been…

  18. A Conceptual Model of Observed Physical Literacy

    ERIC Educational Resources Information Center

    Dudley, Dean A.

    2015-01-01

    Physical literacy is a concept that is gaining greater acceptance around the world with the United Nations Educational, Cultural, and Scientific Organization (2013) recognizing it as one of several central tenets in a quality physical education framework. However, previous attempts to understand progression in physical literacy learning have been…

  19. A Structural Equation Model of Conceptual Change in Physics

    ERIC Educational Resources Information Center

    Taasoobshirazi, Gita; Sinatra, Gale M.

    2011-01-01

    A model of conceptual change in physics was tested on introductory-level, college physics students. Structural equation modeling was used to test hypothesized relationships among variables linked to conceptual change in physics including an approach goal orientation, need for cognition, motivation, and course grade. Conceptual change in physics…

  20. A Structural Equation Model of Expertise in College Physics

    ERIC Educational Resources Information Center

    Taasoobshirazi, Gita; Carr, Martha

    2009-01-01

    A model of expertise in physics was tested on a sample of 374 college students in 2 different level physics courses. Structural equation modeling was used to test hypothesized relationships among variables linked to expert performance in physics including strategy use, pictorial representation, categorization skills, and motivation, and these…

  1. Kaon physics: Probing the standard model and beyond

    SciTech Connect

    Tschirhart, R.; /Fermilab

    2009-01-01

    The status and prospects of current and future kaon physics experiments is discussed. Both precision measurements and the search for and measurement of ultra-rare decays are powerful probes of many models of new physics beyond the Standard Model. The physics reach of these experiments is briefly discussed.

  2. Models for Curriculum and Pedagogy in Elementary School Physical Education

    ERIC Educational Resources Information Center

    Kulinna, Pamela Hodges

    2008-01-01

    The purpose of this article is to review current models for curriculum and pedagogy used in elementary school physical education programs. Historically, physical educators have developed and used a multiactivity curriculum in order to educate students through physical movement. More recently, a variety of alternative curricular models have been…

  3. Models Based Practices in Physical Education: A Sociocritical Reflection

    ERIC Educational Resources Information Center

    Landi, Dillon; Fitzpatrick, Katie; McGlashan, Hayley

    2016-01-01

    In this paper, we reflect on models-based practices in physical education using a sociocritical lens. Drawing links between neoliberal moves in education, and critical approaches to the body and physicality, we take a view that models are useful tools that are worth integrating into physical education, but we are apprehensive to suggest they…

  4. A Structural Equation Model of Expertise in College Physics

    ERIC Educational Resources Information Center

    Taasoobshirazi, Gita; Carr, Martha

    2009-01-01

    A model of expertise in physics was tested on a sample of 374 college students in 2 different level physics courses. Structural equation modeling was used to test hypothesized relationships among variables linked to expert performance in physics including strategy use, pictorial representation, categorization skills, and motivation, and these…

  5. Coupled pendulums: a physical system for laboratory investigations at upper secondary school

    NASA Astrophysics Data System (ADS)

    Picciarelli, Vittorio; Stella, Rosa

    2010-07-01

    The topic of coupled oscillations is rich in physical content which is both interesting and complex. The study of the time evolution of coupled oscillator systems involves a mathematical formalization beyond the level of the upper secondary school student's competence. Here, we present an original approach, suitable even for secondary students, to investigate a coupled pendulum system through a series of carefully designed hands-on and minds-on modelling activities. We give a detailed description of these activities and of the strategy developed to promote both the understanding of this complex system and a sound epistemological framework. Students are actively engaged (1) in system exploration; (2) in simple model building and its implementation with an Excel spreadsheet; and (3) in comparing the measurements of the system behaviour with predictions from the model.

  6. Physical modeling of transverse drainage mechanisms

    NASA Astrophysics Data System (ADS)

    Douglass, J. C.; Schmeeckle, M. W.

    2005-12-01

    Streams that incise across bedrock highlands such as anticlines, upwarps, cuestas, or horsts are termed transverse drainages. Their relevance today involves such diverse matters as highway and dam construction decisions, location of wildlife corridors, better-informed sediment budgets, and detailed studies into developmental histories of late Cenozoic landscapes. The transient conditions responsible for transverse drainage incision have been extensively studied on a case-by-case basis, and the dominate mechanisms proposed include: antecedence, superimposition, overflow, and piracy. Modeling efforts have been limited to antecedence, and such the specific erosional conditions required for transverse drainage incision, with respect to the individual mechanisms, remains poorly understood. In this study, fifteen experiments attempted to simulate the four mechanisms and constructed on a 9.15 m long, 2.1 m wide, and 0.45 m deep stream table. Experiments lasted between 50 and 220 minutes. The stream table was filled with seven tons of sediment consisting of a silt and clay (30%) and a fine to coarse sand (70%) mixture. The physical models highlighted the importance of downstream aggradation with regard to antecedent incision versus possible defeat and diversion. The overflow experiments indicate that retreating knickpoints across a basin outlet produce a high probability of downstream flooding when associated with a deep lake. Misters used in a couple of experiments illustrate a potential complication with regard to headward erosion driven piracy. Relatively level asymmetrically sloped ridges allow for the drainage divide across the ridge to retreat from headward erosion, but hindered when the ridge's apex undulates or when symmetrically sloped. Although these physical models cannot strictly simulate natural transverse drainages, the observed processes, their development over time, and resultant landforms roughly emulate their natural counterparts. Proposed originally from

  7. Investigation of the kinetic model equations.

    PubMed

    Liu, Sha; Zhong, Chengwen

    2014-03-01

    Currently the Boltzmann equation and its model equations are widely used in numerical predictions for dilute gas flows. The nonlinear integro-differential Boltzmann equation is the fundamental equation in the kinetic theory of dilute monatomic gases. By replacing the nonlinear fivefold collision integral term by a nonlinear relaxation term, its model equations such as the famous Bhatnagar-Gross-Krook (BGK) equation are mathematically simple. Since the computational cost of solving model equations is much less than that of solving the full Boltzmann equation, the model equations are widely used in predicting rarefied flows, multiphase flows, chemical flows, and turbulent flows although their predictions are only qualitatively right for highly nonequilibrium flows in transitional regime. In this paper the differences between the Boltzmann equation and its model equations are investigated aiming at giving guidelines for the further development of kinetic models. By comparing the Boltzmann equation and its model equations using test cases with different nonequilibrium types, two factors (the information held by nonequilibrium moments and the different relaxation rates of high- and low-speed molecules) are found useful for adjusting the behaviors of modeled collision terms in kinetic regime. The usefulness of these two factors are confirmed by a generalized model collision term derived from a mathematical relation between the Boltzmann equation and BGK equation that is also derived in this paper. After the analysis of the difference between the Boltzmann equation and the BGK equation, an attempt at approximating the collision term is proposed.

  8. Investigation of thermo-physical properties of thermal insulation coating

    NASA Astrophysics Data System (ADS)

    Kopčok, Michal; Lukovičová, Jozefa; Kačur, Jozef; Pavlendová, Gabriela

    2017-07-01

    This paper examines the thermal properties of thermal insulation coating applied to the building materials surfaces. The main objective is to determine the insulation coating impact on the heat flux transfer. The heat flux is modelled in terms of the heat transfer coefficient on the surface of a solid body. The thermal conductivity and heat transfer coefficient are obtained from the solution of the inverse heat conduction problem in 3D, based on the temperature measurements. The real temperature evolution is perturbed due to intrinsic properties of the measuring apparatus. We correct this situation via modelling a thermocouple function. Afterwards the determination procedure of the heat flux transfer parameters is a standard solution of the inverse problem based on the minimization of discrepancy between corrected measured data and computed temperature data.

  9. Investigation of self-oscillation using particle balance model

    SciTech Connect

    Bae, Inshik; Na, Byungkeun Chang, Hongyoung

    2015-08-15

    Self-oscillation obtained using a DC-only power supply under specific anode voltage conditions is investigated in a cylindrical system with thermal electrons using tungsten filaments. Analysis of the obtained oscillation profiles reveals that the experimental data are consistent with a model derived from the particle balance model. The self-oscillation period characteristics with respect to the pressure and gas species are also analyzed. As the physics and particle motion of self-oscillation near the plasma transition region are analyzed from different perspectives, this paper may advance the study of this phenomenon.

  10. Repassivation Investigations on Aluminium: Physical Chemistry of the Passive State

    NASA Astrophysics Data System (ADS)

    Nagy, Tristan Oliver; Weimerskirch, Morris Jhängi Joseph; Pacher, Ulrich; Kautek, Wolfgang

    2016-09-01

    We show the temporal change in repassivation mechanism as a time-dependent linear combination of a high-field model of oxide growth (HFM) and the point defect model (PDM). The observed switch in transient repassivation current-decrease under potentiostatic control occurs independently of the active electrode size and effective repassivation time for all applied overpotentials. For that, in situ depassivation of plasma electrolytically oxidized (PEO) coatings on aluminium was performed with nanosecond laser pulses at 266 nm and the repassivation current transients were recorded as a function of pulse number. A mathematical model combines the well established theories of oxide-film formation and growth kinetics, giving insight in the non linear transient behaviour of micro-defect passivation. According to our findings, the repassivation process can be described as a charge consumption via two concurrent channels. While the major current-decay at the very beginning of the fast healing oxide follows a point-defect type exponential damping, the HFM mechanism supersedes gradually, the longer the repassivation evolves. Furthermore, the material seems to reminisce former laser treatments via defects built-in during depassivation, leading to a higher charge contribution of the PDM mechanism at higher pulse numbers.

  11. Application of new physical chemical methods in soil ecological investigations.

    PubMed

    Motuzas, Algirdas; Vaisvalavicius, Rimantas; Prosycevas, Igoris

    2002-01-01

    The article discusses methodological investigations for the improvement and unification of soil testing in combination with the application of complex physico-chemical methods. An analytical procedure involving different extractions was used in order to determine the total and mobile amount of heavy metals (Cd, Cr, Pb, Ni, Cu, Zn, etc.) by atomic absorption spectrophotometry in soil and its fine-dispersive fraction (< 0.005 mm). The average samples (effected upon by background pollution) of Calcari Epihypogleyic Luvisol, (Lvg-p-w-cc, FAO-Unesco, 1998) has been taken from the rotation field of the experimental station of the Lithuanian University of Agriculture Subsequently, a fine-dispersive fraction was separated by a principle of peptization in distilled water. The investigation results obtained have shown a substantial dependence on the extractor used and the amount of fine-dispersive fraction in soil as well. It was found that the greatest reliability of the mobile heavy metal form is by using 1N CH3 COONH4 extractor and an HCl+HF mixture extractor for their total amount. Additionally, for the first time in Lithuania, the X-ray photoelectron spectroscopy (XPS) it has been applied for the interpretation of soil chemical composition.

  12. A mixed model reduction method for preserving selected physical information

    NASA Astrophysics Data System (ADS)

    Zhang, Jing; Zheng, Gangtie

    2017-03-01

    A new model reduction method in the frequency domain is presented. By mixedly using the model reduction techniques from both the time domain and the frequency domain, the dynamic model is condensed to selected physical coordinates, and the contribution of slave degrees of freedom is taken as a modification to the model in the form of effective modal mass of virtually constrained modes. The reduced model can preserve the physical information related to the selected physical coordinates such as physical parameters and physical space positions of corresponding structure components. For the cases of non-classical damping, the method is extended to the model reduction in the state space but still only contains the selected physical coordinates. Numerical results are presented to validate the method and show the effectiveness of the model reduction.

  13. Physical investigation of a quad confinement plasma source

    NASA Astrophysics Data System (ADS)

    Knoll, Aaron; Lucca Fabris, Andrea; Young, Christopher; Cappelli, Mark

    2016-10-01

    Quad magnetic confinement plasma sources are novel magnetized DC discharges suitable for applications in a broad range of fields, particularly space propulsion, plasma etching and deposition. These sources contain a square discharge channel with magnetic cusps at the four lateral walls, enhancing plasma confinement and electron residence time inside the device. The magnetic field topology is manipulated using four independent electromagnets on each edge of the channel, tuning the properties of the generated plasma. We characterize the plasma ejected from the quad confinement sources using a combination of traditional electrostatic probes and non-intrusive laser-based diagnostics. Measurements show a strong ion acceleration layer located 8 cm downstream of the exit plane, beyond the extent of the magnetic field. The ion velocity field is investigated with different magnetic configurations, demonstrating how ion trajectories may be manipulated. C.Y. acknowledges support from the DOE NSSA Stewardship Science Graduate Fellowship under contract DE-FC52-08NA28752.

  14. Investigating the physical basis of biomineralization. Final report

    SciTech Connect

    Dove, Patricia M.

    2001-01-01

    During the three years of this project, Professor Dove's laboratory made tremendous progress in understanding fundamental controls on crystal growth in simple model systems for the complex phenomenon of biological mineralization. Our collaboration with J.J. DeYoreo was productive and we surpassed the goals set forth in the original proposal to establish a new quantitative understanding of carbonate mineral crystallization. The findings from this project have been widely recognized across the scientific community by the award of the Mineralogical Society of America best paper award in 1998 and the Best University Research Award of 1999 at the Basic Energy sciences, Division of Geosciences ''Interfacial Processes Symposium''. In addition, two students working on this project received six different awards for their research findings.

  15. Physics of the inner heliosphere: Mechanisms, models and observational signatures

    NASA Technical Reports Server (NTRS)

    Withbroe, George L.

    1987-01-01

    Selected problems concerned with the important physical processes that occur in the corona and solar wind acceleration region, particularly time dependent phenomena were studied. Both the physics of the phenomena and the resultant effects on observational signatures, particularly spectroscopic signatures were also studied. Phenomena under study include: wave motions, particularly Alfven and fast mode waves; the formation of standing shocks in the inner heliosphere as a result of momentum and/or heat addition to the wind; and coronal transient phenomena where momentum and/or heat are deposited in the corona to produce transient plasma heating and/or mass ejection. The development of theoretical models for the inner heliosphere, the theoretical investigation of spectroscopic plasma diagnostics for this region, and the analysis of existing skylab and other relevant data are also included.

  16. Investigation and Modeling of Cranberry Weather Stress.

    NASA Astrophysics Data System (ADS)

    Croft, Paul Joseph

    Cranberry bog weather conditions and weather-related stress were investigated for development of crop yield prediction models and models to predict daily weather conditions in the bog. Field investigations and data gathering were completed at the Rutgers University Blueberry/Cranberry Research Center experimental bogs in Chatsworth, New Jersey. Study indicated that although cranberries generally exhibit little or no stomatal response to changing atmospheric conditions, the evaluation of weather-related stress could be accomplished via use of micrometeorological data. Definition of weather -related stress was made by establishing critical thresholds of the frequencies of occurrence, and magnitudes of, temperature and precipitation in the bog based on values determined by a review of the literature and a grower questionnaire. Stress frequencies were correlated with cranberry yield to develop predictive models based on the previous season's yield, prior season data, prior and current season data, current season data; and prior and current season data through July 31 of the current season. The predictive ability of the prior season models was best and could be used in crop planning and production. Further examination of bog micrometeorological data permitted the isolation of those weather conditions conducive to cranberry scald and allowed for the institution of a pilot scald advisory program during the 1991 season. The micrometeorological data from the bog was also used to develop models to predict daily canopy temperature and precipitation, based on upper air data, for grower use. Models were developed for each month for maximum and minimum temperatures and for precipitation and generally performed well. The modeling of bog weather conditions is an important first step toward daily prediction of cranberry weather-related stress.

  17. Experimental Investigation of SBLI to Unravel Inlet Unstart Physics

    NASA Astrophysics Data System (ADS)

    Funderburk, Morgan; Narayanaswamy, Venkateswaran

    2016-11-01

    The phenomenon of shock boundary layer interaction (SBLI) driven inlet unstart persists as one of the most significant problems facing supersonic ramjet/scramjet engines. In order to determine how the characteristics of the SBLI units specific to rectangular inlets evolve during an unstart event, an experimental investigation is made using surface streakline methods and pitot/wall pressure measurements in the vicinity of the floor and corner SBLI induced by a compression ramp in a rectangular channel. Mean and unsteady measurements were taken at a variety of shock strengths to simulate the evolution of the combustion-induced back pressure ratio during unstart. The freestream Mach number was also varied. Statistical correlation methods were used to determine the degree of interaction between the floor and corner SBLI with different flowfield locations for the various test conditions. Finally, comparison to a two-dimensional compression ramp SBLI was made to determine any modification caused by the introduction of the corner SBLI. Results indicate that the floor and corner SBLI transition from distinct units to members of a global separated flow with increasing back pressure, and that considerable modification of the floor SBLI by the corner flow occurs. AFOSR Grant FA9550-15-1-0296.

  18. A simple physical model for deep moonquake occurrence times

    USGS Publications Warehouse

    Weber, R.C.; Bills, B.G.; Johnson, C.L.

    2010-01-01

    The physical process that results in moonquakes is not yet fully understood. The periodic occurrence times of events from individual clusters are clearly related to tidal stress, but also exhibit departures from the temporal regularity this relationship would seem to imply. Even simplified models that capture some of the relevant physics require a large number of variables. However, a single, easily accessible variable - the time interval I(n) between events - can be used to reveal behavior not readily observed using typical periodicity analyses (e.g., Fourier analyses). The delay-coordinate (DC) map, a particularly revealing way to display data from a time series, is a map of successive intervals: I(n+. 1) plotted vs. I(n). We use a DC approach to characterize the dynamics of moonquake occurrence. Moonquake-like DC maps can be reproduced by combining sequences of synthetic events that occur with variable probability at tidal periods. Though this model gives a good description of what happens, it has little physical content, thus providing only little insight into why moonquakes occur. We investigate a more mechanistic model. In this study, we present a series of simple models of deep moonquake occurrence, with consideration of both tidal stress and stress drop during events. We first examine the behavior of inter-event times in a delay-coordinate context, and then examine the output, in that context, of a sequence of simple models of tidal forcing and stress relief. We find, as might be expected, that the stress relieved by moonquakes influences their occurrence times. Our models may also provide an explanation for the opposite-polarity events observed at some clusters. ?? 2010.

  19. Tool for physics beyond the standard model

    NASA Astrophysics Data System (ADS)

    Newby, Christopher A.

    The standard model (SM) of particle physics is a well studied theory, but there are hints that the SM is not the final story. What the full picture is, no one knows, but this thesis looks into three methods useful for exploring a few of the possibilities. To begin I present a paper by Spencer Chang, Nirmal Raj, Chaowaroj Wanotayaroj, and me, that studies the Higgs boson. The scalar particle first seen in 2012 may be the vanilla SM version, but there is some evidence that its couplings are different than predicted. By means of increasing the Higgs' coupling to vector bosons and fermions, we can be more consistent with the data. Next, in a paper by Spencer Chang, Gabriel Barello, and me, we elaborate on a tool created to study dark matter (DM) direct detection. The original work by Anand. et al. focused on elastic dark matter, whereas we extended this work to include the in elastic case, where different DM mass states enter and leave the collision. We also examine several direct detection experiments with our new framework to see if DAMA's modulation can be explained while avoiding the strong constraints imposed by the other experiments. We find that there are several operators that can do this. Finally, in a paper by Spencer Chang, Gabriel Barello, and me, we study an interesting phenomenon know as kinetic mixing, where two gauge bosons can share interactions with particles even though these particles aren't charged under both gauge groups. This, in and of itself, is not new, but we discuss a different method of obtaining this mixing where instead of mixing between two Abelian groups one of the groups is Nonabelian. Using this we then see that there is an inherent mass scale in the mixing strength; something that is absent in the Abelian-Abelian case. Furthermore, if the Nonabelian symmetry is the SU(2)L of the SM then the mass scale of the physics responsible for the mixing is about 1 TeV, right around the sweet spot for detection at the LHC. This dissertation

  20. Engaging Students In Modeling Instruction for Introductory Physics

    NASA Astrophysics Data System (ADS)

    Brewe, Eric

    2016-05-01

    Teaching introductory physics is arguably one of the most important things that a physics department does. It is the primary way that students from other science disciplines engage with physics and it is the introduction to physics for majors. Modeling instruction is an active learning strategy for introductory physics built on the premise that science proceeds through the iterative process of model construction, development, deployment, and revision. We describe the role that participating in authentic modeling has in learning and then explore how students engage in this process in the classroom. In this presentation, we provide a theoretical background on models and modeling and describe how these theoretical elements are enacted in the introductory university physics classroom. We provide both quantitative and video data to link the development of a conceptual model to the design of the learning environment and to student outcomes. This work is supported in part by DUE #1140706.

  1. Modelling Mathematical Reasoning in Physics Education

    ERIC Educational Resources Information Center

    Uhden, Olaf; Karam, Ricardo; Pietrocola, Mauricio; Pospiech, Gesche

    2012-01-01

    Many findings from research as well as reports from teachers describe students' problem solving strategies as manipulation of formulas by rote. The resulting dissatisfaction with quantitative physical textbook problems seems to influence the attitude towards the role of mathematics in physics education in general. Mathematics is often seen as a…

  2. Modelling Mathematical Reasoning in Physics Education

    ERIC Educational Resources Information Center

    Uhden, Olaf; Karam, Ricardo; Pietrocola, Mauricio; Pospiech, Gesche

    2012-01-01

    Many findings from research as well as reports from teachers describe students' problem solving strategies as manipulation of formulas by rote. The resulting dissatisfaction with quantitative physical textbook problems seems to influence the attitude towards the role of mathematics in physics education in general. Mathematics is often seen as a…

  3. Self-Determination Theory as an Organizing Framework To Investigate Women's Physical Activity Behavior.

    ERIC Educational Resources Information Center

    Landry, Joan B.; Solmon, Melinda A.

    2002-01-01

    Explores the literature on the status of women's health behavior and the benefits of physical activity, using Self- Determination Theory (SDT) as an organizing framework and including the Health Belief Model and Transtheoretical Model in the framework. Women's physical activity behaviors are examined through the lens of SDT with the intention of…

  4. Advanced in turbulence physics and modeling by direct numerical simulations

    NASA Technical Reports Server (NTRS)

    Reynolds, W. C.

    1987-01-01

    The advent of direct numerical simulations of turbulence has opened avenues for research on turbulence physics and turbulence modeling. Direct numerical simulation provides values for anything that the scientist or modeler would like to know about the flow. An overview of some recent advances in the physical understanding of turbulence and in turbulence modeling obtained through such simulations is presented.

  5. Teacher Fidelity to One Physical Education Curricular Model

    ERIC Educational Resources Information Center

    Kloeppel, Tiffany; Kulinna, Pamela Hodges; Stylianou, Michalis; van der Mars, Hans

    2013-01-01

    This study addressed teachers' fidelity to one Physical Education curricular model. The theoretical framework guiding this study included professional development and fidelity to curricular models. In this study, teachers' fidelity to the Dynamic Physical Education (DPE) curricular model was measured for high and nonsupport district groups.…

  6. Teacher Fidelity to One Physical Education Curricular Model

    ERIC Educational Resources Information Center

    Kloeppel, Tiffany; Kulinna, Pamela Hodges; Stylianou, Michalis; van der Mars, Hans

    2013-01-01

    This study addressed teachers' fidelity to one Physical Education curricular model. The theoretical framework guiding this study included professional development and fidelity to curricular models. In this study, teachers' fidelity to the Dynamic Physical Education (DPE) curricular model was measured for high and nonsupport district groups.…

  7. ATOMIC AND MOLECULAR PHYSICS: Modelling of a DNA packaging motor

    NASA Astrophysics Data System (ADS)

    Qian, Jun; Xie, Ping; Xue, Xiao-Guang; Wang, Peng-Ye

    2009-11-01

    During the assembly of many viruses, a powerful molecular motor packages the genome into a preassembled capsid. The Bacillus subtilis phage phi29 is an excellent model system to investigate the DNA packaging mechanism because of its highly efficient in vitro DNA packaging activity and the development of a single-molecule packaging assay. Here we make use of structural and biochemical experimental data to build a physical model of DNA packaging by the phi29 DNA packaging motor. Based on the model, various dynamic behaviours such as the packaging rate, pause frequency and slip frequency under different ATP concentrations, ADP concentrations, external loads as well as capsid fillings are studied by using Monte Carlo simulation. Good agreement is obtained between the simulated and available experimental results. Moreover, we make testable predictions that should guide future experiments related to motor function.

  8. We need more empirical investigations and model validation for a better understanding of crime. Comment on "Statistical physics of crime: A review" by M.R. D'Orsogna and M. Perc

    NASA Astrophysics Data System (ADS)

    Ribeiro, Haroldo V.

    2015-03-01

    Since the seminal works of Wilson and Kelling [1] in 1982, the "broken windows theory" seems to have been widely accepted among the criminologists and, in fact, empirical findings actually point out that criminals tend to return to previously visited locations. Crime has always been part of the urban society's agenda and has also attracted the attention of scholars from social sciences ever since. Furthermore, over the past six decades the world has experienced a quick and notorious urbanization process: by the eighties the urban population was about 40% of total population, and today more than half (54%) of the world population is urban [2]. The urbanization has brought us many benefits such as better working opportunities and health care, but has also created several problems such as pollution and a considerable rise in the criminal activities. In this context of urban problems, crime deserves a special attention because there is a huge necessity of empirical and mathematical (modeling) investigations which, apart from the natural academic interest, may find direct implications for the organization of our society by improving political decisions and resource allocation.

  9. Experimental investigations in particle physics at intermediate energies

    SciTech Connect

    Auerbach, L.B.; Highland, V.L.; Martoff, C.J.; McFarlane, K.W.; Guss, C.; Kettell, S.

    1991-09-30

    The major elements of this project continues to be on fundamental symmetries and parameters of the Standard Model. The projects in the current period have been BNL E791 (a search for the decay K{sub L}{sup 0} {yields} {mu}e, which would violate the rule of separate lepton number conservation), test of an upgrade proposal (E871), and LSND, a neutrino experiment at LAMPF. For E791, data taking was completed in June 1990, and preliminary results are now available for the decays K{sub L}{sup 0} {yields} {mu}e and K{sub L}{sup 0} {yields} {mu}{mu}from the entire data set. The data for decay K{sub L}{sup 0} {yields} ee are still being analysed. These are an upper limit for the branching fraction for K{sub L}{sup 0} {yields} {mu}e of 3.5 {times} 10{sup {minus}11} (90% C.L.). From the 1990 data alone, we have a new (preliminary) value of the branching fraction for K{sub L}{sup 0} {yields} {mu}{mu} of (6.96{plus minus}0. 4{plus minus}0.22) {times} 10{sup {minus}9}, with a sample of 349 events. Combining this with earlier data gives (6.96{plus minus}0.34) {times} 10{sup 9}, by far the most precise value. The limit on the decay K{sub L}{sup 0} {yields} {mu}e places a lower limit on the mass of a new particle mediating such decays of 85 TeV. The LSND (Large Scintillator Neutrino Detector), a search for neutrino oscillations at LAMPF, has been approved, and is now underway. Other neutrino work at Los Alamos, E764, has resulted in a final publication. This includes the best, measurement of {nu}-nuclear scattering, in {nu}{sub mu} {sup 12}C inclusive cross sections. The measurement of the cross section for the exclusive reaction {nu}{sup mu}{sup 12}C {yields} {mu}{sup {minus}12} N is unique. In a new development, Dr. Martoff has established a facility for fabrication of superconducting detectors of nuclear radiation; the equipment has been funded and is partly installed. Planned uses include scattering for Dark Matter.' In summary, the objectives for this year have been met.

  10. Intentional Development: A Model to Guide Lifelong Physical Activity

    ERIC Educational Resources Information Center

    Cherubini, Jeffrey M.

    2009-01-01

    Framed in the context of researching influences on physical activity and actually working with individuals and groups seeking to initiate, increase or maintain physical activity, the purpose of this review is to present the model of Intentional Development as a multi-theoretical approach to guide research and applied work in physical activity.…

  11. Physical and Numerical Modeling of Buoyant Groundwater Plumes

    NASA Astrophysics Data System (ADS)

    Brakefield, L. K.; Abarca, E.; Langevin, C. D.; Clement, T. P.

    2007-12-01

    In coastal states, the injection of treated wastewater into deep saline aquifers offers a disposal alternative to ocean outfalls and discharge directly into local waterways. The density of treated wastewater is similar to that of freshwater but is often much lower than the ambient density of deep aquifers. This significant density contrast can cause upward buoyant movement of the wastewater plume during and after injection. Since some wastewater treatment plants inject more than 100 MGD of this treated wastewater, it is of the utmost importance to be able to not only determine the fate and transport rates of the plume, but to be able to best determine locations for monitoring wells for early detection of possible problems. In this study, both physical and numerical modeling were undertaken to investigate and understand buoyant plume behavior and transport. Physical models using a 2D cross-sectional Plexiglas tank filled with glass beads were carried out under different ambient density scenarios. The experiments consisted of injection of a freshwater pulse-source bubble into a fully saline tank. The injection occurred in an initially static system with no ambient flow. In the scenarios, the freshwater plume migrated vertically upward until reaching the top of the tank. Fingers developed because of the heterogeneity of the density dependent flow field. The vertical velocities and transport patterns of these plumes were compared to one another to investigate variances due to different ambient water densities. Using the finite-difference numerical code SEAWAT to simulate variable density flow, the experiments were numerically modeled and compared with the physical model results. Due to the sensitivity of this problem to numerical resolution, results from three different grids were compared to determine a reasonable compromise between computer runtimes and numerical accuracy. Furthermore, a comparison of advection solvers was undertaken to identify the best solver to

  12. High school students' scientific epistemological beliefs, self-efficacy in learning physics and attitudes toward physics: a structural equation model

    NASA Astrophysics Data System (ADS)

    Kapucu, Serkan; Bahçivan, Eralp

    2015-05-01

    Background: There are some theoretical evidences that explain the relationships between core beliefs (i.e., epistemological beliefs) and peripheral beliefs (self-efficacy in learning) in the literature. The close relationships of such type of beliefs with attitudes are also discussed by some researchers. Constructing a model that investigates these relationships by considering theoretical and empirical evidences can empower researchers to discuss these relationships more comprehensively. Purpose: The purpose of this study is to explore the relationships among Turkish high school students' scientific epistemological beliefs, self-efficacy in learning physics and their attitudes toward physics. Sample: A total of 632 high school students participated in this study; however, 269 female and 229 male (a total of 498) high school students' data were used. Design and methods: Three distinct instruments that measure scientific epistemological beliefs, self-efficacy in learning physics and attitudes toward physics were combined into a unique questionnaire form and it was distributed to high school students. To explore the relationships among these variables, structural equation modeling was used. Results: The results showed that scientific epistemological belief dimensions uncovered by the nature of knowing (source and justification) significantly and positively related to both self-efficacy in learning physics and attitudes toward other important physics dimensions. Additionally, self-efficacy in learning physics significantly and positively predicted attitudes toward multiple physics dimensions (importance, comprehension and requirement). However, epistemological belief dimensions related to the nature of knowledge (certainty and development) did not have significant impact on self-efficacy in learning physics or attitudes toward physics. Conclusions: This study concludes that there are positive and significant relationships among Turkish high school students' scientific

  13. Modelling surface water flood risk using coupled numerical and physical modelling techniques

    NASA Astrophysics Data System (ADS)

    Green, D. L.; Pattison, I.; Yu, D.

    2015-12-01

    Surface water (pluvial) flooding occurs due to intense precipitation events where rainfall cannot infiltrate into the sub-surface or drain via storm water systems. The perceived risk appears to have increased in recent years with pluvial flood events seeming more severe and frequent within the UK. Surface water flood risk currently accounts for one third of all UK flood risk, with approximately two million people living in urban areas being at risk of a 1 in 200 year flood event. Surface water flooding research often focuses upon using 1D, 2D or 1D-2D coupled numerical modelling techniques to understand the extent, depth and severity of actual or hypothetical flood scenarios. Although much research has been conducted using numerical modelling, field data available for model calibration and validation is limited due to the complexities associated with data collection in surface water flood conditions. Ultimately, the data which numerical models are based upon is often erroneous and inconclusive. Physical models offer an alternative and innovative environment to collect data within. A controlled, closed system allows independent variables to be altered individually to investigate cause and effect relationships. Despite this, physical modelling approaches are seldom used in surface water flooding research. Scaled laboratory experiments using a 9m2, two-tiered physical model consisting of: (i) a mist nozzle type rainfall simulator able to simulate a range of rainfall intensities similar to those observed within the United Kingdom, and; (ii) a fully interchangeable, scaled plot surface have been conducted to investigate and quantify the influence of factors such as slope, impermeability, building density/configuration and storm dynamics on overland flow and rainfall-runoff patterns within a range of terrestrial surface conditions. Results obtained within the physical modelling environment will be compared with numerical modelling results using FloodMap (Yu & Lane, 2006

  14. Physical activity for people with a disability: a conceptual model.

    PubMed

    van der Ploeg, Hidde P; van der Beek, Allard J; van der Woude, Luc H V; van Mechelen, Willem

    2004-01-01

    The promotion of a physically active lifestyle has become an important issue in health policy in first-world countries. A physically active lifestyle is accompanied by several fitness and health benefits. Individuals with a disability can particularly benefit from an active lifestyle: not only does it reduce the risk for secondary health problems, but all levels of functioning can be influenced positively. The objective of this article is to propose a conceptual model that describes the relationships between physical activity behaviour, its determinants and functioning of people with a disability. The literature was systematically searched for articles considering physical activity and disability, and models relating both topics were looked for in particular. No models were found relating physical activity behaviour, its determinants and functioning in people with a disability. Consequently, a new model, the Physical Activity for people with a Disability (PAD) model, was constructed based on existing models of disability and models of determinants of physical activity behaviour. The starting point was the new WHO Model of Functioning and Disability, part of the International Classification of Functioning, Disability and Health (ICF), which describes the multidimensional aspects of functioning and disability. Physical activity behaviour and its determinants were integrated into the ICF model. The factors determining physical activity were based mainly on those used in the Attitude, Social influence and self-Efficacy (ASE) model. The proposed model can be used as a theoretical framework for future interventions and research on physical activity promotion in the population of people with a disability. The model currently forms the theoretical basis for a large physical activity promotion trial in ten Dutch rehabilitation centres.

  15. Investigation of Interference Models for RFID Systems.

    PubMed

    Zhang, Linchao; Ferrero, Renato; Gandino, Filippo; Rebaudengo, Maurizio

    2016-02-04

    The reader-to-reader collision in an RFID system is a challenging problem for communications technology. In order to model the interference between RFID readers, different interference models have been proposed, mainly based on two approaches: single and additive interference. The former only considers the interference from one reader within a certain range, whereas the latter takes into account the sum of all of the simultaneous interferences in order to emulate a more realistic behavior. Although the difference between the two approaches has been theoretically analyzed in previous research, their effects on the estimated performance of the reader-to-reader anti-collision protocols have not yet been investigated. In this paper, the influence of the interference model on the anti-collision protocols is studied by simulating a representative state-of-the-art protocol. The results presented in this paper highlight that the use of additive models, although more computationally intensive, is mandatory to improve the performance of anti-collision protocols.

  16. Classical Cepheid Pulsation Models. IX. New Input Physics

    NASA Astrophysics Data System (ADS)

    Petroni, Silvia; Bono, Giuseppe; Marconi, Marcella; Stellingwerf, Robert F.

    2003-12-01

    We constructed several sequences of classical Cepheid envelope models at solar chemical composition (Y=0.28,Z=0.02) to investigate the dependence of the pulsation properties predicted by linear and nonlinear hydrodynamic models on input physics. To study the dependence on the equation of state (EOS) we performed several numerical experiments by using the simplified analytical EOS originally developed by Stellingwerf and the recent analytical EOS developed by Irwin. Current findings suggest that the pulsation amplitudes, as well as the topology of the instability strip, marginally depend on the adopted EOS. To compromise between accuracy and numerical complexity we computed new EOS tables using the Irwin analytical EOS. We found that the difference between analytical and tabular thermodynamic quantities and their derivatives are smaller than 2% when adopting suitable steps in temperature and density. To improve the numerical accuracy of physical quantities, we are now adopting bicubic splines to interpolate both opacity and EOS tables. The new approach presents a substantial advantage to avoiding numerical derivatives in both linear and nonlinear models. The EOS first- and second-order derivatives are estimated by means of the analytical EOS or by means of analytical derivatives of the interpolating function. The opacity first-order derivatives are evaluated by means of analytical derivatives of the interpolating function. We also investigated the dependence of observables predicted by theoretical models on the mass-luminosity (ML) relation and on the spatial resolution across the hydrogen and the helium partial ionization regions. We found that nonlinear models are marginally affected by these physical and numerical assumptions. In particular, the difference between new and old models in the location as well as in the temperature width of the instability strip is, on average, less than 200 K. However, the spatial resolution somehow affects the pulsation properties

  17. Investigating surface and subsurface physical properties of small bodies from light scattering observations and simulations

    NASA Astrophysics Data System (ADS)

    Levasseur-Regourd, A. C.; Hadamcik, E.; Lasue, J.; Renard, J. B.

    Investigating surface and subsurface physical properties of small bodies from light scattering observations and simulations A.C. Levasseur-Regourd (1), E. Hadamcik (1), J. Lasue (1), J.B. Renard (2) (1) Université Pierre et Marie Curie-Paris6, UMR 7620, Aéronomie, BP-3, Verrières, 91371 France, (2) LPCE-CNRS, 3A av. Recherche Scientifique, Orléans, F-45071 France Investigating surface and subsurface physical properties of asteroids and comet nuclei is of major interest to i) assess future space missions and ii) constrain formation and evolution models. Our purpose is to infer such properties from the properties of solar light scattered by such media. We will first summarize recent remote polarimetric observations of small bodies, which confirm the main characteristics of the variation of the linear polarization of solar scattered light in the visible domain with the scattering geometry and the wavelength (1). To interpret such characteristics in terms of physical properties of the regoliths (e.g. albedo, size distribution, complex refractive index, porosity), experimental and numerical simulations on various types of particles and aggregates are mandatory, together with some comparisons between experimental and numerical simulations (2,3). We will thus present recent results of such simulations (for dust around bright comets, for core-mantle particles, for loose deposited transparent and dark materials), and point out the trends already suggested by this approach. Finally, we will mention future key observations and elaborate simulations, which could solve open questions about surface and subsurface properties of small bodies. References 1. Levasseur-Regourd et al., ASR 37, 161, 2006. 2. Hadamcik et al., JQSRT 100, 143, 2006. 3. Lasue et al., JQSRT 100, 220, 2006.

  18. TOWARD EFFICIENT RIPARIAN RESTORATION: INTEGRATING ECONOMIC, PHYSICAL, AND BIOLOGICAL MODELS

    EPA Science Inventory

    This paper integrates economic, biological, and physical models to determine the efficient combination and spatial allocation of conservation efforts for water quality protection and salmonid habitat enhancement in the Grande Ronde basin, Oregon. The integrated modeling system co...

  19. TOWARD EFFICIENT RIPARIAN RESTORATION: INTEGRATING ECONOMIC, PHYSICAL, AND BIOLOGICAL MODELS

    EPA Science Inventory

    This paper integrates economic, biological, and physical models to determine the efficient combination and spatial allocation of conservation efforts for water quality protection and salmonid habitat enhancement in the Grande Ronde basin, Oregon. The integrated modeling system co...

  20. Investigation of the Perceived Causes of Pre-Service Physics Teachers' Problems Encountered in School Experience

    ERIC Educational Resources Information Center

    Körhasan, Nilüfer Didis; Didis, M. Gözde

    2015-01-01

    This study investigates a group of pre-service physics teachers' perceptions about the causes of problems in school experience through the attribution theory. The participants were thirteen pre-service physics teachers from a public university in Turkey. Data were collected through the interviews by requesting the participants to reflect their own…

  1. An Investigation of Teacher Candidates' Perceptions about Physical Dimension of Classroom Management

    ERIC Educational Resources Information Center

    Bulut Ozsezer, M. Sencer; Iflazoglu Saban, Ayten

    2017-01-01

    The purpose of this research is to investigate teacher candidates' perceptions about the physical dimension of classroom management. A hundred two 3rd year students at the Primary School Education Department of a state university were instructed to visit a primary school and to observe a classroom in terms of its physical dimensions. The students…

  2. Investigation of Global Citizenship Levels of Pre-Service Physical Education Teachers

    ERIC Educational Resources Information Center

    Kayisoglu, Numan Bahadir

    2016-01-01

    The purpose of the present research is to define global citizenship levels of pre-service physical education teachers and investigate whether their global citizenship levels vary by various variables. A total of 485 pre-service teachers, studying at 3rd and 4th grades of undergraduate programs of physical education teaching at thirteen different…

  3. An Empirical Investigation of the Dimensionality of the Physical Literacy Environment in Early Childhood Classrooms

    ERIC Educational Resources Information Center

    Dynia, Jaclyn M.; Schachter, Rachel E.; Piasta, Shayne B.; Justice, Laura M.; O'Connell, Ann A.; Yeager Pelatti, Christina

    2016-01-01

    This study investigated the dimensionality of the physical literacy environment of early childhood education classrooms. Data on the classroom physical literacy environment were collected from 245 classrooms using the Classroom Literacy Observation Profile. A combination of confirmatory and exploratory factor analysis was used to identify five…

  4. Investigation of a Chaotic Double Pendulum in the Basic Level Physics Teaching Laboratory

    ERIC Educational Resources Information Center

    Vanko, Peter

    2007-01-01

    First-year physics students at the Technical University of Budapest carry out a wide range of measurements in the Basic Level Physics Teaching Laboratory. One of the most exciting experiments is the investigation of a chaotic double pendulum by a V-scope, a powerful three-dimensional motion tracking system. After a brief introduction to the…

  5. The Effect of Modeling and Visualization Resources on Student Understanding of Physical Hydrology

    ERIC Educational Resources Information Center

    Marshall, Jilll A.; Castillo, Adam J.; Cardenas, M. Bayani

    2015-01-01

    We investigated the effect of modeling and visualization resources on upper-division, undergraduate and graduate students' performance on an open-ended assessment of their understanding of physical hydrology. The students were enrolled in one of five sections of a physical hydrology course. In two of the sections, students completed homework…

  6. The Effect of Modeling and Visualization Resources on Student Understanding of Physical Hydrology

    ERIC Educational Resources Information Center

    Marshall, Jilll A.; Castillo, Adam J.; Cardenas, M. Bayani

    2015-01-01

    We investigated the effect of modeling and visualization resources on upper-division, undergraduate and graduate students' performance on an open-ended assessment of their understanding of physical hydrology. The students were enrolled in one of five sections of a physical hydrology course. In two of the sections, students completed homework…

  7. An Empirical-Mathematical Modelling Approach to Upper Secondary Physics

    ERIC Educational Resources Information Center

    Angell, Carl; Kind, Per Morten; Henriksen, Ellen K.; Guttersrud, Oystein

    2008-01-01

    In this paper we describe a teaching approach focusing on modelling in physics, emphasizing scientific reasoning based on empirical data and using the notion of multiple representations of physical phenomena as a framework. We describe modelling activities from a project (PHYS 21) and relate some experiences from implementation of the modelling…

  8. An Empirical-Mathematical Modelling Approach to Upper Secondary Physics

    ERIC Educational Resources Information Center

    Angell, Carl; Kind, Per Morten; Henriksen, Ellen K.; Guttersrud, Oystein

    2008-01-01

    In this paper we describe a teaching approach focusing on modelling in physics, emphasizing scientific reasoning based on empirical data and using the notion of multiple representations of physical phenomena as a framework. We describe modelling activities from a project (PHYS 21) and relate some experiences from implementation of the modelling…

  9. Assessing the Integration of Computational Modeling and ASU Modeling Instruction in the High School Physics Classroom

    NASA Astrophysics Data System (ADS)

    Aiken, John; Schatz, Michael; Burk, John; Caballero, Marcos; Thoms, Brian

    2012-03-01

    We describe the assessment of computational modeling in a ninth grade classroom in the context of the Arizona Modeling Instruction physics curriculum. Using a high-level programming environment (VPython), students develop computational models to predict the motion of objects under a variety of physical situations (e.g., constant net force), to simulate real world phenomenon (e.g., car crash), and to visualize abstract quantities (e.g., acceleration). The impact of teaching computation is evaluated through a proctored assignment that asks the students to complete a provided program to represent the correct motion. Using questions isomorphic to the Force Concept Inventory we gauge students understanding of force in relation to the simulation. The students are given an open ended essay question that asks them to explain the steps they would use to model a physical situation. We also investigate the attitudes and prior experiences of each student using the Computation Modeling in Physics Attitudinal Student Survey (COMPASS) developed at Georgia Tech as well as a prior computational experiences survey.

  10. Investigating Students' Ideas About X-rays While Developing Teaching Materials for a Medical Physics Course

    SciTech Connect

    Kalita, Spartak; Zollman, Dean

    2007-01-30

    The goal of the Modern Miracle Medical Machines project is to promote pre-med students' interest in physics by using the context of contemporary medical imaging. The X-ray medical imaging learning module will be a central part of this effort. To investigate students' transfer of learning in this context we have conducted a series of clinical and teaching interviews. In the latter interview, some of the proposed learning materials were used. The students brought to our discussion pieces of knowledge transferred from very different sources such as their own X-ray experiences, previous learning and the mass media. This transfer seems to result in more or less firm mental models which often are not always internally consistent or coherent.

  11. A multi-physics model for ultrasonically activated soft tissue.

    PubMed

    Suvranu De, Rahul

    2017-02-01

    A multi-physics model has been developed to investigate the effects of cellular level mechanisms on the thermomechanical response of ultrasonically activated soft tissue. Cellular level cavitation effects have been incorporated in the tissue level continuum model to accurately determine the thermodynamic states such as temperature and pressure. A viscoelastic material model is assumed for the macromechanical response of the tissue. The cavitation model based equation-of-state provides the additional pressure arising from evaporation of intracellular and cellular water by absorbing heat due to structural and viscoelastic heating in the tissue, and temperature to the continuum level thermomechanical model. The thermomechanical response of soft tissue is studied for the operational range of frequencies of oscillations and applied loads for typical ultrasonically activated surgical instruments. The model is shown to capture characteristics of ultrasonically activated soft tissue deformation and temperature evolution. At the cellular level, evaporation of water below the boiling temperature under ambient conditions is indicative of protein denaturation around the temperature threshold for coagulation of tissues. Further, with increasing operating frequency (or loading), the temperature rises faster leading to rapid evaporation of tissue cavity water, which may lead to accelerated protein denaturation and coagulation.

  12. Using the Bifocal Modeling Framework to Resolve "Discrepant Events" between Physical Experiments and Virtual Models in Biology

    ERIC Educational Resources Information Center

    Blikstein, Paulo; Fuhrmann, Tamar; Salehi, Shima

    2016-01-01

    In this paper, we investigate an approach to supporting students' learning in science through a combination of physical experimentation and virtual modeling. We present a study that utilizes a scientific inquiry framework, which we call "bifocal modeling," to link student-designed experiments and computer models in real time. In this…

  13. Using the Bifocal Modeling Framework to Resolve "Discrepant Events" between Physical Experiments and Virtual Models in Biology

    ERIC Educational Resources Information Center

    Blikstein, Paulo; Fuhrmann, Tamar; Salehi, Shima

    2016-01-01

    In this paper, we investigate an approach to supporting students' learning in science through a combination of physical experimentation and virtual modeling. We present a study that utilizes a scientific inquiry framework, which we call "bifocal modeling," to link student-designed experiments and computer models in real time. In this…

  14. Modeling the Discrimination Power of Physics Items

    ERIC Educational Resources Information Center

    Mesic, Vanes

    2011-01-01

    For the purposes of tailoring physics instruction in accordance with the needs and abilities of the students it is useful to explore the knowledge structure of students of different ability levels. In order to precisely differentiate the successive, characteristic states of student achievement it is necessary to use test items that possess…

  15. An Amotivation Model in Physical Education

    ERIC Educational Resources Information Center

    Shen, Bo; Wingert, Robert K.; Li, Weidong; Sun, Haichun; Rukavina, Paul Bernard

    2010-01-01

    Amotivation refers to a state in which individuals cannot perceive a relationship between their behavior and that behavior's subsequent outcome. With the belief that considering amotivation as a multidimensional construct could reflect the complexity of motivational deficits in physical education, we developed this study to validate an amotivation…

  16. A SUPER Model for Teaching Physics.

    ERIC Educational Resources Information Center

    Hayes, Robert E.

    1985-01-01

    Compares and contrasts high school physics philosophies, curricula, and textbooks of early 1900s to present, indicating that current textbooks are teacher and subject-oriented, lack examples of daily life, and are highly mathematical and too abstract. Suggestions for helping students experience success and improve self-esteem (which leads to…

  17. Simultaneous optical and mechanical probes to investigate complex cellular responses to physical cues

    NASA Astrophysics Data System (ADS)

    Haase, Kristina; Al-Rekabi, Zeinab; Guolla, Louise; Hickey, Ryan; Tremblay, Dominique; Pelling, Andrew E.

    2015-03-01

    Living cells possess an exquisite ability to sense and respond to physical information in their microenvironment. This ability plays a key role in many fundamentally important physiological and pathological processes. We will describe our work utilizing a variety of biophysical tools to investigate the dynamic responses of cells to mechanical stimuli and how physical cues can be employed to re-purpose and manipulate biological processes. These responses to physical cues are not simply a side-product of biology but are key components of biological and physical feedback loops that govern the life of a cell.

  18. Testing a Theoretical Model of Immigration Transition and Physical Activity.

    PubMed

    Chang, Sun Ju; Im, Eun-Ok

    2015-01-01

    The purposes of the study were to develop a theoretical model to explain the relationships between immigration transition and midlife women's physical activity and test the relationships among the major variables of the model. A theoretical model, which was developed based on transitions theory and the midlife women's attitudes toward physical activity theory, consists of 4 major variables, including length of stay in the United States, country of birth, level of acculturation, and midlife women's physical activity. To test the theoretical model, a secondary analysis with data from 127 Hispanic women and 123 non-Hispanic (NH) Asian women in a national Internet study was used. Among the major variables of the model, length of stay in the United States was negatively associated with physical activity in Hispanic women. Level of acculturation in NH Asian women was positively correlated with women's physical activity. Country of birth and level of acculturation were significant factors that influenced physical activity in both Hispanic and NH Asian women. The findings support the theoretical model that was developed to examine relationships between immigration transition and physical activity; it shows that immigration transition can play an essential role in influencing health behaviors of immigrant populations in the United States. The NH theoretical model can be widely used in nursing practice and research that focus on immigrant women and their health behaviors. Health care providers need to consider the influences of immigration transition to promote immigrant women's physical activity.

  19. Model of the physical space from quantum mechanics

    NASA Astrophysics Data System (ADS)

    Kong, Otto C. W.

    2017-08-01

    The physical world is quantum. However, our description of the quantum physics still relies much on concepts in classical physics and in some cases with ‘quantized’ interpretations. The most important case example is that of spacetime. We examine the picture of the physical space as described by simple, so-called non-relativisitic, quantum mechanics instead of assuming the Newtonian model. The key perspective is that of (relativity) symmetry representation, and the idea that the physical space is to be identified as the configuration space for a free particle. Parallel to the case of the phase space, we have a model of the quantum physical space which reduces to the Newtonian classical model under the classical limit. The latter is to be obtained as a contraction limit of the relativity symmetry.

  20. An innovation in physical modelling for testing marine renewables technology

    NASA Astrophysics Data System (ADS)

    Todd, David; Whitehouse, Richard; Harris, John; Liddiard, Mark

    2015-04-01

    HR Wallingford has undertaken physical modelling of scour around structures since its creation as a government research laboratory in 1947. Since privatisation in 1982 HR Wallingford has carried out a large number of studies for offshore developments including renewable energy developments and offshore wind in particular, looking at scour around offshore foundations and cables. To maintain our position as both a research and consultancy organisation delivering high quality work we have developed a new purpose built physical modelling facility. The Fast Flow Facility is a dual-channel, race track shaped flume and the only large scale physical modelling facility of this kind offering wave, fast tidal current and recirculating sediment capabilities. The 75 m long, 8 m wide and 2.5 m deep Fast Flow Facility has two working channels of 4 m and 2.6 m width. Holding up to a million litres of water the facility can generate waves with significant wave heights, Hs, of up to 0.5 m and maximum wave heights of up to 1 m in combination with flows of up to 2 m/s (~4 knots). This state-of-the-art facility combines fast, reversible currents with wave generation and sediment transport modelling in a single flume, allowing us to further develop our understanding of sediment transport within the marine environment and keep us at the forefront of sediment transport research. The facility has been designed with the marine renewables sector in mind, with a 4 x 4 x 1m deep sediment pit in the centre of the flume allowing investigations to provide improved understanding of the detailed processes which lead to scour, and enabling improvements in prediction capabilities for marine scour in different sediment seabed compositions (non-cohesive and cohesive) for a range of structure types (monopiles, jackets, gravity base foundations, jack-ups etc.). The facility also enables the testing of scour protection methodologies at relatively large scale (typically 1: 10 - 1:20) and allows for

  1. Investigation with respect to content and general properties of physics 11 textbook in accordance with the 2013 secondary school physics curriculum

    NASA Astrophysics Data System (ADS)

    Kavcar, Nevzat; Özen, Ali Ihsan

    2017-02-01

    Purpose of this work is to determine the physics teacher candidates' views on Physics 11 textbook' content and general properties suitable to the 2013 Secondary School Physics Curriculum. 24 teacher candidates at 2015-2016 school year constituted the sampling of the study in which scanning model based on qualitative research technique was used by performing document analysis. Data collection tool of the research was the files prepared with 51 and 28 open ended questions including the subject content and general properties of the textbook. It was concluded that the textbook was sufficient in terms of discussion, investigation, daily life context, visual elements, permanent learning traces; but was insufficient for design elements and being only one project in Electricity and Magnetism unit. Affective area activities may be involved in the textbook, there may be teacher guide book and book' teaching packet, and underline issues and qualification of the textbook may be improved.

  2. Teacher Fidelity to a Physical Education Curricular Model and Physical Activity Outcomes

    ERIC Educational Resources Information Center

    Stylianou, Michalis; Kloeppel, Tiffany; Kulinna, Pamela; van der Mars, Han

    2016-01-01

    Background: This study was informed by the bodies of literature emphasizing the role of physical education in promoting physical activity (PA) and addressing teacher fidelity to curricular models. Purpose: The purpose of this study was to compare student PA levels, lesson context, and teacher PA promotion behavior among classes where teachers were…

  3. Teacher Fidelity to a Physical Education Curricular Model and Physical Activity Outcomes

    ERIC Educational Resources Information Center

    Stylianou, Michalis; Kloeppel, Tiffany; Kulinna, Pamela; van der Mars, Han

    2016-01-01

    Background: This study was informed by the bodies of literature emphasizing the role of physical education in promoting physical activity (PA) and addressing teacher fidelity to curricular models. Purpose: The purpose of this study was to compare student PA levels, lesson context, and teacher PA promotion behavior among classes where teachers were…

  4. Frustration in model glass systems: Numerical investigations

    NASA Astrophysics Data System (ADS)

    Jullien, Rémi; Jund, Philippe; Caprion, Didier; Sadoc, Jean-François

    1999-11-01

    Numerical Voronoï tessellation is used to investigate the mechanisms of frustration in some model glass systems. First, random packings of 8192 hard spheres of increasing volume fraction c are built using an efficient computer algorithm. Their Voronoï statistics evolves with c as if the system would like to reach a pure icosahedral order when extrapolating the volume fraction above the Bernal limit cb≃0.645. Second, super-cooled liquid and glass samples of 1000 atoms are generated at different temperatures T after a quench from the liquid state, using classical micro-canonical molecular dynamics with a simple soft-sphere potential. When decreasing T, the ideal icosahedral order appears again as an extrapolated situation which cannot be realized due to geometrical frustration. Third, a model silica glass of 648 atoms is studied using the potential of van Beest, Kramer and van Santen and a quite similar quenching procedure is performed. As in the soft-sphere case the structural freezing following upon the glass transition is noticeable in all the geometrical characteristics of the Voronoï cells and again a possible interpretation in terms of geometrical frustration is proposed.

  5. Hydraulic Model Investigation: Functional Design of Control Structures for Oregon Inlet, North Carolina.

    DTIC Science & Technology

    1983-06-01

    REPORT HL-83-10 0 US-Army Corps .FUNCTIONAL DESIGN OF CONTROL STRUCTURES FOR OREGON INLET, NORTH CAROLINA Hydraulic Model Investigation TI. by Noel W...purpose of the functional model was to investigate flow control characteristics of the proposed jetty system. Important design parameters and other...above design considerations were investigated with a combina- tion fixed-bed and movable-bed physical hydraulic model molded to the bathymetry of the

  6. Physical consistency in modeling interplanetary magnetohydrodynamic fluctuations

    NASA Technical Reports Server (NTRS)

    Zhou, Y.; Matthaeus, W. H.; Roberts, D. A.; Goldstein, M. L.

    1990-01-01

    The validity of the Velli, Grappin and Mangeney (1989) model is evaluated. It is argued that the model is incorrect because it mixes different dynamical models, assumes weak nonlinearities, makes predictions that vary with observations, and violates causality. It is proposed that self-similar behavior in the coronal source region of the magnetohydrodynamic fluctuations cause the Kolmogorov-like spectra.

  7. Physical consistency in modeling interplanetary magnetohydrodynamic fluctuations

    NASA Technical Reports Server (NTRS)

    Zhou, Y.; Matthaeus, W. H.; Roberts, D. A.; Goldstein, M. L.

    1990-01-01

    The validity of the Velli, Grappin and Mangeney (1989) model is evaluated. It is argued that the model is incorrect because it mixes different dynamical models, assumes weak nonlinearities, makes predictions that vary with observations, and violates causality. It is proposed that self-similar behavior in the coronal source region of the magnetohydrodynamic fluctuations cause the Kolmogorov-like spectra.

  8. 3-D physical modeling of a complex salt canopy

    SciTech Connect

    Wiley, R.W.; Sekharan, K.K.

    1996-12-31

    Recent drilling has confirmed both significant reservoir potential and the presence of commercial hydrocarbons below salt structures in the Gulf of Mexico. Obtaining definitive seismic images with standard processing schemes beneath these salt structures is very difficult if not impossible. Because of the complicated seismic behavior of these structures, full volume 3-D prestack depth migration is required. Unfortunately, carrying out the multitude of calculations needed to create a proper image requires the largest and fastest supercomputers and rather complex numerical algorithms. Furthermore, developing and testing the imaging algorithms is quite involved and requires appropriate test data sets. To better understand the problems and issues of subsalt imaging, Marathon Oil Company and Louisiana Land and Exploration Company contracted with the University of Houston`s Allied Geophysical Laboratories (AGL) to construct a salt canopy physical model. The model is patterned after the SEG/EAEG Salt Model and is made from synthetic materials. It is a full three-dimensional model with an irregularly shaped, lateral salt structure embedded in five distinct sedimentary layers. The model was used to acquire a multi-offset 3-D marine-style survey. These data are being used to address problems of subsalt imaging. In addition to standard processing techniques, the authors investigate algorithms for multiple removal and prestack depth migration.

  9. Experimental investigations in particle physics at intermediate energies. [Physics Dept. , Temple Univ

    SciTech Connect

    Auerbach, L.B.; Highland, V.L.; McFarlane, K.W.; Kettell, S.H.

    1992-07-12

    The major emphasis of this project continues to be on fundamental symmetries and parameters of the Standard Model. A test of a quark model prediction was also done. The projects in the current period have been the following: LSND, a neutrino oscillation experiment at LAMPF; E791, a search for the decays K{sub L}{sup 0} {yields} {mu}e and K{sub L}{sup 0} {yields} ee; E871, tests and preparations for an upgrade proposal; and E888, a search for the H dibaryon. The LSND (Large Scintillator Neutrino Detector) is under construction at this time. Progress in the construction schedule has been accelerated with the expectation of being ready to accept beam in March 1993. The automated system for testing photomultiplier tubes is in full production, and should be able to certify a fun complement of tubes for installation by October 1992. Results of an earlier LAMPF experiment, E764, on the interaction of muon neutrinos with carbon nuclei have been submitted for publication. A thorough 'blind' analysis of the E791 data set has just been brought to completion. Final results for the upper limits (90% C.L.) on the branching ratios for the decays K{sub L}{sup 0} {yields} {mu}e and K{sub L}{sup 0} {yields} ee are 3.3 {times} 10{sup {minus}11} and 4.1 {times} 10{sup {minus}11}, respectively. The final result for the branching ratio for K{sub L}{sup 0} {yields} {mu}{mu} from all the data (720 events) is (7.0 {plus minus} 0.4 {plus minus} 0.2) {times} 10{sup {minus}9}. The potential of the E791 detector for rare K decays has reached its limit. Before disassembly it was used to mount a search (E888) for a possible long-lived six-quark state, the H. At the same time studies have been made of an upgraded version of the experiment (E871) that will make use of a portion of the existing apparatus.

  10. Deliberate Tracer Injections of Sulfur Hexafluoride on the West Florida Shelf in Support of: An AUV-based Investigation of the Role of Nutrient Variability in the Predictive Modeling of Physical Processes in the Littoral Ocean

    DTIC Science & Technology

    2001-09-30

    hexafluoride and it includes development of sampling methods to characterize the tracer field with high spatial and temporal resolution in near real...tracer in essence "freezes" the processes under investigation in space in this dynamic shelf region. APROACH A cruise was performed on the...hexafluoride and it includes development of sampling methods to characterize the tracer field with high spatial and temporal resolution in near real-time

  11. Models in Physics, Models for Physics Learning, and Why the Distinction may Matter in the Case of Electric Circuits

    NASA Astrophysics Data System (ADS)

    Hart, Christina

    2008-11-01

    Models are important both in the development of physics itself and in teaching physics. Historically, the consensus models of physics have come to embody particular ontological assumptions and epistemological commitments. Educators have generally assumed that the consensus models of physics, which have stood the test of time, will also work well as teaching models, and for many topics this assumption is at least unproblematic and in many cases productive. However, in the case of electric circuits the consensus models are highly abstract and consequently inaccessible to beginning learners. Certain historically derived analogues for the consensus models are accepted in texts, but these are demonstrably ineffective for helping learners grasp the fundamental concepts of electric circuits. While awareness of other models circulates informally in the teaching community, these are not well documented in the science education literature and rarely referred to in authoritative texts, possibly because the models do not share the ontological assumptions and epistemological commitments that characterise consensus models. Consequently these models have not been subjected to a disciplined critique of their effectiveness for teaching purposes. In this paper I use criteria drawn from the science education literature to reflect on why I have found particular models valuable in teaching electric circuits. These criteria contrast with the epistemological and ontological features that characterise the consensus models of science, and my reflection leads me to attend explicitly to the ways in which meanings are created within physics. This suggests that all models, whether consensus models or not, can be used more knowingly for important educational ends.

  12. Coarsening of physics for biogeochemical model in NEMO

    NASA Astrophysics Data System (ADS)

    Bricaud, Clement; Le Sommer, Julien; Madec, Gurvan; Deshayes, Julie; Chanut, Jerome; Perruche, Coralie

    2017-04-01

    Ocean mesoscale and submesoscale turbulence contribute to ocean tracer transport and to shaping ocean biogeochemical tracers distribution. Representing adequately tracer transport in ocean models therefore requires to increase model resolution so that the impact of ocean turbulence is adequately accounted for. But due to supercomputers power and storage limitations, global biogeochemical models are not yet run routinely at eddying resolution. Still, because the "effective resolution" of eddying ocean models is much coarser than the physical model grid resolution, tracer transport can be reconstructed to a large extent by computing tracer transport and diffusion with a model grid resolution close to the effective resolution of the physical model. This observation has motivated the implementation of a new capability in NEMO ocean model (http://www.nemo-ocean.eu/) that allows to run the physical model and the tracer transport model at different grid resolutions. In a first time, we present results obtained with this new capability applied to a synthetic age tracer in a global eddying model configuration. In this model configuration, ocean dynamic is computed at ¼° resolution but tracer transport is computed at 3/4° resolution. The solution obtained is compared to 2 reference setup ,one at ¼° resolution for both physics and passive tracer models and one at 3/4° resolution for both physics and passive tracer model. We discuss possible options for defining the vertical diffusivity coefficient for the tracer transport model based on information from the high resolution grid. We describe the impact of this choice on the distribution and one the penetration of the age tracer. In a second time we present results obtained by coupling the physics with the biogeochemical model PISCES. We look at the impact of this methodology on some tracers distribution and dynamic. The method described here can found applications in ocean forecasting, such as the Copernicus Marine

  13. An investigation of the physical factors controlling the sense of secondary flow circulation within submarine meanders

    NASA Astrophysics Data System (ADS)

    Darby, S. E.; Dorrell, R. M.; Peakall, J.; Sumner, E.; Parsons, D. R.; Wynn, R.

    2012-12-01

    Motivated by the symposium held at the 2011 AGU on "Submarine Channel Systems: Flow Dynamics and Sedimentary Deposits", we have undertaken a holistic investigation into the factors affecting secondary flow circulation within submarine meander bends. In both subaerial and submarine meander bends, fluid flow travels in a helical spiral, as centrifugal and hydrostatic forces balance the turbulent shear stress within the flow. Understanding the sense of the secondary flow circulation is important because the near bed orientation of the fluid flow vector strongly affects sediment transport and meander bend morphodynamic evolution, the patterns of surface grain size sorting and, ultimately it controls the character of the sedimentary deposits produced. The study we present here uses a simplified analytical model, considering the fundamental interconnectedness of the principle physical forces driving the rotational flow within submarine meanders. This holistic radial flow model, which incorporates centrifugal and Coriolis forces, the radial pressure gradient and the baroclinicity of the flow, is formulated using existing empirical models. The analytical model is validated using experimental data and used to highlight the influence of the principal physical forces acting on the flow. Previous analytical studies have considered a temporally constant, two-dimensional, rotationally invariant, framework that leads to vanishing material flux conditions when applied to flows within bounded channels. However, with reference to experimental studies, we show that a three-dimensional flow framework, with non-zero material fluxes, is required to capture the rotational structure of flow within submarine meanders. Given this three-dimensional model, we present phase-space diagrams indicating the variation of the generic vertical structure of rotational flow within submarine meanders are presented. These phase-space analyses allow a system wide discussion of secondary flow structure

  14. Relativistic models in nuclear and particle physics

    SciTech Connect

    Coester, F.

    1988-01-01

    A comparative overview is presented of different approaches to the construction of phenomenological dynamical models that respect basic principles of quantum theory and relativity. Wave functions defined as matrix elements of products of field operators on one hand and wave functions that are defined as representatives of state vectors in model Hilbert spaces are related differently to observables and dynamical models for these wave functions have each distinct advantages and disadvantages 34 refs.

  15. Flare models. [solar physics current status review

    NASA Technical Reports Server (NTRS)

    Sturrock, P. A.

    1980-01-01

    The current status of solar flare modeling is reviewed. Primary and secondary observational features that a proposed flare model should be capable of explaining are discussed, including energy storage and release, particle acceleration, mass ejection, heating of the temperature minimum region, X-ray, EUV, UV, visible and radio emission and mass flow. Consideration is then given to the twisted flux tube paramagnetic recombination model of Gold and Hoyle (1960), the current model of Alfven and Carlqvist (1967), closed current-sheet models such as those of Syrovatskii (1966, 1969, 1977) and Uchida and Sakurai (1977), open-field models such as those of Carmichael (1964) and Barnes and Sturrock (1972), the emerging flux model of Heyvaerts and Priest (1974, 1977, 1978) and the loop-flare models of Spicer (1977) and Colgate (1978). It is noted that no one model can yet account for all the observational features, and that there may turn out to be several types of flare, each requiring its own explanation.

  16. Flare models. [solar physics current status review

    NASA Technical Reports Server (NTRS)

    Sturrock, P. A.

    1980-01-01

    The current status of solar flare modeling is reviewed. Primary and secondary observational features that a proposed flare model should be capable of explaining are discussed, including energy storage and release, particle acceleration, mass ejection, heating of the temperature minimum region, X-ray, EUV, UV, visible and radio emission and mass flow. Consideration is then given to the twisted flux tube paramagnetic recombination model of Gold and Hoyle (1960), the current model of Alfven and Carlqvist (1967), closed current-sheet models such as those of Syrovatskii (1966, 1969, 1977) and Uchida and Sakurai (1977), open-field models such as those of Carmichael (1964) and Barnes and Sturrock (1972), the emerging flux model of Heyvaerts and Priest (1974, 1977, 1978) and the loop-flare models of Spicer (1977) and Colgate (1978). It is noted that no one model can yet account for all the observational features, and that there may turn out to be several types of flare, each requiring its own explanation.

  17. Searching for Physics Beyond the Standard Model

    SciTech Connect

    Catterall, Simon

    2016-12-01

    This final report summarizes the work carried out by the Syracuse component of a multi-institutional SciDAC grant led by USQCD. This grant supported software development for theoretical high energy physics. The Syracuse component specifically targeted the development of code for the numerical simulation of N=4 super Yang-Mills theory. The work described in the final report includes this and a summary of results achieve in exploring the structure of this theory. It also describes the personnel - students and a postdoc who were directly or indirectly involved in this project. A list of publication is also described.

  18. The Investigation of Physical Performance Status of Visually and Hearing Impaired Applying Judo Training Program

    ERIC Educational Resources Information Center

    Karakoc, Onder

    2016-01-01

    It was aimed to investigate the physical performances of visually and hearing impaired doing judo training in this study. 32 male athletes, who were doing judo training, volunteer and, visually and hearing impaired, participated in this study. The investigation was applied to visually impaired (N = 12, mean ± SD; age: 25.75 ± 3.55 years, height:…

  19. An Investigation into the Effectiveness of Problem-Based Learning in a Physical Chemistry Laboratory Course

    ERIC Educational Resources Information Center

    Gurses, Ahmet; Acikyildiz, Metin; Dogar, Cetin; Sozbilir, Mustafa

    2007-01-01

    The aim of this study was to investigate the effectiveness of a problem-based learning (PBL) approach in a physical chemistry laboratory course. The parameters investigated were students' attitudes towards a chemistry laboratory course, scientific process skills of students and their academic achievement. The design of the study was one group…

  20. Investigation of the Reasons of Negative Perceptions of Undergraduate Students Regarding the Modern Physics Course

    ERIC Educational Resources Information Center

    Aksakalli, Ayhan; Salar, Riza; Turgut, Umit

    2016-01-01

    In this research, the negative perceptions of undergraduate students regarding modern physics course and the causes of their negative perceptions have been investigated. For this investigation, a qualitative and quantitative method (mix method) was chosen for data collection and analysis. The study group of the research consists of a total of 169…

  1. An Investigation into the Effectiveness of Problem-Based Learning in a Physical Chemistry Laboratory Course

    ERIC Educational Resources Information Center

    Gurses, Ahmet; Acikyildiz, Metin; Dogar, Cetin; Sozbilir, Mustafa

    2007-01-01

    The aim of this study was to investigate the effectiveness of a problem-based learning (PBL) approach in a physical chemistry laboratory course. The parameters investigated were students' attitudes towards a chemistry laboratory course, scientific process skills of students and their academic achievement. The design of the study was one group…

  2. Representing Watersheds with Physics Based Distributed Hydrologic Models

    NASA Astrophysics Data System (ADS)

    Downer, C. W.; Ogden, F. L.

    2011-12-01

    Hydrologic models are useful tools for representing watershed response, helping to understand the dominant hydrologic processes in the watershed, and for estimating system response under different forcing, climatic, or physical conditions in the watershed. Model skill in predicting system response is most often demonstrated by history matching. Useful models for predicting system response under varying conditions must include the dominant processes controlling the system response. While many types of hydrologic models are capable of simulating watershed response, physics- based models are capable of simulating the actual physical conditions and responses within the watershed. There are a variety of physics-based hydrologic models available to the practicing community. Like simpler models, these models vary in formulation and complexity. Many of these models, such as the US Army of Corps of Engineers Gridded Surface Subsurface Hydrologic Analysis (GSSHA) model, allow flexibility in terms of both processes simulated and the formulation used to approximate the process. This flexibility allows the user to build the model according to his or her understanding or conceptualization, of the system, including processes that are thought to be important to system response. This also allows the user to use more rigorous methods of simulating critical processes and less rigorous methods of simulating non-critical processes or when data limitations preclude the use of more rigorous methods. In this presentation we will discuss how physics based models can, and have, been used to describe various hydrologic systems to both represent the physical processes in the system and the system response. Using examples from a variety of applications we will demonstrate and discuss the utility of utilizing a flexible physics-based model design for realizing watershed conceptualizations for hydrologic analysis.

  3. Experimental investigation of a flapping wing model

    NASA Astrophysics Data System (ADS)

    Hubel, Tatjana Y.; Tropea, Cameron

    The main objective of this research study was to investigate the aerodynamic forces of an avian flapping wing model system. The model size and the flow conditions were chosen to approximate the flight of a goose. Direct force measurements, using a three-component balance, and PIV flow field measurements parallel and perpendicular to the oncoming flow, were performed in a wind tunnel at Reynolds numbers between 28,000 and 141,000 (3-15 m/s), throughout a range of reduced frequencies between 0.04 and 0.20. The appropriateness of quasi-steady assumptions used to compare 2D, time-averaged particle image velocimetry (PIV) measurements in the wake with direct force measurements was evaluated. The vertical force coefficient for flapping wings was typically significantly higher than the maximum coefficient of the fixed wing, implying the influence of unsteady effects, such as delayed stall, even at low reduced frequencies. This puts the validity of the quasi-steady assumption into question. The (local) change in circulation over the wing beat cycle and the circulation distribution along the wingspan were obtained from the measurements in the tip and transverse vortex planes. Flow separation could be observed in the distribution of the circulation, and while the circulation derived from the wake measurements failed to agree exactly with the absolute value of the circulation, the change in circulation over the wing beat cycle was in excellent agreement for low and moderate reduced frequencies. The comparison between the PIV measurements in the two perpendicular planes and the direct force balance measurements, show that within certain limitations the wake visualization is a powerful tool to gain insight into force generation and the flow behavior on flapping wings over the wing beat cycle.

  4. Experimental investigation of a flapping wing model

    NASA Astrophysics Data System (ADS)

    Hubel, Tatjana Y.; Tropea, Cameron

    2009-05-01

    The main objective of this research study was to investigate the aerodynamic forces of an avian flapping wing model system. The model size and the flow conditions were chosen to approximate the flight of a goose. Direct force measurements, using a three-component balance, and PIV flow field measurements parallel and perpendicular to the oncoming flow, were performed in a wind tunnel at Reynolds numbers between 28,000 and 141,000 (3-15 m/s), throughout a range of reduced frequencies between 0.04 and 0.20. The appropriateness of quasi-steady assumptions used to compare 2D, time-averaged particle image velocimetry (PIV) measurements in the wake with direct force measurements was evaluated. The vertical force coefficient for flapping wings was typically significantly higher than the maximum coefficient of the fixed wing, implying the influence of unsteady effects, such as delayed stall, even at low reduced frequencies. This puts the validity of the quasi-steady assumption into question. The (local) change in circulation over the wing beat cycle and the circulation distribution along the wingspan were obtained from the measurements in the tip and transverse vortex planes. Flow separation could be observed in the distribution of the circulation, and while the circulation derived from the wake measurements failed to agree exactly with the absolute value of the circulation, the change in circulation over the wing beat cycle was in excellent agreement for low and moderate reduced frequencies. The comparison between the PIV measurements in the two perpendicular planes and the direct force balance measurements, show that within certain limitations the wake visualization is a powerful tool to gain insight into force generation and the flow behavior on flapping wings over the wing beat cycle.

  5. Investigating acetaminophen hepatotoxicity in multi-cellular organotypic liver models.

    PubMed

    Orbach, Sophia M; Cassin, Margaret E; Ehrich, Marion F; Rajagopalan, Padmavathy

    2017-08-01

    In vivo studies clearly demonstrate the participation and subsequent death of non-parenchymal liver cells (NPCs) with corresponding hepatocyte effects. This results in a critical need to investigate how major liver cell types function cohesively during hepatotoxicity. However, virtually no studies replicate these phenomena in vitro. We report the design of multi-cellular three-dimensional (3D) organotypic liver models of primary rat hepatocytes, liver sinusoidal endothelial cells (LSECs) and Kupffer cells (KCs). LSECs and KCs were separated from hepatocytes by a detachable membrane that emulates the physical and chemical properties of the Space of Disse. Acetaminophen (APAP)-induced changes to cellular function and phenotype were investigated. LSECs exhibited approximately 40% cell death at 20mM APAP. KCs exhibited decreased interleukin-10 and increased tumor necrosis factor-alpha and interferon-gamma secretion. The secretion of these proteins altered hepatocyte function and signaling. Both LSECs and KCs maintained phenotypic markers. At 20mM APAP, the 3D models exhibited aspartate aminotransferase to alanine aminotransferase ratios from 2.1-2.5 and 45% glutathione depletion, corresponding to what is seen in vivo. At 10 and 20mM APAP, the 3D models exhibited cell death, primarily through necrosis. Therefore, the 3D cultures described in this report demonstrate significant potential as realistic models for hepatotoxicity studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Investigating the Use of a Dynamic Physical Bar Chart for Data Exploration and Presentation.

    PubMed

    Taher, Faisal; Jansen, Yvonne; Woodruff, Jonathan; Hardy, John; Hornbaek, Kasper; Alexander, Jason

    2017-01-01

    Physical data representations, or data physicalizations, are a promising new medium to represent and communicate data. Previous work mostly studied passive physicalizations which require humans to perform all interactions manually. Dynamic shape-changing displays address this limitation and facilitate data exploration tasks such as sorting, navigating in data sets which exceed the fixed size of a given physical display, or preparing "views" to communicate insights about data. However, it is currently unclear how people approach and interact with such data representations. We ran an exploratory study to investigate how non-experts made use of a dynamic physical bar chart for an open-ended data exploration and presentation task. We asked 16 participants to explore a data set on European values and to prepare a short presentation of their insights using a physical display. We analyze: (1) users' body movements to understand how they approach and react to the physicalization, (2) their hand-gestures to understand how they interact with physical data, (3) system interactions to understand which subsets of the data they explored and which features they used in the process, and (4) strategies used to explore the data and present observations. We discuss the implications of our findings for the use of dynamic data physicalizations and avenues for future work.

  7. Engineered Barrier System: Physical and Chemical Environment Model

    SciTech Connect

    D. M. Jolley; R. Jarek; P. Mariner

    2004-02-09

    The conceptual and predictive models documented in this Engineered Barrier System: Physical and Chemical Environment Model report describe the evolution of the physical and chemical conditions within the waste emplacement drifts of the repository. The modeling approaches and model output data will be used in the total system performance assessment (TSPA-LA) to assess the performance of the engineered barrier system and the waste form. These models evaluate the range of potential water compositions within the emplacement drifts, resulting from the interaction of introduced materials and minerals in dust with water seeping into the drifts and with aqueous solutions forming by deliquescence of dust (as influenced by atmospheric conditions), and from thermal-hydrological-chemical (THC) processes in the drift. These models also consider the uncertainty and variability in water chemistry inside the drift and the compositions of introduced materials within the drift. This report develops and documents a set of process- and abstraction-level models that constitute the engineered barrier system: physical and chemical environment model. Where possible, these models use information directly from other process model reports as input, which promotes integration among process models used for total system performance assessment. Specific tasks and activities of modeling the physical and chemical environment are included in the technical work plan ''Technical Work Plan for: In-Drift Geochemistry Modeling'' (BSC 2004 [DIRS 166519]). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system analysis model reports.

  8. Performance results of HESP physical model

    NASA Astrophysics Data System (ADS)

    Chanumolu, Anantha; Thirupathi, Sivarani; Jones, Damien; Giridhar, Sunetra; Grobler, Deon; Jakobsson, Robert

    2017-02-01

    As a continuation to the published work on model based calibration technique with HESP(Hanle Echelle Spectrograph) as a case study, in this paper we present the performance results of the technique. We also describe how the open parameters were chosen in the model for optimization, the glass data accuracy and handling the discrepancies. It is observed through simulations that the discrepancies in glass data can be identified but not quantifiable. So having an accurate glass data is important which is possible to obtain from the glass manufacturers. The model's performance in various aspects is presented using the ThAr calibration frames from HESP during its pre-shipment tests. Accuracy of model predictions and its wave length calibration comparison with conventional empirical fitting, the behaviour of open parameters in optimization, model's ability to track instrumental drifts in the spectrum and the double fibres performance were discussed. It is observed that the optimized model is able to predict to a high accuracy the drifts in the spectrum from environmental fluctuations. It is also observed that the pattern in the spectral drifts across the 2D spectrum which vary from image to image is predictable with the optimized model. We will also discuss the possible science cases where the model can contribute.

  9. Quantum-like Probabilistic Models Outside Physics

    NASA Astrophysics Data System (ADS)

    Khrennikov, Andrei

    We present a quantum-like (QL) model in that contexts (complexes of e.g. mental, social, biological, economic or even political conditions) are represented by complex probability amplitudes. This approach gives the possibility to apply the mathematical quantum formalism to probabilities induced in any domain of science. In our model quantum randomness appears not as irreducible randomness (as it is commonly accepted in conventional quantum mechanics, e.g. by von Neumann and Dirac), but as a consequence of obtaining incomplete information about a system. We pay main attention to the QL description of processing of incomplete information. Our QL model can be useful in cognitive, social and political sciences as well as economics and artificial intelligence. In this paper we consider in a more detail one special application — QL modeling of brain's functioning. The brain is modeled as a QL-computer.

  10. Chewing simulation with a physically accurate deformable model.

    PubMed

    Pascale, Andra Maria; Ruge, Sebastian; Hauth, Steffen; Kordaß, Bernd; Linsen, Lars

    2015-01-01

    Nowadays, CAD/CAM software is being used to compute the optimal shape and position of a new tooth model meant for a patient. With this possible future application in mind, we present in this article an independent and stand-alone interactive application that simulates the human chewing process and the deformation it produces in the food substrate. Chewing motion sensors are used to produce an accurate representation of the jaw movement. The substrate is represented by a deformable elastic model based on the finite linear elements method, which preserves physical accuracy. Collision detection based on spatial partitioning is used to calculate the forces that are acting on the deformable model. Based on the calculated information, geometry elements are added to the scene to enhance the information available for the user. The goal of the simulation is to present a complete scene to the dentist, highlighting the points where the teeth came into contact with the substrate and giving information about how much force acted at these points, which therefore makes it possible to indicate whether the tooth is being used incorrectly in the mastication process. Real-time interactivity is desired and achieved within limits, depending on the complexity of the employed geometric models. The presented simulation is a first step towards the overall project goal of interactively optimizing tooth position and shape under the investigation of a virtual chewing process using real patient data (Fig 1).

  11. Investigation of physical processes in CAMILA Hall thruster using electrical probes

    NASA Astrophysics Data System (ADS)

    Kronhaus, Igal; Kapulkin, Alexander; Balabanov, Vladimir; Rubanovich, Maksim; Guelman, Moshe; Natan, Benveniste

    2012-05-01

    The CAMILA (co-axial magneto-isolated longitudinal anode) concept was developed to improve the anode efficiency in low-power Hall thrusters. Previous measurements, performed in Asher Space Research Institute, have shown that the thruster has the highest efficiency for its class. This paper presents an analysis of the discharge structure in an effort to improve understanding of the physical processes in CAMILA type thrusters. Internal measurements of the discharge parameters were performed using an emissive probe, a biased probe and a Faraday cup. The probes were mounted on a positioning system capable of mapping the channel in two dimensions. Maps for the plasma potential, the ion current density and the electron temperature were obtained. In addition, a one-dimensional fluid model was developed in order to compute the distribution of the plasma density and the ion velocity. The experimental investigations confirmed the basic assumptions used in the physical model of the CAMILA concept and revealed phenomena related to the radial non-uniformity of the discharge. In particular, focusing equipotentials were discovered in the area of intense ionization, reducing ion loss to the walls of the channel. This mechanism is principal in obtaining the high efficiency of the thruster. When operated with strengthened longitudinal magnetic field, the plasma density inside the anode cavity was significantly higher in the middle than near the anodes. The fraction of ion current generated inside the anode cavity was greater than in the simplified case, 19% compared with 13% respectively. In addition, it was shown that electrons in the cusp region, the region between predominately radial to predominately axial magnetic fields, were not well confined, however, no potential hump is created and ions are able to cross this region to the acceleration channel.

  12. The physical model of a terraced plot: first results

    NASA Astrophysics Data System (ADS)

    Perlotto, Chiara; D'Agostino, Vincenzo; Buzzanca, Giacomo

    2017-04-01

    response have been monitored and analyzed, well corroborating the findings on the kinematics of the terrace plot. Finally, the computation of the specific Curve Number (Soil Conservation Service) of the physical model has revealed values rather large if compared with those reported in the literature. This phenomena was likely caused by the high values of the inflow discharge, the limited cross-width of the model (1 m) and the increasing compactness of the soil owing to the experiment repetition. These pioneering experiments have produced some remarkable outcomes on the important role of lag-times (runoff and groundwater) of a terraced system as well as many ideas on improving the physical model and its setting in a next investigation.

  13. A Model of Physical Performance for Occupational Tasks.

    ERIC Educational Resources Information Center

    Hogan, Joyce

    This report acknowledges the problems faced by industrial/organizational psychologists who must make personnel decisions involving physically demanding jobs. The scarcity of criterion-related validation studies and the difficulty of generalizing validity are considered, and a model of physical performance that builds on Fleishman's (1984)…

  14. Educational Value and Models-Based Practice in Physical Education

    ERIC Educational Resources Information Center

    Kirk, David

    2013-01-01

    A models-based approach has been advocated as a means of overcoming the serious limitations of the traditional approach to physical education. One of the difficulties with this approach is that physical educators have sought to use it to achieve diverse and sometimes competing educational benefits, and these wide-ranging aspirations are rarely if…

  15. Early Childhood Educators' Experience of an Alternative Physical Education Model

    ERIC Educational Resources Information Center

    Tsangaridou, Niki; Genethliou, Nicholas

    2016-01-01

    Alternative instructional and curricular models are regarded as more comprehensive and suitable approaches to providing quality physical education (Kulinna 2008; Lund and Tannehill 2010; McKenzie and Kahan 2008; Metzler 2011; Quay and Peters 2008). The purpose of this study was to describe the impact of the Early Steps Physical Education…

  16. A Model of Physical Performance for Occupational Tasks.

    ERIC Educational Resources Information Center

    Hogan, Joyce

    This report acknowledges the problems faced by industrial/organizational psychologists who must make personnel decisions involving physically demanding jobs. The scarcity of criterion-related validation studies and the difficulty of generalizing validity are considered, and a model of physical performance that builds on Fleishman's (1984)…

  17. Hidden sector DM models and Higgs physics

    SciTech Connect

    Ko, P.

    2014-06-24

    We present an extension of the standard model to dark sector with an unbroken local dark U(1){sub X} symmetry. Including various singlet portal interactions provided by the standard model Higgs, right-handed neutrinos and kinetic mixing, we show that the model can address most of phenomenological issues (inflation, neutrino mass and mixing, baryon number asymmetry, dark matter, direct/indirect dark matter searches, some scale scale puzzles of the standard collisionless cold dark matter, vacuum stability of the standard model Higgs potential, dark radiation) and be regarded as an alternative to the standard model. The Higgs signal strength is equal to one as in the standard model for unbroken U(1){sub X} case with a scalar dark matter, but it could be less than one independent of decay channels if the dark matter is a dark sector fermion or if U(1){sub X} is spontaneously broken, because of a mixing with a new neutral scalar boson in the models.

  18. The influence of instructional interactions on students’ mental models about the quantization of physical observables: a modern physics course case

    NASA Astrophysics Data System (ADS)

    Didiş Körhasan, Nilüfer; Eryılmaz, Ali; Erkoç, Şakir

    2016-01-01

    Mental models are coherently organized knowledge structures used to explain phenomena. They interact with social environments and evolve with the interaction. Lacking daily experience with phenomena, the social interaction gains much more importance. In this part of our multiphase study, we investigate how instructional interactions influenced students’ mental models about the quantization of physical observables. Class observations and interviews were analysed by studying students’ mental models constructed in a modern physics course during an academic semester. The research revealed that students’ mental models were influenced by (1) the manner of teaching, including instructional methodologies and content specific techniques used by the instructor, (2) order of the topics and familiarity with concepts, and (3) peers.

  19. A Reciprocal Effects Model of Children's Body Fat Self-Concept: Relations With Physical Self-Concept and Physical Activity.

    PubMed

    Garn, Alex C; Morin, Alexandre J S; Martin, Jeffrey; Centeio, Erin; Shen, Bo; Kulik, Noel; Somers, Cheryl; McCaughtry, Nate

    2016-06-01

    This study investigated a reciprocal effects model (REM) of children's body fat self-concept and physical self-concept, and objectively measured school physical activity at different intensities. Grade four students (N = 376; M age = 9.07, SD = .61; 55% boys) from the midwest region of the United States completed measures of physical self-concept and body fat self-concept, and wore accelerometers for three consecutive school days at the beginning and end of one school year. Findings from structural equation modeling analyses did not support reciprocal effects. However, children's body fat self-concept predicted future physical self-concept and moderate-to-vigorous physical activity (MVPA). Multigroup analyses explored the moderating role of weight status, sex, ethnicity, and sex*ethnicity within the REM. Findings supported invariance, suggesting that the observed relations were generalizable for these children across demographic groups. Links between body fat self-concept and future physical self-concept and MVPA highlight self-enhancing effects that can promote children's health and well-being.

  20. Mothers and Fathers Both Matter: The Positive Influence of Parental Physical Activity Modelling on Children's Leisure-Time Physical Activity.

    PubMed

    Schoeppe, Stephanie; Liersch, Sebastian; Röbl, Markus; Krauth, Christian; Walter, Ulla

    2016-08-01

    To investigate associations between maternal and paternal sport participation, and children's leisure-time physical activity, and to explore differences by child gender. The sample comprised 737 year five students (mean age: 11.0 ± 0.6 years, 52% male) recruited through the Fit for Pisa Project which was conducted in 2008 at 6 secondary schools in Goettingen, Germany. Maternal and paternal sport participation were assessed through child reports of mothers' and fathers' weekly participation in sport. Children's leisure-time physical activity was measured as minutes/week that children engaged in organized and nonorganized sport. Multiple linear regression was used to assess associations between maternal and paternal sport participation, and children's leisure-time physical activity. Both maternal and paternal sport participation were positively associated with children's leisure-time physical activity (maternal: b = 34.20, p < .001; paternal: b = 25.32, p < .05). When stratifying analyses by child gender, maternal sport participation remained significantly associated with leisure-time physical activity in girls (b = 60.64, p < .001). In contrast, paternal sport participation remained significantly associated with leisure-time physical activity in boys (b = 43.88, p < .01). Both maternal and paternal modeling positively influence children's leisure-time physical activity.

  1. Massive Stars: Input Physics and Stellar Models

    NASA Astrophysics Data System (ADS)

    El Eid, M. F.; The, L.-S.; Meyer, B. S.

    2009-10-01

    We present a general overview of the structure and evolution of massive stars of masses ≥12 M ⊙ during their pre-supernova stages. We think it is worth reviewing this topic owing to the crucial role of massive stars in astrophysics, especially in the evolution of galaxies and the universe. We have performed several test computations with the aim to analyze and discuss many physical uncertainties still encountered in massive-star evolution. In particular, we explore the effects of mass loss, convection, rotation, 12C( α, γ)16O reaction and initial metallicity. We also compare and analyze the similarities and differences among various works and ours. Finally, we present useful comments on the nucleosynthesis from massive stars concerning the s-process and the yields for 26Al and 60Fe.

  2. Automated Qualitative Modeling of Dynamic Physical Systems

    DTIC Science & Technology

    1993-01-01

    paths of states that match a qualitative history. DATMI differs from QSIM- CHECK in that it first constructs an envisionment of the model, a graph...containing all possible model states where an arc connects two states if one could be a successor of the other. Once it has constructed the envisionment ...DATMI is fairly efficient in finding paths through it that correspond to interpretations of the measurements. However, the number of envisionment

  3. Investigation of post hydraulic fracturing well cleanup physics in the Cana Woodford Shale

    NASA Astrophysics Data System (ADS)

    Lu, Rong

    Hydraulic fracturing was first carried out in the 1940s and has gained popularity in current development of unconventional resources. Flowing back the fracturing fluids is critical to a frac job, and determining well cleanup characteristics using the flowback data can help improve frac design. It has become increasingly important as a result of the unique flowback profiles observed in some shale gas plays due to the unconventional formation characteristics. Computer simulation is an efficient and effective way to tackle the problem. History matching can help reveal some mechanisms existent in the cleanup process. The Fracturing, Acidizing, Stimulation Technology (FAST) Consortium at Colorado School of Mines previously developed a numerical model for investigating the hydraulic fracturing process, cleanup, and relevant physics. It is a three-dimensional, gas-water, coupled fracture propagation-fluid flow simulator, which has the capability to handle commonly present damage mechanisms. The overall goal of this research effort is to validate the model on real data and to investigate the dominant physics in well cleanup for the Cana Field, which produces from the Woodford Shale in Oklahoma. To achieve this goal, first the early time delayed gas production was explained and modeled, and a simulation framework was established that included all three relevant damage mechanisms for a slickwater fractured well. Next, a series of sensitivity analysis of well cleanup to major reservoir, fracture, and operational variables was conducted; five of the Cana wells' initial flowback data were history matched, specifically the first thirty days' gas and water producing rates. Reservoir matrix permeability, net pressure, Young's modulus, and formation pressure gradient were found to have an impact on the gas producing curve's shape, in different ways. Some moderately good matches were achieved, with the outcome of some unknown reservoir information being proposed using the

  4. Investigating System Dependability Modeling Using AADL

    NASA Technical Reports Server (NTRS)

    Hall, Brendan; Driscoll, Kevin R.; Madl, Gabor

    2013-01-01

    This report describes Architecture Analysis & Design Language (AADL) models for a diverse set of fault-tolerant, embedded data networks and describes the methods and tools used to created these models. It also includes error models per the AADL Error Annex. Some networks were modeled using Error Detection Isolation Containment Types (EDICT). This report gives a brief description for each of the networks, a description of its modeling, the model itself, and evaluations of the tools used for creating the models. The methodology includes a naming convention that supports a systematic way to enumerate all of the potential failure modes.

  5. Propulsion Physics Under the Changing Density Field Model

    NASA Technical Reports Server (NTRS)

    Robertson, Glen A.

    2011-01-01

    To grow as a space faring race, future spaceflight systems will requires new propulsion physics. Specifically a propulsion physics model that does not require mass ejection without limiting the high thrust necessary to accelerate within or beyond our solar system and return within a normal work period or lifetime. In 2004 Khoury and Weltman produced a density dependent cosmology theory they called Chameleon Cosmology, as at its nature, it is hidden within known physics. This theory represents a scalar field within and about an object, even in the vacuum. Whereby, these scalar fields can be viewed as vacuum energy fields with definable densities that permeate all matter; having implications to dark matter/energy with universe acceleration properties; implying a new force mechanism for propulsion physics. Using Chameleon Cosmology, the author has developed a new propulsion physics model, called the Changing Density Field (CDF) Model. This model relates to density changes in these density fields, where the density field density changes are related to the acceleration of matter within an object. These density changes in turn change how an object couples to the surrounding density fields. Whereby, thrust is achieved by causing a differential in the coupling to these density fields about an object. Since the model indicates that the density of the density field in an object can be changed by internal mass acceleration, even without exhausting mass, the CDF model implies a new propellant-less propulsion physics model

  6. A Physically Based Coupled Chemical and Physical Weathering Model for Simulating Soilscape Evolution

    NASA Astrophysics Data System (ADS)

    Willgoose, G. R.; Welivitiya, D.; Hancock, G. R.

    2015-12-01

    A critical missing link in existing landscape evolution models is a dynamic soil evolution models where soils co-evolve with the landform. Work by the authors over the last decade has demonstrated a computationally manageable model for soil profile evolution (soilscape evolution) based on physical weathering. For chemical weathering it is clear that full geochemistry models such as CrunchFlow and PHREEQC are too computationally intensive to be couplable to existing soilscape and landscape evolution models. This paper presents a simplification of CrunchFlow chemistry and physics that makes the task feasible, and generalises it for hillslope geomorphology applications. Results from this simplified model will be compared with field data for soil pedogenesis. Other researchers have previously proposed a number of very simple weathering functions (e.g. exponential, humped, reverse exponential) as conceptual models of the in-profile weathering process. The paper will show that all of these functions are possible for specific combinations of in-soil environmental, geochemical and geologic conditions, and the presentation will outline the key variables controlling which of these conceptual models can be realistic models of in-profile processes and under what conditions. The presentation will finish by discussing the coupling of this model with a physical weathering model, and will show sample results from our SSSPAM soilscape evolution model to illustrate the implications of including chemical weathering in the soilscape evolution model.

  7. Comparing the Hydrologic and Watershed Processes between a Full Scale Stochastic Model Versus a Scaled Physical Model of Bell Canyon

    NASA Astrophysics Data System (ADS)

    Hernandez, K. F.; Shah-Fairbank, S.

    2016-12-01

    The San Dimas Experimental Forest has been designated as a research area by the United States Forest Service for use as a hydrologic testing facility since 1933 to investigate watershed hydrology of the 27 square mile land. Incorporation of a computer model provides validity to the testing of the physical model. This study focuses on San Dimas Experimental Forest's Bell Canyon, one of the triad of watersheds contained within the Big Dalton watershed of the San Dimas Experimental Forest. A scaled physical model was constructed of Bell Canyon to highlight watershed characteristics and each's effect on runoff. The physical model offers a comprehensive visualization of a natural watershed and can vary the characteristics of rainfall intensity, slope, and roughness through interchangeable parts and adjustments to the system. The scaled physical model is validated and calibrated through a HEC-HMS model to assure similitude of the system. Preliminary results of the physical model suggest that a 50-year storm event can be represented by a peak discharge of 2.2 X 10-3 cfs. When comparing the results to HEC-HMS, this equates to a flow relationship of approximately 1:160,000, which can be used to model other return periods. The completion of the Bell Canyon physical model can be used for educational instruction in the classroom, outreach in the community, and further research using the model as an accurate representation of the watershed present in the San Dimas Experimental Forest.

  8. Distances in spaces of physical models: partition functions versus spectra

    NASA Astrophysics Data System (ADS)

    Cornelissen, Gunther; Kontogeorgis, Aristides

    2017-01-01

    We study the relation between convergence of partition functions (seen as general Dirichlet series) and convergence of spectra and their multiplicities. We describe applications to convergence in physical models, e.g., related to topology change and averaging in cosmology.

  9. Transfer of Learning: From Physical Models to Understanding Complex Phenomena*

    NASA Astrophysics Data System (ADS)

    Aryal, Bijaya; Zollman, D. A.

    2006-12-01

    This study describes the student associations made in order to understand the application of physics to a medical imaging technology positron emission tomography. We define this association as the transfer of learning. The physical models, which have a functional resemblance to portions of the positron emission tomography (PET) process, were introduced to the students without any mention of PET during a teaching session. After a hiatus of a few days they attended another session where PET was briefly mentioned to them. Immediately after that they were asked questions that involved the application of physics ideas underlying the model to describe the PET process. Results of this study indicate that physical models are useful in this transfer of learning. We also observed facilitation in transferring ideas from the models to the problem through peer interaction. *Supported by the National Science Foundation under grant 04-2675.

  10. A hybrid (numerical-physical) model of the left ventricle.

    PubMed

    Ferrari, G; Kozarski, M; De Lazzari, C; Clemente, F; Merolli, M; Tosti, G; Guaragno, M; Mimmo, R; Ambrosi, D; Glapinski, J

    2001-07-01

    Hydraulic models of the circulation are used to test mechanical devices and for training and research purposes; when compared to numerical models, however, they are not flexible enough and rather expensive. The solution proposed here is to merge the characteristics and the flexibility of numerical models with the functions of physical models. The result is a hybrid model with numerical and physical sections connected by an electro-hydraulic interface - which is to some extent the main problem since the numerical model can be easily changed or modified. The concept of hybrid model is applied to the representation of ventricular function by a variable elastance numerical model. This prototype is an open loop circuit and the physical section is built out of a reservoir (atrium) and a modified windkessel (arterial tree). The corresponding equations are solved numerically using the variables (atrial and arterial pressures) coming from the physical circuit. Ventricular output flow is the computed variable and is sent to a servo amplifier connected to a DC motor-gear pump system. The gear pump, behaving roughly as a flow source, is the interface to the physical circuit. Results obtained under different hemodynamic conditions demonstrate the behaviour of the ventricular model on the pressure-volume plane and the time course of output flow and arterial pressure.

  11. Evaluation and development of physically-based embankment breach models

    USDA-ARS?s Scientific Manuscript database

    The CEATI Dam Safety Interest Group (DSIG) working group on embankment erosion and breach modelling has evaluated three physically-based numerical models used to simulate embankment erosion and breach development. The three models identified by the group were considered to be good candidates for fu...

  12. Evaluation and development of physically-based embankment breach models

    USDA-ARS?s Scientific Manuscript database

    The CEATI Dam Safety Interest Group (DSIG) working group on embankment erosion and breach modelling has evaluated three physically-based numerical models used to simulate embankment erosion and breach development. The three models identified by the group were considered to be good candidates for fu...

  13. Harmony Theory: Problem Solving, Parallel Cognitive Models, and Thermal Physics.

    ERIC Educational Resources Information Center

    Smolensky, Paul; Riley, Mary S.

    This document consists of three papers. The first, "A Parallel Model of (Sequential) Problem Solving," describes a parallel model designed to solve a class of relatively simple problems from elementary physics and discusses implications for models of problem-solving in general. It is shown that one of the most salient features of problem…

  14. Harmony Theory: Problem Solving, Parallel Cognitive Models, and Thermal Physics.

    ERIC Educational Resources Information Center

    Smolensky, Paul; Riley, Mary S.

    This document consists of three papers. The first, "A Parallel Model of (Sequential) Problem Solving," describes a parallel model designed to solve a class of relatively simple problems from elementary physics and discusses implications for models of problem-solving in general. It is shown that one of the most salient features of problem…

  15. Kinetic exchange models: From molecular physics to social science

    NASA Astrophysics Data System (ADS)

    Patriarca, Marco; Chakraborti, Anirban

    2013-08-01

    We discuss several multi-agent models that have their origin in the kinetic exchange theory of statistical mechanics and have been recently applied to a variety of problems in the social sciences. This class of models can be easily adapted for simulations in areas other than physics, such as the modeling of income and wealth distributions in economics and opinion dynamics in sociology.

  16. An Expectancy-Value Model for Sustained Enrolment Intentions of Senior Secondary Physics Students

    NASA Astrophysics Data System (ADS)

    Abraham, Jessy; Barker, Katrina

    2015-08-01

    This study investigates the predictive influences of achievement motivational variables that may sustain students' engagement in physics and influence their future enrolment plans in the subject. Unlike most studies attempting to address the decline of physics enrolments through capturing students' intention to enrol in physics before ever studying the subject, this study is novel because it captures the perceptions of students currently enrolled in senior secondary physics and their subsequent enrolment intentions after completing modules from the physics curriculum. Participants comprised of senior secondary students in year 11 completing their first year of physics in Australia across nine high schools in New South Wales. The Sustained Enrolment Models for Physics (SEMP), which drew upon the Expectancy-Value (EV) theoretical foundation, proposed predictive relations among students' achievement motivation, sustained engagement, and enrolment intentions in relation to physics. The data showed a good fit to the theoretically developed model for all four physics topics from the year 11 curriculum. The path coefficients of the models demonstrated the strength of relationships among the variables for each of the topics. The topic specificity of SEMPs allowed the mapping of students' motivational patterns at a more sensitive level than the domain-specific level and suggested that the relative influence of motivational precursors can vary by topic. This study advanced the EV research knowledge that, while values may be significant, it is the expectancies that largely predict students' sustained choice intentions in relation to physics. Implications for these findings are discussed.

  17. Numerical investigation of algebraic oceanic turbulent mixing-layer models

    NASA Astrophysics Data System (ADS)

    Chacón-Rebollo, T.; Gómez-Mármol, M.; Rubino, S.

    2013-11-01

    In this paper we investigate the finite-time and asymptotic behaviour of algebraic turbulent mixing-layer models by numerical simulation. We compare the performances given by three different settings of the eddy viscosity. We consider Richardson number-based vertical eddy viscosity models. Two of these are classical algebraic turbulence models usually used in numerical simulations of global oceanic circulation, i.e. the Pacanowski-Philander and the Gent models, while the other one is a more recent model (Bennis et al., 2010) proposed to prevent numerical instabilities generated by physically unstable configurations. The numerical schemes are based on the standard finite element method. We perform some numerical tests for relatively large deviations of realistic initial conditions provided by the Tropical Atmosphere Ocean (TAO) array. These initial conditions correspond to states close to mixing-layer profiles, measured on the Equatorial Pacific region called the West-Pacific Warm Pool. We conclude that mixing-layer profiles could be considered as kinds of "absorbing configurations" in finite time that asymptotically evolve to steady states under the application of negative surface energy fluxes.

  18. A physical model of Titan's aerosols

    NASA Technical Reports Server (NTRS)

    Toon, O. B.; Mckay, C. P.; Griffith, C. A.; Turco, R. P.

    1992-01-01

    A modeling effort is presented for the nature of the stratospheric haze on Titan, under several simplifying assumptions; chief among these is that the aerosols in question are of a single composition, and involatile. It is further assumed that a one-dimensional model is capable of simulating the general characteristics of the aerosol. It is suggested in this light that the detached haze on Titan may be a manifestation of organized, Hadley-type motions above 300 km altitude, with vertical velocities of 1 cm/sec. The hemispherical asymmetry of the visible albedo may be due to organized vertical motions within the upper 150-200 km of the haze.

  19. ITER physics-safety interface: models and assessments

    SciTech Connect

    Uckan, N.A.; Putvinski, S.; Wesley, J.; Bartels, H-W.; Honda, T.; Amano, T.; Boucher, D.; Fujisawa, N.; Post, D.; Rosenbluth, M.

    1996-10-01

    Plasma operation conditions and physics requirements to be used as a basis for safety analysis studies are developed and physics results motivated by safety considerations are presented for the ITER design. Physics guidelines and specifications for enveloping plasma dynamic events for Category I (operational event), Category II (likely event), and Category III (unlikely event) are characterized. Safety related physics areas that are considered are: (i) effect of plasma on machined and safety (disruptions, runaway electrons, fast plasma shutdown) and (ii) plasma response to ex-vessel LOCA from first wall providing a potential passive plasma shutdown due to Be evaporation. Physics models and expressions developed are implemented in safety analysis code (SAFALY, couples 0-D dynamic plasma model to thermal response of the in-vessel components). Results from SAFALY are presented.

  20. Using the Bifocal Modeling Framework to Resolve "Discrepant Events" Between Physical Experiments and Virtual Models in Biology

    NASA Astrophysics Data System (ADS)

    Blikstein, Paulo; Fuhrmann, Tamar; Salehi, Shima

    2016-08-01

    In this paper, we investigate an approach to supporting students' learning in science through a combination of physical experimentation and virtual modeling. We present a study that utilizes a scientific inquiry framework, which we call "bifocal modeling," to link student-designed experiments and computer models in real time. In this study, a group of high school students designed computer models of bacterial growth with reference to a simultaneous physical experiment they were conducting, and were able to validate the correctness of their model against the results of their experiment. Our findings suggest that as the students compared their virtual models with physical experiments, they encountered "discrepant events" that contradicted their existing conceptions and elicited a state of cognitive disequilibrium. This experience of conflict encouraged students to further examine their ideas and to seek more accurate explanations of the observed natural phenomena, improving the design of their computer models.

  1. A physical model of sensorimotor interactions during locomotion

    NASA Astrophysics Data System (ADS)

    Klein, Theresa J.; Lewis, M. Anthony

    2012-08-01

    In this paper, we describe the development of a bipedal robot that models the neuromuscular architecture of human walking. The body is based on principles derived from human muscular architecture, using muscles on straps to mimic agonist/antagonist muscle action as well as bifunctional muscles. Load sensors in the straps model Golgi tendon organs. The neural architecture is a central pattern generator (CPG) composed of a half-center oscillator combined with phase-modulated reflexes that is simulated using a spiking neural network. We show that the interaction between the reflex system, body dynamics and CPG results in a walking cycle that is entrained to the dynamics of the system. We also show that the CPG helped stabilize the gait against perturbations relative to a purely reflexive system, and compared the joint trajectories to human walking data. This robot represents a complete physical, or ‘neurorobotic’, model of the system, demonstrating the usefulness of this type of robotics research for investigating the neurophysiological processes underlying walking in humans and animals.

  2. Investigating how students think about and learn quantum physics: An example from tunneling

    NASA Astrophysics Data System (ADS)

    Morgan, Jeffrey T.

    Much of physics education research (PER) has focused on introductory courses and topics, with less research done into how students learn physics in advanced courses. Members of The University of Maine Physics Education Research Laboratory (PERL) have begun studying how students in advanced physics courses reason about classical mechanics, thermal physics, and quantum physics. Here, we describe an investigation into how students reason about quantum mechanical tunneling, and detail how those findings informed a portion of a curriculum development project. Quantum mechanical tunneling is a standard topic discussed in most modern physics and quantum physics courses. Understanding tunneling is crucial to making sense of several topics in physics, including scanning tunneling microscopy and nuclear decay. To make sense of the standard presentation of tunneling, students must track total, potential, and kinetic energies. Additionally, they must distinguish between the ideas of energy, probability density, and the wave function. They need to understand the complex nature of the wave function, as well as understand what can and cannot be inferred from a solution to the time-independent Schrodinger equation. Our investigations into student understanding of these ideas consisted of a series of interviews, as well as a survey. Both centered around asking students to reason about energy, probability, and the wave function solutions for the standard square potential energy barrier scenario presented in most textbooks. We describe ideas that students seem to successfully learn following standard instruction, as well as common difficulties that remain. Additionally, we present multiple data points from a small population of physics majors over three years and describe how some of their reasoning about tunneling changed, while other portions seemed to remain unaffected by instruction. We used the results of these investigations to write tutorials on tunneling and applications of

  3. Investigating children's spiritual experiences through the Health and Physical Education (HPE) learning area in Australian schools.

    PubMed

    Lynch, Timothy

    2015-02-01

    The purpose of this study is to explore spirituality within the Health and Physical Education (HPE) learning area, through investigating children's experiences within three Brisbane Catholic Education primary schools (Queensland, Australia). There are seven dimensions of wellness: physical, intellectual, emotional, social, spiritual, environmental, and occupational, which are all strongly connected (Robbins et al. in A wellness way of life, 9th edition, McGraw Hill, USA, 2011). It is logical that HPE, which promotes students to adopt lifelong health and well-being, offers opportunities for spirituality to be experienced and warrants investigation. Data gathered in this qualitative research suggest that regular quality inclusive HPE lessons increased students' potential for spiritual experiences.

  4. Validation and upgrading of physically based mathematical models

    NASA Technical Reports Server (NTRS)

    Duval, Ronald

    1992-01-01

    The validation of the results of physically-based mathematical models against experimental results was discussed. Systematic techniques are used for: (1) isolating subsets of the simulator mathematical model and comparing the response of each subset to its experimental response for the same input conditions; (2) evaluating the response error to determine whether it is the result of incorrect parameter values, incorrect structure of the model subset, or unmodeled external effects of cross coupling; and (3) modifying and upgrading the model and its parameter values to determine the most physically appropriate combination of changes.

  5. Methodology Investigation of Software Maturity Model Validation

    DTIC Science & Technology

    1989-11-13

    Cassondra Renfro provided helpful coments in the review of the report. I SEcTON 1. SUMALR 1.1 BACIRUND. Software h~s become a major part of Comuand...example, is that each software fault that is discovered is either corrected or not counted again. Brooks and Motley’s Models, on the other hand, assume...Between Error Occurrence ERROR COUNT MODELS 1 The Generalized Poisson Model 2 The Non - Homogeneous Poisson Model 3 The Brooks and Motley Model 4 The

  6. Characterizing, modeling, and addressing gender disparities in introductory college physics

    NASA Astrophysics Data System (ADS)

    Kost-Smith, Lauren Elizabeth

    2011-12-01

    The underrepresentation and underperformance of females in physics has been well documented and has long concerned policy-makers, educators, and the physics community. In this thesis, we focus on gender disparities in the first- and second-semester introductory, calculus-based physics courses at the University of Colorado. Success in these courses is critical for future study and careers in physics (and other sciences). Using data gathered from roughly 10,000 undergraduate students, we identify and model gender differences in the introductory physics courses in three areas: student performance, retention, and psychological factors. We observe gender differences on several measures in the introductory physics courses: females are less likely to take a high school physics course than males and have lower standardized mathematics test scores; males outscore females on both pre- and post-course conceptual physics surveys and in-class exams; and males have more expert-like attitudes and beliefs about physics than females. These background differences of males and females account for 60% to 70% of the gender gap that we observe on a post-course survey of conceptual physics understanding. In analyzing underlying psychological factors of learning, we find that female students report lower self-confidence related to succeeding in the introductory courses (self-efficacy) and are less likely to report seeing themselves as a "physics person". Students' self-efficacy beliefs are significant predictors of their performance, even when measures of physics and mathematics background are controlled, and account for an additional 10% of the gender gap. Informed by results from these studies, we implemented and tested a psychological, self-affirmation intervention aimed at enhancing female students' performance in Physics 1. Self-affirmation reduced the gender gap in performance on both in-class exams and the post-course conceptual physics survey. Further, the benefit of the self

  7. Investigating the productivity model for clinical nurses.

    PubMed

    Dehghan Nayeri, Nahid; Hooshmand Bahabadi, Abbas; Kazemnejad, Anoshirvan

    2014-01-01

    One of the main objectives of quantitative researches is assessment of models developed by qualitative studies. Models validation through their testing implies that the designed model is representative of the existed facts. Hence, this study was conducted to assess the clinical nurses' productivity model presented for Iranian nurses' productivity. The sample of the study consisted of 360 nurses of Tehran University of Medical Sciences. The research tool was a questionnaire for measuring the components of clinical nurses' productivity. After completing all steps of instrument psychometric and getting answers from the participants, the factors introduced in the questionnaire were named and then Lisrel Path Analysis tests were performed to analyze the components of the model. The results of the model test revealed there is an internal relationship among different components of the model. Regression Analysis showed that each increasing unit in components of the model was to be added to central variable of productivity model -human resource. Model components altogether explained 20 % of clinical nurses' productivity variance. This study found that the important component of productivity is human resources that are reciprocally related to other components of the model. Therefore, it can be stated that the managers can promote the productivity by using efficient strategies to correct human resource patterns.

  8. The Physics of the Vicsek model

    NASA Astrophysics Data System (ADS)

    Ginelli, Francesco

    2016-11-01

    In these lecture notes, prepared for the Microswimmers Summer School 2015 at Forschungszentrum Jülich, I discuss the well known Vicsek model for collective motion and its main properties. In particular, I discuss its algorithmic implementation and the basic properties of its universality class. I present results from numerical simulations and insist on the role played by symmetries and conservation laws. Analytical arguments are presented in an accessible and simplified way, but ample references are given for more advanced readings.

  9. Atomistic Model of Physical Ageing in Se-rich As-Se Glasses

    SciTech Connect

    Golovchak,R.; Shpotyuk, O.; Kozdras, A.; Bureau, B.; Vlcek, M.; Ganjoo, A.; Jain, H.

    2007-01-01

    Thermal, optical, X-ray excited and magnetic methods were used to develop a microstructural model of physical ageing in Se-rich glasses. The glass composition As10Se90, possessing a typical cross-linked chain structure, was chosen as a model object for the investigations. The effect of physical ageing in this glass was revealed by differential scanning calorimetry, whereas the corresponding changes in its atomic arrangement were studied by extended X-ray absorption fine structure, Raman and solid-state 77Se nuclear magnetic resonance spectroscopy. Straightening-shrinkage processes are shown to be responsible for the physical ageing in this Se-rich As-Se glass.

  10. Beyond standard model physics at current and future colliders

    NASA Astrophysics Data System (ADS)

    Liu, Zhen

    The Large Hadron Collider (LHC), a multinational experiment which began running in 2009, is highly expected to discover new physics that will help us understand the nature of the universe and begin to find solutions to many of the unsolved puzzles of particle physics. For over 40 years the Standard Model has been the accepted theory of elementary particle physics, except for one unconfirmed component, the Higgs boson. The experiments at the LHC have recently discovered this Standard-Model-like Higgs boson. This discovery is one of the most exciting achievements in elementary particle physics. Yet, a profound question remains: Is this rather light, weakly-coupled boson nothing but a Standard Model Higgs or a first manifestation of a deeper theory? Also, the recent discoveries of neutrino mass and mixing, experimental evidences of dark matter and dark energy, matter-antimatter asymmetry, indicate that our understanding of fundamental physics is currently incomplete. For the next decade and more, the LHC and future colliders will be at the cutting-edge of particle physics discoveries and will shed light on many of these unanswered questions. There are many promising beyond-Standard-Model theories that may help solve the central puzzles of particle physics. To fill the gaps in our knowledge, we need to know how these theories will manifest themselves in controlled experiments, such as high energy colliders. I discuss how we can probe fundamental physics at current and future colliders directly through searches for new phenomena such as resonances, rare Higgs decays, exotic displaced signatures, and indirectly through precision measurements on Higgs in this work. I explore beyond standard model physics effects from different perspectives, including explicit models such as supersymmetry, generic models in terms of resonances, as well as effective field theory approach in terms of higher dimensional operators. This work provides a generic and broad overview of the physics

  11. Physical activity and lung cancer risk in the European Prospective Investigation into Cancer and Nutrition Cohort.

    PubMed

    Steindorf, Karen; Friedenreich, Christine; Linseisen, Jakob; Rohrmann, Sabine; Rundle, Andrew; Veglia, Fabrizio; Vineis, Paolo; Johnsen, Nina Fønns; Tjønneland, Anne; Overvad, Kim; Raaschou-Nielsen, Ole; Clavel-Chapelon, Françoise; Boutron-Ruault, Marie-Christine; Schulz, Mandy; Boeing, Heiner; Trichopoulou, Antonia; Kalapothaki, Victoria; Koliva, Maria; Krogh, Vittorio; Palli, Domenico; Tumino, Rosario; Panico, Salvatore; Monninkhof, Evelyn; Peeters, Petra H; Boshuizen, Hendriek C; Bueno-de-Mesquita, H Bas; Chirlaque, Maria-Dolores; Agudo, Antonio; Larrañaga, Nerea; Quirós, José R; Martínez, Carmen; Barricarte, Aurelio; Janzon, Lars; Berglund, Göran; Bingham, Sheila; Khaw, Kay-Tee; Key, Timothy J; Norat, Teresa; Jenab, Mazda; Cust, Anne; Riboli, Elio

    2006-11-15

    Research conducted predominantly in male populations on physical activity and lung cancer has yielded inconsistent results. We examined this relationship among 416,277 men and women from the European Prospective Investigation into Cancer and Nutrition (EPIC). Detailed information on recent recreational, household and occupational physical activity, smoking habits and diet was assessed at baseline between 1992 and 2000. Relative risks (RR) were estimated using Cox regression. During 6.3 years of follow-up we identified 607 men and 476 women with incident lung cancer. We did not observe an inverse association between recent occupational, recreational or household physical activity and lung cancer risk in either males or females. However, we found some reduction in lung cancer risk associated with sports in males (adjusted RR = 0.71; 95% confidence interval 0.50-0.98; highest tertile vs. inactive group), cycling (RR = 0.73; 0.54-0.99) in females and non-occupational vigorous physical activity. For occupational physical activity, lung cancer risk was increased for unemployed men (adjusted RR = 1.57; 1.20-2.05) and men with standing occupations (RR = 1.35; 1.02-1.79) compared with sitting professions. There was no evidence of heterogeneity of physical activity associations across countries, or across any of the considered cofactors. For some histologic subtypes suggestive sex-specific reductions, limited by subgroup sizes, were observed, especially with vigorous physical activity. In total, our study shows no consistent protective associations of physical activity with lung cancer risk. It can be assumed that the elevated risks found for occupational physical activity are not produced mechanistically by physical activity itself but rather reflect exposure to occupation-related lung cancer risk factors.

  12. Dark matter physics, flavor physics and LHC constraints in the dark matter model with a bottom partner

    NASA Astrophysics Data System (ADS)

    Abe, Tomohiro; Kawamura, Junichiro; Okawa, Shohei; Omura, Yuji

    2017-03-01

    In the scenario that dark matter (DM) is a weakly interacting massive particle, there are many possibilities of the interactions with the Standard Model (SM) particles to achieve the relic density of DM. In this paper, we consider a simple DM model where the DM candidate is a complex scalar boson. The model contains a new complex gauge singlet scalar boson and a new fermion whose gauge charge is the same as the right-handed down-type quark. We dub the new fermion the bottom partner. These new particles have Yukawa interactions with the SM down-type quarks. The DM candidate interacts with the SM particles through the Yukawa interactions. The Yukawa interactions are not only relevant to the annihilation process of the DM but also contribute to the flavor physics, such as the Δ F = 2 processes. In addition, the flavor alignment of the Yukawa couplings is related to the decay modes of the bottom partner, and thus we can find the explicit correlations among the physical observables in DM physics, flavor physics, and the signals at the LHC. We survey the Δ F = 2 processes based on the numerical analyses of the thermal relic density, the direct detection of the DM, and the current LHC bounds. We investigate the perturbative bound on the Yukawa coupling as well. A Study of a fermionic DM model with extra scalar quarks is also given for comparison.

  13. Application of physical parameter identification to finite element models

    NASA Technical Reports Server (NTRS)

    Bronowicki, Allen J.; Lukich, Michael S.; Kuritz, Steven P.

    1986-01-01

    A time domain technique for matching response predictions of a structural dynamic model to test measurements is developed. Significance is attached to prior estimates of physical model parameters and to experimental data. The Bayesian estimation procedure allows confidence levels in predicted physical and modal parameters to be obtained. Structural optimization procedures are employed to minimize an error functional with physical model parameters describing the finite element model as design variables. The number of complete FEM analyses are reduced using approximation concepts, including the recently developed convoluted Taylor series approach. The error function is represented in closed form by converting free decay test data to a time series model using Prony' method. The technique is demonstrated on simulated response of a simple truss structure.

  14. Multiperspective-Modelling in the Process of Constructing and Understanding Physical Theories Using the Example of the Plane Mirror Image

    NASA Astrophysics Data System (ADS)

    Böhm, U.; Pospiech, G.; Körndle, H.; Narciss, S.

    2010-07-01

    Teaching physics goes along with explaining natural phenomena. The modelling process during the acquisition of physical knowledge plays an important role in developing understanding and deeper insight. Novices, however, have problems with this modelling process, in particular because they do not understand that teachers are talking about models of reality and not about reality itself. Physical theories are described with linguistic and mathematical symbols; hence there exist at least two perspectives of modelling, physical and mathematical modelling. According to Greca and Moreira (2001) [2] understanding of physics in school is achieved if it is possible to predict a physical phenomenon from its physical models. Yet, apart from the physical and the mathematical perspective of modelling other perspectives of modelling are necessary for understanding complex physical phenomena. To prevent confusion for the learner it is essential to differentiate between these different perspectives of modelling. This process of differentiation between various perspectives of modelling will be referred to as `Multiperspective-Modelling'. Prior studies (F. Goldberg and L. McDermott, (1986), Wiesner 1992) [1, 5] on how individual students think about images in plane mirrors revealed that the learners have misconceptions. Based on the idea of `Multiperspective-Modelling' we developed and evaluated a special training for the learner. This training differentiates physical, mathematical and `human' perspectives of modelling of the plane mirror phenomenon. The purposes of this study were to investigate the understanding of the plane mirror phenomenon of novices, before and after the special training.

  15. The limitations of mathematical modeling in high school physics education

    NASA Astrophysics Data System (ADS)

    Forjan, Matej

    The theme of the doctoral dissertation falls within the scope of didactics of physics. Theoretical analysis of the key constraints that occur in the transmission of mathematical modeling of dynamical systems into field of physics education in secondary schools is presented. In an effort to explore the extent to which current physics education promotes understanding of models and modeling, we analyze the curriculum and the three most commonly used textbooks for high school physics. We focus primarily on the representation of the various stages of modeling in the solved tasks in textbooks and on the presentation of certain simplifications and idealizations, which are in high school physics frequently used. We show that one of the textbooks in most cases fairly and reasonably presents the simplifications, while the other two half of the analyzed simplifications do not explain. It also turns out that the vast majority of solved tasks in all the textbooks do not explicitly represent model assumptions based on what we can conclude that in high school physics the students do not develop sufficiently a sense of simplification and idealizations, which is a key part of the conceptual phase of modeling. For the introduction of modeling of dynamical systems the knowledge of students is also important, therefore we performed an empirical study on the extent to which high school students are able to understand the time evolution of some dynamical systems in the field of physics. The research results show the students have a very weak understanding of the dynamics of systems in which the feedbacks are present. This is independent of the year or final grade in physics and mathematics. When modeling dynamical systems in high school physics we also encounter the limitations which result from the lack of mathematical knowledge of students, because they don't know how analytically solve the differential equations. We show that when dealing with one-dimensional dynamical systems

  16. Sediment dynamics in the Adriatic Sea investigated with coupled models

    USGS Publications Warehouse

    Sherwood, Christopher R.; Book, Jeffrey W.; Carniel, Sandro; Cavaleri, Luigi; Chiggiato, Jacopo; Das, Himangshu; Doyle, James D.; Harris, Courtney K.; Niedoroda, Alan W.; Perkins, Henry; Poulain, Pierre-Marie; Pullen, Julie; Reed, Christopher W.; Russo, Aniello; Sclavo, Mauro; Signell, Richard P.; Traykovski, Peter A.; Warner, John C.

    2004-01-01

    Several large research programs focused on the Adriatic Sea in winter 2002-2003, making it an exciting place for sediment dynamics modelers (Figure 1). Investigations of atmospheric forcing and oceanic response (including wave generation and propagation, water-mass formation, stratification, and circulation), suspended material, bottom boundary layer dynamics, bottom sediment, and small-scale stratigraphy were performed by European and North American researchers participating in several projects. The goal of EuroSTRATAFORM researchers is to improve our ability to understand and simulate the physical processes that deliver sediment to the marine environment and generate stratigraphic signatures. Scientists involved in the Po and Apennine Sediment Transport and Accumulation (PASTA) experiment benefited from other major research programs including ACE (Adriatic Circulation Experiment), DOLCE VITA (Dynamics of Localized Currents and Eddy Variability in the Adriatic), EACE (the Croatian East Adriatic Circulation Experiment project), WISE (West Istria Experiment), and ADRICOSM (Italian nowcasting and forecasting) studies.

  17. A GLOBAL PHYSICAL MODEL FOR CEPHEIDS

    SciTech Connect

    Pejcha, Ondrej; Kochanek, Christopher S. E-mail: ckochanek@astronomy.ohio-state.edu

    2012-04-01

    We perform a global fit to {approx}5000 radial velocity and {approx}177, 000 magnitude measurements in 29 photometric bands covering 0.3 {mu}m to 8.0 {mu}m distributed among 287 Galactic, Large Magellanic Cloud, and Small Magellanic Cloud Cepheids with P > 10 days. We assume that the Cepheid light curves and radial velocities are fully characterized by distance, reddening, and time-dependent radius and temperature variations. We construct phase curves of radius and temperature for periods between 10 and 100 days, which yield light-curve templates for all our photometric bands and can be easily generalized to any additional band. With only four to six parameters per Cepheid, depending on the existence of velocity data and the amount of freedom in the distance, the models have typical rms light and velocity curve residuals of 0.05 mag and 3.5 km s{sup -1}. The model derives the mean Cepheid spectral energy distribution and its derivative with respect to temperature, which deviate from a blackbody in agreement with metal-line and molecular opacity effects. We determine a mean reddening law toward the Cepheids in our sample, which is not consistent with standard assumptions in either the optical or near-IR. Based on stellar atmosphere models, we predict the biases in distance, reddening, and temperature determinations due to the metallicity and quantify the metallicity signature expected for our fit residuals. The observed residuals as a function of wavelength show clear differences between the individual galaxies, which are compatible with these predictions. In particular, we find that metal-poor Cepheids appear hotter. Finally, we provide a framework for optimally selecting filters that yield the smallest overall errors in Cepheid parameter determination or filter combinations for suppressing or enhancing the metallicity effects on distance determinations. We make our templates publicly available.

  18. An Investigation of Human Performance Model Validation

    DTIC Science & Technology

    2005-03-01

    from both models and empirical activities, and the construction of scenarios that will sufficiently exercise model and human participants. 1 Development...Soar to represent peripheral players/platforms in simulation-based exercises that are used to evaluate system design concepts and tactics.) We expect...and operational concepts can best be employed to assist them." As noted above, models used in the JSB exercise must be highly accurate and accredited

  19. Numerical and measured data from the 3D salt canopy physical modeling project

    SciTech Connect

    Bradley, C.; House, L.; Fehler, M.; Pearson, J.; TenCate, J.; Wiley, R.

    1997-11-01

    The evolution of salt structures in the Gulf of Mexico have been shown to provide a mechanism for the trapping of significant hydrocarbon reserves. Most of these structures have complex geometries relative to the surrounding sedimentary layers. This aspect in addition to high velocities within the salt tend to scatter and defocus seismic energy and make imaging of subsalt lithology extremely difficult. An ongoing program the SEG/EAEG modeling project (Aminzadeh et al. 1994a: Aminzadeh et al. 1994b: Aminzadeh et al. 1995), and a follow-up project funded as part of the Advanced Computational Technology Initiative (ACTI) (House et al. 1996) have sought to investigate problems with imaging beneath complex salt structures using numerical modeling and more recently, construction of a physical model patterned after the numerical subsalt model (Wiley and McKnight. 1996). To date, no direct comparison of the numerical and physical aspects of these models has been attempted. We present the results of forward modeling a numerical realization of the 3D salt canopy physical model with the French Petroleum Institute (IFP) acoustic finite difference algorithm used in the numerical subsalt tests. We compare the results from the physical salt canopy model, the acoustic modeling of the physical/numerical model and the original numerical SEG/EAEG Salt Model. We will be testing the sensitivity of migration to the presence of converted shear waves and acquisition geometry.

  20. Physics beyond the Standard Model from hydrogen spectroscopy

    NASA Astrophysics Data System (ADS)

    Ubachs, W.; Koelemeij, J. C. J.; Eikema, K. S. E.; Salumbides, E. J.

    2016-02-01

    Spectroscopy of hydrogen can be used for a search into physics beyond the Standard Model. Differences between the absorption spectra of the Lyman and Werner bands of H2 as observed at high redshift and those measured in the laboratory can be interpreted in terms of possible variations of the proton-electron mass ratio μ =mp /me over cosmological history. Investigation of ten such absorbers in the redshift range z = 2.0 -4.2 yields a constraint of | Δμ / μ | < 5 ×10-6 at 3σ. Observation of H2 from the photospheres of white dwarf stars inside our Galaxy delivers a constraint of similar magnitude on a dependence of μ on a gravitational potential 104 times as strong as on the Earth's surface. While such astronomical studies aim at finding quintessence in an indirect manner, laboratory precision measurements target such additional quantum fields in a direct manner. Laser-based precision measurements of dissociation energies, vibrational splittings and rotational level energies in H2 molecules and their deuterated isotopomers HD and D2 produce values for the rovibrational binding energies fully consistent with quantum ab initio calculations including relativistic and quantum electrodynamical (QED) effects. Similarly, precision measurements of high-overtone vibrational transitions of HD+ ions, captured in ion traps and sympathetically cooled to mK temperatures, also result in transition frequencies fully consistent with calculations including QED corrections. Precision measurements of inter-Rydberg transitions in H2 can be extrapolated to yield accurate values for level splittings in the H2+ -ion. These comprehensive results of laboratory precision measurements on neutral and ionic hydrogen molecules can be interpreted to set bounds on the existence of possible fifth forces and of higher dimensions, phenomena describing physics beyond the Standard Model.

  1. Physics based modeling and control of reactive extrusion

    NASA Astrophysics Data System (ADS)

    Elkouss, Paul F.

    2004-11-01

    Kinematic modeling has been shown to be important for the understanding and control of co-rotating twin screw extruders. The residence time distribution (RTD) is often used to characterize the steady-state behavior of an extrusion process. Due to the complex rheological behavior of polymer flow in the extruder, few have felt that the RTD would be independent of changes in operating conditions for the same screw configuration. To investigate, we are asserting that resident distributions could be independent of operating conditions for certain types of polymers. Four different polymers, two polyethylenes and two polypropylenes, were processed on the same 30mm Werner and Pfleiderer co-rotating twin-screw extruder (CoTSE) equipped with reflectance optical probes to compare their RTD's. Additionally, each material was tested to determine its complex viscosity, to better understand the phenomena involved. Using physically motivated models to control reactive extrusion processes is attractive because of the flexibility and robustness it could provide. This thesis uses residence distribution analyses to characterize the material flow through a co-rotating twin-screw extruder. Furthermore, we examine the applicability of residence distributions as the basis for kinematic modeling of the extrusion process. This demonstration of using a steady-state model---the residence distribution---as a basis for kinematic behavior is unique. The signals have been deconvoluted to kinematically characterize the flow in the different regions of the extruder, such as the melting, mixing and metering zones. Studies of step changes have shown that the steady state value of extrudate viscosity is dependent on the peroxide concentration, volume mixing, and on the residence time from the specific throughput. This data has also provided plant models of the peroxide initiated degradation reaction using system identification techniques. Although a specific example of vis-breaking of polypropylene is

  2. Physics-based lithium ion silver vanadium oxide cathode model

    NASA Astrophysics Data System (ADS)

    Strange, Derek A.; Rayman, Sean; Shaffer, Jesse S.; White, Ralph E.

    A cathode half cell physics-based model for a St. Jude Medical fabricated silver vanadium oxide (SVO) cathode coin cell battery was constructed. The model is based on a single particle Fick's second law approach with the open-circuit potential modeled with a Redlich-Kister equation. By assuming that lithium ions intercalate only through the ends of the cuboid SVO particles, the model is able to predict accurately the discharge profile of experimental cathode half cell coin cells.

  3. "Let's get physical": advantages of a physical model over 3D computer models and textbooks in learning imaging anatomy.

    PubMed

    Preece, Daniel; Williams, Sarah B; Lam, Richard; Weller, Renate

    2013-01-01

    Three-dimensional (3D) information plays an important part in medical and veterinary education. Appreciating complex 3D spatial relationships requires a strong foundational understanding of anatomy and mental 3D visualization skills. Novel learning resources have been introduced to anatomy training to achieve this. Objective evaluation of their comparative efficacies remains scarce in the literature. This study developed and evaluated the use of a physical model in demonstrating the complex spatial relationships of the equine foot. It was hypothesized that the newly developed physical model would be more effective for students to learn magnetic resonance imaging (MRI) anatomy of the foot than textbooks or computer-based 3D models. Third year veterinary medicine students were randomly assigned to one of three teaching aid groups (physical model; textbooks; 3D computer model). The comparative efficacies of the three teaching aids were assessed through students' abilities to identify anatomical structures on MR images. Overall mean MRI assessment scores were significantly higher in students utilizing the physical model (86.39%) compared with students using textbooks (62.61%) and the 3D computer model (63.68%) (P < 0.001), with no significant difference between the textbook and 3D computer model groups (P = 0.685). Student feedback was also more positive in the physical model group compared with both the textbook and 3D computer model groups. Our results suggest that physical models may hold a significant advantage over alternative learning resources in enhancing visuospatial and 3D understanding of complex anatomical architecture, and that 3D computer models have significant limitations with regards to 3D learning. © 2013 American Association of Anatomists.

  4. Investigation of the Endochronic Concrete Model.

    DTIC Science & Technology

    1983-05-01

    involved. The adequacy of future system design and analysis therefore depends on the development of advanced material models for reinforced concrete...a C slight strength gain for the experimental data. The model produces an exag- gerated strength gain, probably as a result of the accumulation of

  5. Investigation of Thermal Creep and Thermal Stress Effects in Microgravity Physical Vapor Transport

    NASA Technical Reports Server (NTRS)

    Mackowski, D. W. (Principal Investigator); Knight, R. W. (Principal Investigator)

    1996-01-01

    Reported here are the results of our numerical investigation into the mechanisms which affect the transport and growth processes in physical vapor transport (PVT) crystal growth ampoules. The first part of the report consists of a brief summary of the major accomplishments and conclusions of our work. The second part consists of two manuscripts, submitted to the Journal of Crystal Growth, which provided a detailed description of the findings in our investigation.

  6. Applying Transtheoretical Model to Promote Physical Activities Among Women

    PubMed Central

    Pirzadeh, Asiyeh; Mostafavi, Firoozeh; Ghofranipour, Fazllolah; Feizi, Awat

    2015-01-01

    Background: Physical activity is one of the most important indicators of health in communities but different studies conducted in the provinces of Iran showed that inactivity is prevalent, especially among women. Objectives: Inadequate regular physical activities among women, the importance of education in promoting the physical activities, and lack of studies on the women using transtheoretical model, persuaded us to conduct this study with the aim of determining the application of transtheoretical model in promoting the physical activities among women of Isfahan. Materials and Methods: This research was a quasi-experimental study which was conducted on 141 women residing in Isfahan, Iran. They were randomly divided into case and control groups. In addition to the demographic information, their physical activities and the constructs of the transtheoretical model (stages of change, processes of change, decisional balance, and self-efficacy) were measured at 3 time points; preintervention, 3 months, and 6 months after intervention. Finally, the obtained data were analyzed through t test and repeated measures ANOVA test using SPSS version 16. Results: The results showed that education based on the transtheoretical model significantly increased physical activities in 2 aspects of intensive physical activities and walking, in the case group over the time. Also, a high percentage of people have shown progress during the stages of change, the mean of the constructs of processes of change, as well as pros and cons. On the whole, a significant difference was observed over the time in the case group (P < 0.01). Conclusions: This study showed that interventions based on the transtheoretical model can promote the physical activity behavior among women. PMID:26834796

  7. Applying Transtheoretical Model to Promote Physical Activities Among Women.

    PubMed

    Pirzadeh, Asiyeh; Mostafavi, Firoozeh; Ghofranipour, Fazllolah; Feizi, Awat

    2015-12-01

    Physical activity is one of the most important indicators of health in communities but different studies conducted in the provinces of Iran showed that inactivity is prevalent, especially among women. Inadequate regular physical activities among women, the importance of education in promoting the physical activities, and lack of studies on the women using transtheoretical model, persuaded us to conduct this study with the aim of determining the application of transtheoretical model in promoting the physical activities among women of Isfahan. This research was a quasi-experimental study which was conducted on 141 women residing in Isfahan, Iran. They were randomly divided into case and control groups. In addition to the demographic information, their physical activities and the constructs of the transtheoretical model (stages of change, processes of change, decisional balance, and self-efficacy) were measured at 3 time points; preintervention, 3 months, and 6 months after intervention. Finally, the obtained data were analyzed through t test and repeated measures ANOVA test using SPSS version 16. The results showed that education based on the transtheoretical model significantly increased physical activities in 2 aspects of intensive physical activities and walking, in the case group over the time. Also, a high percentage of people have shown progress during the stages of change, the mean of the constructs of processes of change, as well as pros and cons. On the whole, a significant difference was observed over the time in the case group (P < 0.01). This study showed that interventions based on the transtheoretical model can promote the physical activity behavior among women.

  8. Animal models in the investigation of anorexia.

    PubMed

    Siegfried, Zahava; Berry, Elliot M; Hao, Shuzhen; Avraham, Yosefa

    2003-06-01

    Anorexia nervosa (AN) is an eating disorder of unknown origin that most commonly occurs in women and usually has its onset in adolescence. Patients with AN invariably have a disturbed body image and an intense fear of weight gain. There is currently no definitive treatment for this disease, which carries a 20% mortality over 20 years. Development of an appropriate animal model of AN has been difficult, as the etiology of this eating disorder likely involves a complex interaction between genetic, environmental, social, and cultural factors. In this review, we focus on several possible rodent models of AN. In our laboratory, we have developed and studied three different mouse models of AN based on clinical profiles of the disease; separation stress, activity, and diet restriction (DR). In addition, we discuss the spontaneous mouse mutation anx/anx and several mouse gene knockout models, which have resulted in an anorexic phenotype. We highlight what has been learned from each of these models and possibilities for future models. It is hoped that a combination of the study of such models, together with genetic and clinical studies in patients, will lead to more rational and successful prevention/treatment of this tragic, and often fatal, disease.

  9. Investigating Middle School Students' Ability to Develop Energy as a Framework for Analyzing Simple Physical Phenomena

    ERIC Educational Resources Information Center

    Papadouris, Nicos; Constantinou, Constantinos P.

    2016-01-01

    We investigated whether it is possible for 12-year-old students to develop a qualitative conceptualization of energy and four associate features (forms of energy, transfer processes, conservation, and degradation) as a framework for constructing interpretive accounts for the operation of physical phenomena (specifically, for changes taking place…

  10. The Investigation of the Relation between Physical Activity and Academic Success

    ERIC Educational Resources Information Center

    Iri, Ruchan; Ibis, Serkan; Aktug, Zait Burak

    2017-01-01

    The purpose of the study is to investigate the interaction among Physical Activity Levels (PAL), academic successes, perceived academic competency and Motor Skills (MS) of male and female students at the age of 14-17 in terms of gender variable. The PALs, perceived academic competency and academic successes were determined through International…

  11. An Investigation of the Self-Regulation Components Students Employ in the Physical Education Setting

    ERIC Educational Resources Information Center

    Kermarrec, Gilles; Todorovich, John; Fleming, David

    2004-01-01

    Research in educational psychology and sport psychology indicates that school achievement depends on students' capacity to self-regulate their own learning processes. The purpose of this study was to investigate the self-regulation components employed by students in a natural physical education setting. Twenty-three French students, 14 and 15…

  12. An Investigation of Students' Embodied Discourses in Physical Education: A Gender Project

    ERIC Educational Resources Information Center

    Azzarito, Laura; Solmon, Melinda

    2009-01-01

    Despite significant theoretical and practical progress over the past 20 years, the social construction of gender and its link to youths' participation in physical activity in school contexts remain critical issues that call for further socioeducational scrutiny. In this study, researchers investigated the ways students' embodiment of discursive…

  13. PE on YouTube--Investigating Participation in Physical Education Practice

    ERIC Educational Resources Information Center

    Quennerstedt, Mikael

    2013-01-01

    Background: In this article, students' diverse ways of participating in physical education (PE) practice shown in clips on YouTube were investigated. YouTube is the largest user-generated video-sharing website on the Internet, where different video content is presented. The clips on YouTube, as used in this paper, can be seen as a user-generated…

  14. Investigating Factors in the Retention of Students in High School Physical Education

    ERIC Educational Resources Information Center

    Lodewyk, Ken R.; Pybus, Colin M.

    2013-01-01

    Several studies have reported declining student enrolment rates in optional physical education. This study--incorporating constructs from social cognitive, self-determination, and body image theory--investigated factors that might be influential to this trend. Surveys were administered to 227 tenth-grade students from five schools in one school…

  15. Investigation of Professional Self Sufficiency Levels of Physical Education and Sports Teachers

    ERIC Educational Resources Information Center

    Saracaoglu, Asuman Seda; Ozsaker, Murat; Varol, Rana

    2012-01-01

    The present research aimed at detecting professional self sufficiency levels of physical education and sports teachers who worked in Izmir Province and at investigating them in terms of some variables. For data collection, Teacher's Sense of Efficacy Scale-developed by Moran and Woolfolk-Hoy (2001) and Turkish validity and reliability studies…

  16. Investigating Middle School Students' Ability to Develop Energy as a Framework for Analyzing Simple Physical Phenomena

    ERIC Educational Resources Information Center

    Papadouris, Nicos; Constantinou, Constantinos P.

    2016-01-01

    We investigated whether it is possible for 12-year-old students to develop a qualitative conceptualization of energy and four associate features (forms of energy, transfer processes, conservation, and degradation) as a framework for constructing interpretive accounts for the operation of physical phenomena (specifically, for changes taking place…

  17. Spin-foam models and the physical scalar product

    SciTech Connect

    Alesci, Emanuele; Noui, Karim; Sardelli, Francesco

    2008-11-15

    This paper aims at clarifying the link between loop quantum gravity and spin-foam models in four dimensions. Starting from the canonical framework, we construct an operator P acting on the space of cylindrical functions Cyl({gamma}), where {gamma} is the four-simplex graph, such that its matrix elements are, up to some normalization factors, the vertex amplitude of spin-foam models. The spin-foam models we are considering are the topological model, the Barrett-Crane model, and the Engle-Pereira-Rovelli model. If one of these spin-foam models provides a covariant quantization of gravity, then the associated operator P should be the so-called ''projector'' into physical states and its matrix elements should give the physical scalar product. We discuss the possibility to extend the action of P to any cylindrical functions on the space manifold.

  18. Simple universal models capture all classical spin physics.

    PubMed

    De las Cuevas, Gemma; Cubitt, Toby S

    2016-03-11

    Spin models are used in many studies of complex systems because they exhibit rich macroscopic behavior despite their microscopic simplicity. Here, we prove that all the physics of every classical spin model is reproduced in the low-energy sector of certain "universal models," with at most polynomial overhead. This holds for classical models with discrete or continuous degrees of freedom. We prove necessary and sufficient conditions for a spin model to be universal and show that one of the simplest and most widely studied spin models, the two-dimensional Ising model with fields, is universal. Our results may facilitate physical simulations of Hamiltonians with complex interactions. Copyright © 2016, American Association for the Advancement of Science.

  19. Technical Manual for the SAM Physical Trough Model

    SciTech Connect

    Wagner, M. J.; Gilman, P.

    2011-06-01

    NREL, in conjunction with Sandia National Lab and the U.S Department of Energy, developed the System Advisor Model (SAM) analysis tool for renewable energy system performance and economic analysis. This paper documents the technical background and engineering formulation for one of SAM's two parabolic trough system models in SAM. The Physical Trough model calculates performance relationships based on physical first principles where possible, allowing the modeler to predict electricity production for a wider range of component geometries than is possible in the Empirical Trough model. This document describes the major parabolic trough plant subsystems in detail including the solar field, power block, thermal storage, piping, auxiliary heating, and control systems. This model makes use of both existing subsystem performance modeling approaches, and new approaches developed specifically for SAM.

  20. Applying Socioecological Model to Improve Women’s Physical Activity: A Randomized Control Trial

    PubMed Central

    Tehrani, Hadi; Majlessi, Fershteh; Shojaeizadeh, Davoud; Sadeghi, Roya; Hasani Kabootarkhani, Marzieh

    2016-01-01

    Background: A sedentary life without sufficient physical activity is recognized as a risk factor for various diseases, and a major modifiable risk factor for noncommunicable diseases. This study was conducted to investigate the effect of intervention using socioecological model in promoting women’s physical activity in the city of Kerman, Iran. Materials and Methods: In this randomized, double-blinded, controlled study, 360 women were studied at health and medical centers of Kerman. This educational intervention was based on socioecological model and conducted on 4 levels of personal, social, organizational, and political. Data collection tool included a researcher-made questionnaire based on constructs of socioecological model and the international physical activity inventory. Results: The results indicated insignificant differences between the two groups in terms of perceived social, physical, and political support and also with regard to level of physical activity before intervention. However after the intervention and according to independent t test, significant differences were observed between two groups in perceived social, physical, and political support and also level of physical activity (P < 0.001). Furthermore, mean values of the above terms increased in the intervention group. Conclusions: According to the results, interventions based on socioecological model can positively affect women’s physical activity. PMID:27247781

  1. Model Rocketry in the 21st-Century Physics Classroom

    NASA Astrophysics Data System (ADS)

    Horst, Ken

    2004-10-01

    Model rocketry has changed since my introduction to it as an eighth-grade student. Two of these changes are important for the use of rocketry in the physics classroom. First, simulation software, which is relatively inexpensive and very powerful, allows students to create and fly virtual models of their rocket designs. Second, lightweight and sophisticated electronics2 are available for logging flight data and for controlling flight operations such as deploying parachutes. In this technology-rich context, designing, building, and flying model rockets can capture the interest of today's physics students.

  2. Investigating the Place and Meaning of "Physical Education" to Preschool Children: Methodological Lessons from a Research Study

    ERIC Educational Resources Information Center

    McEvilly, Nollaig

    2015-01-01

    Preschool physical education has not been extensively researched. Furthermore, research in physical activity and physical education rarely seeks young children's perspectives. The current paper focuses on one aspect of a post-structural study concerned with investigating the place and meaning of "physical education" to practitioners and…

  3. Investigating the Place and Meaning of "Physical Education" to Preschool Children: Methodological Lessons from a Research Study

    ERIC Educational Resources Information Center

    McEvilly, Nollaig

    2015-01-01

    Preschool physical education has not been extensively researched. Furthermore, research in physical activity and physical education rarely seeks young children's perspectives. The current paper focuses on one aspect of a post-structural study concerned with investigating the place and meaning of "physical education" to practitioners and…

  4. Rock.XML - Towards a library of rock physics models

    NASA Astrophysics Data System (ADS)

    Jensen, Erling Hugo; Hauge, Ragnar; Ulvmoen, Marit; Johansen, Tor Arne; Drottning, Åsmund

    2016-08-01

    Rock physics modelling provides tools for correlating physical properties of rocks and their constituents to the geophysical observations we measure on a larger scale. Many different theoretical and empirical models exist, to cover the range of different types of rocks. However, upon reviewing these, we see that they are all built around a few main concepts. Based on this observation, we propose a format for digitally storing the specifications for rock physics models which we have named Rock.XML. It does not only contain data about the various constituents, but also the theories and how they are used to combine these building blocks to make a representative model for a particular rock. The format is based on the Extensible Markup Language XML, making it flexible enough to handle complex models as well as scalable towards extending it with new theories and models. This technology has great advantages as far as documenting and exchanging models in an unambiguous way between people and between software. Rock.XML can become a platform for creating a library of rock physics models; making them more accessible to everyone.

  5. Physical Models of Galaxy Formation in a Cosmological Framework

    NASA Astrophysics Data System (ADS)

    Somerville, Rachel S.; Davé, Romeel

    2015-08-01

    Modeling galaxy formation in a cosmological context presents one of the greatest challenges in astrophysics today due to the vast range of scales and numerous physical processes involved. Here we review the current status of models that employ two leading techniques to simulate the physics of galaxy formation: semianalytic models and numerical hydrodynamic simulations. We focus on a set of observational targets that describe the evolution of the global and structural properties of galaxies from roughly cosmic high noon (z â¼ 2-3) to the present. Although minor discrepancies remain, overall, models show remarkable convergence among different methods and make predictions that are in qualitative agreement with observations. Modelers have converged on a core set of physical processes that are critical for shaping galaxy properties. This core set includes cosmological accretion, strong stellar-driven winds that are more efficient at low masses, black hole feedback that preferentially suppresses star formation at high masses, and structural and morphological evolution through merging and environmental processes. However, all cosmological models currently adopt phenomenological implementations of many of these core processes, which must be tuned to observations. Many details of how these diverse processes interact within a hierarchical structure formation setting remain poorly understood. Emerging multiscale simulations are helping to bridge the gap between stellar and cosmological scales, placing models on a firmer, more physically grounded footing. Concurrently, upcoming telescope facilities will provide new challenges and constraints for models, particularly by directly constraining inflows and outflows through observations of gas in and around galaxies.

  6. Partial Possible Models: An Approach To Interpret Students' Physical Representation.

    ERIC Educational Resources Information Center

    Camacho, Fernando Flores; Cazares, Leticia Gallegos

    1998-01-01

    Illustrates the construction of conceptual models on pressure and flotation using high school students' previous ideas on these concepts. Identifies three models and uses them to analyze students' ideas about physical phenomena and to recognize the inferential structure they use. Contains 28 references. (DDR)

  7. A simple physical model for forest fire spread

    Treesearch

    E. Koo; P. Pagni; J. Woycheese; S. Stephens; D. Weise; J. Huff

    2005-01-01

    Based on energy conservation and detailed heat transfer mechanisms, a simple physical model for fire spread is presented for the limit of one-dimensional steady-state contiguous spread of a line fire in a thermally-thin uniform porous fuel bed. The solution for the fire spread rate is found as an eigenvalue from this model with appropriate boundary conditions through a...

  8. Snyder-de Sitter model from two-time physics

    SciTech Connect

    Carrisi, M. C.; Mignemi, S.

    2010-11-15

    We show that the symplectic structure of the Snyder model on a de Sitter background can be derived from two-time physics in seven dimensions and propose a Hamiltonian for a free particle consistent with the symmetries of the model.

  9. Model Checking the FlexRay Physical Layer Protocol

    NASA Astrophysics Data System (ADS)

    Gerke, Michael; Ehlers, Rüdiger; Finkbeiner, Bernd; Peter, Hans-Jörg

    The FlexRay standard, developed by a cooperation of leading companies in the automotive industry, is a robust communication protocol for distributed components in modern vehicles. In this paper, we present the first timed automata model of its physical layer protocol, and we use automatic verification to prove fault tolerance under several error models and hardware assumptions.

  10. A physically based analytical spatial air temperature and humidity model

    Treesearch

    Yang Yang; Theodore A. Endreny; David J. Nowak

    2013-01-01

    Spatial variation of urban surface air temperature and humidity influences human thermal comfort, the settling rate of atmospheric pollutants, and plant physiology and growth. Given the lack of observations, we developed a Physically based Analytical Spatial Air Temperature and Humidity (PASATH) model. The PASATH model calculates spatial solar radiation and heat...

  11. Beyond Standard Model Physics: At the Frontiers of Cosmology and Particle Physics

    NASA Astrophysics Data System (ADS)

    Lopez-Suarez, Alejandro O.

    I begin to write this thesis at a time of great excitement in the field of cosmology and particle physics. The aim of this thesis is to study and search for beyond the standard model (BSM) physics in the cosmological and high energy particle fields. There are two main questions, which this thesis aims to address: 1) what can we learn about the inflationary epoch utilizing the pioneer gravitational wave detector Adv. LIGO?, and 2) what are the dark matter particle properties and interactions with the standard model particles?. This thesis will focus on advances in answering both questions.

  12. The relation between student motivation and student grades in physical education: A 3-year investigation.

    PubMed

    Barkoukis, V; Taylor, I; Chanal, J; Ntoumanis, N

    2014-10-01

    Enhancing students' academic engagement is the key element of the educational process; hence, research in this area has focused on understanding the mechanisms that can lead to increased academic engagement. The present study investigated the relation between motivation and grades in physical education (PE) employing a 3-year longitudinal design. Three hundred fifty-four Greek high school students participated in the study. Students completed measures of motivation to participate in PE on six occasions; namely, at the start and the end of the school year in the first, second, and third year of junior high school. Students' PE grades were also recorded at these time points. The results of the multilevel growth models indicated that students' PE grades increased over the 3 years and students had better PE grades at the end of each year than at the beginning of the subsequent year. In general, students and classes with higher levels of controlling motivation achieved lower PE grades, whereas higher levels of autonomous motivation were associated with higher PE grades. These findings provide new insight on the associations between class- and individual-level motivation with objectively assessed achievement in PE. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. THE MEGAMASER COSMOLOGY PROJECT. VII. INVESTIGATING DISK PHYSICS USING SPECTRAL MONITORING OBSERVATIONS

    SciTech Connect

    Pesce, D. W.; Braatz, J. A.; Condon, J. J.; Gao, F.; Lo, K. Y.; Henkel, C.; Litzinger, E.; Reid, M. J.

    2015-09-01

    We use single-dish radio spectra of known 22 GHz H{sub 2}O megamasers, primarily gathered from the large data set observed by the Megamaser Cosmology Project, to identify Keplerian accretion disks and to investigate several aspects of the disk physics. We test a mechanism for maser excitation proposed by Maoz and McKee (1998), whereby population inversion arises in gas behind spiral shocks traveling through the disk. Though the flux of redshifted features is larger on average than that of blueshifted features, in support of the model, the high-velocity features show none of the predicted systematic velocity drifts. We find rapid intra-day variability in the maser spectrum of ESO 558−G009 that is likely the result of interstellar scintillation, for which we favor a nearby (D ≈ 70 pc) scattering screen. In a search for reverberation in six well-sampled sources, we find that any radially propagating signal must be contributing ≲10% of the total variability. We also set limits on the magnetic field strengths in seven sources, using strong flaring events to check for the presence of Zeeman splitting. These limits are typically 200–300 mG (1σ), but our most stringent limits reach down to 73 mG for the galaxy NGC 1194.

  14. Investigating the physical basis of river memory and application to flood frequency prediction

    NASA Astrophysics Data System (ADS)

    Iliopoulou, Theano; Aguilar, Christina; Arheimer, Berit; Bermúdez, María; Bezak, Nejc; Ficchi, Andrea; Koutsoyiannis, Demetris; Parajka, Juraj; José Polo, María; Thirel, Guillaume; Montanari, Alberto

    2017-04-01

    We investigate the long memory properties of 224 european rivers spanning more than 50 years of daily flow data. For this purpose, we identify two periods of interest; High Flow Seasons (HFS) as 3-month periods receiving the maximum occurrences of peaks-over-threshold flows and Dry Months (DM) as 1-month periods with the minimum average flow. We compute the lagged seasonal correlation for the peak flows in the HFS and the average flows in the DM both against the average flows in the antecedent months. The HFS and DM correlations are compared in terms of magnitude and variability and both are linked to geophysical river characteristics, e.g. basin size and baseflow index along with various site-specific catchment controls (e.g. lakes, glaciers etc.). Through a Meta-Gaussian data assimilation approach, we explore the benefit from conditioning the peak flow distribution in the HFS upon observance of a higher-than-usual (e.g. 95th quantile) flow in the pre-HFS month. To this end, the estimated correlation between the peak flows in HFS and average flows in the pre-HFS month is employed in fitting a bivariate Meta-Gaussian probability distribution model. The benefit of the suggested approach is showcased by updating the flood frequency distribution in real-world applications. Our findings suggest that river memory has a prominent physical basis and a high technical relevance in the case of seasonal flood frequency prediction.

  15. The Megamaser Cosmology Project. VII. Investigating Disk Physics Using Spectral Monitoring Observations

    NASA Astrophysics Data System (ADS)

    Pesce, D. W.; Braatz, J. A.; Condon, J. J.; Gao, F.; Henkel, C.; Litzinger, E.; Lo, K. Y.; Reid, M. J.

    2015-09-01

    We use single-dish radio spectra of known 22 GHz H2O megamasers, primarily gathered from the large data set observed by the Megamaser Cosmology Project, to identify Keplerian accretion disks and to investigate several aspects of the disk physics. We test a mechanism for maser excitation proposed by Maoz & McKee (1998), whereby population inversion arises in gas behind spiral shocks traveling through the disk. Though the flux of redshifted features is larger on average than that of blueshifted features, in support of the model, the high-velocity features show none of the predicted systematic velocity drifts. We find rapid intra-day variability in the maser spectrum of ESO 558-G009 that is likely the result of interstellar scintillation, for which we favor a nearby (D ≈ 70 pc) scattering screen. In a search for reverberation in six well-sampled sources, we find that any radially propagating signal must be contributing ≲10% of the total variability. We also set limits on the magnetic field strengths in seven sources, using strong flaring events to check for the presence of Zeeman splitting. These limits are typically 200-300 mG (1σ), but our most stringent limits reach down to 73 mG for the galaxy NGC 1194.

  16. Search for Beyond the Standard Model Physics at D0

    SciTech Connect

    Kraus, James

    2011-08-01

    The standard model (SM) of particle physics has been remarkably successful at predicting the outcomes of particle physics experiments, but there are reasons to expect new physics at the electroweak scale. Over the last several years, there have been a number of searches for beyond the standard model (BSM) physics at D0. Here, we limit our focus to three: searches for diphoton events with large missing transverse energy (E{sub T}), searches for leptonic jets and E{sub T}, and searches for single vector-like quarks. We have discussed three recent searches at D0. There are many more, including limits on heavy neutral gauge boson in the ee channel, a search for scalar top quarks, a search for quirks, and limits on a new resonance decaying to WW or WZ.

  17. Physical models of hydrofracturing across material interfaces

    SciTech Connect

    Blair, S.C.; Thorpe, R.K.; Heuze, F.E.

    1988-10-01

    We have performed a series of laboratory tests to study the propagation of a hydrofracture into and through an interface between two rock-like materials. The aim of this research is to provide improved diagnostics for stimulating lenticular gas sand reservoirs by interpreting features of the injection pressure-time record caused by interaction of a hydrofracture with a geologic discontinuity. Results will also be used to validate conceptual models of hydrofracture behavior in discontinuous media, such as are embodied in the LLNL FEFFLAP code, a two-dimensional fracture propagation computer program. We prepared test specimens by embedding sandstone tablets (lenses) in blocks of gypsum cement. These blocks were hydrofractured under true triaxial loading conditions, at a constant injection rate. The injection path was designed so that we obtained a single-wing fracture, propagating in a plane perpendicular to the interface. The vertical extent of the fractures was controlled by means of wire mesh screen embedded in the blocks, perpendicular to the injection tube. Growth of the fractures was tracked via extension failure of fine tungsten wires embedded in the gypsum. After testing, we dissected the blocks and recorded the extent of fracturing and fluid penetration. Cross-sections of the fractures indicate that they were of constant height and propagated through the sandstone tablet. All the fractures showed step-crack behavior upon entering or exiting the sandstone tablet. Pressure-time and fracture tracking data were consistent for all tests. Distinct step increases on the pressure- time record were also noted in all tests, and are related to the interaction of the hydrofracture with the sandstone lens. 16 refs., 19 figs., 4 tabs.

  18. Structure Modeling and Validation applied to Source Physics Experiments (SPEs)

    NASA Astrophysics Data System (ADS)

    Larmat, C. S.; Rowe, C. A.; Patton, H. J.

    2012-12-01

    The U. S. Department of Energy's Source Physics Experiments (SPEs) comprise a series of small chemical explosions used to develop a better understanding of seismic energy generation and wave propagation for low-yield explosions. In particular, we anticipate improved understanding of the processes through which shear waves are generated by the explosion source. Three tests, 100, 1000 and 1000 kg yields respectively, were detonated in the same emplacement hole and recorded on the same networks of ground motion sensors in the granites of Climax Stock at the Nevada National Security Site. We present results for the analysis and modeling of seismic waveforms recorded close-in on five linear geophone lines extending radially from ground zero, having offsets from 100 to 2000 m and station spacing of 100 m. These records exhibit azimuthal variations of P-wave arrival times, and phase velocity, spreading and attenuation properties of high-frequency Rg waves. We construct a 1D seismic body-wave model starting from a refraction analysis of P-waves and adjusting to address time-domain and frequency-domain dispersion measurements of Rg waves between 2 and 9 Hz. The shallowest part of the structure we address using the arrival times recorded by near-field accelerometers residing within 200 m of the shot hole. We additionally perform a 2D modeling study with the Spectral Element Method (SEM) to investigate which structural features are most responsible for the observed variations, in particular anomalously weak amplitude decay in some directions of this topographically complicated locality. We find that a near-surface, thin, weathered layer of varying thickness and low wave speeds plays a major role on the observed waveforms. We anticipate performing full 3D modeling of the seismic near-field through analysis and validation of waveforms on the 5 radial receiver arrays.

  19. A physical model of Titan's aerosols.

    PubMed

    Toon, O B; McKay, C P; Griffith, C A; Turco, R P

    1992-01-01

    Microphysical simulations of Titan's stratospheric haze show that aerosol microphysics is linked to organized dynamical processes. The detached haze layer may be a manifestation of 1 cm sec-1 vertical velocities at altitudes above 300 km. The hemispherical asymmetry in the visible albedo may be caused by 0.05 cm sec-1 vertical velocities at altitudes of 150 to 200 km, we predict contrast reversal beyond 0.6 micrometer. Tomasko and Smith's (1982, Icarus 51, 65-95) model, in which a layer of large particles above 220 km altitude is responsible for the high forward scattering observed by Rages and Pollack (1983, Icarus 55, 50-62), is a natural outcome of the detached haze layer being produced by rising motions if aerosol mass production occurs primarily below the detached haze layer. The aerosol's electrical charge is critical for the particle size and optical depth of the haze. The geometric albedo, particularly in the ultraviolet and near infrared, requires that the particle size be near 0.15 micrometer down to altitudes below 100 km, which is consistent with polarization observations (Tomasko and Smith 1982, West and Smith 1991, Icarus 90, 330-333). Above about 400 km and below about 150 km Yung et al.'s (1984, Astrophys. J. Suppl. Ser. 55, 465-506) diffusion coefficients are too small. Dynamical processes control the haze particles below about 150 km. The relatively large eddy diffusion coefficients in the lower stratosphere result in a vertically extensive region with nonuniform mixing ratios of condensable gases, so that most hydrocarbons may condense very near the tropopause rather than tens of kilometers above it. The optical depths of hydrocarbon clouds are probably less than one, requiring that abundant gases such as ethane condense on a subset of the haze particles to create relatively large, rapidly removed particles. The wavelength dependence of the optical radius is calculated for use in analyzing observations of the geometric albedo. The lower

  20. Female role models in physics education in Ireland

    NASA Astrophysics Data System (ADS)

    Chormaic, Síle Nic; Fee, Sandra; Tobin, Laura; Hennessy, Tara

    2013-03-01

    In this paper we consider the statistics on undergraduate student representation in Irish universities and look at student numbers in secondary (high) schools in one region in Ireland. There seems to be no significant change in female participation in physics from 2002 to 2011. Additionally, we have studied the influence of an educator's gender on the prevalence of girls studying physics in secondary schools in Co. Louth, Ireland, and at the postgraduate level in Irish universities. It would appear that strong female role models have a positive influence and lead to an increase in girls' participation in physics.

  1. Physical and numerical modeling of Joule-heated melters

    NASA Astrophysics Data System (ADS)

    Eyler, L. L.; Skarda, R. J.; Crowder, R. S., III; Trent, D. S.; Reid, C. R.; Lessor, D. L.

    1985-10-01

    The Joule-heated ceramic-lined melter is an integral part of the high level waste immobilization process under development by the US Department of Energy. Scaleup and design of this waste glass melting furnace requires an understanding of the relationships between melting cavity design parameters and the furnace performance characteristics such as mixing, heat transfer, and electrical requirements. Developing empirical models of these relationships through actual melter testing with numerous designs would be a very costly and time consuming task. Additionally, the Pacific Northwest Laboratory (PNL) has been developing numerical models that simulate a Joule-heated melter for analyzing melter performance. This report documents the method used and results of this modeling effort. Numerical modeling results are compared with the more conventional, physical modeling results to validate the approach. Also included are the results of numerically simulating an operating research melter at PNL. Physical Joule-heated melters modeling results used for qualiying the simulation capabilities of the melter code included: (1) a melter with a single pair of electrodes and (2) a melter with a dual pair (two pairs) of electrodes. The physical model of the melter having two electrode pairs utilized a configuration with primary and secondary electrodes. The principal melter parameters (the ratio of power applied to each electrode pair, modeling fluid depth, electrode spacing) were varied in nine tests of the physical model during FY85. Code predictions were made for five of these tests. Voltage drops, temperature field data, and electric field data varied in their agreement with the physical modeling results, but in general were judged acceptable.

  2. Physical and numerical modeling of Joule-heated melters

    SciTech Connect

    Eyler, L.L.; Skarda, R.J.; Crowder, R.S. III; Trent, D.S.; Reid, C.R.; Lessor, D.L.

    1985-10-01

    The Joule-heated ceramic-lined melter is an integral part of the high level waste immobilization process under development by the US Department of Energy. Scaleup and design of this waste glass melting furnace requires an understanding of the relationships between melting cavity design parameters and the furnace performance characteristics such as mixing, heat transfer, and electrical requirements. Developing empirical models of these relationships through actual melter testing with numerous designs would be a very costly and time consuming task. Additionally, the Pacific Northwest Laboratory (PNL) has been developing numerical models that simulate a Joule-heated melter for analyzing melter performance. This report documents the method used and results of this modeling effort. Numerical modeling results are compared with the more conventional, physical modeling results to validate the approach. Also included are the results of numerically simulating an operating research melter at PNL. Physical Joule-heated melters modeling results used for qualiying the simulation capabilities of the melter code included: (1) a melter with a single pair of electrodes and (2) a melter with a dual pair (two pairs) of electrodes. The physical model of the melter having two electrode pairs utilized a configuration with primary and secondary electrodes. The principal melter parameters (the ratio of power applied to each electrode pair, modeling fluid depth, electrode spacing) were varied in nine tests of the physical model during FY85. Code predictions were made for five of these tests. Voltage drops, temperature field data, and electric field data varied in their agreement with the physical modeling results, but in general were judged acceptable. 14 refs., 79 figs., 17 tabs.

  3. The Immediate Exchange model: an analytical investigation

    NASA Astrophysics Data System (ADS)

    Katriel, Guy

    2015-01-01

    We study the Immediate Exchange model, recently introduced by Heinsalu and Patriarca [Eur. Phys. J. B 87, 170 (2014)], who showed by simulations that the wealth distribution in this model converges to a Gamma distribution with shape parameter 2. Here we justify this conclusion analytically, in the infinite-population limit. An infinite-population version of the model is derived, describing the evolution of the wealth distribution in terms of iterations of a nonlinear operator on the space of probability densities. It is proved that the Gamma distributions with shape parameter 2 are fixed points of this operator, and that, starting with an arbitrary wealth distribution, the process converges to one of these fixed points. We also discuss the mixed model introduced in the same paper, in which exchanges are either bidirectional or unidirectional with fixed probability. We prove that, although, as found by Heinsalu and Patriarca, the equilibrium distribution can be closely fit by Gamma distributions, the equilibrium distribution for this model is not a Gamma distribution.

  4. Numerical investigation of the seismo-acoustic responses of the Source Physics Experiment underground explosions

    NASA Astrophysics Data System (ADS)

    Antoun, T.; Ezzedine, S. M.; Vorobiev, O.; Glenn, L. A.

    2015-12-01

    We have performed three-dimensional high resolution simulations of underground explosions conducted recently in jointed rock outcrop as part of the Source Physics Experiment (SPE) being conducted at the Nevada National Security Site (NNSS). The main goal of the current study is to investigate the effects of the structural and geomechanical properties on the spall phenomena due to underground explosions and its subsequent effect on the seismo-acoustic signature at far distances. Two parametric studies have been undertaken to assess the impact of different 1) conceptual geological models including a single layer and two layers model, with and without joints and with and without varying geomechanical properties, and 2) depth of bursts of the explosions and explosion yields. Through these investigations we have explored not only the near-field response of the explosions but also the far-field responses of the seismic and the acoustic signatures. The near-field simulations were conducted using the Eulerian and Lagrangian codes, GEODYN and GEODYN -L, respectively, while the far-field seismic simulations were conducted using the elastic wave propagation code, WPP, and the acoustic response using the Kirchhoff-Helmholtz-Rayleigh time-dependent approximation code, KHR. Though a series of simulations, we have recorded the velocity field histories a) at the ground surface on an acoustic-source-patch for the acoustic simulations, and 2) on a seismic-source-box for the seismic simulations. We first analyzed the SPE3 and SPE4-prime experimental data and simulated results, and then simulated SPE5, SPE6/7 to anticipate their seismo-acoustic responses given conditions of uncertainties. SPE experiments were conducted in a granitic formation; we have extended the parametric study to include other geological settings such dolomite and alluvial formations. These parametric studies enabled us 1) investigating the geotechnical and geophysical key parameters that impact the seismo

  5. An investigation into field effects of consciousness from the perspectives of Maharishi's Vedic Science and physics

    NASA Astrophysics Data System (ADS)

    Kleinschnitz, Kurt Warren

    1997-05-01

    A long-range field effect of consciousness has been reported repeatedly in the scientific literature over the past twenty years. This phenomenon is called the Maharishi Effect, after Maharishi Mahesh Yogi, the first to predict it. The Maharishi Effect is the phenomenon of improved societal trends resulting from the practice of the Transcendental Meditationoler program or group practice of the TM-Sidhioler program by a small fraction of a population. The Maharishi Effect is fundamentally a phenomenon of radiation of evolutionary influence arising from the enlivenment of pure consciousness, the unified field of natural law, in the perspective of Maharishi's Vedic Science. This perspective is corroborated by forty-three published or presented papers reporting on results of Maharishi Effect interventions world-wide at city, national, international, and global scales. Present day standard- model physics and physiology do not account for the outcomes of the research on the Maharishi Effect. Because the observed societal impact of the Maharishi Effect influence must be based in an impact on the individual, and investigators report detection of the effect in individual physiological measurements, a simple robust indicator for the effect might aid physiologists and physicists in the effort to extend their sciences to include such field effects of consciousness. Thus, this dissertation reports on two experiments investigating simple, robust, objective indicators for the effect. The dissertation concludes on a practical note with a description of the promise, available through concerted utilization of the knowledge and technologies of consciousness in Maharishi's Vedic Science, for enhanced national and global security in the face of unprecedented nuclear, biological, and genetic threats for which the modern sciences offer few sensible solutions. ftnolerTranscendental Meditation and TM-Sidhi are service marks registered in the United States Patent and Trademark Office

  6. Retrospective examination of injuries and physical fitness during Federal Bureau of Investigation new agent training

    PubMed Central

    2011-01-01

    Background A retrospective examination was conducted of injuries, physical fitness, and their association among Federal Bureau of Investigation (FBI) new agent trainees. Methods Injuries and activities associated with injuries were obtained from a review of medical records in the medical clinic that served the new agents. A physical fitness test (PFT) was administered at Weeks 1, 7 and 14 of the 17-week new agent training course. The PFT consisted of push-ups, sit-ups, pull-ups, a 300-meter sprint, and a 1.5-mile run. Injury data were available from 2000 to 2008 and fitness data were available from 2004 to early 2009. Results During the survey period, 37% of men and 44% of women experienced one or more injuries during the new agent training course (risk ratio (women/men) = 1.18, 95% confidence interval = 1.07-1.31). The most common injury diagnoses were musculoskeletal pain (not otherwise specified) (27%), strains (11%), sprains (10%), contusions (9%), and abrasions/lacerations (9%). Activities associated with injury included defensive tactics training (48%), physical fitness training (26%), physical fitness testing (6%), and firearms training (6%). Over a 6-year period, there was little difference in performance of push-ups, sit-ups, pull-ups, or the 300-meter sprint; 1.5-mile run performance was higher in recent years. Among both men and women, higher injury incidence was associated with lower performance on any of the physical fitness measures. Conclusion This investigation documented injury diagnoses, activities associated with injury, and changes in physical fitness, and demonstrated that higher levels of physical fitness were associated with lower injury risk. PMID:21981817

  7. Retrospective examination of injuries and physical fitness during Federal Bureau of Investigation new agent training.

    PubMed

    Knapik, Joseph J; Spiess, Anita; Swedler, David; Grier, Tyson; Hauret, Keith; Yoder, James; Jones, Bruce H

    2011-10-09

    A retrospective examination was conducted of injuries, physical fitness, and their association among Federal Bureau of Investigation (FBI) new agent trainees. Injuries and activities associated with injuries were obtained from a review of medical records in the medical clinic that served the new agents. A physical fitness test (PFT) was administered at Weeks 1, 7 and 14 of the 17-week new agent training course. The PFT consisted of push-ups, sit-ups, pull-ups, a 300-meter sprint, and a 1.5-mile run. Injury data were available from 2000 to 2008 and fitness data were available from 2004 to early 2009. During the survey period, 37% of men and 44% of women experienced one or more injuries during the new agent training course (risk ratio (women/men) = 1.18, 95% confidence interval = 1.07-1.31). The most common injury diagnoses were musculoskeletal pain (not otherwise specified) (27%), strains (11%), sprains (10%), contusions (9%), and abrasions/lacerations (9%). Activities associated with injury included defensive tactics training (48%), physical fitness training (26%), physical fitness testing (6%), and firearms training (6%). Over a 6-year period, there was little difference in performance of push-ups, sit-ups, pull-ups, or the 300-meter sprint; 1.5-mile run performance was higher in recent years. Among both men and women, higher injury incidence was associated with lower performance on any of the physical fitness measures. This investigation documented injury diagnoses, activities associated with injury, and changes in physical fitness, and demonstrated that higher levels of physical fitness were associated with lower injury risk.

  8. A physical data model for fields and agents

    NASA Astrophysics Data System (ADS)

    de Jong, Kor; de Bakker, Merijn; Karssenberg, Derek

    2016-04-01

    Two approaches exist in simulation modeling: agent-based and field-based modeling. In agent-based (or individual-based) simulation modeling, the entities representing the system's state are represented by objects, which are bounded in space and time. Individual objects, like an animal, a house, or a more abstract entity like a country's economy, have properties representing their state. In an agent-based model this state is manipulated. In field-based modeling, the entities representing the system's state are represented by fields. Fields capture the state of a continuous property within a spatial extent, examples of which are elevation, atmospheric pressure, and water flow velocity. With respect to the technology used to create these models, the domains of agent-based and field-based modeling have often been separate worlds. In environmental modeling, widely used logical data models include feature data models for point, line and polygon objects, and the raster data model for fields. Simulation models are often either agent-based or field-based, even though the modeled system might contain both entities that are better represented by individuals and entities that are better represented by fields. We think that the reason for this dichotomy in kinds of models might be that the traditional object and field data models underlying those models are relatively low level. We have developed a higher level conceptual data model for representing both non-spatial and spatial objects, and spatial fields (De Bakker et al. 2016). Based on this conceptual data model we designed a logical and physical data model for representing many kinds of data, including the kinds used in earth system modeling (e.g. hydrological and ecological models). The goal of this work is to be able to create high level code and tools for the creation of models in which entities are representable by both objects and fields. Our conceptual data model is capable of representing the traditional feature data

  9. A Goddard Multi-Scale Modeling System with Unified Physics

    NASA Technical Reports Server (NTRS)

    Tao, W.K.; Anderson, D.; Atlas, R.; Chern, J.; Houser, P.; Hou, A.; Lang, S.; Lau, W.; Peters-Lidard, C.; Kakar, R.; Kumar, S.; Lapenta, W.; Li, X.; Matsui, T.; Rienecker, M.; Shen, B.W.; Shi, J.J.; Simpson, J.; Zeng, X.

    2008-01-01

    Numerical cloud resolving models (CRMs), which are based the non-hydrostatic equations of motion, have been extensively applied to cloud-scale and mesoscale processes during the past four decades. Recent GEWEX Cloud System Study (GCSS) model comparison projects have indicated that CRMs agree with observations in simulating various types of clouds and cloud systems from different geographic locations. Cloud resolving models now provide statistical information useful for developing more realistic physically based parameterizations for climate models and numerical weather prediction models. It is also expected that Numerical Weather Prediction (NWP) and regional scale model can be run in grid size similar to cloud resolving model through nesting technique. Current and future NASA satellite programs can provide cloud, precipitation, aerosol and other data at very fine spatial and temporal scales. It requires a coupled global circulation model (GCM) and cloud-scale model (termed a szrper-parameterization or multi-scale modeling -framework, MMF) to use these satellite data to improve the understanding of the physical processes that are responsible for the variation in global and regional climate and hydrological systems. The use of a GCM will enable global coverage, and the use of a CRM will allow for better and more sophisticated physical parameterization. NASA satellite and field campaign can provide initial conditions as well as validation through utilizing the Earth Satellite simulators. At Goddard, we have developed a multi-scale modeling system with unified physics. The modeling system consists a coupled GCM-CRM (or MMF); a state-of-the-art weather research forecast model (WRF) and a cloud-resolving model (Goddard Cumulus Ensemble model). In these models, the same microphysical schemes (2ICE, several 3ICE), radiation (including explicitly calculated cloud optical properties), and surface models are applied. In addition, a comprehensive unified Earth Satellite

  10. Physically representative atomistic modeling of atomic-scale friction

    NASA Astrophysics Data System (ADS)

    Dong, Yalin

    Nanotribology is a research field to study friction, adhesion, wear and lubrication occurred between two sliding interfaces at nano scale. This study is motivated by the demanding need of miniaturization mechanical components in Micro Electro Mechanical Systems (MEMS), improvement of durability in magnetic storage system, and other industrial applications. Overcoming tribological failure and finding ways to control friction at small scale have become keys to commercialize MEMS with sliding components as well as to stimulate the technological innovation associated with the development of MEMS. In addition to the industrial applications, such research is also scientifically fascinating because it opens a door to understand macroscopic friction from the most bottom atomic level, and therefore serves as a bridge between science and engineering. This thesis focuses on solid/solid atomic friction and its associated energy dissipation through theoretical analysis, atomistic simulation, transition state theory, and close collaboration with experimentalists. Reduced-order models have many advantages for its simplification and capacity to simulating long-time event. We will apply Prandtl-Tomlinson models and their extensions to interpret dry atomic-scale friction. We begin with the fundamental equations and build on them step-by-step from the simple quasistatic one-spring, one-mass model for predicting transitions between friction regimes to the two-dimensional and multi-atom models for describing the effect of contact area. Theoretical analysis, numerical implementation, and predicted physical phenomena are all discussed. In the process, we demonstrate the significant potential for this approach to yield new fundamental understanding of atomic-scale friction. Atomistic modeling can never be overemphasized in the investigation of atomic friction, in which each single atom could play a significant role, but is hard to be captured experimentally. In atomic friction, the

  11. Improving documentation of physical health investigations in an adolescent mental health inpatient unit.

    PubMed

    Horton, David

    2015-01-01

    Physical health investigations, such as blood tests, ECGs, and appropriate radiological tests, are essential in the assessment and management of many patients in inpatient mental health settings. This project took place in a 12-bed adolescent mental health unit in Swindon, UK, where on average at least two-thirds of patients have a diagnosed eating disorder. Multidisciplinary ward rounds provide an appropriate setting for discussion and documentation of physical investigations. Over a two-week period, 22 electronic ward round entries were audited for any documentation of five common investigations - blood tests, ECG, MRI head, DEXA, and ovarian ultrasound. Blood tests were documented in 2/22 (9.1%), ECG, MRI head, DEXA, and ovarian ultrasound were documented in 0/22 (0%). Modifications were made to an electronic ward round template, to include headings for each of these investigations, with free-text boxes as well as drop-down boxes for the radiological tests. Following this, re-audit of 22 ward round entries over a two-week period showed documentation had hugely improved - blood tests were documented in 21/22 (95.5%), with ECG, MRI head, DEXA, and pelvis US all documented in 22/22 (100%). A further audit a month later showed these results were largely sustained. In conclusion, use of a simple, structured ward round template can hugely improve documentation of important physical investigations within mental health settings.

  12. Improving documentation of physical health investigations in an adolescent mental health inpatient unit

    PubMed Central

    Horton, David

    2015-01-01

    Physical health investigations, such as blood tests, ECGs, and appropriate radiological tests, are essential in the assessment and management of many patients in inpatient mental health settings. This project took place in a 12-bed adolescent mental health unit in Swindon, UK, where on average at least two-thirds of patients have a diagnosed eating disorder. Multidisciplinary ward rounds provide an appropriate setting for discussion and documentation of physical investigations. Over a two-week period, 22 electronic ward round entries were audited for any documentation of five common investigations - blood tests, ECG, MRI head, DEXA, and ovarian ultrasound. Blood tests were documented in 2/22 (9.1%), ECG, MRI head, DEXA, and ovarian ultrasound were documented in 0/22 (0%). Modifications were made to an electronic ward round template, to include headings for each of these investigations, with free-text boxes as well as drop-down boxes for the radiological tests. Following this, re-audit of 22 ward round entries over a two-week period showed documentation had hugely improved - blood tests were documented in 21/22 (95.5%), with ECG, MRI head, DEXA, and pelvis US all documented in 22/22 (100%). A further audit a month later showed these results were largely sustained. In conclusion, use of a simple, structured ward round template can hugely improve documentation of important physical investigations within mental health settings. PMID:26734411

  13. Investigation of the physical properties of tricalcium silicate cement-based root-end filling materials.

    PubMed

    Grech, L; Mallia, B; Camilleri, J

    2013-02-01

    Tricalcium silicate-based cements have been displayed as suitable root-end filling materials. The physical properties of prototype radiopacified tricalcium silicate cement, Bioaggregate and Biodentine were investigated. Intermediate restorative material was used as a control. The physical properties of a prototype zirconium oxide replaced tricalcium silicate cement and two proprietary cements composed of tricalcium silicate namely Bioaggregate and Biodentine were investigated. Intermediate restorative material (IRM) was used as a control. Radiopacity assessment was undertaken and expressed in thickness of aluminum. In addition the anti-washout resistance was investigated using a novel basket-drop method and the fluid uptake, sorption and solubility were investigated using a gravimetric method. The setting time was assessed using an indentation technique and compressive strength and micro-hardness of the test materials were investigated. All the testing was performed with the test materials immersed in Hank's balanced salt solution. All the materials tested had a radiopacity value higher than 3mm thickness of aluminum. IRM exhibited the highest radiopacity. Biodentine demonstrated a high washout, low fluid uptake and sorption values, low setting time and superior mechanical properties. The fluid uptake and setting time was the highest for Bioaggregate. The addition of admixtures to tricalcium silicate-based cements affects the physical properties of the materials. Copyright © 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  14. Investigating Nitrogen Pollution: Activities and Models.

    ERIC Educational Resources Information Center

    Green Teacher, 2000

    2000-01-01

    Introduces activities on nitrogen, nitrogen pollution from school commuters, nitrogen response in native and introduced species, and nutrient loading models. These activities help students determine the nitrogen contribution from their parents' cars, test native plant responses to nitrogen, and experiment with the results of removing water from…

  15. Investigating Nitrogen Pollution: Activities and Models.

    ERIC Educational Resources Information Center

    Green Teacher, 2000

    2000-01-01

    Introduces activities on nitrogen, nitrogen pollution from school commuters, nitrogen response in native and introduced species, and nutrient loading models. These activities help students determine the nitrogen contribution from their parents' cars, test native plant responses to nitrogen, and experiment with the results of removing water from…

  16. Investigating the Effect of Damage Progression Model Choice on Prognostics Performance

    NASA Technical Reports Server (NTRS)

    Daigle, Matthew; Roychoudhury, Indranil; Narasimhan, Sriram; Saha, Sankalita; Saha, Bhaskar; Goebel, Kai

    2011-01-01

    The success of model-based approaches to systems health management depends largely on the quality of the underlying models. In model-based prognostics, it is especially the quality of the damage progression models, i.e., the models describing how damage evolves as the system operates, that determines the accuracy and precision of remaining useful life predictions. Several common forms of these models are generally assumed in the literature, but are often not supported by physical evidence or physics-based analysis. In this paper, using a centrifugal pump as a case study, we develop different damage progression models. In simulation, we investigate how model changes influence prognostics performance. Results demonstrate that, in some cases, simple damage progression models are sufficient. But, in general, the results show a clear need for damage progression models that are accurate over long time horizons under varied loading conditions.

  17. Investigating diet and physical activity in Malaysia: education and family history of diabetes relate to lower levels of physical activity

    PubMed Central

    Tam, Cai Lian; Bonn, Gregory; Yeoh, Si Han; Wong, Chee Piau

    2014-01-01

    The National Health and Morbidity Survey (NHMS, 2011), estimates that the number of Malaysian adults suffering from type 2 diabetes has increased from 8.3 to 31.2% since 1996. This study is a preliminary investigation of possible factors contributing to this epidemic. Knowledge of diabetes, health locus of control, diet and exercise habits, as well as family history, education level and other demographic factors to better understand the correlates of risky and healthy behaviors. This was done as part of a larger initiative to improve prevention efforts. Questionnaires were completed by 770 individuals from three Malaysian states: Selangor, Penang, and Terengganu. Findings showed that people with better health knowledge and those who have a family history of type 2 diabetes were more likely to have healthy diets. Also, health knowledge related to lower alcohol consumption. Participants with diabetic family members, however, also reported higher levels of stress. Counterintuitively, higher educational levels, higher internal locus of control, better health knowledge, as well as a family history of diabetes all correlated with lower levels of physical activity. Thus, it is suggested that, while increasing health knowledge will be important in addressing the type 2 diabetes epidemic in Malaysia, especially in relation to diet, other cultural factors, specifically norms related to exercise and physical activity, also need to be addressed if the spread of type 2 diabetes is to be addressed over the long term. PMID:25520676

  18. Investigating diet and physical activity in Malaysia: education and family history of diabetes relate to lower levels of physical activity.

    PubMed

    Tam, Cai Lian; Bonn, Gregory; Yeoh, Si Han; Wong, Chee Piau

    2014-01-01

    The National Health and Morbidity Survey (NHMS, 2011), estimates that the number of Malaysian adults suffering from type 2 diabetes has increased from 8.3 to 31.2% since 1996. This study is a preliminary investigation of possible factors contributing to this epidemic. Knowledge of diabetes, health locus of control, diet and exercise habits, as well as family history, education level and other demographic factors to better understand the correlates of risky and healthy behaviors. This was done as part of a larger initiative to improve prevention efforts. Questionnaires were completed by 770 individuals from three Malaysian states: Selangor, Penang, and Terengganu. Findings showed that people with better health knowledge and those who have a family history of type 2 diabetes were more likely to have healthy diets. Also, health knowledge related to lower alcohol consumption. Participants with diabetic family members, however, also reported higher levels of stress. Counterintuitively, higher educational levels, higher internal locus of control, better health knowledge, as well as a family history of diabetes all correlated with lower levels of physical activity. Thus, it is suggested that, while increasing health knowledge will be important in addressing the type 2 diabetes epidemic in Malaysia, especially in relation to diet, other cultural factors, specifically norms related to exercise and physical activity, also need to be addressed if the spread of type 2 diabetes is to be addressed over the long term.

  19. Body shape model, physical activity and eating behaviour.

    PubMed

    Jáuregui Lobera, I; Tomillo Cid, S; Santiago Fernández, M J; Bolaños Ríos, P

    2011-01-01

    Research on the influence of body shape model on adolescent males is scarce. The current study aimed to assess this influence among adult males involved in intense physical activity and to determine its relationship to eating behaviour. Possible variations between 1998 and 2008 were also analysed. A total of 950 males (672 in 1998 and 278 in 2008), all aspiring professional soldiers, were studied using the Questionnaire of Influences on Body Shape Model (CIMEC-V) and the Eating Attitudes Test-40 (EAT-40), as well as by assessing their physical/sporting activity and body mass index (BMI). Scores on the CIMEC-V were significantly correlated with the EAT-40 and BMI. As regards physical activity the only positive correlation referred to gym-based exercise. A cluster analysis revealed two subgroups with respect to physical activity, BMI, and scores on the CIMEC-V and EAT-40. One of them scored higher on these three variables and they also had a BMI > 25. The comparative study of data from 1998 and 2008 showed significant changes in some variables. Generally, the results differ considerably from those reported for younger samples (which would suggest a lower risk of disordered eating behaviour). However, there is a higher risk group in which the influence of body shape models, physical activity and eating behaviour are related to greater body volume. The influence of the body shape model on males has increased, especially as regards the influence of friends and in terms of behaviours aimed at weight loss.

  20. Memphis Harbor, Mississippi River: Model Investigation

    DTIC Science & Technology

    1950-12-01

    MEMORANDUM NO. 2 -320 CONDUCTED F OR THE PRESIDENT, MISSISSIPPI RIVER COMMISSION ARMY·MRC.VICKSBURG. MISS. CORPS OF ENGINEERS, U. S. ARMY BY...failing to comply with a collection of information if it does not display a currently valid OMB control number 1. REPORT DATE DEC 1950 2 . REPORT TYPE...second wrapper indorsement to Waterways Experiment Station letter dated 2 October 1946, subject: "Proposed Model Study, Presidents Island, Mississippi

  1. Investigating the associations between Mediterranean diet, physical activity and living environment with childhood asthma using path analysis.

    PubMed

    Alphantonogeorgos, George; Panagiotakos, Demosthenes B; Grigoropoulou, Dimitra; Yfanti, Konstantina; Papoutsakis, Constantina; Papadimitriou, Anastasios; Anthracopoulos, Michael B; Bakoula, Chryssa; Priftis, Kostas N

    2014-01-01

    To investigate the role of the Mediterranean diet and physical activity with relation to living environment and childhood asthma. 1125 children (529 boys), 10 to 12 years old were recruited either in an urban environment (Athens, n = 700) or rural environment (n = 425) in Greece. A path analytic model was developed to assess the causal relation between urban environment and asthma prevalence (standardized ISAAC questionnaire), through the mediation of the Mediterranean diet (evaluated by the KIDMED food frequency questionnaire) and physical activity (evaluated by the PALQ physical activity questionnaire). The proposed model had a very good fit (χ2/df ratio =1.05, RMSEA=0.007, 90% confidence interval: 0.01 to 0.046, p=0.97, CFI = 0.98). A significant total positive effect was found between urban environment and asthma symptoms (standardized beta= 0.09, p<0.001). Adherence to the Mediterranean diet was related negatively with asthma symptoms (standardized beta = -0.224, p<0.001). An inverse mediating effect of the Mediterranean diet was observed for the urban environment - asthma relation (standardized beta=-0.029, p<0.001) while physical activity had no significant contribution (p=0.62), adjusted for several confounders. The Mediterranean diet may protect against the harmful effect of urban environment on childhood asthma.

  2. A physics based investigation of Gurney flaps for enhancement of rotorcraft flight characteristics

    NASA Astrophysics Data System (ADS)

    Min, Byung-Young

    Helicopters are versatile vehicles that can vertically take off and land, hover, and perform maneuver at very low forward speeds. These characteristics make them unique for a number of civilian and military applications. However, the radial and azimuthal variation of dynamic pressure causes rotors to experience adverse phenomena such as transonic shocks and 3-D dynamic stall. Adverse interactions such as blade vortex interaction and rotor-airframe interaction may also occur. These phenomena contribute to noise and vibrations. Finally, in the event of an engine failure, rotorcraft tends to descend at high vertical velocities causing structural damage and loss of lives. A variety of techniques have been proposed for reducing the noise and vibrations. These techniques include on-board control (OBC) devices, individual blade control (IBC), and higher harmonic control (HHC). Addition of these devices adds to the weight, cost, and complexity of the rotor system, and reduces the reliability of operations. Simpler OBC concepts will greatly alleviate these drawbacks and enhance the operating envelope of vehicles. In this study, the use of Gurney flaps is explored as an OBC concept using a physics based approach. A three dimensional Navier-Stokes solver developed by the present investigator is coupled to an existing free wake model of the wake structure. The method is further enhanced for modeling of Blade-Vortex-Interactions (BVI). Loose coupling with an existing comprehensive structural dynamics analysis solver (DYMORE) is implemented for the purpose of rotor trim and modeling of aeroelastic effects. Results are presented for Gurney flaps as an OBC concept for improvements in autorotation, rotor vibration reduction, and BVI characteristics. As a representative rotor, the HART-II model rotor is used. It is found that the Gurney flap increases propulsive force in the driving region while the drag force is increased in the driven region. It is concluded that the deployable

  3. Climate model forecast biases assessed with a perturbed physics ensemble

    NASA Astrophysics Data System (ADS)

    Mulholland, David P.; Haines, Keith; Sparrow, Sarah N.; Wallom, David

    2017-09-01

    Perturbed physics ensembles have often been used to analyse long-timescale climate model behaviour, but have been used less often to study model processes on shorter timescales. We combine a transient perturbed physics ensemble with a set of initialised forecasts to deduce regional process errors present in the standard HadCM3 model, which cause the model to drift in the early stages of the forecast. First, it is shown that the transient drifts in the perturbed physics ensembles can be used to recover quantitatively the parameters that were perturbed. The parameters which exert most influence on the drifts vary regionally, but upper ocean mixing and atmospheric convective processes are particularly important on the 1-month timescale. Drifts in the initialised forecasts are then used to recover the `equivalent parameter perturbations', which allow identification of the physical processes that may be at fault in the HadCM3 representation of the real world. Most parameters show positive and negative adjustments in different regions, indicating that standard HadCM3 values represent a global compromise. The method is verified by correcting an unusually widespread positive bias in the strength of wind-driven ocean mixing, with forecast drifts reduced in a large number of areas as a result. This method could therefore be used to improve the skill of initialised climate model forecasts by reducing model biases through regional adjustments to physical processes, either by tuning or targeted parametrisation refinement. Further, such regionally tuned models might also significantly outperform standard climate models, with global parameter configurations, in longer-term climate studies.

  4. Climate model forecast biases assessed with a perturbed physics ensemble

    NASA Astrophysics Data System (ADS)

    Mulholland, David P.; Haines, Keith; Sparrow, Sarah N.; Wallom, David

    2016-10-01

    Perturbed physics ensembles have often been used to analyse long-timescale climate model behaviour, but have been used less often to study model processes on shorter timescales. We combine a transient perturbed physics ensemble with a set of initialised forecasts to deduce regional process errors present in the standard HadCM3 model, which cause the model to drift in the early stages of the forecast. First, it is shown that the transient drifts in the perturbed physics ensembles can be used to recover quantitatively the parameters that were perturbed. The parameters which exert most influence on the drifts vary regionally, but upper ocean mixing and atmospheric convective processes are particularly important on the 1-month timescale. Drifts in the initialised forecasts are then used to recover the `equivalent parameter perturbations', which allow identification of the physical processes that may be at fault in the HadCM3 representation of the real world. Most parameters show positive and negative adjustments in different regions, indicating that standard HadCM3 values represent a global compromise. The method is verified by correcting an unusually widespread positive bias in the strength of wind-driven ocean mixing, with forecast drifts reduced in a large number of areas as a result. This method could therefore be used to improve the skill of initialised climate model forecasts by reducing model biases through regional adjustments to physical processes, either by tuning or targeted parametrisation refinement. Further, such regionally tuned models might also significantly outperform standard climate models, with global parameter configurations, in longer-term climate studies.

  5. Combined physical and chemical nonequilibrium transport model for solution conduits.

    PubMed

    Field, Malcolm S; Leij, Feike J

    2014-02-01

    Solute transport in karst aquifers is primarily constrained to relatively complex and inaccessible solution conduits where transport is often rapid, turbulent, and at times constrictive. Breakthrough curves generated from tracer tests in solution conduits are typically positively-skewed with long tails evident. Physical nonequilibrium models to fit breakthrough curves for tracer tests in solution conduits are now routinely employed. Chemical nonequilibrium processes are likely important interactions, however. In addition to partitioning between different flow domains, there may also be equilibrium and nonequilibrium partitioning between the aqueous and solid phases. A combined physical and chemical nonequilibrium (PCNE) model was developed for an instantaneous release similar to that developed by Leij and Bradford (2009) for a pulse release. The PCNE model allows for partitioning open space in solution conduits into mobile and immobile flow regions with first-order mass transfer between the two regions to represent physical nonequilibrium in the conduit. Partitioning between the aqueous and solid phases proceeds either as an equilibrium process or as a first-order process and represents chemical nonequilibrium for both the mobile and immobile regions. Application of the model to three example breakthrough curves demonstrates the applicability of the combined physical and chemical nonequilibrium model to tracer tests conducted in karst aquifers, with exceptionally good model fits to the data. The three models, each from a different state in the United States, exhibit very different velocities, dispersions, and other transport properties with most of the transport occurring via the fraction of mobile water. Fitting the model suggests the potentially important interaction of physical and chemical nonequilibrium processes.

  6. A mathematical look at a physical power prediction model

    SciTech Connect

    Landberg, L.

    1997-12-31

    This paper takes a mathematical look at a physical model used to predict the power produced from wind farms. The reason is to see whether simple mathematical expressions can replace the original equations, and to give guidelines as to where the simplifications can be made and where they can not. This paper shows that there is a linear dependence between the geostrophic wind and the wind at the surface, but also that great care must be taken in the selection of the models since physical dependencies play a very important role, e.g. through the dependence of the turning of the wind on the wind speed.

  7. Physics-based model for electro-chemical process

    SciTech Connect

    Zhang, Jinsuo

    2013-07-01

    Considering the kinetics of electrochemical reactions and mass transfer at the surface and near-surface of the electrode, a physics-based separation model for separating actinides from fission products in an electro-refiner is developed. The model, taking into account the physical, chemical and electrochemical processes at the electrode surface, can be applied to study electrorefining kinetics. One of the methods used for validation has been to apply the developed model to the computation of the cyclic voltammetry process of PuCl{sub 3} and UCl{sub 3} at a solid electrode in molten KCl-LiCl. The computed results appear to be similar to experimental measures. The separation model can be applied to predict materials flows under normal and abnormal operation conditions. Parametric studies can be conducted based on the model to identify the most important factors that affect the electrorefining processes.

  8. Investigating habits: strategies, technologies and models

    PubMed Central

    Smith, Kyle S.; Graybiel, Ann M.

    2014-01-01

    Understanding habits at a biological level requires a combination of behavioral observations and measures of ongoing neural activity. Theoretical frameworks as well as definitions of habitual behaviors emerging from classic behavioral research have been enriched by new approaches taking account of the identification of brain regions and circuits related to habitual behavior. Together, this combination of experimental and theoretical work has provided key insights into how brain circuits underlying action-learning and action-selection are organized, and how a balance between behavioral flexibility and fixity is achieved. New methods to monitor and manipulate neural activity in real time are allowing us to have a first look “under the hood” of a habit as it is formed and expressed. Here we discuss ideas emerging from such approaches. We pay special attention to the unexpected findings that have arisen from our own experiments suggesting that habitual behaviors likely require the simultaneous activity of multiple distinct components, or operators, seen as responsible for the contrasting dynamics of neural activity in both cortico-limbic and sensorimotor circuits recorded concurrently during different stages of habit learning. The neural dynamics identified thus far do not fully meet expectations derived from traditional models of the structure of habits, and the behavioral measures of habits that we have made also are not fully aligned with these models. We explore these new clues as opportunities to refine an understanding of habits. PMID:24574988

  9. Model investigation overthrows assumptions of watershed research

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2012-04-01

    A 2009 study revealed serious flaws in a standard technique used by hydrological researchers to understand how changes in watershed land use affect stream flow behaviors, such as peak flows. The study caused academics and government agencies alike to rethink decades of watershed research and prompted Kuraś et al. to reinvestigate a number of long-standing assumptions in watershed research using a complex and well-validated computer model that accounts for a range of internal watershed dynamics and hydrologic processes. For the test site at 241 Creek in British Columbia, Canada, the authors found not only that deforestation increased the severity of floods but also that it had a scaling influence on both the magnitudes and frequencies of the floods. The model showed that the larger the flood, the more its magnitude was amplified by deforestation, with 10-to 100-year-return-period floods increasing in size by 9%-25%. Following a simulated removal of half of the watershed's trees, the authors found that 10-year-return-period floods occurred twice as often, while 100-year-return-period events became 5-6.7 times more frequent. This proportional relationship between the increase in flood magnitudes and frequencies following deforestation and the size of the flood runs counter to the prevailing wisdom in hydrological science.

  10. The effects of inquiry based ecopedagogy model on pre-service physics teachers' motivation and achievement in environmental physics instruction

    NASA Astrophysics Data System (ADS)

    Napitupulu, Nur Dewi; Munandar, Achmad

    2017-05-01

    —Motivation plays a crucial role in learning. Motivation energizes the behavior of the individual. It also directs the behavior towards specific goals. It helps students acquire knowledge, increase initiation, persist in activities, improve achievement, and develop a sense of discipline. The purpose of this study was to investigate the effects on the achievement and motivation of pre-service teacher of the Inquiry based ecopedagogy (In-EcoP) learning process applied to environmental physics instruction. The motivation adapted to Keller's four dimensions, namely attention, relevance, confidence and satisfaction. The study involved 66 students which are divided into two classes of an environmental physics instruction. The first class used the traditional lecture format while the In-EcoP model was used in the second. The research data were obtained through the environmental physics concept test and motivation questionnaire. The data analysis was conducted using a quantitative study approach and involved a motivational survey and an academic achievement test. It was found that the experimental group students were achieve more than the students in the control group. An increase in motivation and academic achievement of the students in the experimental group was identified as well. This research demonstrates the effectiveness of the In-EcoP model for enhancing pre-service teacher motivation and academic achievement in environmental physics instruction.

  11. Investigating the applicability of activity-based quantum mechanics in a few high school physics classrooms

    NASA Astrophysics Data System (ADS)

    Escalada, Lawrence Todd

    Quantum physics is not traditionally introduced in high school physics courses because of the level of abstraction and mathematical formalism associated with the subject. As part of the Visual Quantum Mechanics project, activity-based instructional units have been developed that introduce quantum principles to students who have limited backgrounds in physics and mathematics. This study investigates the applicability of one unit, Solids & Light, that introduces quantum principles within the context of learning about light emitting diodes. An observation protocol, attitude surveys, and questionnaires were used to examine the implementation of materials and student-teacher interactions in various secondary physics classrooms. Aspects of Solids & Light including the use of hands-on activities, interactive computer programs, inexpensive materials, and the focus on conceptual understanding were very applicable in the various physics classrooms observed. Both teachers and students gave these instructional strategies favorable ratings in motivating students to make observations and to learn. These ratings were not significantly affected by gender or students, attitudes towards physics or computers. Solid's & Light was applicable in terms of content and teaching style for some teachers. However, a mismatch of teaching styles between some instructors and the unit posed some problems in determining applicability. Observations indicated that some instructors were not able to utilize the exploratory instructional strategy of Solid's & Light. Thus, Solids & Light must include additional support necessary to make the instructor comfortable with the subject matter and pedagogical style. With these revisions, Solids & Light, will have all the key components to make its implementation in a high school physics classroom a successful one.

  12. Investigation of changes in psycho-physiological parameters evoked by short duration, intensive physical stress.

    PubMed

    Németh, E; Bretz, K J; Sótonyi, P; Bretz, Károly; Horváth, T; Tihanyi, J; Zima, E; Barna, T

    2013-12-01

    The aim of our study was to investigate changes in psycho-physiological parameters evoked by short duration, intensive physical stress on university students practicing judo at different intensities and timely manner. Stability of posture, muscle strength (hand force exertions), attention concentration (choice reaction time), cardiac parameters, (ECG, heart rate, heart rate variability), and oxygen saturation were measured, cardiac state and stress index were computed before and after the physical stress. The actual psychic state of the subjects was evaluated using the Spielberger's STPI-H Y-1 test which determined anxiety, curiosity, anger and depression level. Analysis of psychometric and physiologic parameters indicated significant correlations, among others, between force and cardiac stress (-), force and depression (-), anxiety and errors in actions (+), cardiac state and errors in action (-), cardiac state and depression (-). Paired samples tests showed the influence of intensive physical stress within groups of students, and independent samples tests made it possible to evaluate the power of medical and sport students, performing physical training at a significantly higher level than it is usual among the medical students. Our results proved that higher level physical training influences the psychic state advantageously, limits increases in cardiac stress level, and decreases susceptibility to anxiety and depression.

  13. Investigation of environmental physical parameters and processes complementing the search for signatures of life

    NASA Astrophysics Data System (ADS)

    Richter, L.; Horneck, G.; Kochan, H.; Rabbow, E.; Rettberg, P.; Ulamec, S.

    In general, the search for signatures of life on other planets follows different lines: one is to study life in extreme natural environments on the Earth, another one is to perform laboratory experiments under simulated natural conditions in order define the limits for formation and survival of life, and finally space missions to perform in situ measurements on planetary surfaces outside the Earth to look for indicators of extinct or extant life. For the case of the planet Mars, relevant surface conditions are roughly known from orbiter as well as lander missions. In an extrapolation of terrestrial conditions, laboratory studies are conducted on terrestrial biota from extreme environments under various simulated planetary surface conditions in order to investigate general biological survivability as a function of physical and chemical parameters (radiation, UV flux, atmosphere, temperature, humidity, soil properties including mineralogy and toxicity, etc.). This way, physical parameters and processes acting on planetary bodies and their interrelations are studied in parallel with the search for surviving biota. Several suitable test chambers for physical and for biological investigations of this type are available at DLR Cologne. Ultimately, the same physical quantities should be measured concurrently with biological measurements during future planetary landing missions searching for signatures of life. The general question, however, remains whether life on Earth shows any biochemical resemblance with hypothetical life on ancient or modern Mars.

  14. Geometric investigations of a vorticity model equation

    NASA Astrophysics Data System (ADS)

    Bauer, Martin; Kolev, Boris; Preston, Stephen C.

    2016-01-01

    This article consists of a detailed geometric study of the one-dimensional vorticity model equation which is a particular case of the generalized Constantin-Lax-Majda equation. Wunsch showed that this equation is the Euler-Arnold equation on Diff (S1) when the latter is endowed with the right-invariant homogeneous H ˙ 1 / 2-metric. In this article we prove that the exponential map of this Riemannian metric is not Fredholm and that the sectional curvature is locally unbounded. Furthermore, we prove a Beale-Kato-Majda-type blow-up criterion, which we then use to demonstrate a link to our non-Fredholmness result. Finally, we extend a blow-up result of Castro-Córdoba to the periodic case and to a much wider class of initial conditions, using a new generalization of an inequality for Hilbert transforms due to Córdoba-Córdoba.

  15. Problems with heterogeneity in physically based agricultural catchment models

    NASA Astrophysics Data System (ADS)

    Hansen, Jeppe Rølmer; Refsgaard, Jens Christian; Hansen, Søren; Ernstsen, Vibeke

    2007-08-01

    SummaryLumped conceptual rainfall-runoff models and physically based distributed models are being used successfully for simulating daily discharge at catchment scale. Physically based models are more desirable for simulation of the fate of agrochemicals (e.g. nitrate) because they rely on physical equations for flow and transport. The literature shows that the average response (e.g. percolation and leaching) at field scale can be simulated successfully by using effective or standard values in the parameterisation of these models. However, in areas characterised by a high degree of spatial variability the physically based models sometimes fail to simulate the discharge dynamics at catchment scale properly possibly due to the lack of representation of sub-grid variability. This paper presents an agricultural physically based distributed model concept which included 3561 combinations of root zone simulations of percolation and leaching that was distributed within a 622 km 2 catchment according to land use, climate, soil types, etc. This was thought to account for all heterogeneity within the catchment but did not. It was shown that a much simpler model with less than 100 combinations of root zone calculations partially including important variability at the catchment scale could simulate discharge equally well and in some cases better than the complex one. The most important parameter heterogeneity to include in the conceptualisation step apparently was sub-grid variation of soil physical parameters and variability of crop growth. The variation of crop growth was forced by restricting the rooting depth which potentially lumped other heterogeneities into this property. The results also suggest that the groundwater table that constitutes the lower boundary condition in the unsaturated zone is another important factor. However, this was difficult to examine because of the modelling approach that did not feature feedback from the saturated to the unsaturated zone. A list

  16. The Nature and Role of Physical Models in Enhancing Sixth Grade Students' Mental Models of Groundwater and Groundwater Processes

    ERIC Educational Resources Information Center

    Duffy, Debra Lynne Foster

    2012-01-01

    Through a non-experimental descriptive and comparative mixed-methods approach, this study investigated the experiences of sixth grade earth science students with groundwater physical models through an extended SE learning cycle format. The data collection was based on a series of quantitative and qualitative research tools intended to investigate…

  17. The Nature and Role of Physical Models in Enhancing Sixth Grade Students' Mental Models of Groundwater and Groundwater Processes

    ERIC Educational Resources Information Center

    Duffy, Debra Lynne Foster

    2012-01-01

    Through a non-experimental descriptive and comparative mixed-methods approach, this study investigated the experiences of sixth grade earth science students with groundwater physical models through an extended SE learning cycle format. The data collection was based on a series of quantitative and qualitative research tools intended to investigate…

  18. Coarse-grained, foldable, physical model of the polypeptide chain

    PubMed Central

    Chakraborty, Promita; Zuckermann, Ronald N.

    2013-01-01

    Although nonflexible, scaled molecular models like Pauling–Corey’s and its descendants have made significant contributions in structural biology research and pedagogy, recent technical advances in 3D printing and electronics make it possible to go one step further in designing physical models of biomacromolecules: to make them conformationally dynamic. We report here the design, construction, and validation of a flexible, scaled, physical model of the polypeptide chain, which accurately reproduces the bond rotational degrees of freedom in the peptide backbone. The coarse-grained backbone model consists of repeating amide and α-carbon units, connected by mechanical bonds (corresponding to φ and ψ) that include realistic barriers to rotation that closely approximate those found at the molecular scale. Longer-range hydrogen-bonding interactions are also incorporated, allowing the chain to readily fold into stable secondary structures. The model is easily constructed with readily obtainable parts and promises to be a tremendous educational aid to the intuitive understanding of chain folding as the basis for macromolecular structure. Furthermore, this physical model can serve as the basis for linking tangible biomacromolecular models directly to the vast array of existing computational tools to provide an enhanced and interactive human–computer interface. PMID:23898168

  19. A prospective investigation of the relationships among sleep quality, physical symptoms, and depressive symptoms during pregnancy.

    PubMed

    Kamysheva, Ekaterina; Skouteris, Helen; Wertheim, Eleanor H; Paxton, Susan J; Milgrom, Jeannette

    2010-06-01

    The aim of this study was to examine the prospective relationship between pregnancy physical discomforts experienced during the second trimester and late pregnancy depressive symptoms, as well as the mediating effect of sleep quality on antenatal depressive symptomatology. Healthy pregnant women (N=257) completed the Physical Symptoms Questionnaire, the Beck Depression Inventory, and the Pittsburgh Sleep Inventory at early-mid second trimester, and then again at late third trimester. Physical symptoms and sleep quality at the first time point were both correlated moderately with depressive symptoms at late pregnancy. Discomfort associated with physical symptoms was a better predictor of depressive symptoms than Frequency of symptoms, although a score combining Frequency, Discomfort and Effect of symptoms on life was the strongest predictor of depressive symptoms. Results of the hierarchical regression analyses of the mediation model indicated that physical symptoms at early-mid second trimester predicted depressive symptoms in the last trimester both directly, and via poor sleep quality (prospectively), which mediated the relationship. The clinical implications of these findings for antenatal care are discussed. Copyright 2009 Elsevier B.V. All rights reserved.

  20. An Investigation of Item Fit Statistics for Mixed IRT Models

    ERIC Educational Resources Information Center

    Chon, Kyong Hee

    2009-01-01

    The purpose of this study was to investigate procedures for assessing model fit of IRT models for mixed format data. In this study, various IRT model combinations were fitted to data containing both dichotomous and polytomous item responses, and the suitability of the chosen model mixtures was evaluated based on a number of model fit procedures.…

  1. An Investigation of Goodness of Model Data Fit

    ERIC Educational Resources Information Center

    Onder, Ismail

    2007-01-01

    IRT models' advantages can only be realized when the model fits the data set of interest. Therefore, this study aimed to investigate which IRT model will provide the best fit to the data obtained from OZDEBYR OSS 2004 D-II Exam Science Test. In goodness-of-fit analysis, first the model assumptions and then the expected model features were checked.…

  2. An Investigation of Goodness of Model Data Fit

    ERIC Educational Resources Information Center

    Onder, Ismail

    2007-01-01

    IRT models' advantages can only be realized when the model fits the data set of interest. Therefore, this study aimed to investigate which IRT model will provide the best fit to the data obtained from OZDEBYR OSS 2004 D-II Exam Science Test. In goodness-of-fit analysis, first the model assumptions and then the expected model features were checked.…

  3. Towards gender equity in physics in India: Initiatives, investigations, and questions

    NASA Astrophysics Data System (ADS)

    Shastri, P.; Kurup, A.; Resmi, L.; Ramaswamy, R.; Ubale, S.; Bagchi, S.; Rao, S.; Narasimhan, S.

    2015-12-01

    Initiatives towards gender parity in the sciences in India have occurred both at national, governmental levels and at local, institutional levels. A gender gap persists in physics, but data suggest that this gap is due neither to lack of interest in science nor to a lack of career goals in science among girls. We outline investigations that are important to pursue and recommendations that build on the existing science interest and the impact of initiatives so far.

  4. Physical Property Investigation of Two Recently Marketed Resin Composite Restorative Materials

    DTIC Science & Technology

    2015-06-18

    Marketed Resin Composite Restorative Materials 7. Intended publication/meeting: International Association of Dental Research Annual Meeting 8...Marketed Resin Composite Restorative Materials Major Marcus P. Kropf APPROVED; Colo71 Howard W. Roberts Date APPROVED: Col Drew W. Fallis Dean, Air... Composite  Restorative  Materials   Marcus  P.  Kropf   Physical  Property  Investigation  of  Two  Recently-­‐Marketed   Resin

  5. Filamentous Phages As a Model System in Soft Matter Physics

    PubMed Central

    Dogic, Zvonimir

    2016-01-01

    Filamentous phages have unique physical properties, such as uniform particle lengths, that are not found in other model systems of rod-like colloidal particles. Consequently, suspensions of such phages provided powerful model systems that have advanced our understanding of soft matter physics in general and liquid crystals in particular. We described some of these advances. In particular we briefly summarize how suspensions of filamentous phages have provided valuable insight into the field of colloidal liquid crystals. We also describe recent experiments on filamentous phages that have elucidated a robust pathway for assembly of 2D membrane-like materials. Finally, we outline unique structural properties of filamentous phages that have so far remained largely unexplored yet have the potential to further advance soft matter physics and material science. PMID:27446051

  6. Filamentous Phages As a Model System in Soft Matter Physics.

    PubMed

    Dogic, Zvonimir

    2016-01-01

    Filamentous phages have unique physical properties, such as uniform particle lengths, that are not found in other model systems of rod-like colloidal particles. Consequently, suspensions of such phages provided powerful model systems that have advanced our understanding of soft matter physics in general and liquid crystals in particular. We described some of these advances. In particular we briefly summarize how suspensions of filamentous phages have provided valuable insight into the field of colloidal liquid crystals. We also describe recent experiments on filamentous phages that have elucidated a robust pathway for assembly of 2D membrane-like materials. Finally, we outline unique structural properties of filamentous phages that have so far remained largely unexplored yet have the potential to further advance soft matter physics and material science.

  7. Compressive sensing as a paradigm for building physics models

    NASA Astrophysics Data System (ADS)

    Nelson, Lance J.; Hart, Gus L. W.; Zhou, Fei; Ozoliņš, Vidvuds

    2013-01-01

    The widely accepted intuition that the important properties of solids are determined by a few key variables underpins many methods in physics. Though this reductionist paradigm is applicable in many physical problems, its utility can be limited because the intuition for identifying the key variables often does not exist or is difficult to develop. Machine learning algorithms (genetic programming, neural networks, Bayesian methods, etc.) attempt to eliminate the a priori need for such intuition but often do so with increased computational burden and human time. A recently developed technique in the field of signal processing, compressive sensing (CS), provides a simple, general, and efficient way of finding the key descriptive variables. CS is a powerful paradigm for model building; we show that its models are more physical and predict more accurately than current state-of-the-art approaches and can be constructed at a fraction of the computational cost and user effort.

  8. A comprehensive physics-based model encompassing variable surface resistance and underlying physics of ionic polymer-metal composite actuators

    NASA Astrophysics Data System (ADS)

    Shen, Qi; Palmre, Viljar; Stalbaum, Tyler; Kim, Kwang J.

    2015-09-01

    The ionic polymer-metal composite (IPMC) is an emerging smart material in actuation and sensing applications, such as artificial muscles, underwater actuators, and advanced medical devices. However, the effect of the change in surface electrode properties on the actuating of IPMC has not been well studied. To address this problem, we theoretically predict and experimentally investigate the dynamic electro-mechanical response of the IPMC thin-strip actuator. A model of the IPMC actuator is proposed based on the Poisson-Nernst-Planck equations for ion transport and charge dynamics in the polymer membrane, while a physical model for the change of surface resistance of the electrodes of the IPMC due to deformation is also incorporated. By incorporating these two models, a complete, dynamic, physics-based model for IPMC actuators is presented. To verify the model, IPMC samples were prepared and experiments were conducted. The results show that the theoretical model can accurately predict the actuating performance of IPMC actuators over a range of dynamic conditions. Additionally, the charge dynamics inside the polymer during the oscillation of the IPMC is presented. It is also shown that the charge at the boundary mainly affects the induced stress of the IPMC. The current study is beneficial for the comprehensive understanding of the surface electrode effect on the performance of IPMC actuators.

  9. Electromagnetic, seismic and petro-physical investigations of the lithosphere-asthenosphere boundary in central Tibet

    NASA Astrophysics Data System (ADS)

    Vozar, J.; Fullea, J.; Jones, A. G.; Agius, M. R.; Lebedev, S.

    2011-12-01

    Combined seismological and electromagnetic investigations of the lithosphere and underlying asthenosphere have the potential to yield superior inferences than using either one on its own. Central Tibet offers an excellent natural laboratory for testing such approaches, given the high quality seismological and magnetotelluric (MT) data available as a consequence of INDEPTH studies. In particular, the presence and lateral and vertical extent of the Indian lithosphere beneath Tibet is highly debated. Integrated petrological-geophysical modeling of MT and surface-wave data, which are differently sensitive to temperature and composition, allows us to reduce the uncertainties associated with modeling these two data sets independently, as commonly undertaken. For the MT data, we use selected distortion-corrected MT transfer functions, from INDEPTH Phase III line 500 across central Tibet for 1D modeling. The selected data fit well the 1D assumption and exhibit large penetration depth. Our deep resistivity models can be classified into two different groups: i) the Lhasa Terrane and ii) the Qiangtang Terrane. For the Lhasa Terrane group, the models show the existence of two high conductive layers localized at depths of 60-80 km and more than 200 km, whereas for the Qiangtang Terrane these conductive layers appears to be occur at shallower depths, namely 30-50 km and 120 km depth respectively. Our dispersion curves for Rayleigh and Love surface waves were measured using seismograms recorded by stations of INDEPTH and PASSCAL experiments. Dispersion curves for central Lhasa and Qiangtang terranes show similarly low phase velocities at periods sampling the thick crust beneath the regions, but differ at periods sampling the mantle. Inverting the dispersion data for 1D, radially-anisotropic Vs profiles, we find that beneath central Qiangtang terrane shear velocity is lower than the global average down to 75 km below the Moho, indicating relatively high temperatures, whereas

  10. Theoretical investigations of the physical properties of zircon-type YVO{sub 4}

    SciTech Connect

    Huang Zuocai; Feng Jing; Pan Wei

    2012-01-15

    The crystal structure, electronic properties, elastic properties, hardness and thermodynamic properties of the laser host material zircon-type YVO{sub 4} are studied using the pseudopotential plane wave method within the local density approximation (LDA) and generalized gradient approximation (GGA). The calculated ground state values such as lattice parameter, bulk modulus and its pressure derivative, the band structure and densities of states were in favorable agreement with previous works and the existed experimental data. The elastic constants C{sub ij}, the aggregate elastic moduli (B, G, E), Poisson's ratio and elastic anisotropy have been investigated. In YVO{sub 4}, V-O bonds with shorter bond length and larger Mulliken population make great contribution to hardness than Y-O bonds. Using quasi-harmonic Debye model considering the phonon effects, bulk modulus, heat capacity and thermal expansion coefficient of YVO{sub 4} are calculated within a range of 0-6 GPa and 0-1200 K. - Graphical Abstract: (a) Directional dependence of Young's modulus in zircon-type YVO{sub 4} and (b) projections of the directional dependent Young's modulus in different planes for zircon-type YVO{sub 4}. The units are in GPa. Highlights: Black-Right-Pointing-Pointer This paper systematically studied the physical properties of zircon-type YVO{sub 4} from first-principles calculations. Black-Right-Pointing-Pointer Zircon-type YVO{sub 4} is mechanically stable and it is ductile for B/G>1.75 and v>0.26. Black-Right-Pointing-Pointer Universal elastic anisotropy index A{sup U} for zircon-type YVO{sub 4} is 2.41, so YVO{sub 4} is anisotropic. Black-Right-Pointing-Pointer V-O bonds with shorter bond length and larger Mulliken population make greater contribution to the hardness of YVO{sub 4}.

  11. A physics investigation of deadtime losses in neutron counting at low rates with Cf252

    SciTech Connect

    Evans, Louise G; Croft, Stephen

    2009-01-01

    {sup 252}Cf spontaneous fission sources are used for the characterization of neutron counters and the determination of calibration parameters; including both neutron coincidence counting (NCC) and neutron multiplicity deadtime (DT) parameters. Even at low event rates, temporally-correlated neutron counting using {sup 252}Cf suffers a deadtime effect. Meaning that in contrast to counting a random neutron source (e.g. AmLi to a close approximation), DT losses do not vanish in the low rate limit. This is because neutrons are emitted from spontaneous fission events in time-correlated 'bursts', and are detected over a short period commensurate with their lifetime in the detector (characterized by the system die-away time, {tau}). Thus, even when detected neutron events from different spontaneous fissions are unlikely to overlap in time, neutron events within the detected 'burst' are subject to intrinsic DT losses. Intrinsic DT losses for dilute Pu will be lower since the multiplicity distribution is softer, but real items also experience self-multiplication which can increase the 'size' of the bursts. Traditional NCC DT correction methods do not include the intrinsic (within burst) losses. We have proposed new forms of the traditional NCC Singles and Doubles DT correction factors. In this work, we apply Monte Carlo neutron pulse train analysis to investigate the functional form of the deadtime correction factors for an updating deadtime. Modeling is based on a high efficiency {sup 3}He neutron counter with short die-away time, representing an ideal {sup 3}He based detection system. The physics of dead time losses at low rates is explored and presented. It is observed that new forms are applicable and offer more accurate correction than the traditional forms.

  12. The Effectiveness of Physical Models in Teaching Anatomy: A Meta-Analysis of Comparative Studies

    ERIC Educational Resources Information Center

    Yammine, Kaissar; Violato, Claudio

    2016-01-01

    There are various educational methods used in anatomy teaching. While three dimensional (3D) visualization technologies are gaining ground due to their ever-increasing realism, reports investigating physical models as a low-cost 3D traditional method are still the subject of considerable interest. The aim of this meta-analysis is to quantitatively…

  13. Physical and Interpersonal Attractiveness of the Model and Imitation in Adults.

    ERIC Educational Resources Information Center

    Adams, Gerald R.; LaVoie, Joseph C.

    The effects of physical attractiveness, warmth, and sex of an adult model on imitation behavior of adult males and females were investigated. Subjects were randomly paired with confederates of low or high facial attractiveness who interacted with the subject in a cold-unfriendly or warm-friendly manner. The imitation task involved the confederate…

  14. The Effectiveness of Physical Models in Teaching Anatomy: A Meta-Analysis of Comparative Studies

    ERIC Educational Resources Information Center

    Yammine, Kaissar; Violato, Claudio

    2016-01-01

    There are various educational methods used in anatomy teaching. While three dimensional (3D) visualization technologies are gaining ground due to their ever-increasing realism, reports investigating physical models as a low-cost 3D traditional method are still the subject of considerable interest. The aim of this meta-analysis is to quantitatively…

  15. Effectiveness of the Sport Education Fitness Model on Fitness Levels, Knowledge, and Physical Activity

    ERIC Educational Resources Information Center

    Pritchard, Tony; Hansen, Andrew; Scarboro, Shot; Melnic, Irina

    2015-01-01

    The purpose of this study was to investigate changes in fitness levels, content knowledge, physical activity levels, and participants' perceptions following the implementation of the sport education fitness model (SEFM) at a high school. Thirty-two high school students participated in 20 lessons using the SEFM. Aerobic capacity, muscular…

  16. Effectiveness of the Sport Education Fitness Model on Fitness Levels, Knowledge, and Physical Activity

    ERIC Educational Resources Information Center

    Pritchard, Tony; Hansen, Andrew; Scarboro, Shot; Melnic, Irina

    2015-01-01

    The purpose of this study was to investigate changes in fitness levels, content knowledge, physical activity levels, and participants' perceptions following the implementation of the sport education fitness model (SEFM) at a high school. Thirty-two high school students participated in 20 lessons using the SEFM. Aerobic capacity, muscular…

  17. The Implementation of Models-Based Practice in Physical Education through Action Research

    ERIC Educational Resources Information Center

    Casey, Ashley; Dyson, Ben

    2009-01-01

    The purpose of this study was to explore the use of action research as a framework to investigate cooperative learning and tactical games as instructional models in physical education (PE). The teacher/researcher taught a tennis unit using a combination of Cooperative Learning and Teaching Games for Understanding to three classes of boys aged…

  18. The Implementation of Models-Based Practice in Physical Education through Action Research

    ERIC Educational Resources Information Center

    Casey, Ashley; Dyson, Ben

    2009-01-01

    The purpose of this study was to explore the use of action research as a framework to investigate cooperative learning and tactical games as instructional models in physical education (PE). The teacher/researcher taught a tennis unit using a combination of Cooperative Learning and Teaching Games for Understanding to three classes of boys aged…

  19. Modeling the Stress Complexities of Teaching and Learning of School Physics in Nigeria

    ERIC Educational Resources Information Center

    Emetere, Moses E.

    2014-01-01

    This study was designed to investigate the validity of the stress complexity model (SCM) to teaching and learning of school physics in Abuja municipal area council of Abuja, North. About two hundred students were randomly selected by a simple random sampling technique from some schools within the Abuja municipal area council. A survey research…

  20. Mathematical modeling of physical-chemical wastewater treatment plant

    SciTech Connect

    Torruellas, E.D.

    1987-01-01

    The scheme of treatment modeled includes processes such as coagulation, flocculation, sedimentation, sand filtration, adsorption on granular activated carbon, and surge storage. Sludge treatment processes such as gravity thickening, vacuum filter dewatering, and hauling and disposal were also simulated. The primary objective of this work is to demonstrate that an optimization scheme can be used to determine the minimum total cost of a complex physical-chemical treatment system with models representing the individual unit processes. A method for determining the minimum cost design of a physical-chemical treatment plant is presented. The method utilizes an existing search technique (Box complex algorithm) to optimize a non-linear cost function for the physical-chemical processes. Thus, the physical-chemical treatment plant design is formulated as an optimization problem with non-linear cost functions and realistic mathematical models for each of its constituent unit processes. The level of cost resolution adopted derives from a series of economic models developed which basically make a Present Worth Analysis of each unit within the system. The economic data are based mostly on updated cost information obtained from Environmental Protection Agency Technology Transfer Manuals. Among the benefits directly derived from this study are the following: optimum economic design and operation of a typical physical-chemical treatment plant, simplified and directly oriented pilot plant studies, and the cost savings associated with it. Also, the formulation of a relatively new design concept is developed which underlines the need of the simultaneous consideration of all the components of a physical-chemical treatment plant for the most economic design.