Science.gov

Sample records for l2-5 experiment comparison

  1. The BEMUSE Programme: Results of the First Part Concerning the LOFT L2-5 Test

    SciTech Connect

    Crecy, Agnes de; Bazin, Pascal; D'Auria, Francesco; Petruzzi, Alessandro; Ryu, Yong-Ho

    2006-07-01

    This paper is aimed at describing results of the first part of the BEMUSE (Best Estimate Methods - Uncertainty and Sensitivity Evaluation) programme. The purpose of BEMUSE is the comparison of best-estimate calculations, followed by the comparison of uncertainty and sensitivity analyses for a Large Break Loss of Coolant Accident (LB-LOCA). The first part of the programme is devoted to the study of the LOFT L2-5 experiment. After a general presentation of the programme, which implies more than ten participants, this paper describes the qualification process and the results of the best-estimate calculations. The results are significantly less dispersed than those of the ISP-13, concerning already LOFT L2-5 more than 20 years ago. Then, it presents extensively the methods and the results of uncertainty and sensitivity analyses. All the participants, apart from the University of Pisa with the CIAU method, use a fully probabilistic approach, based on Wilks' formula. However, differences appear for the choice of the uncertain input parameters to be considered and for their associated range of variation. Sensitivity analysis is performed with regression techniques, and the results are also compared. As a conclusion, main lessons learnt from BEMUSE and recommendations are presented. (authors)

  2. Group membership and everyday social comparison experiences

    PubMed Central

    SMITH, HEATHER J.; LEACH, COLIN W.

    2006-01-01

    In two everyday experience studies, we examined the degree to which everyday social comparisons are framed by group membership. In the first study, 30 undergraduates attending a public university in the United States completed short questionnaires about their social comparison experiences whenever they were signalled. In the second study, 34 ethnic minority undergraduates from the same university completed similar questionnaires about their social comparison experiences. Across both studies, comparisons in which participants viewed themselves as an ingroup member in comparison to an outgroup comprised less than 10% of the comparison experiences reported by participants. However, minorities in the second study who reported closer identification with their ethnic group reported more comparison experiences in which they mentioned their own or the comparison target's ethnicity. PMID:16691290

  3. 33alloy: comparison between experiment and simulation

    SciTech Connect

    Kramer, M J; Mendelev, M I; Asta, M

    2014-04-22

    We report data on the structure of liquid Al and an Al67Mg33 alloy obtained from state-of-the-art X-ray diffraction experiments and ab initio molecular dynamics (AIMD) simulations. To facilitate a direct comparison between these data, we develop a method to elongate the AIMD pair correlation function in order to obtain reliable AIMD structure factors. The comparison reveals an appreciable level of discrepancy between experimental and AIMD liquid structures, with the latter being consistently more ordered than the former at the same temperature. The discrepancy noted in this study is estimated to have significant implications for simulation-based calculations of liquid transport properties and solid–liquid interface kinetic properties.

  4. Comparison of bioseparation methods for microgravity experiments

    NASA Technical Reports Server (NTRS)

    Morrison, Dennis R.; Cohly, Hari H. P.; Rodkey, L. Scott; Barlow, Grant H.; Hymer, Wesley C.

    1988-01-01

    The efficiency of the 1-g version of the continuous-flow electrophoresis (CFE) system flown on Space Shuttle missions is compared with the efficiency of a commercial CFE for separating living cells (human kidney, liver, and pituitary-gland cells and T-lymphocytes). In addition, the CFE system and a reciprocal isoelectric focusing (RIEF) system are compared with respect to protein pyrification efficiency. Correlations were made among electrophoretic mobilities (EPMs), secretory functions of cells, and input sample concentrations. A significant reduction in mean and range EPM was observed when input sample concentrations exceeded a low threshohold. This effect was not observed in microgravity experiments conducted at sample concentrations three times greater than the threshold for the controls. Comparison of CFE and RIEF methods showed that there are apparent advantages for each method depending on the product. For example, RIEF purification of urokinase removed more protein impurities, but focused the enzyme at a pH different than the enzyme's known isoelectric point.

  5. OpenMP Experiences and Comparisons

    NASA Technical Reports Server (NTRS)

    Nelson, Terry; Thigpen, William W. (Technical Monitor)

    2002-01-01

    The document discusses message passage interfaces (MPI), open message passage issues and parallelization. A comparison of the two vector platforms, C90 and SVlex is presented. Sections of the document are written in computer code.

  6. Cylinder expansion test and gas gun experiment comparison

    SciTech Connect

    Harrier, Danielle

    2016-06-30

    This is a summer internship presentation by the Hydro Working Group at Los Alamos National Laboratory (LANL) and goes into detail about their cylinder expansion test and gas gun experiment comparison. Specifically, the gas gun experiment is detailed along with applications, the cylinder expansion test is detailed along with applications, there is a comparison of the methods with pros and cons and limitations listed, the summer project is detailed, and future work is talked about.

  7. GASFLOW comparisons with bureau of mines experiments

    SciTech Connect

    Mueller, C.; Travis, J.R.

    1994-09-01

    At the request of the Department of Energy and Westinghouse Hanford Company, the Bureau of Mines has investigated the flammability of mixtures of hydrogen, ammonia, nitrous oxide, and air. The tests were performed in a spherical chamber under quiescent and turbulent conditions. This paper describes combustion calculations using the GASFLOW code and compares the calculated pressure ratios with experiments mentioned above. GASFLOW is a finite-volume computer code that solves the transient, three-dimensional, compressible fluid, Navier-Stokes equations with multiple species coupled with finite-rate chemical kinetics. The computational results show good agreement with the experimental data and confirm GASFLOW to be a valuable tool for evaluating the above combustion process.

  8. Disentangling forms of Lorentz violation with complementary clock comparison experiments

    SciTech Connect

    Altschul, Brett

    2009-03-15

    Atomic clock comparisons provide some of the most precise tests of Lorentz and CPT symmetries in the laboratory. With data from multiple such experiments using different nuclei, it is possible to constrain new regions of the parameter space for Lorentz violation. Relativistic effects in the nuclei allow us to disentangle forms of Lorentz violation which could not be separately measured in purely nonrelativistic experiments. The disentangled bounds in the neutron sectors are at the 10{sup -28} GeV level, far better than could be obtained with any other current technique.

  9. DSMC Simulations of Hypersonic Flows and Comparison With Experiments

    NASA Technical Reports Server (NTRS)

    Moss, James N.; Bird, Graeme A.; Markelov, Gennady N.

    2004-01-01

    This paper presents computational results obtained with the direct simulation Monte Carlo (DSMC) method for several biconic test cases in which shock interactions and flow separation-reattachment are key features of the flow. Recent ground-based experiments have been performed for several biconic configurations, and surface heating rate and pressure measurements have been proposed for code validation studies. The present focus is to expand on the current validating activities for a relatively new DSMC code called DS2V that Bird (second author) has developed. Comparisons with experiments and other computations help clarify the agreement currently being achieved between computations and experiments and to identify the range of measurement variability of the proposed validation data when benchmarked with respect to the current computations. For the test cases with significant vibrational nonequilibrium, the effect of the vibrational energy surface accommodation on heating and other quantities is demonstrated.

  10. Comparison of simulation with experiment in an RFQ

    SciTech Connect

    Boicourt, G.P.; Sander, O.R.; Wangler, T.P.

    1985-01-01

    The accelerator test stand (ATS) RFQ has provided an opportunity to compare the predictions of the RFQ beam-dynamics code PARMTEQ with actual operation of an RFQ. For this comparison, the code was adapted to simulate the measured operation parameters, which are somewhat different from those of the ideal design. A Monte Carlo code was written to provide input to PARMTEQ, based on measured input beam distributions. With these refinements, the code has given results that are in good agreement with measurements and has provided information leading to an explanation of an unexpected set of measurements. This paper describes the method used to generate a pseudo particle beam based on the measured transverse properties of the RFQ input beam and describes some of the comparisons between simulation and experiment. An explanation is provided for the energy-spectrum structure observed in the RFQ output beam during low-voltage operation. 3 refs., 7 figs.

  11. Experience with CANDID: Comparison algorithm for navigating digital image databases

    SciTech Connect

    Kelly, P.; Cannon, M.

    1994-10-01

    This paper presents results from the authors experience with CANDID (Comparison Algorithm for Navigating Digital Image Databases), which was designed to facilitate image retrieval by content using a query-by-example methodology. A global signature describing the texture, shape, or color content is first computed for every image stored in a database, and a normalized similarity measure between probability density functions of feature vectors is used to match signatures. This method can be used to retrieve images from a database that are similar to a user-provided example image. Results for three test applications are included.

  12. Initial NIF Shock Timing Experiments: Comparison with Simulation

    NASA Astrophysics Data System (ADS)

    Robey, H. F.; Celliers, P. M.; Boehly, T. R.; Datte, P. S.; Bowers, M. W.; Olson, R. E.; Munro, D. H.; Milovich, J. L.; Jones, O. S.; Nikroo, A.; Kroll, J. J.; Horner, J. B.; Hamza, A. V.; Bhandarkar, S. D.; Giraldez, E.; Castro, C.; Gibson, C. R.; Eggert, J. H.; Smith, R. F.; Park, H.-S.; Young, B. K.; Hsing, W. W.; Landen, O. L.; Meyerhofer, D. D.

    2010-11-01

    Initial experiments are underway to demonstrate the techniques required to tune the shock timing of capsule implosions on the National Ignition Facility (NIF). These experiments use a modified cryogenic hohlraum geometry designed to precisely match the performance of ignition hohlraums. The targets employ a re-entrant Au cone to provide optical access to the shocks as they propagate in the liquid deuterium-filled capsule interior. The strength and timing of the shocks is diagnosed with VISAR (Velocity Interferometer System for Any Reflector) and DANTE. The results of these measurements will be used to set the precision pulse shape for ignition capsule implosions to follow. Experimental results and comparisons with numerical simulation are presented.

  13. Beryllium atom reinvestigated: A comparison between theory and experiment

    NASA Astrophysics Data System (ADS)

    Mårtensson-Pendrill, Ann-Marie; Alexander, Steve A.; Adamowicz, Ludwik; Oliphant, Nevin; Olsen, Jeppe; Öster, Per; Quiney, Harry M.; Salomonson, Sten; Sundholm, Dage

    1991-04-01

    We compare the theoretical and experimental energies for the ground state of the beryllium atom and investigate possible sources for the small discrepancy of about 60 μhartrees found by Bunge [Phys. Rev. A 14, 1965 (1976); 17, 486(E) (1978)]. Indications that the correlation energy may be underestimated in Bunge's work have been confirmed by a recent, very extensive multiconfigurational Hartree-Fock (MCHF) calculation. We emphasize that the critical part of the comparison between theory and experiment is the sum of the first and second ionization energies-the third and fourth are known more accurately from theory-and present the theoretical results accordingly. Before a comparison with experimental results can be performed, corrections must be added to account for mass polarization, for the effect of relativity including the Breit interaction and for radiative effects. The previously unknown mass-polarization contribution to the first ionization energy has recently been determined experimentally. Relativity is most important for the 1s electrons and this effect was included in Bunge's work, whereas the relativistic effect on the correlation involving the 2s electrons was neglected. Here, these contributions have been calculated to leading order. A crude estimate of the contribution to the Lamb shift from the 2s electrons is also given. When the revised relativistic corrections are combined with recent results from a very extensive MCHF calculation, the discrepancy in the beryllium ground-state energy is reduced to (10+/-50)μ hartrees.

  14. Extension of nanoconfined DNA: Quantitative comparison between experiment and theory

    NASA Astrophysics Data System (ADS)

    Iarko, V.; Werner, E.; Nyberg, L. K.; Müller, V.; Fritzsche, J.; Ambjörnsson, T.; Beech, J. P.; Tegenfeldt, J. O.; Mehlig, K.; Westerlund, F.; Mehlig, B.

    2015-12-01

    The extension of DNA confined to nanochannels has been studied intensively and in detail. However, quantitative comparisons between experiments and model calculations are difficult because most theoretical predictions involve undetermined prefactors, and because the model parameters (contour length, Kuhn length, effective width) are difficult to compute reliably, leading to substantial uncertainties. Here we use a recent asymptotically exact theory for the DNA extension in the "extended de Gennes regime" that allows us to compare experimental results with theory. For this purpose, we performed experiments measuring the mean DNA extension and its standard deviation while varying the channel geometry, dye intercalation ratio, and ionic strength of the buffer. The experimental results agree very well with theory at high ionic strengths, indicating that the model parameters are reliable. At low ionic strengths, the agreement is less good. We discuss possible reasons. In principle, our approach allows us to measure the Kuhn length and the effective width of a single DNA molecule and more generally of semiflexible polymers in solution.

  15. Comparison Between Theory and Experiment for Wings at Supersonic Speeds

    NASA Technical Reports Server (NTRS)

    Vincenti, Walter G

    1951-01-01

    This paper presents a critical comparison made between experimental and theoretical results for the aerodynamic characteristics of wings at supersonic flight speeds. As a preliminary, a brief, nonmathematical review is given of the basic assumptions and general findings of supersonic wing theory in two and three dimensions. Published data from two-dimensional pressure-distribution tests are then used to illustrate the effects of fluid viscosity and to assess the accuracy of linear theory as compared with the more exact theories which are available in the two-dimensional case. Finally, an account is presented of an NACA study of the over-all force characteristics of three-dimensional wings at supersonic speed. In this study, the lift, pitching moment, and drag characteristics of several families of wings of varying plan form and section were measured in the wind tunnel and compared with values predicted by the three-dimensional linear theory. The regions of agreement and disagreement between experiment and theory are noted and discussed.

  16. A Comparison of Web-Based and Face-to-Face Functional Measurement Experiments

    ERIC Educational Resources Information Center

    Van Acker, Frederik; Theuns, Peter

    2010-01-01

    Information Integration Theory (IIT) is concerned with how people combine information into an overall judgment. A method is hereby presented to perform Functional Measurement (FM) experiments, the methodological counterpart of IIT, on the Web. In a comparison of Web-based FM experiments, face-to-face experiments, and computer-based experiments in…

  17. Comparison of fast neutron rates for the NEOS experiment

    NASA Astrophysics Data System (ADS)

    Ko, Y. J.; Jang, C. H.; Siyeon, Kim; Kim, J. Y.; Kim, H. S.; Seo, K. M.; Han, B. Y.; Sun, G. M.; Jeon, E. J.; Lee, Jaison; Lee, M. H.; Oh, Y. M.; Park, K. S.; Joo, K. K.; Kim, B. R.; Kim, H. J.; Lee, J. Y.; Kim, Y. D.; Park, H. K.; Park, H. S.

    2016-12-01

    The fast neutron rates are compared at the site of the NEOS (Neutrino Experiment Oscillation Short baseline) experiment, a short-baseline neutrino experiment located in a tendon gallery of a commercial nuclear power plant using a 0.78-liter liquid scintillator detector. A pulse shape discrimination technique is used to identify neutron signals. The measurements are performed during the nuclear reactor-on and -off periods, and the fast neutron rates are found to be consistent with each other. The fast neutron rate is also measured at an overground site with a negligible overburden and is found to be 100 times higher than that at the site of the NEOS experiment.

  18. Drift studies--comparison of field and wind tunnel experiments.

    PubMed

    Stadler, R; Regenauer, W

    2005-01-01

    Drift at pesticide application leads to a pollution of non-target crops, non-target species and surface water. Spray drift is influenced by many factors like environmental conditions, vegetation, technical conditions, and physical properties of the tank mixes and influenced by Chemicals. Field experiments to characterise spray drift effects with the risk of permanent changing weather conditions can be supported by wind tunnel experiments. Wind tunnel experiments do not lead to the same soil deposition curves like field experiments, but the ratio of drift reduction potential is comparable.

  19. Test Experience Effects in Longitudinal Comparisons of Adult Cognitive Functioning

    ERIC Educational Resources Information Center

    Salthouse, Timothy

    2015-01-01

    It is widely recognized that experience with cognitive tests can influence estimates of cognitive change. Prior research has estimated experience effects at the level of groups by comparing the performance of a group of participants tested for the second time with the performance of a different group of participants at the same age tested for the…

  20. Theory and Experiment of Multielement Airfoils: A Comparison

    NASA Technical Reports Server (NTRS)

    Czerwiec, Ryan; Edwards, J. R.; Rumsey, C. L.; Hassan, H. A.

    2000-01-01

    A detailed comparison of computed and measured pressure distributions, velocity profiles, transition onset, and Reynolds shear stresses for multi-element airfoils is presented. It is shown that the transitional k-zeta model, which is implemented into CFL3D, does a good job of predicting pressure distributions, transition onset, and velocity profiles with the exception of velocities in the slat wake region. Considering the fact that the hot wire used was not fine enough to resolve Reynolds stresses in the boundary layer, comparisons of turbulence stresses varied from good to fair. It is suggested that the effects of unsteadiness be thoroughly evaluated before more complicated transition/turbulence models are used. Further, it is concluded that the present work presents a viable and economical method for calculating laminar/transitional/turbuient flows over complex shapes without user interface.

  1. Comparison of two experiments on radiative neutron decay

    SciTech Connect

    Khafizov, R. U.; Tolokonnikov, S. V.; Solovei, V. A.; Kolhidashvili, M. R.

    2009-12-15

    Over 10 years ago we proposed an experiment on measuring the characteristics of radiative neutron decay in papers [1, 2]. At the same time we had published the theoretical spectrum of radiative gamma quanta, calculated within the framework of the electroweak interactions, on the basis of which we proposed the methodology for the future experiment [3, 4]. However, because we were denied beam time on the intensive cold neutron beam at ILL (Grenoble, France) for a number of years, we could only conduct the experiment in 2005 on the newly opened FRMII reactor of Technical University of Muenchen. The main result of this experiment was the discovery of radiative neutron decay and the measurement of its relative intensity B.R. = (3.2 {+-} 1.6) x 10{sup -3} with C.L. = 99.7% for radiative gamma quanta with energy over 35 kev [5, 6]. Over a year after our first announcement about the results of the conducted experiment, 'Nature' [7] published a letter asserting that its authors have also measured the branching ratio of radiative neutron decay B.R. = (3.13 {+-} 0.34) x 10{sup -3} with c.l. = 68% and gamma quanta energy from 15 to 340 kev. This article aims to compare these two experiments. It is shown that the use of strong magnetic fields in the NIST (Washington, USA) experiment methodology not only prevents any exact measurement of the branching ratio and identification of radiative neutron decay events, but also makes registration of ordinary neutron decay events impossible.

  2. A national comparison of biochemistry and molecular biology capstone experiences.

    PubMed

    Aguanno, Ann; Mertz, Pamela; Martin, Debra; Bell, Ellis

    2015-01-01

    Recognizing the increasingly integrative nature of the molecular life sciences, the American Society for Biochemistry and Molecular Biology (ASBMB) recommends that Biochemistry and Molecular Biology (BMB) programs develop curricula based on concepts, content, topics, and expected student outcomes, rather than courses. To that end, ASBMB conducted a series of regional workshops to build a BMB Concept Inventory containing validated assessment tools, based on foundational and discipline-specific knowledge and essential skills, for the community to use. A culminating activity, which integrates the educational experience, is often part of undergraduate molecular life science programs. These "capstone" experiences are commonly defined as an attempt to measure student ability to synthesize and integrate acquired knowledge. However, the format, implementation, and approach to outcome assessment of these experiences are quite varied across the nation. Here we report the results of a nation-wide survey on BMB capstone experiences and discuss this in the context of published reports about capstones and the findings of the workshops driving the development of the BMB Concept Inventory. Both the survey results and the published reports reveal that, although capstone practices do vary, certain formats for the experience are used more frequently and similarities in learning objectives were identified. The use of rubrics to measure student learning is also regularly reported, but details about these assessment instruments are sparse in the literature and were not a focus of our survey. Finally, we outline commonalities in the current practice of capstones and suggest the next steps needed to elucidate best practices.

  3. A Comparison of Metamodeling Techniques via Numerical Experiments

    NASA Technical Reports Server (NTRS)

    Crespo, Luis G.; Kenny, Sean P.; Giesy, Daniel P.

    2016-01-01

    This paper presents a comparative analysis of a few metamodeling techniques using numerical experiments for the single input-single output case. These experiments enable comparing the models' predictions with the phenomenon they are aiming to describe as more data is made available. These techniques include (i) prediction intervals associated with a least squares parameter estimate, (ii) Bayesian credible intervals, (iii) Gaussian process models, and (iv) interval predictor models. Aspects being compared are computational complexity, accuracy (i.e., the degree to which the resulting prediction conforms to the actual Data Generating Mechanism), reliability (i.e., the probability that new observations will fall inside the predicted interval), sensitivity to outliers, extrapolation properties, ease of use, and asymptotic behavior. The numerical experiments describe typical application scenarios that challenge the underlying assumptions supporting most metamodeling techniques.

  4. Experiments for comparison of small scale rainfall simulators

    NASA Astrophysics Data System (ADS)

    Iserloh, T.; Ries, J. B.

    2012-04-01

    Small scale portable rainfall simulators are an essential tool in research of recent process dynamics of soil erosion. Such rainfall simulators differ in design, rainfall intensities, rain spectra etc., impeding comparison of the results. Due to different research questions a standardisation of rainfall simulation is not in sight. Nevertheless, the data become progressively important for soil erosion modelling and therefore the basis for decision-makers in application-oriented erosion protection. The project aims at providing a criteria catalogue for estimation of the different simulators as well as the comparability of the results and a uniform calibration procedure for generated rainfall. Within the project "Comparability of simulation results of different rainfall simulators as input data for soil erosion modelling (Deutsche Forschungsgemeinschaft - DFG, Project No. Ri 835/6-1)" many rainfall simulators used by European research groups were compared. The artificially generated rainfall of the rainfall simulators at the Universities Basel, La Rioja, Malaga, Trier, Tübingen, Valencia, Wageningen, Zaragoza and at different Spanish CSIC-institutes (Almeria, Cordoba, Granada, Murcia, Zaragoza) were measured with the same methods (Laser Precipitation Monitor for drop spectra and rain collectors for spatial distribution). The data are very beneficial for improvements of simulators and comparison of simulators and results. Furthermore, they can be used for comparative studies with natural rainfall spectra. A broad range of rainfall data was measured (e.g. intensity: 30 - 149 mmh-1, Christiansen Coefficient for spatial rainfall distribution 61 - 98 %, mean drop diameter 0.375 - 5.0 mm, mean kinetic energy expenditure 25 - 1322 J m-2 h-1, mean kinetic energy per unit area and unit depth of rainfall 4 - 14 J m-2 mm-1). Similarities among the simulators could be found e.g. concerning drop size distributions (maximum drop numbers are reached within the two smallest drop

  5. An Enzymatic Clinical Chemistry Laboratory Experiment Incorporating an Introduction to Mathematical Method Comparison Techniques

    ERIC Educational Resources Information Center

    Duxbury, Mark

    2004-01-01

    An enzymatic laboratory experiment based on the analysis of serum is described that is suitable for students of clinical chemistry. The experiment incorporates an introduction to mathematical method-comparison techniques in which three different clinical glucose analysis methods are compared using linear regression and Bland-Altman difference…

  6. School Climate and the Experience of LGBT Students: A Comparison of the United States and Israel

    ERIC Educational Resources Information Center

    Pizmony-Levy, Oren; Kosciw, Joseph G.

    2016-01-01

    This article examines the school experience of lesbian, gay, bisexual, and transgender (LGBT) students in the United States and Israel. Through comparison of the sociocultural and edu-cational contexts, the authors assess whether school experience of LGBT students differs or operates similarly across countries. The authors use data from the…

  7. MISSE Thermal Control Materials with Comparison to Previous Flight Experiments

    NASA Technical Reports Server (NTRS)

    Finckenor, Miria; Pippin, H. Gary; Frey, George

    2008-01-01

    Many different passive thermal control materials were flown as part of the Materials on International Space Station Experiment (MISSE), including inorganic coatings, anodized aluminum, and multi-layer insulation materials. These and other material samples were exposed to the low Earth orbital environment of atomic oxygen, ultraviolet radiation, thermal cycling, and hard vacuum, though atomic oxygen exposure was limited for some samples. Materials flown on MISSE-1 and MISSE-2 were exposed to the space environment for nearly four years. Materials flown on MISSE-3, MISSE-4, and MISSE-5 were exposed to the space environment for one year. Solar absorptance, infrared emittance, and mass measurements indicate the durability of these materials to withstand the space environment. Effects of short duration versus long duration exposure on ISS are explored, as well as comparable data from previous flight experiments, such as the Passive Optical Sample Assembly (POSA), Optical Properties Monitor (OPM), and Long Duration Exposure Facility (LDEF).

  8. A Comparison of the SOCIT and DebriSat Experiments

    NASA Technical Reports Server (NTRS)

    Ausay, Erick; Blake, Brandon; Boyle, Colleen; Cornejo, Alex; Horn, Alexa; Palma, Kirsten; Pistella, Frank; Sato, Taishi; Todd, Naromi; Zimmerman, Jeffrey; Fitz-Coy, Norman; Liou, J.-C.; Sorge, Marlon; Huynh, Thomas; Opiela, John; Krisko, Paula H.; Cowardin, Heather

    2017-01-01

    This paper explores the differences between, and shares the lessons learned from, two hypervelocity impact experiments critical to the update of orbital debris environment models. The procedures and processes of the fourth Satellite Orbital Debris Characterization Impact Test (SOCIT) were analyzed and related to the ongoing DebriSat experiment. SOCIT was the first hypervelocity impact test designed specifically for satellites in Low Earth Orbit (LEO). It targeted a 1960's U.S. Navy satellite, from which data was obtained to update pre-existing NASA and DOD breakup models. DebriSat is a comprehensive update to these satellite breakup models- necessary since the material composition and design of satellites have evolved from the time of SOCIT. Specifically, DebriSat utilized carbon fiber, a composite not commonly used in satellites during the construction of the US Navy Transit satellite used in SOCIT. Although DebriSat is an ongoing activity, multiple points of difference are drawn between the two projects. Significantly, the hypervelocity tests were conducted with two distinct satellite models and test configurations, including projectile and chamber layout. While both hypervelocity tests utilized soft catch systems to minimize fragment damage to its post-impact shape, SOCIT only covered 65% of the projected area surrounding the satellite, whereas, DebriSat was completely surrounded cross-range and downrange by the foam panels to more completely collect fragments. Furthermore, utilizing lessons learned from SOCIT, DebriSat's post-impact processing varies in methodology (i.e., fragment collection, measurement, and characterization). For example, fragment sizes were manually determined during the SOCIT experiment, while DebriSat utilizes automated imaging systems for measuring fragments, maximizing repeatability while minimizing the potential for human error. In addition to exploring these variations in methodologies and processes, this paper also presents the

  9. Laser-Induced Ignition Modeling and Comparison with Experiments

    NASA Astrophysics Data System (ADS)

    Dors, Ivan; Qin, W.; Chen, Y.-L.; Parigger, C.; Lewis, J. W. L.

    2000-11-01

    We have studied experimentally the ignition resulting from optical breakdowns in mixtures of oxygen and the fuel ammonia induced by a 10 nanosecond pulsewidth laser for a time of hundreds of milliseconds using laser spectroscopy. In these studies, we have for the first time characterized the laser-induced plasma, the formation of the combustion radicals, the detonation wave, the flame front and the combustion process itself. The objective of the modeling is to understand the fluid dynamic and chemical kinetic effects following the nominal 10 ns laser pulse until 1 millisecond after laser breakdown. The calculated images match the experimentally recorded data sets and show spatial details covering volumes of 1/10000 cc to 1000 cc. The code was provided by CFD Research Corporation of Huntsville, Alabama, and was appropriately augmented to compute the observed phenomena. The fully developed computational model now includes a kinetic mechanism that implements plasma equilibrium kinetics in ionized regions, and non-equilibrium, multistep, finite rate reactions in non-ionized regions. The predicted fluid phenomena agree with various flow patterns characteristic of laser spark ignition as measured in the CLA laboratories. Comparison of calculated and measured OH and NH concentration will be presented.

  10. Shape stability of sonoluminescence bubbles: comparison of theory to experiments.

    PubMed

    Storey, B D

    2001-07-01

    Single bubble sonoluminescence (SBSL) is the brief flash of light emitted from a single, stable, acoustically forced bubble. In experiments, the maximum pressure amplitude with which a bubble may be forced is limited by considerations of spherical stability. The traditional linear stability analysis predicts a threshold for SBSL at a much lower pressure amplitude than experimental observations. This work shows that if one constructs an accurate model of the radial dynamics, the traditional linear stability analysis predicts a boundary that is in excellent agreement with experimental data.

  11. A numerical algorithm for endochronic plasticity and comparison with experiment

    NASA Technical Reports Server (NTRS)

    Valanis, K. C.; Fan, J.

    1985-01-01

    A numerical algorithm based on the finite element method of analysis of the boundary value problem in a continuum is presented, in the case where the plastic response of the material is given in the context of endochronic plasticity. The relevant constitutive equation is expressed in incremental form and plastic effects are accounted for by the method of an induced pseudo-force in the matrix equations. The results of the analysis are compared with observed values in the case of a plate with two symmetric notches and loaded longitudinally in its own plane. The agreement between theory and experiment is excellent.

  12. GASFLOW comparisons with the Bureau of Mines experiments

    SciTech Connect

    Mueller, C.; Travis, J.R.

    1994-12-31

    At the request of the U.S. Department of Energy and Westinghouse Hanford Company, the U.S. Bureau of Mines (BOM) (Pittsburgh Research Center, Pittsburgh, Pennsylvania) has investigated the flammable mixtures of hydrogen, ammonia, nitrous oxide, and air. The tests were performed in a 120-l, 61-cm (2-ft)-diam spherical chamber at ambient temperature and pressure under quiescent and turbulent conditions using both electric spark and pyrotechnic ignition sources. This paper describes combustion calculations with the GAS-FLOW code and compares the resulting pressure ratios with the aforementioned experiments. GASFLOW is a finite-volume computer code that solves the transient, three-dimensional, compressible fluid, Navier-Stokes equations with multiple species coupled with finite-rate chemical kinetics. This code was developed at Los Alamos National Laboratory as a best-estimate tool for predicting the transport, mixing, and combustion of hydrogen gas in nuclear reactor containments.

  13. Comparison of Theory and Experiment on Aeroacoustic Loads and Deflections

    NASA Astrophysics Data System (ADS)

    Campos, L. M. B. C.; Bourgine, A.; Bonomi, B.

    1999-01-01

    The correlation of acoustic pressure loads induced by a turbulent wake on a nearby structural panel is considered: this problem is relevant to the acoustic fatigue of aircraft, rocket and satellite structures. Both the correlation of acoustic pressure loads and the panel deflections, were measured in an 8-m diameter transonic wind tunnel. Using the measured correlation of acoustic pressures, as an input to a finite-element aeroelastic code, the panel response was reproduced. The latter was also satisfactorily reproduced, using again the aeroelastic code, with input given by a theoretical formula for the correlation of acoustic pressures; the derivation of this formula, and the semi-empirical parameters which appear in it, are included in this paper. The comparison of acoustic responses in aeroacoustic wind tunnels (AWT) and progressive wave tubes (PWT) shows that much work needs to be done to bridge that gap; this is important since the PWT is the standard test means, whereas the AWT is more representative of real flight conditions but also more demanding in resources. Since this may be the first instance of successful modelling of acoustic fatigue, it may be appropriate to list briefly the essential ``positive'' features and associated physical phenomena: (i) a standard aeroelastic structural code can predict acoustic fatigue, provided that the correlation of pressure loads be adequately specified; (ii) the correlation of pressure loads is determined by the interference of acoustic waves, which depends on the exact evaluation of multiple scattering integrals, involving the statistics of random phase shifts; (iii) for the relatively low frequencies (one to a few hundred Hz) of aeroacoustic fatigue, the main cause of random phase effects is scattering by irregular wakes, which are thin on wavelength scale, and appear as partially reflecting rough interfaces. It may also be appropriate to mention some of the ``negative'' features, to which may be attached illusory

  14. Predictions of a Supersonic Jet-in-Crossflow: Comparisons Among CFD Solvers and with Experiment

    DTIC Science & Technology

    2014-09-01

    data was oriented with the nozzle at y = 0. Hence, the comparisons with CFD results are presented with nozzle on the bottom wall and the jet plume ...The AMRDEC CFD model includes the full Navier-Stokes (FNS) equation set providing an aero-thermo- chemical plume / airframe predictions for unsteady...Predictions of a Supersonic Jet-in-Crossflow: Comparisons Among CFD Solvers and with Experiment by James DeSpirito, Kevin D Kennedy, Clark

  15. Comparison of calculated and experimental results of fragmenting cylinder experiments

    SciTech Connect

    WILSON,L.T.; REEDAL,D.R.; KIPP,MARLIN E.; MARTINEZ,REINA R.; GRADY,D.E.

    2000-06-02

    The Grady-Kipp fragmentation model provides a physically based method for determining the fracture and breakup of materials under high loading rates. Recently, this model has been implemented into the CTH Shock Physics Code and has been used to simulate several published experiments. Materials studied in this paper are AerMet 100 steel and a 90% tungsten alloy. The experimental geometry consists of a right circular cylinder filled with an explosive main charge that is initiated at its center. The sudden expansion of the resulting detonation products causes fracture of the cylinder. Strain rates seen in the cylinder are on the order of 10{sup 4} s{sup {minus}1}. The average fragment sizes calculated with the Grady-Kipp fragmentation model successfully replicate the mean fragment size obtained from the experimental fragment distribution. When Poisson statistics are applied to the calculated local average fragment sizes, good correlation is also observed with the shape of the experimental cumulative fragment distribution. The experimental fragmentation results, CTH numerical simulations, and correlation of these numerical results with the experimental data are described.

  16. Best-worst scaling vs. discrete choice experiments: an empirical comparison using social care data.

    PubMed

    Potoglou, Dimitris; Burge, Peter; Flynn, Terry; Netten, Ann; Malley, Juliette; Forder, Julien; Brazier, John E

    2011-05-01

    This paper presents empirical findings from the comparison between two principal preference elicitation techniques: discrete choice experiments and profile-based best-worst scaling. Best-worst scaling involves less cognitive burden for respondents and provides more information than traditional "pick-one" tasks asked in discrete choice experiments. However, there is lack of empirical evidence on how best-worst scaling compares to discrete choice experiments. This empirical comparison between discrete choice experiments and best-worst scaling was undertaken as part of the Outcomes of Social Care for Adults project, England, which aims to develop a weighted measure of social care outcomes. The findings show that preference weights from best-worst scaling and discrete choice experiments do reveal similar patterns in preferences and in the majority of cases preference weights--when normalised/rescaled--are not significantly different.

  17. Use of social comparisons in interviews about young adults' experiences of chronic illness.

    PubMed

    Heaton, Janet

    2015-03-01

    In this article I examine how young adults used social comparisons in research interviews about their experiences of chronic illness. The interviews were originally conducted not only to provide data for academic analysis but also to generate experiential accounts for publication online as part of an Internet-based health information resource for patients, professionals, and the public wanting to learn about people's real-life experiences of illness in the United Kingdom. Through secondary analysis of these data, I show how the young adults used various social comparisons to represent themselves and their experiences to the target audience. Two new concepts-analogues and foils-are introduced to describe how the young adults likened themselves to, and contrasted themselves with, different reference groups in their accounts. Through these and related strategies, they created positive renditions of their experiences for the audience, helping to inform and support others in the process.

  18. Use of Social Comparisons in Interviews About Young Adults’ Experiences of Chronic Illness

    PubMed Central

    2015-01-01

    In this article I examine how young adults used social comparisons in research interviews about their experiences of chronic illness. The interviews were originally conducted not only to provide data for academic analysis but also to generate experiential accounts for publication online as part of an Internet-based health information resource for patients, professionals, and the public wanting to learn about people’s real-life experiences of illness in the United Kingdom. Through secondary analysis of these data, I show how the young adults used various social comparisons to represent themselves and their experiences to the target audience. Two new concepts—analogues and foils—are introduced to describe how the young adults likened themselves to, and contrasted themselves with, different reference groups in their accounts. Through these and related strategies, they created positive renditions of their experiences for the audience, helping to inform and support others in the process. PMID:25281241

  19. Bayesian Approach to Assessing Uncertainty and Calculating a Reference Value in Key Comparison Experiments

    PubMed Central

    Toman, Blaza

    2005-01-01

    International experiments called Key Comparisons pose an interesting statistical problem, the estimation of a quantity called a Reference Value. There are many possible forms that this estimator can take. Recently, this topic has received much international attention. In this paper, it is argued that a fully Bayesian approach to this problem is compatible with the current practice of metrology, and can easily be used to create statistical models which satisfy the varied properties and assumptions of these experiments. PMID:27308182

  20. Comparison of Electron Cloud Simulation and Experiments in the High-Current Experiment

    SciTech Connect

    Cohen, R; Friedman, A; Covo, M K; Lund, S; Molvik, A; Bieniosek, F; Seidl, P; Vay, J; Verboncoeur, J; Stoltz, P; Veitzer, S

    2004-10-07

    A set of experiments has been performed on the High-Current Experiment (HCX) facility at LBNL, in which the ion beam is allowed to collide with an end plate and thereby induce a copious supply of desorbed electrons. Through the use of combinations of biased and grounded electrodes positioned in between and downstream of the quadrupole magnets, the flow of electrons upstream into the magnets can be turned on or off. Properties of the resultant ion beam are measured under each condition. The experiment is modeled via a full three-dimensional, two species (electron and ion) particle simulation, as well as via reduced simulations (ions with appropriately chosen model electron cloud distributions, and a high-resolution simulation of the region adjacent to the end plate). The three-dimensional simulations are the first of their kind and the first to make use of a timestep-acceleration scheme that allows the electrons to be advanced with a timestep that is not small compared to the highest electron cyclotron period. The simulations reproduce qualitative aspects of the experiments, illustrate some unanticipated physical effects, and serve as an important demonstration of a developing simulation capability.

  1. Comparison of electron cloud simulation and experiments in the high-current experiment

    SciTech Connect

    Cohen, R.H.; Friedman, A.; Covo, M. Kireeff; Lund, S.M.; Molvik, A.W.; Bieniosek, F.M.; Seidl, P.A.; Vay, J.-L.; Verboncoeur, J.; Stoltz, P.; Veitzer, S.

    2004-08-27

    A set of experiments has been performed on the High-Current Experiment (HCX) facility at LBNL, in which the ion beam is allowed to collide with an end plate and thereby induce a copious supply of desorbed electrons. Through the use of combinations of biased and grounded electrodes positioned in between and downstream of the quadrupole magnets, the flow of electrons upstream into the magnets can be turned on or off. Properties of the resultant ion beam are measured under each condition. The experiment is modeled via a full three-dimensional, two species (electron and ion) particle simulation, as well as via reduced simulations (ions with appropriately chosen model electron cloud distributions, and a high-resolution simulation of the region adjacent to the end plate). The three-dimensional simulations are the first of their kind and the first to make use of a timestep-acceleration scheme that allows the electrons to be advanced with a timestep that is not small compared to the highest electron cyclotron period. The simulations reproduce qualitative aspects of the experiments, illustrate some unanticipated physical effects, and serve as an important demonstration of a developing simulation capability.

  2. Calculation to experiment comparison of SPND signals in various nuclear reactor environments

    SciTech Connect

    Barbot, Loic; Radulovic, Vladimir; Fourmentel, Damien; Snoj, Luka; Tarchalski, Mikolaj; Dewynter-Marty, Veronique; Malouch, Fadhel

    2015-07-01

    In the perspective of irradiation experiments in the future Jules Horowitz Reactor (JHR), the Instrumentation Sensors and Dosimetry Laboratory of CEA Cadarache (France) is developing a numerical tool for SPND design, simulation and operation. In the frame of the SPND numerical tool qualification, dedicated experiments have been performed both in the Slovenian TRIGA Mark II reactor (JSI) and very recently in the French CEA Saclay OSIRIS reactor, as well as a test of two detectors in the core of the Polish MARIA reactor (NCBJ). A full description of experimental set-ups and neutron-gamma calculations schemes are provided in the first part of the paper. Calculation to experiment comparison of the various SPNDs in the different reactors is thoroughly described and discussed in the second part. Presented comparisons show promising final results. (authors)

  3. Supersonic pressure measurements and comparison of theory to experiment for an arrow-wing configuration

    NASA Technical Reports Server (NTRS)

    Manro, M. E.

    1976-01-01

    A wind tunnel test of an arrow-wing-body configuration consisting of flat and twisted wings, as well as leading- and trailing-edge control surface deflections, was conducted at Mach numbers from 1.54 to 2.50 to provide an experimental pressure data base for comparison with theoretical methods. Theory-to-experiment comparisons of detailed pressure distributions were made using a state-of-the-art inviscid flow, constant-pressure-panel method. Emphasis was on conditions under which this theory is valid for both flat and twisted wings.

  4. Comparisons of Transport and Dispersion Model Predictions of the Joint Urban 2003 Field Experiment

    DTIC Science & Technology

    2007-03-01

    Comparisons of Transport and Dispersion Model Predictions of the Joint Urban 2003 Field Experiment I N S T I T U T E F O R D E F E N S E A N A L Y...T E F O R D E F E N S E A N A L Y S E S IDA Paper P-4195 Comparisons of Transport and Dispersion Model Predictions of the Joint Urban 2003 Field...Material Transport and Dispersion Prediction Models .” The objective of this effort was to conduct analyses and special studies associated with the

  5. Transonic pressure measurements and comparison of theory to experiment for three arrow-wing configurations

    NASA Technical Reports Server (NTRS)

    Manro, M. E.

    1982-01-01

    Wind tunnel tests of arrow-wing body configurations consisting of flat, twisted, and cambered twisted wings, as well as a variety of leading and trailing edge control surface deflections, were conducted at Mach numbers from 0.4 to 1.05 to provide an experimental pressure data base for comparison with theoretical methods. Theory to experiment comparisons of detailed pressure distributions were made using state of the art attached flow methods. Conditions under which these theories are valid for these wings are presented.

  6. Microwave Transmission Through the Electron Cloud at the Fermilab Main Injector: Simulation and Comparison with Experiment

    SciTech Connect

    Lebrun, Paul L.G.; Veitzer, Seth Andrew; /Tech-X, Boulder

    2009-04-01

    Simulations of the microwave transmission properties through the electron cloud at the Fermilab Main Injector have been implemented using the plasma simulation code 'VORPAL'. Phase shifts and attenuation curves have been calculated for the lowest frequency TE mode, slightly above the cutoff frequency, in field free regions, in the dipoles and quadrupoles. Preliminary comparisons with experimental results for the dipole case are showed and will guide the next generation of experiments.

  7. Comparison of Computational Results with a Low-g, Nitrogen Slosh and Boiling Experiment

    NASA Technical Reports Server (NTRS)

    Stewart, Mark; Moder, Jeff

    2015-01-01

    The proposed paper will compare a fluid/thermal simulation, in FLUENT, with a low-g, nitrogen slosh experiment. The French Space Agency, CNES, performed cryogenic nitrogen experiments in several zero gravity aircraft campaigns. The computational results have been compared with high-speed photographic data, pressure data, and temperature data from sensors on the axis of the cylindrically shaped tank. The comparison between these experimental and computational results is generally favorable: the initial temperature stratification is in good agreement, and the two-phase fluid motion is qualitatively captured.

  8. Preliminary comparison of theory and experiment for a conical, pressurized-fluidized-bed coal combustor

    NASA Technical Reports Server (NTRS)

    Patch, R. W.

    1979-01-01

    A published model was used for a comparison of theory with an actual combustor burning caking bituminous coal and using limestone to reduce sulfur dioxide emission. Theoretical bed pressure drop was in good agreement with experiment. The burnable carbon elutriated was not in agreement with experiment, at least partly because the exhaust port was apparently below the transport disengaging height. The observed nitrogen oxides emission rate was about half the theoretical value. There was order-or-magnitude agreement of sulfur dioxide emission rates.

  9. INTERCAL: long-term inter-comparison experiment for dose rate and spectrometric probes.

    PubMed

    Bleher, M; Doll, H; Harms, W; Stöhlker, U

    2014-08-01

    The Schauinsland inter-calibration facility (INTERCAL) has been designed to enable long-term comparison experiments for 20 different dose rate probes from different networks. Two reference probes characterised by the European Radiation Dosimetry WG3 inter-calibration experiments in 2008 and 2009 have been installed at the INTERCAL facility. Additional instrumentation provides measured data of activity in air and nuclide-specific dose rate as well as environmental parameters such as air pressure, temperature, precipitation and soil moisture. Complementary to WG3 experiments, the INTERCAL platform is an ideal framework to investigate the long-term behaviour of dose rate probes and different spectrometry systems under environmental conditions. Two additional exposure experiments were performed in April 2009 and in May 2012.

  10. Comparisons of CTH simulations with measured wave profiles for simple flyer plate experiments

    SciTech Connect

    Thomas, S. A.; Veeser, L. R.; Turley, W. D.; Hixson, R. S.

    2016-06-13

    We conducted detailed 2-dimensional hydrodynamics calculations to assess the quality of simulations commonly used to design and analyze simple shock compression experiments. Such simple shock experiments also contain data where dynamic properties of materials are integrated together. We wished to assess how well the chosen computer hydrodynamic code could do at capturing both the simple parts of the experiments and the integral parts. We began with very simple shock experiments, in which we examined the effects of the equation of state and the compressional and tensile strength models. We increased complexity to include spallation in copper and iron and a solid-solid phase transformation in iron to assess the quality of the damage and phase transformation simulations. For experiments with a window, the response of both the sample and the window are integrated together, providing a good test of the material models. While CTH physics models are not perfect and do not reproduce all experimental details well, we find the models are useful; the simulations are adequate for understanding much of the dynamic process and for planning experiments. However, higher complexity in the simulations, such as adding in spall, led to greater differences between simulation and experiment. Lastly, this comparison of simulation to experiment may help guide future development of hydrodynamics codes so that they better capture the underlying physics.

  11. Comparisons of CTH simulations with measured wave profiles for simple flyer plate experiments

    DOE PAGES

    Thomas, S. A.; Veeser, L. R.; Turley, W. D.; ...

    2016-06-13

    We conducted detailed 2-dimensional hydrodynamics calculations to assess the quality of simulations commonly used to design and analyze simple shock compression experiments. Such simple shock experiments also contain data where dynamic properties of materials are integrated together. We wished to assess how well the chosen computer hydrodynamic code could do at capturing both the simple parts of the experiments and the integral parts. We began with very simple shock experiments, in which we examined the effects of the equation of state and the compressional and tensile strength models. We increased complexity to include spallation in copper and iron and amore » solid-solid phase transformation in iron to assess the quality of the damage and phase transformation simulations. For experiments with a window, the response of both the sample and the window are integrated together, providing a good test of the material models. While CTH physics models are not perfect and do not reproduce all experimental details well, we find the models are useful; the simulations are adequate for understanding much of the dynamic process and for planning experiments. However, higher complexity in the simulations, such as adding in spall, led to greater differences between simulation and experiment. Lastly, this comparison of simulation to experiment may help guide future development of hydrodynamics codes so that they better capture the underlying physics.« less

  12. Standardized collection of MNase-seq experiments enables unbiased dataset comparisons

    PubMed Central

    2012-01-01

    Background The organization of eukaryotic DNA into chromatin has a strong influence on the accessibility and regulation of genetic information. The locations and occupancies of a principle component of chromatin, nucleosomes, are typically assayed through use of enzymatic digestion with micrococcal nuclease (MNase). MNase is an endo-exo nuclease that preferentially digests naked DNA and the DNA in linkers between nucleosomes, thus enriching for nucleosome-associated DNA. To determine nucleosome organization genome-wide, DNA remaining from MNase digestion is sequenced using high-throughput sequencing technologies (MNase-seq). Unfortunately, the results of MNase-seq can vary dramatically due to technical differences and this confounds comparisons between MNase-seq experiments, such as examining condition-dependent chromatin organizations. Results In this study we use MNase digestion simulations to demonstrate how MNase-seq signals can vary for different nucleosome configuration when experiments are performed with different extents of MNase digestion. Signal variation in these simulations reveals an important DNA sampling bias that results from a neighborhood effect of MNase digestion techniques. The presence of this neighborhood effect ultimately confounds comparisons between different MNase-seq experiments. To address this issue we present a standardized chromatin preparation which controls for technical variance between MNase-based chromatin preparations and enables the collection of similarly sampled (matched) chromatin populations. Standardized preparation of chromatin includes a normalization step for DNA input into MNase digestions and close matching of the extent of digestion between each chromatin preparation using gel densitometry analysis. The protocol also includes directions for successful pairing with multiplex sequencing reactions. Conclusions We validated our method by comparing the experiment-to-experiment variation between biological replicates of

  13. Comparison between theory and experiment for universal thermodynamics of a homogeneous, strongly correlated Fermi gas

    SciTech Connect

    Hu Hui; Liu Xiaji; Drummond, Peter D.

    2011-06-15

    We compare the theoretical predictions for universal thermodynamics of a homogeneous, strongly correlated Fermi gas with the latest experimental measurements reported by the ENS group [S. Nascimbene et al., Nature (London) 463, 1057 (2010)] and the Tokyo group [M. Horikoshi et al., Science 327, 442 (2010)]. The theoretical results are obtained using two diagrammatic theories, together with a virial expansion theory combined with a Pade approximation. We find good agreement between theory and experiment. In particular, the virial expansion, using a Pade approximation up to third order, describes the experimental results extremely well down to the superfluid transition temperature, T{sub c{approx}}0.16T{sub F}, where T{sub F} is the Fermi temperature. The comparison in this work complements our previous comparative study on the universal thermodynamics of a strongly correlated but trapped Fermi gas. The comparison also raises interesting issues about the unitary entropy and the applicability of the Pade approximation.

  14. L-Band Microwave Experiment On Russian Investigational Satellite, First Results And Comparison With SMOS Data

    NASA Astrophysics Data System (ADS)

    Smirnov, M.; Khaldin, A.

    2013-12-01

    The main scientific objective of mission with Zond-PP on Russian investigational satellite MKA-FKI No1 is development of techniques for retrieval: sea salinity in open oceans, soil moisture in global scales, vegetation state characteristics, sea ice characteristics. At the beginning stage of space experiments the main goals were to develop and test new space microwave radiometric instrument in order to solve technical objectives: investigation of RFI in L-band all over the globe, development and testing in-flight calibration techniques and others. First obtained results of our observations are presented. Zond-PP results were compared with MIRAS. For comparison were used results of brightness temperatures measurements obtained from Zond-PP and MIRAS in the same regions with minimal time difference. Results of comparison show general accordance in the brightness temperatures levels.

  15. Chinese students' science-related experiences: Comparison of the ROSE study in Xinjiang and Shanghai

    NASA Astrophysics Data System (ADS)

    Yeung, Yau-yuen; Li, Yufeng

    2015-05-01

    Background: Students' daily-life experiences may render favorable effects on the students' affective domain like interest, enthusiasm, motivation, joy, curiosity, awareness, and eagerness to learn science as not commonly found in the classroom environment. However, no rigorous research has been reported on those aspects in Mainland China despite many recent studies done in various Western countries. Purpose: This paper aims to report and compare the science-related experiences of ninth-graders from two places (in Urumqi City of Xinjiang province and Shanghai) in China through a large-scale survey of their junior secondary three students. Sample: The sample consists of 4115 students in Urumqi City (from 28 schools) and Shanghai (from 25 schools). Design and methods: This study adopted a Likert scale questionnaire instrument, as translated from the international Relevance Of Science Education (ROSE) Project. From a confirmatory factor analysis of the data, we identify and focus on six factors which are directly correlated with students' science-related experiences outside school environment in Xinjiang and Shanghai and employ relevant factor scores to compare the gender, regional, and socioeconomic effects. Results: As revealed by the t-test, gender and regional differences were statistically significant in affecting (1) students' outdoor living experience, (2) hands-on experience of transportation, and (3) their daily-life experience with do-it-yourself tools and models. In all three aspects, boys and Xinjiang students possessed richer experiences than girls and Shanghai students, respectively. Conclusions: Based on ANOVA tests, Shanghai students' out-of-school science-related experiences were more often significantly affected by various socioeconomic variables (including their parents' education and occupation and their family income) than Xinjiang students. From cross-regional comparison, Chinese students had much fewer science-related experiences than those of

  16. Comparison between Adaptive and Uniform Discontinuous Galerkin Simulations in Dry 2D Bubble Experiments

    DTIC Science & Technology

    2012-11-08

    Comparison between adaptive and uniform discontinuous Galerkin simulations in dry 2D bubble experiments Andreas Müllera,∗, Jörn Behrensb, Francis X...joern.behrens@zmaw.de (Jörn Behrens), fxgirald@nps.edu ( Francis X. Giraldo), vwirth@uni-mainz.de (Volkmar Wirth) Accepted by Journal of Computational...Mon. Weather Rev. 120 (1992) 1675–1706. [3] D. P. Bacon , N. N. Ahmad, Z. Boybeyi, T. J. Dunn, M. S. Hall, P. C. S. Lee, R. A. Sarma, M. D. Turner, K. T

  17. Comparison of Fire Model Predictions with Experiments Conducted in a Hangar With a 15 Meter Ceiling

    NASA Technical Reports Server (NTRS)

    Davis, W. D.; Notarianni, K. A.; McGrattan, K. B.

    1996-01-01

    The purpose of this study is to examine the predictive capabilities of fire models using the results of a series of fire experiments conducted in an aircraft hangar with a ceiling height of about 15 m. This study is designed to investigate model applicability at a ceiling height where only a limited amount of experimental data is available. This analysis deals primarily with temperature comparisons as a function of distance from the fire center and depth beneath the ceiling. Only limited velocity measurements in the ceiling jet were available but these are also compared with those models with a velocity predictive capability.

  18. Effects of numerical methods on comparisons between experiments and simulations of shock-accelerated mixing.

    SciTech Connect

    Rider, William; Kamm, J. R.; Tomkins, C. D.; Zoldi, C. A.; Prestridge, K. P.; Marr-Lyon, M.; Rightley, P. M.; Benjamin, R. F.

    2002-01-01

    We consider the detailed structures of mixing flows for Richtmyer-Meshkov experiments of Prestridge et al. [PRE 00] and Tomkins et al. [TOM 01] and examine the most recent measurements from the experimental apparatus. Numerical simulations of these experiments are performed with three different versions of high resolution finite volume Godunov methods. We compare experimental data with simulations for configurations of one and two diffuse cylinders of SF{sub 6} in air using integral measures as well as fractal analysis and continuous wavelet transforms. The details of the initial conditions have a significant effect on the computed results, especially in the case of the double cylinder. Additionally, these comparisons reveal sensitive dependence of the computed solution on the numerical method.

  19. Comparison of Stratospheric Aerosol and Gas Experiment II and balloon-borne stratospheric water vapor measurements

    NASA Technical Reports Server (NTRS)

    Pruvost, P.; Ovarlez, J.; Lenoble, J.; Chu, W. P.

    1993-01-01

    The Stratospheric Aerosol and Gas Experiment II has one channel at 940 nm related to water vapor. Two inversion procedures were developed independently in order to obtain the water vapor profile: the Chahine method by the Langley Research Center, and the Mill method by the Laboratoire d'Optique Atmospherique. Comparisons were made between these two algorithms and some results are presented at midlatitudes (about 45 deg N) and tropical latitudes (12-25 deg S). They are compared with in situ frost point hygrometer data provided by balloon experiments from the Laboratoire de Meteorologie Dynamique. At +/- 0.5 ppmv, agreement between the inversion results and the experimental results was obtained in the altitude range from 18-19 to 26-27 km. Below 18-19 km and above 26-27 km the error is larger (sometimes 1 ppmv and more).

  20. Quantitative comparison of experiment and theory for intense ultrashort laser-induced dissociation of H2^+

    NASA Astrophysics Data System (ADS)

    Sayler, A. M.; Anis, F.; McKenna, J.; Gaire, B.; Johnson, Nora G.; Carnes, K. D.; Esry, B. D.; Ben-Itzhak, I.

    2008-05-01

    Experimental measurements and theoretical calculations for intense ultrashort pulse laser-induced dissociation of H2^+ were performed under near identical conditions producing results for quantitative comparison. The 3D momentum distribution was measured for the fragments of an H2^+ beam after interaction with 10 fs, 790 nm pulses at intensities of 10^14, 10^13, and 10^12 W/cm^2. In parallel, the time-dependent Schr"odinger equation was solved in the Born-Oppenheimer representation including nuclear, rotational, and electronic excitation. To obtain angularly-resolved kinetic energy release distributions necessary to compare to measurements, the final wavefunctions, projected onto the scattering states, are averaged over the vibrational state, intensity volume, and thermal distribution appropriate to the experiment. The results of these measurements and calculations are contrasted, testing the quantitative agreement of theory and experiment for ultrashort pulses at these intensities.

  1. Visualizing the Impact of Art: An Update and Comparison of Current Psychological Models of Art Experience.

    PubMed

    Pelowski, Matthew; Markey, Patrick S; Lauring, Jon O; Leder, Helmut

    2016-01-01

    The last decade has witnessed a renaissance of empirical and psychological approaches to art study, especially regarding cognitive models of art processing experience. This new emphasis on modeling has often become the basis for our theoretical understanding of human interaction with art. Models also often define areas of focus and hypotheses for new empirical research, and are increasingly important for connecting psychological theory to discussions of the brain. However, models are often made by different researchers, with quite different emphases or visual styles. Inputs and psychological outcomes may be differently considered, or can be under-reported with regards to key functional components. Thus, we may lose the major theoretical improvements and ability for comparison that can be had with models. To begin addressing this, this paper presents a theoretical assessment, comparison, and new articulation of a selection of key contemporary cognitive or information-processing-based approaches detailing the mechanisms underlying the viewing of art. We review six major models in contemporary psychological aesthetics. We in turn present redesigns of these models using a unified visual form, in some cases making additions or creating new models where none had previously existed. We also frame these approaches in respect to their targeted outputs (e.g., emotion, appraisal, physiological reaction) and their strengths within a more general framework of early, intermediate, and later processing stages. This is used as a basis for general comparison and discussion of implications and future directions for modeling, and for theoretically understanding our engagement with visual art.

  2. Visualizing the Impact of Art: An Update and Comparison of Current Psychological Models of Art Experience

    PubMed Central

    Pelowski, Matthew; Markey, Patrick S.; Lauring, Jon O.; Leder, Helmut

    2016-01-01

    The last decade has witnessed a renaissance of empirical and psychological approaches to art study, especially regarding cognitive models of art processing experience. This new emphasis on modeling has often become the basis for our theoretical understanding of human interaction with art. Models also often define areas of focus and hypotheses for new empirical research, and are increasingly important for connecting psychological theory to discussions of the brain. However, models are often made by different researchers, with quite different emphases or visual styles. Inputs and psychological outcomes may be differently considered, or can be under-reported with regards to key functional components. Thus, we may lose the major theoretical improvements and ability for comparison that can be had with models. To begin addressing this, this paper presents a theoretical assessment, comparison, and new articulation of a selection of key contemporary cognitive or information-processing-based approaches detailing the mechanisms underlying the viewing of art. We review six major models in contemporary psychological aesthetics. We in turn present redesigns of these models using a unified visual form, in some cases making additions or creating new models where none had previously existed. We also frame these approaches in respect to their targeted outputs (e.g., emotion, appraisal, physiological reaction) and their strengths within a more general framework of early, intermediate, and later processing stages. This is used as a basis for general comparison and discussion of implications and future directions for modeling, and for theoretically understanding our engagement with visual art. PMID:27199697

  3. RELAP5 assessment: LOFT large break L2-5

    SciTech Connect

    Thompson, S L; Kmetyk, L N

    1984-02-01

    RELAP5 is part of an effort to determine the ability of various systems codes to predict the detailed thermal/hydraulic response of LWRs during accident and off-normal conditions. The RELAP5 code is being assessed at SNLA against test data from various integral and separate effects test facilities. As part of this assessment matrix, a large break transient performed at the LOFT facility has been analyzed. The results show that RELAP5/MOD1 correctly calculates many of the major system variables (i.e., pressure, break flows, peak clad temperature) early in a large break LOCA. The major problems encountered in the analyses were incorrect pump coastdown and loop seal clearing early in the calculation, excessive pump speedup later in the transient (probably due to too much condensation-induced pressure drop at the ECC injection point), and excess ECC bypass calculated throughout the later portions of the test; only the latter problem significantly affected the overall results. This excess ECC bypass through the downcomer and vessel-side break resulted in too-large late-time break flows and high system pressure due to prolonged choked flow conditions. It also resulted in a second core heatup being calculated after the accumulator emptied, since water was not being retained in the vessel. Analogous calculations with a split-downcomer nodalization delivered some ECC water to the lower plenum, which was then swept up the core and upper plenum and out the other (pump-side) break; thus no significant differences in long-term overall behavior were evident between the calculations.

  4. Catchment Prediction In Changing Environments (CAPICHE): A Model Inter-Comparison Experiment

    NASA Astrophysics Data System (ADS)

    Hutton, Christopher; Nijzink, Remko; Pechlivanidis, Ilias; Capell, René; Wagener, Thorsten; Freer, Jim; Han, Dawei; Hrachowitz, Markus; Arheimer, Berit

    2016-04-01

    forcing, hydrological response and model parameter metrics (e.g. posterior distribution, parameter interactions). As part of the EUFP7 funded project Switch-On, the method is first applied in a collaborative model inter-comparison using open data from paired headwater catchments to analyse how different models simulate the effect of deforestation and subsequent re-growth on hydrological response. The simulation of paired catchments allows us to differentiate the effect of climate forcing and land-cover change on model parameters. In order to make the experiment open, the analysis code will be made available for re-use and therefore subsequent model inter-comparison.

  5. Gadolinium dosimetry, a problematic issue in the neutron capture therapy. Comparison between experiments and computational simulations.

    NASA Astrophysics Data System (ADS)

    Bufalino, D.; Cerullo, N.; Colli, V.; Gambarini, G.; Rosi, G.

    2006-05-01

    In GdNCT the interested isotope is 157Gd that captures neutrons with (n, ) reaction and also emits internal conversion and Auger electrons. These electrons have an important effect on DNA strands, mainly due to the property of gadolinium to link to DNA. The emitted gamma rays partially interacts with tumours but mainly diffuse in the body damaging healthy tissues. Therefore in the study of Gd therapeutical effect both dosimetric and microdosimetric analyses must be performed. At Pisa University, in the last years some works were performed by NCT group. At the present these researches are continued on these topics carrying out also a PhD thesis. In this frame some simulations, using MC code, were performed in order to evaluate the dose distribution due to Gd reactions. It is however necessary to calibrate the calculations on experimental results, though they are scarce in GdNCT. Some experiments with 157Gd were performed by Milan group using gel dosimetry [1, 2, 3]. Therefore some computational comparisons were done. In these article the results of this comparisons are shown and discussed.

  6. Comparison of Pressure Drop between Calculation and Experiment for a Two-phase Carbon Dioxide Loop

    NASA Astrophysics Data System (ADS)

    Mo, D.-C.; Xiao, W.-J.; Huang, Z.-C.; Sun, X.-H.; Chen, Y.; Lu, S.-S.; Li, T.-X.; Qi, X.-M.; Wang, Z.-X.; Pauw, A.; Bsibsi, M.; Gargiulo, C.; van Es, J.; He, Z.-H.

    2008-09-01

    Tracker thermal control system (TTCS) is an active-pumped two-phase carbon dioxide cooling loop, which is developed for the Alpha Magnetic Spectrometer tracker front-end electronics. The maintenance-free centrifugal pump is a critical component in the design mainly due to the limited pressure head with small mass flows. Therefore a correct pressure drop is required to predict the pressure drop for dynamic modeling. As the normal operational temperature of the carbon dioxide in the TTCS is from - 15°C to +15°C, which is very close to its critical point, 33°C, and many two-phase pressure drop correlations may not fit well here. In this paper, we attempt to correlate the pressure drops between the calculations and the experiment of the two-phase CO2 loop. The comparison will focus on one evaporator. Here, the Lockhart/Martinelli correlation is recorrelated with different definition C value for CO2 according to the test results. Comparison shows that, the new correlation can fit the test results well.

  7. Solar/Stellar Irradiance Comparison Experiment (SOLSTICE) on the Upper Atmosphere Research Satellite (UARS)

    NASA Technical Reports Server (NTRS)

    Rottman, Gary J.; Woods, Thomas N.; London, Julius; Ayres, Thomas R.

    2003-01-01

    A final report on the operational activities related to the UARS Solar Stellar irradiance Comparison Experiment (SOLSTICE) is presented. Scientific activities of SOLSTICE has also been supported. The UARS SOLSTICE originated at the University of Colorado in 1981. One year after the UARS launch in 1991, the operations and research support activities for SOLSTICE were moved to the High Altitude Observatory (HAO) of the National Center for Atmospheric Research (NCAR). The SOLSTICE program continued at HAO with the National Science Foundation, and after four years, it was moved once again back to the University of Colorado. At the University after 1997 this subject grant was issued to further extend the operations activities from July 2001 through September 2002. Although this is a final report for one particular activity, in fact the SOLSTICE operations activity -first at the University, then at HAO, and now again at the University -has continued in a seamless fashion.

  8. A study of dc discharge in cylindrical magnetron - comparison of experiment and PIC model

    NASA Astrophysics Data System (ADS)

    Behnke, J. F.; Csambal, C.; Tichy, M.; Kudrna, P.; Rusz, J.

    2000-10-01

    We present experimental and numerical study of the DC discharge in cylindrical magnetron in argon. The grounded discharge chamber-anode has 110 mm in length and 60 mm inner diameter. The co-axially placed cathode has 10 mm in diameter. The magnetic field is created by couple of coils. Experimental results have been obtained by radially movable planar Langmuir probe with its plane perpendicular to the magnetic field lines. The radial profiles of the floating and plasma potential, plasma density, and the electron energy distribution function have been measured. Numerical results were obtained using the modified 1D PIC code (Berkeley). The comparison between experiment and model results computed at similar conditions shows reasonable agreement in plasma density and electron mean energy. The computed electric field is usually higher than the experimental one. This difference we explain by the end effects that are not taken into account in 1D model.

  9. Image Correlation Applied to Single Crystal Plasticity Experiments and Comparison to Strain Gage Data

    SciTech Connect

    LeBlanc, M M; Florando, J N; Lassila, D H; Schmidt, T; Tyson II, J

    2005-06-29

    Full-field optical techniques are becoming increasingly popular for measuring the deformation of materials, especially in materials that exhibit non-uniform behavior. While there are many full-field techniques available (e.g. moire interferometry, electronic speckle pattern interferometry (ESPI), holography, and image correlation [1]), for our study of the deformation of single crystals, the image correlation technique was chosen for its insensitivity to vibrations and ability to measure large strains. While the theory and development of the algorithms for image correlation have been presented elsewhere [2,3] a comparative study to a conventional strain measurement device, such as a strain gage rosette, is desired to test the robustness and accuracy of the technique. The 6 Degrees of Freedom (6DOF) experiment, which was specifically designed to validate dislocation dynamics (DD) simulations [4], is ideally suited to compare the two methods. This experiment is different from previous experiments on single crystals in that it allows the crystal to deform essentially unconstrained, in both the elastic and plastic regimes, by allowing the bottom of the sample to move as the sample is being compressed. This unconstrained motion prevents the internal crystal planes from rotating during the deformation as typically seen in the pioneering work of Schmid [5] and Taylor [6]. In the early development of the 6DOF apparatus, stacked strain gage rosettes were used to provide the strain data [7]. While very accurate at small strains, strain gages provide an averaged measurement over a small area and cannot be used to measure the inhomogeneous plastic strains that typically occur during the 6DOF experiment. An image correlation technique can measure the full-field in-plane and out-of-plane deformation that occurs in single crystals, and a comparison to the strain gage data at small strains can test the accuracy of the method.

  10. Inductively-coupled plasmas in pure chlorine: comparison experiments/HPEM

    NASA Astrophysics Data System (ADS)

    Booth, Jean-Paul; Sirse, Nishant; Azamoum, Yasmina; Chabert, Pascal

    2012-10-01

    Inductively-coupled plasmas in chlorine-based gas mixtures are widely used for etching of nanometric features in silicon for CMOS device manufacture. This system is also of considerable fundamental interest as an archetype of strongly electronegative plasmas in a simple gas, for which reliable techniques exist to measure the densities of all key species. As such, it is an ideal test-bed for comparison of simulations to experiment. We have developed a technique based on two-photon Laser-Induced Fluorescence to determine the absolute Cl atom density. The Cl surface recombination coefficient was determined from time-resolved measurements in the afterglow. Electron densities were determined by microwave hairpin resonator and EEDF's were measured by Langmuir probe. Whereas the HPEM results were in good agreement at lower pressures (below 10mTorr), electron densities are increasingly underestimated at higher pressures. The gas temperature was measured by Doppler-resolved Infra-red Laser Absorption spectroscopy of Ar metastable atoms (with a small fraction Ar added). At higher pressures the gas temperature was considerably underestimated by the model. The concomitant overestimation of the gas density is a major reason for the disagreement between model and experiment.

  11. Comparison of chemical and nuclear explosions: Numerical simulations of the Non-Proliferation Experiment

    SciTech Connect

    Kamm, J.R.; Bos, R.J.

    1995-06-01

    In this paper the authors discuss numerical simulations of the Non-Proliferation Experiment (NPE), which was an underground explosion conducted in September 1993 in the volcanic tuff of the Nevada Test Site. The NPE source consisted of 1.29 {times} 10{sup 6} kg of ANFO-emulsion blasting agent, with the approximate energy of 1.1 kt, emplaced 389 m beneath the surface of Rainier Mesa. The authors compare detailed numerical simulations of the NPE with data collected from that experiment, and with calculations of an equally energetic nuclear explosion in identical geology. Calculated waveforms, at ranges out to approximately 1 km, agree moderately well in the time domain with free-field data, and are in qualitative agreement with free-surface records. Comparison of computed waveforms for equally energetic chemical and nuclear sources reveals relatively minor differences beyond the immediate near-source region, with the chemical source having an {approximately}25% greater seismic moment but otherwise indistinguishable (close-in) seismic source properties. 41 refs., 67 figs., 7 tabs.

  12. Comparison of Spacecraft Contamination Models with Well-Defined Flight Experiment

    NASA Technical Reports Server (NTRS)

    Pippin, G. H.

    1998-01-01

    The report presents analyzed surface areas on particular experiment trays from the Long Duration Exposure Facility (LDEF) for silicone-based molecular contamination. The trays for examination were part of the Ultra-Heavy Cosmic Ray Experiment (UHCRE). These particular trays were chosen because each tray was identical to the others in construction, and the materials on each tray were well known, documented, and characterized. In particular, a known specific source of silicone contamination was present on each tray. Only the exposure conditions varied from tray to tray. The results of post-flight analyses of surfaces of three trays were compared with the predictions of the three different spacecraft molecular contamination models. Phase one tasks included: 1) documenting the detailed geometry of the hardware; 2) determining essential properties of the anodized aluminum, Velcro(Tm), silverized Teflon(Tm), silicone gaskets, and DC6-1104(Tm) silicone adhesive materials used to make the trays, tray covers, and thermal control blankets; 3) selecting and removing areas from each tray; and 4) beginning surface analysis of the selected tray walls. Phase two tasks included: 1) completion of surface analysis measurements of the selected tray surface, 2) obtaining auger depth profiles at selected locations, and 3) running versions of the ISEM, MOFLUX, and PLIMP (Plume Impingement) contamination prediction models and making comparisons with experimental results.

  13. Comparison of one- and three-dimensional soil vapour extraction experiments.

    PubMed

    Duggal, A; Zytner, R G

    2009-04-01

    Soil vapour extraction (SVE) is a common remediation technology used to clean soil contaminated with gasoline. Even though many studies have been completed on SVE, the majority of them have been at the one-dimensional level, while SVE occurs at a three dimensional level. Accordingly, one-dimensional and radial column laboratory experiments were completed to determine if the experimental configuration made a difference with the results. Two soil types were tested at a variety of flow rates. The contaminant used was toluene. The results were analysed both qualitatively and quantitatively. Analysis of both systems showed them to provide good mass closures. On a qualitative basis, the one-dimensional experiments showed that an increase in flow rates did not result in significant mass transfer limitations for the air flow rates tested. The radial columns revealed mass transfer limitations that were not seen in the one-dimensional column. Quantitative comparison through back-calculated mass transfer coefficients confirmed the trends seen in the qualitative analysis. It is unclear if this is a result of geometry of the radial column or the higher velocities within the radial column. The results indicate that further work with the radial column is necessary to better understand field SVE systems, making it possible to better predict field performance.

  14. Comparison of Measured and Simulated Albedo Signals in the ATIC Experiment

    NASA Technical Reports Server (NTRS)

    Zatsepin, V. I.; Adams, J. H.; Ahn, H. S.; Bashindzhagyan, G. L.; Batkov, K. E.; Chang, J.; Christl, M.; Fazely, A. R.; Ganel, O.; Gunasingha, R. M.

    2003-01-01

    Albedo, radiation backscattered from an interaction and from the subsequent shower development, provides a 'background' for calorimeter experiments. In ATIC (Advanced Thin Ionization Calorimeter), a balloon borne instrument to measure cosmic ray composition and energy spectra for elements from hydrogen to iron from 30 GeV to near 100 TeV, a fully active BGO calorimeter follows a carbon interaction target and scintillator holdoscopes. The first detector is a silicon matrix constructed of 4480 individual silicon pixels, each 2 cm x 1.5 cm, that provide a measurement of the charge of the primary particle in the presence of albedo. ATIC had two successful balloon flights in Antarctica: from 28 Dec 2000 to 13 Jan 2001 (ATIC-1) and from 29 Dec 2002 to 18 Jan 2003 (ATIC-2). A comparison of albedo signals in the silicon matri:x in ATIC-1 experiment with simulations performed using the GEANT 3.21 code and the QGSM event generator for nucleus-nucleus interactions is presented.

  15. Our Experience with Brow Ptosis Correction: A Comparison of 4 Techniques

    PubMed Central

    Pascali, Michele; Avantaggiato, Anna; Cervelli, Valerio

    2015-01-01

    Background: Brow elevation is one of the goals of surgical rejuvenation procedures. In this article, the authors reviewed their experience with brow lift, and they compared 4 different techniques: direct brow lift, brow lift with endotine ribbon device, brow lift with temporoparietalis imbrication, and brow lift with Mersilene mesh to provide long-lasting results. Methods: This is a retrospective study of 80 patients (20 for each group), aged between 48 and 75 years undergoing brow lift surgery, between January 2011 and January 2013. In all cases, the brow lift was associated with an upper blepharoplasty. The amount of brow elevation reduced was assessed by comparison of the preoperative and postoperative vertical distances between the superior eyebrow hairline and the midpupil and lateral and medial canthal angle. The average follow-up period was 18 months. Results: No incidences of infection, alopecia, or excessive scarring were noticed. The main complication associated with direct brow lift was visibility of the scar in 2 patients. One patient treated with brow lift with suture had recurrent eyebrow ptosis. Transient frontal paresthesia was noticed in 1 case treated with endotine ribbon device and in 1 case treated with Mersilene mesh, but this sensation returned by 6–12 weeks. Conclusions: In our experience, there does not exist a technique better than the other, but the best procedure depends on eyebrow contour, sex and age of the patient, magnitude of desired correction, presence or absence of patient’s hair, and patient’s expectations. PMID:25878922

  16. Convection in a Very Compressible Fluid: Comparison of Simulations With Experiments

    NASA Technical Reports Server (NTRS)

    Meyer, H.; Furukawa, A.; Onuki, A.; Kogan, A. B.

    2003-01-01

    The time profile (Delta)T(t) of the temperature difference, measured across a very compressible fluid layer of supercritical He-3 after the start of a heat flow, shows a damped oscillatory behavior before steady state convection is reached. The results for (Delta)T(t) obtained from numerical simulations and from laboratory experiments are compared over a temperature range where the compressibility varies by a factor of approx. = 40. First the steady-state convective heat current j(sup conv) as a function of the Rayleigh number R(alpha) is presented, and the agreement is found to be good. Second, the shape of the time profile and two characteristic times in the transient part of (Delta)T(t) from simulations and experiments are compared, namely: 1) t(sub osc), the oscillatory period and 2) t(sub p), the time of the first peak after starting the heat flow. These times, scaled by the diffusive time tau(sub D) versus R(alpha), are presented. The agreement is good for t(sup osc)/tau(sub D), where the results collapse on a single curve showing a powerlaw behavior. The simulation hence confirms the universal scaling behavior found experimentally. However for t(sub p)/tau(sub D), where the experimental data also collapse on a single curve, the simulation results show systematic departures from such a behavior. A possible reason for some of the disagreements, both in the time profile and in t(sub p) is discussed. In the Appendix a third characteristic time, t(sub m), between the first peak and the first oscillation minimum is plotted and a comparison between the results of experiments and simulations is made.

  17. Case-Mix Adjustment and the Comparison of Community Health Center Performance on Patient Experience Measures

    PubMed Central

    Johnson, M Laura; Rodriguez, Hector P; Solorio, M Rosa

    2010-01-01

    Objective To assess the effect of case-mix adjustment on community health center (CHC) performance on patient experience measures. Data Sources A Medicaid-managed care plan in Washington State collected patient survey data from 33 CHCs over three fiscal quarters during 2007–2008. The survey included three composite patient experience measures (6-month reports) and two overall ratings of care. The analytic sample includes 2,247 adult patients and 2,859 adults reporting for child patients. Study Design We compared the relative importance of patient case-mix adjusters by calculating each adjuster's predictive power and variability across CHCs. We then evaluated the impact of case-mix adjustment on the relative ranking of CHCs. Principal Findings Important case-mix adjusters included adult self-reported health status or parent-reported child health status, adult age, and educational attainment. The effects of case-mix adjustment on patient reports and ratings were different in the adult and child samples. Adjusting for race/ethnicity and language had a greater impact on parent reports than adult reports, but it impacted ratings similarly across the samples. The impact of adjustment on composites and ratings was modest, but it affected the relative ranking of CHCs. Conclusions To ensure equitable comparison of CHC performance on patient experience measures, reports and ratings should be adjusted for adult self-reported health status or parent-reported child health status, adult age, education, race/ethnicity, and survey language. Because of the differential impact of case-mix adjusters for child and adult surveys, initiatives should consider measuring and reporting adult and child scores separately. PMID:20337738

  18. Social comparison processes, narrative mapping and their shaping of the cancer experience: a case study of an elite athlete.

    PubMed

    Sparkes, Andrew C; Pérez-Samaniego, Víctor; Smith, Brett

    2012-09-01

    Drawing on data generated by life history interviews and fieldwork observations we illuminate the ways in which a young elite athlete named David (a pseudonym) gave meaning to his experiences of cancer that eventually led to his death. Central to this process were the ways in which David utilized both social comparisons and a narrative map provided by the published autobiography of Lance Armstrong (2000). Our analysis reveals the selective manner in which social comparison processes operated around the following key dimensions: mental attitude to treatment; the sporting body; the ageing body; and physical appearance. The manner in which different comparison targets were chosen, the ways in which these were framed by Armstrong's autobiography, and the work that the restitution narrative as an actor did in this process are also examined. Some reflections are offered regarding the experiential consequences of the social comparison processes utilized by David when these are shaped by specific forms of embodiment and selective narrative maps of cancer survival.

  19. Faraday rotation enhancement of gold coated Fe2O3 nanoparticles: comparison of experiment and theory.

    PubMed

    Dani, Raj Kumar; Wang, Hongwang; Bossmann, Stefan H; Wysin, Gary; Chikan, Viktor

    2011-12-14

    Understanding plasmonic enhancement of nanoscale magnetic materials is important to evaluate their potential for application. In this study, the Faraday rotation (FR) enhancement of gold coated Fe(2)O(3) nanoparticles (NP) is investigated experimentally and theoretically. The experiment shows that the Faraday rotation of a Fe(2)O(3) NP solution changes from approximately 3 rad/Tm to 10 rad/Tm as 5 nm gold shell is coated on a 9.7 nm Fe(2)O(3) core at 632 nm. The results also show how the volume fraction normalized Faraday rotation varies with the gold shell thickness. From the comparison of experiment and calculated Faraday rotation based on the Maxwell-Garnett theory, it is concluded that the enhancement and shell dependence of Faraday rotation of Fe(2)O(3) NPs is a result of the shifting plasmon resonance of the composite NP. In addition, the clustering of the NPs induces a different phase lag on the Faraday signal, which suggests that the collective response of the magnetic NP aggregates needs to be considered even in solution. From the Faraday phase lag, the estimated time of the full alignment of the magnetic spins of bare (cluster size 160 nm) and gold coated NPs (cluster size 90 nm) are found to be 0.65 and 0.17 μs. The calculation includes a simple theoretical approach based on the Bruggeman theory to account for the aggregation and its effect on the Faraday rotation. The Bruggeman model provides a qualitatively better agreement with the experimentally observed Faraday rotation and points out the importance of making a connection between component properties and the average "effective" optical behavior of the Faraday medium containing magnetic nanoparticles.

  20. Contrail Cirrus Forecasts for the ML-CIRRUS Experiment and Some Comparison Results

    NASA Astrophysics Data System (ADS)

    Schumann, Ulrich; Graf, Kaspar; Bugliaro, Luca; Dörnbrack, Andreas; Giez, Andreas; Jurkat, Tina; Kaufmann, Stefan; Krämer, Martina; Minikin, Andreas; Schäfler, Andreas; Voigt, Christiane; Wirth, Martin; Zahn, Andreas; Ziereis, Helmut

    2015-04-01

    Model simulations with the contrail cirrus prediction model CoCiP driven by numerical weather prediction (NWP) data provided from the European Centre for Medium Range Forecasts (ECMWF) and global aircraft waypoint data show a mean computed cover (for optical depth larger than 0.1) of 0.23% globally, and 5.4% over mid Europe (Schumann and Graf, JGR, 2013). The computed mean longwave radiative forcing (RF) reaches 3 W m-2 over mid Europe (10°W-20°E and 40°N-55°N), and 0.13 W m-2 globally. The global net RF is about 40-60% smaller because of compensating shortwave cooling induced by contrails during daytime. The results depend on several model details such as the number of ice particles forming from aircraft soot emissions, the contrail plume dispersion, ice particle sedimentation etc., all influencing contrail life time and their optical properties. The quantitative results depend also strongly on ambient relative humidity, vertical motion and on ice water content of other cirrus predicted by the NWP model. In order to test and possibly improve this and other contrail models, high-quality observations are needed to which multi-parameter model output can be compared. The Mid-Latitude Cirrus Experiment ML-CIRRUS was performed (see C. Voigt et al., this conference) with a suite of in-situ and Lidar instruments for airborne measurements on the research aircraft HALO. Before and during the mission, CoCiP was run daily to provide 3-days forecasts of contrail cover using operational ECMWF forecasts and historical traffic data. CoCiP forecast output was made available in an internet tool twice a day for experiment planning. The one-day and two-day contrail forecasts often showed only small differences. Still, most recent forecasts and detailed satellite observations results were transmitted via satellite link to the crew for onboard campaign optimization. After the campaign, a data base of realistic air traffic data has been setup from various sources, and CoCiP was

  1. Post-Shot Simulations of NIC Experiments with Comparison to X-ray Measurements

    NASA Astrophysics Data System (ADS)

    Eder, David; Jones, Oggie; Suter, Larry; Moore, Alastair; Schneider, Marilyn

    2012-10-01

    National Ignition Campaign experiments at NIF are ongoing and post-shot simulations play an important role in understanding the physical processes occurring in the quest for demonstrating fusion burn. In particular, it is important to understand the x-ray environment inside the hohlraum targets, which is studied using various x-ray diagnostics. The Dante instrument measures the time dependent x-ray emission escaping out of the hohlraum laser entrance holes (LEHs) and the SXI instrument provides a time-integrated image of both soft and hard x-rays. We compare calculated total x-ray emission with Dante data as well as the relative high energy Mband emission that contributes to capsule preheat. We correct our calculated x-ray emission to account for differences between simulation and data on LEH closure using SXI data. We provide results for both ``standard candle'' simulation with no added multipliers and for simulations with time-dependent multipliers that are used to obtain agreement with shock timing and implosion velocity data. The physics justification for the use of multipliers is to account for potential missing energy or incorrect ablation modeling. The relative importance of these two effects can be studied through comparison of post-shot simulations with x-ray measurements.

  2. A Comparison of Internal Dispositions and Career Trajectories after Collaborative versus Apprenticed Research Experiences for Undergraduates

    PubMed Central

    Frantz, Kyle J.; Demetrikopoulos, Melissa K.; Britner, Shari L.; Carruth, Laura L.; Williams, Brian A.; Pecore, John L.; DeHaan, Robert L.; Goode, Christopher T.

    2017-01-01

    Undergraduate research experiences confer benefits on students bound for science, technology, engineering, and mathematics (STEM) careers, but the low number of research professionals available to serve as mentors often limits access to research. Within the context of our summer research program (BRAIN), we tested the hypothesis that a team-based collaborative learning model (CLM) produces student outcomes at least as positive as a traditional apprenticeship model (AM). Through stratified, random assignment to conditions, CLM students were designated to work together in a teaching laboratory to conduct research according to a defined curriculum led by several instructors, whereas AM students were paired with mentors in active research groups. We used pre-, mid-, and postprogram surveys to measure internal dispositions reported to predict progress toward STEM careers, such as scientific research self-efficacy, science identity, science anxiety, and commitment to a science career. We are also tracking long-term retention in science-related career paths. For both short- and longer-term outcomes, the two program formats produced similar benefits, supporting our hypothesis that the CLM provides positive outcomes while conserving resources, such as faculty mentors. We discuss this method in comparison with course-based undergraduate research and recommend its expansion to institutional settings in which mentor resources are scarce. PMID:28130268

  3. A Comparison of Internal Dispositions and Career Trajectories after Collaborative versus Apprenticed Research Experiences for Undergraduates.

    PubMed

    Frantz, Kyle J; Demetrikopoulos, Melissa K; Britner, Shari L; Carruth, Laura L; Williams, Brian A; Pecore, John L; DeHaan, Robert L; Goode, Christopher T

    2017-01-01

    Undergraduate research experiences confer benefits on students bound for science, technology, engineering, and mathematics (STEM) careers, but the low number of research professionals available to serve as mentors often limits access to research. Within the context of our summer research program (BRAIN), we tested the hypothesis that a team-based collaborative learning model (CLM) produces student outcomes at least as positive as a traditional apprenticeship model (AM). Through stratified, random assignment to conditions, CLM students were designated to work together in a teaching laboratory to conduct research according to a defined curriculum led by several instructors, whereas AM students were paired with mentors in active research groups. We used pre-, mid-, and postprogram surveys to measure internal dispositions reported to predict progress toward STEM careers, such as scientific research self-efficacy, science identity, science anxiety, and commitment to a science career. We are also tracking long-term retention in science-related career paths. For both short- and longer-term outcomes, the two program formats produced similar benefits, supporting our hypothesis that the CLM provides positive outcomes while conserving resources, such as faculty mentors. We discuss this method in comparison with course-based undergraduate research and recommend its expansion to institutional settings in which mentor resources are scarce.

  4. Comparison of Staged Z-pinch Experiments at the NTF Zebra Facility with Mach2 simulations

    NASA Astrophysics Data System (ADS)

    Ruskov, E.; Wessel, F. J.; Rahman, H. U.; Ney, P.; Darling, T. W.; Johnson, Z.; McGee, E.; Covington, A.; Dutra, E.; Valenzuela, J. C.; Conti, F.; Narkis, J.; Beg, F.

    2016-10-01

    Staged Z-pinch experiments at the University of Nevada, Reno, 1MA Z-pinch Zebra facility were conducted. A hollow shell of argon gas liner is injected between 1 cm anode-cathode gap through a supersonic nozzle of 2.0 cm diameter with a throat gap of 240 microns. A deuterium plasma fill is injected inside the argon gas shell through a plasma gun as a fusible target plasma. An axial magnetic field is also applied throughout the pinch region. Experimental measurements such as pinch current, X-ray signal, neutron yield, and streak images are compared with MACH2 radiation hydrodynamic code simulations. The argon liner density profiles, obtained from the CFD (FLUENT), are used as an input to MACH2. The comparison suggests a fairly close agreement between the experimental measurements and the simulation results. This study not only helps to benchmark the code but also suggests the importance of the Z-pinch implosion time, optimizing both liner and target plasma density to obtain the maximum energy coupling between the circuit and the load. Advanced Research Projects Agency - Energy, DE-AR0000569.

  5. Determination of forces in a magnetic bearing actuator - Numerical computation with comparison to experiment

    NASA Technical Reports Server (NTRS)

    Knight, J. D.; Xia, Z.; Mccaul, E.; Hacker, H., Jr.

    1992-01-01

    Calculations of the forces exerted on a journal by a magnetic bearing actuator are presented, along with comparisons to experimentally measured forces. The calculations are based on two-dimensional solutions for the flux distribution in the metal parts and free space, using finite but constant permeability in the metals. Above a relative permeability of 10,000 the effects of changes in permeability are negligible, but below 10,000 decreases in permeability cause significant decreases in the force. The calculated forces are shown to depend on the metal permeability more strongly when the journal is displaced from its centered position. The predicted forces in the principal attractive direction are in good agreement with experiment when a relatively low value of permeability is chosen. The forces measured normal to the axis of symmetry when the journal is displaced from that axis, however, are significantly higher than predicted by theory, even with a value of relative permeability larger than 5000. These results indicate a need for further work including nonlinear permeability distributions.

  6. Stratospheric aerosol and gas experiments I and II comparisons with ozonesondes

    SciTech Connect

    Veiga, R.E.; Cunnold, D.M.; Chu, W.P.

    1995-05-20

    Ozone profiles measured by the Stratospheric Aerosol and Gas Experiments (SAGE) I and II are compared with ozonesonde profiles at 24 stations over the period extending from 1979 through 1991. Ozonesonde/satellite differences at 21 stations with SAGE II overpasses were computed down to 11.5 km in the midlatitudes, to 15.5 km in the lower latitudes, and for nine stations with SAGE I overpasses down to 15.5 km. The set of individual satellite and ozonesonde profile comparisons most closely colocated in time and space shows mean absolute differences relative to the satellite measurement of 6 {plus_minus} 2% for SAGE II and 8 {plus_minus}3% for SAGE I. The ensemble of ozonesonde/satellite differences, when averaged over all altitudes, shows that for SAGE II, 70% were less than 5%, whereas for SAGE I, 50% were less than 5%. The best agreement occurred in the altitude region near the ozone density maximum where almost all the relative differences were less than 5%. Most of the statistically significant differences occurred below the ozone maximum down to the tropopause in the region of steepest ozone gradients and typically ranged between 0 and {minus}20%. Correlations between ozone and aerosol extinction in the northern midlatitudes indicate that aerosols had no discernible impact on the ozonesonde/satellite differences and on the stratosphere during 1984 to mid-1991. 42 refs., 8 figs., 1 tab.

  7. Evolution of the bounded magnetized jet and comparison with Helimak experiments

    NASA Astrophysics Data System (ADS)

    Dahlburg, R. B.; Horton, W.; Rowan, W. L.; Correa, C.; Perez, J. C.

    2009-07-01

    Magnetized jets are important features of many systems of physical interest. To date, most interest has focused on solar and space physics and astrophysical applications, and hence the unbounded magnetized jet, and its cousin, the unbounded magnetized wake, have received the most attention. This work presents calculations of a bounded, magnetized jet for a laboratory experiments in the Helimak device [K. W. Gentle and H. He, Plasma Sci. Technol. 10, 284 (2008)]. The Helimak device has a toroidal magnetic field with a controlled velocity flow that represents jets in bounded systems. Experimental and theoretical features include three spatial dimensions, the inclusion of resistivity and viscosity, and the presence of no-slip walls. The results of the linearized model are computed with a Chebyshev-τ algorithm. The bounding walls stabilize the ideal varicose mode found in unbounded magnetized jets. The ideal sinuous mode persists in the bounded system. A comparison theorem is proved showing that two-dimensional modes are more unstable than the corresponding three-dimensional modes for any given set of system parameters. This result is a generalization of the hydrodynamic Squires theorem. An energy-stress theorem indicates that the Maxwell stress is crucial for the growth of the instability. The results of the analysis are consistent with the observed plasma fluctuations with in the limits of using a simple model for the more complex measured jet velocity flow profile. The working gas is singly ionized argon and the jet velocity profile is accurately measured with Doppler shift spectroscopy.

  8. Stratospheric Aerosol and Gas Experiments 1 and 2: Comparisons with ozonesondes

    NASA Technical Reports Server (NTRS)

    Veiga, Robert E.; Cunnold, Derek M.; Chu, William P.; McCormick, M. Patrick

    1995-01-01

    Ozone profiles measured by the Stratospheric Aerosol and Gas Experiments (SAGE) 1 and 2 are compared with ozonesonde profiles at 24 stations over the period extending from 1979 through 1991. Ozonesonde/satellite differences at 21 stations with SAGE 2 overpasses were computed down to 11.5 km in midlatitudes, to 15.5 km in the lower latitudes, and for nine stations with SAGE 1 overpasses down to 15.5 km. The set of individual satellite and ozonesonde profile comparisons most closely colocated in time and space shows mean absolute differences relative to the satellite measurement of 6 +/- 2% for SAGE 2 and 8 +/- 3% for SAGE 1. The ensemble of ozonesonde/satellite differences, when averaged over all altitudes, shows that for SAGE 2, 70% were less than 5%, whereas for SAGE 1, 50% were less than 5%. The best agreement occurred in the altitude region near the ozone density maximum where almost all the relative differences were less than 5%. Most of the statistically significant differences occurred below the ozone maximum down to the tropopause in the region of steepest ozone gradients and typically ranged between 0 and -20%. Correlations between ozone and aerosol extinction in the northern midlatitudes indicate that aerosols had no discernible impact on the ozonesonde/satellite differences and on the SAGE 2 ozone retrieval for the levels of extinction encountered in the lower stratosphere during 1984 to mid-1991.

  9. A comparison of the Stratospheric Aerosol and Gas Experiment II tropospheric water vapor to radiosonde measurements

    SciTech Connect

    Larsen, J.C.; Chiou, E.W. ); Chu, W.P.; McCormick, M.P.; McMaster, L.R. ); Oltmans, S. ); Rind, D. )

    1993-03-20

    Upper tropospheric Stratospheric Aerosol and Gas Experiment II (SAGE II) water vapor observations are compared to correlative radiosonde observations and radiosonde based climatologies. The SAGE II 1987 monthly zonal mean water vapor climatology is compared to both the Global Atmospheric Circulation Statistics (1963-1973) climatology and to the 1987 radiosonde climatology. The clear sky SAGE II climatology is found to be approximately half the level of both the clear/cloudy sky radiosonde climatologies. To determine whether this is realistic for these two different climatologies or includes additional observational and instrumental biases, the authors took the 1987 radiosonde data set and identified approximately 800 correlative profile pairs. The observational biases inherent to SAGE II and the radiosondes produce a set of profile pairs characteristic of clear sky, land conditions. A critical review of the radiosonde measurement capability was carried out to establish the operating range and accuracy in the upper troposphere. The authors show that even with tight coincidence criterion, the quality of the profile pair comparisons varies considerably because of strong water vapor variability occurring on small time and space scales. Annual zonal means calculated from the set of profile pairs again finds SAGE II significantly drier in many latitude bands. Resolving the radiosonde data base by hygrometer type shows this to be true for all hygrometers except for the thin film capacitive type (Vaisala Humicap). For this hygrometer, between 4.5 and 6.5 km SAGE II is drier by approximately 25.%, and from 8.5 to 11.5 km they are nearly equivalent when global annual means are compared. The good agreement with the Vaisala Humicap, currently the most accurate and responsive hygrometer in operational use, suggests existing radiosonde climatologies contain a significant moist bias in the upper troposphere. 31 refs., 16 figs., 6 tabs.

  10. Springtime Arctic Trace Gas Measurements and Comparisons With the Atmospheric Chemistry Experiment on SCISAT

    NASA Astrophysics Data System (ADS)

    Lindenmaier, R.; Batchelor, R.; Strong, K.; Walker, K.; Manney, G.; Daffer, W.

    2009-05-01

    The process of rapid stratospheric ozone loss in the polar regions begins during the polar winter, when dynamical and chemical conditions lead to the formation of reactive chlorine and bromine radicals. Arctic ozone loss varies significantly from year to year because of changing dynamical conditions. Therefore, long-term data sets of Arctic chemical composition measurements are needed to better understand the process of ozone loss, the links between ozone depletion and climate change, and the future evolution of ozone. Solar absorption spectra have been recorded at Eureka, Nunavut in the sunlit part of each year since July 2006, when a Bruker 125HR high-resolution Fourier transform infrared spectrometer was installed at the Polar Environment Atmospheric Research Laboratory (PEARL). Applying the optimal estimation technique, total columns and some vertical profile information are retrieved for a suite of trace gases that are involved in stratospheric ozone depletion. Total columns of O3, HCl, ClONO2, HNO3, and HF will be presented, with a focus on three Canadian Arctic ACE Validation spring campaigns that took place in 2007, 2008, and 2009. Very different dynamical situations were observed over Eureka during these three spring periods: the impact of these conditions on the trace gas measurements will be shown. SCISAT, also known as the Atmospheric Chemistry Experiment (ACE), is a Canadian satellite mission for remote sounding of the Earth's atmosphere and was launched on August 12, 2003. Its primary instrument is a high spectral resolution Fourier Transform Spectrometer (FTS) measuring sequences of atmospheric absorption spectra in solar occultation. From these spectra the vertical distribution of trace gases can be determined. Results of the Bruker 125HR comparisons with the ACE-FTS, made with the purpose of validating the satellite measurements, will be also shown.

  11. The shape of gaseous n-butylbenzene: assessment of computational methods and comparison with experiments.

    PubMed

    Halbert, Stéphanie; Clavaguéra, Carine; Bouchoux, Guy

    2011-06-01

    Conformational landscape of neutral and ionized n-butylbenzene has been examined. Geometries have been optimized at the B3LYP/6-31G(d), B3LYP/6-31+G(d,p), B3LYP-D/6-31+G(d,p), B2PLYP/6-31+G(d,p), B2PLYP-D/6-31+G(d,p), B97-D/6-31+G(d,p), and M06-2X/6-31+G(d,p) levels. This study is complemented by energy computations using 6-311++G(3df,2p) basis set and CBS-QB3 and G3MP2B3 composite methods to obtain accurate relative enthalpies. Five distinguishable conformers have been identified for both the neutral and ionized systems. Comparison with experimentally determined rotational constants shows that the best geometrical parameters are provided by B3LYP-D and M06-2X functionals, which include an explicit treatment of dispersion effects. Composite G3MP2B3 and CBS-QB3 methods, and B2PLYP-D, B3LYP-D, B97-D, and M06-2X functionals, provide comparable relative energies for the two sets of neutral and ionized conformers of butyl benzene. An exception is noted however for conformer V(+) the stability of which being overestimated by the B3LYP-D and B97-D functionals. The better stability of neutral conformers I, III, and IV, and of cation I(+) , demonstrated by our computations, is in perfect agreement with conclusions based on micro wave, fluorescence, and multiphoton ionization experiments.

  12. Comparisons of Transport and Dispersion Model Predictions of the Mock Urban Setting Test Field Experiment

    NASA Astrophysics Data System (ADS)

    Warner, Steve; Platt, Nathan; Heagy, James F.; Jordan, Jason E.; Bieberbach, George

    2006-10-01

    The potential effects of a terrorist attack involving the atmospheric release of chemical, biological, radiological, nuclear, or other hazardous materials continue to be of concern to the United States. The Defense Threat Reduction Agency has developed a Hazard Prediction Assessment Capability (HPAC) that includes initial features to address hazardous releases within an urban environment. Improved characterization and understanding of urban transport and dispersion are required to allow for more robust modeling. In 2001, a scaled urban setting was created in the desert of Utah using shipping containers, and tracer gases were released. This atmospheric tracer and meteorological study is known as the Mock Urban Setting Test (MUST). This paper describes the creation of sets of HPAC predictions and comparisons with the MUST field experiment. Strong consistency between the conclusions of this study and a previously reported HPAC evaluation that relied on urban tracer observations within the downtown area of Salt Lake City was found. For example, in both cases, improved predictions were associated with the inclusion of a simple empirically based urban dispersion model within HPAC, whereas improvements associated with the inclusion of a more computationally intensive wind field module were not found. The use of meteorological observations closest to the array and well above the obstacle array—the sonic anemometer measurements 16 m above ground level—resulted in predictions with the best fit to the observed tracer concentrations. The authors speculate that including meteorological observations or vertical wind profiles above or upwind of an urban region might be a sufficient input to create reasonable HPAC hazard-area predictions.

  13. Tomogram-based comparison of geostatistical models: Application to the Macrodispersion Experiment (MADE) site

    NASA Astrophysics Data System (ADS)

    Linde, Niklas; Lochbühler, Tobias; Dogan, Mine; Van Dam, Remke L.

    2015-12-01

    We propose a new framework to compare alternative geostatistical descriptions of a given site. Multiple realizations of each of the considered geostatistical models and their corresponding tomograms (based on inversion of noise-contaminated simulated data) are used as a multivariate training image. The training image is scanned with a direct sampling algorithm to obtain conditional realizations of hydraulic conductivity that are not only in agreement with the geostatistical model, but also honor the spatially varying resolution of the site-specific tomogram. Model comparison is based on the quality of the simulated geophysical data from the ensemble of conditional realizations. The tomogram in this study is obtained by inversion of cross-hole ground-penetrating radar (GPR) first-arrival travel time data acquired at the MAcro-Dispersion Experiment (MADE) site in Mississippi (USA). Various heterogeneity descriptions ranging from multi-Gaussian fields to fields with complex multiple-point statistics inferred from outcrops are considered. Under the assumption that the relationship between porosity and hydraulic conductivity inferred from local measurements is valid, we find that conditioned multi-Gaussian realizations and derivatives thereof can explain the crosshole geophysical data. A training image based on an aquifer analog from Germany was found to be in better agreement with the geophysical data than the one based on the local outcrop, which appears to under-represent high hydraulic conductivity zones. These findings are only based on the information content in a single resolution-limited tomogram and extending the analysis to tracer or higher resolution surface GPR data might lead to different conclusions (e.g., that discrete facies boundaries are necessary). Our framework makes it possible to identify inadequate geostatistical models and petrophysical relationships, effectively narrowing the space of possible heterogeneity representations.

  14. The Impact of a Comparison Curriculum in Algebra I: A Randomized Experiment

    ERIC Educational Resources Information Center

    Star, Jon R.; Rittle-Johnson, Bethany; Durkin, Kelley; Newton, Kristie; Pollack, Courtney; Lynch, Kathleen; Gogolen, Claire

    2013-01-01

    Comparison is a powerful tool that has been shown to improve learning in a variety of domains. In both laboratory studies and small-scale classroom studies, having learners compare and contrast worked examples has been shown to reliably lead to gains in students' knowledge. Comparison is also integral to "best practices" in mathematics…

  15. Alternating current dielectrophoresis of core-shell nanoparticles: Experiments and comparison with theory

    NASA Astrophysics Data System (ADS)

    Yang, Chungja

    Nanoparticles are fascinating where physical and optical properties are related to size. Highly controllable synthesis methods and nanoparticle assembly are essential for highly innovative technological applications. Well-defined shaped and sized nanoparticles enable comparisons between experiments, theory and subsequent new models to explain experimentally observed phenomena. Among nanoparticles, nonhomogeneous core-shell nanoparticles (CSnp) have new properties that arise when varying the relative dimensions of the core and the shell. This CSnp structure enables various optical resonances, and engineered energy barriers, in addition to the high charge to surface ratio. Assembly of homogeneous nanoparticles into functional structures has become ubiquitous in biosensors (i.e. optical labeling), nanocoatings, and electrical circuits. Limited nonhomogenous nanoparticle assembly has only been explored. Many conventional nanoparticle assembly methods exist, but this work explores dielectrophoresis (DEP) as a new method. DEP is particle polarization via non-uniform electric fields while suspended in conductive fluids. Most prior DEP efforts involve microscale particles. Prior work on core-shell nanoparticle assemblies and separately, nanoparticle characterizations with dielectrophoresis and electrorotation, did not systematically explore particle size, dielectric properties (permittivity and electrical conductivity), shell thickness, particle concentration, medium conductivity, and frequency. This work is the first, to the best of our knowledge, to systematically examine these dielectrophoretic properties for core-shell nanoparticles. Further, we conduct a parametric fitting to traditional core-shell models. These biocompatible core-shell nanoparticles were studied to fill a knowledge gap in the DEP field. Experimental results (chapter 5) first examine medium conductivity, size and shell material dependencies of dielectrophoretic behaviors of spherical CSnp into 2D and

  16. A comparison of Monte-Carlo simulations using RESTRAX and McSTAS with experiment on IN14

    NASA Astrophysics Data System (ADS)

    Wildes, A. R.; S̆aroun, J.; Farhi, E.; Anderson, I.; Høghøj, P.; Brochier, A.

    2000-03-01

    Monte-Carlo simulations of a focusing supermirror guide after the monochromator on the IN14 cold neutron three-axis spectrometer, I.L.L. were carried out using the instrument simulation programs RESTRAX and McSTAS. The simulations were compared to experiment to check their accuracy. Comparisons of the flux ratios over both a 100 and a 1600 mm 2 area at the sample position compare well, and there is a very close agreement between simulation and experiment for the energy spread of the incident beam.

  17. Heat*seq: an interactive web tool for high-throughput sequencing experiment comparison with public data

    PubMed Central

    Devailly, Guillaume; Mantsoki, Anna; Joshi, Anagha

    2016-01-01

    Summary: Better protocols and decreasing costs have made high-throughput sequencing experiments now accessible even to small experimental laboratories. However, comparing one or few experiments generated by an individual lab to the vast amount of relevant data freely available in the public domain might be limited due to lack of bioinformatics expertise. Though several tools, including genome browsers, allow such comparison at a single gene level, they do not provide a genome-wide view. We developed Heat*seq, a web-tool that allows genome scale comparison of high throughput experiments chromatin immuno-precipitation followed by sequencing, RNA-sequencing and Cap Analysis of Gene Expression) provided by a user, to the data in the public domain. Heat*seq currently contains over 12 000 experiments across diverse tissues and cell types in human, mouse and drosophila. Heat*seq displays interactive correlation heatmaps, with an ability to dynamically subset datasets to contextualize user experiments. High quality figures and tables are produced and can be downloaded in multiple formats. Availability and Implementation: Web application: http://www.heatstarseq.roslin.ed.ac.uk/. Source code: https://github.com/gdevailly. Contact: Guillaume.Devailly@roslin.ed.ac.uk or Anagha.Joshi@roslin.ed.ac.uk Supplementary information: Supplementary data are available at Bioinformatics online. PMID:27378302

  18. A Comparison of Students' Clinical Experience in Family Medicine and Traditional Clerkships.

    ERIC Educational Resources Information Center

    Parkerson, George R., Jr.; And Others

    1984-01-01

    Experience on the traditional internal medicine, surgery, pediatrics, obstetrics-gynecology, and psychiatry clerkships was compared with the experience on a family medicine clerkship. The family medicine clerkship offered the most experience with circulatory, respiratory, digestive, neurological, musculoskeletal, and skin problems and with…

  19. Results of small break LOCA experiments in the LOFT reactor system with comparison to code calculations. [PWR

    SciTech Connect

    Adams, J.P.; Linebarger, J.H.; Leach, L.P.

    1980-01-01

    The results are presented of three small break loss-of-coolant experiments performed in the LOFT Pressurized Water Reactor (PWR) system. Experiment L3-0, performed without reactor power, represented a loss of coolant from the power operated relief valve on the top of the pressurizer. Experiments L3-1 and L3-2 were initiated with the reactor at full power (maximum linear heat generation rate approximately 52 kW/m) and represented 4-in and 1-in diameter breaks, respectively, in the reactor inlet piping of a commercial PWR. Comparisons of data to analytical model calculations with a number of different models indicate that most major phenomena were correctly calculated, but that improvements in modeling small break behavior are necessary.

  20. Comparison of Computational Aeroacoustics Prediction of Acoustic Transmission Through a 3D Stator with Experiment

    NASA Technical Reports Server (NTRS)

    Hixon, Ray; Envia, Edmane; Dahl, Milo; Sutliff, Daniel

    2014-01-01

    In this paper, numerical predictions of acoustic transmission through a 3D stator obtained using the NASA BASS code are compared with experimentally measured data. The influence of vane count and stagger as well as frequency and mode order on the transmission loss is investigated. The data-theory comparisons indicate that BASS can predict all the important trends observed in the experimental data.

  1. Comparison of Computational Aeroacoustics Prediction of Acoustic Transmission Through a 3D Stator With Experiment

    NASA Technical Reports Server (NTRS)

    Hixon, Ray; Envia, Edmane; Dahl, Milo; Sutliff, Daniel L.

    2014-01-01

    In this paper, numerical predictions of acoustic transmission through a 3D stator obtained using the NASA BASS code are compared with experimentally measured data. The influence of vane count and stagger as well as frequency and mode order on the transmission loss is investigated. The data-theory comparisons indicate that BASS can predict all the important trends observed in the experimental data.

  2. Estimation of Effect Size from a Series of Experiments Involving Paired Comparisons.

    ERIC Educational Resources Information Center

    Gibbons, Robert D.; And Others

    1993-01-01

    A distribution theory is derived for a G. V. Glass-type (1976) estimator of effect size from studies involving paired comparisons. The possibility of combining effect sizes from studies involving a mixture of related and unrelated samples is also explored. Resulting estimates are illustrated using data from previous psychiatric research. (SLD)

  3. Electron transport and energy degradation in the ionosphere: Evaluation of the numerical solution, comparison with laboratory experiments and auroral observations

    NASA Technical Reports Server (NTRS)

    Lummerzheim, D.; Lilensten, J.

    1994-01-01

    Auroral electron transport calculations are a critical part of auroral models. We evaluate a numerical solution to the transport and energy degradation problem. The numerical solution is verified by reproducing simplified problems to which analytic solutions exist, internal self-consistency tests, comparison with laboratory experiments of electron beams penetrating a collision chamber, and by comparison with auroral observations, particularly the emission ratio of the N2 second positive to N2(+) first negative emissions. Our numerical solutions agree with range measurements in collision chambers. The calculated N(2)2P to N2(+)1N emission ratio is independent of the spectral characteristics of the incident electrons, and agrees with the value observed in aurora. Using different sets of energy loss cross sections and different functions to describe the energy distribution of secondary electrons that emerge from ionization collisions, we discuss the uncertainties of the solutions to the electron transport equation resulting from the uncertainties of these input parameters.

  4. A Comparison of Premenarcheal Expectations and Postmenarcheal Experiences in Chinese Early Adolescents

    ERIC Educational Resources Information Center

    Tang, Catherine So-Kum; Yeung, Dannii Y. L.; Lee, Antoinette Marie

    2004-01-01

    The present study examined Chinese early adolescents' expectations and experiences of their first menstruation. It included 952 participants, 476 premenarcheal and 476 postmenarcheal girls matched by age and by grade level. Results showed that compared to experiences of postmenarcheal girls, premenarcheal girls anticipated more negative emotional…

  5. Comparison of Sexual Experience and Behavior between Bipolar Outpatients and Outpatients without Mood Disorders

    PubMed Central

    Downey, Jennifer; Friedman, Richard C.; Haase, Elizabeth; Goldenberg, David; Bell, Robinette; Edsall, Sidney

    2016-01-01

    Sexual behavior over the past year of 32 outpatients with Bipolar disorder is compared to that of 44 Comparison patients that had never had an episode of affective illness. Subjects were outpatients treated with drugs and psychotherapy in routine office practice. Differences in sexual behavior between the two groups as a whole were minimal, but meaningful differences emerged when subgroups were compared. Compared to control men, Bipolar men had had more partners in the last year and were more likely to have had sex without condoms. Compared to Bipolar females, Bipolar males had more sex partners, had more sex with strangers, and were more likely to have engaged in homosexual behavior. Even so, some patients in the Comparison group also had engaged in risky sexual behavior. They had failed to use condoms and had had sex with strangers and prostitutes during the previous year. PMID:27190984

  6. Flight/ground sample comparison relating to flight experiment M552, exothermic brazing

    NASA Technical Reports Server (NTRS)

    Heine, R. W.; Adams, C. M.; Siewert, T. A.

    1973-01-01

    Comparisons were made between Skylab and ground-based specimens of nickel and stainless steel which were vacuum brazed using silver-copper-lithium alloy with various joint configurations. It was established that the absence of gravity greatly extends the scope of brazing since capillary flow can proceed without gravity interference. There was also evidence of enhanced transport, primarily in that liquid silver copper alloy dissolves nickel to a much greater extent in the zero gravity environment.

  7. Comparison of DNS Determination of the Dynamics of Vortex Rings in Viscous Fluids and Experiment

    NASA Astrophysics Data System (ADS)

    Donnelly, Russell; Hershberger, Robert

    2009-11-01

    We have been studying vortex rings in water for some time [1] and recently became aware of an important paper studying vortex rings by direct numerical simulation (DNS) from Coleman's group at Southampton [2]. There is clearly much to be learned from a comparison of the results in [1] and [2]. The first insight is a comparison of slowing vortex rings, where we find quite similar decay rates at comparable Reynolds numbers. A second insight is gained by noting that they find a time t* needs to elapse before the core adjusts to its vorticity distribution. We find photographically that the ring needs to propagate at least one gun diameter before it adjusts its vorticity. A third insight is that the rings in Fig. 5(b) of [2] do not change much in radius, consistent with the results in Table 2 of our paper [1]. The talk will cover more recent comparisons of the two works including observations of the growth of vortex waves.[4pt] [1] I. S. Sullivan, J. J. Niemela, R. Hershberger, D. Bolster and R. J. Donnelly, J. Fluid Mech. 609 319 (2008).[0pt] [2] P. J. Archer, T. G. Thomas and G. N. Coleman, J. Fluid Mech.598 201 (2008).

  8. Cognitive Experiences Reported by Borderline Patients and Axis II Comparison Subjects: A 16-year Prospective Follow-up Study

    PubMed Central

    Zanarini, Mary C.; Frankenburg, Frances R.; Wedig, Michelle M.; Fitzmaurice, Garrett M.

    2013-01-01

    Objective This study assesses three main types of cognition: nonpsychotic thought (odd thinking, unusual perceptual experiences, and non-delusional paranoia), quasi-psychotic thought, and true-psychotic thought in borderline patients followed prospectively for 16 years. It also compares the rates of these disturbed cognitions to those reported by axis II comparison subjects. Method The cognitive experiences of 362 inpatients—290 borderline patients and 72 axis II comparison subjects—were assessed at study entry using the cognitive section of the Revised Diagnostic Interview for Borderlines. Their cognitive experiences were reassessed every two years using the same interview. Results Each of the five main types of thought studied was reported by a significantly higher percentage of borderline patients than axis II comparison subjects over time. Each of these types of thought, except true-psychotic thought, declined significantly over time for those in both groups. Eleven of the 17 more specific forms of thought studied were also reported by a significantly higher percentage of borderline patients over the years of follow-up: magical thinking, overvalued ideas, recurrent illusions, depersonalization, derealization, undue suspiciousness, ideas of reference, other paranoid ideation, quasi-psychotic delusions, quasi-psychotic hallucinations, and true-psychotic hallucinations. Fourteen specific forms of thought were found to decline significantly over time for those in both groups: all forms of thought mentioned above except true-psychotic hallucinations plus marked superstitiousness, sixth sense, telepathy, and clairvoyance. Conclusions Disturbed cognitions are common among borderline patients and distinguishing for the disorder. They also decline substantially over time but remain a problem, particularly those of a nonpsychotic nature. PMID:23558452

  9. A comparison of the effects of prejob training and job experience on nonprofessional telephone crisis counselors.

    PubMed

    Elkins, R L; Cohen, C R

    1982-01-01

    This study, carried out in a telephone crisis intervention program in which nonprofessional volunteer counselors received 55 hours of prejob training, isolates the effects of prejob training and on-the-job experience. Participants in the study were evaluated on several parameters including knowledge, counseling skills, acceptance of others, and dogmatism. Three groups of volunteers were measured: group 1--measured immediately before and after prejob training, group 2--measured just after prejob training, and group 3--measured after five months of telephone counseling experience. Results indicate that counselor skills and knowledge significantly increased with prejob training, but did not show further improvement as a result of five months of experience. Attitudes such as acceptance of others and dogmatism did not change either as a result of training or experience. Dogmatism was found to be inversely related to both counselor skill and knowledge.

  10. Systematic Ion Irradiation Experiments to Olivine: Comparison with Space Weathered Rims of Itokawa Regolith Particles

    NASA Astrophysics Data System (ADS)

    Matsumoto, T.; Tsuchiyama, A.; Watanabe, N.; Yasuda, K.; Miyake, A.; Nakauchi, Y.; Okada, T.; Abe, M.; Yada, T.; Uesugi, M.; Karouji, Y.; Nakato, A.; Hashiguschi, M.; Kumagai, K.

    2015-11-01

    We performed H and He ion irradiation experiments using olivine fragments, in order to reveal formation time-scales of space weathered rims and formation processes of blisters by solar wind irradiation.

  11. Results of GEANT simulations and comparison with first experiments at DANCE.

    SciTech Connect

    Reifarth, R.; Bredeweg, T. A.; Browne, J. C.; Esch, E. I.; Haight, R. C.; O'Donnell, J. M.; Kronenberg, A.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.

    2003-07-29

    This report describes intensive Monte Carlo simulations carried out to be compared with the results of the first run cycle with DANCE (Detector for Advanced Neutron Capture Experiments). The experimental results were gained during the commissioning phase 2002/2003 with only a part of the array. Based on the results of these simulations the most important items to be improved before the next experiments will be addressed.

  12. Comparison of monometal and multimetal adsorption in Mississippi River alluvial wetland sediment: batch and column experiments.

    PubMed

    Seo, Dong Cheol; Yu, Kewei; DeLaune, Ronald D

    2008-12-01

    Monometal and multimetal adsorption of selected heavy metals in a sediment from a coastal Louisiana forested swamp used for wastewater treatment was studied. Results from the batch experiments show that the maximum adsorption capacities of the metals by the sediment were in the order of Pb>Hg>Cr>CdCuZn>As based on monometal adsorption isotherm, and Hg>Cr>CuCd approximately Pb>As approximately Zn based on multimetal adsorption isotherm, respectively. Batch experimental data best fit the Langmuir model rather than the Freundlich isotherms. In the column experiments, the maximum adsorption capacities of the metals were in the order of Pb>Hg>Cr>Cd>Cu>Zn>As in monometal conditions, and Hg>Cr>Pb>CuZn approximately Cd>As in multimetal conditions. The metals became more mobile in multimetal than in monometal conditions. Results from both the batch and column experiments show that competitive adsorption among metals increases the mobility of these metals. Particularly, in this study, Pb in multimetal conditions lost it adsorption capacity most significantly. In both monometal and multimetal conditions, the maximum adsorption capacity of the metals in the column experiments was higher than that in the batch experiment indicating other metal retention mechanisms rather than adsorption may be involved. Therefore, both column and batch experiments are needed for estimating retention capacities and removal efficiencies of metals in sediments.

  13. Comparison of Resource Requirements for a Wind Tunnel Test Designed with Conventional vs. Modern Design of Experiments Methods

    NASA Technical Reports Server (NTRS)

    DeLoach, Richard; Micol, John R.

    2011-01-01

    The factors that determine data volume requirements in a typical wind tunnel test are identified. It is suggested that productivity in wind tunnel testing can be enhanced by managing the inference error risk associated with evaluating residuals in a response surface modeling experiment. The relationship between minimum data volume requirements and the factors upon which they depend is described and certain simplifications to this relationship are realized when specific model adequacy criteria are adopted. The question of response model residual evaluation is treated and certain practical aspects of response surface modeling are considered, including inference subspace truncation. A wind tunnel test plan developed by using the Modern Design of Experiments illustrates the advantages of an early estimate of data volume requirements. Comparisons are made with a representative One Factor At a Time (OFAT) wind tunnel test matrix developed to evaluate a surface to air missile.

  14. Mothers with intellectual disability, their experiences of maltreatment, and their children's attachment representations: a small-group matched comparison study.

    PubMed

    Granqvist, Pehr; Forslund, Tommie; Fransson, Mari; Springer, Lydia; Lindberg, Lene

    2014-01-01

    Maternal intellectual disability (ID) is regarded a risk factor in child development, but there is no scientific evidence on maternal ID in relation to children's attachment. Using a matched comparison design, a small group (n = 23) of mothers diagnosed with ID was studied to help fill this gap. Besides maternal ID, we examined the role of abuse/trauma/maltreatment (ATM) in the mothers' biographies, along with potential confounds. Comparison group mothers (n = 25) had normal variations in intelligence and matched mothers with ID on residential area, income, child age, and sex. History of maternal ATM was assessed using a semi-structured interview and was found to be significantly more likely in the ID group mothers' experience than the comparison group mothers. Children's (M age = 77 months) attachment representations were assessed with the Separation Anxiety Test. Among children of mothers with ID, a substantial minority (35%) had a secure and the vast majority (>80%) an organized attachment representation. Mothers with ID who had suffered elevated ATM were significantly more likely to have children who were scored high on disorganization and insecurity. We discuss possible implications of our findings for societal considerations regarding parenting and child attachment in the context of parental ID status.

  15. Comparison of an unsaturated soil zone model (SESOIL) predictions with a laboratory leaching experiment

    SciTech Connect

    Hetrick, D.M.; Travis, C.C.; Kinerson, R.S.

    1988-01-01

    Model predictions of a modified version of the soil compartment model SESOIL are compared with laboratory measurements of pollutant transport in soil. A brief description of SESOIL is given and modifications that have been made to the model are summarized. Comparisons are performed using data from a laboratory soil column study involving six chemicals (dicamba, 2,4-dichlorophenoxyacetic acid, atrazine, diazinon, pentachlorophenol, and lindane). Overall, SESOIL model predictions are in good agreement with the empirical data. Limitation of the model are discussed. 15 refs., 2 figs., 3 tabs.

  16. Discussion of comparison study of hydraulic fracturing models -- Test case: GRI Staged Field Experiment No. 3

    SciTech Connect

    Cleary, M.P.

    1994-02-01

    This paper provides comments to a companion journal paper on predictive modeling of hydraulic fracturing patterns (N.R. Warpinski et. al., 1994). The former paper was designed to compare various modeling methods to demonstrate the most accurate methods under various geologic constraints. The comments of this paper are centered around potential deficiencies in the former authors paper which include: limited actual comparisons offered between models, the issues of matching predictive data with that from related field operations was lacking or undocumented, and the relevance/impact of accurate modeling on the overall hydraulic fracturing cost and production.

  17. A Comparison of Theory and Experiment for High-speed Free-molecule Flow

    NASA Technical Reports Server (NTRS)

    Stalder, Jackson R; Goodwin, Glen; Creager, Marcus O

    1951-01-01

    A comparison is made of free-molecule-flow theory with the results of wind-tunnel tests performed to determine the drag and temperature-rise characteristics of a transverse circular cylinder. The measured values of the cylinder center-point temperature confirmed the salient point of the heat-transfer analysis which was the prediction that an insulated cylinder would attain a temperature higher than the stagnation temperature of the stream. Good agreement was obtained between the theoretical and the experimental values for the drag coefficient.

  18. Conceptual change in an organic chemistry laboratory: A comparison of computer simulations and traditional laboratory experiments

    NASA Astrophysics Data System (ADS)

    Gaddis, Barbara A.

    2001-12-01

    This quasi-experimental research study examined the effect of computer simulations and hands-on laboratory experiments in enhancing conceptual understanding and alleviating misconceptions of organic chemistry reaction mechanisms. Subjects were sixty-nine sophomore-level organic chemistry students enrolled in four laboratory sections. Laboratory sections were stratified across instructor and randomly assigned to serve as a control or treatment laboratory. Students in the control group performed all hands-on experiments. Students in the treatment group performed hands-on experiments for the first and last part of the semester but performed computer simulations for a five-week period in the middle of the semester. Prior to treatment, groups were equivalent with respect to academic orientation, motivation, formal reasoning ability, and spatial visualization ability. Fifteen common misconceptions held by beginning organic chemistry students were identified from the Covalent Bonding and Structures Test. At the end of the semester, thirteen of these misconceptions persisted. Molecular geometry was the only category of misconceptions that significantly improved as a result of computer simulations, F(1,58) = 6.309, p = .015. No significant differential change was observed in misconceptions about bond polarity, molecular polarity, intermolecular forces, lattice structures, or the octet rule. Computer simulations were found to result in significantly greater conceptual understanding of organic chemistry reactions on two of the experiments, Stereochemistry, F(1,55) = 6.174, p = .016, and Nucleophilic Substitution, F(1,57) = 6.093, p = .017. The other three experiments, Infrared Spectroscopy, Elimination, and Oxymercuration, did not show a significant differential effect between types of laboratory experiences. No significant differences were observed on long-term retention of concepts. Overall conclusions from the study are that neither computer simulations nor hands

  19. Direct Numerical Simulation of Fracture Behaviour for Random Short Wood Fibres Reinforced Composites, Comparison with Digital Image Correlation Experiments

    NASA Astrophysics Data System (ADS)

    Shen, M.; Touchard, F.; Bezine, G.; Brillaud, J.

    2010-06-01

    The work is to predict fracture behaviour of bio-composites from the tensile properties of its components. In this work, we have realized a direct numerical simulation of fracture behaviour for random short spruce fibers reinforced composites. For calculations, wood fibers have been considered as linear elastic bodies, polypropylene matrix as an elastic-plastic material. Then, numerical results have been compared with experimental results that have been obtained by digital image correlation. This comparison indicates that random fiber FE model of random short spruce fibers reinforced composites can be able to fairly reflect the influence of random fibers microstructure in the composite on its fracture behavior. The calculation of both random fiber and homogeneous FE model and their comparison with experiments show that the average values of J-integral in a region in the front of the crack tip from both numerical FE models are in good agreement with the average J value of DIC experiment in the same region when the numerical and experimental CT specimens of the short spruce fiber reinforced composite are subjected to the same extension at their loading point.

  20. Comparison of Properties of Solid Lubricant Between Two Exposure Experiments Aboard the ISS

    NASA Astrophysics Data System (ADS)

    Matsumoto, Koji; Suzuki, Mineo; Kimoto, Yugo

    To evaluate the degradation of materials in low Earth orbit space environment, the Space Environment Exposure Device (SEED) experiments were carried out on the International Space Station. As part of these experiments, changes in the tribological properties of a molybdenum disulfide bonded film that is used as a solid lubricant, were evaluated. The results of friction tests in a vacuum and surface analysis by XPS were compared between two exposure experiments aboard the Service Module (SM) and the Japan Experimental Module (JEM). The investigations revealed silicon and fluorine contaminations in the JEM/SEED flight sample, but with a lower amount of silicon contamination than the SM/SEED flight sample. The JEM/SEED flight sample and ground-based tested samples showed lower friction coefficients than a reference sample at the beginning of the tests. The friction behavior of the JEM/SEED flight sample was similar to those of SM/SEED flight samples.

  1. Is it really so bad? A comparison of positive and negative experiences in Antarctic winter stations

    NASA Technical Reports Server (NTRS)

    Wood, J.; Hysong, S. J.; Lugg, D. J.; Harm, D. L.

    2000-01-01

    This study examined the range of positive and negative themes reported by 104 Australian Antarctic winter personnel at four stations during two austral winters. Reports from the expeditioners were subjected to a content analysis using the TextSmart software from SPSS, Inc. Results indicated that, although the list of negative experiences is lengthy, most events are relatively rare. On the other hand, although the list of positive experiences is short, the frequencies with which they are reported are much greater than for most of the problems. Possible explanations for these themes and for future directions are discussed.

  2. Evaluation of the biocompatibility of NiTi dental wires: a comparison of laboratory experiments and clinical conditions.

    PubMed

    Toker, S M; Canadinc, D

    2014-07-01

    Effects of intraoral environment on the surface degradation of nickel-titanium (NiTi) shape memory alloy orthodontic wires was simulated through ex situ static immersion experiments in artificial saliva. The tested wires were compared to companion wires retrieved from patients in terms of chemical changes and formation of new structures on the surface. Results of the ex situ experiments revealed that the acidic erosion effective at the earlier stages of immersion led to the formation of new structures as the immersion period approached 30 days. Moreover, comparison of these results with the analysis of wires utilized in clinical treatment evidenced that ex situ experiments are reliable in terms predicting C-rich structure formation on the wire surfaces. However, the formation of C pileups at the contact sites of arch wires and brackets could not be simulated with the aid of static immersion experiments, warranting the simulation of the intraoral environment in terms of both chemical and physical conditions, including mechanical loading, when evaluating the biocompatibility of NiTi orthodontic arch wires.

  3. A Comparison Between Girls' and Boys' Experiences of Unwanted Sexual Behaviour in Secondary Schools

    ERIC Educational Resources Information Center

    Timmerman, Greetje

    2005-01-01

    Background: This study examines gender differences (and similarities) in the context, meaning and effects of unwanted sexual behaviour in secondary schools. Purpose First, the study's purpose is exploration of variables that discriminate between girls' and boys' experiences of unwanted sexual behaviour. Secondly, the aim is to find empirical…

  4. Statistical comparison between experiments and numerical simulations of shock-accelerated gas cylinders

    SciTech Connect

    Rider, William; Kamm, J. R.; Zoldi, C. A.; Tomkins, C. D.

    2002-01-01

    We present detailed spatial analysis comparing experimental data and numerical simulation results for Richtmyer-Meshkov instability experiments of Prestridge et al. and Tomkins et al. These experiments consist, respectively, of one and two diffuse cylinders of sulphur hexafluoride (SF{sub 6}) impulsively accelerated by a Mach 1.2 shockwave in air. The subsequent fluid evolution and mixing is driven by the deposition of baroclinic vorticity at the interface between the two fluids. Numerical simulations of these experiments are performed with three different versions of high resolution finite volume Godunov methods, including a new weighted adaptive Runge-Kutta (WARK) scheme. We quantify the nature of the mixing using using integral measures as well as fractal analysis and continuous wavelet transforms. Our investigation of the gas cylinder configurations follows the path of our earlier studies of the geometrically and dynamically more complex gas 'curtain' experiment. In those studies, we found significant discrepancies in the details of the experimentally measured mixing and the details of the numerical simulations. Here we evaluate the effects of these hydrodynamic integration techniques on the diffuse gas cylinder simulations, which we quantitatively compare with experimental data.

  5. A COMPARISON OF PARTICLE MASS SPECTROMETERS DURING THE 1999 ATLANTA SUPERSITES EXPERIMENT

    EPA Science Inventory

    During the Atlanta SuperSite Experiment, four particle mass spectrometers were operated together for the first time: NOAA's PALMS (Particle Analysis by Laser Mass Spectrometry), U. C. Riverside's ATOFMS (Aerosol Time-of-Flight Mass Spectrometry), U. Delaware's RSMS-II (Rapid Si...

  6. Incidental Becomes Visible: A Comparison of School- and Community-Based Field Experience Narratives

    ERIC Educational Resources Information Center

    Holder, K. C.; Downey, Jayne A.

    2008-01-01

    The purpose of this study was to describe and compare student learning documented using written field experience summary narratives and occurring in community-based or school-based locations. Utilizing a hybrid portraiture--instrumental case study design, two researchers selected participants from undergraduate educational psychology courses using…

  7. Preservice Teachers' Reflection on Clinical Experiences: A Comparison of Blog and Final Paper Assignments

    ERIC Educational Resources Information Center

    Harland, Darci J.; Wondra, Joshua D.

    2011-01-01

    This study focused on the depth of reflection in the writing of preservice teachers who completed end-of-the-semester reflective papers or reflective blogs for undergraduate education courses associated with clinical experiences. Coders rated the depth of reflection as one of four categories: non-reflection, understanding, reflection, or critical…

  8. A Comparison of Internal Dispositions and Career Trajectories after Collaborative versus Apprenticed Research Experiences for Undergraduates

    ERIC Educational Resources Information Center

    Frantz, Kyle J.; Demetrikopoulos, Melissa K.; Britner, Shari L.; Carruth, Laura L.; Williams, Brian A.; Pecore, John L.; DeHaan, Robert L.; Goode, Christopher T.

    2017-01-01

    Undergraduate research experiences confer benefits on students bound for science, technology, engineering, and mathematics (STEM) careers, but the low number of research professionals available to serve as mentors often limits access to research. Within the context of our summer research program (BRAIN), we tested the hypothesis that a team-based…

  9. A Comparison of Ionic and Covalent Iodine Dihalides: An Integrated Experiment.

    ERIC Educational Resources Information Center

    Woolf, Alfred A.

    1978-01-01

    Compares the preparation and decomposition of potassium dibromoiodate and of phenyl iodine dichloride in a flexible experiment which accustoms the student to handle halogens, to test for halogens in mixtures, and to appreciate the difference between thermodynamic and kinetic control of reactions. (Author/MA)

  10. Dynamically correlated spontaneous-emission laser: theory and comparison with experiment

    SciTech Connect

    Bergou, J.; Orszag, M.

    1988-02-01

    A higher-order correlated-emission laser (CEL) effect is found theoretically in a Doppler-broadened medium. A full quantum-mechanical account of the CEL in the nonlinear regime shows a large reduction in the beat-signal linewidth. This behavior is confirmed by a recent experiment.

  11. Analysing chemical-induced changes in macroinvertebrate communities in aquatic mesocosm experiments: a comparison of methods.

    PubMed

    Szöcs, Eduard; Van den Brink, Paul J; Lagadic, Laurent; Caquet, Thierry; Roucaute, Marc; Auber, Arnaud; Bayona, Yannick; Liess, Matthias; Ebke, Peter; Ippolito, Alessio; ter Braak, Cajo J F; Brock, Theo C M; Schäfer, Ralf B

    2015-05-01

    Mesocosm experiments that study the ecological impact of chemicals are often analysed using the multivariate method 'Principal Response Curves' (PRCs). Recently, the extension of generalised linear models (GLMs) to multivariate data was introduced as a tool to analyse community data in ecology. Moreover, data aggregation techniques that can be analysed with univariate statistics have been proposed. The aim of this study was to compare their performance. We compiled macroinvertebrate abundance datasets of mesocosm experiments designed for studying the effect of various organic chemicals, mainly pesticides, and re-analysed them. GLMs for multivariate data and selected aggregated endpoints were compared to PRCs regarding their performance and potential to identify affected taxa. In addition, we analysed the inter-replicate variability encountered in the studies. Mesocosm experiments characterised by a higher taxa richness of the community and/or lower taxonomic resolution showed a greater inter-replicate variability, whereas variability decreased the more zero counts were encountered in the samples. GLMs for multivariate data performed equally well as PRCs regarding the community response. However, compared to first axis PRCs, GLMs provided a better indication of individual taxa responding to treatments, as separate models are fitted to each taxon. Data aggregation methods performed considerably poorer compared to PRCs. Multivariate community data, which are generated during mesocosm experiments, should be analysed using multivariate methods to reveal treatment-related community-level responses. GLMs for multivariate data are an alternative to the widely used PRCs.

  12. Career Decisions and Experiences of Social Work Faculty: A Gender Comparison

    ERIC Educational Resources Information Center

    Holley, Lynn C.; Young, Diane S.

    2005-01-01

    This study uses quantitative and qualitative findings from a mail and online questionnaire to examine the experiences and perspectives of 76 doctoral-degreed social work faculty about the factors that affected their career decisions. The authors discuss similarities and differences between women and men in job-related decision making. Respondent…

  13. A Comparison of Methods to Test for Mediation in Multisite Experiments

    ERIC Educational Resources Information Center

    Pituch, Keenan A.; Whittaker, Tiffany A.; Stapleton, Laura M.

    2005-01-01

    A Monte Carlo study extended the research of MacKinnon, Lockwood, Hoffman, West, and Sheets (2002) for single-level designs by examining the statistical performance of four methods to test for mediation in a multilevel experimental design. The design studied was a two-group experiment that was replicated across several sites, included a single…

  14. Early Learning Experience and Adolescent Anxiety: A Cross-Cultural Comparison between Japan and England

    ERIC Educational Resources Information Center

    Essau, Cecilia A.; Ishikawa, Shin-ichi; Sasagawa, Satoko

    2011-01-01

    The main aim of this study was to compare the frequency of anxiety symptoms among adolescents in Japan and England, and to examine the association between early learning experiences and anxiety symptoms. A total of 299 adolescents (147 from England and 152 from Japan), aged 12 to 17 years were investigated. Results showed that adolescents in…

  15. Comparison between experimental and theoretical conjugate points locations in the Araks experiments

    NASA Astrophysics Data System (ADS)

    Izhovkina, N. I.; Zhulin, I. A.; Kosik, J. C.; Piatsi, A. Kh.; Sverdlov, Iu. L.; Uspenskii, M. V.; Zarnitskii, Iu. F.; Reme, H.; Saint-Marc, A.; Vigo, J. M.

    1980-09-01

    In this paper the results of the conjugate point experiments conducted with the Araks rockets are presented. These results are compared to conjugate point calculations using experimental and theoretical models of the magnetosphere. For the first flight good agreement is found in latitude. The agreement is not as good for the second flight when the local geomagnetic conditions were disturbed.

  16. Field Experience Supervision: A Comparison of Cooperating Teachers' and College Supervisors' Evaluations of Student Teachers

    ERIC Educational Resources Information Center

    Hunn, Lorie L.

    2009-01-01

    This study explored and compared the ways in which school-based cooperating teachers and college supervisors evaluate student teachers. The scores allocated to student teachers by school-based cooperating teachers and college supervisors in the final field experience evaluations of student teachers were analyzed. A mixed methods research design…

  17. Chinese Students' Science-Related Experiences: Comparison of the ROSE Study in Xinjiang and Shanghai

    ERIC Educational Resources Information Center

    Yeung, Yau-yuen; Li, Yufeng

    2015-01-01

    Background: Students' daily-life experiences may render favorable effects on the students' affective domain like interest, enthusiasm, motivation, joy, curiosity, awareness, and eagerness to learn science as not commonly found in the classroom environment. However, no rigorous research has been reported on those aspects in Mainland China despite…

  18. The drag of airplane radiators with special reference to air heating : comparison of theory and experiment

    NASA Technical Reports Server (NTRS)

    Gothert, B

    1939-01-01

    This report contains a survey of past radiator research. This report also is intended as a systematic comparison of theoretical and experimental radiator drag, with the object of ascertaining the most important loss sources and their interaction in different cases of installation, and to separate the radiator systems which are amenable to calculation, both as regards axial flow and drag. The sources of loss due to the diffuser are to be looked into closely as in many cases they can be of preeminent magnitude and their customary appraisal, according to Fliegner's formula, does not meet actual conditions. Besides, generally applicable equations and charts are developed for the rapid determination of the heating effect of radiators as regards flow and drag, and then checked by routine tests on hot radiators.

  19. Comparison of seismic and hydrodynamic yield determinations for the Soviet joint verification experiment of 1988

    PubMed Central

    Sykes, Lynn R.; Ekström, Göran

    1989-01-01

    Seismic magnitudes determined from surface and body waves for the Soviet underground nuclear explosion of September 14, 1988, are used to calculate the yield of that event from previously derived calibration curves. The yield obtained by combining the two seismic estimates is 113 kilotons, which is very close to those obtained by hydrodynamic measurements made on-site. This comparison substantiates previous conclusions about the sizes of past Soviet weapons tests and compliance with the Threshold Test Ban Treaty. The factor of uncertainty in the combined seismic yield is 1.28 at the 68% and 1.62 at the 95% confidence levels, demonstrating that accuracies considerably better than a factor of 2 can be obtained by combining seismic determinations of yield. PMID:16594040

  20. Very high resolution optical transition radiation imaging system: Comparison between simulation and experiment

    NASA Astrophysics Data System (ADS)

    Bolzon, B.; Aryshev, A.; Aumeyr, T.; Boogert, S.; Karataev, P.; Kruchinin, K. O.; Lefevre, T.; Mazzoni, S.; Nevay, L.; Shevelev, M.; Terunuma, N.; Urakawa, J.; Welsch, C. P.

    2015-08-01

    Optical transition radiation (OTR) has become a commonly used method for 2D beam imaging measurements. In the Accelerator Test Facility 2 (ATF2) at KEK, beam sizes smaller than the OTR point spread function have been measured. Simulations of the OTR imaging system have been performed using the ZEMAX software to study the effects of optical errors such as aberrations, diffraction, and misalignments of optical components. This paper presents a comparison of simulations of the OTR point spread function with experimental data obtained at ATF2. It shows how the quantification and control of optical errors impacts on optimizing the resolution of the system. We also show that the OTR point spread function needs to be predicted accurately to optimize any optical system and to predict the error made on measurement.

  1. Comparison between experiments and Large-Eddy Simulations of tip spiral structure and geometry

    NASA Astrophysics Data System (ADS)

    Ivanell, S.; Leweke, T.; Sarmast, S.; Quaranta, H. U.; Mikkelsen, R. F.; Sørensen, J. N.

    2015-06-01

    Results from Large-Eddy Simulations using the actuator line technique have been validated against experimental results. The experimental rotor wake, which forms the basis for the comparison, was studied in a recirculating free-surface water channel, where a helical vortex was generated by a single-bladed rotor mounted on a shaft. An investigation of how the experimental blade geometry and aerofoil characteristics affect the results was performed. Based on this, an adjustment of the pitch setting was introduced, which is still well within the limits of the experimental uncertainty. Excellent agreement between the experimental and the numerical results was achieved concerning the circulation, wake expansion and pitch of the helical tip vortex. A disagreement was found regarding the root vortex position and the axial velocity along the centre line of the tip vortex. This work establishes a good base for further studies of more fundamental stability parameters of helical rotor wakes.

  2. A comparison of sexual coercion experiences reported by men and women in prison.

    PubMed

    Struckman-Johnson, Cindy; Struckman-Johnson, David

    2006-12-01

    Comparisons were made between self-reports from 382 men and 51 women who had experienced sexual coercion while incarcerated. Victim data were obtained from a sample of 1,788 male inmates and 263 female inmates who responded to an anonymous written survey distributed in 10 midwestern prisons. Men reported that their perpetrators in worst-case incidents were inmates (72%), staff (8%), or inmates and staff collaborating (12%). Women reported that their perpetrators were inmates (47%) and staff (41%). Greater percentages of men (70%) than women (29%) reported that their incident resulted in oral, vaginal, or anal sex. More men (54%) than women (28%) reported an incident that was classified as rape. Men and women were similar in feeling depression; however, more men (37%) than women (11%) reported suicidal thoughts and suicide attempts (19% for men, 4% for women). Implications of results for prevention of sexual coercion in prison are discussed.

  3. Temporal and latitudinal variations of stratospheric trace gases - A critical comparison between theory and experiment

    NASA Technical Reports Server (NTRS)

    Wofsy, S. C.

    1978-01-01

    Global calculations of stratospheric HOx, Clx, and NOx are presented which include the effects of planetary albedo and diurnal and seasonal variations of the insolation. Comparisons are made with a wide range of atmospheric measurements at different latitudes and altitudes. Agreement between theory and observations is generally within a factor of 2. The theory appears to explain adequately the major features of latitude and seasonal distributions of NO2 and HNO3. The results indicate that mesospheric OH makes an appreciable contribution to the total OH column abundance and strongly suggest that nitrogen oxides exist principally in the form of HNO3 at high latitudes in winter. There are difficulties in reconciling OH, ClO, and O3 observations in the upper stratosphere.

  4. Online Sexual Activity Experiences Among College Students: A Four-Country Comparison.

    PubMed

    Döring, Nicola; Daneback, Kristian; Shaughnessy, Krystelle; Grov, Christian; Byers, E Sandra

    2015-12-10

    The purpose of this study was to compare male and female college students in four countries (Canada, Germany, Sweden, and the U.S.) on their lifetime experiences (prevalence) and frequency of recent experiences with six types of online sexual activities (OSA): sexual information, sexual entertainment, sexual contacts, sexual minority communities, sexual products, and sex work. Participants (N = 2690; M age, 24.65 years; 53.4 % women, 46.6 % men) were recruited from a university in each of the countries to complete an online survey that included background and demographic questions, and questions about OSA. Most participants reported experience with accessing sexual information (89.8 %) and sexual entertainment (76.5 %) online. Almost half (48.5 %) reported browsing for sexual products, and a substantial minority reported having engaged in cybersex (30.8 %). Very few participants (1.1 %) paid for online sexual services or received payment (0.5 %). In general, participants showed relatively infrequent experience with all types of OSA within the last 3 months. Men showed both higher prevalence and frequency of use of sexually stimulating material online than did women. However, this gender gap was smaller than in previous studies. Country and gender by country effects were (with one exception) either very small or non-existent, suggesting that, overall, students in the four countries were similar in their OSA experiences. Results are discussed in light of an emerging global net generation and globalized sexual culture.

  5. Comprehensive comparisons of geodesic acoustic mode characteristics and dynamics between Tore Supra experiments and gyrokinetic simulations

    SciTech Connect

    Storelli, A. Vermare, L.; Hennequin, P.; Gürcan, Ö. D.; Singh, Rameswar; Morel, P.; Dif-Pradalier, G.; Sarazin, Y.; Garbet, X.; Grandgirard, V.; Ghendrih, P.; Görler, T.

    2015-06-15

    In a dedicated collisionality scan in Tore Supra, the geodesic acoustic mode (GAM) is detected and identified with the Doppler backscattering technique. Observations are compared to the results of a simulation with the gyrokinetic code GYSELA. We found that the GAM frequency in experiments is lower than predicted by simulation and theory. Moreover, the disagreement is higher in the low collisionality scenario. Bursts of non harmonic GAM oscillations have been characterized with filtering techniques, such as the Hilbert-Huang transform. When comparing this dynamical behaviour between experiments and simulation, the probability density function of GAM amplitude and the burst autocorrelation time are found to be remarkably similar. In the simulation, where the radial profile of GAM frequency is continuous, we observed a phenomenon of radial phase mixing of the GAM oscillations, which could influence the burst autocorrelation time.

  6. Numerical simulations of spark channels propagating along the ground surface: Comparison with high-current experiment

    SciTech Connect

    Bazelyan, E. M.; Sysoev, V. S.; Andreev, M. G.

    2009-08-15

    A numerical model of a spark discharge propagating along the ground surface from the point at which an {approx}100-kA current pulse is input into the ground has been developed based on experiments in which the velocity of a long leader was measured as a function of the leader current. The results of numerical simulations are in good agreement with the measured characteristics of creeping discharges excited in field experiments by using a high-power explosive magnetic generator. The reason why the length of a spark discharge depends weakly on the number of simultaneously developing channels is found. Analysis of the influence of the temporal characteristics of the current pulse on the parameters of the creeping spark discharge shows that actual lighting may exhibit similar behavior.

  7. A comparison of older adults' subjective experience with virtual and real environments during dynamic balance activities

    PubMed Central

    Proffitt, Rachel; Lange, Belinda; Chen, Christina; Winstein, Carolee

    2014-01-01

    The purpose of this study was to explore the subjective experience of older adults interacting with both virtual and real environments. Thirty healthy older adults engaged with real and virtual tasks of similar motor demands: reaching to a target in standing and stepping stance. Immersive tendencies and absorption scales were administered before the session. Game engagement and experience questionnaires were completed after each task, followed by a semi-structured interview at the end of the testing session. Data were analyzed respectively using paired t-tests and grounded theory methodology. Participants preferred the virtual task over the real task. They also reported an increase in presence and absorption with the virtual task, describing an external focus of attention. Findings will be used to inform future development of appropriate game-based balance training applications that could be embedded in the home or community settings as part of evidence-based fall prevention programs. PMID:24334299

  8. A comparison of scoring systems and level of scorer experience on the Bender-Gestalt Test.

    PubMed

    Lacks, P B; Newport, K

    1980-08-01

    Compared the usefulness of four scoring approaches to the Bender-Gestalt Test (Hain, Hutt-Briskin, Pauker, and number of rotations) on the same sample of 50 mixed, psychiatric inpatients. Also, the accuracy of scorers of varying levels of experience was compared. Twelve different scorers were used representing three levels of expertise: "expert," "typical," and "novice." For a measure of reliability and two measures of diagnostic discrimination the Hutt-Briskin and Pauker systems were more successful than the Hain system or number of rotations. For each scoring system there were no differences in diagnostic accuracy attributable to level of past experience. It was recommended that the findings on the Pauker system be cross-validated before being used in clinical settings.

  9. Electronic structure Fermi liquid theory of high Tc superconductors: Comparison of predictions with experiments

    NASA Technical Reports Server (NTRS)

    Yu, Jaejun; Freeman, A. J.

    1991-01-01

    Predictions of local density functional (LDF) calculations of the electronic structure and transport properties of high T(sub c) superconductors are presented. As evidenced by the excellent agreement with both photoemission and positron annihilation experiments, a Fermi liquid nature of the 'normal' state of the high T(sub c) superconductors become clear for the metallic phase of these oxides. In addition, LDF predictions on the normal state transport properties are qualitatively in agreement with experiments on single crystals. It is emphasized that the signs of the Hall coefficients for the high T(sub c) superconductors are not consistent with the types of dopants (e.g., electron-doped or hole-doped) but are determined by the topology of the Fermi surfaces obtained from the LDF calculations.

  10. Mixing of a point-source indoor pollutant: Numerical predictions and comparison with experiments

    SciTech Connect

    Lobscheid, C.; Gadgil, A.J.

    2002-01-01

    In most practical estimates of indoor pollutant exposures, it is common to assume that the pollutant is uniformly and instantaneously mixed in the indoor space. It is also commonly known that this assumption is simplistic, particularly for point sources, and for short-term or localized indoor exposures. We report computational fluid dynamics (CFD) predictions of mixing time of a point-pulse release of a pollutant in an unventilated mechanically mixed isothermal room. We aimed to determine the adequacy of the standard RANS two-equation ({kappa}-{var_epsilon}) turbulence model to predict the mixing times under these conditions. The predictions were made for the twelve mixing time experiments performed by Drescher et al. (1995). We paid attention to adequate grid resolution, suppression of numerical diffusion, and careful simulation of the mechanical blowers used in the experiments. We found that the predictions are in good agreement with experimental measurements.

  11. Sample size determination in clinical proteomic profiling experiments using mass spectrometry for class comparison.

    PubMed

    Cairns, David A; Barrett, Jennifer H; Billingham, Lucinda J; Stanley, Anthea J; Xinarianos, George; Field, John K; Johnson, Phillip J; Selby, Peter J; Banks, Rosamonde E

    2009-01-01

    Mass spectrometric profiling approaches such as MALDI-TOF and SELDI-TOF are increasingly being used in disease marker discovery, particularly in the lower molecular weight proteome. However, little consideration has been given to the issue of sample size in experimental design. The aim of this study was to develop a protocol for the use of sample size calculations in proteomic profiling studies using MS. These sample size calculations can be based on a simple linear mixed model which allows the inclusion of estimates of biological and technical variation inherent in the experiment. The use of a pilot experiment to estimate these components of variance is investigated and is shown to work well when compared with larger studies. Examination of data from a number of studies using different sample types and different chromatographic surfaces shows the need for sample- and preparation-specific sample size calculations.

  12. Comparison of Monte Carlo simulations of cytochrome b6f with experiment using Latin hypercube sampling.

    PubMed

    Schumaker, Mark F; Kramer, David M

    2011-09-01

    We have programmed a Monte Carlo simulation of the Q-cycle model of electron transport in cytochrome b(6)f complex, an enzyme in the photosynthetic pathway that converts sunlight into biologically useful forms of chemical energy. Results were compared with published experiments of Kramer and Crofts (Biochim. Biophys. Acta 1183:72-84, 1993). Rates for the simulation were optimized by constructing large numbers of parameter sets using Latin hypercube sampling and selecting those that gave the minimum mean square deviation from experiment. Multiple copies of the simulation program were run in parallel on a Beowulf cluster. We found that Latin hypercube sampling works well as a method for approximately optimizing very noisy objective functions of 15 or 22 variables. Further, the simplified Q-cycle model can reproduce experimental results in the presence or absence of a quinone reductase (Q(i)) site inhibitor without invoking ad hoc side-reactions.

  13. Isentropic Compression for TATB Based HE Samples, Numerical Simulations and Comparison with Experiments

    SciTech Connect

    Lefrancois, A; Vandersall, K; L'Eplattenier, P; Burger, M

    2006-02-06

    Isentropic compression experiments and numerical simulations on TATB based HE were performed respectively at Z accelerator facility from Sandia National Laboratory and at Lawrence Livermore National Laboratory in order to study the isentrope and associated Hugoniot of this HE [1]. 3D configurations have been calculated here to test the new beta version of the electromagnetism package coupled with the dynamics in Ls-Dyna and compared with the ICE Z shot 1967.

  14. Critical transition for the edge shear layer formation: Comparison of model and experiment

    SciTech Connect

    Carreras, B. A.; Garcia, L.; Pedrosa, M. A.; Hidalgo, C.

    2006-12-15

    The experimental results for the emergence of the plasma edge shear flow layer in TJ-II [C. Alehaldre et al.Fusion Technol. 17, 131 (1990)] can be explained using a simple model for a second-order transition based on the sheared flow amplification by Reynolds stress and turbulence suppression by shearing. In the dynamics of the model, the resistive interchange instability is used. This model gives power dependence on density gradients before and after the transition, consistent with experiment.

  15. Direct comparison of elastic incoherent neutron scattering experiments with molecular dynamics simulations of DMPC phase transitions.

    PubMed

    Aoun, Bachir; Pellegrini, Eric; Trapp, Marcus; Natali, Francesca; Cantù, Laura; Brocca, Paola; Gerelli, Yuri; Demé, Bruno; Marek Koza, Michael; Johnson, Mark; Peters, Judith

    2016-04-01

    Neutron scattering techniques have been employed to investigate 1,2-dimyristoyl-sn -glycero-3-phosphocholine (DMPC) membranes in the form of multilamellar vesicles (MLVs) and deposited, stacked multilamellar-bilayers (MLBs), covering transitions from the gel to the liquid phase. Neutron diffraction was used to characterise the samples in terms of transition temperatures, whereas elastic incoherent neutron scattering (EINS) demonstrates that the dynamics on the sub-macromolecular length-scale and pico- to nano-second time-scale are correlated with the structural transitions through a discontinuity in the observed elastic intensities and the derived mean square displacements. Molecular dynamics simulations have been performed in parallel focussing on the length-, time- and temperature-scales of the neutron experiments. They correctly reproduce the structural features of the main gel-liquid phase transition. Particular emphasis is placed on the dynamical amplitudes derived from experiment and simulations. Two methods are used to analyse the experimental data and mean square displacements. They agree within a factor of 2 irrespective of the probed time-scale, i.e. the instrument utilized. Mean square displacements computed from simulations show a comparable level of agreement with the experimental values, albeit, the best match with the two methods varies for the two instruments. Consequently, experiments and simulations together give a consistent picture of the structural and dynamical aspects of the main lipid transition and provide a basis for future, theoretical modelling of dynamics and phase behaviour in membranes. The need for more detailed analytical models is pointed out by the remaining variation of the dynamical amplitudes derived in two different ways from experiments on the one hand and simulations on the other.

  16. Electrowetting with contact line pinning: Computational modeling and comparisons with experiments

    NASA Astrophysics Data System (ADS)

    Walker, Shawn W.; Shapiro, Benjamin; Nochetto, Ricardo H.

    2009-10-01

    This work describes the modeling and simulation of planar electrowetting on dielectric devices that move fluid droplets by modulating surface tension effects. The fluid dynamics are modeled by Hele-Shaw type equations with a focus on including the relevant boundary phenomena. Specifically, we include contact angle saturation and a contact line force threshold model that can account for hysteresis and pinning effects. These extra boundary effects are needed to make reasonable predictions of the correct shape and time scale of liquid motion. Without them the simulations can predict droplet motion that is much faster than in experiments (up to 10-20 times faster). We present a variational method for our model, and a corresponding finite element discretization, which is able to handle surface tension, conservation of mass, and the nonlinear contact line pinning in a straightforward and numerically robust way. In particular, the contact line pinning is captured by a variational inequality. We note that all the parameters in our model are derived from first principles or from independent experiments except one (the parameter Dvisc that accounts for the extra resistive effect of contact angle hysteresis and is difficult to measure directly). We quantitatively compare our simulation to available experimental data for four different cases of droplet motion that include splitting and joining of droplets and find good agreement with experiments.

  17. Comparison of continuous and discontinuous collisional bumpers: Dimensionally scaled impact experiments into single wire meshes

    NASA Technical Reports Server (NTRS)

    Hoerz, Friedrich; Cintala, Mark; See, Thomas; Bernhard, Ronald; Cardenas, Frank; Davidson, William; Haynes, Jerry

    1992-01-01

    An experimental inquiry into the utility of discontinuous bumpers was conducted to investigate the collisional outcomes of impacts into single grid-like targets and to compare the results with more traditional bumper designs that employ continuous sheet stock. We performed some 35 experiments using 6.3 and 3.2 mm diameter spherical soda-lime glass projectiles at low velocities (less than 2.5 km/s) and 13 at velocities between 5 and 6 km/s, using 3.2 mm spheres only. The thrust of the experiments related to the characterization of collisional fragments as a function of target thickness or areal shield mass of both bumper designs. The primary product of these experiments was witness plates that record the resulting population of collisional fragments. Substantial interpretive and predictive insights into bumper performance were obtained. All qualitative observations (on the witness plates) and detailed measurements of displaced masses seem simply and consistently related only to bumper mass available for interaction with the impactor. This renders the grid bumper into the superior shield design. These findings present evidence that discontinuous bumpers are a viable concept for collisional shields, possibly superior to continuous geometries.

  18. An observational comparison of the older and younger bus passenger experience in a developing world city.

    PubMed

    Aceves-González, Carlos; May, Andrew; Cook, Sharon

    2016-06-01

    This study was an unobtrusive observational analysis of 333 older and younger bus passengers in Guadalajara, Mexico. A set of data were collected for each observed passenger, as well as more general observations related to driver behaviour, bus design and bus service characteristics. There were significant differences between older and younger passengers in terms of boarding and alighting times, use of handrails, seat location preferences, passenger stability and coping strategies in order to maintain postural stability. The conditions of travel are conducive to a poor passenger experience for the older passengers in particular. Although the problems may be attributed to bus design and driver behaviour typical of that in developing countries, they are also influenced by the wider transport infrastructure, and a lack of a regulatory regime which places drivers under time pressure and in direct competition with each other. Practitioner Summary: Bus services must cater for all ages of passengers, including the elderly. This unobtrusive observational study investigated the passenger experience in a developing world city. Bus and wider service design were found to compromise the journey experience, with the older users being particularly negatively impacted. Design recommendations are provided.

  19. Quantum state-resolved, bulk gas energetics: Comparison of theory and experiment

    NASA Astrophysics Data System (ADS)

    McCaffery, Anthony J.

    2016-05-01

    Until very recently, the computational model of state-to-state energy transfer in large gas mixtures, introduced by the author and co-workers, has had little experimental data with which to assess the accuracy of its predictions. In a novel experiment, Alghazi et al. [Chem. Phys. 448, 76 (2015)] followed the equilibration of highly vibrationally excited CsH(D) in baths of H2(D2) with simultaneous time- and quantum state-resolution. Modal temperatures of vibration, rotation, and translation for CsH(D) were obtained and presented as a function of pump-probe delay time. Here the data from this study are used as a test of the accuracy of the computational method, and in addition, the consequent changes in bath gas modal temperatures, not obtainable in the experiment, are predicted. Despite large discrepancies between initial CsH(D) vibrational states in the experiment and those available using the computational model, the quality of agreement is sufficient to conclude that the model's predictions constitute at least a very good representation of the overall equilibration that, for some measurements, is very accurate.

  20. Simulation of dense water overflows with an isopycnal model and comparisons with laboratory experiments

    NASA Astrophysics Data System (ADS)

    Decamp, S.; Sommeria, J.

    2003-04-01

    We test the ability of an isopycnal model to simulate dense water overflows on a slope, with appropriate diapycnal entrainement. We use the Miami Isopycnic Coordinate Ocean Model, as complemented by Papadakis, Chassignet and Hallberg (2003) to include the parametrization of the Richardson number dependent entrainment of Turner (1986). As a test case, we compare the model results with a laboratory experiment in dynamical similitude with oceanic conditions. The experiments are performed on the Coriolis rotating table (Grenoble, France) with a gravity current flowing down a slope in a uniformly stratified environment, the density of the incoming fluid being that of the bottom water (see communication by Pavia et al.). The large dimensions of the turn-table allows good similarity with the oceanic scale, so that the experiments reproduce a dense flow over a 122 km wide by 3000 m deep continental slope. After a downward motion with intense turbulent mixing, the current is stabilized into a geostrophically balanced along slope jet. We compare the jet position and velocity to laboratory measurements, as well as mixing of the incoming water mass with the environment.

  1. Comparison of hydrodynamic simulations with two-shockwave drive target experiments

    NASA Astrophysics Data System (ADS)

    Karkhanis, Varad; Ramaprabhu, Praveen; Buttler, William

    2015-11-01

    We consider hydrodynamic continuum simulations to mimic ejecta generation in two-shockwave target experiments, where metallic surface is loaded by two successive shock waves. Time of second shock in simulations is determined to match experimental amplitudes at the arrival of the second shock. The negative Atwood number A --> - 1 of ejecta simulations leads to two successive phase inversions of the interface corresponding to the passage of the shocks from heavy to light media in each instance. Metallic phase of ejecta (solid/liquid) depends on shock loading pressure in the experiment, and we find that hydrodynamic simulations quantify the liquid phase ejecta physics with a fair degree of accuracy, where RM instability is not suppressed by the strength effect. In particular, we find that our results of free surface velocity, maximum ejecta velocity, and maximum ejecta areal density are in excellent agreement with their experimental counterparts, as well as ejecta models. We also comment on the parametric space for hydrodynamic simulations in which they can be used to compare with the target experiments. This work was supported in part by the (U.S.) Department of Energy (DOE) under Contract No. DE-AC52-06NA2-5396.

  2. Comparison of hydrodynamic simulations with two-shockwave drive target experiments

    NASA Astrophysics Data System (ADS)

    Karkhanis, Varad; Ramaprabhu, Praveen; Buttler, William

    2015-11-01

    We consider hydrodynamic continuum simulations to mimic ejecta generation in two-shockwave target experiments, where metallic surface is loaded by two successive shock waves. Time of second shock in simulations is determined to match experimental amplitudes at the arrival of the second shock. The negative Atwood number (A --> - 1) of ejecta simulations leads to two successive phase inversions of the interface corresponding to the passage of the shocks from heavy to light media in each instance. Metallic phase of ejecta (solid/liquid) depends on shock loading pressure in the experiment, and we find that hydrodynamic simulations quantify the liquid phase ejecta physics with a fair degree of accuracy, where RM instability is not suppressed by the strength effect. In particular, we find that our results of free surface velocity, maximum ejecta velocity, and maximum ejecta areal density are in excellent agreement with their experimental counterparts, as well as ejecta models. We also comment on the parametric space for hydrodynamic simulations in which they can be used to compare with the target experiments.

  3. Computer-assisted comparison of analysis and test results in transportation experiments

    SciTech Connect

    Knight, R.D.; Ammerman, D.J.; Koski, J.A.

    1998-05-10

    As a part of its ongoing research efforts, Sandia National Laboratories` Transportation Surety Center investigates the integrity of various containment methods for hazardous materials transport, subject to anomalous structural and thermal events such as free-fall impacts, collisions, and fires in both open and confined areas. Since it is not possible to conduct field experiments for every set of possible conditions under which an actual transportation accident might occur, accurate modeling methods must be developed which will yield reliable simulations of the effects of accident events under various scenarios. This requires computer software which is capable of assimilating and processing data from experiments performed as benchmarks, as well as data obtained from numerical models that simulate the experiment. Software tools which can present all of these results in a meaningful and useful way to the analyst are a critical aspect of this process. The purpose of this work is to provide software resources on a long term basis, and to ensure that the data visualization capabilities of the Center keep pace with advancing technology. This will provide leverage for its modeling and analysis abilities in a rapidly evolving hardware/software environment.

  4. Numerical simulations of the flow with the prescribed displacement of the airfoil and comparison with experiment

    NASA Astrophysics Data System (ADS)

    Řidký, V.; Šidlof, P.; Vlček, V.

    2013-04-01

    The work is devoted to comparing measured data with the results of numerical simulations. As mathematical model was used mathematical model whitout turbulence for incompressible flow In the experiment was observed the behavior of designed NACA0015 airfoil in airflow. For the numerical solution was used OpenFOAM computational package, this is open-source software based on finite volume method. In the numerical solution is prescribed displacement of the airfoil, which corresponds to the experiment. The velocity at a point close to the airfoil surface is compared with the experimental data obtained from interferographic measurements of the velocity field. Numerical solution is computed on a 3D mesh composed of about 1 million ortogonal hexahedron elements. The time step is limited by the Courant number. Parallel computations are run on supercomputers of the CIV at Technical University in Prague (HAL and FOX) and on a computer cluster of the Faculty of Mechatronics of Liberec (HYDRA). Run time is fixed at five periods, the results from the fifth periods and average value for all periods are then be compared with experiment.

  5. Comparison of fission product release predictions using PARFUME with results from the AGR-1 irradiation experiment

    SciTech Connect

    Blaise Collin

    2014-09-01

    This report documents comparisons between post-irradiation examination measurements and model predictions of silver (Ag), cesium (Cs), and strontium (Sr) release from selected tristructural isotropic (TRISO) fuel particles and compacts during the first irradiation test of the Advanced Gas Reactor program that occurred from December 2006 to November 2009 in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). The modeling was performed using the particle fuel model computer code PARFUME (PARticle FUel ModEl) developed at INL. PARFUME is an advanced gas-cooled reactor fuel performance modeling and analysis code (Miller 2009). It has been developed as an integrated mechanistic code that evaluates the thermal, mechanical, and physico-chemical behavior of fuel particles during irradiation to determine the failure probability of a population of fuel particles given the particle-to-particle statistical variations in physical dimensions and material properties that arise from the fuel fabrication process, accounting for all viable mechanisms that can lead to particle failure. The code also determines the diffusion of fission products from the fuel through the particle coating layers, and through the fuel matrix to the coolant boundary. The subsequent release of fission products is calculated at the compact level (release of fission products from the compact) but it can be assessed at the particle level by adjusting the diffusivity in the fuel matrix to very high values. Furthermore, the diffusivity of each layer can be individually set to a high value (typically 10-6 m2/s) to simulate a failed layer with no capability of fission product retention. In this study, the comparison to PIE focused on fission product release and because of the lack of failure in the irradiation, the probability of particle failure was not calculated. During the AGR-1 irradiation campaign, the fuel kernel produced and released fission products, which migrated through the successive

  6. Structural Ensembles of Intrinsically Disordered Proteins Depend Strongly on Force Field: A Comparison to Experiment.

    PubMed

    Rauscher, Sarah; Gapsys, Vytautas; Gajda, Michal J; Zweckstetter, Markus; de Groot, Bert L; Grubmüller, Helmut

    2015-11-10

    Intrinsically disordered proteins (IDPs) are notoriously challenging to study both experimentally and computationally. The structure of IDPs cannot be described by a single conformation but must instead be described as an ensemble of interconverting conformations. Atomistic simulations are increasingly used to obtain such IDP conformational ensembles. Here, we have compared the IDP ensembles generated by eight all-atom empirical force fields against primary small-angle X-ray scattering (SAXS) and NMR data. Ensembles obtained with different force fields exhibit marked differences in chain dimensions, hydrogen bonding, and secondary structure content. These differences are unexpectedly large: changing the force field is found to have a stronger effect on secondary structure content than changing the entire peptide sequence. The CHARMM 22* ensemble performs best in this force field comparison: it has the lowest error in chemical shifts and J-couplings and agrees well with the SAXS data. A high population of left-handed α-helix is present in the CHARMM 36 ensemble, which is inconsistent with measured scalar couplings. To eliminate inadequate sampling as a reason for differences between force fields, extensive simulations were carried out (0.964 ms in total); the remaining small sampling uncertainty is shown to be much smaller than the observed differences. Our findings highlight how IDPs, with their rugged energy landscapes, are highly sensitive test systems that are capable of revealing force field deficiencies and, therefore, contributing to force field development.

  7. Optimization design of submerged propeller in oxidation ditch by computational fluid dynamics and comparison with experiments.

    PubMed

    Zhang, Yuquan; Zheng, Yuan; Fernandez-Rodriguez, E; Yang, Chunxia; Zhu, Yantao; Liu, Huiwen; Jiang, Hao

    The operating condition of a submerged propeller has a significant impact on flow field and energy consumption of the oxidation ditch. An experimentally validated numerical model, based on the computational fluid dynamics (CFD) tool, is presented to optimize the operating condition by considering two important factors: flow field and energy consumption. Performance demonstration and comparison of different operating conditions were carried out in a Carrousel oxidation ditch at the Yingtang wastewater treatment plants in Anhui Province, China. By adjusting the position and rotating speed together with the number of submerged propellers, problems of sludge deposit and the low velocity in the bend could be solved in a most cost-effective way. The simulated results were acceptable compared with the experimental data and the following results were obtained. The CFD model characterized flow pattern and energy consumption in the full-scale oxidation ditch. The predicted flow field values were within -1.28 ± 7.14% difference from the measured values. By determining three sets of propellers under the rotating speed of 6.50 rad/s with one located 5 m from the first curved wall, after numerical simulation and actual measurement, not only the least power density but also the requirement of the flow pattern could be realized.

  8. Sound propagation in and radiation from acoustically lined flow ducts: A comparison of experiment and theory

    NASA Technical Reports Server (NTRS)

    Plumblee, H. E., Jr.; Dean, P. D.; Wynne, G. A.; Burrin, R. H.

    1973-01-01

    The results of an experimental and theoretical study of many of the fundamental details of sound propagation in hard wall and soft wall annular flow ducts are reported. The theory of sound propagation along such ducts and the theory for determining the complex radiation impedance of higher order modes of an annulus are outlined, and methods for generating acoustic duct modes are developed. The results of a detailed measurement program on propagation in rigid wall annular ducts with and without airflow through the duct are presented. Techniques are described for measuring cut-on frequencies, modal phase speed, and radial and annular mode shapes. The effects of flow velocity on cut-on frequencies and phase speed are measured. Comparisons are made with theoretical predictions for all of the effects studies. The two microphone method of impedance is used to measure the effects of flow on acoustic liners. A numerical study of sound propagation in annular ducts with one or both walls acoustically lined is presented.

  9. EX-PRESS glaucoma filtration device: Review of clinical experience and comparison with trabeculectomy.

    PubMed

    Shaarawy, Tarek; Goldberg, Ivan; Fechtner, Robert

    2015-01-01

    Glaucoma filtration surgery is performed to reduce intraocular pressure (IOP) in patients for whom maximal tolerable pharmacologic IOP-lowering therapy and/or laser surgery fail to lower IOP sufficiently and/or fail to prevent optic nerve damage or visual field deterioration. For decades, the most widely utilized procedure for glaucoma filtration surgery has been trabeculectomy. Although this approach reliably provides long-term IOP reduction in many patients, the postoperative complication rate is high. This has driven the development of alternative approaches to reduce IOP surgically. The EX-PRESS glaucoma filtration device was developed to mimic IOP control by trabeculectomy and to have a better safety profile. This non-valved, medical-grade stainless steel device diverts aqueous humor from the anterior chamber to an intrascleral space. Despite the widespread use of the EX-PRESS device, only a few studies compare its efficacy and safety with that of trabeculectomy. We analyze available data regarding the safety and efficacy of the EX-PRESS device, particularly in comparison with trabeculectomy.

  10. Comparison of analysis and experiment for dynamics of low-contact-ratio spur gears

    NASA Technical Reports Server (NTRS)

    Oswald, Fred B.; Rebbechi, Brian; Zakrajsek, James J.; Townsend, Dennis P.; Lin, Hsiang Hsi

    1991-01-01

    Low-contact-ratio spur gears were tested in NASA gear-noise-rig to study gear dynamics including dynamic load, tooth bending stress, vibration, and noise. The experimental results were compared with a NASA gear dynamics code to validate the code as a design tool for predicting transmission vibration and noise. Analytical predictions and experimental data for gear-tooth dynamic loads and tooth-root bending stress were compared at 28 operating conditions. Strain gage data were used to compute the normal load between meshing teeth and the bending stress at the tooth root for direct comparison with the analysis. The computed and measured waveforms for dynamic load and stress were compared for several test conditions. These are very similar in shape, which means the analysis successfully simulates the physical behavior of the test gears. The predicted peak value of the dynamic load agrees with the measurement results within an average error of 4.9 percent except at low-torque, high-speed conditions. Predictions of peak dynamic root stress are generally within 10 to 15 percent of the measured values.

  11. Molecular dynamic simulations of N2-broadened methane line shapes and comparison with experiments

    NASA Astrophysics Data System (ADS)

    Le, Tuong; Doménech, José-Luis; Lepère, Muriel; Tran, Ha

    2017-03-01

    Absorption spectra of methane transitions broadened by nitrogen have been calculated for the first time using classical molecular dynamic simulations. For that, the time evolution of the auto-correlation function of the dipole moment vector, assumed along a C-H axis, was computed using an accurate site-site intermolecular potential for CH4-N2. Quaternion coordinates were used to treat the rotation of the molecules. A requantization procedure was applied to the classical rotation and spectra were then derived as the Fourier-Laplace transform of the auto-correlation function. These computed spectra were compared with experimental ones recorded with a tunable diode laser and a difference-frequency laser spectrometer. Specifically, nine isolated methane lines broadened by nitrogen, belonging to various vibrational bands and having rotational quantum numbers J from 0 to 9, were measured at room temperature and at several pressures from 20 to 945 mbar. Comparisons between measured and calculated spectra were made through their fits using the Voigt profile. The results show that ab initio calculated spectra reproduce with very high fidelity non-Voigt effects on the measurements and that classical molecular dynamic simulations can be used to predict spectral shapes of isolated lines of methane perturbed by nitrogen.

  12. A Comparison of Seismicity Characteristics and Fault Structure Between Stick-Slip Experiments and Nature

    NASA Astrophysics Data System (ADS)

    Goebel, T. H. W.; Sammis, C. G.; Becker, T. W.; Dresen, G.; Schorlemmer, D.

    2015-08-01

    Fault zones contain structural complexity on all scales. This complexity influences fault mechanics including the dynamics of large earthquakes as well as the spatial and temporal distribution of small seismic events. Incomplete earthquake records, unknown stresses, and unresolved fault structures within the crust complicate a quantitative assessment of the parameters that control factors affecting seismicity. To better understand the relationship between fault structure and seismicity, we examined dynamic faulting under controlled conditions in the laboratory by creating saw-cut-guided natural fractures in cylindrical granite samples. The resulting rough surfaces were triaxially loaded to produce a sequence of stick-slip events. During these experiments, we monitored stress, strain, and seismic activity. After the experiments, fault structures were imaged in thin sections and using computer tomography. The laboratory fault zones showed many structural characteristics observed in upper crustal faults, including zones of localized slip embedded in a layer of fault gouge. Laboratory faults also exhibited a several millimeter wide damage zone with decreasing micro-crack density at larger distances from the fault axis. In addition to the structural similarities, we also observed many similarities between our observed distribution of acoustic emissions (AEs) and natural seismicity. The AEs followed the Gutenberg-Richter and Omori-Utsu relationships commonly used to describe natural seismicity. Moreover, we observed a connection between along-strike fault heterogeneity and variations of the Gutenberg-Richter b value. As suggested by natural seismicity studies, areas of low b value marked the nucleation points of large slip events and were located at large asperities within the fault zone that were revealed by post-experimental tomography scans. Our results emphasize the importance of stick-slip experiments for the study of fault mechanics. The direct correlation of

  13. Comparisons of laboratory bioassays and a whole-lake experiment: Rotifer responses to experimental acidification

    SciTech Connect

    Gonzalez, M.J.; Frost, T.M. )

    1994-02-01

    The authors test whether data from laboratory bioassays can be used to predict zooplankton responses during a whole-lake experiment using two rotifers, Keratella cochlearis and Keratella taurocephala. The acidification experiment was conducted in Little Rock Lake, Wisconsin, USA, which was divided into a reference basin maintained at a natural pH near 6.1 and a treatment basin which was acidified in 2-yr stages to pH values of 5.6, 5.2, and 4.7. Laboratory assays examined the effect of pH on reproduction under varied food conditions and survivorship without food. In the lake, the two rotifers showed strong and opposite responses to acidification: K. cochlearis decreased in abundance while K. taurocephala increased. In the laboratory bioassays, neither species was sensitive to pH when food conditions yielded high reproductive rates. When food was limited, K. cochlearis exhibited lower survivorship and a trend towards lower reproductive rates at lower pH. With limited food, K. taurocephala survivorship was either unaffected by pH or higher at high pH and its reproduction was slightly higher at intermediate pH. In situ experiments revealed that food conditions in the treatment basin lowered reproduction by K. cochlearis, indicating that a combined effect of food and pH caused its population decline. Neither food nor pH could explain the increase in K. taurocephala, which appeared to be linked to a reduction in its predators at lower pH. Overall, the analyses revealed substantial discrepancies between laboratory bioassays and in-lake responses. This was particularly the case for K. taurocephala, for which assays predicted no changes or a decline in abundance rather than the marked increase that actually occurred. The results suggest that caution should be used in extending results from laboratory assays to natural ecosystems.

  14. Quasi-cylindrical theory of wing-body interference at supersonic speeds and comparison with experiment

    NASA Technical Reports Server (NTRS)

    Nielsen, Jack N

    1955-01-01

    A theoretical method is presented for calculating the flow field about wing-body combinations employing bodies deviating only slightly in shape from a circular cylinder. The method is applied to the calculation of the pressure field acting between a circular cylindrical body and a rectangular wing. The case of zero body angle of attack and variable wing incidence is considered as well as the case of zero wing incidence and variable body angle of attack. An experiment was performed especially for the purpose of checking the calculative examples.

  15. [Comparison of the Results of Satellite Studies of "Mars-500" Experiment Participans in Syktyvkar and Almaty].

    PubMed

    Solonin, Iu G; Markov, A L; Bojko, E R; Akanov, A A; Yeshmanova, A K

    2015-01-01

    Participants of "Mars-500" experiment living in Syktyvkar (northerners) and Almaty (southerners) were studied throughout the year in various seasons. Latitude-caused differences of vegetative index values (RMSSD and pNN50) between groups were found in summer. Northerners were found to have significant seasonal shifts in thermoregulation parameters and RMSSD and pNN50 values. Southerners showed no seasonal changes in abovementioned indices. Participants from both groups were shown to have deviations of several physiological parameters from moderate latitude norms. Many participants from both groups demonstrated stress in adaptation mechanisms. Orthostatic tests performed in both groups revealed deficiencies in regulation of blood circulation.

  16. HAMLET -Matroshka IIA and IIB experiments aboard the ISS: comparison of organ doses

    NASA Astrophysics Data System (ADS)

    Kato, Zoltan; Reitz, Guenther; Berger, Thomas; Bilski, Pawel; Hajek, Michael; Sihver, Lembit; Palfalvi, Jozsef K.; Hager, Luke; Burmeister, Soenke

    The Matroshka experiments and the related FP7 HAMLET project aimed to study the dose burden of the cosmic rays in the organs of the crew working inside and outside the ISS. Two of the experiments will be discussed. They were performed in two different locations inside the ISS: during the Matroshka 2A (in 2006) the phantom was stored in the Russian Docking Module (Pirs), while during the Matroshka 2B (in 2007-08) it was inside the Russian Service Module (Zvezda). Both experiments were performed in the decreasing phase of the solar cycle. Solid state nuclear track detectors (SSNTD) were applied to investigate the dose contribution of the high LET radiation above ˜10 keV/µm. Two configurations of SSNTDs stacks were constructed: one for the exposure in the so called organ dose boxes (in the lung and kidney), another one for the skin dose measurements, embedded in the nomex poncho of the Phantom. In addition a reference package was placed outside the phantom. After exposure the detectors were transferred to the Earth for data evaluation. Short and long etching procedures were applied to distinguish the high and low LET particles, respectively. The particle tracks were evaluated by a semi automated image analyzer. Addi-tionally manual track parameter measurements were performed on very long tracks. As the result of measurements the LET spectra were deduced. Based on these spectra, the absorbed dose, the dose equivalent and the mean quality factor were calculated. The configuration of the stacks, the methods of the calibration and evaluation and finally the results will be presented and compared. The multiple etching and the combined evaluation method allowed to determine the fraction of the dose originated from HZE particles (Z>2 and range > major axis). Further on, data eval-uation was performed to separate the secondary particles (target fragments) from the primary particles. Although the number of high LET particles above a ˜80 keV/µm was found to be higher during

  17. Plume formation and lithosphere erosion - A comparison of laboratory and numerical experiments

    NASA Technical Reports Server (NTRS)

    Olson, Peter; Schubert, Gerald; Anderson, Charles; Goldman, Peggy

    1988-01-01

    The mechanics of thermal plume formation and intrusion into the lithosphere are investigated using a combination of laboratory and numerical simulations. The sequence of events leading to lithospheric thinning and uplift by thermal plumes is established, and some numerical estimates of the time scales for each stage in this process are derived that are applicable to the mantle. It is demonstrated that the two-dimensional finite element computations successfully reproduce the qualitative features seen in the experiments, with a quantitative discrepancy of typically 30 percent or less. The results of some calculations on plume formation and intrusion into model lithospheres with a variety of rheologies are presented.

  18. A comparison of memory for homicide, non-homicidal violence, and positive life experiences.

    PubMed

    Woodworth, Michael; Porter, Stephen; Ten Brinke, Leanne; Doucette, Naomi L; Peace, Kristine; Campbell, Mary Ann

    2009-01-01

    Defendants commonly claim amnesia for their criminal actions especially in cases involving extreme violence. While some claims are malingered or result from physiological factors, other cases may represent genuine partial or complete amnesia resulting from the psychological distress and/or extreme emotion associated with the perpetration of the crime. Fifty Canadian homicide offenders described their memories of their homicide, a non-homicide violent offense, and their most positive adulthood life experience. Self-reported and objective measures of memories for these events revealed that homicides were recalled with the greatest level of detail and sensory information. Although dissociative tendencies were associated with a self-reported memory loss, objective measures of memory quality did not reflect this perceived impairment, suggesting a failure of meta-memory. Recollections of positive life events were superior to those of non-homicidal violence, possibly due to greater impact and meaning attached to such experiences. Findings suggest that memory for homicide typically is enhanced by the powerful emotion associated with its perpetration.

  19. Evaluation of the Monte Carlo method (KTMAN-2) in fluoroscopic dosimetry and comparison with experiment

    NASA Astrophysics Data System (ADS)

    Kim, Minho; Lee, Hyounggun; Kim, Hyosim; Park, Hongmin; Lee, Wonho; Park, Sungho

    2014-03-01

    This study evaluated the Monte Carlo method for determining the dose calculation in fluoroscopy by using a realistic human phantom. The dose was calculated by using Monte Carlo N-particle extended (MCNPX) in simulations and was measured by using Korean Typical Man-2 (KTMAN-2) phantom in the experiments. MCNPX is a widely-used simulation tool based on the Monte-Carlo method and uses random sampling. KTMAN-2 is a virtual phantom written in MCNPX language and is based on the typical Korean man. This study was divided into two parts: simulations and experiments. In the former, the spectrum generation program (SRS-78) was used to obtain the output energy spectrum for fluoroscopy; then, each dose to the target organ was calculated using KTMAN-2 with MCNPX. In the latter part, the output of the fluoroscope was calibrated first and TLDs (Thermoluminescent dosimeter) were inserted in the ART (Alderson Radiation Therapy) phantom at the same places as in the simulation. Thus, the phantom was exposed to radiation, and the simulated and the experimental doses were compared. In order to change the simulation unit to the dose unit, we set the normalization factor (NF) for unit conversion. Comparing the simulated with the experimental results, we found most of the values to be similar, which proved the effectiveness of the Monte Carlo method in fluoroscopic dose evaluation. The equipment used in this study included a TLD, a TLD reader, an ART phantom, an ionization chamber and a fluoroscope.

  20. Profile stiffness measurements in the Helically Symmetric experiment and comparison to nonlinear gyrokinetic calculations

    SciTech Connect

    Weir, G. M.; Faber, B. J.; Likin, K. M.; Talmadge, J. N.; Anderson, D. T.; Anderson, F. S. B.

    2015-05-15

    Stiffness measurements are presented in the quasi-helically symmetric experiment (HSX), in which the neoclassical transport is comparable to that in a tokamak and turbulent transport dominates throughout the plasma. Electron cyclotron emission is used to measure the local electron temperature response to modulated electron cyclotron resonant heating. The amplitude and phase of the heat wave through the steep electron temperature gradient (ETG) region of the plasma are used to determine a transient electron thermal diffusivity that is close to the steady-state diffusivity. The low stiffness in the region between 0.2 ≤ r/a ≤ 0.4 agrees with the scaling of the steady-state heat flux with temperature gradient in this region. These experimental results are compared to gyrokinetic calculations in a flux-tube geometry using the gyrokinetic electromagnetic numerical experiment code with two kinetic species. Linear simulations show that the ETG mode may be experimentally relevant within r/a ≤ 0.2, while the Trapped Electron Mode (TEM) is the dominant long-wavelength microturbulence instability across most of the plasma. The TEM is primarily driven by the density gradient. Non-linear calculations of the saturated heat flux driven by the TEM and ETG bracket the experimental heat flux.

  1. Calculation of Oxygen Fugacity in High Pressure Metal-Silicate Experiments and Comparison to Standard Approaches

    NASA Technical Reports Server (NTRS)

    Righter, K.; Ghiorso, M.

    2009-01-01

    Calculation of oxygen fugacity in high pressure and temperature experiments in metal-silicate systems is usually approximated by the ratio of Fe in the metal and FeO in the silicate melt: (Delta)IW=2*log(X(sub Fe)/X(sub FeO)), where IW is the iron-wustite reference oxygen buffer. Although this is a quick and easy calculation to make, it has been applied to a huge variety of metallic (Fe- Ni-S-C-O-Si systems) and silicate liquids (SiO2, Al2O3, TiO2, FeO, MgO, CaO, Na2O, K2O systems). This approach has surely led to values that have little meaning, yet are applied with great confidence, for example, to a terrestrial mantle at "IW-2". Although fO2 can be circumvented in some cases by consideration of Fe-M distribution coefficient, these do not eliminate the effects of alloy or silicate liquid compositional variation, or the specific chemical effects of S in the silicate liquid, for example. In order to address the issue of what the actual value of fO2 is in any given experiment, we have calculated fO2 from the equilibria 2Fe (metal) + SiO2 (liq) + O2 = Fe2SiO4 (liq).

  2. Sputtering and redeposition of ion irradiated Au nanoparticle arrays: direct comparison of simulations to experiments

    NASA Astrophysics Data System (ADS)

    Holland-Moritz, Henry; Ilinov, Andrey; Djurabekova, Flyura; Nordlund, Kai; Ronning, Carsten

    2017-01-01

    Ion beam processing of surfaces is well known to lead to sputtering, which conventionally is associated only with erosion of atoms from the material. We show here, by combination of experiments and a newly developed Monte Carlo algorithm, that in the case of nanoparticles in a regular two-dimensional array on surfaces, the redeposition of sputtered atoms may play a significant role on the system development. The simulations are directly compared to in situ experiments obtained using a dual focused Ga+ ion beam system and high resolution scanning electron microscopy, and explain the size evolution by a combination of sputtering and redeposition of sputtered material on neighboring particles. The effect is found to be dependent on the size of the nanoparticles: if the nanoparticle size is comparable to the ion range, the reposition is negligible. For larger nanoparticles the redeposition becomes significant and is able to compensate up to 20% of the sputtered material, effectively reducing the process of sputtering. The redeposition may even lead to significant growth: this was seen for the nanoparticles with the sizes much smaller than the ion range. Furthermore, the algorithm shows that significant redeposition is possible when the large size neighboring nanoparticles are present.

  3. Comparison of Computational Results with a Low-g, Nitrogen Slosh and Boiling Experiment

    NASA Technical Reports Server (NTRS)

    Stewart, Mark E.; Moder, Jeffrey P.

    2015-01-01

    This paper compares a fluid/thermal simulation, in Fluent, with a low-g, nitrogen slosh and boiling experiment. In 2010, the French Space Agency, CNES, performed cryogenic nitrogen experiments in a low-g aircraft campaign. From one parabolic flight, a low-g interval was simulated that focuses on low-g motion of nitrogen liquid and vapor with significant condensation, evaporation, and boiling. The computational results are compared with high-speed video, pressure data, heat transfer, and temperature data from sensors on the axis of the cylindrically shaped tank. These experimental and computational results compare favorably. The initial temperature stratification is in good agreement, and the two-phase fluid motion is qualitatively captured. Temperature data is matched except that the temperature sensors are unable to capture fast temperature transients when the sensors move from wet to dry (liquid to vapor) operation. Pressure evolution is approximately captured, but condensation and evaporation rate modeling and prediction need further theoretical analysis.

  4. Magnesium: Comparison of density functional theory calculations with electron and x-ray diffraction experiments

    NASA Astrophysics Data System (ADS)

    Friis, J.; Madsen, G. K. H.; Larsen, F. K.; Jiang, B.; Marthinsen, K.; Holmestad, R.

    2003-12-01

    Accurate experimental structure factors for Mg have been measured and compared with density functional theory (DFT) to test some commonly used functionals and self-interaction correction (SIC) schemes. Low order structure factors, free of extinction and on absolute scale, were measured accurately by quantitative convergent beam electron diffraction. In addition, a complete set of structure factors up to sin θ/λ=1.6 Å-1 was measured by x-ray diffraction at 10 K. The DFT calculations were performed using the full potential linearized augmented plane wave method. It was found that the agreement with experiment increases when going from the local density approximation (LDA) to the generalized gradient approximation (GGA) of Perdew, Burke, and Ernzerhofer and further to the GGA of Engel and Vosko. Applying the SIC of Perdew and Zunger to the core states for LDA does not improve the agreement with theory, while applying the SIC of Lundin and Eriksson results in a significantly improved agreement. This implies that the main source of error in the LDA functional comes from the description of the core densities. Using the functional which agrees best with experiment, a non-nuclear maximum is established in the calculated electron density of beryllium but not of magnesium.

  5. Comparison of ``integrating'' and ``tracking'' modes of operation in the Qweak experiment

    NASA Astrophysics Data System (ADS)

    Mahurin, Rob

    2012-10-01

    The Qweak experiment the first direct measurement of the proton's weak charge QW^p, has recently completed data collection at Jefferson Lab. Polarized, 1.165 GeV electrons were scattered from protons and focused onto an array of large (2,x0.18,) fused-silica Cherenkov detectors. We have proposed to measure the parity-violating asymmetry associated with QW^p to a precision of 5 ppb. To meet this statistical requirement, the bulk of the data were collected using ``integrating'' electronics (with typical event rates ˜800,Hz per detector). However, the observed asymmetry also depends on the distribution of momentum transfer Q^2 accepted by the experiment. Measurements of Q^2 were made by inserting wire chamber detectors --- but only with the beam current reduced by three to six orders of magnitude. For these ``tracking'' measurements, the main detectors were connected to electronics able to resolve single events. As a bridge between integrating and tracking modes, a small (1,mx1,m) Cherenkov detector on a motion stage had freedom to scan over one of the large Cherenkov detectors; the small size permitted use of the same electronics at all beam currents. In this talk I will discuss the consistency of results from these various modes of operation.

  6. Sedimentation equilibria in polydisperse ferrofluids: critical comparisons between experiment, theory, and computer simulation.

    PubMed

    Elfimova, Ekaterina A; Ivanov, Alexey O; Lakhtina, Ekaterina V; Pshenichnikov, Alexander F; Camp, Philip J

    2016-05-14

    The sedimentation equilibrium of dipolar particles in a ferrofluid is studied using experiment, theory, and computer simulation. A theory of the particle-concentration profile in a dipolar hard-sphere fluid is developed, based on the local-density approximation and accurate expressions from a recently introduced logarithmic free energy approach. The theory is tested critically against Monte Carlo simulation results for monodisperse and bidisperse dipolar hard-sphere fluids in homogeneous gravitational fields. In the monodisperse case, the theory is very accurate over broad ranges of gravitational field strength, volume fraction, and dipolar coupling constant. In the bidisperse case, with realistic dipolar coupling constants and compositions, the theory is excellent at low volume fraction, but is slightly inaccurate at high volume fraction in that it does not capture a maximum in the small-particle concentration profile seen in simulations. Possible reasons for this are put forward. Experimental measurements of the magnetic-susceptibility profile in a real ferrofluid are then analysed using the theory. The concentration profile is linked to the susceptibility profile using the second-order modified mean-field theory. It is shown that the experimental results are not consistent with the sample being monodisperse. By introducing polydispersity in the simplest possible way, namely by assuming the system is a binary mixture, almost perfect agreement between theory and experiment is achieved.

  7. Numerical Calculations of 3-D High-Lift Flows and Comparison with Experiment

    NASA Technical Reports Server (NTRS)

    Compton, William B, III

    2015-01-01

    Solutions were obtained with the Navier-Stokes CFD code TLNS3D to predict the flow about the NASA Trapezoidal Wing, a high-lift wing composed of three elements: the main-wing element, a deployed leading-edge slat, and a deployed trailing-edge flap. Turbulence was modeled by the Spalart-Allmaras one-equation turbulence model. One case with massive separation was repeated using Menter's two-equation SST (Menter's Shear Stress Transport) k-omega turbulence model in an attempt to improve the agreement with experiment. The investigation was conducted at a free stream Mach number of 0.2, and at angles of attack ranging from 10.004 degrees to 34.858 degrees. The Reynolds number based on the mean aerodynamic chord of the wing was 4.3 x 10 (sup 6). Compared to experiment, the numerical procedure predicted the surface pressures very well at angles of attack in the linear range of the lift. However, computed maximum lift was 5% low. Drag was mainly under predicted. The procedure correctly predicted several well-known trends and features of high-lift flows, such as off-body separation. The two turbulence models yielded significantly different solutions for the repeated case.

  8. Comparison of Raman Scattering Measurements and Modeling in NIF Ignition Experiments

    SciTech Connect

    Strozzi, D J; Hinkel, D E; Williams, E A; Town, R J; Michel, P A; Divol, L; Berger, R L; Moody, J D

    2011-11-04

    Recent NIF indirect-drive experiments have shown significant Raman scattering from the inner beams. NIF data has motivated improvements to rad-hydro modeling, leading to the 'high flux model' [M. D. Rosen et al., HEDP 7, 180 (2011)]. Cross-beam energy transfer [P. A. Michel et al., Phys. Plasmas 17, 056305 (2010] in the laser entrance hole is an important tool for achieving round implosions, and is uniformly distributed across the laser spot in rad-hydro simulations (but not necessarily in experiments). We find the Raman linear gain spectra computed with these plasma conditions agree well in time-dependent peak wavelength with the measured data, especially when overlapping laser-beam intensities are used. More detailed, spatially non-uniform modeling of the cross-beam transfer has been performed. The resulting gains better follow the time history of the measured backscatter. We shall present the impact of spatially non-uniform energy transfer on SRS gain. This metric is valid when amplification is in a linear regime, and so we shall also present an assessment of whether electron trapping in Langmuir waves can play a role in these shots.

  9. Comparison of the calorimetric and kinematic methods of neutrino energy reconstruction in disappearance experiments

    DOE PAGES

    Ankowski, Artur M.; Benhar, Omar; Coloma, Pilar; ...

    2015-10-22

    To be able to achieve their physics goals, future neutrino-oscillation experiments will need to reconstruct the neutrino energy with very high accuracy. In this work, we analyze how the energy reconstruction may be affected by realistic detection capabilities, such as energy resolutions, efficiencies, and thresholds. This allows us to estimate how well the detector performance needs to be determined a priori in order to avoid a sizable bias in the measurement of the relevant oscillation parameters. We compare the kinematic and calorimetric methods of energy reconstruction in the context of two νμ → νμ disappearance experiments operating in different energymore » regimes. For the calorimetric reconstruction method, we find that the detector performance has to be estimated with an O(10%) accuracy to avoid a significant bias in the extracted oscillation parameters. Thus, in the case of kinematic energy reconstruction, we observe that the results exhibit less sensitivity to an overestimation of the detector capabilities.« less

  10. Comparison of the calorimetric and kinematic methods of neutrino energy reconstruction in disappearance experiments

    SciTech Connect

    Ankowski, Artur M.; Benhar, Omar; Coloma, Pilar; Huber, Patrick; Jen, Chun -Min; Mariani, Camillo; Meloni, Davide; Vagnoni, Erica

    2015-10-22

    To be able to achieve their physics goals, future neutrino-oscillation experiments will need to reconstruct the neutrino energy with very high accuracy. In this work, we analyze how the energy reconstruction may be affected by realistic detection capabilities, such as energy resolutions, efficiencies, and thresholds. This allows us to estimate how well the detector performance needs to be determined a priori in order to avoid a sizable bias in the measurement of the relevant oscillation parameters. We compare the kinematic and calorimetric methods of energy reconstruction in the context of two νμ → νμ disappearance experiments operating in different energy regimes. For the calorimetric reconstruction method, we find that the detector performance has to be estimated with an O(10%) accuracy to avoid a significant bias in the extracted oscillation parameters. Thus, in the case of kinematic energy reconstruction, we observe that the results exhibit less sensitivity to an overestimation of the detector capabilities.

  11. Plume formation and lithosphere erosion: A comparison of laboratory and numerical experiments

    SciTech Connect

    Olson, P.; Schubert, G.; Anderson, C.; Goldman, P.

    1988-12-10

    The mechanics of thermal plume formation and intrusion into the lithosphere are investigated using a combination of laboratory experiments and numerical simulations. In the experiments a deep layer of strongly temperature-dependent viscous sucrose solution is heated from below and cooled from above to produce high-viscosity surface and low-viscosity basal thermal boundary layers. Plumes develop from instabilities in the hot boundary layer, ascend, and partially intrude into the cold layer (lid). A set of two-dimensional finite element calculations are made using the experimental geometry, fluid properties, and boundary and initial conditions. Satisfactory agreement is obtained for the number and shape of plumes and the time variation of surface heat flux, basal temperature, and, to a lesser extent, lid thickness. The major discrepancy is the onset time for instability, which is typically 30% late in the calculations. Numerical simulations of mantle plume-lithosphere interaction with subsolidus creep rheology show that thermal plumes do not effectively intrude and erode the lithosphere if upper mantle viscosity is a function of temperature only, unless the activation energy is anomalously low, 50 kJ mol/sup -1/ or less. However, plumes can significantly erode the lithosphere on time scales of 10--20 m.y. if a low-viscosity asthenospheric channel, due to pressure dependence of viscosity, is present. copyright American Geophysical Union 1988

  12. Local experience in cervical cancer imaging: Comparison in tumour assessment between TRUS and MRI

    PubMed Central

    Ordeanu, Claudia; Pop, Diana Cristina; Badea, Radu; Csutak, Csaba; Todor, Nicolae; Ordeanu, Calin; Kerekes, Reka; Coza, Ovidiu; Nagy, Viorica; Achimas-Cadariu, Patriciu; Irimie, Alexandru

    2015-01-01

    Objective The aim of study was to analyze the accuracy of TRUS (transrectal ultrasound) vs. MRI (magnetic resonance imaging) and clinical gynecological examination estimation in the evaluation of tumor dimensions. Methods The patients inclusion criterion included primarily pathologically squamous cell carcinoma, but excluded were patients who had not undergone BT (brachytherapy) and treated with palliative intent. We offer two types of treatment for locally advanced cervical cancer: (a) radiochemotherapy followed by surgery and (b) exclusive radiochemotherapy. Imaging tests follow the presence of tumor and tumor size (width and thickness). Each examination was performed by a different physician who had no knowledge of the others’ findings. All patients underwent MRI prior to EBRT (external beam radiation therapy) while 18 of them also at the time of the first brachytherapy application. For the analysis we used the r-Pearson correlation coefficient. Results In 2013, 26 patients with cervical cancer were included. A total of 44 gynecological examinations were performed, 44 MRIs and 18 TRUSs. For the comparisons prior to EBRT the correlation coefficient between TRUS vs. MRI was r = 0.79 for AP and r = 0.83 for LL, for GYN vs. MRI was r = 0.6 for AP and r = 0.75 for LL. Prior to BT for GYN vs. MRI, r values were 0.60 and 0.63 for AP and LL, respectively; for GYN vs. TRUS, r values were 0.56 and 0.78 for AP and LL, respectively. Conclusions A high correlation between the three examinations was obtained. As such, TRUS can be considered a suitable method in the evaluation of tumor dimensions. PMID:25949227

  13. Comparison of particle-in-cell simulation with experiment for thetransport system of the superconducting electron cyclotron resonance ionsource VENUS

    SciTech Connect

    Todd, DamonS.; Leitner, Daniela; Leitner, Matthaeus; Lyneis,Claude M.; Qiang, Ji; Grote, Dave P.

    2005-09-19

    The three-dimensional, particle-in-cell code WARP has been enhanced to allow end-to-end beam dynamics simulations of the VENUS beam transport system from the extraction region, through a mass-analyzing magnet, and up to a two-axis emittance scanner. This paper presents first results of comparisons between simulation and experimental data. A helium beam (He+, He2+) is chosen as an initial comparison beam due to its simple mass spectrum. Although a number of simplifications are made for the initial extracted beam, aberration characteristics appear in simulations that are also present in experimental phase space current density measurements. Further, measurements of phase space tilt indicate that simulations must have little or no space charge neutralization along the transport system to best agree with experiment. In addition, recent measurements of triangular beam structure immediately after the source are presented. This beam structure is related to the source magnetic confinement fields and will need to be taken into account as the initial beam approximations are lifted.

  14. GaMin’11 – an international inter-laboratory comparison for geochemical CO₂ - saline fluid - mineral interaction experiments

    DOE PAGES

    Ostertag-Henning, C.; Risse, A.; Thomas, B.; ...

    2014-12-31

    Due to the strong interest in geochemical CO₂-fluid-rock interaction in the context of geological storage of CO₂ a growing number of research groups have used a variety of different experimental ways to identify important geochemical dissolution or precipitation reactions and – if possible – quantify the rates and extent of mineral or rock alteration. In this inter-laboratory comparison the gas-fluid-mineral reactions of three samples of rock-forming minerals have been investigated by 11 experimental labs. The reported results point to robust identification of the major processes in the experiments by most groups. The dissolution rates derived from the changes in compositionmore » of the aqueous phase are consistent overall, but the variation could be reduced by using similar corrections for changing parameters in the reaction cells over time. The comparison of experimental setups and procedures as well as of data corrections identified potential improvements for future gas-fluid-rock studies.« less

  15. Atmospheric Chemistry Experiment (ACE) Lower Stratospheric Trend Measurements: Approach and Preliminary Results based on Comparisons with ATMOS Midlatitude Observations

    NASA Astrophysics Data System (ADS)

    Rinsland, C. P.; Bernath, P. F.; McLeod, S.; Boone, C.; McHugh, M.; Walker, K.

    2003-12-01

    The Atmospheric Chemistry Experiment (ACE) was successfully launched on August 12, 2003, into a 73.9 degree inclined orbit at an altitude of 650 km onboard a U.S.-supplied Pegasus XL vehicle. The primary goal of the ACE mission is to measure solar occultation spectra from the UV to mid-infrared for a minimum of two years to determine whether or not the stratospheric ozone layer will begin to recover now that chlorofluorocarbon emissions have been banned. Among the instruments carried by the small Canadian-built satellite is a compact Fourier transform spectrometer designed to measure in the 750-4100 cm-1 region at 0.02 cm-1 spectral resolution. The measurements will provide an opportunity to determine lower stratospheric trends at midlatitudes by comparison of ACE measurements with measurements recorded by the Atmospheric Trace MOlecule Spectroscopy (ATMOS) Fourier transform spectometer at 0.01-cm-1 resolution during its first shuttle flight in 1985. We describe the approach to be used for trend determination, the status of the investigation, and the other data relevant for comparisons.

  16. Numerical Simulation of Steady and Pulsatile Flow Through Vascular Stenoses and Comparisons with Experiments Using Phase Contrast Magnetic Resonance Imaging

    NASA Astrophysics Data System (ADS)

    Behrens, Geoffrey; Agarwal, Ramesh; Moghaddam, Abbas N.; Choi, Eric T.; Amini, Amir A.

    2003-11-01

    A commercially available numerical flow solver "FLUENT" is employed in simulation of blood flow through vascular stenoses. Fluid properties are set to match those of the blood mimicking fluid used in flow phantom experiments at the Washington University School of Medicine. Computational results are compared for steady flow through axisymmetric and three-dimensional phantoms modeling mild to severe stenonses with the data collected using Phase Contrast Magnetic Resonance Imaging (PC-MRI) technique by colleagues in the CVIA laboratory at Washington University School of Medicine. Computations are also performed for pulsatile flow through vascular stenoses. Comparisons of PC-MRI and FLUENT output data show qualitative agreement in streamline patterns and good quantitative agreement for pressure drop across the stenoses.

  17. Copper Tube Compression in Z-Current Geometry, Numerical Simulations and Comparison with Cyclope Experiments

    SciTech Connect

    Lefrancois, A.; L'Eplattenier, P.; Burger, M.

    2006-02-13

    Metallic tubes compressions in Z-current geometry were performed at the Cyclope facility from Gramat Research Center in order to study the behavior of metals under large strain at high strain rate. 3D configurations of cylinder compressions have been calculated here to benchmark the new beta version of the electromagnetism package coupled with the dynamics in Ls-Dyna and compared with the Cyclope experiments. The electromagnetism module is being developed in the general-purpose explicit and implicit finite element program LS-DYNA{reg_sign} in order to perform coupled mechanical/thermal/electromagnetism simulations. The Maxwell equations are solved using a Finite Element Method (FEM) for the solid conductors coupled with a Boundary Element Method (BEM) for the surrounding air (or vacuum). More details can be read in the references.

  18. Isentropic Compression with a Rectangular Configuration for Tungstene and Tantalum, Computations and Comparison with Experiments

    SciTech Connect

    Lefrancois, A.; Reisman, D. B.; Bastea, M.; L'Eplattenier, P.; Burger, M.

    2006-02-13

    Isentropic compression experiments and numerical simulations on metals are performed at Z accelerator facility from Sandia National Laboratory and at Lawrence Livermore National Laboratory in order to study the isentrope, associated Hugoniot and phase changes of these metals. 3D configurations have been calculated here to benchmark the new beta version of the electromagnetism package coupled with the dynamics in Ls-Dyna and compared with the ICE Z shots 1511 and 1555. The electromagnetism module is being developed in the general-purpose explicit and implicit finite element program LS-DYNA{reg_sign} in order to perform coupled mechanical/thermal/electromagnetism simulations. The Maxwell equations are solved using a Finite Element Method (FEM) for the solid conductors coupled with a Boundary Element Method (BEM) for the surrounding air (or vacuum). More details can be read in the references.

  19. Isentropic Compression up to 200 KBars for LX 04, Numerical Simulations and Comparison with Experiments

    SciTech Connect

    Lefrancois, A.; Hare, D.; L'Eplattenier, P.; Burger, M.

    2006-02-13

    Isentropic compression experiments and numerical simulations on LX-04 (HMX / Viton 85/15) were performed respectively at Z accelerator facility from Sandia National Laboratory and at Lawrence Livermore National Laboratory in order to study the isentrope and associated Hugoniot of this HE. 2D and 3D configurations have been calculated here to test the new beta version of the electromagnetism package coupled with the dynamics in Ls-Dyna and compared with the ICE Z shot 1067 on LX 04. The electromagnetism module is being developed in the general-purpose explicit and implicit finite element program LS-DYNA{reg_sign} in order to perform coupled mechanical/thermal/electromagnetism simulations. The Maxwell equations are solved using a Finite Element Method (FEM) for the solid conductors coupled with a Boundary Element Method (BEM) for the surrounding air (or vacuum). More details can be read in the references.

  20. The ``Pen`` penetration analysis code: Comparison with experiments and with CALE calculations

    SciTech Connect

    Simonson, S.C. III

    1993-04-01

    The ``Pen`` computer program has been developed for the analysis of penetration by shaped charge jets. In addition to standard methods for calculating the depth of penetration and the radius of the hole produced by a stretching jet, Pen contains new methods for treating the onset of particulation and for calculating the depth of penetration by a particulated jet. A Pen analysis was compared with a detailed calculation carried out with the LLNL Arbitrary Lagrangian-Eulerian code CALE. Pen was also applied to the analysis of two shaped charge jet penetration experiments. Pen reproduced the CALE hole profile and the experimental profiles when the effective strength in the steel targets was set to 1.2--1.3 times the yield strength. An experimental value of 1.44 {plus_minus} 0.19 GPa was obtained for the effective strength of hardened A4340 steel under jet impact.

  1. Long-term effects of traumatic experience: Comparison study in the adolescent IDPs in Serbia.

    PubMed

    Matsunaga, Chieko; Ristic, Dragana; Niregi, Mitsuki

    2006-12-01

    The purpose of this study is to examine the long term psychological effects of war stress regarded as traumatic experience. The subjects are Serbian internally displaced people (IDP) of adolescent population from Kosovo. It is a very big concern whether the adolescents would overcome the social and psychological difficulties caused by the war stress in order to reconstruct the better society. The result came out that the long-term effects still exist in PTSD, depression and hopelessness, which affects self-esteem and the attitude in purpose in life that are important factors for personality development. This paper also examines the difference between IDPs with war stress and the adolescent sufferers of the big earthquake in Japan.

  2. Revisited comparison of thermal instability theory with MARFE density limit experiment in TEXTOR.

    NASA Astrophysics Data System (ADS)

    Kelly, Frederick

    2006-03-01

    Density limit shots in TEXTOR [Tokamak EXperiment for Technology Oriented Research] that ended in MARFE [Multifaceted Asymmetric Radiation From the Edge] are analyzed by several thermal instability theories^1-7 with convective effects included. ^1W. M. Stacey, Phys. Plasmas 3, 2673 (1996); Phys. Plasmas 3, 3032 (1996); Phys. Plasmas 4, 134 (1997); Phys. Plasmas 4, 242 (1997). ^2W. M. Stacey, Plasma Phys. Contr. Fusion 39, 1245 (1997). ^3W. M. Stacey, Fusion Technol. 36, 38 (1999).^ ^4W. M. Stacey, Phys. Plasmas 7, 3464 (2000). ^5F. A. Kelly, W. M. Stacey, J. Rapp and M. Brix, Phys. Plasmas 8, 3382 (2001). ^6M. Z. Tokar and F. A. Kelly, Phys. Plasmas 10, 4378 (2003). ^7M. Z. Tokar, F. A. Kelly and X. Loozen, Phys. Plasmas 12, 052510 (2005).

  3. Hemolysis Related to Turbulent Eddy Size Distributions Using Comparisons of Experiments to Computations.

    PubMed

    Ozturk, Mesude; O'Rear, Edgar A; Papavassiliou, Dimitrios V

    2015-12-01

    Turbulent blood flow in medical devices contributes to blood trauma, yet the exact mechanism(s) have not been fully elucidated. Local turbulent stresses, viscous stresses, and the rate of dissipation of the turbulent kinetic energy have been proffered as hypotheses to describe and predict blood damage. In this work, simulations of experiments in a Couette flow viscometer and a capillary tube were used to examine extensive properties of the turbulent flow field and to investigate contributing factors for red blood cell hemoglobin release in turbulence by eddy analysis. It was found that hemolysis occurred when dissipative eddies were comparable in size to the red blood cells. The Kolmogorov length scale was used to quantify the size of smaller turbulent eddies, indicating correspondence of hemolysis with number and surface area of eddies smaller than about 10 μm when a k-ε turbulence model is adopted.

  4. Calculated rotation-bending energy levels of CH 5+ and a comparison with experiment

    NASA Astrophysics Data System (ADS)

    Wang, Xiao-Gang; Carrington, Tucker

    2016-05-01

    We report J > 0 CH 5+ levels computed by fixing stretch coordinates. They are computed by using a simple product basis, exploiting symmetry, and carefully parallelizing the calculation. The J > 0 CH 5+ levels are compared with those obtained from other theoretical methods and with experimental ground state combination differences of Asvany et al. [Science, 347, 1346 (2015)]. If the assignment of Asvany et al. is correct, there are important differences between the levels we compute and those observed. We propose a different assignment of the experimental levels that reduces the maximum error from 34 to 2 cm-1. The new assignment can only be correct if states of both parities exist in the experiment. Although, ro-vibrational levels of CH 5+ cannot be associated with individual vibrational states, they do occur in blocks separated by gaps.

  5. A SUPG approach for determining frontlines in aluminium extrusion simulations and a comparison with experiments

    SciTech Connect

    Koopman, A. J.; Geijselaers, H. J. M.; Huetink, J.; Nilsen, K. E.; Koenis, P. T. G.

    2007-04-07

    In this paper we present a method to determine the frontlines inside the container and inside the extrusion die based on a steady state velocity field. Using this velocity field the convection equation is solved with a SUPG stabilized finite element method for a variable that represents the time it takes from the initial front to a certain point in the domain. When iso-lines in this field are plotted the development of fronts can be tracked. Extrusion experiments are performed with aluminium billets cut in slices. When extrusion is stopped the billet and extrudate are removed from the container and cut in half in the extrusion direction, copper foils between the slices show the frontlines. These lines show good agreement with the iso-lines from the numerical solution of convection equation.

  6. [Comparison of different G-CSF treatment effectiveness in experiments on irradiated mice].

    PubMed

    Rozhdestvenskiĭ, L M; Shchegoleva, R A; Deshevoĭ, Iu B; Lisina, N I; Titov, B A

    2012-01-01

    In the experiments on F1 (CBA x C57BL) and BALB mice irradiated by 137Cs gamma-rays, preparations of unglycosilated G-SCF such as Neupogen and their domestic analogs Leucostim and Neupomax were investigated. The tests such as 9-day bone marrow cellularity (BMC) and endogenous CFUs, the neutrophile number restoration, the 30-day survival index have shown that all three preparations have an approximately equal effectiveness relating to acute radiation disease treatment and granulopoiesis stimulation after a 5-10 day consecutive administration following irradiation of mice at lethal and sublethal doses. We have come to the conclusion that Leucostim and Neupomax can be regarded as adequate substitutes for Neupogen.

  7. Polarized x-ray-absorption spectroscopy of the uranyl ion: Comparison of experiment and theory

    SciTech Connect

    Hudson, E.A.; Allen, P.G.; Terminello, L.J.; Denecke, M.A.; Reich, T.

    1996-07-01

    The x-ray linear dichroism of the uranyl ion (UO{sub 2}{sup 2+}) in uranium {ital L}{sub 3}-edge extended x-ray-absorption fine structure (EXAFS), and {ital L}{sub 1}- and {ital L}{sub 3}-edge x-ray-absorption near-edge structure (XANES), has been investigated both by experiment and theory. A striking polarization dependence is observed in the experimental XANES and EXAFS for an oriented single crystal of uranyl acetate dihydrate [UO{sub 2}(CH{sub 3}CO{sub 2}){sub 2}{center_dot}2H{sub 2}O], with the x-ray polarization vector aligned either parallel or perpendicular to the bond axis of the linear uranyl cation (O-U-O). Single-crystal results are compared to experimental spectra for a polycrystalline uranyl acetate sample and to calculations using the {ital ab} {ital initio} multiple-scattering (MS) code FEFF 6. Theoretical XANES spectra for uranyl fluoride (UO{sub 2}F{sub 2}) reproduce all the features of the measured uranyl acetate spectra. By identifying scattering paths which contribute to individual features in the calculated spectrum, a detailed understanding of the {ital L}{sub 1}-edge XANES is obtained. MS paths within the uranyl cation have a notable influence upon the XANES. The measured {ital L}{sub 3}-edge EXAFS is also influenced by MS, especially when the x-ray polarization is parallel to the uranyl species. These MS contributions are extracted from the total EXAFS and compared to calculations. The best agreement with the isolated MS signal is obtained by using nonoverlapped muffin-tin spheres in the FEFF 6 calculation. This contrasts the {ital L}{sub 1}-edge XANES calculations, in which overlapping was required for the best agreement with experiment. {copyright} {ital 1996 The American Physical Society.}

  8. Physical mechanism of the Schwarzschild effect in film dosimetry—theoretical model and comparison with experiments

    NASA Astrophysics Data System (ADS)

    Djouguela, A.; Kollhoff, R.; Rühmann, A.; Willborn, K. C.; Harder, D.; Poppe, B.

    2006-09-01

    In consideration of the importance of film dosimetry for the dosimetric verification of IMRT treatment plans, the Schwarzschild effect or failure of the reciprocity law, i.e. the reduction of the net optical density under 'protraction' or 'fractionation' conditions at constant dose, has been experimentally studied for Kodak XOMAT-V (Martens et al 2002 Phys. Med. Biol. 47 2221-34) and EDR 2 dosimetry films (Djouguela et al 2005 Phys. Med. Biol. 50 N317-N321). It is known that this effect results from the competition between two solid-state physics reactions involved in the latent-image formation of the AgBr crystals, the aggregation of two Ag atoms freshly formed from Ag+ ions near radiation-induced occupied electron traps and the spontaneous decomposition of the Ag atoms. In this paper, we are developing a mathematical model of this mechanism which shows that the interplay of the mean lifetime τ of the Ag atoms with the time pattern of the irradiation determines the magnitude of the observed effects of the temporal dose distribution on the net optical density. By comparing this theory with our previous protraction experiments and recent fractionation experiments in which the duration of the pause between fractions was varied, a value of the time constant τ of roughly 10 s at room temperature has been determined for EDR 2. The numerical magnitude of the Schwarzschild effect in dosimetry films under the conditions generally met in radiotherapy amounts to only a few per cent of the net optical density (net OD), so that it can frequently be neglected from the viewpoint of clinical applications. But knowledge of the solid-state physical mechanism and a description in terms of a mathematical model involving a typical time constant of about 10 s are now available to estimate the magnitude of the effect should the necessity arise, i.e. in cases of large fluctuations of the temporal pattern of film exposure.

  9. Comparison of Primary Care Experiences in Village Clinics with Different Ownership Models in Guangdong Province, China

    PubMed Central

    Feng, Shanshan; Shi, Leiyu; Zeng, Jiazhi; Chen, Wen; Ling, Li

    2017-01-01

    Objectives In order to improve the quality of services at village clinics (VCs), which are important primary care service providers in rural China, the Chinese government has encouraged the township hospitals to own and manage VCs. There are currently three models of ownership and management of VCs: township hospital-owned and -managed (HVC), village committee-owned and -managed (VVC), and private-owned and -managed (PVC). This study aims to examine the association between these ownership models of VCs and patients' primary care experiences. Methods Villagers were selected by multistage stratified sampling and their experiences with primary care were measured using the Primary Care Assessment Tool—Adult Edition (PCAT-AS). Data were collected through face-to-face interviews and the questionnaires administered by investigators in the cross-sectional study from February to April 2015. The PCAT scores were compared among the three models by covariance analysis, and multiple linear regression was used to analyze factors associated with the PCAT total scores. Results A total of 1491 questionnaires were collected. After controlling for covariates, HVCs reported the highest PCAT scores and satisfaction rate. In terms of the domains, HVC reported the highest scores in the coordination and comprehensiveness domains, while PVC had the highest scores in the first contact-accessibility domain. Multivariate linear regression showed that HVC, married participants, aged 60 and older, satisfied with the services, receiving six or more visits, and those with medical expenditures over 20% of their total family expenditures, were also positively associated with better primary care quality. Conclusions This study demonstrates that villagers receiving medical care at HVCs perceived better primary care than those at PVCs and VVCs. In order to improve the quality of primary care at VCs, it is necessary to increase government subsidies for public service packages, tighten the township

  10. Melts of garnet lherzolite: experiments, models and comparison to melts of pyroxenite and carbonated lherzolite

    USGS Publications Warehouse

    Grove, Timothy L.; Holbig, Eva S.; Barr, Jay A.; Till, Christy B.; Krawczynski, Michael J.

    2013-01-01

    Phase equilibrium experiments on a compositionally modified olivine leucitite from the Tibetan plateau have been carried out from 2.2 to 2.8 GPa and 1,380–1,480 °C. The experiments-produced liquids multiply saturated with spinel and garnet lherzolite phase assemblages (olivine, orthopyroxene, clinopyroxene and spinel ± garnet) under nominally anhydrous conditions. These SiO2-undersaturated liquids and published experimental data are utilized to develop a predictive model for garnet lherzolite melting of compositionally variable mantle under anhydrous conditions over the pressure range of 1.9–6 GPa. The model estimates the major element compositions of garnet-saturated melts for a range of mantle lherzolite compositions and predicts the conditions of the spinel to garnet lherzolite phase transition for natural peridotite compositions at above-solidus temperatures and pressures. We compare our predicted garnet lherzolite melts to those of pyroxenite and carbonated lherzolite and develop criteria for distinguishing among melts of these different source types. We also use the model in conjunction with a published predictive model for plagioclase and spinel lherzolite to characterize the differences in major element composition for melts in the plagioclase, spinel and garnet facies and develop tests to distinguish between melts of these three lherzolite facies based on major elements. The model is applied to understand the source materials and conditions of melting for high-K lavas erupted in the Tibetan plateau, basanite–nephelinite lavas erupted early in the evolution of Kilauea volcano, Hawaii, as well as younger tholeiitic to alkali lavas from Kilauea.

  11. Assessing patient experiences in the pediatric patient-centered medical home: a comparison of two instruments.

    PubMed

    Knapp, Caprice; Chakravorty, Shourjo; Madden, Vanessa; Baron-Lee, Jacqueline; Gubernick, Ruth; Kairys, Steven; Pelaez-Velez, Cristina; Sanders, Lee M; Thompson, Lindsay

    2014-11-01

    The Patient-Centered Medical Home (PCMH) is a model of care that has been promoted as a way to transform a broken primary care system in the US. However, in order to convince more practices to make the transformation and to properly reimburse practices who are PCMHs, valid and reliable data are needed. Data that capture patient experiences in a PCMH is valuable, but which instrument should be used remains unclear. Our study aims to compare the validity and reliability of two national PCMH instruments. Telephone surveys were conducted with children who receive care from 20 pediatric practices across Florida (n = 990). All of the children are eligible for Medicaid or the Children's Health Insurance Program. Analyses were conducted to compare the Consumer Assessment of Health Plan Survey-Patient-Centered Medical Home (CAHPS-PCMH) and the National Survey of Children with Special Health Care Needs (NS-CSHCN) medical home domain. Respondents were mainly White non-Hispanic, female, under 35 years old, and from a two-parent household. The NS-CSHCN outperformed the CAHPS-PCMH in regard to scale reliability (Cronbach's alpha coefficients all ≥0.81 vs. 0.56-0.85, respectively). In regard to item-domain convergence and discriminant validity the CAHPS-PCMH fared better than the NS-CSHCN (range of convergence 0.66-0.93 vs. 0.32-1.00). The CAHPS-PCMH did not correspond to the scale structure in construct validity testing. Neither instrument performed well in the known-groups validity tests. No clear best instrument was determined. Further revision and calibration may be needed to accurately assess patient experiences in the PCMH.

  12. Multi-channel transport experiments at Alcator C-Mod and comparison with gyrokinetic simulations

    SciTech Connect

    White, A. E.; Howard, N. T.; Greenwald, M.; Reinke, M. L.; Sung, C.; Baek, S.; Barnes, M.; Dominguez, A.; Ernst, D.; Gao, C.; Hubbard, A. E.; Hughes, J. W.; Lin, Y.; Parra, F.; Porkolab, M.; Rice, J. E.; Walk, J.; Wukitch, S. J.; Team, Alcator C-Mod; Candy, J.; and others

    2013-05-15

    Multi-channel transport experiments have been conducted in auxiliary heated (Ion Cyclotron Range of Frequencies) L-mode plasmas at Alcator C-Mod [Marmar and Alcator C-Mod Group, Fusion Sci. Technol. 51(3), 3261 (2007)]. These plasmas provide good diagnostic coverage for measurements of kinetic profiles, impurity transport, and turbulence (electron temperature and density fluctuations). In the experiments, a steady sawtoothing L-mode plasma with 1.2 MW of on-axis RF heating is established and density is scanned by 20%. Measured rotation profiles change from peaked to hollow in shape as density is increased, but electron density and impurity profiles remain peaked. Ion or electron heat fluxes from the two plasmas are the same. The experimental results are compared directly to nonlinear gyrokinetic theory using synthetic diagnostics and the code GYRO [Candy and Waltz, J. Comput. Phys. 186, 545 (2003)]. We find good agreement with experimental ion heat flux, impurity particle transport, and trends in the fluctuation level ratio (T(tilde sign){sub e}/T{sub e})/(ñ{sub e}/n{sub e}), but underprediction of electron heat flux. We find that changes in momentum transport (rotation profiles changing from peaked to hollow) do not correlate with changes in particle transport, and also do not correlate with changes in linear mode dominance, e.g., Ion Temperature Gradient versus Trapped Electron Mode. The new C-Mod results suggest that the drives for momentum transport differ from drives for heat and particle transport. The experimental results are inconsistent with present quasilinear models, and the strong sensitivity of core rotation to density remains unexplained.

  13. Comparisons of physical experiment and discrete element simulations of sheared granular materials in an annular shear cell

    USGS Publications Warehouse

    Ji, S.; Hanes, D.M.; Shen, H.H.

    2009-01-01

    In this study, we report a direct comparison between a physical test and a computer simulation of rapidly sheared granular materials. An annular shear cell experiment was conducted. All parameters were kept the same between the physical and the computational systems to the extent possible. Artificially softened particles were used in the simulation to reduce the computational time to a manageable level. Sensitivity study on the particle stiffness ensured such artificial modification was acceptable. In the experiment, a range of normal stress was applied to a given amount of particles sheared in an annular trough with a range of controlled shear speed. Two types of particles, glass and Delrin, were used in the experiment. Qualitatively, the required torque to shear the materials under different rotational speed compared well with those in the physical experiments for both the glass and the Delrin particles. However, the quantitative discrepancies between the measured and simulated shear stresses were nearly a factor of two. Boundary conditions, particle size distribution, particle damping and friction, including a sliding and rolling, contact force model, were examined to determine their effects on the computational results. It was found that of the above, the rolling friction between particles had the most significant effect on the macro stress level. This study shows that discrete element simulation is a viable method for engineering design for granular material systems. Particle level information is needed to properly conduct these simulations. However, not all particle level information is equally important in the study regime. Rolling friction, which is not commonly considered in many discrete element models, appears to play an important role. ?? 2009 Elsevier Ltd.

  14. Vibrational non-equilibrium in the hydrogen-oxygen reaction. Comparison with experiment

    NASA Astrophysics Data System (ADS)

    Skrebkov, Oleg V.

    2015-03-01

    A theoretical model is proposed for the chemical and vibrational kinetics of hydrogen oxidation based on consistent accounting of the vibrational non-equilibrium of the HO2 radical that forms as a result of the bimolecular recombination H+O2 → HO2. In the proposed model, the chain branching H+O2 = O+OH and inhibiting H+O2+M = HO2+M formal reactions are treated (in the terms of elementary processes) as a single multi-channel process of forming, intramolecular energy redistribution between modes, relaxation, and unimolecular decay of the comparatively long-lived vibrationally excited HO2 radical, which is able to react and exchange energy with the other components of the mixture. The model takes into account the vibrational non-equilibrium of the starting (primary) H2 and O2 molecules, as well as the most important molecular intermediates HO2, OH, O2(1Δ), and the main reaction product H2O. It is shown that the hydrogen-oxygen reaction proceeds in the absence of vibrational equilibrium, and the vibrationally excited HO2(v) radical acts as a key intermediate in a fundamentally important chain branching process and in the generation of electronically excited species O2(1Δ), O(1D), and OH(2Σ+). The calculated results are compared with the shock tube experimental data for strongly diluted H2-O2 mixtures at 1000 < T < 2500 K, 0.5 < p < 4 atm. It is demonstrated that this approach is promising from the standpoint of reconciling the predictions of the theoretical model with experimental data obtained by different authors for various compositions and conditions using different methods. For T < 1500 K, the nature of the hydrogen-oxygen reaction is especially non-equilibrium, and the vibrational non-equilibrium of the HO2 radical is the essence of this process. The quantitative estimation of the vibrational relaxation characteristic time of the HO2 radical in its collisions with H2 molecules has been obtained as a result of the comparison of different experimental data on

  15. Soot Particle Optical Properties: a Comparison between Numerical Calculations and Experimental Data Collected during the Boston College Experiment

    NASA Astrophysics Data System (ADS)

    Sharma, N.; Mazzoleni, C.; China, S.; Dubey, M. K.; Onasch, T. B.; Cross, E. S.; Davidovits, P.; Wrobel, W.; Ahern, A.; Schwarz, J. P.; Spackman, J. R.; Lack, D. A.; Massoli, P.; Freedman, A.; Olfert, J. S.; Freitag, S.; Sedlacek, A. J.; Cappa, C. D.; Subramanian, R.

    2010-12-01

    A black carbon instrument inter-comparison study was conducted in July 2008 at Boston College to measure the optical, physical and chemical properties of laboratory generated soot under controlled conditions [1]. The physical, chemical and optical properties were measured on size-selected particles for: 1. Nascent soot particles 2. Nascent- denuded soot particles 3. Soot particles coated with sulfuric acid or DOS (dioctyl sebacate) across a range of coating thicknesses 4. Coated and then denuded soot particles. Instruments involved in the inter-comparison study fell into two broad categories: a) mass-based instruments and b) optically-based instruments. During this experiment, 7 mass-based and 9 optically-based instruments were deployed. Absorption scattering and extinction measurements were carried out in combination with mass-based instruments in order to obtain absorption, scattering and extinction coefficients for coated and denuded soot particles as a function of their mass, size and coating thickness. Particle samples were also collected on nuclepore filters to perform Scanning Electron Microscopy (SEM) analysis. The images obtained with the SEM elucidated the changes in particle morphology upon coating and denuding. The images were also used to determine morphological parameters for single soot aggregates (e.g. monomers number and diameter) used in the numerical estimation of aerosol optical properties. With the data collected during the experiment, we carry out a comparative study of the optical properties of soot particles obtained experimentally with those calculated using the two most commonly used numerical approximations (Rayleigh-Debye-Gans (RDG) theory and Mie theory). Thus we validate the degree of agreement between theoretical models and experimental results. The laboratory optical, mass, size and morphological data can be used to elucidate the impact of these parameters on radiative forcing by atmospheric soot [2, 3]. References: 1. Cross, E. S

  16. Modelling of a viscoplastic granular column collapse and comparison with experiments

    NASA Astrophysics Data System (ADS)

    Martin, Nathan; Ionescu, Ioan; Mangeney, Anne; Bouchut, François; Roche, Olivier; Farin, Maxime

    2015-04-01

    Landslides and, more generally, large scale granular flows, represent a wide variety of geophysical flows also including mud or debris flow and snow avalanches. In a continuum mechanics context, the accurate simulation of these flows strongly depends on the modelling of their rheology and their boundary conditions, namely the sliding law and processes of erosion. In particular the description of the static and of the flowing states of granular media is still an open issue. We focus here on the quantitative reproduction of laboratory experiments using a mechanical and numerical model of dry granular flows with the so-called μ(I) rheology associated to a Drucker-Prager plasticity criterion and a shear rate and pressure dependent viscosity η(||D||,p). A Coulomb type friction law is considered at the base of the flow. The modelling is achieved in a finite-element context using the software FreeFem++. The simulations are bidimensionnal and well reproduce quantitatively both the dynamical and final shapes of the deposit. The effects of the sidewalls of the experimental channel, neglected in 2D simulations, are investigated by introducing an extra term in the equations varying with the inverse of the width of the channel, providing an enhanced agreement with the experiments. The numerical results show that the flow is essentially located in a surface layer behind the front, while the whole granular material is flowing near the front where basal sliding occurs. The static/flowing interface changes as a function of space and time, in good agreement with experimental observations. The resulting dynamic viscosity varies from very small values near the free surface and near the front to 1.5Pa.s within the quasi-static zone. The results show a rather small yet computationnaly expensive difference between a constant viscosity model and a μ(I) rheology in the case of a rigid bed. This has important implication for application to real geophysical flows. The role of an erodible

  17. Gasoline surrogate modeling of gasoline ignition in a rapid compression machine and comparison to experiments

    SciTech Connect

    Mehl, M; Kukkadapu, G; Kumar, K; Sarathy, S M; Pitz, W J; Sung, S J

    2011-09-15

    The use of gasoline in homogeneous charge compression ignition engines (HCCI) and in duel fuel diesel - gasoline engines, has increased the need to understand its compression ignition processes under engine-like conditions. These processes need to be studied under well-controlled conditions in order to quantify low temperature heat release and to provide fundamental validation data for chemical kinetic models. With this in mind, an experimental campaign has been undertaken in a rapid compression machine (RCM) to measure the ignition of gasoline mixtures over a wide range of compression temperatures and for different compression pressures. By measuring the pressure history during ignition, information on the first stage ignition (when observed) and second stage ignition are captured along with information on the phasing of the heat release. Heat release processes during ignition are important because gasoline is known to exhibit low temperature heat release, intermediate temperature heat release and high temperature heat release. In an HCCI engine, the occurrence of low-temperature and intermediate-temperature heat release can be exploited to obtain higher load operation and has become a topic of much interest for engine researchers. Consequently, it is important to understand these processes under well-controlled conditions. A four-component gasoline surrogate model (including n-heptane, iso-octane, toluene, and 2-pentene) has been developed to simulate real gasolines. An appropriate surrogate mixture of the four components has been developed to simulate the specific gasoline used in the RCM experiments. This chemical kinetic surrogate model was then used to simulate the RCM experimental results for real gasoline. The experimental and modeling results covered ultra-lean to stoichiometric mixtures, compressed temperatures of 640-950 K, and compression pressures of 20 and 40 bar. The agreement between the experiments and model is encouraging in terms of first

  18. The Influence of the Family on Adolescent Sexual Experience: A Comparison between Baltimore and Johannesburg

    PubMed Central

    Mmari, Kristin; Kalamar, Amanda M.; Brahmbhatt, Heena; Venables, Emilie

    2016-01-01

    The main objective of this paper is to understand the role of the family on the sexual experiences of adolescents from urban, disadvantaged settings in Baltimore and Johannesburg. Data were collected as part of the WAVE study, a global study of disadvantaged youth in five cities. Qualitative data were based on key informant interviews, a Photovoice exercise, community mapping, focus groups and in-depth interviews with adolescents. Quantitative data were gathered from an ACASI survey that was administered to approximately 450–500 adolescents per site. Results from the qualitative data revealed that while parents were viewed as important sources of information for sexual and reproductive health, they were often not present in the adolescents’ lives. This lack of parental presence was perceived to result in adolescents feeling an overall lack of adult support and guidance. The impact of parental presence and support on adolescent sexual experience was further examined from the quantitative data and revealed a complex picture. In both Baltimore and Johannesburg, female adolescents who were raised by other relatives were less likely to report having had sex compared to those raised by two biological parents, which was not observed for males. In Johannesburg, female adolescents who were paternal orphans were less likely to have had sex compared to non-orphans; the opposite was true among males. Finally, in both sites, female adolescents who had been exposed to violence were more likely to have had sex compared to those who had not; for males, there was no significant relationship. The study demonstrates the powerful influence of both context and gender for understanding the influences of the family on adolescent sexual behaviors. Programs aiming to reduce adolescent sexual risk behaviors the need to understand the complex influences on risk behaviors in different settings and in particular, the role of mothers and fathers. Prevention strategies need to also

  19. Soluble renormalised model of atom-molecular Feshbach resonance: comparison to experiment

    NASA Astrophysics Data System (ADS)

    Drummond, Peter; Kheruntsyan, Karen

    2003-05-01

    We consider an effective quantum field Hamiltonian [1] as a generic model of molecule formation from pairs of atoms in a Bose-Einstein condensate near a Feshbach resonance. This point-contact model can be renormalised exactly and non-perturbatively [2]. It also has an exact analytic solution for the two-particle ground state. In this case the ground state is a coherent quantum superposition of a molecule with a pair of atoms. We find that the resulting molecular binding energy is in remarkable agreement with inferred binding energies observed in the recent Ramsey-fringe style interference measurement of Donley et al. [3]. The exact solubility of this universal and simple field-theoretic model means that one can obtain analytic expressions for all relevant quantities including the binding energy and the fraction of molecules involved. Our conclusion is that, provided they are renormalised, the use of field theoretic models can allow a quantitative picture of Feshbach molecule formation experiments without requiring a detailed molecular calculation for each specific molecule. [1] P.D.Drummond, K.V.Kheruntsyan, and H.He, Phys. Rev. Lett. 81, 3055 (1998). [2] S.J.J.M.F.Kokkelmans and M.J.Holland, Phys. Rev. Lett. 18, 180401 (2002). [3] E.A.Donley et al., Nature 417, 529 (2002).

  20. Simulating Thermal Explosion of Octahydrotetranitrotetrazine-based explosives: Model Comparison with Experiment

    SciTech Connect

    Yoh, J J; McClelland, M A; Maienschein, J L; Nichols, A L; Tarver, C M

    2006-02-07

    The authors compare two-dimensional model results with measurements for the thermal, chemical and mechanical behavior in a thermal explosion experiment. Confined high explosives are heated at a rate of 1 C per hour until an explosion is observed. The heating, ignition, and deflagration phases are modeled using an Arbitrarily Lagrangian-Eulerian code (ALE3D) that can handle a wide range of time scales that vary from a structural to a dynamic hydro time scale. During the pre-ignition phase, quasi-static mechanics and diffusive thermal transfer from a heat source to the HE are coupled with the finite chemical reactions that include both endothermic and exothermic processes. Once the HE ignites, a hydro dynamic calculation is performed as a burn front propagates through the HE. Two octahydrotetranitrotetrazine (HMX)-based explosives, LX-04 and LX-10, are considered, whose chemical-thermal-mechanical models are constructed based on measurements of thermal and mechanical properties along with small scale thermal explosion measurements. The present HMX modeling work shows very first violence calculations with thermal predictions associated with a confined thermal explosion test. The simulated dynamic response of HE confinement during the explosive phase is compared to measurements in larger scale thermal explosion tests. The explosion temperatures for both HE's are predicted to within 1 C. Calculated and measured wall strains provide an indication of vessel pressurization during the heating phase and violence during the explosive phase.

  1. Calculations of ADS with deep subcritical uranium active cores - comparison with experiments and predictions

    NASA Astrophysics Data System (ADS)

    Zhivkov, P.; Furman, W.; Stoyanov, Ch

    2014-09-01

    The main characteristics of the neutron field formed within the massive (512 kg) natural uranium target assembly (TA) QUINTA irradiated by deuteron beam of JINR Nuclotron with energies 1,2,4, and 8 GeV as well as the spatial distributions and the integral numbers of (n,f), (n,γ) and (n,xn)- reactions were calculated and compared with experimental data [1] . The MCNPX 27e code with ISABEL/ABLA/FLUKA and INCL4/ABLA models of intra-nuclear cascade (INC) and experimental cross-sections of the corresponding reactions were used. Special attention was paid to the elucidation of the role of charged particles (protons and pions) in the fission of natural uranium of TA QUINTA. Extensive calculations have been done for quasi-infinite (with very small neutron leakage) depleted uranium TA BURAN having mass about 20 t which are intended to be used in experiments at Nuclotron in 2014-2016. As in the case of TA QUINTA which really models the central zone of TA BURAN the total numbers of fissions, produced 239Pu nuclei and total neutron multiplicities are predicted to be proportional to proton or deuteron energy up to 12 GeV. But obtained values of beam power gain are practically constant in studied incident energy range and are approximately four. These values are in contradiction with the experimental result [2] obtained for the depleted uranium core weighting three tons at incident proton energy 0.66 GeV.

  2. Preparing beginning reading teachers: An experimental comparison of initial early literacy field experiences

    PubMed Central

    Lake, Vickie E.; Greulich, Luana; Folsom, Jessica S.; Guidry, Lisa

    2012-01-01

    This randomized-control trial examined the learning of preservice teachers taking an initial Early Literacy course in an early childhood education program and of the kindergarten or first grade students they tutored in their field experience. Preservice teachers were randomly assigned to one of two tutoring programs: Book Buddies and Tutor Assisted Intensive Learning Strategies (TAILS), which provided identical meaning-focused instruction (shared book reading), but differed in the presentation of code-focused skills. TAILS used explicit, scripted lessons, and the Book Buddies required that code-focused instruction take place during shared book reading. Our research goal was to understand which tutoring program would be most effective in improving knowledge about reading, lead to broad and deep language and preparedness of the novice preservice teachers, and yield the most successful student reading outcomes. Findings indicate that all pre-service teachers demonstrated similar gains in knowledge, but preservice teachers in the TAILS program demonstrated broader and deeper application of knowledge and higher self-ratings of preparedness to teach reading. Students in both conditions made similar comprehension gains, but students tutored with TAILS showed significantly stronger decoding gains. PMID:24204096

  3. Comparison Experiments of Different Model Error Schemes in Ensemble Kalman Filter Soil Moisture Assimilation

    NASA Astrophysics Data System (ADS)

    Nie, Suping; Zhu, Jiang; Luo, Yong

    2010-05-01

    The purpose of this study is to explore the performances of different model error scheme in soil moisture data assimilation. Based on the ensemble Kalman filter (EnKF) and the atmosphere-vegetation interaction model (AVIM), point-scale analysis results for three schemes, 1) covariance inflation (CI), 2) direct random disturbance (DRD), and 3) error source random disturbance (ESRD), are combined under conditions of different observational error estimations, different observation layers, and different observation intervals using a series of idealized experiments. The results shows that all these schemes obtain good assimilation results when the assumed observational error is an accurate statistical representation of the actual error used to perturb the original truth value, and the ESRD scheme has the least root mean square error (RMSE). Overestimation or underestimation of the observational errors can affect the assimilation results of CI and DRD schemes sensitively. The performances of these two schemes deteriorate obviously while the ESRD scheme keeps its capability well. When the observation layers or observation interval increase, the performances of both CI and DRD schemes decline evidently. But for the ESRD scheme, as it can assimilate multi-layer observations coordinately, the increased observations improve the assimilation results further. Moreover, as the ESRD scheme contains a certain amount of model error estimation functions in its assimilation process, it also has a good performance in assimilating sparse-time observations.

  4. Comparison of Abuse Experiences of Rural and Urban African American Women During Perinatal Period

    PubMed Central

    Bhandari, Shreya; Bullock, Linda F. C.; Richardson, Jeanita W.; Kimeto, Pamela; Campbell, Jacquelyn C.; Sharps, Phyllis W.

    2015-01-01

    A subsample of 12 African American women (6 urban and 6 rural) were selected from a larger longitudinal, randomized control trial, Domestic Violence Enhanced Home Visitation (DOVE-R01 900903 National Institute of Nursing Research [NINR]/National Institutes of Health [NIH]). All African American women were chosen to control for any racial- and/or race-related cultural differences that may exist among women across geographical areas. The experiences of abuse during the perinatal period are drawn from in-depth interviews conducted at five points in time during pregnancy and the post-partum period. The analysis describes three major themes that highlight the similarities and differences among rural and urban women. The main themes found were (1) types of abuse, (2) location of abuse, and (3) response to abuse. In addition, two sub-themes (a) defiance and compliance and (b) role of children were also identified. Implications for universal screening for women of reproductive age, safer gun laws, and the need for further research are discussed. PMID:25315478

  5. High-pressure study of binary thorium compounds from first principles theory and comparisons with experiment.

    PubMed

    Kanchana, V; Vaitheeswaran, G; Svane, A; Heathman, S; Gerward, L; Staun Olsen, J

    2014-06-01

    The high-pressure structural behaviour of a series of binary thorium compounds ThX (X = C, N, P, As, Sb, Bi, S, Se, Te) is studied using the all-electron full potential linear muffin-tin orbital (FP-LMTO) method within the generalized gradient approximation (GGA) for the exchange and correlation potential. The calculated equlibrium lattice parameters and bulk moduli, as well as the equations of state agree well with experimental results. New experiments are reported for ThBi and ThN. Calculations are performed for the ThX compounds in the NaCl- and CsCl-type crystal structures, and structural phase transitions from NaCl to CsCl are found in ThP, ThAs, ThSb and ThSe at pressures of 26.1, 22.1, 8.1 and 23.2 GPa, respectively, in excellent agreement with experimental results. ThC, ThN and ThS are found to be stable in the NaCl structure, and ThBi and ThTe in the CsCl structure, for pressures below 50 GPa. The electronic structures of the ThX compounds are studied using the quasiparticle self-consistent GW method (G: Green function, W: dynamically screened interaction).

  6. Comparison of Early and Delayed Laparoscopic Cholecystectomy for Acute Cholecystitis: Experience from A Single Center

    PubMed Central

    Gul, Rouf; Dar, Rayees Ahmad; Sheikh, Riyaz Ahmad; Salroo, Nazir Ahmad; Matoo, Adnan Rashid; Wani, Sabiya Hamid

    2013-01-01

    Background: Cholecystectomy for symptomatic gallstones is mainly performed after the acute cholecystitis episode settles because of the fear of higher morbidity and conversion from laparoscopic cholecystectomy to open cholecystectomy during acute cholecystitis. Aims: To evaluate the safety and feasibility of laparoscopic cholecystectomy for acute cholecystitis and to compare the results with delayed cholecystectomy. Materials and Methods: This was a prospective and randomized study. For patients assigned to early group, laparoscopic cholecystectomy was performed as soon as possible within 72 hours of admission. Patients in the delayed group were treated conservatively and discharged as soon as the acute attack subsided. They were subsequently readmitted for elective laparoscopic cholecystectomy 6-12 weeks later. Results: There was no significant difference in the conversion rates, postoperative analgesia requirements, or postoperative complications. However, the early group had significantly more blood loss, more operating time, and shorter hospital stay. Conclusion: Early laparoscopic cholecystectomy within 72 hours of onset of symptoms has both medical as well as socioeconomic benefits and should be the preferred approach for patients managed by surgeons with adequate experience in laparoscopic cholecystectomy. PMID:24020050

  7. The probability of evolutionary rescue: towards a quantitative comparison between theory and evolution experiments.

    PubMed

    Martin, Guillaume; Aguilée, Robin; Ramsayer, Johan; Kaltz, Oliver; Ronce, Ophélie

    2013-01-19

    Evolutionary rescue occurs when a population genetically adapts to a new stressful environment that would otherwise cause its extinction. Forecasting the probability of persistence under stress, including emergence of drug resistance as a special case of interest, requires experimentally validated quantitative predictions. Here, we propose general analytical predictions, based on diffusion approximations, for the probability of evolutionary rescue. We assume a narrow genetic basis for adaptation to stress, as is often the case for drug resistance. First, we extend the rescue model of Orr & Unckless (Am. Nat. 2008 172, 160-169) to a broader demographic and genetic context, allowing the model to apply to empirical systems with variation among mutation effects on demography, overlapping generations and bottlenecks, all common features of microbial populations. Second, we confront our predictions of rescue probability with two datasets from experiments with Saccharomyces cerevisiae (yeast) and Pseudomonas fluorescens (bacterium). The tests show the qualitative agreement between the model and observed patterns, and illustrate how biologically relevant quantities, such as the per capita rate of rescue, can be estimated from fits of empirical data. Finally, we use the results of the model to suggest further, more quantitative, tests of evolutionary rescue theory.

  8. Lower hybrid current drive experiments on Alcator C-Mod: Comparison with theory and simulationa)

    NASA Astrophysics Data System (ADS)

    Bonoli, P. T.; Ko, J.; Parker, R.; Schmidt, A. E.; Wallace, G.; Wright, J. C.; Fiore, C. L.; Hubbard, A. E.; Irby, J.; Marmar, E.; Porkolab, M.; Terry, D.; Wolfe, S. M.; Wukitch, S. J.; Alcator C-Mod Team; Wilson, J. R.; Scott, S.; Valeo, E.; Phillips, C. K.; Harvey, R. W.

    2008-05-01

    Lower hybrid (LH) current drive experiments have been carried out on the Alcator C-Mod tokamak [I. H. Hutchinson et al., Phys. Plasmas 1, 1511 (1994)] using a radio-frequency system at 4.6GHz. Up to 900kW of LH power has been coupled and driven LH currents have been inferred from magnetic measurements by extrapolating to zero loop voltage, yielding an efficiency of neILHR0/PLH≈2.5±0.2×1019(A/W/m2). We have simulated the LH current drive in these discharges using the combined ray tracing/three-dimensional (r,v⊥,v∥) Fokker-Planck code GENRAY-CQL3D (R. W. Harvey and M. McCoy, in Proceedings of the IAEA Technical Committee Meeting on Simulation and Modeling of Thermonuclear Plasmas, Montreal, Canada, 1992) and found similar current drive efficiencies. The simulated profiles of current density from CQL3D, including both ohmic plus LH drive have been found to be in good agreement with the measured current density from a motional Stark effect diagnostic. Measurements of nonthermal x-ray emission confirm the presence of a significant fast electron population and the three-dimensional (r,v⊥,v∥) electron distribution function from CQL3D has been used in a synthetic diagnostic code to simulate the measured hard x-ray data.

  9. Is Best-Worst Scaling Suitable for Health State Valuation? A Comparison with Discrete Choice Experiments.

    PubMed

    Krucien, Nicolas; Watson, Verity; Ryan, Mandy

    2016-12-04

    Health utility indices (HUIs) are widely used in economic evaluation. The best-worst scaling (BWS) method is being used to value dimensions of HUIs. However, little is known about the properties of this method. This paper investigates the validity of the BWS method to develop HUI, comparing it to another ordinal valuation method, the discrete choice experiment (DCE). Using a parametric approach, we find a low level of concordance between the two methods, with evidence of preference reversals. BWS responses are subject to decision biases, with significant effects on individuals' preferences. Non parametric tests indicate that BWS data has lower stability, monotonicity and continuity compared to DCE data, suggesting that the BWS provides lower quality data. As a consequence, for both theoretical and technical reasons, practitioners should be cautious both about using the BWS method to measure health-related preferences, and using HUI based on BWS data. Given existing evidence, it seems that the DCE method is a better method, at least because its limitations (and measurement properties) have been extensively researched. Copyright © 2016 John Wiley & Sons, Ltd.

  10. Electron attachment to SF6 under well defined conditions: comparison of statistical modeling results to experiments

    NASA Astrophysics Data System (ADS)

    Miller, T. M.; Viggiano, A. A.; Troe, J.

    2008-05-01

    Experiments were carried out using a flowing-afterglow Langmuir-probe apparatus to measure rate constants for electron attachment to SF6 and thermal detachment from SF6-. In a recent series of papers, these results were combined with new and existing data on nondissociative and dissociative attachment to SF6 and compared to statistical modeling of the various processes involved in the stabilization of the ionic products of attachment. This paper gives a summary of those findings. The major conclusions are: (a) only the ground electronic state of SF6- needs to be invoked to explain available data; (b) the electron affinity of SF6 is higher than previously thought, namely, EA(SF6) = 1.20 (± 0.05) eV; (c) the endothermicity of the dissociative electron attachment reaction that yields SF5- is 0.41 eV (± 0.05) eV at 0 K; (d) combining these two numbers gives the bond energy D0o(F—SF5-) = 1.61 (± 0.05) eV.

  11. Detailed comparison of simulations, experiments, and theory of sub-cyclotron Alfven eigenmodes in NSTX

    NASA Astrophysics Data System (ADS)

    Lestz, Jeff; Belova, Elena; Gorelenkov, Nikolai; Tang, Shawn; Crocker, Neal

    2016-10-01

    High frequency compressional (CAE) and global (GAE) Alfvén eigenmodes are often driven unstable by super-Alfvénic beam ions in NSTX, and have been linked to anomalous electron temperature profile flattening at high beam power [D. Stutman, PRL 2009]. A large set of 3D MHD- δf hybrid simulations show that GAE are ubiquitous at beam energies Vb /VA > 2.5 , while CAE are not excited until Vb /VA > 4 . The frequency of the most unstable GAE changes significantly with the normalized beam energy, consistent with trends described by its dispersion and resonance condition. These simulation results are analyzed and compared with a new, extensive experimental survey of NSTX discharges, as well as analytic studies. Interestingly, simulations find no case where counter-propagating CAE are more unstable than co-CAE, whereas experiments routinely observe both co- and counter-CAE. Moreover, simulations find co-GAE to be very unstable for beams peaked around λ <= 0.5 , yet these modes have not yet been thoroughly investigated experimentally. Preliminary predictions are also made for the CAE/GAE instability in ITER-like plasmas, which are expected to operate near similar values of Vb /VA as those studied for NSTX. This work supported by DOE contracts DE-AC02-09CH11466 and DE-SC0011810.

  12. Comparison of abuse experiences of rural and urban African American women during perinatal period.

    PubMed

    Bhandari, Shreya; Bullock, Linda F C; Richardson, Jeanita W; Kimeto, Pamela; Campbell, Jacquelyn C; Sharps, Phyllis W

    2015-07-01

    A subsample of 12 African American women (6 urban and 6 rural) were selected from a larger longitudinal, randomized control trial, Domestic Violence Enhanced Home Visitation (DOVE-R01 900903 National Institute of Nursing Research [NINR]/National Institutes of Health [NIH]). All African American women were chosen to control for any racial- and/or race-related cultural differences that may exist among women across geographical areas. The experiences of abuse during the perinatal period are drawn from in-depth interviews conducted at five points in time during pregnancy and the post-partum period. The analysis describes three major themes that highlight the similarities and differences among rural and urban women. The main themes found were (1) types of abuse, (2) location of abuse, and (3) response to abuse. In addition, two sub-themes (a) defiance and compliance and (b) role of children were also identified. Implications for universal screening for women of reproductive age, safer gun laws, and the need for further research are discussed.

  13. Growth of sinuous waves on thin liquid sheets: Comparison of predictions with experiments

    NASA Astrophysics Data System (ADS)

    Majumdar, Nayanika; Tirumkudulu, Mahesh S.

    2016-05-01

    A recent theory [M. S. Tirumkudulu and M. Paramati, "Stability of a moving radial liquid sheet: Time dependent equations," Phys. Fluids 25(10), 102-107 (2013)] has shown that a radially expanding liquid sheet is unstable to sinuous wave disturbances due to the thinning of the liquid sheet while ignoring the presence of a surrounding gas phase. In this work, we compare the predictions of the aforementioned theory with the measurements of Crapper et al. ["Large amplitude Kelvin-Helmholtz waves on thin liquid sheets," Proc. R. Soc. London, Ser. A 342(1629), 209-224 (1975)] who measured the amplitude and spatial growth rates of sinuous waves induced in radially expanding liquid sheets produced by fan spray nozzles. The predicted growth rates are remarkably close to the measurements over a range of forcing frequencies and amplitudes even though the experiments were performed in the presence of a surrounding gas phase. This is in contrast to large discrepancies observed by Crapper et al. when the same measurements were compared with the predictions of a spatial stability analysis for a moving liquid sheet that accounts for the inertia of the surrounding gas phase but ignores the thickness variation of the sheet.

  14. Preparing beginning reading teachers: An experimental comparison of initial early literacy field experiences.

    PubMed

    Al Otaiba, Stephanie; Lake, Vickie E; Greulich, Luana; Folsom, Jessica S; Guidry, Lisa

    2012-01-01

    This randomized-control trial examined the learning of preservice teachers taking an initial Early Literacy course in an early childhood education program and of the kindergarten or first grade students they tutored in their field experience. Preservice teachers were randomly assigned to one of two tutoring programs: Book Buddies and Tutor Assisted Intensive Learning Strategies (TAILS), which provided identical meaning-focused instruction (shared book reading), but differed in the presentation of code-focused skills. TAILS used explicit, scripted lessons, and the Book Buddies required that code-focused instruction take place during shared book reading. Our research goal was to understand which tutoring program would be most effective in improving knowledge about reading, lead to broad and deep language and preparedness of the novice preservice teachers, and yield the most successful student reading outcomes. Findings indicate that all pre-service teachers demonstrated similar gains in knowledge, but preservice teachers in the TAILS program demonstrated broader and deeper application of knowledge and higher self-ratings of preparedness to teach reading. Students in both conditions made similar comprehension gains, but students tutored with TAILS showed significantly stronger decoding gains.

  15. Wave Impact on a Wall: Comparison of Experiments with Similarity Solutions

    NASA Astrophysics Data System (ADS)

    Wang, A.; Duncan, J. H.; Lathrop, D. P.

    2014-11-01

    The impact of a steep water wave on a fixed partially submerged cube is studied with experiments and theory. The temporal evolution of the water surface profile upstream of the front face of the cube in its center plane is measured with a cinematic laser-induced fluorescence technique using frame rates up to 4,500 Hz. For a small range of cube positions, the surface profiles are found to form a nearly circular arc with upward curvature between the front face of the cube and a point just downstream of the wave crest. As the crest approaches the cube, the effective radius of this portion of the profile decreases rapidly. At the same time, the portion of the profile that is upstream of the crest approaches a straight line with a downward slope of about 15°. As the wave impact continues, the circular arc shrinks to zero radius with very high acceleration and a sudden transition to a high-speed vertical jet occurs. This flow singularity is modeled with a power-law scaling in time, which is used to create a time-independent system of equations of motion. The scaled governing equations are solved numerically and the similarly scaled measured free surface shapes, are favorably compared with the solutions. The support of the Office of Naval Research is gratefully acknowledged.

  16. Infrared absorption spectra, radiative efficiencies, and global warming potentials of perfluorocarbons: Comparison between experiment and theory

    NASA Astrophysics Data System (ADS)

    Bravo, IváN.; Aranda, Alfonso; Hurley, Michael D.; Marston, George; Nutt, David R.; Shine, Keith P.; Smith, Kevin; Wallington, Timothy J.

    2010-12-01

    Experimentally and theoretically determined infrared spectra are reported for a series of straight-chain perfluorocarbons: C2F6, C3F8, C4F10, C5F12, C6F14, and C8F18. Theoretical spectra were determined using both density functional (DFT) and ab initio methods. Radiative efficiencies (REs) were determined using the method of Pinnock et al. (1995) and combined with atmospheric lifetimes from the literature to determine global warming potentials (GWPs). Theoretically determined absorption cross sections were within 10% of experimentally determined values. Despite being much less computationally expensive, DFT calculations were generally found to perform better than ab initio methods. There is a strong wavenumber dependence of radiative forcing in the region of the fundamental C-F vibration, and small differences in wavelength between band positions determined by theory and experiment have a significant impact on the REs. We apply an empirical correction to the theoretical spectra and then test this correction on a number of branched chain and cyclic perfluoroalkanes. We then compute absorption cross sections, REs, and GWPs for an additional set of perfluoroalkenes.

  17. Comparison of Veteran experiences of low-cost, home-based diet and exercise interventions.

    PubMed

    Holtz, Bree; Krein, Sarah L; Bentley, Douglas R; Hughes, Maria E; Giardino, Nicholas D; Richardson, Caroline R

    2014-01-01

    Obesity is a significant health problem among Veterans who receive care from the Department of Veterans Affairs, as it is for so many other Americans. Veterans from Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) experience a myriad of chronic conditions, which can make it difficult to maintain a physically active lifestyle. This pilot study tested the feasibility and user satisfaction with three low-cost, home-based diet and exercise programs, as well as point-of-decision prompts among these Veterans. The three programs target mechanisms that have been shown to improve healthy behavior change, including (1) online mediated social support, (2) objective monitoring of physical activity, and (3) structured high-intensity workouts. This was a randomized crossover trial; each participant used two of the three programs, and all used the point-of-decision prompts. Our qualitative results identified five overall themes related to social support, objective monitoring, structured activity, awareness and understanding, and the point-of-decision prompts. In general, participants were satisfied with and lost weight with each of the interventions. This study demonstrated that these low-cost interventions could be successful with the OIF/OEF Veteran population. A larger and longer study is planned to further investigate the effectiveness of these interventions.

  18. Kinetic simulation of direct-drive capsule implosions and its comparison with experiments and radiation hydrodynamic simulation

    NASA Astrophysics Data System (ADS)

    Kwan, Thomas; Le, Ari; Schmitt, Mark; Herrmann, Hans; Batha, Steve

    2015-11-01

    We have carried out simulations of direct-drive capsule implosion experiments conducted on Omega laser facility at the Laboratory of Laser energetics of the University of Rochester. The capsules had a glass shell (SiO2) with D, T, He-3 fills at various proportions. One-dimensional radiation hydrodynamic calculations and kinetic particle/hybrid simulations with LSP were carried out for the post-shot analysis to compare neutron yield, yield ratio, and shell convergence in assessing the effects of plasma kinetic effects. The LSP simulations were initiated with the output from the rad-hydro simulations at the end of the laser-drive. The electrons are treated as a fluid while all the ion species by the kinetic PIC technique. Our LSP simulations clearly showed species separation between the deuterons, tritons and He-3 during the implosion but significantly less after the compression. The neutron yield, gamma bang-time and -width from the LSP simulations compared favorably with experiments. Detail comparison among the kinetic simulations, rad-hydro simulations, and experimental results will be presented. Work performed under the auspices of the US Department of Energy by Los Alamos National Laboratory under Contract No. W-7405-ENG-36.

  19. Comparison of numerical simulations to experiments for atomization in a jet nebulizer.

    PubMed

    Lelong, Nicolas; Vecellio, Laurent; Sommer de Gélicourt, Yann; Tanguy, Christian; Diot, Patrice; Junqua-Moullet, Alexandra

    2013-01-01

    The development of jet nebulizers for medical purposes is an important challenge of aerosol therapy. The performance of a nebulizer is characterized by its output rate of droplets with a diameter under 5 µm. However the optimization of this parameter through experiments has reached a plateau. The purpose of this study is to design a numerical model simulating the nebulization process and to compare it with experimental data. Such a model could provide a better understanding of the atomization process and the parameters influencing the nebulizer output. A model based on the Updraft nebulizer (Hudson) was designed with ANSYS Workbench. Boundary conditions were set with experimental data then transient 3D calculations were run on a 4 µm mesh with ANSYS Fluent. Two air flow rate (2 L/min and 8 L/min, limits of the operating range) were considered to account for different turbulence regimes. Numerical and experimental results were compared according to phenomenology and droplet size. The behavior of the liquid was compared to images acquired through shadowgraphy with a CCD Camera. Three experimental methods, laser diffractometry, phase Doppler anemometry (PDA) and shadowgraphy were used to characterize the droplet size distributions. Camera images showed similar patterns as numerical results. Droplet sizes obtained numerically are overestimated in relation to PDA and diffractometry, which only consider spherical droplets. However, at both flow rates, size distributions extracted from numerical image processing were similar to distributions obtained from shadowgraphy image processing. The simulation then provides a good understanding and prediction of the phenomena involved in the fragmentation of droplets over 10 µm. The laws of dynamics apply to droplets down to 1 µm, so we can assume the continuity of the distribution and extrapolate the results for droplets between 1 and 10 µm. So, this model could help predicting nebulizer output with defined geometrical and

  20. Molecular-dynamics simulation of model polymer nanocomposite rheology and comparison with experiment

    NASA Astrophysics Data System (ADS)

    Kairn, T.; Daivis, P. J.; Ivanov, I.; Bhattacharya, S. N.

    2005-11-01

    The shear-rate dependence of viscosity is studied for model polymer melts containing various concentrations of spherical filler particles by molecular-dynamics simulations, and the results are compared with the experimental results for calcium-carbonate-filled polypropylene. Although there are some significant differences in scale between the simulated model polymer composite and the system used in the experiments, some important qualitative similarities in shear behavior are observed. The trends in the steady-state shear viscosities of the simulated polymer-filler system agree with those seen in the experimental results; shear viscosities, zero-shear viscosities, and the rate of shear thinning are all seen to increase with filler content in both the experimental and simulated systems. We observe a significant difference between the filler volume fraction dependence of the zero-shear viscosity of the simulated system and that of the experimental system that can be attributed to a large difference in the ratio of the filler particle radius to the radius of gyration of the polymer molecules. In the simulated system, the filler particles are so small that they only have a weak effect on the viscosity of the composite at low filler volume fraction, but in the experimental system, the viscosity of the composite increases rapidly with increasing filler volume fraction. Our results indicate that there exists a value of the ratio of the filler particle radius to the polymer radius of gyration such that the zero-shear-rate viscosity of the composite becomes approximately independent of the filler particle volume fraction.

  1. A biomechanical comparison of composite femurs and cadaver femurs used in experiments on operated hip fractures.

    PubMed

    Basso, Trude; Klaksvik, Jomar; Syversen, Unni; Foss, Olav A

    2014-12-18

    Fourth generation composite femurs (4GCFs, models #3406 and #3403) simulate femurs of males <80 years with good bone quality. Since most hip fractures occur in old women with fragile bones, concern is raised regarding the use of standard 4GCFs in biomechanical experiments. In this study the stability of hip fracture fixations in 4GCFs was compared to human cadaver femurs (HCFs) selected to represent patients with hip fractures. Ten 4GCFs (Sawbones, Pacific Research Laboratories, Inc., Vashon, WA, USA) were compared to 24 HCFs from seven females and five males >60 years. Proximal femur anthropometric measurements were noted. Strain gauge rosettes were attached and femurs were mounted in a hip simulator applying a combined subject-specific axial load and torque. Baseline measurements of resistance to deformation were recorded. Standardized femoral neck fractures were surgically stabilized before the constructs were subjected to 20,000 load-cycles. An optical motion tracking system measured relative movements. Median (95% CI) head fragment migration was 0.8mm (0.4 to 1.1) in the 4GCF group versus 2.2mm (1.5 to 4.6) in the cadaver group (p=0.001). This difference in fracture stability could not be explained by observed differences in femoral anthropometry or potential overloading of 4GCFs. 4GCFs failed with fracture-patterns different from those observed in cadavers. To conclude, standard 4GCFs provide unrealistically stable bone-implant constructs and fail with fractures not observed in cadavers. Until a validated osteopenic or osteoporotic composite femur model is provided, standard 4GCFs should only be used when representing the biomechanical properties of young healthy femurs.

  2. Comparison of calculations with the BUSCA code against the LACE-Espana aerosol decontamination experiments

    SciTech Connect

    Bellemare, L.; Kissane, M.P.; Cadarache, C.E.

    1995-12-31

    The decontamination of a flow containing aerosols and soluble vapours when it passes through a water pool is often very efficient. This is an important consideration in nuclear reactor safety analysis: in the event of a severe loss-of-coolant accident, quantities of water could remain in the coolant system between the core, releasing radioactive vapours and aerosols, and the breach to the containment or auxiliary building (e.g. in the pressurizer or steam generator secondary side). Mechanistic computer codes such as BUSCA, Ramsdale et al (1993), have been developed to predict decontamination in water pools by modelling the formation of bubbles, bubble behaviour and the thermal hydraulics and aerosol physics inside bubbles. The experimental programme LACE-Espana, Marcos et al (1994), generated data on aerosol decontamination in a water pool. A steam-nitrogen mixture loaded with caesium iodide particles was injected into a part-filled tank 2.5m below the water surface. The gas injection rate and the aerosol distribution were varied over eleven tests. The work presented here concerns the interpretation of the LACE-Espana tests using the BUSCA code. It is seen that despite taking into account aerosol losses in the apparatus before the pool, the calculations generally underpredict, often significantly, the experimentally observed decontamination. This result is in qualitative agreement with an earlier study, Calvo and Alonso (1994), though significantly different input data were used in those calculations and higher decontamination was predicted. The calculation-experiment difference is explained in part by the approximation of treating the aerosol entering the pool as lognormal, a limitation of the code. Looking for other explanations, the modelling of jet impaction deposition is examined since this is by far the dominant decontamination mechanism in the calculations.

  3. Cross-national comparison of capitation funding: the American, British and Dutch experience.

    PubMed

    Persaud, D; Narine, L

    1999-05-01

    In this paper we review the performance of the capitation payment systems of three countries--the Adjusted Average Per Capita Cost (AAPCC) system used in the United States to reimburse Health Maintenance Organizations (HMOs) for insuring Medicare recipients, a somewhat similar system in the Netherlands which reimburses third-party payers for insuring the entire population and a weighted system utilized in Britain for regional funding. Our review revealed significant problems with the current version of the AAPCC formula as there is evidence of the biased selection of beneficiaries and actual losses to Medicare through its use. Furthermore, several studies show that the demographic adjusters utilized in the AAPCC formula are extremely poor predictors of future healthcare utilization relative to the potential of direct and indirect health status measures. The Dutch experience with capitated funding has been similar to that of the United States. While Dutch researchers have built on the work of their American counterparts they acknowledge that further work is needed before a fully functional system is implemented. Britain's weighted system has fulfilled its original mandate to redistribute healthcare resources based on population need but recent changes giving increased influence to age weighting could reverse some of these gains. A number of proposed improvements to these risk adjustment problems were reviewed including the development of diagnostic cost groups, the coexisting hierarchical conditions model and the use of community-rated high-risk pooling. The findings from this study can help others narrow the alternatives they need to consider when thinking of introducing capitation funding or refining already existing systems.

  4. Bacterial Chemotaxis in Porous Media: Theory Derivation and Comparison with Experiments

    NASA Astrophysics Data System (ADS)

    Valdés-Parada, Francisco J.; Porter, Mark L.; Wood, Brian D.

    2010-12-01

    Chemotaxis is the movement of organisms toward or away from the concentration gradient of a chemical species. Microbial chemotaxis has been shown to significantly increase contaminant degradation in subsurface environments with respect to traditional methods such as pump-and-treat. This type of transport phenomena often involves diffusion and convection along several scales. In this work we use the method of volume averaging to upscale the governing equations for in situ bioremediation by bacterial chemotaxis. The results are effective medium mass balance equations for both the bacteria and the chemical attractant. These equations are expressed in terms of average transport coefficients, which can be computed from the solution of the associated closure problems. For the bacteria, we introduce a total motility tensor and a total velocity vector, which are dependent upon the porous medium geometry, the fluid flow and the macroscale concentration and flux of the attractant. An attractive feature of this approach is that the transport coefficients can be computed a priori from performing experiments since they do not involve the use of adjustable coefficients. In addition, the necessary scaling laws, in terms of length-scale constraints and assumptions, which bound the applicability of the model are explicitly stated. The model was validated by comparing the transverse bacterial concentration with previously reported experimental measurements for E. coli HCB1 in a T-sensor. The results exhibited a maximum deviation of approximately 10% (in terms of the mean absolute error) with experimental data for several flow rates. These results suggest that the predictive multiscale approach presented here is reliable for modeling chemotaxis in porous media.

  5. Comparison of prototype and laboratory experiments on MOMA GCMS: results from the AMASE11 campaign.

    PubMed

    Siljeström, Sandra; Freissinet, Caroline; Goesmann, Fred; Steininger, Harald; Goetz, Walter; Steele, Andrew; Amundsen, Hans

    2014-09-01

    The characterization of any organic molecules on Mars is a top-priority objective for the ExoMars European Space Agency-Russian Federal Space Agency joint mission. The main instrument for organic analysis on the ExoMars rover is the Mars Organic Molecule Analyzer (MOMA). In preparation for the upcoming mission in 2018, different Mars analog samples are studied with MOMA and include samples collected during the Arctic Mars Analog Svalbard Expedition (AMASE) to Svalbard, Norway. In this paper, we present results obtained from two different Mars analog sites visited during AMASE11, Colletthøgda and Botniahalvøya. Measurements were performed on the samples during AMASE11 with a MOMA gas chromatograph (GC) prototype connected to a commercial mass spectrometer (MS) and later in home institutions with commercial pyrolysis-GCMS instruments. In addition, derivatization experiments were performed on the samples during AMASE11 and in the laboratory. Three different samples were studied from the Colletthøgda that included one evaporite and two carbonate-bearing samples. Only a single sample was studied from the Botniahalvøya site, a weathered basalt covered by a shiny surface consisting of manganese and iron oxides. Organic molecules were detected in all four samples and included aromatics, long-chained hydrocarbons, amino acids, nucleobases, sugars, and carboxylic acids. Both pyrolysis and derivatization indicated the presence of extinct biota by the detection of carboxylic acids in the samples from Colletthøgda, while the presence of amino acids, nucleobases, carboxylic acids, and sugars indicated an active biota in the sample from Botniahalvøya. The results obtained with the prototype flight model in the field coupled with repeat measurements with commercial instruments within the laboratory were reassuringly similar. This demonstrates the performance of the MOMA instrument and validates that the instrument will aid researchers in their efforts to answer fundamental

  6. Simulating thermal explosion of RDX-based explosives: Model comparison with experiment

    SciTech Connect

    Yoh, J J; McClelland, M A; Maienschein, J L; Wardell, J F; Tarver, C M

    2004-10-11

    We compare two-dimensional model results with measurements for the thermal, chemical and mechanical behavior in a thermal explosion experiment. Confined high explosives are heated at a rate of 1 C per hour until an explosion is observed. The heating, ignition, and deflagration phases are modeled using an Arbitrarily Lagrangian-Eulerian code (ALE3D) that can handle a wide range of time scales that vary from a structural to a dynamic hydro time scale. During the pre-ignition phase, quasi-static mechanics and diffusive thermal transfer from a heat source to the HE are coupled with the finite chemical reactions that include both endothermic and exothermic processes. Once the HE ignites, a hydro dynamic calculation is performed as a burn front propagates through the HE. Two RDX-based explosives, C-4 and PBXN-109, are considered, whose chemical-thermal-mechanical models are constructed based on measurements of thermal and mechanical properties along with small scale thermal explosion measurements. The simulated dynamic response of HE confinement during the explosive phase is compared to measurements in large scale thermal explosion tests. The explosion temperatures for both HE's are predicted to within 5 C. Calculated and measured wall strains provide an indication of vessel pressurization during the heating phase and violence during the explosive phase. During the heating phase, simulated wall strains provide only an approximate representation of measured values indicating a better numerical treatment is needed to provide accurate results. The results also show that more numerical accuracy is needed for vessels with lesser confinement strength. For PBXN-109, the measured wall strains during the explosion are well represented by the ALE3D calculations.

  7. Comparison of Numerical Simulations to Experiments for Atomization in a Jet Nebulizer

    PubMed Central

    Lelong, Nicolas; Vecellio, Laurent; Sommer de Gélicourt, Yann; Tanguy, Christian; Diot, Patrice; Junqua-Moullet, Alexandra

    2013-01-01

    The development of jet nebulizers for medical purposes is an important challenge of aerosol therapy. The performance of a nebulizer is characterized by its output rate of droplets with a diameter under 5 µm. However the optimization of this parameter through experiments has reached a plateau. The purpose of this study is to design a numerical model simulating the nebulization process and to compare it with experimental data. Such a model could provide a better understanding of the atomization process and the parameters influencing the nebulizer output. A model based on the Updraft nebulizer (Hudson) was designed with ANSYS Workbench. Boundary conditions were set with experimental data then transient 3D calculations were run on a 4 µm mesh with ANSYS Fluent. Two air flow rate (2 L/min and 8 L/min, limits of the operating range) were considered to account for different turbulence regimes. Numerical and experimental results were compared according to phenomenology and droplet size. The behavior of the liquid was compared to images acquired through shadowgraphy with a CCD Camera. Three experimental methods, laser diffractometry, phase Doppler anemometry (PDA) and shadowgraphy were used to characterize the droplet size distributions. Camera images showed similar patterns as numerical results. Droplet sizes obtained numerically are overestimated in relation to PDA and diffractometry, which only consider spherical droplets. However, at both flow rates, size distributions extracted from numerical image processing were similar to distributions obtained from shadowgraphy image processing. The simulation then provides a good understanding and prediction of the phenomena involved in the fragmentation of droplets over 10 µm. The laws of dynamics apply to droplets down to 1 µm, so we can assume the continuity of the distribution and extrapolate the results for droplets between 1 and 10 µm. So, this model could help predicting nebulizer output with defined geometrical and

  8. Design of a Laboratory Hall Thruster with Magnetically Shielded Channel Walls, Phase III: Comparison of Theory with Experiment

    NASA Technical Reports Server (NTRS)

    Mikellides, Ioannis G.; Katz, Ira; Hofer, Richard R.; Goebel, Dan M.

    2012-01-01

    A proof-of-principle effort to demonstrate a technique by which erosion of the acceleration channel in Hall thrusters of the magnetic-layer type can be eliminated has been completed. The first principles of the technique, now known as "magnetic shielding," were derived based on the findings of numerical simulations in 2-D axisymmetric geometry. The simulations, in turn, guided the modification of an existing 6-kW laboratory Hall thruster. This magnetically shielded (MS) thruster was then built and tested. Because neither theory nor experiment alone can validate fully the first principles of the technique, the objective of the 2-yr effort was twofold: (1) to demonstrate in the laboratory that the erosion rates can be reduced by >order of magnitude, and (2) to demonstrate that the near-wall plasma properties can be altered according to the theoretical predictions. This paper concludes the demonstration of magnetic shielding by reporting on a wide range of comparisons between results from numerical simulations and laboratory diagnostics. Collectively, we find that the comparisons validate the theory. Near the walls of the MS thruster, theory and experiment agree: (1) the plasma potential has been sustained at values near the discharge voltage, and (2) the electron temperature has been lowered by at least 2.5-3 times compared to the unshielded (US) thruster. Also, based on carbon deposition measurements, the erosion rates at the inner and outer walls of the MS thruster are found to be lower by at least 2300 and 1875 times, respectively. Erosion was so low along these walls that the rates were below the resolution of the profilometer. Using a sputtering yield model with an energy threshold of 25 V, the simulations predict a reduction of 600 at the MS inner wall. At the outer wall ion energies are computed to be below 25 V, for which case we set the erosion to zero in the simulations. When a 50-V threshold is used the computed ion energies are below the threshold at both

  9. Mesoscopic models for DNA stretching under force: New results and comparison with experiments.

    PubMed

    Manghi, Manoel; Destainville, Nicolas; Palmeri, John

    2012-10-01

    Single-molecule experiments on double-stranded B-DNA stretching have revealed one or two structural transitions, when increasing the external force. They are characterized by a sudden increase of DNA contour length and a decrease of the bending rigidity. The nature and the critical forces of these transitions depend on DNA base sequence, loading rate, salt conditions and temperature. It has been proposed that the first transition, at forces of 60-80 pN, is a transition from B to S-DNA, viewed as a stretched duplex DNA, while the second one, at stronger forces, is a strand peeling resulting in single-stranded DNAs (ssDNA), similar to thermal denaturation. But due to experimental conditions these two transitions can overlap, for instance for poly(dA-dT). In an attempt to propose a coherent picture compatible with this variety of experimental observations, we derive an analytical formula using a coupled discrete worm-like chain-Ising model. Our model takes into account bending rigidity, discreteness of the chain, linear and non-linear (for ssDNA) bond stretching. In the limit of zero force, this model simplifies into a coupled model already developed by us for studying thermal DNA melting, establishing a connection with previous fitting parameter values for denaturation profiles. Our results are summarized as follows: i) ssDNA is fitted, using an analytical formula, over a nano-Newton range with only three free parameters, the contour length, the bending modulus and the monomer size; ii) a surprisingly good fit on this force range is possible only by choosing a monomer size of 0.2 nm, almost 4 times smaller than the ssDNA nucleobase length; iii) mesoscopic models are not able to fit B to ssDNA (or S to ss) transitions; iv) an analytical formula for fitting B to S transitions is derived in the strong force approximation and for long DNAs, which is in excellent agreement with exact transfer matrix calculations; v) this formula fits perfectly well poly(dG-dC) and

  10. Lower Hybrid Current Drive Experiments on Alcator C-Mod: Comparison with Theory and Simulation

    NASA Astrophysics Data System (ADS)

    Bonoli, Paul

    2007-11-01

    Recently, lower hybrid current drive (LHCD) experiments have been carried out on Alcator C-Mod using an RF system consisting of 12 klystrons at 4.6 GHz, feeding a 4 x 22 waveguide array. Up to 900 kW of LH power has been coupled in the range1.6 <= n//<= 4), where n// is the parallel refractive index. Driven LH currents have been inferred from magnetic measurements by extrapolating to zero loop voltage, yielding an efficiency of n20ILHR/PLH 0.3 [1]. We have simulated the LH current drive in these discharges using the combined ray tracing / 3D (r, v, v//) Fokker Planck code GENRAY -- CQL3D [2] and found similar current drive efficiencies. Measurements of nonthermal x-ray emission and electron cyclotron emission (ECE) confirm the presence of a significant fast electron population that varies with waveguide phasing and plasma density. Studies are currently underway to investigate the role of fast electron diffusion and full-wave effects such as diffractional broadening in determining the spatial and velocity space structure of the nonthermal electrons. The 3D (r, v, v//) electron distribution function from CQL3D has been used in synthetic diagnostic codes to simulate the measured hard x-ray and ECE emissions. Fast electron diffusion times have been inferred from x-ray data by employing a radial diffusion operator in CQL3D and determining the fast electron diffusivities that are required to reproduce the experimentally observed profiles of hard x-ray emission. Finally, we have been performing full-wave LH field simulations using the massively parallel TORIC --LH solver [3] in order to assess spatial and spectral broadening of the incident wave front that can result from diffraction and wave focusing effects. [1] R. Parker, Bull. Am. Phys. Soc. 51, 20 (2006). [2] R.W. Harvey and M. McCoy, ``The CQL3D Fokker Planck Code,'' Proc. IAEA Tech. Comm. Meeting on Simulation and Modeling of Thermonuclear Plasmas, Montreal, Canada, 1992. [3] J. C. Wright et al., Nucl. Fusion 45

  11. Cracking-induced permeability alterations in geomaterials: A comparison of experiments and computational predictions

    NASA Astrophysics Data System (ADS)

    Massart, T. J.; Selvadurai, A. P.

    2012-12-01

    Poroelasticity is the most widely used geomechanics model for examining critical problems of current importance to environmental geosciences. A fundamental assumption in poroelasticity is that the material properties such as the deformability or the permeability remain unchanged during the coupled interaction between the porous skeleton and the saturating fluid. However, it is known that the porous fabric can experience micro-mechanical damage due to the application of stresses or to the transport of reactive fluids that can lead to changes in the deformability, strength and permeability characteristics. By far the most common action that can alter the properties of the porous geomaterials is the micromechanical damage resulting from the application of stresses. Experimental results conducted on granite and limestone indicate variations in permeability with an increase in deviatoric stress states well below the peak failure loads. This can in turn drastically influence the duration of transient processes involving pore fluid pressure dissipation. In this research, we present a multi-scale computational approach for investigating permeability evolution in a heterogeneous porous quasi-brittle geomaterial. Three-dimensional representative volume elements are produced to replicate the geomaterial with a heterogeneous fabric by means of different techniques (Voronoi tessellation, ...). Fine scale constitutive laws are used to model the progressive mechanical degradation under stress at the level of individual cracks. Interfacial cohesive laws are used for this purpose, which incorporate measurable mechanical parameters such as tensile strength, cohesion and related fracture energies. A fine-scale coupling is then used to translate the local crack features into evolving local permeability quantities, and a versatile computational homogenization technique is developed to upscale mechanical and transport properties corresponding to heterogeneous microstructures towards

  12. Simulation studies as designed experiments: the comparison of penalized regression models in the "large p, small n" setting.

    PubMed

    Chaibub Neto, Elias; Bare, J Christopher; Margolin, Adam A

    2014-01-01

    New algorithms are continuously proposed in computational biology. Performance evaluation of novel methods is important in practice. Nonetheless, the field experiences a lack of rigorous methodology aimed to systematically and objectively evaluate competing approaches. Simulation studies are frequently used to show that a particular method outperforms another. Often times, however, simulation studies are not well designed, and it is hard to characterize the particular conditions under which different methods perform better. In this paper we propose the adoption of well established techniques in the design of computer and physical experiments for developing effective simulation studies. By following best practices in planning of experiments we are better able to understand the strengths and weaknesses of competing algorithms leading to more informed decisions about which method to use for a particular task. We illustrate the application of our proposed simulation framework with a detailed comparison of the ridge-regression, lasso and elastic-net algorithms in a large scale study investigating the effects on predictive performance of sample size, number of features, true model sparsity, signal-to-noise ratio, and feature correlation, in situations where the number of covariates is usually much larger than sample size. Analysis of data sets containing tens of thousands of features but only a few hundred samples is nowadays routine in computational biology, where "omics" features such as gene expression, copy number variation and sequence data are frequently used in the predictive modeling of complex phenotypes such as anticancer drug response. The penalized regression approaches investigated in this study are popular choices in this setting and our simulations corroborate well established results concerning the conditions under which each one of these methods is expected to perform best while providing several novel insights.

  13. The initial stages of explosive volcanic eruptions: insights gained from comparisons between laboratory experiments and numerical models

    NASA Astrophysics Data System (ADS)

    Clarke, A. B.; de'Michieli Vitturi, M.; Chojnicki, K. N.; Phillips, J. C.

    2011-12-01

    Explosive volcanic eruptions begin with fragmentation, accompanied by formation of a leading pressure or shock wave and high acceleration of a gas-pyroclast mixture behind that wave. Characterizing and quantifying the details of the initial phases is critical in part because these processes control vent velocity and mass flux, which in turn partially control whether or not an eruption column buoyantly rises or collapses to form pyroclastic density currents. Parameters of particular interest are gas and particle acceleration rate, the degree of coupling between pyroclast and gas phases, particle concentration, shock wave characteristics (which can be measured in the field and interpreted to infer pre-eruption, sub-surface conditions), and characteristics of the rarefaction wave (because its propagation limits the propagation of the fragmentation front). To study these processes, we compared 1D shock tube experiments and equivalent 1D numerical model runs for a range of conditions: initial pressure ratios of 5 to 100, initial particle concentrations of about 40 vol% (air as ambient), and particle sizes of 4 μm to 150 μm. Key parameters of comparison are shock wave strength and velocity and particle flow-front velocity. Rarefaction wave speed and gas velocity behind the shock were calculated using the model, but are difficult to measure in the laboratory and therefore are not an integral part of our study at this time. In general, the experiments and calculations are in reasonable agreement in terms of shock wave characteristics. However, the model over predicts particle velocities by an order of magnitude relative to laboratory measurements. This discrepancy is significant because, as stated above, initial particle velocity is of critical interest to volcanologists when making predictions about plume behavior. We propose two explanations for the difference between calculated and measured particle velocities. 1) Overestimation of the drag coefficient which couples

  14. Arsenic in hydrothermal apatite: Oxidation state, mechanism of uptake, and comparison between experiments and nature

    NASA Astrophysics Data System (ADS)

    Liu, Weihua; Mei, Yuan; Etschmann, Barbara; Brugger, Joël; Pearce, Mark; Ryan, Chris G.; Borg, Stacey; Wykes, Jeremey; Kappen, Peter; Paterson, David; Boesenberg, Ulrike; Garrevoet, Jan; Moorhead, Gareth; Falkenberg, Gerald

    2017-01-01

    Element substitution that occurs during fluid-rock interaction permits assessment of fluid composition and interaction conditions in ancient geological systems, and provides a way to fix contaminants from aqueous solutions. We conducted a series of hydrothermal mineral replacement experiments to determine whether a relationship can be established between arsenic (As) distribution in apatite and fluid chemistry. Calcite crystals were reacted with phosphate solutions spiked with As(V), As(III), and mixed As(III)/As(V) species at 250 °C and water-saturated pressure. Arsenic-bearing apatite rims formed in several hours, and within 48 h the calcite grains were fully replaced. X-ray Absorption Near-edge Spectroscopy (XANES) data show that As retained the trivalent oxidation state in the fully-reacted apatite grown from solutions containing only As(III). Extended X-ray Fine Spectroscopy (EXAFS) data reveal that these As(III) ions are surrounded by about three oxygen atoms at an Assbnd O bond length close to that of an arsenate group (AsO43-), indicating that they occupy tetrahedral phosphate sites. The three-coordinated As(III)-O3 structure, with three oxygen atoms and one lone electron pair around As(III), was confirmed by geometry optimization using ab initio molecular simulations. The micro-XANES imaging data show that apatite formed from solutions spiked with mixed As(III) and As(V) retained only As(V) after completion of the replacement reaction; in contrast, partially reacted samples revealed a complex distribution of As(V)/As(III) ratios, with As(V) concentrated in the center of the grain and As(III) towards the rim. Most natural apatites from the Ernest Henry iron oxide copper gold deposit, Australia, show predominantly As(V), but two grains retained some As(III) in their core. The As-anomalous amphibolite-facies gneiss from Binntal, Switzerland, only revealed As(V), despite the fact that these apatites in both cases formed under conditions where As(III) is

  15. Comparison of Calculated and Measured Neutron Fluence in Fuel/Cladding Irradiation Experiments in HFIR

    SciTech Connect

    Ellis, Ronald James

    2011-01-01

    A recently-designed thermal neutron irradiation facility has been used for a first series of irradiations of PWR fuel pellets in the high flux isotope reactor (HFIR) at Oak Ridge National Laboratory. Since June 2010, irradiations of PWR fuel pellets made of UN or UO{sub 2}, clad in SiC, have been ongoing in the outer small VXF sites in the beryllium reflector region of the HFIR, as seen in Fig. 1. HFIR is a versatile, 85 MW isotope production and test reactor with the capability and facilities for performing a wide variety of irradiation experiments. HFIR is a beryllium-reflected, light-water-cooled and -moderated, flux-trap type reactor that uses highly enriched (in {sup 235}U) uranium (HEU) as the fuel. The reactor core consists of a series of concentric annular regions, each about 2 ft (0.61 m) high. A 5-in. (12.70-cm)-diam hole, referred to as the flux trap, forms the center of the core. The fuel region is composed of two concentric fuel elements made up of many involute-shaped fuel plates: an inner element that contains 171 fuel plates, and an outer element that contains 369 fuel plates. The fuel plates are curved in the shape of an involute, which provides constant coolant channel width between plates. The fuel (U{sub 3}O{sub 8}-Al cermet) is nonuniformly distributed along the arc of the involute to minimize the radial peak-to-average power density ratio. A burnable poison (B{sub 4}C) is included in the inner fuel element primarily to reduce the negative reactivity requirements of the reactor control plates. A typical HEU core loading in HFIR is 9.4 kg of {sup 235}U and 2.8 g of {sup 10}B. The thermal neutron flux in the flux trap region can exceed 2.5 x 10{sup 15} n/cm{sup 2} {center_dot} s while the fast flux in this region exceeds 1 x 10{sup 15} n/cm{sup 2} {center_dot} s. The inner and outer fuel elements are in turn surrounded by a concentric ring of beryllium reflector approximately 1 ft (0.30 m) thick. The beryllium reflector consists of three regions

  16. Laboratory experiments for inter-comparison of three volume scattering meters to measure angular scattering properties of hydrosols.

    PubMed

    Harmel, T; Hieronymi, M; Slade, W; Röttgers, R; Roullier, F; Chami, M

    2016-01-25

    Measurements of the volume scattering function (VSF) of hydrosols is of primary importance to investigate the interaction of light with hydrosols and to further interpret in situ and remote sensing data of ocean color. In this paper, a laboratory inter-comparison experiment of three recently developed VSF meters that are able to measure the scattered light for a wide range of scattering angle at 515 nm wavelength is performed using phytoplankton cultures and mineral-like hydrosols. A rigorous measurement protocol was employed to ensure good quality data. In particular, the protocol enabled removing the influence of bacteria on the hydrosols within the sample. The differences in the VSF measurements between the instruments vary from 10 to 25% depending on the composition of the hydrosols. The analysis of the angular features of the VSF revealed a sharp increase of the VSF beyond the scattering angle of 150° for some phytoplankton species. Such behavior is observed for two of the three VSF meters, thus suggesting that it is not due to instrumental artifacts but more likely to phytoplankton optical properties themselves. Moreover, comparisons with currently used theoretical phase functions show that the models are not able to reproduce satisfactorily the directional patterns in the backscattering region. This study suggests that a better modelling of the VSF shape of phytoplankton at high scattering angles is required to correctly represent the angular shape of the VSF in the backscattering hemisphere. Tabulated values of the measured phase functions are provided for scattering angles from 0.1 to 175°.

  17. Simulations of inorganic-bioorganic interfaces to discover new materials: insights, comparisons to experiment, challenges, and opportunities.

    PubMed

    Heinz, Hendrik; Ramezani-Dakhel, Hadi

    2016-01-21

    Natural and man-made materials often rely on functional interfaces between inorganic and organic compounds. Examples include skeletal tissues and biominerals, drug delivery systems, catalysts, sensors, separation media, energy conversion devices, and polymer nanocomposites. Current laboratory techniques are limited to monitor and manipulate assembly on the 1 to 100 nm scale, time-consuming, and costly. Computational methods have become increasingly reliable to understand materials assembly and performance. This review explores the merit of simulations in comparison to experiment at the 1 to 100 nm scale, including connections to smaller length scales of quantum mechanics and larger length scales of coarse-grain models. First, current simulation methods, advances in the understanding of chemical bonding, in the development of force fields, and in the development of chemically realistic models are described. Then, the recognition mechanisms of biomolecules on nanostructured metals, semimetals, oxides, phosphates, carbonates, sulfides, and other inorganic materials are explained, including extensive comparisons between modeling and laboratory measurements. Depending on the substrate, the role of soft epitaxial binding mechanisms, ion pairing, hydrogen bonds, hydrophobic interactions, and conformation effects is described. Applications of the knowledge from simulation to predict binding of ligands and drug molecules to the inorganic surfaces, crystal growth and shape development, catalyst performance, as well as electrical properties at interfaces are examined. The quality of estimates from molecular dynamics and Monte Carlo simulations is validated in comparison to measurements and design rules described where available. The review further describes applications of simulation methods to polymer composite materials, surface modification of nanofillers, and interfacial interactions in building materials. The complexity of functional multiphase materials creates

  18. Comparison of silver, cesium, and strontium release predictions using PARFUME with results from the AGR-1 irradiation experiment

    NASA Astrophysics Data System (ADS)

    Collin, Blaise P.; Petti, David A.; Demkowicz, Paul A.; Maki, John T.

    2015-11-01

    The PARFUME (PARticle FUel ModEl) code was used to predict the release of fission products silver, cesium, and strontium from tristructural isotropic coated fuel particles and compacts during the first irradiation experiment (AGR-1) of the Advanced Gas Reactor Fuel Development and Qualification program. The PARFUME model for the AGR-1 experiment used the fuel compact volume average temperature for each of the 620 days of irradiation to calculate the release of silver, cesium, and strontium from a representative particle for a select number of AGR-1 compacts. Post-irradiation examination (PIE) measurements provided data on release of these fission products from fuel compacts and fuel particles, and retention of silver in the compacts outside of the silicon carbide (SiC) layer. PARFUME-predicted fractional release of silver, cesium, and strontium was determined and compared to the PIE measurements. For silver, comparisons show a trend of over-prediction at low burnup and under-prediction at high burnup. PARFUME has limitations in the modeling of the temporal and spatial distributions of the temperature and burnup across the compacts, which affects the accuracy of its predictions. Nevertheless, the comparisons on silver release lie in the same order of magnitude. Results show an overall over-prediction of the fractional release of cesium by PARFUME. For particles with failed SiC layers, the over-prediction is by a factor of up to 3, corresponding to a potential over-estimation of the diffusivity in uranium oxycarbide (UCO) by a factor of up to 250. For intact particles, whose release is much lower, the over-prediction is by a factor of up to 100, which could be attributed to an over-estimated diffusivity in SiC by about 40% on average. The release of strontium from intact particles is also over-predicted by PARFUME, which also points towards an over-estimated diffusivity of strontium in either SiC or UCO, or possibly both. The measured strontium fractional release

  19. Comparison of silver, cesium, and strontium release predictions using PARFUME with results from the AGR-1 irradiation experiment

    DOE PAGES

    Collin, Blaise P.; Petti, David A.; Demkowicz, Paul A.; ...

    2015-08-22

    The PARFUME (PARticle FUel ModEl) code was used to predict the release of fission products silver, cesium, and strontium from tristructural isotropic coated fuel particles and compacts during the first irradiation experiment (AGR-1) of the Advanced Gas Reactor Fuel Development and Qualification program. The PARFUME model for the AGR-1 experiment used the fuel compact volume average temperature for each of the 620 days of irradiation to calculate the release of silver, cesium, and strontium from a representative particle for a select number of AGR-1 compacts. Post-irradiation examination measurements provided data on release of these fission products from fuel compacts andmore » fuel particles, and retention of silver in the compacts outside of the silicon carbide (SiC) layer. PARFUME-predicted fractional release of silver, cesium, and strontium was determined and compared to the PIE measurements. For silver, comparisons show a trend of over-prediction at low burnup and under-prediction at high burnup. PARFUME has limitations in the modeling of the temporal and spatial distributions of the temperature and burnup across the compacts, which affects the accuracy of its predictions. Nevertheless, the comparisons on silver release lie in the same order of magnitude. Results show an overall over-prediction of the fractional release of cesium by PARFUME. For particles with failed SiC layers, the over-prediction is by a factor of up to 3, corresponding to a potential over-estimation of the diffusivity in uranium oxycarbide (UCO) by a factor of up to 250. For intact particles, whose release is much lower, the over-prediction is by a factor of up to 100, which could be attributed to an over-estimated diffusivity in SiC by about 40% on average. The release of strontium from intact particles is also over-predicted by PARFUME, which also points towards an over-estimated diffusivity of strontium in either SiC or UCO, or possibly both. The measured strontium fractional release

  20. Comparison of silver, cesium, and strontium release predictions using PARFUME with results from the AGR-1 irradiation experiment

    SciTech Connect

    Collin, Blaise P.; Petti, David A.; Demkowicz, Paul A.; Maki, John T.

    2015-08-22

    The PARFUME (PARticle FUel ModEl) code was used to predict the release of fission products silver, cesium, and strontium from tristructural isotropic coated fuel particles and compacts during the first irradiation experiment (AGR-1) of the Advanced Gas Reactor Fuel Development and Qualification program. The PARFUME model for the AGR-1 experiment used the fuel compact volume average temperature for each of the 620 days of irradiation to calculate the release of silver, cesium, and strontium from a representative particle for a select number of AGR-1 compacts. Post-irradiation examination measurements provided data on release of these fission products from fuel compacts and fuel particles, and retention of silver in the compacts outside of the silicon carbide (SiC) layer. PARFUME-predicted fractional release of silver, cesium, and strontium was determined and compared to the PIE measurements. For silver, comparisons show a trend of over-prediction at low burnup and under-prediction at high burnup. PARFUME has limitations in the modeling of the temporal and spatial distributions of the temperature and burnup across the compacts, which affects the accuracy of its predictions. Nevertheless, the comparisons on silver release lie in the same order of magnitude. Results show an overall over-prediction of the fractional release of cesium by PARFUME. For particles with failed SiC layers, the over-prediction is by a factor of up to 3, corresponding to a potential over-estimation of the diffusivity in uranium oxycarbide (UCO) by a factor of up to 250. For intact particles, whose release is much lower, the over-prediction is by a factor of up to 100, which could be attributed to an over-estimated diffusivity in SiC by about 40% on average. The release of strontium from intact particles is also over-predicted by PARFUME, which also points towards an over-estimated diffusivity of strontium in either SiC or UCO, or possibly both. The measured strontium fractional release from

  1. Comparison and modeling of effects of normal and reduced precipitation supply in field experiment with spring barley

    NASA Astrophysics Data System (ADS)

    Pohanková, Eva; Orság, Matěj; Fischer, Milan; Hlavinka, Petr

    2015-04-01

    This paper evaluates two-year (2013 and 2014) results of field experiments with spring barley (cultivar Bojos) under reduced precipitation supply. The field experiments were carried out at the experimental station in Domanínek (Czech Republic; 49°31,470'N, 16°14,400'E, altitude 530 m a.s.l.) and conducted by Institute of Agrosystems and bioclimatology at Mendel Univerzity in Brno in cooperation with Global Change Research Centre AS CR. The field experiments consisted of small plots in two variants and three repetitions. The first variant was uncovered the second was partially covered to exclude rain through out the whole vegetation season. For the partial covering of the plot, a material which transmits solar radiation and diverts rainwater away from the percentage coverage of the plots was used. In 2013, the covered area of the experimental plot was 30%, and in 2014, it was 70%. The main aim was to determine whether there are any differences in the spring barley's development, growth and yield in the uncovered and the partially covered plots, and a comparison of the results. Firstly, differences of key parameters (seasonal dynamics of the leaf area index and above ground biomass, soil water content, yield components and yields) compared; secondly, the results of the field experiments served as input data for the crop growth model DAISY. Subsequently, the crop growth model' ability to simulate crop growth and crop development which were affected by the drought stress was explored. The results were assessed using the following statistical indexes: root mean square error (RMSE) and mean bias error (MBE). This study was funded by project "Building up a multidisciplinary scientific team focused on drought" No. CZ.1.07/2.3.00/20.0248, NAZV-JPI - project supported by Czech National Agency of Agricultural Research No. QJ1310123 "Crop modelling as a tool for increasing the production potential and food security of the Czech Republic under Climate Change" and project LD

  2. Effects of upward and downward social comparison information on the efficacy of an appearance-based sun protection intervention: a randomized, controlled experiment.

    PubMed

    Mahler, Heike I M; Kulik, James A; Gerrard, Meg; Gibbons, Frederick X

    2010-12-01

    This experiment examined the impact of adding upward and/or downward social comparison information on the efficacy of an appearance-based sun protection intervention (UV photos and photoaging information). Southern California college students (N = 126) were randomly assigned to one of four conditions: control, intervention, intervention plus upward social comparison, intervention plus downward social comparison. The results demonstrated that all those who received the basic UV photo/photoaging intervention reported greater perceived susceptibility to photoaging (d = .74), less favorable tanning cognitions (d = .44), and greater intentions to sun protect (d = 1.32) relative to controls. Of more interest, while the basic intervention increased sun protective behavior during the subsequent 5 weeks relative to controls (d = .44), the addition of downward comparison information completely negated this benefit. Upward comparison information produced sun protection levels that were only slightly (and nonsignificantly) greater than in the basic intervention condition and, as such, does not appear to be a cost-effective addition. Possible mechanisms that may have reduced the benefits of upward comparison information and contributed to the undermining effects of downward comparison information are discussed.

  3. Choice of experimental venue matters in ecotoxicology studies: Comparison of a laboratory-based and an outdoor mesocosm experiment.

    PubMed

    Mikó, Zsanett; Ujszegi, János; Gál, Zoltán; Imrei, Zoltán; Hettyey, Attila

    2015-10-01

    The heavy application of pesticides and its potential effects on natural communities has attracted increasing attention to inadvertent impacts of these chemicals. Toxicologists conventionally use laboratory-based tests to assess lethal concentrations of pesticides. However, these tests often do not take into account indirect, interactive and long-term effects, and tend to ignore different rates of disintegration in the laboratory and under natural conditions. Our aim was to investigate the importance of the experimental venue for ecotoxicology tests. We reared tadpoles of the agile frog (Rana dalmatina) in the laboratory and in outdoor mesocosms and exposed them to three initial concentrations of a glyphosate-based herbicide (0, 2 and 6.5 mg a.e./L glyphosate), and to the presence or absence of caged predators (dragonfly larvae). The type of experimental venue had a large effect on the outcome: The herbicide was less lethal to tadpoles reared in outdoor mesocosms than in the laboratory. Further, while the herbicide had a negative effect on development time and on body mass in the laboratory, tadpoles exposed to the herbicide in mesocosms were larger at metamorphosis and developed faster in comparison to those reared in the absence of the herbicide. The effect of the herbicide on morphological traits of tadpoles also differed between the two venues. Finally, in the presence of the herbicide, tadpoles tended to be more active and to stay closer to the bottom of laboratory containers, while tadpole behaviour shifted in the opposite direction in outdoor mesocosms. Our results demonstrate major discrepancies between results of a classic laboratory-based ecotoxicity test and outcomes of an experiment performed in outdoor mesocosms. Consequently, the use of standard laboratory tests may have to be reconsidered and their benefits carefully weighed against the difficulties of performing experiments under more natural conditions. Tests validating experimentally estimated

  4. Comparisons of Derived Metrics from Computed Tomography (CT) Scanned Images of Fluvial Sediment from Gravel-Bed Flume Experiments

    NASA Astrophysics Data System (ADS)

    Voepel, Hal; Ahmed, Sharif; Hodge, Rebecca; Leyland, Julian; Sear, David

    2016-04-01

    Uncertainty in bedload estimates for gravel bed rivers is largely driven by our inability to characterize arrangement, orientation and resultant forces of fluvial sediment in river beds. Water working of grains leads to structural differences between areas of the bed through particle sorting, packing, imbrication, mortaring and degree of bed armoring. In this study, non-destructive, micro-focus X-ray computed tomography (CT) imaging in 3D is used to visualize, quantify and assess the internal geometry of sections of a flume bed that have been extracted keeping their fabric intact. Flume experiments were conducted at 1:1 scaling of our prototype river. From the volume, center of mass, points of contact, and protrusion of individual grains derived from 3D scan data we estimate 3D static force properties at the grain-scale such as pivoting angles, buoyancy and gravity forces, and local grain exposure. Here metrics are derived for images from two flume experiments: one with a bed of coarse grains (>4mm) and the other where sand and clay were incorporated into the coarse flume bed. In addition to deriving force networks, comparison of metrics such as critical shear stress, pivot angles, grain distributions, principle axis orientation, and pore space over depth are made. This is the first time bed stability has been studied in 3D using CT scanned images of sediment from the bed surface to depths well into the subsurface. The derived metrics, inter-granular relationships and characterization of bed structures will lead to improved bedload estimates with reduced uncertainty, as well as improved understanding of relationships between sediment structure, grain size distribution and channel topography.

  5. Comparison of Dental Caries Experience in Children Suffering From Epilepsy with and without Administration of Long Term Liquid Oral Medication

    PubMed Central

    Bhadravathi, Manjunath Chaluvaiah; Kumar, Adarsh; Narang, Ridhi; Gupta, Ambika; Singh, Harneet

    2016-01-01

    Introduction Sucrose is added as sweetening agent in liquid oral medication (LOM) to mask the acrid taste of medicines which may be potentially cariogenic. Many children under long term LOM therapy for treatment of epilepsy may be susceptible to dental caries. Aim To assess and compare dental caries experience in children under long term liquid oral medication with those not under such medication among 2-12 years old children suffering from epilepsy. Materials and Methods A cross-sectional study was undertaken on a total of 84 children aged 2–12 years, who were suffering from epilepsy receiving liquid oral medication for more than 3 months were selected (study group) and for comparison 106 children of similar age group and disease but on other forms of medication were included as control group. Dental caries was assessed using DMFT/DMFS (Decayed, Missing, Fillled Teeth / Surfaces), dmft/dft and dmfs/dfs indices. One-way ANOVA and t-test were used with p-value fixed at 0.05. Univariate logistic regression was applied. Results Children on LOM were at increased risk of dental caries than those with other forms of medications (OR: 2.55, 95% CI (2.37-4.15) p=0.000, HS). Caries prevalence was high in the study group (76.1%) when compared to control group (55.6%). Conclusion Long term use of liquid medicines containing sucrose is a risk factor for dental caries among children with epilepsy. PMID:27504416

  6. Biomechanical comparison of straight and helical compression plates for fixation of transverse and oblique bone fractures: Modeling and experiments.

    PubMed

    Sezek, Sinan; Aksakal, Bunyamin; Gürger, Murat; Malkoc, Melih; Say, Y

    2016-08-12

    Total deformation and stability of straight and helical compression plates were studied by means of the finite element method (FEM) and in vitro biomechanical experiments. Fixations of transverse (TF) and oblique (45°) bone (OF) fractures have been analyzed on sheep tibias by designing the straight compression (SP) and Helical Compression Plate (HP) models. The effects of axial compression, bending and torsion loads on both plating systems were analyzed in terms of total displacements. Numerical models and experimental models suggested that under compression loadings, bone fracture gap closures for both fracture types were found to be in the favor of helical plate designs. The helical plate (HP) fixations provided maximum torsional resistance compared to the (SP) fixations. The fracture gap closure and stability of helical plate fixation for transverse fractures was determined to be higher than that found for the oblique fractures. The comparison of average compression stress, bending and torsion moments showed that the FEM and experimental results are in good agreement and such designs are likely to have a positive impact in future bone fracture fixation designs.

  7. A comparison of airborne and ground-based radar observations with rain gages during the CaPE experiment

    NASA Technical Reports Server (NTRS)

    Satake, Makoto; Short, David A.; Iguchi, Toshio

    1992-01-01

    The vicinity of KSC, where the primary ground truth site of the Tropical Rainfall Measuring Mission (TRMM) program is located, was the focal point of the Convection and Precipitation/Electrification (CaPE) experiment in Jul. and Aug. 1991. In addition to several specialized radars, local coverage was provided by the C-band (5 cm) radar at Patrick AFB. Point measurements of rain rate were provided by tipping bucket rain gage networks. Besides these ground-based activities, airborne radar measurements with X- and Ka-band nadir-looking radars on board an aircraft were also recorded. A unique combination data set of airborne radar observations with ground-based observations was obtained in the summer convective rain regime of central Florida. We present a comparison of these data intending a preliminary validation. A convective rain event was observed simultaneously by all three instrument types on the evening of 27 Jul. 1991. The high resolution aircraft radar was flown over convective cells with tops exceeding 10 km and observed reflectivities of 40 to 50 dBZ at 4 to 5 km altitude, while the low resolution surface radar observed 35 to 55 dBZ echoes and a rain gage indicated maximum surface rain rates exceeding 100 mm/hr. The height profile of reflectivity measured with the airborne radar show an attenuation of 6.5 dB/km (two way) for X-band, corresponding to a rainfall rate of 95 mm/hr.

  8. Comparison of Hydraulic Methods and Tracer Experiments as Applied to the Development of Conceptual Models for Discrete Fracture Networks

    NASA Astrophysics Data System (ADS)

    Novakowski, K. S.

    2015-12-01

    The development of conceptual models for solute migration in discrete fracture networks has typically been based on a combination of core logs, borehole geophysics, and some form of single-well hydraulic test using discrete zones. More rarely, interwell hydraulic tests and interwell tracer experiments are utilised to directly explore potential transport pathways. The latter methods are less widely employed simply due to potentially significant increases in the cost and effort in site characterization. To date however there is a paucity of literature comparing the efficacy of the standard procedure with what should be more definitive identification of transport pathways using interwell methods. In the present study, a detailed comparison is conducted by developing conceptual models from three separate data sets, the first based on core logs, geology and single-well hydraulic tests, the second based on a large suite of pulse interference tests, and the third based on a series of radially-divergent and injection-withdrawal tracer experiments. The study was conducted in an array of five HQ-sized wells, 28-32 m in depth and arranged in a five star pattern, 10 m on a side. The wells penetrate the contact between a Cambrian-aged limestone, and underlying Precambrian gneiss. The core was logged for potentially open fractures using a ranking system, and 87 contiguous hydraulic tests were conducted using a 0.85-m packer spacing. A total of 57 pulse interference tests were conducted using two wells as injection points, and 11 tracer experiments were conducted using either sample collection or in-situ detection via a submersible fluorometer. The results showed very distinct conceptual models depending on the data set, with the model based on the single-well testing significantly over-predicting the number and connection of solute transport pathways. The results of the pulse interference tests also over predict the transport pathways, but to a lesser degree. Quantification of

  9. NSF Research Experience for Undergraduates: 3-D Characterization and Comparison of Vegetation Structure in a Tropical Premontane Wet Forest

    NASA Astrophysics Data System (ADS)

    Washington-Allen, R. A.; Davis, K.; Falkowski, T.; Tarbox, B.; Delgado, A.; March, R.; Moore, G. W.; Tjoelker, M.; Gonzalez, E.; Houser, C.

    2011-12-01

    This National Science Foundation (NSF) Research Experience for Undergraduates (REU) site hosted by Texas A&M University to allow selected undergraduate students to conduct original research on various aspects of the ecohydrology of understudied tropical pre-montane forest at the Texas A&M Soltis Center for Research and Education in Central Costa Rica. This particular study was conducted by 3 students under the guidance of 5 mentors who assisted in experimental design, equipment use, maintenance, and training, plant species identification and other logistical requirements. The goal of this study was to determine the change in 3-D structure of tropical premontane wet forest under 3 different land uses: a carbon tree farm, secondary logged forest, and primary unlogged forest. Traditional forest mensuration techniques including glass prisms (stand basal area), laser clinometers (height), vertical and horizontal PAR, spherical densiometers, and hemispherical photography (GAP fraction and LAI) and, root cores, and diameter-at-breast height (DBH) tapes were acquired in one 30-m diameter plot per land and use compared to similar metrics collected by a terrestrial scanning laser (TSL) and ground penetrating radar (GPR) at 400 MHz and 1.5 GHz across 3 land uses along an elevation gradient from ~380-masl to 525-masl. Besides discovery, another goal of this study was to see if the TSL and GPR can help meet the Tier 2 and 3 monitoring and verification goals of the United Nations Collaborative Programme on Reducing Emissions from Deforestation and Forest Degradation in Developing Countries for estimating above- and below-ground biomass using remote sensing. This is of particular importance because the GPR may be able to capture below-ground biomass in a more efficient manner than traditional coring and the TSL and GPR can capture data on highly sloped terrain where both airborne and satellite RADAR and LIDAR are limited. The 50, 000 pts/sec 532 nm TSL collected 3 to 5 scans per

  10. Kinetics of hybridization on surface oligonucleotide microchips: theory, experiment, and comparison with hybridization on gel-based microchips.

    PubMed

    Sorokin, N V; Chechetkin, V R; Pan'kov, S V; Somova, O G; Livshits, M A; Donnikov, M Y; Turygin, A Y; Barsky, V E; Zasedatelev, A S

    2006-08-01

    The optimal design of oligonucleotide microchips and efficient discrimination between perfect and mismatch duplexes strongly depend on the external transport of target DNA to the cells with immobilized probes as well as on respective association and dissociation rates at the duplex formation. In this paper we present the relevant theory for hybridization of DNA fragments with oligonucleotide probes immobilized in the cells on flat substrate. With minor modifications, our theory also is applicable to reaction-diffusion hybridization kinetics for the probes immobilized on the surface of microbeads immersed in hybridization solution. The main theoretical predictions are verified with control experiments. Besides that, we compared the characteristics of the surface and gel-based oligonucleotide microchips. The comparison was performed for the chips printed with the same pin robot, for the signals measured with the same devices and processed by the same technique, and for the same hybridization conditions. The sets of probe oligonucleotides and the concentrations of probes in respective solutions used for immobilization on each platform were identical as well. We found that, despite the slower hybridization kinetics, the fluorescence signals and mutation discrimination efficiency appeared to be higher for the gel-based microchips with respect to their surface counterparts even for the relatively short hybridization time about 0.5-1 hour. Both the divergence between signals for perfects and the difference in mutation discrimination efficiency for the counterpart platforms rapidly grow with incubation time. In particular, for hybridization during 3 h the signals for gel-based microchips surpassed their surface counterparts in 5-20 times, while the ratios of signals for perfect-mismatch pairs for gel microchips exceeded the corresponding ratios for surface microchips in 2-4 times. These effects may be attributed to the better immobilization efficiency and to the higher

  11. Holocene climatic change in the northern Midwest: a comparison of updated paleoclimate reconstructions and new regional climate model experiments.

    NASA Astrophysics Data System (ADS)

    Shuman, B.; Williams, J. W.; Diffenbaugh, N. S.; Bartlein, P. J.

    2005-12-01

    The mid-continent of North America has long been recognized to have experienced a period of pronounced aridity during the mid-Holocene. A mechanistic explanation for these drier-than-modern conditions, however, has been elusive. Past GCM simulations of 6000 yrs B.P. have failed to produce the strong moisture anomalies inferred from pollen, lake level, diatom, and isotope data, perhaps because important ocean- and land-surface feedbacks were not incorporated into model experiments and because of the coarse resolution of GCMs. Here, we present an updated synthesis of paleoclimatic data from the upper Midwest for comparison with new regional climate model simulations of 6000 yrs B.P. using RegCM2. We focus our analysis on changes in the seasonality of precipitation that may inform our understanding of the climate processes underlying the arid conditions. We use the modern analog technique to infer seasonal moisture levels from fossil pollen data and a simple hydrologic box model to evaluate the seasonal inputs to past lake levels. Patterns in pollen, lake-level, and isotope data support the idea that the dry conditions arose from lower than modern winter precipitation at 6000 yrs B.P.; but existing hypotheses about the dry conditions have often emphasized the contribution of greater than modern summer insolation for producing either high summer evaporative losses or severely reduced summer precipitation as also occurred during the 1930s Dust Bowl drought. Our new RegCM2 simulations appear consistent with our data synthesis. They show widespread negative moisture-balance anomalies in winter and spring, as well as large positive moisture-balance anomalies in summer. The consistency between the data and model imply a need to develop a new framework for understanding the mid-Holocene in the upper Midwest.

  12. Comparison of 2D and 3D Numerical Models with Experiments of Tsunami Flow through a Built Environment

    NASA Astrophysics Data System (ADS)

    LeVeque, R. J.; Motley, M. R.

    2015-12-01

    A series of tsunami wave basin experiments of flow through a scale model of Seaside, Oregon have been used as validation data for a 2015 benchmarking workshop hosted by the National Tsunami Mitigation Program, which focused on better understanding the ability of tsunami models to predict flow velocities and inundation depths following a coastal inundation event. As researchers begin to assess the safety of coastal infrastructures, proper assessment of tsunami-induced forces on coastal structures is critical. Hydrodynamic forces on these structures are fundamentally proportional to the local momentum flux of the fluid, and experimental data included momentum flux measurements at many instrumented gauge locations. The GeoClaw tsunami model, which solves the two-dimensional shallow water equations, was compared against other codes during the benchmarking workshop, and more recently a three-dimensional computational fluid dynamics model using the open-source OpenFOAM software has been developed and results from this model are being compared with both the experimental data and the 2D GeoClaw results. In addition, the 3D model allows for computation of fluid forces on the faces of structures, permitting an investigation of the common use of momentum flux as a proxy for these forces. This work aims to assess the potential to apply these momentum flux predictions locally within the model to determine tsunami-induced forces on critical structures. Difficulties in working with these data sets and cross-model comparisons will be discussed. Ultimately, application of the more computationally efficient GeoClaw model, informed by the 3D OpenFOAM models, to predict forces on structures at the community scale can be expected to improve the safety and resilience of coastal communities.

  13. Dynamics of the D+ + H2 and H+ + D2 reactions: a detailed comparison between theory and experiment.

    PubMed

    Jambrina, P G; Alvariño, J M; Gerlich, D; Hankel, M; Herrero, V J; Sáez-Rábanos, V; Aoiz, F J

    2012-03-14

    An extensive set of experimental measurements on the dynamics of the H(+) + D(2) and D(+) + H(2) ion-molecule reactions is compared with the results of quantum mechanical (QM), quasiclassical trajectory (QCT), and statistical quasiclassical trajectory (SQCT) calculations. The dynamical observables considered include specific rate coefficients as a function of the translational energy, E(T), thermal rate coefficients in the 100-500 K temperature range. In addition, kinetic energy spectra (KES) of the D(+) ions reactively scattered in H(+) + D(2) collisions are also presented for translational energies between 0.4 eV and 2.0 eV. For the two reactions, the best global agreement between experiment and theory over the whole energy range corresponds to the QCT calculations using a gaussian binning (GB) procedure, which gives more weight to trajectories whose product vibrational action is closer to the actual integer QM values. The QM calculations also perform well, although somewhat worse over the more limited range of translational energies where they are available (E(T) < 0.6 eV and E(T) < 0.2 eV for the H(+) + D(2) and D(+) + H(2) reactions, respectively). The worst agreement is obtained with the SQCT method, which is only adequate for low translational energies. The comparison between theory and experiment also suggests that the most reliable rate coefficient measurements are those obtained with the merged beams technique. It is worth noting that none of the theoretical approaches can account satisfactorily for the experimental specific rate coefficients of H(+) + D(2) for E(T)≤ 0.2 eV although there is a considerable scatter in the existing measurements. On the whole, the best agreement with the experimental laboratory KES is obtained with the simulations carried out using the state resolved differential cross sections (DCSs) calculated with the QCT-GB method, which seems to account for most of the observed features. In contrast, the simulations with the SQCT data

  14. Monitoring transport conditions of key comparison travelling standards using a data logger. Experiences from key comparison CCAUV.U-K3.1

    NASA Astrophysics Data System (ADS)

    Haller, Julian; Koch, Christian

    2015-12-01

    In the framework of the international key comparison CCAUV.U-K3.1, a data logger was used to monitor temperature, pressure, humidity, and acceleration during transportation of an artefact travelling between participating laboratories. From the recorded data, environmental conditions of different kinds of transportation have been investigated and corresponding recommendations for the safe and proper transfer of artefacts between laboratories could be deduced. Transportation by courier services bears the risk of strong mechanical shocks and exposure to comparably high or low temperatures due to inappropriate handling or storage and is thus only suitable for insensitive or well-packed artefacts. Quite low temperatures (T  ≈  5 °C) have been observed in the cargo area during flights, so that hand-carrying of an artefact with transportation in the passenger cabin during flights is recommended, particularly for temperature-sensitive artefacts. Significant decreases of the pressure (p  ≈  750 mbar) have been recorded both for transportation in the passenger cabin and in the cargo area. Air-tight packing is thus recommended for pressure-sensitive devices. In general, the suitability of a data logger to provide evidence of the transport conditions during a key comparison has been demonstrated and the use of such a device is recommended for all key comparisons. The data logger has also been successfully employed to validate the protection properties of the passively insulating packaging of the artefact against pressure and temperature changes.

  15. Bromine Explosions In Smog Chamber Experiments: A comparison of Cavity-Enhanced (CE) and White-cell DOAS

    NASA Astrophysics Data System (ADS)

    Buxmann, J.; Hoch, D. J.; Sihler, H.; Pöhler, D.; Platt, U.; Bleicher, S.; Balzer, N.; Zetzsch, C.

    2011-12-01

    Reactive halogen species (RHS), such as Cl, Br or BrO, can significantly influence chemical processes in the troposphere, including the destruction of ozone, change in the chemical balance of hydrogen radicals (OH, HO2), increased deposition of toxic compounds (like mercury) with potential consequences for the global climate. Previous studies have shown that salt lakes can be significant sources for gaseous RHS. Environmental conditions such as salt composition, relative humidity (RH), pH, and temperature (T) can strongly influence reactive bromine levels, but are difficult to quantify in the field. Therefore, we conducted laboratory experiments by exposing NaCl salt containing 0.33% (by weight) NaBr to simulated sunlight in a Teflon smog-chamber under various conditions of RH and ozone concentrations. BrO levels were observed by a Differential-Optical-Absorption-Spectrometer (DOAS) in combination with a multi-reflection cell (White-cell). The concentrations of OH- and Cl- radicals were quantified by the radical clock method. We present the first direct observation of BrO from the "Bromine Explosion" (auto catalytic release of reactive bromine from salt surfaces - key to ozone destruction) in the laboratory above a simulated salt pan. The maximum BrO mixing ratio of 6419±71 ppt at 60% RH was observed to be one order of magnitude higher than at 37% RH and 2% RH. The release of RHS from the salt pan is possibly controlled by the thickness of the quasi liquid layer, covering the reactive surface of the halide crystals, as the layer thickness strongly depends on RH. Furthermore, a new cavity enhanced DOAS (CE-DOAS) instrument was designed and successfully used in chamber experiments. For the first time, such an instrument uses a spectral interval in the UV - wavelength range (325-365 nm) to identify BrO. We show a comparison of the CE-DOAS and White-cell DOAS instrument in a series of experiments, where e.g. a peak BrO mixing ratio up to 380 ppt within the first

  16. Meaning-Making in Memories: A Comparison of Memories of Death-Related and Low Point Life Experiences

    ERIC Educational Resources Information Center

    Mackay, Michael M.; Bluck, Susan

    2010-01-01

    Because of their extensive experience with death and dying, hospice volunteers may be more successful at engaging in meaning-making regarding their death-related experiences than their low point life experiences (e.g., job loss). Consequently, their memories of death-related experiences will manifest more meaning-making strategies (e.g.,…

  17. Comparison of cloud residual and background aerosol particle composition during the hill cap cloud experiment HCCT 2010 in Central Germany

    NASA Astrophysics Data System (ADS)

    Roth, A.; Mertes, S.; van Pinxteren, D.; Klimach, T.; Herrmann, H.; Schneider, J.; Borrmann, S.

    2013-12-01

    Physical and chemical characterization of cloud residual and background aerosol particles as well as aerosol-cloud interactions were investigated during the Hill Cap Cloud Thuringia (HCCT) experiment in September and October 2010 on the mountain site Schmücke (938m a.s.l.) in Germany. Background aerosol particles were sampled by an interstitial inlet whereas cloud droplets from orographic clouds were collected by a counter flow virtual impactor (CVI). Chemical composition analysis and sizing of the particles was done by single particle mass spectrometry using the bipolar Aircraft-based Laser Ablation Aerosol Mass Spectrometer (ALABAMA, particle diameter range 150 nm - 900 nm; Brands et al., 2011) and by two Aerodyne Aerosol Mass Spectrometers (C-ToF, HR-ToF). Supplementary, the particle size distribution was measured with an optical particle counter (OPC, size range 0.25 μm - 32 μm). During the field campaign about 21000 positive and negative single particle mass spectra could be obtained from cloud residual particles and about 239000 from background aerosol particles. The data were clustered by means of the fuzzy c-means algorithm. The resulting clusters consisting of mass spectra with similar fragmentation patterns were, dependent on presence and combination of peaks, assigned to certain particle types. For both sampled particle types a large portion is internally mixed with nitrate and/or sulfate. This might be an explanation, why a comparison of the composition shows a higher fraction of soot particles and amine-containing particles among cloud residuals. Furthermore cloud residuals show a decreased fraction of particles being internally mixed only with nitrate (10%) compared to background aerosol particles (19%) of the same air masses, whereas the fraction of particles containing both nitrate and sulfate increases from 39% to 63% indicating cloud processing by uptake and oxidation of SO2 (Harris et al, 2013). Brands, M., Kamphus, M., Böttger, T., Schneider

  18. Super-thermal particles in hot plasmas—Kinetic models, numerical solution strategies, and comparison to tokamak experiments

    NASA Astrophysics Data System (ADS)

    Lauber, Philipp

    2013-12-01

    The excitation of collective instabilities by super-thermal particles in hot plasmas and the related transport processes attract increasing interest due to their fundamental challenges for theoretical models and their practical importance for burning fusion plasmas. In fact, the physics of a self-heated thermonuclear plasma due to fusion-born 3.5 MeV α-particles is one of the most important outstanding fundamental research topics on the way to a fusion power plant with magnetic confinement. Within the last 10 years significant advances on both the theoretical and the experimental sides have been made leading to a more detailed and quantitative understanding of fast-particle-driven instabilities. On the theoretical side, the crucial step was to move from fluid models for the plasma background with a hybrid kinetic expression for the energetic particles to a fully kinetic model for all the plasma species, i.e. background ions, background electrons, and fast ions. This improvement allows one to describe consistently the resonant interaction between global plasma waves such as shear Alfvén and Alfvén-acoustic waves, and the particles via Landau damping, i.e. the dynamics parallel to the magnetic background field. Also, mode conversion mechanisms require the inclusion of background ion scales in a kinetic, non-perturbative way. This accurate treatment of the plasma background leads not only to changes in the linear mode properties such as frequency, growth/damping rate, and mode structure but also influences the non-linear dynamics. Due to major advances, innovations and installation of diagnostics in present day experiments, this comparison can be carried out in a more detailed and comprehensive way than a few years ago. For example, the measurement of damping rates via active external antennas, the imaging of 2D mode structures via electron-cyclotron-emission spectroscopy, and the direct detection of escaping fast ions allow to diagnose various kinetic features of

  19. Perturbative transport modeling and comparison to cold-pulse and heat-pulse propagation experiments in Alcator C-Mod and DIII-D

    NASA Astrophysics Data System (ADS)

    Rodriguez Fernandez, P.; White, A. E.; Cao, N. M.; Creely, A. J.; Greenwald, M. J.; Howard, N. T.; Hubbard, A. E.; Hughes, J. W.; Irby, J. H.; Petty, C. C.; Rice, J. E.; Alcator C-Mod Team

    2016-10-01

    Possible ``non-local'' transport phenomena are often observed in tokamak plasmas. Different models have been proposed to explain fast responses during perturbative transport experiments, including non-diffusive effects. Specific tools to characterize the dynamic behavior and power balance analysis using TRANSP and the quasi-linear trapped gyro-landau fluid code TGLF have been developed to analyze Alcator C-Mod experiments. Recent results from cold pulse experiments show that fast core temperature increases following edge cold-pulse injections (peak within 10ms , while τE 25ms) are not correlated with the direction of intrinsic rotation, and instead the amplitude of the core response depends on density, plasma current and RF input power. The propagation of the cold pulse can be compared with propagation of heat pulses from sawteeth, and both may be used to probe changes in temperature profile stiffness. A Laser Blow Off (LBO) system is being developed for DIII-D that will allow further validation and cross-machine comparison of cold pulse experiments. LBO at DIII-D will also allow for direct comparisons with ECH perturbative heat pulse experiments. Work supported by US DOE under Grants DE-FC02-99ER54512 (C-Mod) and DE-FC02-04ER54698 (DIII-D) and La Caixa Fellowship.

  20. COMPARISON OF EXPERIMENTS TO CFD MODELS FOR MIXING USING DUAL OPPOSING JETS IN TANKS WITH AND WITHOUT INTERNAL OBSTRUCTIONS

    SciTech Connect

    Leishear, R.; Poirier, M.; Lee, S.; Fowley, M.

    2012-06-26

    This paper documents testing methods, statistical data analysis, and a comparison of experimental results to CFD models for blending of fluids, which were blended using a single pump designed with dual opposing nozzles in an eight foot diameter tank. Overall, this research presents new findings in the field of mixing research. Specifically, blending processes were clearly shown to have random, chaotic effects, where possible causal factors such as turbulence, pump fluctuations, and eddies required future evaluation. CFD models were shown to provide reasonable estimates for the average blending times, but large variations -- or scatter -- occurred for blending times during similar tests. Using this experimental blending time data, the chaotic nature of blending was demonstrated and the variability of blending times with respect to average blending times were shown to increase with system complexity. Prior to this research, the variation in blending times caused discrepancies between CFD models and experiments. This research addressed this discrepancy, and determined statistical correction factors that can be applied to CFD models, and thereby quantified techniques to permit the application of CFD models to complex systems, such as blending. These blending time correction factors for CFD models are comparable to safety factors used in structural design, and compensate variability that cannot be theoretically calculated. To determine these correction factors, research was performed to investigate blending, using a pump with dual opposing jets which re-circulate fluids in the tank to promote blending when fluids are added to the tank. In all, eighty-five tests were performed both in a tank without internal obstructions and a tank with vertical obstructions similar to a tube bank in a heat exchanger. These obstructions provided scale models of vertical cooling coils below the liquid surface for a full scale, liquid radioactive waste storage tank. Also, different jet

  1. The American Indian Family in Los Angeles: A Comparison of Premigration Experience, Postmigration Residence and Employment Mobility, and Coping Strategies.

    ERIC Educational Resources Information Center

    Weibel, Joan

    Urban adaptation patterns of male and female American Indians were investigated via comparison of premigration statistics (48 Navajo and 40 Oklahoma families) with postmigration statistics on a sample of 23 Navajo and 21 Oklahoma families now living in Los Angeles. The premigration variables were residence patterns; population density;…

  2. Birch's law for high-pressure metals and ionic solids: Sound velocity data comparison between shock wave experiments and recent diamond anvil cell experiments

    NASA Astrophysics Data System (ADS)

    Boness, David A.; Ware, Lucas

    2017-01-01

    Sound velocity-density systematics has long been a fruitful way to take shock wave measurements on elements, alloys, oxides, rocks, and other materials, and allow reasonable extrapolation to densities found deep in the Earth. Recent detection of super-Earths has expanded interest in terrestrial planetary interiors to an even greater range of materials and pressures. Recent published diamond anvil cell (DAC) experimental measurements of sound velocities in iron and iron alloys, relevant to planetary cores, are inconsistent with each other with regard to the validity of Birch's Law, a linear relation between sound velocity and density. We examine the range of validity of Birch's Law for several shocked metallic elements, including iron, and shocked ionic solids and make comparisons to the recent DAC data.

  3. Nursing Students' Experiences with and Strategic Approaches to Case-Based Instruction: A Replication and Comparison Study between Two Disciplines.

    ERIC Educational Resources Information Center

    DeMarco, Rosanna; Hayward, Lorna; Lynch, Marcia

    2002-01-01

    Analysis of nursing student experiences in a case-based course yielded six themes: motivation, real world, learning, knowledge development, emergence from within, and group dynamics. Nursing students' experience was similar to that of physical therapy students, supporting development of an interdisciplinary, case-based course addressing…

  4. Comparison of CFD simulations to non-rotating MEXICO blades experiment in the LTT wind tunnel of TUDelft

    NASA Astrophysics Data System (ADS)

    Zhang, Ye; van Zuijlen, Alexander; van Bussel, Gerard

    2014-06-01

    In this paper, three dimensional flow over non-rotating MEXICO blades is simulated by CFD methods. The numerical results are compared with the latest MEXICO wind turbine blades measurements obtained in the low speed low turbulence (LTT) wind tunnel of Delft University of Technology. This study aims to validate CFD codes by using these experimental data measured in well controlled conditions. In order to avoid use of wind tunnel corrections, both the blades and the wind tunnel test section are modelled in the simulations. The ability of Menter's k - ω shear stress transport (SST) turbulence model is investigated at both attached flow and massively separated flow cases. Steady state Reynolds averaged Navier Stokes (RANS) equations are solved in these computations. The pressure distribution at three measured sections are compared under the conditions of different inflow velocities and a range of angles of attack. The comparison shows that at attached flow condition, good agreement can be obtained for all three airfoil sections. Even with massively separated flow, still fairly good pressure distribution comparison can be found for the DU and NACA airfoil sections, although the RISØ section shows poor comparison. At the near stall case, considerable deviations exists on the forward half part of the upper surface for all three sections.

  5. Cross-national comparison of prenatal methamphetamine exposure on infant and early child physical growth: A natural experiment

    PubMed Central

    Abar, Beau; LaGasse, Linda L.; Wouldes, Trecia; Derauf, Chris; Newman, Elana; Shah, Rizwan; Smith, Lynne M.; Arria, Amelia M.; Huestis, Marilyn A.; DellaGrotta, Sheri; Dansereau, Lynne M.; Wilcox, Tara; Neal, Charles R.; Lester, Barry M.

    2013-01-01

    The current study seeks to compare the effects of prenatal methamphetamine exposure (PME) on infant and child physical growth between the United States (US) and New Zealand (NZ). This cross-national comparison provides a unique opportunity to examine the potential impact of services provided to drug using mothers on child health. Methods The longitudinal Infant Development, Environment and Lifestyle (IDEAL) study of PME from birth to 36 months was conducted in the US and NZ. The US cohort included 204 children with PME and 212 non-PME matched comparisons (NPME); the NZ cohort included 108 children with PME and 115 NPME matched comparisons. Latent growth curve models were used to examine effects of PME, country of origin, and the country × PME interaction on growth in length/height and weight. Results In regard to length/height, PME and country of origin were associated with initial length and growth over time. There was also a significant interaction effect, such that children with PME in the US were shorter at birth than children with PME in NZ after controlling for other prenatal exposures, infant set, socioeconomic status, and maternal height. In regard to weight, there was only an effect of country of origin. Conclusions Effects of PME on infant and child growth were shown to differ across countries, with exposed children in NZ faring better than exposed children in the US. Implications for prevention programs and public policy are discussed. PMID:23943149

  6. Cross-national comparison of prenatal methamphetamine exposure on infant and early child physical growth: a natural experiment.

    PubMed

    Abar, Beau; LaGasse, Linda L; Wouldes, Trecia; Derauf, Chris; Newman, Elana; Shah, Rizwan; Smith, Lynne M; Arria, Amelia M; Huestis, Marilyn A; DellaGrotta, Sheri; Dansereau, Lynne M; Wilcox, Tara; Neal, Charles R; Lester, Barry M

    2014-10-01

    The current study seeks to compare the effects of prenatal methamphetamine exposure (PME) on infant and child physical growth between the USA and New Zealand (NZ). This cross-national comparison provides a unique opportunity to examine the potential impact of services provided to drug using mothers on child health. The longitudinal Infant Development, Environment and Lifestyle study of PME from birth to 36 months was conducted in the USA and NZ. The US cohort included 204 children with PME and 212 non-PME matched comparisons (NPME); the NZ cohort included 108 children with PME and 115 NPME matched comparisons. Latent growth curve models were used to examine effects of PME, country of origin, and the country × PME interaction on growth in length/height and weight. In regard to length/height, PME and country of origin were associated with initial length and growth over time. There was also a significant interaction effect, such that children with PME in the USA were shorter at birth than children with PME in NZ after controlling for other prenatal exposures, infant set, socioeconomic status, and maternal height. In regard to weight, there was only an effect of country of origin. Effects of PME on infant and child growth were shown to differ across countries, with exposed children in NZ faring better than exposed children in the USA. Implications for prevention programs and public policy are discussed.

  7. Impact of dynamic specimen shape evolution on the atom probe tomography results of doped epitaxial oxide multilayers: Comparison of experiment and simulation

    SciTech Connect

    Madaan, Nitesh; Nandasiri, Manjula; Devaraj, Arun; Bao, Jie; Xu, Zhijie; Thevuthasan, Suntharampillai

    2015-08-31

    The experimental atom probe tomography (APT) results from two different specimen orientations (top-down and sideways) of a high oxygen ion conducting Samaria-doped-ceria/Scandia-stabilized-zirconia multilayer thin film solid oxide fuel cell electrolyte was compared with level-set method based field evaporation simulations for the same specimen orientations. This experiment-simulation comparison explains the dynamic specimen shape evolution and ion trajectory aberrations that can induce density artifacts in final reconstruction, leading to inaccurate estimation of interfacial intermixing. This study highlights the importance of comparing experimental results with field evaporation simulations when using APT to study oxide heterostructure interfaces.

  8. Application of the RNS3D Code to a Circular-Rectangular Transition Duct With and Without Inlet Swirl and Comparison with Experiments

    NASA Technical Reports Server (NTRS)

    Cavicchi, Richard H.

    1999-01-01

    Circular-rectangular transition ducts are used between engine exhausts and nozzles with rectangular cross sections that are designed for high performance aircraft. NASA Glenn Research Center has made experimental investigations of a series of circular-rectangular transition ducts to provide benchmark flow data for comparison with numerical calculations. These ducts are all designed with superellipse cross sections to facilitate grid generation. In response to this challenge, the three-dimensional RNS3D code has been applied to one of these transition ducts. This particular duct has a length-to-inlet diameter ratio of 1.5 and an exit-plane aspect ratio of 3.0. The inlet Mach number is 0.35. Two GRC experiments and the code were run for this duct without inlet swirl. One GRC experiment and the code were also run with inlet swirl. With no inlet swirl the code was successful in predicting pressures and secondary flow conditions, including a pair of counter-rotating vortices at both sidewalls of the exit plane. All these phenomena have been reported from the two GRC experiments. However, these vortices were suppressed in the one experiment when inlet swirl was used; whereas the RNS3D code still predicted them. The experiment was unable to provide data near the sidewalls, the very region where the vortices were predicted.

  9. A Comparison of a Traditional Clinical Experience to a Precepted Clinical Experience for Baccalaureate-Seeking Nursing Students in Their Second Semester

    PubMed Central

    Ownby, Kristin; Schumann, Renae; Dune, Linda; Kohne, David

    2012-01-01

    The shortage of nursing faculty has contributed greatly to the nursing workforce shortage, with many schools turning away qualified applicants because there are not enough faculty to teach. Despite the faculty shortage, schools are required to admit more students to alleviate the nursing shortage. Clinical groups in which preceptors are responsible for student learning extend faculty resources. Purpose. To determine the effectiveness of an alternative clinical experience (preceptorship). Methods. quasi-experimental, randomized, longitudinal design. Students were randomized to either the traditional or precepted clinical group. The clinical experience was a total of 12 weeks. Groups were compared according to several variables including second semester exam scores, HESI scores, and quality and timeliness of clinical paperwork. Sample. Over a two-year period, seventy-one undergraduate nursing students in the second semester medical-surgical nursing course participated. 36 were randomized to the experimental group. The preceptors were baccalaureate-prepared nurses who have been practicing for at least one year. Setting. Two hospitals located in the Texas Medical Center. Statistical Analysis. Descriptive statistics and independent t-test. Results. There was no difference between the groups on the variables of interest. Conclusion. Students in the precepted clinical group perform as well as those in a traditional clinical group. PMID:22577535

  10. Assessment of Habitat Suitability Is Affected by Plant-Soil Feedback: Comparison of Field and Garden Experiment

    PubMed Central

    Hemrová, Lucie; Knappová, Jana; Münzbergová, Zuzana

    2016-01-01

    Background Field translocation experiments (i.e., the introduction of seeds or seedlings of different species into different localities) are commonly used to study habitat associations of species, as well as factors limiting species distributions and local abundances. Species planted or sown in sites where they naturally occur are expected to perform better or equally well compared to sites at which they do not occur or are rare. This, however, contrasts with the predictions of the Janzen-Connell hypothesis and commonly reported intraspecific negative plant-soil feedback. The few previous studies indicating poorer performance of plants at sites where they naturally occur did not explore the mechanisms behind this pattern. Aims and Methods In this study, we used field translocation experiments established using both seeds and seedlings to study the determinants of local abundance of four dominant species in grasslands. To explore the possible effects of intraspecific negative plant-soil feedback on our results, we tested the effect of local species abundance on the performance of the plants in the field experiment. In addition, we set up a garden experiment to explore the intensity of intraspecific as well as interspecific feedback between the dominants used in the experiment. Key Results In some cases, the distribution and local abundances of the species were partly driven by habitat conditions at the sites, and species performed better at their own sites. However, the prevailing pattern was that the local dominants performed worse at sites where they naturally occur than at any other sites. Moreover, the success of plants in the field experiment was lower in the case of higher intraspecific abundance prior to experimental setup. In the garden feedback experiment, two of the species performed significantly worse in soils conditioned by their species than in soils conditioned by the other species. In addition, the performance of the plants was significantly

  11. Initial results from a mesoscale atmospheric simulation system and comparisons with the AVE-SESAME I data set. [Atmospheric Variability Experiment-Severe Environmental Storms And Mesoscale Experiment

    NASA Technical Reports Server (NTRS)

    Kaplan, M. L.; Zack, J. W.; Wong, V. C.; Tuccillo, J. J.

    1982-01-01

    The development of a comprehensive mesoscale atmospheric simulation system (MASS) is described in detail. The modeling system is designed for both research and real-time forecast applications. The 14-level numerical model, which has a 48 km grid mesh, can be run over most of North America and the adjacent oceanic regions. The model employs sixth-order accurate numerics, generalized similarity theory boundary-layer physics, a sophisticated cumulus parameterization scheme, and state of the art analysis and initialization techniques. Examples of model output on the synoptic and subsynoptic scales are presented for the AVE-SESAME I field experiment on 10-11 April 1979. The model output is subjectively compared to the observational analysis and the LFM II output on the synoptic scale. Subsynoptic model output is compared to analyses generated from the AVE-SESAME I data set.

  12. Approximate first-principles anharmonic calculations of polyatomic spectra using MP2 and B3LYP potentials: comparisons with experiment.

    PubMed

    Roy, Tapta Kanchan; Carrington, Tucker; Gerber, R Benny

    2014-08-21

    Anharmonic vibrational spectroscopy calculations using MP2 and B3LYP computed potential surfaces are carried out for a series of molecules, and frequencies and intensities are compared with those from experiment. The vibrational self-consistent field with second-order perturbation correction (VSCF-PT2) is used in computing the spectra. The test calculations have been performed for the molecules HNO3, C2H4, C2H4O, H2SO4, CH3COOH, glycine, and alanine. Both MP2 and B3LYP give results in good accord with experimental frequencies, though, on the whole, MP2 gives very slightly better agreement. A statistical analysis of deviations in frequencies from experiment is carried out that gives interesting insights. The most probable percentage deviation from experimental frequencies is about -2% (to the red of the experiment) for B3LYP and +2% (to the blue of the experiment) for MP2. There is a higher probability for relatively large percentage deviations when B3LYP is used. The calculated intensities are also found to be in good accord with experiment, but the percentage deviations are much larger than those for frequencies. The results show that both MP2 and B3LYP potentials, used in VSCF-PT2 calculations, account well for anharmonic effects in the spectroscopy of molecules of the types considered.

  13. A comparison of two differential methods for nutrition education in elementary school: lecture-and experience-based learning program

    PubMed Central

    Jung, Lan-Hee; Choi, Jeong-Hwa; Bang, Hyun-Mi; Shin, Jun-Ho

    2015-01-01

    BACKGROUND/OBJECTIVES This research was conducted to compare lecture-and experience-based methods of nutritional education as well as provide fundamental data for developing an effective nutritional education program in elementary schools. SUBJECTS/METHODS A total of 110 students in three elementary schools in Jeollanam-do were recruited and randomly distributed in lecture-and experience-based groups. The effects of education on students' dietary knowledge, dietary behaviors, and dietary habits were analyzed using a pre/post-test. RESULTS Lecture-and experience-based methods did not significantly alter total scores for dietary knowledge in any group, although lecture-based method led to improvement for some detailed questions. In the experience-based group, subjects showed significant alteration of dietary behaviors, whereas lecture-based method showed alteration of dietary habits. CONCLUSIONS These outcomes suggest that lecture-and experience-based methods led to differential improvement of students' dietary habits, behaviors, and knowledge. To obtain better nutritional education results, both lectures and experiential activities need to be considered. PMID:25671073

  14. Are all ostracism experiences equal? A comparison of the autobiographical recall, Cyberball, and O-Cam paradigms.

    PubMed

    Godwin, Alexandra; MacNevin, Georgia; Zadro, Lisa; Iannuzzelli, Rose; Weston, Stephanie; Gonsalkorale, Karen; Devine, Patricia

    2014-09-01

    In the present study, we aimed to compare the primary-need depletion elicited by three common ostracism paradigms: autobiographical recall (e.g., Zhong & Leonardelli in Psychological Science 19:838-842, 2008), Cyberball (Williams, Cheung, & Choi in Journal of Personality and Social Psychology 79:748-762, 2000), and O-Cam (Goodacre & Zadro in Behavior Research Methods 42:768-774, 2010). A total of 152 participants (52 males) were randomly allocated to one of the three paradigms, and their subsequent primary needs were measured (belonging, control, self-esteem, and meaningful existence). O-Cam was found to induce greater total primary-need depletion than did Cyberball and recall, which did not differ significantly from each other. Moreover, when examining the pattern of individual need depletion elicited by each paradigm, O-Cam was found to induce significantly greater depletion of belonging, control, and meaningful existence than did the recall paradigm, and significantly greater depletion of control and self-esteem than did Cyberball. No other comparisons were found to be significant, including the comparisons between the recall and Cyberball paradigms for each individual primary need. Collectively, the findings will assist ostracism researchers in making informed choices regarding (a) which paradigm is appropriate to implement with respect to their research aims, and (b) whether the interchangeable use of paradigms within a program of research is appropriate practice.

  15. Martian atmosphere modeling between 0.4 and 3.5 microns - Comparison of theory and experiment

    NASA Technical Reports Server (NTRS)

    Egan, W. G.; Fischbein, W. L.; Hilgeman, T.; Smith, L. L.

    1978-01-01

    A model of the lower atmosphere of Mars has been constructed that combines aerosol absorption and scattering with a line-by-line analysis of CO2 and H2O in a multilayer radiative transfer program. Aerosol composition previously inferred from the NASA Lear Jet Observatory data was used to measure the optical complex indices of refraction of appropriate Martian analogs from 0.4 to 2.5 microns. The aerosol vertical particle density scale was deduced using the Viking camera observations of the soil and sky intensities between 0.4 and 1.0 microns in comparison with those modeled using a multilayer Mie scattering program. A comparison of observed Mars atmospheric absorptions was made with those obtained using Lorentz, Voigt, and Doppler line profiles in a multilayer model of the CO2 and H2O. The Voigt line profile of CO2 absorption at approximately 4976 kaysers was then combined in a multilayer aerosol model of the Martian atmosphere. An evaluation of the effect on the line shape was made using several aerosol loadings.

  16. Assessing the effects of cognitive experiments on the welfare of captive chimpanzees (Pan troglodytes) by direct comparison of activity budget between wild and captive chimpanzees.

    PubMed

    Yamanashi, Yumi; Hayashi, Misato

    2011-12-01

    We investigated the effects of cognitive experiments by direct comparison of activity budgets between wild and captive chimpanzees. One goal of captive management is to ensure that the activity budgets of captive animals are as similar as possible to those of their wild counterparts. However, such similarity has rarely been achieved. We compared the activity budget among three groups of chimpanzees: wild chimpanzees in Bossou (Guinea, n = 10), and captive chimpanzees who participated in cognitive experiments (experimental chimpanzees, n = 6) or did not participate in the experiments (nonexperimental chimpanzees, n = 6) at the Primate Research Institute (Japan). The experimental chimpanzees voluntarily participated in computer-controlled cognitive tasks and small pieces of fruits were provided as rewards. The data from captivity were obtained on the experimental days (weekdays) and nonexperimental days (weekends). In both study sites, we followed each chimpanzee from about 7 a.m. until the time when chimpanzees started to rest in the evening. The behaviors were recorded every 1 min. The results showed that on weekdays, feeding time and resting time of the experimental chimpanzees were almost the same as those of wild chimpanzees. However, for the nonexperimental chimpanzees, feeding time was significantly shorter and resting time was longer than those of the wild chimpanzees. In contrast, no difference was found in feeding time or resting time of the two groups of captive chimpanzees on weekends. The results suggested that the cognitive experiments worked as an efficient method for food-based enrichment.

  17. Parametric dependence of density limits in the Tokamak Experiment for Technology Oriented Research (TEXTOR): Comparison of thermal instability theory with experiment

    NASA Astrophysics Data System (ADS)

    Kelly, F. A.; Stacey, W. M.; Rapp, J.

    2001-11-01

    The observed dependence of the TEXTOR [Tokamak Experiment for Technology Oriented Research: E. Hintz, P. Bogen, H. A. Claassen et al., Contributions to High Temperature Plasma Physics, edited by K. H. Spatschek and J. Uhlenbusch (Akademie Verlag, Berlin, 1994), p. 373] density limit on global parameters (I, B, P, etc.) and wall conditioning is compared with the predicted density limit parametric scaling of thermal instability theory. It is necessary first to relate the edge parameters of the thermal instability theory to n¯ and the other global parameters. The observed parametric dependence of the density limit in TEXTOR is generally consistent with the predicted density limit scaling of thermal instability theory. The observed wall conditioning dependence of the density limit can be reconciled with the theory in terms of the radiative emissivity temperature dependence of different impurities in the plasma edge. The thermal instability theory also provides an explanation of why symmetric detachment precedes radiative collapse for most low power shots, while a multifaceted asymmetric radiation from the edge MARFE precedes detachment for most high power shots.

  18. The Influence of Reasons for Attending University on University Experience: A Comparison between Students with and without Disabilities

    ERIC Educational Resources Information Center

    Reed, Maureen J.; Kennett, Deborah J.; Emond, Marc

    2015-01-01

    Students choose to go to university for many reasons. They include those with disabilities and those without. The reasons why students with disabilities go to university and how these reasons impact university experience, including coping (academic resourcefulness), adapting, academic ability beliefs (academic self-efficacy), and grades, are…

  19. Dust Impact Monitor (DIM) onboard Rosetta/Philae: Comparison of experimental results and the theory behind the experiment

    NASA Astrophysics Data System (ADS)

    Flandes, Alberto; Krüger, Harald; Loose, Alexander; Sperl, Matthias; Jürgen Seidensticker, Klaus; Fischer, Hans-Herbert; Arnold, Walter

    2013-08-01

    The Dust Impact Monitor (DIM) experiment on board the Rosetta spacecraft's lander, Philae, is a cube with three sides covered with piezo-electric (PZT) sensors (total sensitive area: ≈70cm2), aimed at measuring the physical properties of millimetric and sub-millimetric dust particles that move near the surface of comet 67P/Churyumov - Gerasimenko. In this work we study the performance of the DIM Flight Spare (FS) unit based on impact experiments and compare the measurements with the sensor's expected theoretical behavior as derived from Hertz' theory of elastic impact. We present the results of impact experiments performed with spherical particles of different densities and elastic properties. We performed two types of experiments: (a) we analyze the performance of the different sensor sides under identical impacts, and (b) we investigate the performance of DIM under impacts of different materials and different impact speeds. We discuss the possible influence of the microstructure of the PZT sensor on the signal strength and its variation with position of the impacting particles. Our results show that the signal strength and the contact times measured with the DIM PZT sensors can be well approximated by Hertz' contact mechanics.

  20. Dissociative Experiences of Sexual Offenders: A Comparison between Two Outpatient Groups and Those Found to be Falsely Accused.

    ERIC Educational Resources Information Center

    Dwyer, S. Margretta

    1992-01-01

    Administered Dissociative Experiences Scale, which distinguishes between subjects with dissociative disorder and those without, to 71 sex offenders and 14 men who were falsely accused of sexual abuse. Outpatient sex offenders scored in the range attributed to general population. Those falsely accused of child sexual abuse scored lower than…

  1. Reconsidering the Local after a Transformative Global Experience: A Comparison of Two Study Abroad Programs for Preservice Teachers

    ERIC Educational Resources Information Center

    Dunn, Alyssa Hadley; Dotson, Erica K.; Cross, Stephanie Behm; Kesner, John; Lundahl, Bo

    2014-01-01

    This comparative case study analyzes two study abroad experiences for preservice teachers--a 4-month student teaching placement in Sweden and a 3-week intensive intercultural course with school observations in France. Although they differed in duration and structure, both programs focused on developing preservice teachers' understandings of…

  2. Childhood Experiences of Sexual Abuse and Later Parenting Practices among Non-Offending Mothers of Sexually Abused and Comparison Girls

    ERIC Educational Resources Information Center

    Kim, Kihyun; Trickett, Penelope K.; Putnam, Frank W.

    2010-01-01

    Objective: The primary goal of this study was to explore the relationship between childhood sexual abuse and parenting practices among non-offending mothers of sexually abused girls. Guided by a developmental-ecological perspective of parenting, several models with different potential pathways starting from the mothers' childhood experiences of…

  3. A Comparison of Supervised Occupational Experience Programs Conducted by Males and Females in Wyoming. A Report of Research.

    ERIC Educational Resources Information Center

    Reynolds, Carl L.

    A study was conducted in Wyoming to determine the scope and economic value of supervised occupational experience programs (SOEPs) in vocational agriculture. The study tried to determine the level of participation and success realized by females engaged in SOEP activities, and to find out to what degree males and females engage in balanced SOEPs,…

  4. Examining the Internal Validity and Statistical Precision of the Comparative Interrupted Time Series Design by Comparison with a Randomized Experiment

    ERIC Educational Resources Information Center

    St.Clair, Travis; Cook, Thomas D.; Hallberg, Kelly

    2014-01-01

    Although evaluators often use an interrupted time series (ITS) design to test hypotheses about program effects, there are few empirical tests of the design's validity. We take a randomized experiment on an educational topic and compare its effects to those from a comparative ITS (CITS) design that uses the same treatment group as the experiment…

  5. Study Abroad in a Developing and a Developed Country: A Comparison of American Undergraduate Students' Experiences in Ghana and England

    ERIC Educational Resources Information Center

    Costa, Maria

    2012-01-01

    This qualitative study examined the differences among the experiences of 7 American undergraduate students; 4 who studied for a semester in Ghana, a developing country, and 3 who studied for a semester in England, a developed country. Using phenomenology as its guiding framework, transcribed interviews were analyzed and the focal phenomenon of the…

  6. A Comparison of the First-Year Experience Programming to Enhance the Retention of Future Allied Health Professionals

    ERIC Educational Resources Information Center

    Whalen, Tina Forsythe

    2012-01-01

    This mixed-methods case study examined the effectiveness of a new first-year experience (FYE) curriculum for selected Choose Ohio First Scholars in the College of Allied Health Sciences (CAHS) and compared it with the effectiveness of the traditional FYE curriculum in CAHS. The quantitative phase of the study involved the collection and analysis…

  7. A Comparison of the Concepts of Democracy and Experience in a Sample of Major Works by Dewey and Freire

    ERIC Educational Resources Information Center

    Shyman, Eric

    2011-01-01

    While theorizing in distinctly different times, distinctly different cultures, and under distinctly different circumstances, notable philosophical similarities can be drawn between John Dewey and Paulo Freire. This article focuses on two major themes evident in a sample of each philosopher's major works, democracy and experience, and draws…

  8. Clinical experience of the use of adalimumab in the management of hidradenitis suppurativa. Comparison of response rates with Crohn disease.

    PubMed

    Moyano, B; Clemente, A; Marín-Jiménez, I; Martorell, A

    2016-09-01

    The recent approval of adalimumab as the first treatment to be approved for the management of hidradenitis suppurativa has represented a before and after in the control of this chronic inflammatory disease. Given the inflammatory burden of this cutaneous disease, in the last few years hidradenitis suppurativa has been compared with inflammatory bowel disease, particularly with Crohn disease, to the point of considering hidradenitis suppurativa as "Crohn disease of the skin". These two chronic inflammatory diseases show sufficient similarities to consider whether treatment response based on the inflammatory load could also be similar. The present article aims to analyse the efficacy of adalimumab in hidradenitis suppurativa in comparison with a truly comparable disease, Crohn disease, with a view to evaluating therapeutic response rates and to drawing conclusions on the therapeutic success obtained in this disabling cutaneous disease.

  9. Investigation, comparison and design of chambers used in centrifugal partition chromatography on the basis of flow pattern and separation experiments.

    PubMed

    Schwienheer, C; Merz, J; Schembecker, G

    2015-04-17

    In centrifugal partition chromatography (CPC) the separation efficiency is mainly influenced by the hydrodynamic of mobile and stationary phase in the chambers. Thus, the hydrodynamic has to be investigated and understood in order to enhance a CPC separation run. Different chamber geometries have been developed in the past and the influence of several phase systems and CPC operating conditions were investigated for these chambers. However, a direct comparison between the different chamber types has not been performed yet. In order to investigate the direct influence of the chamber design on the hydrodynamic, several chamber designs - partially similar in geometry to commercial available designs - are investigated under standardized conditions in the present study. The results show the influence of geometrical aspects of the chamber design on the hydrodynamic and therewith, on the separation efficiency. As a conclusion of the present study, some ideas for an optimal chamber design for laboratory and industrial purpose are proposed.

  10. Investigation of the current yaw engineering models for simulation of wind turbines in BEM and comparison with CFD and experiment

    NASA Astrophysics Data System (ADS)

    Rahimi, H.; Hartvelt, M.; Peinke, J.; Schepers, J. G.

    2016-09-01

    The aim of this work is to investigate the capabilities of current engineering tools based on Blade Element Momentum (BEM) and free vortex wake codes for the prediction of key aerodynamic parameters of wind turbines in yawed flow. Axial induction factor and aerodynamic loads of three wind turbines (NREL VI, AVATAR and INNWIND.EU) were investigated using wind tunnel measurements and numerical simulations for 0 and 30 degrees of yaw. Results indicated that for axial conditions there is a good agreement between all codes in terms of mean values of aerodynamic parameters, however in yawed flow significant deviations were observed. This was due to unsteady phenomena such as advancing & retreating and skewed wake effect. These deviations were more visible in aerodynamic parameters in comparison to the rotor azimuthal angle for the sections at the root and tip where the skewed wake effect plays a major role.

  11. Simulation studies of the Cl- + CH3I SN2 nucleophilic substitution reaction: Comparison with ion imaging experiments

    NASA Astrophysics Data System (ADS)

    Zhang, Jiaxu; Lourderaj, Upakarasamy; Sun, Rui; Mikosch, Jochen; Wester, Roland; Hase, William L.

    2013-03-01

    In the previous work of Mikosch et al. [Science 319, 183 (2008)], 10.1126/science.1150238, ion imaging experiments were used to study the Cl- + CH3I → ClCH3 + I- reaction at collision energies Erel of 0.39, 0.76, 1.07, and 1.9 eV. For the work reported here MP2(fc)/ECP/d direct dynamics simulations were performed to obtain an atomistic understanding of the experiments. There is good agreement with the experimental product energy and scattering angle distributions for the highest three Erel, and at these energies 80% or more of the reaction is direct, primarily occurring by a rebound mechanism with backward scattering. At 0.76 eV there is a small indirect component, with isotropic scattering, involving formation of the pre- and post-reaction complexes. All of the reaction is direct at 1.07 eV. Increasing Erel to 1.9 eV opens up a new indirect pathway, the roundabout mechanism. The product energy is primarily partitioned into relative translation for the direct reactions, but to CH3Cl internal energy for the indirect reactions. The roundabout mechanism transfers substantial energy to CH3Cl rotation. At Erel = 0.39 eV both the experimental product energy partitioning and scattering are statistical, suggesting the reaction is primarily indirect with formation of the pre- and post-reaction complexes. However, neither MP2 nor BhandH/ECP/d simulations agree with experiment and, instead, give reaction dominated by direct processes as found for the higher collision energies. Decreasing the simulation Erel to 0.20 eV results in product energy partitioning and scattering which agree with the 0.39 eV experiment. The sharp transition from a dominant direct to indirect reaction as Erel is lowered from 0.39 to 0.20 eV is striking. The lack of agreement between the simulations and experiment for Erel = 0.39 eV may result from a distribution of collision energies in the experiment and/or a shortcoming in both the MP2 and BhandH simulations. Increasing the reactant rotational

  12. Biodegradation of the surfactant linear alkylbenzenesulfonate in sewage- contaminated groundwater: A comparison of column experiments and field tracer tests

    USGS Publications Warehouse

    Krueger, C.J.; Radakovich, K.M.; Sawyer, T.E.; Barber, L.B.; Smith, R.L.; Field, J.A.

    1998-01-01

    Transport and biodegradation of linear alkylbenzenesulfonate (LAS) in sewage-contaminated groundwater were investigated for a range of dissolved oxygen concentrations. Both laboratory column and an 80-day continuous injection tracer test field experiments were conducted. The rates of LAS biodegradation increased with increasing dissolved oxygen concentrations and indicated the preferential biodegradation of the longer alkyl chain LAS homologues (i.e., C12 and C13) and external isomers (i.e., 2-and 3- phenyl). However, for similar dissolved oxygen concentrations, mass removal rates for LAS generally were 2-3 times greater in laboratory column experiments than in the field tracer test. Under low oxygen conditions (<1 mg/L) only a fraction of the LAS mixture biodegraded in both laboratory and field experiments. Biodegradation rate constants for the continuous injection field test (0.002-0.08 day-1) were comparable to those estimated for a 3-h injection (pulsed) tracer test conducted under similar biogeochemical conditions, indicating that increasing the exposure time of aquifer sediments to LAS did not increase biodegradation rates.Transport and biodegradation of linear alkylbenzenesulfonate (LAS) in sewage-contaminated groundwater were investigated for a range of dissolved oxygen concentrations. Both laboratory column and an 80-day continuous injection tracer test field experiments were conducted. The rates of LAS biodegradation increased with increasing dissolved oxygen concentrations and indicated the preferential biodegradation of the longer alkyl chain LAS homologues (i.e., C12 and C13) and external isomers (i.e., 2- and 3-phenyl). However, for similar dissolved oxygen concentrations, mass removal rates for LAS generally were 2-3 times greater in laboratory column experiments than in the field tracer test. Under low oxygen conditions (<1 mg/L) only a fraction of the LAS mixture biodegraded in both laboratory and field experiments. Biodegradation rate constants

  13. A comparison of InVivoStat with other statistical software packages for analysis of data generated from animal experiments.

    PubMed

    Clark, Robin A; Shoaib, Mohammed; Hewitt, Katherine N; Stanford, S Clare; Bate, Simon T

    2012-08-01

    InVivoStat is a free-to-use statistical software package for analysis of data generated from animal experiments. The package is designed specifically for researchers in the behavioural sciences, where exploiting the experimental design is crucial for reliable statistical analyses. This paper compares the analysis of three experiments conducted using InVivoStat with other widely used statistical packages: SPSS (V19), PRISM (V5), UniStat (V5.6) and Statistica (V9). We show that InVivoStat provides results that are similar to those from the other packages and, in some cases, are more advanced. This investigation provides evidence of further validation of InVivoStat and should strengthen users' confidence in this new software package.

  14. Cosmological results from the Planck space mission and their comparison with data from the WMAP and BICEP2 experiments

    NASA Astrophysics Data System (ADS)

    Verkhodanov, O. V.

    2016-01-01

    We review basic results from the European Space Agency's Planck space mission, which are of crucial significance to understanding the origin and evolution of the Universe. The main stages of astrophysical and cosmological data processing pipelines are considered. The Planck results are compared with the data from the NASA WMAP (Wilkinson Microwave Anisotropy Probe) space mission and the BICEP2 (Background Imaging of Cosmic Extragalactic Polarization 2) experiment.

  15. PHITS simulations of the Protective curtain experiment onboard the Service module of ISS: Comparison with absorbed doses measured with TLDs

    NASA Astrophysics Data System (ADS)

    Ploc, Ondřej; Sihver, Lembit; Kartashov, Dmitry; Shurshakov, Vyacheslav; Tolochek, Raisa

    2013-12-01

    "Protective curtain" was the physical experiment onboard the International Space Station (ISS) aimed on radiation measurement of the dose - reducing effect of the additional shielding made of hygienic water-soaked wipes and towels placed on the wall in the crew cabin of the Service module Zvezda. The measurements were performed with 12 detector packages composed of thermoluminescent detectors (TLDs) and plastic nuclear track detectors (PNTDs) placed at the Protective curtain, so that they created pairs of shielded and unshielded detectors.

  16. Lessons learned with the Active Phasing Experiment: comparison of four optical phasing sensors on a segmented Very Large Telescope

    NASA Astrophysics Data System (ADS)

    Gonte, F.; Surdej, I.

    The adaptive optics capabilities are strongly limited by the quality of the phasing of the primary mirror of the extremely large telescope. Up to date, the Keck telescopes are the only segmented telescope phased with a quality enabling the application of adaptive optics. The Active Phasing Experiment has been installed at the Namyth focus of the Very Large Telescope Melipal during the last 6 months. Its purpose is to understand and compare different technological concepts for an optical phasing sensor dedicated to the European Extremely Large Telescope. The pupil of the telescope is segmented in 61 hexagonal segments by projecting it on an Active Segmented Mirror. The ASM is controlled by a dual wavenlength interferometer made by Fogale Nanotech with a nanometric precision. The segmented pupil is distributed in parallel to four optical phasing sensors. They are a pyramid sensor, a curvature sensor, a phase filtering sensor and a ShackHartmann sensor. They have been developed respectively by Istituto Nazionale di Astrofisica in Florenze, Instituto Astrofisica Canarias in Tenerife, Laboratoire d'Astrophysique de Marseille and ESO. The global behaviour of the optical phasing sensors will be described and preliminary results of the Active Phasing Experiments obtained on sky will be explained. The extrapolation of the results to the EELT and the potential consequences for the adaptive optics will be given. The Active Phasing Experiment has been financed by the European Union and the European Southern Observatory via the Sixth European Union Framework Program for Research and Technological Development under the contract number 011863.

  17. Understanding how deployment experiences change over time: Comparison of female and male OEF/OIF and Gulf War veterans.

    PubMed

    Fox, Annie B; Walker, Brian E; Smith, Brian N; King, Daniel W; King, Lynda A; Vogt, Dawne

    2016-03-01

    Despite increased attention to the evolving nature of war, the unique challenges of contemporary deployment, and women's changing role in warfare, few studies have examined differences in deployment stressors across eras of service or evaluated how gender differences in deployment experiences have changed over time. Using data collected from two national survey studies, we examined war cohort and gender differences in veterans' reports of both mission-related and interpersonal stressors during deployment. Although Operation Enduring Freedom and Operation Iraqi Freedom veterans reported more combat experiences and greater preparedness for deployment compared to Gulf War veterans, Gulf War veterans reported higher levels of other mission-related stressors, including difficult living and working environment, perceived threat, and potential exposure to nuclear, biological, and chemical weapons. Gender differences also emerged, with men reporting greater exposure to mission-related stressors and women reporting higher levels of interpersonal stressors. However, the size and nature of gender differences did not differ significantly when comparing veterans of the two eras. By understanding how risk factors for PTSD differ based on war era and gender, veterans' experiences can be better contextualized.

  18. Auditory perception of temporal order: A comparison between tonal language speakers with and without non-tonal language experience.

    PubMed

    Bao, Yan; Fang, Yuan; Yang, Taoxi; Wang, Lingyan; Szymaszek, Aneta; Szelag, Elzbieta

    2014-01-01

    It has been shown recently that temporal order perception is modulated by language environments. The present study focused on the specific question whether a secondary language experience influences temporal order perception by comparing the temporal order thresholds (TOTs) between Chinese subjects with and without a secondary non-tonal language (i.e., English) experience. Besides monaurally presented paired clicks, binaurally presented two different types of tone pairs were used in order to better capture a potential difference between tonal and non-tonal languages. The results showed a non-significant language effect on monaurally presented click TOTs, but a significant language effect for binaurally presented tone TOTs. Compared to click performance, Chinese subjects without English proficiency demonstrated a significantly lower TOT only for close frequency tone pairs, while Chinese subjects with English proficiency demonstrated lower TOTs for both close frequency and distant frequency tone pairs. These results confirm on the one hand a common and language independent temporal mechanism for perceiving the order of two monaurally presented stimuli, and indicate on the other hand specific mechanisms of neuronal plasticity for perceiving the order of frequency-related auditory stimuli for tonal language speakers with or without a secondary non-tonal language experience.

  19. The challenge of on-tissue digestion for MALDI MSI- a comparison of different protocols to improve imaging experiments.

    PubMed

    Diehl, Hanna C; Beine, Birte; Elm, Julian; Trede, Dennis; Ahrens, Maike; Eisenacher, Martin; Marcus, Katrin; Meyer, Helmut E; Henkel, Corinna

    2015-03-01

    Mass spectrometry imaging (MSI) has become a powerful and successful tool in the context of biomarker detection especially in recent years. This emerging technique is based on the combination of histological information of a tissue and its corresponding spatial resolved mass spectrometric information. The identification of differentially expressed protein peaks between samples is still the method's bottleneck. Therefore, peptide MSI compared to protein MSI is closer to the final goal of identification since peptides are easier to measure than proteins. Nevertheless, the processing of peptide imaging samples is challenging due to experimental complexity. To address this issue, a method development study for peptide MSI using cryoconserved and formalin-fixed paraffin-embedded (FFPE) rat brain tissue is provided. Different digestion times, matrices, and proteases were tested to define an optimal workflow for peptide MSI. All practical experiments were done in triplicates and analyzed by the SCiLS Lab software, using structures derived from myelin basic protein (MBP) peaks, principal component analysis (PCA) and probabilistic latent semantic analysis (pLSA) to rate the experiments' quality. Blinded experimental evaluation in case of defining countable structures in the datasets was performed by three individuals. Such an extensive method development for peptide matrix-assisted laser desorption/ionization (MALDI) imaging experiments has not been performed so far, and the resulting problems and consequences were analyzed and discussed.

  20. Simulation of real-gas effects on pressure distributions for aeroassist flight experiment vehicle and comparison with prediction

    NASA Technical Reports Server (NTRS)

    Micol, John R.

    1992-01-01

    Pressure distributions measured on a 60 degree half-angle elliptic cone, raked off at an angle of 73 degrees from the cone centerline and having an ellipsoid nose (ellipticity equal to 2.0 in the symmetry plane) are presented for angles of attack from -10 degrees to 10 degrees. The high normal shock density ratio aspect of a real gas was simulated by testing in Mach 6 air and CF sub 4 (density ratio equal to 5.25 and 12.0, respectively). The effects of Reynolds number, angle of attack, and normal shock density ratio on these measurements are examined, and comparisons with a three dimensional Euler code known as HALIS are made. A significant effect of density ratio on pressure distributions on the cone section of the configuration was observed; the magnitude of this effect decreased with increasing angle of attack. The effect of Reynolds number on pressure distributions was negligible for forebody pressure distributions, but a measurable effect was noted on base pressures. In general, the HALIS code accurately predicted the measured pressure distributions in air and CF sub 4.

  1. Intermolecular potential of the O2-O2 dimer. An ab initio study and comparison with experiment.

    PubMed

    Hernández-Lamoneda, Ramón; Bartolomei, Massimiliano; Hernández, Marta I; Campos-Martínez, José; Dayou, Fabrice

    2005-12-22

    Accurate intermolecular potentials for the lowest three multiplet states of O2-O2 dimer have been produced on the basis of ab initio calculations. The quintet potential was taken from previous highly correlated CCSD(T) calculations. In this work, we perform MRCI calculations, with large basis sets including bond functions, of the singlet and triplet states, which are of multireference character. As expected the size inconsistency and lack of higher order excitations limit the accuracy of the MRCI potentials specifically in describing the long range interactions. We show that the Heisenberg Hamiltonian provides an accurate representation of the exchange interactions in this system and this enables us to combine the accurate CCSD(T) potentials with the MRCI spin-exchange parameter to obtain accurate singlet and triplet potentials. The reliability of these potentials is tested by computing integral cross sections and comparing them with the detailed experimental study of the Perugia group, with excellent results. More interestingly, comparison with the experimentally derived potential shows important discrepancies for some angular orientations including that corresponding with the global minima, indicating the need for further work, both theoretical and experimental, to clarify their origin.

  2. Transmission loss of multilayer panels containing a fluid using progressive wave model: Comparison with impedance progressive model and experiments

    NASA Astrophysics Data System (ADS)

    Mohammadi, N.; Mahjoob, M. J.

    2009-04-01

    The progressive wave model is applied to calculate transmission loss (TL) of triple layer panels. Theoretical values are then compared with impedance progressive model and experimental results. The triple layer panel comprises two solid layers with a middle layer of air or liquid. An impedance tube is employed to measure the TL values experimentally. The comparison of the two analytical models shows that the results of both models are relatively close. However, the progressive wave model leads to slightly larger values for a wide range of frequencies. Also, for the case of an air middle layer, a shift of the resonances to higher frequencies is observed in the results of the progressive wave model. Computational results also demonstrate that applying a liquid middle layer (replacing air) significantly improves the performance of the acoustic panel particularly at frequencies below 4000 rad/s (640 Hz). Shifting resonance frequencies to higher frequencies is another advantage of incorporating the liquid layer. Good agreement was also found between theoretical and experimental results. To cite this article: N. Mohammadi, M.J. Mahjoob, C. R. Mecanique 337 (2009).

  3. Simulation studies of the Cl- + CH3I SN2 nucleophilic substitution reaction: comparison with ion imaging experiments.

    PubMed

    Zhang, Jiaxu; Lourderaj, Upakarasamy; Sun, Rui; Mikosch, Jochen; Wester, Roland; Hase, William L

    2013-03-21

    In the previous work of Mikosch et al. [Science 319, 183 (2008)], ion imaging experiments were used to study the Cl(-) + CH3I → ClCH3 + I(-) reaction at collision energies E(rel) of 0.39, 0.76, 1.07, and 1.9 eV. For the work reported here MP2(fc)/ECP/d direct dynamics simulations were performed to obtain an atomistic understanding of the experiments. There is good agreement with the experimental product energy and scattering angle distributions for the highest three E(rel), and at these energies 80% or more of the reaction is direct, primarily occurring by a rebound mechanism with backward scattering. At 0.76 eV there is a small indirect component, with isotropic scattering, involving formation of the pre- and post-reaction complexes. All of the reaction is direct at 1.07 eV. Increasing E(rel) to 1.9 eV opens up a new indirect pathway, the roundabout mechanism. The product energy is primarily partitioned into relative translation for the direct reactions, but to CH3Cl internal energy for the indirect reactions. The roundabout mechanism transfers substantial energy to CH3Cl rotation. At E(rel) = 0.39 eV both the experimental product energy partitioning and scattering are statistical, suggesting the reaction is primarily indirect with formation of the pre- and post-reaction complexes. However, neither MP2 nor BhandH/ECP/d simulations agree with experiment and, instead, give reaction dominated by direct processes as found for the higher collision energies. Decreasing the simulation E(rel) to 0.20 eV results in product energy partitioning and scattering which agree with the 0.39 eV experiment. The sharp transition from a dominant direct to indirect reaction as E(rel) is lowered from 0.39 to 0.20 eV is striking. The lack of agreement between the simulations and experiment for E(rel) = 0.39 eV may result from a distribution of collision energies in the experiment and/or a shortcoming in both the MP2 and BhandH simulations. Increasing the reactant rotational temperature

  4. Stress effects of noise in a field experiment in comparison to reactions to short term noise exposure in the laboratory.

    PubMed

    Ising, H; Michalak, R

    2004-01-01

    Reactions to noise-induced communication disturbance of 42 men during a seminar were investigated. Stress reactions with or without road traffic noise (Lm = 60 dBA) were compared. Traffic noise was played back via loudspeakers during one day in the seminar room. The following parameters were measured: Fatigue and mental tension by questionnaire; blood pressure and heart rate; excretion of adrenaline, noradrenaline and cAMP from the collected urine. The same subjects participated in a laboratory test where the blood pressure was measured during 5 minutes of rest and after 5 minutes of exposure to intermittent white noise (Lm=97 dBA). It was found that the noise in the field experiment caused psychological and physiological stress effects in half of the subjects. Increased mental tension was correlated to increases as well as decreases of the blood pressure. Systolic blood pressure reactions were stronger than the reactions of diastolic blood pressure. Noise sensitive subjects reacted stronger than the others. In the short-term laboratory test, systolic blood pressure increases were smaller than the diastolic increases. At the end of the 5 minutes noise exposure only the diastolic blood pressure increases were significant. There was no correlation between the blood pressure reactions in the two different noise exposure experiments. There existed a positive correlation between noise sensitivity and the systolic blood pressure increases during the seminar, whilst the correlation, between noise sensitivity and systolic blood pressure increases in the laboratory exposure, was negative. From these results we conclude that short-term noise exposure experiments do not provide information about the effects of long-term real life exposure to environmental noise. Potential health effects of chronic noise-induced disturbances of activities are discussed.

  5. The Mechanics of Coulomb Wedges: Comparison Between a Numerical Model (Boundary Element Method) and a Sand-Box Experiment.

    NASA Astrophysics Data System (ADS)

    Del Castello, M.; Cooke, M.

    2006-12-01

    Fold and thrust belts have been successfully modelled using either physical or numerical methods in recent years. The two methods have well-known advantages and drawbacks for investigating contractional processes. In this work we have applied the Boundary Element Method code in order to closely reproduce successive snapshots of deformation accumulated within a sand-box experiment. Our numerical models provide a quantitative mechanical analysis of the deformation observed in analogue models of non-cohesive Coulomb wedges during an underthrusting/accretion transition. Model results show that the total work done by the contracting wedge increases during the underthrusting stage up to a critical value when the propagation of a frontal thrust significantly reduces the work required for further deformation. This transition occurs when the energetic cost of developing a new forethrust is less than the benefit of growing this new fault. The elastic numerical model predicts the location of the maximum shear stress on the basal dècollement just prior to the propagation of the sole thrust as well as the energetically most viable position for the nucleation of new forethrust ramp. These positions do not coincide. Furthermore, the forethrust within the sandbox experiment develops at the energetically favoured position rather than the location of greatest shear stress suggesting that the new thrust ramps develop first ahead and then link down and backward to the propagating basal dècollement. As a result, the most efficient location for a new thrust ramp is where gravitational, frictional, internal and propagation work terms are optimally combined. The trade-off between the dominant frictional and internal work terms is fuelled by overburden weight, which reduces slip on thrust ramps until the internal work stored in the surrounding deforming material reaches a critical value. The correlation of our numerical results with analogue experiments validates use of the principle of

  6. 40-Gbps vestigial sideband half-cycle Nyquist subcarrier modulation transmission experiment and its comparison with orthogonal frequency division multiplexing

    NASA Astrophysics Data System (ADS)

    Liu, Na; Chen, Xue; Ju, Cheng; Hui, Rongqing

    2014-09-01

    We experimentally demonstrate the superior performance of a 40-Gbps 16-QAM half-cycle Nyquist subcarrier modulation (SCM) transmission over a 100-km uncompensated standard single-mode fiber using dual-drive Mach-Zehnder modulator-based vestigial sideband intensity modulation and direct detection. The impact of modulator chirp on the system performance is experimentally evaluated. This Nyquist-SCM technique is compared with optical orthogonal frequency division multiplexing in both back-to-back and 100-km transmission experiments, and the results show that the Nyquist system has a better performance.

  7. Comparison between large area photo-multiplier tubes at cryogenic temperature for neutrino and rare event physics experiments

    NASA Astrophysics Data System (ADS)

    Falcone, A.; Bertoni, R.; Boffelli, F.; Bonesini, M.; Cervi, T.; Menegolli, A.; Montanari, C.; Prata, M. C.; Rappoldi, A.; Raselli, G. L.; Rossella, M.; Spanu, M.; Torti, M.; Zani, A.

    2015-07-01

    An evaluation of the behavior of three large cathode area photo-multiplier tubes, Hamamatsu R5912 Mod and R5912-02 Mod, and ETL 9357 KFLB, was carried out both at room and cryogenic temperature, using a 405 nm light source. The main electrical and optical features of the devices were studied; the obtained results were compared with the characteristics of the ETL 9357 FLA tubes, used in the ICARUS experiment. Tubes were also studied as a function of the Earth's magnetic field and an evaluation of the quantum efficiency was made in the vacuum ultraviolet light region.

  8. Comparison of SSM/I measurements to numerically-simulated cloud and precipitation during ERICA. [Experiment for Rapidly Intesifying Cyclones

    NASA Technical Reports Server (NTRS)

    Perkey, Donald J.; Robertson, Franklin R.; Lapenta, William M.; Cohen, Charles

    1990-01-01

    The relationship between the moisture fields and the cyclone event that occurred on January 4-5, 1989 over Atlantic was investigated using preliminary 140-km and 70-km simulations of this cyclone, generated by a 3D version of the Drexel LAMPS, along with digital imagery from the SSM/I sensor. As the source of data, a sounding data set was obtained from the Experiment for Rapidly Intensifying Cyclones over the Atlantic (ERICA) Data Center. It was found that the 70-km integration produces a realistic moisture and cloud field as judged against passive microwave and IR imagery.

  9. Comparison of velocity and temperature time series data analysis in experiments on the thermally driven rotating annulus

    NASA Astrophysics Data System (ADS)

    von Larcher, Thomas; Harlander, Uwe; Alexandrov, Kiril; Wang, Yongtai

    2010-05-01

    The model of the differentially heated, rotating cylindrical gap filled with a fluid is since more than four decades extensively used for laboratory experiments of baroclinic wave interactions, and a number of data acquisition techniques are applied e.g. to unhide regular waves of different zonal wave number, to better understand the transition to the quasi-chaotic regime, and to reveal the underlying dynamical processes of complex wave flows. In our experiments presented here, we make use of non-intrusive measurement techniques of a quite different nature. While the high accurate Laser-Doppler-Velocimetry (LDV ) is used for measurements of the radial velocity component at equidistant azimuthal positions, a high sensitive thermographic camera, which resolution allows for resolving fine scale structures, measures the surface temperature field. Both sets of time series data are analyzed by using multivariate statistical techniques. While the LDV data sets are studied by applying the Multi-Channel Singular Spectrum Analysis (M - SSA), the temperature data sets are analyzed by applying the Empirical Orthogonal Functions (EOF ). In addition, the temperature data are processed in a way to become comparable to the LDV data, i.e. reducing the size of the data set in such a manner that the temperature measurements would imaginary be performed at equidistant azimuthal positions only. This approach initially results in a great loss of information. But applying the M - SSA to the reduced temperature data sets enable us not only to compare the data analysis methods but also to reclassify the results yielded with the LDV data analysis. The measurements are performed at particular parameter points, where our former studies show that kinds of complex wave patterns occur [1, 2]. For example, we found a dominant and a weak mode in the 3-4 wave transition region. This finding confirms earlier ideas on wave dispersion in transition regions between regular waves. Increasing the annulus

  10. Simulation of large particle transport near the surface under stable conditions: comparison with the Hanford tracer experiments

    NASA Astrophysics Data System (ADS)

    Kim, Eugene; Larson, Timothy

    A plume model is presented describing the downwind transport of large particles (1-100 μm) under stable conditions. The model includes both vertical variations in wind speed and turbulence intensity as well as an algorithm for particle deposition at the surface. Model predictions compare favorably with the Hanford single and dual tracer experiments of crosswind integrated concentration (for particles: relative bias=-0.02 and 0.16, normalized mean square error=0.61 and 0.14, for the single and dual tracer experiments, respectively), whereas the US EPA's fugitive dust model consistently overestimates the observed concentrations at downwind distances beyond several hundred meters (for particles: relative bias=0.31 and 2.26, mean square error=0.42 and 1.71, respectively). For either plume model, the measured ratio of particle to gas concentration is consistently overestimated when using the deposition velocity algorithm of Sehmel and Hodgson (1978. DOE Report PNL-SA-6721, Pacific Northwest Laboratories, Richland, WA). In contrast, these same ratios are predicted with relatively little bias when using the algorithm of Kim et al. (2000. Atmospheric Environment 34 (15), 2387-2397).

  11. Comparison of measured soft x-ray drive with shock and capsule implosion velocity for ignition tuning experiments on NIF

    NASA Astrophysics Data System (ADS)

    Kline, J.; Callahan, D.; Meezan, N.; Glenzer, S.; MacKinnon, A.; Dixit, S.; Kyrala, G.; Widmann, K.; Robey, H.; Clark, D.; Jones, O.; Hicks, D.; Celliers, P.; Farley, D.; Town, R.; Kalantar, D.; Dewald, E.; Moore, A.; Olson, R.; Doeppner, T.; Moody, J.; Ralph, J.; Thomas, C.; Landen, O.; Edwards, M.

    2011-10-01

    Indirect drive inertial confinement fusion experiments use high-Z hohlraums to convert laser energy to soft x-ray energy. The soft x-rays then drive the capsule via material ablation to compress the fuel payload and heat the central hot spot to initiate ignition. To achieve the highest fuel compression, a shaped radiation drive is used launching multiple shocks timed minimizes fuel entropy. The strength and velocity of these shocks depend directly on the radiation drive. The main laser pulse is then used to drive the implosion such that the PdV work can heat the central core to fusion conditions. To diagnose the soft x-ray drive in the hohlraum, Dante, an 18 channel soft x-ray spectrometer, measures the flux escaping the laser entrance hole. Measurements of this flux are used to assess the conditions for the capsule implosion. In this presentation, we will examine correlations between the soft x-ray measurements and shock velocity, as well as implosion velocity for recent ignition tuning experiments on NIF.

  12. The Perceived Effects of Condoms on Sexual Experience: A Comparison of Older Hispanic and Non-Hispanic Men.

    PubMed

    Jones, Sande Gracia; Fenkl, Eric A; Patsdaughter, Carol A; Chadwell, Katherine; Valdes, Beatriz

    2015-01-01

    Heterosexual transmission of HIV and other sexually transmitted diseases (STDs) is increasing in older adult populations around the world. This study compares Hispanic and non-Hispanic men ages 50 years and older currently using prescribed erectile dysfunction medications in relation to their perception of the effect of condoms on sexual experience. A sample of 86 men (40 Hispanic and 46 non-Hispanic men) ages 50-79 years completed the 10-item Effect on Sexual Experience (ESE) subscale. Although there was no difference between the 2 groups on the subscale mean score, t(84) = 1.449, p = .151, analysis of the subscale items found 1 item that was significantly different (p = .005) between the 2 groups, although this difference could have been related to different perceptions of the word disgusting. Hispanic men were also less concerned than non-Hispanic men about condom-related loss of erection. This study adds to the literature on HIV and STD prevention for older Hispanic/Latinos.

  13. The issue of multiple univariate comparisons in the context of neuroelectric brain mapping: an application in a neuromarketing experiment.

    PubMed

    Vecchiato, G; De Vico Fallani, F; Astolfi, L; Toppi, J; Cincotti, F; Mattia, D; Salinari, S; Babiloni, F

    2010-08-30

    This paper presents some considerations about the use of adequate statistical techniques in the framework of the neuroelectromagnetic brain mapping. With the use of advanced EEG/MEG recording setup involving hundred of sensors, the issue of the protection against the type I errors that could occur during the execution of hundred of univariate statistical tests, has gained interest. In the present experiment, we investigated the EEG signals from a mannequin acting as an experimental subject. Data have been collected while performing a neuromarketing experiment and analyzed with state of the art computational tools adopted in specialized literature. Results showed that electric data from the mannequin's head presents statistical significant differences in power spectra during the visualization of a commercial advertising when compared to the power spectra gathered during a documentary, when no adjustments were made on the alpha level of the multiple univariate tests performed. The use of the Bonferroni or Bonferroni-Holm adjustments returned correctly no differences between the signals gathered from the mannequin in the two experimental conditions. An partial sample of recently published literature on different neuroscience journals suggested that at least the 30% of the papers do not use statistical protection for the type I errors. While the occurrence of type I errors could be easily managed with appropriate statistical techniques, the use of such techniques is still not so largely adopted in the literature.

  14. Does Mindset Intervention Predict Students' Daily Experience in Classrooms? A Comparison of Seventh and Ninth Graders' Trajectories.

    PubMed

    Schmidt, Jennifer A; Shumow, Lee; Kackar-Cam, Hayal Z

    2017-03-01

    One's beliefs about whether ability is fixed or malleable-also known as fixed or growth mindset-can impact academic outcomes. This quasi-experimental study investigated effects of a six-week classroom intervention targeting growth mindset on students' daily quality of experience in science classrooms. Seventh grade (N = 370) and 9th grade (N = 356) students (50 % female, 61 % Hispanic) were randomly assigned by classroom to either a mindset intervention condition or content writing task condition. Students provided self-reports on multiple aspects of their daily classroom experience 11 times across the school year. Hierarchical linear growth models indicate that 7th and 9th grade students who were not exposed to the mindset intervention showed declines in perceived control skill, interest, and learning. In contrast, 9th graders in the mindset intervention reported increased control and interest, and maintained constant levels in skill and learning. Similar effects were not observed among 7th graders. The results are discussed in terms of implications for future research and optimal developmental periods for mindset intervention.

  15. Operational experience of electronic active personal dosemeter and comparison with CaSo4:Dy TL dosemeter in Indian PHWR.

    PubMed

    Singh, Vishwanath P; Managanvi, S S; Bihari, R R; Bhat, H R

    2013-01-01

    Direct reading dosemeter has been used for day-to-day radiation exposure control and management for last four decades in Indian nuclear power plants (NPPs). Recently new real time, alarm and pre-alarm on equivalent dose/dose rate, storage of dose/dose rate and maximum dose rate, user-friendly electronic active personal dosemeter (APD) has been implemented into practice for the first time at Kaiga Atomic Power Station-3&4,  of Indian NPPs. The dosemeter showed tolerance level (L) 0.1085±0.0450 compared with 0.1869±0.0729 (average±SD) for CaSO4:Dy, TL dosemeter, having narrow range trumpet curve, nil electromagnetic interference. Records of >29 000 for APD and TL dosemeter were analysed for comparasion of the measurement of the individual dose. APD followed general acceptance rule of ±25 % for dose >1 mSv. Monthly Station collective dose by TL dosemeters and APD for normal reactor operation as well as outage are found in good agreement. Operational experiences and statistical analysis support that an APD dosemeter is reasonably equivalent to CaSO4:Dy TL dosemeter. The accuracy, reproducibility and repeatability of the measurement of radiation for (137)Cs are comparable with CaSO4:Dy, TL dosemeter. Operational experience of APD during the normal operation as well as outage showed as one of the best ALARA tool for occupational dose monitoring, control, management and future outage planning.

  16. Characterization and comparison of seismic signals emitted during field scale sheer box experiments and artificially induced landslides

    NASA Astrophysics Data System (ADS)

    Yfantis, Georgios; Martinez Carvajal, Hernan Eduardo; Pytharouli, Stella; Lunn, Rebecca

    2014-05-01

    The identification and detection of landslide induced seismic signals, recorded by deployed seismometers on active landslides has been the subject of many studies. The most commonly faced problem is the uncertainty in identifying which of the recorded signals are representing a movement or a failure in the landslide's body. In this paper we present two novel experimental campaigns; 1) field scale laboratory experiments of a 65cm diameter sheer box, 2) artificially induced failure of two, two-meter high vertical soil slopes. Using a field scale sheer box we recorded seismic signals emitted during soil slippage events, a phenomenon observed at a landslide's failure plain. This was implemented by displacing, a few centimeters at a time (1-10cm), a concrete cylinder filled with soil along a corridor free from vegetation. The field scale sheer box methodology allows control over a large number of parameters that affect a landslide. For example, it is possible to control soil saturation thus simulating different rain events or control the stress field on the soil's slippage surface simulating displacement events at different depths. More than 40 displacement events were induced under four different loading conditions between 472kg to 829kg. All soil slippage events were recorded above the levels of background seismic noise. Repetition of the methodology under the same experimental conditions resulted in similar seismic signals allowing us to define a 'characteristic seismic response' for soils. In the second experimental campaign, two controlled landslides were experimentally induced by increasing the vertical load on top of a 2m soil scarp. We were able to detect from 1 to 10 centimeter wide crack propagations and displacements, and approximately 20x20x10cm to 100x50x20cm block failure events based on microseismic recordings, field notes, video recordings and displacement measurements of the landslide's crown that failed during the experiments. Direct correlation

  17. Direct dynamics simulations of the product channels and atomistic mechanisms for the OH(-) + CH3I reaction. Comparison with experiment.

    PubMed

    Xie, Jing; Sun, Rui; Siebert, Matthew R; Otto, Rico; Wester, Roland; Hase, William L

    2013-08-15

    Electronic structure and direct dynamics calculations were used to study the potential energy surface and atomic-level dynamics for the OH(-) + CH3I reactions. The results are compared with crossed molecular beam, ion imaging experiments. The DFT/B97-1/ECP/d level of theory gives reaction energetics in good agreement with experiment and higher level calculations, and it was used for the direct dynamics simulations that were performed for reactant collision energies of 2.0, 1.0, 0.5, and 0.05 eV. Five different pathways are observed in the simulations, forming CH3OH + I(-), CH2I(-) + H2O, CH2 + I(-) + H2O, IOH(-) + CH3, and [CH3--I--OH](-). The SN2 first pathway and the proton-transfer second pathway dominate the reaction dynamics. Though the reaction energetics favor the SN2 pathway, the proton-transfer pathway is more important except for the lowest collision energy. The relative ion yield determined from the simulations is in overall good agreement with experiment. Both the SN2 and proton-transfer pathways occur via direct rebound, direct stripping, and indirect mechanisms. Except for the highest collision energy, 70-90% of the indirect reaction for the SN2 pathway occurs via formation of the hydrogen-bonded OH(-)---HCH2I prereaction complex. For the proton-transfer pathway the indirect reaction is more complex with the roundabout mechanism and formation of the OH(-)---HCH2I and CH2I(-)---HOH complexes contributing to the reaction. The majority of the SN2 reaction is direct at 2.0, 1.0, and 0.5 eV, dominated by stripping. At 0.05 eV the two direct mechanisms and the indirect mechanisms have nearly equal contributions. The majority of the proton-transfer pathway is direct stripping at 2.0, 1.0, and 0.5 eV, but the majority of the reaction is indirect at 0.05 eV. The product relative translational energy distributions are in good agreement with experiment for both the SN2 and proton-transfer pathways. For both, direct reaction preferentially transfers the product

  18. The oxidized soot surface: theoretical study of desorption mechanisms involving oxygenated functionalities and comparison with temperature programed desorption experiments.

    PubMed

    Barco, Gianluca; Maranzana, Andrea; Ghigo, Giovanni; Causà, Mauro; Tonachini, Glauco

    2006-11-21

    The desorption mechanism for oxygenated functionalities on soot is investigated by quantum mechanical calculations on functionalized polycyclic aromatic hydrocarbon (PAH) models and compared with recently published temperature programed desorption-mass spectrometry results. Substituents on PAHs of increasing size (up to 46 carbon atoms in the parent PAH) are chosen to reproduce the local features of an oxidized graphenic soot platelet. Initially, the study is carried out on unimolecular fragmentation (extrusion, in some cases) processes producing HO, CO, or CO2, in model ketones, carboxylic acids, lactones, anhydrides, in one aldehyde, one peroxyacid, one hydroperoxide, one secondary alcohol, and one phenol. Then, a bimolecular process is considered for one of the carboxylic acids. Furthermore, some cooperative effect which can take place by involving two vicinal carboxylic groups (derived from anhydride hydrolysis) is investigated for other four bifunctionalized models. The comparison between the computed fragmentation (desorption) barriers for the assessed mechanisms and the temperature at which maxima occur in TPD spectra (for HO, CO, or CO2 desorption) offers a suggestion for the assignment of these maxima to specific functional groups, i.e., a key to the description of the oxidized surface. Notably, the computations suggest that (1) the desorption mode from a portion of a graphenic platelet functionalized by a carboxylic or lactone groups is significantly dependent from the chemical and geometric local environment. Consequently, we propose that (2) not all carboxylic groups go lost at the relatively low temperatures generally stated, and (3) lactone groups can be identified as producing not only CO2 but also CO.

  19. Comparison of particle-in-cell simulation with experiment for the transport system of the superconducting electron cyclotron resonance ion source VENUS

    SciTech Connect

    Todd, D.S.; Leitner, D.; Leitner, M.; Lyneis, C.M.; Qiang, J.; Grote, D.P.

    2006-03-15

    The three-dimensional, particle-in-cell code WARP has been enhanced to allow end-to-end beam dynamics simulations of the VENUS beam transport system from the extraction region, through a mass-analyzing magnet, and up to a two-axis emittance scanner. This article presents the first results of comparisons between the simulation and experimental data. A helium beam (He{sup +} and He{sup 2+}) is chosen as an initial comparison beam due to its simple mass spectrum. Although a number of simplifications are made for the initial extracted beam, aberration characteristics appear in simulations that are also present in experimental phase-space current-density measurements. Further, measurements of phase-space tilt indicate that simulations must have little or no space-charge neutralization along the transport system to best agree with experiment. In addition, recent measurements of triangular beam structure immediately after the source are presented. This beam structure is related to the source magnetic confinement fields and will need to be taken into account as the initial beam approximations are lifted.

  20. Lava-snow interactions at Tolbachik 2012-13 eruption: comparison to recent field observations and experiments

    NASA Astrophysics Data System (ADS)

    Edwards, B. R.; Belousov, A.; Belousova, M.; Izbekov, P. E.; Bindeman, I. N.; Gardeev, E.; Muravyev, Y. D.; Melnikov, D.

    2013-12-01

    More than a dozen volcanic eruptions in the past twenty years have produced lava interaction with snow or ice, some of which have produced damaging floods/lahars. However, the factors controlling melting during lava-snow/ice interactions is not well understood. Recent observations from the presently ongoing eruption at Tolbachik, Kamchatka confirm some general observations from large-scale experiments, and recent eruptions (2010 Fimmvorduhals; Edwards et al, 2012), but also show new types of behavior not before described. The new observations provide further constraints on heat transfer between ice/snow and three different lava morphologies: ';a'a, pahoehoe, and toothpaste. ';A'a flows at Tolbachik commonly were able to travel over seasonal snow cover (up to 4 m thick), especially where the snow was covered by tephra within 1.5 km of the vent area. Locally, heated meltwater discharge events issued from beneath the front of advancing lava, even though snow observation pits dug in front of advancing ';a'a flows also showed that in some areas melting was not as extensive. Once, an ';a'a flow was seen to collapse through snow, generating short-lived phreatomagmatic/phreatic activity. Closer to the vent, pahoehoe flow lobes and sheet flows occasionally spilled over onto snow and were able to rapidly transit snow with few obvious signs of melting/steam generation. Most of these flows did melt through basal snow layers within 24 hours however. We were also able to closely observe ';toothpaste' lava flows ';intruding' into snow in several locations, including snow-pits, and to watch it pushing up through snow forming temporary snow domes. Toothpaste lava caused the most rapid melting and most significant volumes of steam, as the meltwater drained down into the intruding lava. Behaviour seen at Tolbachik is similar to historic (e.g., Hekla 1947; Einarrson, 1949) and recent observations (e.g. Fimmvorduhals), as well as large-scale experiments (Edwards et al., 2013). While

  1. Liver cirrhosis grading Child-Pugh class B: a Goliath to challenge in laparoscopic liver resection?—prior experience and matched comparisons

    PubMed Central

    Liang, Xiao; Yu, Tunan; Liang, Yuelong; Jing, Renan; Jiang, Wenbing; Li, Jianbo; Ying, Hanning

    2015-01-01

    Background Laparoscopic hepatectomy (LH) is highly difficult in the background of liver cirrhosis. In this case series, we aimed to summarize our prior experience of LH in liver cirrhosis grading Child-Pugh class B. Methods In the LH database of Sir Run Run Shaw Hospital in Zhejiang, China, patients who were pathologically diagnosed with cirrhosis and graded as Child-Pugh class B or C were reviewed. Results Five patients grading Child B were included. There was no Child C case in our LH database. For included cases, median blood loss (BL) was 800 (range, 240-1,000) mL, median operative time was 135 (range, 80-170) minutes, and median length of hospital stay was 9 (range, 7-15) days. Forty percent (2/5) of patients was converted to open. The postoperative complication (PC) rate was 20.0% (1/5). When these Child B cases were compared with Child A cases undergoing LH, there was no statistical significance in BL, complication rate, operative time, open rate and hospital stay (HS) (P>0.05). This finding was confirmed by two ways of matched comparisons (a 1:2 comparison based on age and gender, and a 1:1 propensity score matching). Conclusions Although relevant literatures had suggested feasibility of LH in cirrhotic cases grading Child A, this study was the first one to discuss the value of LH in Child B cases. Our prior experience showed that in selected patients, LH in Child B patients had the potential to be as safe as in Child A cases. The efficacy of LH in Child C patients needs further exploration. PMID:26734623

  2. A comparison of theory and experiment for coupled rotor-body stability of a hingeless rotor model in hover

    NASA Technical Reports Server (NTRS)

    Bousman, William G.

    1988-01-01

    Three cases were selected for correlation from an experiment that examined the aeromechanical stability of a small-scale model of a hingeless rotor and fuselage in hover. The first case examined the stability of a configuration with 0 degree blade pitch so that coupling between dynamic modes was minimized. The second case was identical to the first except the blade pitch was set to 9 degrees which provides flap-lag coupling of the rotor modes. The third case had 9 degrees of blade pitch and also included negative pitch-lag coupling, and therefore was the most highly coupled configuration. Analytical calculations were made by Bell Helicopter Textron, Boeing Vertol, Hughes Helicopters, Sikorsky Aircraft, the U.S. Army Aeromechanics Laboratory, and NASA Ames Research Center and compared to some or all of the experimental cases. Overall, the correlation ranged from very poor-to-poor to good.

  3. Shock recovery experiments in the range of 10 to 45 GPa - comparison of results of synthetic magnetite and terrestrial diabase

    NASA Astrophysics Data System (ADS)

    Kohout, T.; Pesonen, L.; Deutsch, A.; Honnermann, U.; Heikinheimo, E.

    2008-12-01

    Shock-induced changes in magnetic properties of rocks, minerals and meteorites play an important role in modelling the magnetic anomalies of impact structures (e.g. Vredefort), in interpretation of the magnetic anomalies of planetary bodies (e.g. Mars) and in understanding the paleomagnetic data of meteorites. To shed further light on these problems we report results of experimentally shocked samples of synthetic fine grained magnetite. We used cylindrical surface-polished discs (d 10 mm, h 4 mm) of the well characterized magnetite with SD-PSD grain size range. The magnetite powder was mixed with Al2O3 and sintered into disktype pellets. A series of shock recovery experiments from 10 to 45 GPa (nominal pressure) using a conventional high-explosive set-up with a steel (ARMCO) sample container, surrounded by a momentum trap of the identical material. As the samples were shocked inside the highly magnetic containers, the prevailing magnetic field was roughly five times higher than the ambient field. After the shock, the containers cooled down slowly to ambient temperatures. The estimated post-shock temperatures of the samples range from nearly ambient temperature (10 GPa) up to about 1400 K (45 GPa). Evaluating the "real" pressures reached in these experiments requires a model to account for the high porosity of the pellets. The porosity also affects significantly the post-shock temperature. Independent of the fact that pressure, shock- and post- shock tmperatures are not sufficiently constrained yet, the experiments form a well-characterized series of shocks with systematically increasing pressure. Surprisingly enough, the sample discs were not friable and could be removed by retaining shape largely unchanged. The shock induced changes in sample properties show, with the exception of the 45 GPa sample, with increasing shock pressure: 1. Reduction of bulk density and significant increase in porosity 2. Minor increase in magnetic susceptibility (10 GPa, 15 GPa and 45

  4. A study of small systems containing H and O atoms using nonlocal functionals: Comparison with ab initio and experiment

    SciTech Connect

    Seminario, J.M.

    1994-12-31

    Structures and energies have been calculated for HO, H{sub 2}O, O{sub 2}, HO{sub 2}, H{sub 2}O{sub 2}, and O{sub 3} molecules using the nonlocal functionals PW 86, PW 91, B-P86, and B-LYP with the goal of obtaining their atomization energies. Results were compared with those form highly correlated methods and experiment. It was found that all nonlocal functionals perform similarly to or better than correlated methods MP4 and QCI (using relatively equivalent basis sets). All nonlocal energies were self-consistently calculated using the optimized geometries for each functional. None of the results contain any empirical correction except those inherent to some of the functionals. Increasing the size of the basis set when using the nonlocal functionals does not lead to any significant improvement of the energies and surprisingly it worsens the results for one of the functionals.

  5. Large amplitude flutter of a low aspect ratio panel at low supersonic speeds comparison of theory and experiment

    NASA Technical Reports Server (NTRS)

    Ventres, C. S.; Kang, C. K.

    1973-01-01

    Flutter boundaries, as well as flutter limit cycle amplitudes, frequencies and stresses were computed for a panel of length-width ratio 4.48 exposed to applied in-plane and transverse loads. The Mach number range was 1.1 to 1.4. The method used involved direct numerical integration of modal equations of motion derived from the nonlinear plate equations of von Karman, coupled with linearized potential flow aerodynamic theory. The flutter boundaries agreed reasonably well with experiment, except when the in-plane loading approached the buckling load. Structural damping had to be introduced, to produce frequencies comparable to the experimental values. Attempts to compute panel deflections or stress at a given point met with limited success. There is some evidence, however, that deflection and stress maxima can be estimated with somewhat greater accuracy.

  6. The MATROSHKA experiment: results and comparison from extravehicular activity (MTR-1) and intravehicular activity (MTR-2A/2B) exposure.

    PubMed

    Berger, Thomas; Bilski, Paweł; Hajek, Michael; Puchalska, Monika; Reitz, Günther

    2013-12-01

    Astronauts working and living in space are exposed to considerably higher doses and different qualities of ionizing radiation than people on Earth. The multilateral MATROSHKA (MTR) experiment, coordinated by the German Aerospace Center, represents the most comprehensive effort to date in radiation protection dosimetry in space using an anthropomorphic upper-torso phantom used for radiotherapy treatment planning. The anthropomorphic upper-torso phantom maps the radiation distribution as a simulated human body installed outside (MTR-1) and inside different compartments (MTR-2A: Pirs; MTR-2B: Zvezda) of the Russian Segment of the International Space Station. Thermoluminescence dosimeters arranged in a 2.54 cm orthogonal grid, at the site of vital organs and on the surface of the phantom allow for visualization of the absorbed dose distribution with superior spatial resolution. These results should help improve the estimation of radiation risks for long-term human space exploration and support benchmarking of radiation transport codes.

  7. Adolescents' psychological response to the experience of community interpersonal violence: a cross-national and a cross-cultural comparison.

    PubMed

    Rosenthal, Beth Spenciner; Wilson, W Cody

    2006-01-01

    A comparative cross-national study investigating the level of experience with community interpersonal violence, level of psychological distress, and the relationship between exposure and distress among adolescents is presented. Participants were 617 first-year college students comprising African Americans and Jamaican Americans living in New York City, and Jamaicans living in Kingston, Jamaica. The three groups are similar in terms of age, gender, educational level, and race; they differ in location of residence, culture, and immigration status. Location of residence is related to exposure; immigration status is related to distress; but culture is not related to vulnerability when exposed. The effect size of the relationship between exposure and distress appears to be robust across variations in culture, amount of exposure, and level of distress.

  8. Comparison of the hemodynamic response to different visual stimuli in single-event and block stimulation fMRI experiments.

    PubMed

    Janz, C; Schmitt, C; Speck, O; Hennig, J

    2000-11-01

    Experiments with three different types of basic visual stimulation were performed to compare cortical activation in single-event and block trials. Independent of the stimulation paradigm, the single-event presentation leads to highly consistent signal responses regarding both the activated cortical areas and the dynamics of the signal time course. In contrast, signal time courses during block paradigms depend on the stimulus applied and are a complex and nonlinear function of the single-event responses. Additionally, the initial dip during the first 2 seconds after stimulus onset is consistently observed. However, the small amplitude change (-0.1% to -0.3%) requires signal averaging to establish statistical significance of the effect. Furthermore, different patterns of activation were observed within the primary visual cortex. In an anterior part of the primary visual cortex, activation was only observed at the onset and at the cessation of stimulation involving luminance changes.

  9. The experience of chronic illness in women: a comparison between women with endometriosis and women with chronic migraine headaches.

    PubMed

    Barnack, Jessica L; Chrisler, Joan C

    2007-01-01

    The diagnosis of a chronic illness is a life changing event that affects the biological, psychological, and sociological aspects of a person's life. The purpose of the present study was to compare the experiences of pain, physical and psychological well-being, stress, patient satisfaction, social support, and attitudes toward menstruation of women who suffer from endometriosis and women who suffer from chronic migraine headaches. It was hypothesized that women with endometriosis would have more negative scores than women who have migraines on all measures because endometriosis is not understood by society to be a valid source of pain. Participants were 41 women with endometriosis and 32 women with migraines who were recruited from support groups and online listservs. Women with endometriosis reported significantly more pain, stress, and negative attitudes toward menstruation than did women with migraines. Implications for the differential treatment of women with chronic illnesses related to the menstrual cycle are discussed.

  10. Polarizabilities of Ba and Ba{sub 2}: Comparison of molecular beam experiments with relativistic quantum chemistry

    SciTech Connect

    Schaefer, Sascha; Mehring, Max; Schaefer, Rolf; Schwerdtfeger, Peter

    2007-11-15

    The dielectric response to an inhomogeneous electric field has been investigated for Ba and Ba{sub 2} within a molecular beam experiment. The ratio of the polarizabilities per atom of Ba{sub 2} and Ba is determined to be 1.30{+-}0.13. The experimental result is compared to a high level ab initio quantum chemical coupled cluster calculation with an energy-consistent scalar relativistic small-core pseudopotential for Ba. For the barium atom a polarizability of 40.82 A{sup 3} is obtained and the isotropic value of the polarizability calculated for Ba{sub 2} is 97.88 A{sup 3}, which is in good agreement with the experimental results, demonstrating that a quantitative understanding of the interaction between two closed-shell heavy element metal atoms has been achieved.

  11. Comparison of wind tunnel and field experiments to measure potential deposition of fenpropimorph following volatilisation from treated crops.

    PubMed

    Hassink, Jan; Platz, Klaus; Stadler, Reinhold; Zangmeister, Werner; Fent, Gunnar; Möndel, Martin; Kubiak, Roland

    2007-02-01

    The potential for short-range transport via air, i.e. volatilisation from the area of application and subsequent deposition on adjacent non-target areas, was investigated for the fungicide fenpropimorph in a wind tunnel system and under outdoor conditions in a higher-tier field study. Fenpropimorph 750 g L(-1) EC was applied post-emergence to cereal along with a reference standard lindane EC. Stainless steel containers of water were placed at different distances downwind of the application area to trap volatile residues during a study period of 24 h following application. Meteorological conditions in the wind tunnel as well as on the field were constantly monitored during the study period. The wind tunnel system was a partly standardised system on a semi-field scale, i.e. wind direction and wind speed (2 m s(-1)) were constant, but temperature and humidity varied according to the conditions outside. In the field experiment, the average wind speed over the 24 h study period was 3 m s(-1) and no rainfall occurred. Three different measuring lines were installed on the non-target area beside the treated field to cover potential variations in the wind direction. However, no significant differences were observed since the wind direction was generally constant. Fenpropimorph was detected in minor amounts of 0.01-0.05% of the applied material in the wind tunnel experiment. Even at a distance of 1 m beside the treated field, no significant deposition occurred (0.04% of applied material after 24 h). In the field, less than 0.1% of the applied fenpropimorph was detected at 0 m directly beside the treated field. At 5 m distance the deposition values were below 0.04%, and at 20 m distance about 0.01%. In general, the amounts of deposited fenpropimorph detected in the partly standardised wind tunnel system and the higher-tier field study were in good agreement.

  12. TRAC PF1/MOD1 calculations and data comparisons for mist feed and bleed and steam generator tube rupture experiments

    SciTech Connect

    Siebe, D.A.; Boyack, B.E.; Steiner, J.L.

    1988-01-01

    Los Alamos National Laboratory is a participant in the Integral System Test (IST) program initiated in June 1983 for the purpose of providing integral system test data on specific issues/phenomena relevant to post-small-break loss-of-coolant accidents, loss of feedwater and other transients in Babcock and Wilcox (BandW) plant designs. The Multi-Loop Integral System Test (MIST) facility is the largest single component in the IST program. MIST is a 2 /times/ 4 (two hot legs and steam generators (SGs), four cold legs and reactor coolant pumps) representation of lowered-loop reactor system of the BandW design. It is a full-height, full-pressure facility with 1/817 power and volume scaling. Two other integral experimental facilities are included in the IST program: test loops at the University of Maryland, College Park, and at SRI International (SRI-2). The objective of the IST tests is to generate high-quality experimental data to be used for assessing thermal-hydraulic safety computer codes. Efforts are under way at Los Alamos to assess TRAC-PF1/MOD1 against data from each of the IST facilities. Calculations and data comparisons for TRAC-PF1/MOD1 assessment are presented for two transients run in the MIST facility. These are MIST Test 330302, a feed and bleed test with delayed high-pressure injection; and Test 3404AA, an SG tube-rupture test with the affected SG isolated. Only MIST assessment results are presented in this paper. The TRAC-PF1/MOD1 calculations completed to date for MIST tests are in reasonable agreement with the data from these tests. Reasonable agreement is defined as meaning that major trends are predicted correctly, although TRAC values are frequently outside the range of data uncertainty. We believe that correct conclusions will be reached if the code is used in similar applications despite minor code/model deficiencies. 7 refs., 5 figs., 2 tabs.

  13. Mean-field calculations of chain packing and conformational statistics in lipid bilayers: comparison with experiments and molecular dynamics studies.

    PubMed Central

    Fattal, D R; Ben-Shaul, A

    1994-01-01

    A molecular, mean-field theory of chain packing statistics in aggregates of amphiphilic molecules is applied to calculate the conformational properties of the lipid chains comprising the hydrophobic cores of dipalmitoyl-phosphatidylcholine (DPPC), dioleoyl-phosphatidylcholine (DOPC), and palmitoyl-oleoyl-phosphatidylcholine (POPC) bilayers in their fluid state. The central quantity in this theory, the probability distribution of chain conformations, is evaluated by minimizing the free energy of the bilayer assuming only that the segment density within the hydrophobic region is uniform (liquidlike). Using this distribution we calculate chain conformational properties such as bond orientational order parameters and spatial distributions of the various chain segments. The lipid chains, both the saturated palmitoyl (-(CH2)14-CH3) and the unsaturated oleoyl (-(CH2)7-CH = CH-(CH2)7-CH3) chains are modeled using rotational isomeric state schemes. All possible chain conformations are enumerated and their statistical weights are determined by the self-consistency equations expressing the condition of uniform density. The hydrophobic core of the DPPC bilayer is treated as composed of single (palmitoyl) chain amphiphiles, i.e., the interactions between chains originating from the same lipid headgroup are assumed to be the same as those between chains belonging to different molecules. Similarly, the DOPC system is treated as a bilayer of oleoyl chains. The POPC bilayer is modeled as an equimolar mixture of palmitoyl and oleoyl chains. Bond orientational order parameter profiles, and segment spatial distributions are calculated for the three systems above, for several values of the bilayer thickness (or, equivalently, average area/headgroup) chosen, where possible, so as to allow for comparisons with available experimental data and/or molecular dynamics simulations. In most cases the agreement between the mean-field calculations, which are relatively easy to perform, and the

  14. [Celiac disease and its diagnostic evolution. Comparisons and experiences in a hospital pediatric department (1975-1992). I].

    PubMed

    Della Morte, M A; Sala, M R; Morelli, P; Meschi, V; Silva, A; Valli, F

    1992-01-01

    The coeliac disease (CD) or gluten-sensitive enteropathy (GSE) is a permanent intolerance to wheat gliadin and to correlated proteins inducing malabsorption and typical damages of the jejunal mucosa (total or subtotal villous atrophy = SVA) in genetically-predisposed individuals ("DQW2"). A large amount of research has been devoted to CD pathogenesis: the most recent studies, thanks to sophisticated and experimental methods, support the pathogenetic immunological theory and the one of direct cytotoxicity. The correct diagnostic procedure for CD, established in 1970 by the European Society for Pediatric Gastroenterology and Nutrition (ESPGAN), suggested three small bowel mucosal biopsies. In the last years, because of the difficulties of such a practice, the necessity of non-invasive diagnostic approaches has developed; such approaches have been verified in absorption tests (one-hour blood xylose, intestinal permeability methods) and in immunogenetic tests (antibodies antigliadin, anti-reticulin, anti-endomysium, anti 90 KD glycoprotein, anti-human jejunum, HLA I/II antigens). The specific MHC antigens establish CD's incidence in several population and in particular situations, as in first-degree relatives and in diseases associated with CD (dermatitis herpetiformis (DH), insulin dependent diabetes mellitus (IDDM) and other auto-immune syndromes). The specific serum antibodies singly used as first level screening if estimated in combination with absorption tests, reach the highest levels of specificity and sensibility in CD diagnosis. It's anyway fundamental the comparison with at least a typical CD histological feature, caused by a challenge with a sufficient gluten to be carried in dubious cases and in non high auxological risk age (ESPGAN 1989). Adolescence is a period of frequent non compliance with a gluten-free diet and of particular psychological and physical problems: the apparent "gluten insensitivity", typical of teen-agers and adults, recalls the

  15. Comparison of Aromatic Hydrocarbon Measurements made by PTR-MS, DOAS and GC-FID during the MCMA 2003 Field Experiment

    SciTech Connect

    Jobson, Bertram T.; Volkamer, Rainer M.; Velasco, E.; Allwine, Gene; Westberg, Halvor H.; Lamb, Brian K.; Alexander, M. L.; Berkowitz, Carl M.; Molina, Luisa T.

    2010-02-15

    A comparison of aromatic hydrocarbon measurements is reported for the CENICA upersite in the district of Iztapalapa during the Mexico City Metropolitan Area field experiment in April 2003 (MCMA 2003). Data from three different measurement methods were compared: a Proton Transfer Reaction Mass Spectrometer (PTR-MS), long path measurements using a UV Differential Optical Absorption Spectrometer (DOAS), and Gas Chromatography-Flame Ionization analysis (GC-FID) of canister samples. The principle focus was on the comparison between PTR-MS and DOAS data. Lab tests established that the PTR-MS and DOAS calibrations were consistent for a suite of aromatic compounds including benzene, toluene, p-xylene, ethylbenzene, 1,2,4-trimethylbenzene, phenol and styrene. The point sampling measurements by the PTR-MS and GC-FID showed good correlations (r=0.6), and were in reasonable agreement for toluene, C₂-alkylbenzenes and C3-alkylbenzenes. The PTR-MS benzene data were consistently high, indicating interference from ethylbenzene fragmentation for the 145 Td drift field intensity used in the experiment. Correlations between the open-path data measured at 16-m height over a 860-m path length (retroreflector in 430m distance), and the point measurements collected at 37-m sampling height were best for benzene (r=0.61), and reasonably good for toluene, C2-alkylbenzenes, naphthalene, styrene, cresols and phenol (r>0.5). There was good agreement between DOAS and PTR-MS measurements of benzene after correction for the PTR-MS ethylbenzene interference. Mixing ratios easured by DOAS were on average a factor of 1.7 times greater than the PTR-MS data for toluene, C2-alkylbenzenes, naphthalene and styrene. The level of agreement for the toluene data displayed a modest dependence on wind direction, establishing that spatial gradients - horizontal, vertical, or both – in toluene mixing ratios were significant, and up to a factor of 2 despite the fact that all measurements were conducted above

  16. Comparisons between Stratospheric Aerosol and Gas Experiment II and microwave limb sounder ozone measurements and aliasing of SAGE II ozone trends in the lower stratosphere

    NASA Astrophysics Data System (ADS)

    Cunnold, D. M.; Wang, H.; Chu, W. P.; Froidevaux, L.

    1996-04-01

    SAGE II ozone measurements are compared with coincident microwave limb sounder (MLS) measurements over the period September 1991 to December 1993. Between 1.5 and 10 mbar the MLS ozone values are approximately 5% larger than the Stratospheric Aerosol and Gas Experiment (SAGE) II values. These differences are remarkably systematic in space and time. At 1 mbar the mean differences are zero and the mean differences oscillate with level at lower pressures. A month of comparisons against Halogen Occultation Experiment ozone measurements suggests that the differences at pressures less than 1.5 mbar are a feature of the MLS measurements. There are also differences between SAGE II sunrise and sunset measurements at 1 mbar which may be associated with the diurnal tide. At pressures greater than 10 mbar the comparisons indicate that the SAGE II ozone retrievals are being biased by the large aerosol concentrations resulting from the Mount Pinatubo eruption. For a fixed aerosol extinction the SAGE II/MLS difference (ppm) is larger at higher altitudes. It also depends nonlinearly on the aerosol extinction at pressures greater than 20 mbar. These effects are probably caused by the interpolation of the SAGE II aerosol extinction to 0.6 μm and by the evolution of the aerosol size distribution. For UARS layer aerosol optical depths less than 2 × 10-3 at 1.02 μm, the aerosol effect on the SAGE II ozone retrievals is inferred to be 3 × 1010 cm-3/10-3 aerosol layer optical depth at pressures greater than 20 mbar. This is equivalent to approximately 3% of the aerosol extinction at 0.6 μm being interpreted as ozone. At low aerosol concentrations and between 10 and 31 mbar, MLS ozone values are found to be approximately 5% larger than SAGE II ozone values (in agreement with the higher-altitude differences). Atmospheric aerosol concentrations prior to the Mount Pinatubo eruption were large enough, particularly in the tropics after Ruiz in 1985, that long-term trends in SAGE II ozone

  17. Comparison of morphology of active cyclic steps created by turbidity currents on Squamish Delta, British Columbia, Canada with flume experiments

    NASA Astrophysics Data System (ADS)

    Yokokawa, Miwa; Yamamoto, Shinya; Higuchi, Hiroyuki; Hughes Clarke, John E.; Izumi, Norihiro

    2015-04-01

    Upper-flow-regime bedforms, such as cyclic steps and antidunes, have been reported to be formed by turbidity currents. Their formative conditions are, however, not fully understood because of the difficulty of field surveys in the deep sea. Field observations of turbidity currents and seabed topography on the Squamish delta in Howe Sound, British Columbia, Canada have been undertaken which found bedwaves actively migrating in the upstream direction in channels formed on the prodelta slope. Their topography and behavior suggest that they are cyclic steps formed by turbidity currents. Because Squamish delta is as shallow as around 150 m, and easy to access compared with general submarine canyons, it is thought to be one of the best places for studying characteristics of cyclic steps formed by turbidity currents through field observations. In this study, we have analyzed configurations of cyclic steps with the use of data obtained in the field observation of 2011, and compare them with the data from the flume experiments. On the prodelta slope, three major active channels are clearly developed. In addition to the sonar survey, a 600 kHz ADCP was installed in 150m of water just seaward of the termination of the North Channel. In addition, 1200kHz ADCP and 500kHz M3s are suspended from the research vessel in 60 m of water and 300 m distance from the delta edge. We selected images showing large daily differences. The steps move vigorously at the upper 600m parts of the prodelta slope, so that we measured the steps in this area. From the profiles perpendicular to the bedwave crest lines through the center of channels, wavelength and wave height for each step, mean slope were measured on the software for quantitative image analyses manually. Wave steepness for each step was calculated using the wavelength and wave height measured as above. The mean slope ranges from 6.8° ~ 2.7° (more proximal, steeper), mean wavelength and wave heights of steps range from 24.5 to 87.6m

  18. Comparison of radiation dose and the effect of operator experience in femoral and radial arterial access for coronary procedures.

    PubMed

    Neill, Johanne; Douglas, Hannah; Richardson, Geoffrey; Chew, Eng-Wooi; Walsh, Simon; Hanratty, Colm; Herity, Niall

    2010-10-01

    Radial access coronary procedures are associated with fewer access site complications compared to femoral access. There is controversy regarding greater radiation exposure to patient and operator using radial access. We aimed to compare radiation dose during coronary procedures for the 2 access routes and assess the effect of operator experience with radial access on radiation dose. Fluoroscopy time (FT) and dose-area product (DAP) were recorded for all radial access and femoral access procedures during default femoral access, transition phase (femoral access and early radial access), and default radial access. Femoral access cases (n = 848, 412 diagnostic, 436 percutaneous coronary interventions [PCIs]) and radial access cases (n = 965, 459 diagnostic, 506 PCIs) were assessed. For diagnostics, median FT for radial access was longer than for femoral access (4.43 minutes, interquartile range [IQR] 2.55 to 8.18, vs 2.34 minutes, IQR 1.49 to 4.18, p <0.001) and associated with larger DAP (radial access 1,837 μGy·m(2), IQR 1,172 to 2,783, vs femoral access 1,657 μGy·m(2), IQR 1,064 to 2,376, p <0.001). For PCI, FT was longer for radial access (median 12.02 minutes, IQR 7.57 to 17.54, vs femoral access 9.36 minutes, IQR 6.13 to 14.27, p <0.001)-this did not translate into an increased DAP (femoral access median 3,392 μGy·m(2), IQR 2,139 to 5,193, vs radial access 3,682 μGy·m(2), IQR 2,388 to 5,314, p = NS). For diagnostic radial access, FT decreased from the transition phase (n = 134) to the default radial access phase (n = 323, 5.12 minutes, IQR 3.07 to 9.40, vs 4.21 minutes, IQR 2.49 to 7.52, p = 0.03). This was not observed for PCI. In conclusion, transition from femoral access to radial access for diagnostics and PCI increased FT. DAP increased for diagnostic radial access but not PCI compared with femoral access. FTs for radial access diagnostic cases decreased with experience.

  19. Pain Experience and Behavior Management in Pediatric Dentistry: A Comparison between Traditional Local Anesthesia and the Wand Computerized Delivery System

    PubMed Central

    D'Antò, Vincenzo; Fauxpoint, Gabriel; De Rosa, Sara; Vallogini, Giulia

    2017-01-01

    Aim. To evaluate the pain experience and behavior during dental injection, using the Wand computerized delivery system versus conventional local anesthesia in children and adolescents. Methods. An observational crossover split mouth study was performed on 67 patients (aged 7 to 15 years), requiring local anesthesia for dental treatments in both sides of the dental arch. Patients received both types of injections in two separate appointments, one with the use of a Computer Delivery System (the Wand STA system) and one with the traditional syringe. The following data were recorded: pain rating; changes in heart rate; level of collaboration; patient satisfaction. The data were analyzed using ANOVA for quantitative outcomes and nonparametric analysis (Kruskal–Wallis) for qualitative parameters. Results. The use of the Wand system determined significantly lower pain ratings and lower increase of heart rate than the traditional syringe. During injection, the number of patients showing a relaxed behavior was higher with the Wand than with the traditional local anesthesia. The patient level of satisfaction was higher with the Wand compared to the conventional local anesthesia. Conclusions. The Wand system may provide a less painful injection when compared to the conventional local anesthesia and it seemed to be better tolerated with respect to a traditional syringe. PMID:28293129

  20. Reduced model simulations of the scrape-off-layer heat-flux width and comparison with experiment

    DOE PAGES

    Myra, J. R.; Russell, D. A.; D’Ippolito, D. A.; ...

    2011-01-01

    Reduced model simulations of turbulence in the edge and scrape-off-layer (SOL) region of a spherical torus or tokamak plasma are employed to address the physics of the scrape-off-layer heat flux width. The simulation model is an electrostatic two-dimensional fluid turbulence model, applied in the plane perpendicular to the magnetic field at the outboard midplane of the torus. The model contains curvature-driven-interchange modes, sheath losses, and both perpendicular turbulent diffusive and convective (blob) transport. These transport processes compete with classical parallel transport to set the SOL width. Midplane SOL profiles of density, temperature and parallel heat flux are obtained from themore » simulation and compared with experimental results from the National Spherical Torus Experiment (NSTX) to study the scaling of the heat flux width with power and plasma current. It is concluded that midplane turbulence is the main contributor to the SOL heat flux width for the low power H-mode discharges studied, while additional physics is required to explain the plasma current scaling of the SOL heat flux width observed experimentally in higher power discharges. Intermittent separatrix spanning convective cells are found to be the main mechanism that sets the near-SOL width in the simulations. The roles of sheared flows and blob trapping vs. emission are discussed.« less

  1. Approaches of comparison for clear-sky radiative fluxes from general circulation models with Earth Radiation Budget Experiment data

    NASA Technical Reports Server (NTRS)

    Zhang, M. H.; Cess, R. D.; Kwon, T. Y.; Chen, M. H.

    1994-01-01

    In order to compare the clear-sky greenhouse effect and cloud-radiative forcing from general circulation models with Earth Radiation Budget Experiments (ERBE) data, it is necessary to calculate the general circulation model (GCM) clear-sky radiative fluxes in a way consistent with ERBE. This study discusses problems associated with the available methods for clear-sky radiative flux computations in GCMs and proposes a new approach, which uses a statistical relationship between the grid cloud cover and the availability of ERBE clear-sky measurement, established from ERBE pixel data, to sample the model radiative fluxes. Calculations with version 2 of the National Center for Atmospheric Research (NCAR) Community Climate Model using observed sea surface temperature (SST) show good agreement of clear-sky sampling from the proposed method with ERBE sampling. It is also shown that large improvements are achieved in the spatial variability of the model clear-sky radiative fluxes over ocean, with reference to ERBE, by using the new clear-sky sampling method.

  2. Comparison of horizontal dust fluxes simulated with two dust emission schemes based on field experiments in Xinjiang, China

    NASA Astrophysics Data System (ADS)

    Yang, Xinghua; Yang, Fan; Liu, Xinchun; Huo, Wen; He, Qing; Mamtimin, Ali; Zhang, Qingyu

    2016-10-01

    Horizontal dust fluxes were simulated with two different dust emission schemes developed by Marticorena and Shao (hereinafter referred to as the M scheme, S scheme, and S scheme corrections), based on field experiments over a bare desert surface and a vegetated desert surface from May 19 to June 18, 2010 in Xinjiang, China. The M scheme produced a much higher dust emission than the S schemes over different surface conditions, with the emission being about 4 times larger than that produced by the S schemes over the bare desert, and 3 to 200 times larger over the vegetated surface. Compared to observations, the missing report rate of wind erosion events was about 30 % for the S schemes and about 10 % for the M scheme over the bare desert surface, while all schemes had a false alarm rate of wind erosion events over the vegetated desert surface. The total dust emission from the bare desert surface during the study period was 674.4, 551.5, 595.2, and 2995.8 kg/m for observation, the S scheme, S scheme correction 2, and M scheme, respectively. Total dust emission from the vegetated desert surface was 1.6, 0, 55.5, 0.9, and 227.7 kg/m for observation, the S scheme, S scheme correction 1, S scheme correction 2, and M scheme, respectively.

  3. Reduced model simulations of the scrape-off-layer heat-flux width and comparison with experiment

    SciTech Connect

    Myra, J. R.; Russell, D. A.; D’Ippolito, D. A.; Ahn, J.-W.; Maingi, R.; Maqueda, R. J.; Lundberg, D. P.; Stotler, D. P.; Zweben, S. J.; Boedo, J.; Umansky, M.

    2011-01-01

    Reduced model simulations of turbulence in the edge and scrape-off-layer (SOL) region of a spherical torus or tokamak plasma are employed to address the physics of the scrape-off-layer heat flux width. The simulation model is an electrostatic two-dimensional fluid turbulence model, applied in the plane perpendicular to the magnetic field at the outboard midplane of the torus. The model contains curvature-driven-interchange modes, sheath losses, and both perpendicular turbulent diffusive and convective (blob) transport. These transport processes compete with classical parallel transport to set the SOL width. Midplane SOL profiles of density, temperature and parallel heat flux are obtained from the simulation and compared with experimental results from the National Spherical Torus Experiment (NSTX) to study the scaling of the heat flux width with power and plasma current. It is concluded that midplane turbulence is the main contributor to the SOL heat flux width for the low power H-mode discharges studied, while additional physics is required to explain the plasma current scaling of the SOL heat flux width observed experimentally in higher power discharges. Intermittent separatrix spanning convective cells are found to be the main mechanism that sets the near-SOL width in the simulations. The roles of sheared flows and blob trapping vs. emission are discussed.

  4. Phase behaviour of PMMA-b-PHEMA with solvents methanol and THF: modelling and comparison to the experiment.

    PubMed

    Padmanabhan, P; Chavis, M; Ober, C K; Escobedo, F A

    2014-09-07

    Self-consistent field theory is used to model the self-assembly of a symmetric PMMA-block-PHEMA in the presence of two solvents, methanol and tetrahydrofuran (THF). The model predictions are compared to our experimental results of solvent-vapour annealing of thin polymer films, where the sequence of cylinder to gyroid (or micelles) to lamellar phases was found upon increasing the methanol-THF ratio and for particular extents of film swelling. The Hansen solubility parameters are used to estimate the Flory-Huggins interaction parameters (χ) needed in the theoretical model. However, because enacting the experimental range of high (χ)N values is computationally prohibitive, the use of moderate (χ)N values is compensated by employing larger values of the solvent-to-polymer size ratio (α). This approach is validated by showing that the predicted phase diagrams exhibit qualitatively similar trends whether (χ)N or α is increased. Using such an approach, the theory predicts a cylinder to gyroid to lamellar transition on increasing the THF-methanol ratio, a trend consistent with that observed in the experiments.

  5. Approaches of comparison for clear-sky radiative fluxes from general circulation models with earth radiation budget experiment data

    SciTech Connect

    Zhang, M.H.; Cess, R.D.; Kwon, T.Y.; Chen, M.H.

    1994-03-20

    In order to compare the clear-sky greenhouse effect and cloud-radiative forcing from general circulation models with Earth Radiation Budget Experiments (ERBE) data, it is necessary to calculate the general circulation model (GCM) clear-sky radiative fluxes in a way consistent with ERBE. This study discusses problems associated with the available methods for clear-sky radiative flux computations in GCMs and proposes a new approach, which uses a statistical relationship between the grid cloud cover and the availability of ERBE clear-sky measurement, established from ERBE pixel data, to sample the model radiative fluxes. Calculations with version 2 of the NCAR Community Climate Model using observed SST show good agreement of clear-sky sampling from the proposed method with ERBE sampling. It is also shown that large improvements are achieved in the spatial variability of the model clear-sky radiative fluxes over ocean, with reference to ERBE, by using the new clear-sky sampling method. 11 refs., 10 figs.

  6. A comparison of vertical velocity in cirrus obtained from aircraft and lidar divergence measurements during FIRE. [First ISCCP Regional Experiment

    NASA Technical Reports Server (NTRS)

    Gultepe, Ismail; Heymsfield, A. J.; Lenschow, D. H.

    1990-01-01

    Techniques are presented to obtain vertical velocity in cirrus clouds from in situ aircraft lateral wind measurements and from ground-based remote Doppler lidar measurements. The approach used is to calculate w from the integral of the divergence of the horizontal velocity around a closed path. Divergence measurements from both aircraft and Doppler lidar are discussed. The principal errors in the calculation of w from aircraft lateral wind measurements are bias in the lateral wind, ground speed errors, and error due to vertical shear of the horizontal wind. For Doppler lidar measurements the principal errors are in the estimate of mean terminal velocity and the zeroth order coefficients of the Fourier series that is fitted to the data. The technique is applied to a cirrus cloud investigated during the FIRE (First International Satellite Cloud Climatology Regional Experiment) Cirrus Intensive Field Observation Program. The results indicate that the error in w is about + or - 14 cm/s from the aircraft technique; this can be reduced to about + or - 2 to 3 cm/s with technical improvements in both ground speed and lateral velocity measurements. The error in w from Doppler lidar measurements, which is about + or - 8 cm/s, can be reduced to about + or - 5 cm/s by improvements in the Doppler velocity measurements with technology that is currently available.

  7. Spectrometric analyses in comparison to the physiological condition of heavy metal stressed floodplain vegetation in a standardised experiment

    NASA Astrophysics Data System (ADS)

    Götze, Christian; Jung, András; Merbach, Ines; Wennrich, Rainer; Gläßer, Cornelia

    2010-06-01

    Floodplain ecosystems are affected by flood dynamics, nutrient supply as well as anthropogenic activities. Heavy metal pollution poses a serious environmental challenge. Pollution transfer from the soil to vegetation is still present at the central location of Elbe River, Germany. The goal of this study was to assess and separate the current heavy metal contamination of the floodplain ecosystem, using spectrometric field and laboratory measurements. A standardized pot experiment with floodplain vegetation in differently contaminated soils provided the basis for the measurements. The dominant plant types of the floodplains are: Urtica dioica, Phalaris arundinacea and Alopecurus pratensis, these were also chemically analysed. Various vegetation indices and methods were used to estimate the red edge position, to normalise the spectral curve of the vegetation and to investigate the potential of different methods for separating plant stress in floodplain vegetation. The main task was to compare spectral bands during phenological phases to find a method to detect heavy metal stress in plants. A multi-level algorithm for the curve parameterisation was developed. Chemo-analytical and ecophysiological parameters of plants were considered in the results and correlated with spectral data. The results of this study show the influence of heavy metals on the spectral characteristics of the focal plants. The developed method (depth CR1730) showed significant relationship between the plants and the contamination.

  8. Space and time distribution of HF excited Langmuir turbulence in the ionosphere: Comparison of theory and experiment

    SciTech Connect

    Dubois, D.F.; Hanssen, A.; Rose, H.A.; Russell, D.

    1993-10-01

    The predictions of strong Langmuir turbulence (SLT) theory are compared with radar observations of HF induced turbulence at Arecibo and Tromso. The altitude distribution of turbulence observed in the cold start experiments of Fejer et al. imply that the ionospheric electron density profile is modified by the induced turbulence. The preconditioned observations at Arecibo and the Tromso observations also appear to require a {open_quotes}disturbed{close_quotes} profile with several percent density fluctuations. With such density modifications postulated the authors conclude the SLT theory is in, at least, qualitative agreement with a large body of observations. Specifically SLT theory predicts, as part of a unified theory, and in distinction to the weak turbulence approximation, at least four unique physical signatures which can be compared to observations: (1) A caviton continuum plus free mode peak in the plasma line power spectrum near reflection altitude for Arecibo conditions. (2) A truncated decay-cascade spectrum at lower altitudes (or densities). (3) A continuous spectrum underlying the decay-cascade spectrum. (4) A zero frequency feature in the ion line power spectrum directly related to caviton dynamics. The authors find that there is sufficient ponderomotive pressure due to the Airy-layered, induced Langmuir turbulence, to modify the electron density profile in a manner consistent with the time behavior of unpreconditioned Arecibo observations. 59 refs., 14 figs.

  9. Implant-assisted magnetic drug targeting in permeable microvessels: Comparison of two-fluid statistical transport model with experiment

    NASA Astrophysics Data System (ADS)

    ChiBin, Zhang; XiaoHui, Lin; ZhaoMin, Wang; ChangBao, Wang

    2017-03-01

    In experiments and theoretical analyses, this study examines the capture efficiency (CE) of magnetic drug carrier particles (MDCPs) for implant-assisted magnetic drug targeting (IA-MDT) in microvessels. It also proposes a three-dimensional statistical transport model of MDCPs for IA-MDT in permeable microvessels, which describes blood flow by the two-fluid (Casson and Newtonian) model. The model accounts for the permeable effect of the microvessel wall and the coupling effect between the blood flow and tissue fluid flow. The MDCPs move randomly through the microvessel, and their transport state is described by the Boltzmann equation. The regulated changes and factors affecting the CE of the MDCPs in the assisted magnetic targeting were obtained by solving the theoretical model and by experimental testing. The CE was negatively correlated with the blood flow velocity, and positively correlated with the external magnetic field intensity and microvessel permeability. The predicted CEs of the MDCPs were consistent with the experimental results. Additionally, under the same external magnetic field, the predicted CE was 5-8% higher in the IA-MDT model than in the model ignoring the permeability effect of the microvessel wall.

  10. Two fluid effects on three-dimensional reconnection in the Swarthmore Spheromak Experiment with comparisons to space data

    SciTech Connect

    Brown, M.R.; Cothran, C.D.; Fung, J.

    2006-05-15

    Several new experimental results are reported from spheromak merging studies at the Swarthmore Spheromak Experiment [M. R. Brown, Phys. Plasmas 6, 1717 (1999)] with relevance to three-dimensional (3D) reconnection in laboratory and space plasmas. First, recent velocity measurements of impurity ions using ion Doppler spectroscopy are reported. Bidirectional outflow at nearly the Alfven speed is clearly observed. Second, experimental measurements of the out-of-plane magnetic field in a reconnection volume showing a quadrupolar structure at the ion inertial scale are discussed. Third, a measurement of in-plane Hall electric field and nonideal terms of the generalized Ohm's law in a reconnection volume of a weakly collisional laboratory plasma is presented. Time resolved vector magnetic field measurements on a 3D lattice [B(r,t)] enables evaluation of the various terms. Results show that the Hall electric field dominates everywhere (JxB/ne) and also exhibits a quadrupolar structure at the ion inertial scale; resistive and electron inertia terms are small. Each of these is related to and compared with similar measurements in a solar or space context.

  11. Insight into acid-base nucleation experiments by comparison of the chemical composition of positive, negative, and neutral clusters.

    PubMed

    Bianchi, Federico; Praplan, Arnaud P; Sarnela, Nina; Dommen, Josef; Kürten, Andreas; Ortega, Ismael K; Schobesberger, Siegfried; Junninen, Heikki; Simon, Mario; Tröstl, Jasmin; Jokinen, Tuija; Sipilä, Mikko; Adamov, Alexey; Amorim, Antonio; Almeida, Joao; Breitenlechner, Martin; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Kangasluoma, Juha; Keskinen, Helmi; Kim, Jaeseok; Kirkby, Jasper; Laaksonen, Ari; Lawler, Michael J; Lehtipalo, Katrianne; Leiminger, Markus; Makhmutov, Vladimir; Mathot, Serge; Onnela, Antti; Petäjä, Tuukka; Riccobono, Francesco; Rissanen, Matti P; Rondo, Linda; Tomé, António; Virtanen, Annele; Viisanen, Yrjö; Williamson, Christina; Wimmer, Daniela; Winkler, Paul M; Ye, Penglin; Curtius, Joachim; Kulmala, Markku; Worsnop, Douglas R; Donahue, Neil M; Baltensperger, Urs

    2014-12-02

    We investigated the nucleation of sulfuric acid together with two bases (ammonia and dimethylamine), at the CLOUD chamber at CERN. The chemical composition of positive, negative, and neutral clusters was studied using three Atmospheric Pressure interface-Time Of Flight (APi-TOF) mass spectrometers: two were operated in positive and negative mode to detect the chamber ions, while the third was equipped with a nitrate ion chemical ionization source allowing detection of neutral clusters. Taking into account the possible fragmentation that can happen during the charging of the ions or within the first stage of the mass spectrometer, the cluster formation proceeded via essentially one-to-one acid-base addition for all of the clusters, independent of the type of the base. For the positive clusters, the charge is carried by one excess protonated base, while for the negative clusters it is carried by a deprotonated acid; the same is true for the neutral clusters after these have been ionized. During the experiments involving sulfuric acid and dimethylamine, it was possible to study the appearance time for all the clusters (positive, negative, and neutral). It appeared that, after the formation of the clusters containing three molecules of sulfuric acid, the clusters grow at a similar speed, independent of their charge. The growth rate is then probably limited by the arrival rate of sulfuric acid or cluster-cluster collision.

  12. The initial magnetic susceptibility of polydisperse ferrofluids: A comparison between experiment and theory over a wide range of concentration

    NASA Astrophysics Data System (ADS)

    Solovyova, Anna Y.; Goldina, Olga A.; Ivanov, Alexey O.; Lebedev, Aleksandr V.; Elfimova, Ekaterina A.

    2016-08-01

    Temperature dependencies of the static initial magnetic susceptibility for ferrofluids at various concentrations are studied using experiment and statistical-mechanical theories. Magnetic susceptibility measurements are carried out for twelve samples of magnetite-based fluids stabilized with oleic acid over a wide range of temperatures (210 K ≲T ≲ 390 K); all samples have the same granulometric composition but different volume ferroparticle concentrations (0.2 ≲ φ ≲ 0.5). Experimental results are analyzed using three theories: the second-order modified mean-field theory (MMF2) [A. O. Ivanov and O. B. Kuznetsova, Phys. Rev. E 64, 41405 (2001)]; its correction for polydisperse ferrofluids arising from Mayer-type cluster expansion and taking into account the first terms of the polydisperse second virial coefficient [A. O. Ivanov and E. A. Elfimova, J. Magn. Magn. Mater 374, 327 (2015)]; and a new theory based on MMF2 combined with the first terms of the polydisperse second and third virial contributions to susceptibility. It turns out that the applicability of each theory depends on the experimental sample density. If twelve ferrofluid samples are split into three groups of strong, moderate, and low concentrated fluids, the temperature dependences of the initial magnetic susceptibility in each group are very precisely described by one of the three theories mentioned above. The determination of a universal formula predicting a ferrofluid susceptibility over a broad range of concentrations and temperatures remains as a challenge.

  13. A comparison of the postdeployment hospitalization experience of U.S. military personnel following service in the 1991 Gulf War, Southwest Asia after the Gulf War, and Bosnia.

    PubMed

    Smith, Besa; Smith, Tyler C; Ryan, Margaret A K; Gray, Gregory C

    2006-12-01

    Much attention has been given to the impact of deployment on the health of veterans from the 1991 Gulf War. Whereas increases in self-reported symptoms have been common, no specific exposures have been implicated. Some have suggested that stress from deployment is the chief cause for multisymptom conditions among Gulf War veterans, but comparisons with the health of other recent deployers have not been made. We sought to examine the impact of several large military deployments on hospitalization experience. Hospitalization records were examined for all active duty personnel deployed exclusively to the Gulf War, Southwest Asia after the Gulf War, or Bosnia. Cox's hazard modeling was used to assess time until first post-deployment hospitalization, separation from active duty, or December 31, 2000, whichever occurred first, while controlling for influential covariates and temporal changes. Personnel deployed to Southwest Asia after the 1991 Gulf War were at a slight increased risk for any-cause hospitalization and for 3 of the 14 major diagnostic categories when compared with veterans of the 1991 Gulf War. Personnel deployed to Bosnia were at a decreased risk for any-cause hospitalization and 12 of the 14 major diagnostic categories when compared with Gulf War veterans. These findings do not fully explain the complexity of postdeployment health experiences. Although the risk for hospitalization may be associated with regional deployment, it is unlikely that Gulf War veterans are at greater risk of hospitalization due to a specific exposure-related disease.

  14. Analysis of Radiation from Implosions of Stainless Steel Wire Arrays on Zebra and Comparison with Laser Plasma Experiments on Leopard at UNR*.

    NASA Astrophysics Data System (ADS)

    Safronova, A. S.; Kantsyrev, V. L.; Shrestha, I.; Shlyaptseva, V. V.; Weller, M. E.; Osborne, G. C.; Williamson, K. M.; Stafford, A.; Keim, S. F.; Faenov, A. Ya.; Esaulov, A. A.; Wiewior, P.; Legalloudec, N.; Paudel, Y.; Coverdale, C. A.; Chuvatin, A. S.

    2011-10-01

    The implosions of Stainless Steel (SS) Wire Arrays are extensively studied at SNL and also have applications in astrophysics. The analysis of radiation from low-number-wire SS Single and Nested Cylindrical, and Planar Wire Array experiments on the 1 MA Zebra is presented. The major focus is on x-ray imaging and spectra, total radiation yields, and fast, filtered x-ray detector data. The results of Leopard laser experiments with a flat 25 μm Fe target in the nanosecond (ns) and 350 femtosecond (fs) pulse regimes are discussed and compared with Z-pinch data. This comparison focuses mainly on L-shell Fe radiation and provides an excellent benchmark to the Z-pinch results. Good agreement with laser data is demonstrated in the ns regime, but a substantial difference is observed for the fs pulse. This work was supported by NNSA under DOE Coop. Agreements DE-FC52-06NA27588, 27586, and 27616. SNL is a multi-program laboratory managed and operated by Sandia Corp., a wholly owned subsidiary of Lockheed Martin Co., for the U.S. DOE under Contract DE-AC04-94AL85000.

  15. Effects of Na+ and Mg2+ on the structures of supercoiled DNAs: comparison of simulations with experiments.

    PubMed

    Gebe, J A; Delrow, J J; Heath, P J; Fujimoto, B S; Stewart, D W; Schurr, J M

    1996-09-20

    calculated. Agreement between simulations and experiments in regard to [symbol: see text] I(O) [symbol: see text] /[symbol: see text] I(k) [symbol: see text], D(zero) and the supercoiling free energy, delta Gsc (delta l), is remarkably good for the most extensively studied p30 delta samples. The simulated structures exhibit no sign of very tight interwinding with extensive lateral contacts, but instead exhibit most probable superhelix diameters of 85 to 90 A. When 4 mM Mg2+ was added to native supercoiled p30 delta in 0.1 M NaCl, Rg decreased, D(zero) increased, and the longest internal relaxation rate (1/tau 2(zero)) increased, all of which indicate a further overall contraction of the molecular envelope. The torsion constant exhibited a slight increase that is hardly statistically significant. In this case, agreement between the simulations and experiments was only semi-quantitative for most samples investigated, although the predicted contraction was exhibited by all five samples of p30 delta and one of pBR322 DNA. The simulated structures in 0.1 M NaCl plus 4 mM Mg2+ again showed no sign of extensive lateral contacts. A plausible explanation is proposed for the highly extended, tightly interwound structures seen in cryo-EM, and explicitly tested by Monte Carlo simulations of a 1000 bp circular DNA at +25 and -50 degrees C. Structures identical to those seen in cryo-EM are in fact the equilibrium structures in the simulations at -50 degrees C, and the estimated time for equilibration (2.3 x 10(-6) second) is much smaller than the estimated time for vitrification (1 x 10(-4) second).

  16. Investigation of capillary nanosecond discharges in air at moderate pressure: comparison of experiments and 2D numerical modelling

    NASA Astrophysics Data System (ADS)

    Klochko, Andrei V.; Starikovskaia, Svetlana M.; Xiong, Zhongmin; Kushner, Mark J.

    2014-09-01

    Nanosecond electrical discharges in the form of ionization waves are of interest for rapidly ionizing and exciting complex gas mixtures to initiate chemical reactions. Operating with a small discharge tube diameter can significantly increase the specific energy deposition and so enable optimization of the initiation process. Analysis of the uniformity of energy release in small diameter capillary tubes will aid in this optimization. In this paper, results for the experimentally derived characteristics of nanosecond capillary discharges in air at moderate pressure are presented and compared with results from a two-dimensional model. The quartz capillary tube, having inner and outer diameters of 1.5 and 3.4 mm, is about 80 mm long and filled with synthetic dry air at 27 mbar. The capillary tube with two electrodes at the ends is inserted into a break of the central wire of a long coaxial cable. A metal screen around the tube is connected to the cable ground shield. The discharge is driven by a 19 kV 35 ns voltage pulse applied to the powered electrode. The experimental measurements are conducted primarily by using a calibrated capacitive probe and back current shunts. The numerical modelling focuses on the fast ionization wave (FIW) and the plasma properties in the immediate afterglow after the conductive plasma channel has been established between the two electrodes. The FIW produces a highly focused region of electric field on the tube axis that sustains the ionization wave that eventually bridges the electrode gap. Results from the model predict FIW propagation speed and current rise time that agree with the experiment.

  17. Comparison of pharmacist and public views and experiences of community pharmacy medicines-related services in England

    PubMed Central

    Rodgers, Ruth M; Gammie, Shivaun M; Loo, Ruey Leng; Corlett, Sarah A; Krska, Janet

    2016-01-01

    Background Services provided by community pharmacists designed to support people using medicines are increasing. In England, two national services exist: Medicine Use Reviews (MUR) and New Medicines Service (NMS). Very few studies have been conducted seeking views of the public, rather than service users, on willingness to use these services or expectations of these services, or determined whether views align with pharmacist perceptions. Objective To compare the perceptions of pharmacists and the general public on medicines-related services, particularly MUR and NMS services. Methods Two parallel surveys were conducted in one area of England: one involved the general public and was administered using a street survey, and the other was a postal survey of community pharmacists. Similar questionnaires were used, seeking views of services, awareness, reasons for using services, and perceived benefits. Results Response rates were 47.2% (1,000/2,012 approached) for the public and 40.8% (341/836) for pharmacists. Few people had experienced a discussion in a private consultation room or were aware of the two formal services, although their willingness to use them was high. Pharmacists estimated time spent on service provision as 10 minutes for MUR and 12 minutes for NMS, which aligned with acceptability to both pharmacists and the public. Pharmacists underestimated the willingness of the public to wait for an informal discussion or to make appointments for formal services. Both pharmacists and the public had high expectations that services would be beneficial in terms of increasing knowledge and understanding, but public expectations and experiences of services helping to sort out problems fell well below pharmacists’ perceptions. People who had experienced a pharmacy service had different perceptions of pharmacists. Conclusion Views differed regarding why people use services and key aspects of service delivery. For services to improve, the pharmacy profession needs a

  18. Temperature and pressure retrievals from the Atmospheric Chemistry Experiment (ACE): a new technique and comparison with COSMIC

    NASA Astrophysics Data System (ADS)

    Olsen, Kevin; Strong, Kimberly; Toon, Geoff; Boone, Chris

    We present results of a new technique to retrieve temperature and pressure profiles from satellite remote sensing spectra collected by the Canadian Space Agency's (CSA) Atmospheric Chemistry Experiment (ACE), which recently celebrated its tenth year in orbit. ACE utilizes a high-resolution (0.02 cm (-1) ) Fourier Transform Spectrometer (FTS) operating between 750-4400 cm (-1) in limb-scanning mode using the sun as a light source (solar occultation). This technique benefits from high signal strength, high resolution, and self calibration. The CSA and NASA's Jet Propulsion Laboratory (JPL) developed a proposal to send a similar instrument to Mars: the Mars Atmospheric Trace Molecule Occultation Spectrometer (MATMOS, later canceled). To support this we have developed a new set of retrieval algorithms based on GGG used by the Total Carbon Column Observing Network (TCCON) and have applied these algorithms to ACE-FTS data. When performing temperature retrievals, the current approach of the ACE team is to fix the volume mixing ratio of CO_2 and carry out spectral fitting, varying temperature. While this method works very well and has been well validated, it relies on several assumptions, emph{a priori} knowledge, and data from models. Operating at another planet, these emph{a priori} are unknown and the models have not been developed to a suitable level. We demonstrate that by analyzing vibration-rotation bands of CO_2, we can retrieve vertical profiles of both temperature and pressure. Our retrieved temperature profiles are compared to those from ACE and the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC), and are used to retrieve volume mixing ratio vertical profiles for several gases, such as methane. The effects that variability in temperature and pressure have on retrieved VMR profiles is shown and retrieved VMR profiles are compared with those from ACE.

  19. A comparison of different transarterial embolization techniques for direct carotid cavernous fistulas: a single center experience in 32 patients

    PubMed Central

    Lu, Xiaojian; Hussain, Mohammed; Ni, Lanchun; Huang, Qinfeng; Zhou, Fei; Gu, Zhikai; Chen, Jian; Ding, Yuchuan; Xu, Feng

    2014-01-01

    Objective Transarterial treatment of direct carotid cavernous fistulas (DCCF) via embolic materials has been well documented. This study reports, validates, and compares with existing literature our experience treating DCCFs via endovascular approaches by using detachable balloons, coils, and covered stents. Methods Between June 2006 to October 2011, 32 patients (21 male, 11 female) with 32 DCCFs (30 traumatic, 2 spontaneous cavernous ICA aneurysms) were embolized endovascularly. Followup was performed for at least 6 months. Results Among the 32 DCCFs, 21 (65.6%) were embolized using detachable balloons, eight (25.0%) with coils, one (3.1%) with balloons and coils, and two (6.3%) with covered stents. Complete DCCF obliteration was achieved in 31 (96.9%) cases. One fistula failed to respond due to premature balloon detachment. Intracranial bruit in 31 (100%) chemosis and exophthalmos in 28 (100%) cases resolved after embolization. Visual acuity and oculomotor palsy improved in 18 (90%) and 18 (69.2%) cases, respectively. There was no evidence of DCCF recurrence. Thirteen DCCFs were followed up by MRI and five by DSA. In these cases, four (4/13, 30.8%) balloon-embolized DCCFs showed pseudoaneurysms. Three patients were asymptomatic; one had minor left oculomotor palsy. Conclusions Our results correlate and reinforce literature regarding endovascular treatment of DCCFs. Application of Transarterial embolization with detachable balloons, despite extensive use has been decreasing. Coil embolization is an effective and safe alternative for treatment, especially when balloon embolization fails. Covered stent placement may be used as another alternative for selected cases. PMID:25566340

  20. Impact of dilution on microbial community structure and functional potential: comparison of numerical simulations and batch culture experiments

    NASA Technical Reports Server (NTRS)

    Franklin, R. B.; Garland, J. L.; Bolster, C. H.; Mills, A. L.

    2001-01-01

    A series of microcosm experiments was performed using serial dilutions of a sewage microbial community to inoculate a set of batch cultures in sterile sewage. After inoculation, the dilution-defined communities were allowed to regrow for several days and a number of community attributes were measured in the regrown assemblages. Based upon a set of numerical simulations, community structure was expected to differ along the dilution gradient; the greatest differences in structure were anticipated between the undiluted-low-dilution communities and the communities regrown from the very dilute (more than 10(-4)) inocula. Furthermore, some differences were expected among the lower-dilution treatments (e.g., between undiluted and 10(-1)) depending upon the evenness of the original community. In general, each of the procedures used to examine the experimental community structures separated the communities into at least two, often three, distinct groups. The groupings were consistent with the simulated dilution of a mixture of organisms with a very uneven distribution. Significant differences in community structure were detected with genetic (amplified fragment length polymorphism and terminal restriction fragment length polymorphism), physiological (community level physiological profiling), and culture-based (colony morphology on R2A agar) measurements. Along with differences in community structure, differences in community size (acridine orange direct counting), composition (ratio of sewage medium counts to R2A counts, monitoring of each colony morphology across the treatments), and metabolic redundancy (i.e., generalist versus specialist) were also observed, suggesting that the differences in structure and diversity of communities maintained in the same environment can be manifested as differences in community organization and function.

  1. Correlated two-particle diffusion in dense colloidal suspensions at early times: Theory and comparison to experiment.

    PubMed

    Dell, Zachary E; Tsang, Boyce; Jiang, Lingxiang; Granick, Steve; Schweizer, Kenneth S

    2015-11-01

    The spatially resolved diffusive dynamic cross correlations of a pair of colloids in dense quasi-two-dimensional monolayers of identical particles are studied experimentally and theoretically at early times where motion is Fickian. In very dense systems where strong oscillatory equilibrium packing correlations are present, we find an exponential decay of the dynamic cross correlations on small and intermediate length scales. At large separations where structure becomes random, an apparent power law decay with an exponent of approximately -2.2 is observed. For a moderately dense suspension where local structural correlations are essentially absent, this same apparent power law decay is observed over all probed interparticle separations. A microscopic nonhydrodynamic theory is constructed for the dynamic cross correlations which is based on interparticle frictional effects and effective structural forces. Hydrodynamics enters only via setting the very short-time single-particle self-diffusion constant. No-adjustable-parameter quantitative predictions of the theory for the dynamic cross correlations are in good agreement with experiment over all length scales. The origin of the long-range apparent power law is the influence of the constraint of fixed interparticle separation on the amplitude of the mean square force exerted on the two tagged particles by the surrounding fluid. The theory is extended to study high-packing-fraction 3D hard sphere fluids. The same pattern of an oscillatory exponential form of the dynamic cross correlation function is predicted in the structural regime, but the long-range tail decays faster than in monolayers with an exponent of -3.

  2. Correlated two-particle diffusion in dense colloidal suspensions at early times: Theory and comparison to experiment

    NASA Astrophysics Data System (ADS)

    Dell, Zachary E.; Tsang, Boyce; Jiang, Lingxiang; Granick, Steve; Schweizer, Kenneth S.

    2015-11-01

    The spatially resolved diffusive dynamic cross correlations of a pair of colloids in dense quasi-two-dimensional monolayers of identical particles are studied experimentally and theoretically at early times where motion is Fickian. In very dense systems where strong oscillatory equilibrium packing correlations are present, we find an exponential decay of the dynamic cross correlations on small and intermediate length scales. At large separations where structure becomes random, an apparent power law decay with an exponent of approximately -2.2 is observed. For a moderately dense suspension where local structural correlations are essentially absent, this same apparent power law decay is observed over all probed interparticle separations. A microscopic nonhydrodynamic theory is constructed for the dynamic cross correlations which is based on interparticle frictional effects and effective structural forces. Hydrodynamics enters only via setting the very short-time single-particle self-diffusion constant. No-adjustable-parameter quantitative predictions of the theory for the dynamic cross correlations are in good agreement with experiment over all length scales. The origin of the long-range apparent power law is the influence of the constraint of fixed interparticle separation on the amplitude of the mean square force exerted on the two tagged particles by the surrounding fluid. The theory is extended to study high-packing-fraction 3D hard sphere fluids. The same pattern of an oscillatory exponential form of the dynamic cross correlation function is predicted in the structural regime, but the long-range tail decays faster than in monolayers with an exponent of -3.

  3. Aspect ratio effects on neoclassical tearing modes from comparison between DIII-D and National Spherical Torus Experiment

    NASA Astrophysics Data System (ADS)

    La Haye, R. J.; Buttery, R. J.; Gerhardt, S. P.; Sabbagh, S. A.; Brennan, D. P.

    2012-06-01

    Neoclassical tearing mode islands are sustained by helically perturbed bootstrap currents arising at finite beta from toroidal effects that trap a fraction of the particles in non-circulating orbits. DIII-D and NSTX are here operated with similar shape and cross-sectional area but almost a factor of two difference in inverse aspect ratio a /R. In these experiments, destabilized n =1 tearing modes were self-stabilized (reached the "marginal point") by reducing neutral-beam power and thus beta. The measure of the marginal island gives information on the small-island stabilizing physics that in part (with seeding) governs onset. The marginal island width on NSTX is found to be about three times the ion banana width and agrees with that measured in DIII-D, except for DIII-D modes closer to the magnetic axis, which are about two times the ion banana width. There is a balance of the helically perturbed bootstrap term with small island effects with the sum of the classical and curvature terms in the modified Rutherford equation for tearing-mode stability at the experimental marginal point. Empirical evaluation of this sum indicates that while the stabilizing effect of the curvature term is negligible in DIII-D, it is important in NSTX. The mode temporal behavior from the start of neutral-beam injection reduction also suggests that NSTX operates closer to marginal classical tearing stability; this explains why there is little hysteresis in beta between mode onset, saturation, and self-stabilization (while DIII-D has large hysteresis in beta). NIMROD code module component calculations based on DIII-D and NSTX reconstructed experimental equilibria are used to diagnose and confirm the relative importance of the stabilizing curvature effect, an advantage for low aspect ratio; the relatively greater curvature effect makes for less susceptibility to NTM onset even if the classical tearing stability index is near marginal.

  4. Polycapillary lenses for Soft-X-ray transmission: Model, comparison with experiments and potential application for tomographic measurements in tokamaks

    NASA Astrophysics Data System (ADS)

    Mazon, D.; Abadie, Q.; Dorchies, F.; Lecherbourg, L.; Mollard, A.; Malard, P.; Dabagov, S.

    2015-07-01

    In tokamaks, plasma emits as a volumetric Soft-X-ray (SXR) source. Emitted X-rays can give very useful information about plasma stability, shape and impurity content. Measuring the Soft X-ray (SXR) radiation ([0.1-20 keV]) of magnetic fusion plasmas is a standard way of accessing valuable information on particle transport and MagnetoHydroDynamic. Generally, like at Tore Supra in France, the analysis is performed with a 2D tomographic system composed of several cameras equipped with detectors like Silicon Barrier Diodes spread in periphery of the tokamak. Unfortunately, the strong constraints imposed by the environment of a tokamak reactor (high neutron fluxes, gamma and hard X-ray emission, high magnetic field and high radiofrequency powers) do not authorize to install in a close vicinity of the machine such detectors. We have thus investigated the possibility of using polycapillary lenses to transport the SXR information to several meters from the plasma, not necessarily in a straight line. The idea is to protect the SXR detector from the entire environment by a proper shielding. Different polycapillary lenses could be used for that purpose and have been tested in collaboration with CELIA (CEA-CNRS) of Bordeaux. Transmission of the order of 20% where observed for the low energetic part of the spectrum (down to 3 keV) while still 10% were observed for the remaining part (from 3 to 10 keV). In parallel a model of polycapillary transmission has been developed and validated against experiment. Results are presented confirming the great potential of polycapillary lenses for SXR transmission in tokamak plasma. Studies of the influence of geometrical parameters like diameter and curvature of the channels, on the photons transmission is also presented.

  5. Effects of high angular momentum on the unimolecular dissociation of CD2CD2OH: theory and comparisons with experiment.

    PubMed

    McKown, Benjamin G; Ceriotti, Michele; Womack, Caroline C; Kamarchik, Eugene; Butler, Laurie J; Bowman, Joel M

    2013-10-24

    This paper explores the dynamics of a highly rotationally and vibrationally excited radical, CD2CD2OH. The radical is produced from the 193 nm photodissociation of 2-bromoethanol-d4, so it is imparted with high angular momentum and high vibrational energy and subsequently dissociates to several product channels. This paper focuses on characterizing its angular momentum and modeling its effect on the product channels, including the HOD + vinyl-d3 product channel resulting from a frustrated dissociation of the radical originally en route to OH + ethene-d4 that instead results in D atom abstraction. Our impulsive model of the initial photodissociation shows that, for some cases, upward of 200 au of angular momentum is imparted, which greatly affects the dynamics of the competing product channels. Using a permutationally invariant potential energy surface and quasiclassical trajectories, we simulated the dissociation dynamics of CD2CD2OH and compared these results to those of Kamarchik et al. (J. Phys. Chem. Lett. 2010, 1, 3058-3065), who studied the dynamics of CH2CH2OH with zero angular momentum. We found that the recoil translational energy distribution for radicals that dissociated to OH + C2D4 matched experiment closely only when high angular momentum of the initial radical was explicitly included in the trajectory calculations. Similarly, the rate constant for dissociation changes when rotational energy was added to the vibrational energy in the initial conditions. Lastly, we applied the sketch-map dimensionality reduction technique to analyze mechanistic information leading to the vinyl + water product channel. Projecting the ab initio intrinsic reaction coordinates onto the lower dimensional space identified with sketch map offers new insight into the dynamics when one looks at the simulated trajectories in the lower dimensional space. Further analysis shows that the transition path resembles a frustrated dissociation of the OH + ethene radical adduct, followed

  6. Use the superconducting proximity effect to investigate alkali metal films and the comparison between the experiment and theory

    NASA Astrophysics Data System (ADS)

    Zhang, Manjiang

    Bilayers of Pb and the alkali metals Cs, Rb, K and Na were quench condensed on the quartz plate. The transition temperature measurement provides information about interface barriers between the Pb and the alkali metals. Such a barrier, which is not due to impurities or oxidation, is particularly large in Pb/Cs sandwiches. The thin K film is forced into an insulating state by being covered with sub-monolayers of Pb. The SPE is used to investigate the electronic change in the alkali film. The K film behaves as if its electrons are unable to carry a current in the x-y-plane but can easily move in the z-direction. This shows on the length scale of the K film thickness, the electronic properties of the film do not change noticeably during the metal-insulator transition. The superconducting proximity effect is investigated for SN-double layers in the thin film limit. In this regime, the normalized initial slope Ssn = (ds=Ts )|dTc=ddn| is independent of the thickness of the superconductor, the mean free path of the films and the transparency of the interface if it is not too small. The transition temperature Tc is compared with a numerical calculation developed in our group. The deviation between the experiment and theory decreases from the normal metal to the superconductor with a relative high transition temperature. The deviation factor decreases from 2.5 for Cu, Ag, Au, Mg to 1.5 for Cd, Zn, Al and finally no disagreement for In and Sn. A weak perpendicular magnetic field is applied on the super- and normal conductor double layers. The difference of the transition temperature dTc measured with and without magnetic field increases with increasing the normal metal thickness. A quantitative explanation is given based on the increased dephasing of the electrons in the magnetic field. Numerical calculation of the transition temperature based on the strong coupling theory is also given and compared with the experimental results.

  7. Comparison and analysis of 2-D simulation results with two implosion radiation experiments on the Los Alamos Pegasus I and Pegasus II capacitor banks

    SciTech Connect

    Peterson, D.L.; Bowers, R.L.; Lebeda, C.F.; Matuska, W.; Benage, J.; Idzorek, G.; Oona, H.; Stokes, J.; Roderick, N.F.

    1995-09-01

    Two experiments, PegI-41, conducted on the Los Alamos Pegasus I capacitor bank, and PegII-25, on the Pegasus II bank, consisted of the implosions of 13 mg (nominal), 5 cm radius, 2 cm high thin cylindrical aluminum foils resulting in soft x-ray radiation pulses from the plasma thermalization on axis. The implosions were conducted in direct-drive (no intermediate switching) mode with peak currents of about 4 MA and 5 MA respectively, and implosion times of about 2.5 {micro}s and 2.0 {micro}s. A radiation yield of about 250 kJ was measured for PegII-25. The purpose of these experiments was to examine the physics of the implosion and relate this physics to the production of the radiation pulse and to provide detailed experimental data which could be compared with 2-D radiation-magnetohydrodynamic (RMHD) simulations. Included in the experimental diagnostic suites were faraday rotation and dB/dt current measurements, a visible framing camera, an x-ray stripline camera, time-dependent spectroscopy, bolometers and XRD`S. A comparison of the results from these experiments shows agreement with 2-D simulation results in the instability development, current, and radiation pulse data, including the pulsewidth, shape, peak power and total radiation yield as measured by bolometry. Instabilities dominate the behavior of the implosion and largely determine the properties of the resulting radiation pulse. The 2-D simulations can be seen to be an important tool in understanding the implosion physics.

  8. Miscarriage with a History of Elective Abortion: A Comparison Study of the Miscarriage Experience - Women with a History of Elective Abortion Versus Women Without a History of Elective Abortion

    DTIC Science & Technology

    1990-01-01

    4 Abortion 11 Comparison of Miscarriage and Abortion 15 Possible effects of abortion on miscarriage 16 Chapter 3: Methodology 20 Design 20 Sample 20...possible effects of a history of elective abortion on the experience of miscarriage will be summarized. Conceptual Framework A review of Watson’s (1979... effect of support from significant others surrounding the experience of abortion . A self-administered questionnaire, which measured support and

  9. Subsonic and Supersonic Flutter Analysis of a Highly Tapered Swept-Wing Planform, Including Effects of Density Variation and Finite Wing Thickness, and Comparison with Experiments

    NASA Technical Reports Server (NTRS)

    Yates, Carson, Jr.

    1967-01-01

    The flutter characteristics of several wings with an aspect-ratio of 4.0, a taper ratio of 0.2, and a quarter-chord sweepback of 45 deg. have been investigated analytically for Mach numbers up to 2.0. The calculations were based on the modified-strip-analysis method, the subsonic-kernel-function method, piston theory, and quasi-steady second-order theory. Results of t h e analysis and comparisons with experiment indicated that: (1) Flutter speeds were accurately predicted by the modified strip analysis, although accuracy at t h e highest Mach numbers required the use of nonlinear aerodynamic theory (which accounts for effects of wing thickness) for the calculation of the aerodynamic parameters. (2) An abrupt increase of flutter-speed coefficient with increasing Mach number, observed experimentally in the transonic range, was also indicated by the modified strip analysis. (3) In the low supersonic range for some densities, a discontinuous variation of flutter frequency with Mach number was indicated by the modified strip analysis. An abrupt change of frequency appeared experimentally in the transonic range. (4) Differences in flutter-speed-coefficient levels obtained from tests at low supersonic Mach numbers in two wind tunnels were also predicted by the modified strip analysis and were shown to be caused primarily by differences in mass ratio. (5) Flutter speeds calculated by the subsonic-kernel-function method were in good agreement with experiment and with the results of the modified strip analysis. (6) Flutter speed obtained from piston theory and from quasi-steady second-order theory were higher than experimental values by at least 38 percent.

  10. MetMatch: A Semi-Automated Software Tool for the Comparison and Alignment of LC-HRMS Data from Different Metabolomics Experiments

    PubMed Central

    Koch, Stefan; Bueschl, Christoph; Doppler, Maria; Simader, Alexandra; Meng-Reiterer, Jacqueline; Lemmens, Marc; Schuhmacher, Rainer

    2016-01-01

    Due to its unsurpassed sensitivity and selectivity, LC-HRMS is one of the major analytical techniques in metabolomics research. However, limited stability of experimental and instrument parameters may cause shifts and drifts of retention time and mass accuracy or the formation of different ion species, thus complicating conclusive interpretation of the raw data, especially when generated in different analytical batches. Here, a novel software tool for the semi-automated alignment of different measurement sequences is presented. The tool is implemented in the Java programming language, it features an intuitive user interface and its main goal is to facilitate the comparison of data obtained from different metabolomics experiments. Based on a feature list (i.e., processed LC-HRMS chromatograms with mass-to-charge ratio (m/z) values and retention times) that serves as a reference, the tool recognizes both m/z and retention time shifts of single or multiple analytical datafiles/batches of interest. MetMatch is also designed to account for differently formed ion species of detected metabolites. Corresponding ions and metabolites are matched and chromatographic peak areas, m/z values and retention times are combined into a single data matrix. The convenient user interface allows for easy manipulation of processing results and graphical illustration of the raw data as well as the automatically matched ions and metabolites. The software tool is exemplified with LC-HRMS data from untargeted metabolomics experiments investigating phenylalanine-derived metabolites in wheat and T-2 toxin/HT-2 toxin detoxification products in barley. PMID:27827849

  11. Onset of the summer monsoon during the FGGE 1979 experiment off the East African Coast: A comparison of wind data collected by different means

    SciTech Connect

    Schott, F.; Partagas, J.F.

    1981-05-20

    During FGGE 1979, from March to July, an extensive oceanographic experiment with ships and moored stations was carried out in the Somali Current. The development of the monsoon winds off Somalia during the time of that experiment is described in a comparative analysis of standard ship wind observations, moored buoy wind measurements, low-level cloud winds, and winds from land stations. The onset 1979 is found to be of the multiple type, with northward winds off Somalia beginning around May 5 but dying down into early June; the real onset of sustained high winds starts around June 10. Cloud level wind observation numbers off Somalia decrease drastically with the monsoon onset because of lack of clouds over the quickly developing cold upwelling areas. An intercomparison of cloud level and ship winds for the period May 16 to July 6 at five offshore points shows good agreement in directions but reduction of ship wind speeds against cloud level winds off northern Somalia after the onset, which may explained by the increased vertical wind shear due to high air stability over the upwelled water and by geostrophic shear due to the strong gradients of sea surface temperature. A comparison of 3-day averages of buoy winds measured at 3-m height 30 km offshore, but still inland from the ship lane, with ship winds for the period March 3 to June 10 showed good agreement in directions but lower buoy wind speeds, which could partly be due to sensor height difference and partly due to horizontal wind shear towards the coast. Coastal stations and wind buoys near the coast are found not to be good indicators of the monsoon onset further out in the open ocean.

  12. Flutter of a uniform wing with an arbitrarily placed mass according to a differential-equation analysis and a comparison with experiment

    NASA Technical Reports Server (NTRS)

    Runyan, Harry L; Watkins, Charles E

    1950-01-01

    A method is presented for the calculation of the flutter speed of a uniform wing carrying an arbitrarily placed concentrated mass. The method, an extension of recently published work by Goland and Luke, involves the solution of the differential equations of motion of the wing at flutter speed and therefore does not require the assumption of specific normal modes of vibration. The order of the flutter determinant to be solved by this method depends upon the order of the system of differential equations and not upon the number of modes of vibration involved. The differential equations are solved by operational methods, and a brief discussion of operational methods as applied to boundary-value problems is included in one of two appendixes. A comparison is made with experiment for a wing with a large eccentrically mounted weight and good agreement is obtained. Sample calculations are presented to illustrate the method; and curves of amplitudes of displacement, torque, and shear for a particular case are compared with corresponding curves computed from the first uncoupled normal modes.

  13. Extruder scale-up assessment in the process of extrusion-spheronization: comparison of radial and axial systems by a design of experiments approach.

    PubMed

    Désiré, Amélie; Paillard, Bruno; Bougaret, Joël; Baron, Michel; Couarraze, Guy

    2013-02-01

    Scaling-up the extrusion-spheronization process involves the separate scale-up of each of the five process steps: dry mixing, granulation, extrusion, spheronization, and drying. The aim of the study was to compare two screw extrusion systems regarding their suitability for scaling-up. Two drug substances of high- and low-solubility in water were retained at different concentrations as formulation variables. Different spheronization times were tested. The productivity of the process was followed up using the extrusion rate and yield. Pellets were characterized by their size and shape, and by their structural and mechanical properties. A response surface design of experiments was built to evaluate the influence of the different variables and their interactions on each response, and to select the type of extrusion which provides the best results in terms of product quality, the one which shows less influence on the product after scale-up ("scalability") and when the formula used changes ("robustness"), and the one which allows the possibility to adjust pellet properties with spheronization variables ("flexibility"). Axial system showed the best characteristics in terms of product quality at lab and industrial scales, the best robustness at industrial scale, and the best scalability, by comparison with radial system. Axial system thus appeared as the easiest scaled-up system. Compared to lab scale, the conclusions observed at industrial scale were the same in terms of product quality, but different for robustness and flexibility, which confirmed the importance to test the systems at industrial scale before acquiring the equipment.

  14. Simulations of the quart (101-bar1)/water interface: A comparison of classical force fields, ab initi molecular dynamics, and x-ray reflectivity experiments.

    SciTech Connect

    Skelton, Adam; Fenter, Paul; Kubicki, James D.; Wesolowski, David J; Cummings, Peter T

    2011-01-01

    Classical molecular dynamics (CMD) simulations of the (1011) surface of quartz interacting with bulk liquid water are performed using three different classical force fields, Lopes et al., ClayFF, and CHARMM water contact angle (CWCA), and compared to ab initio molecular dynamics (AIMD) and X-ray reflectivity (XR) results. The axial densities of the water and surface atoms normal to the surface are calculated and compared to previous XR experiments. Favorable agreement is shown for all the force fields with respect to the position of the water atoms. Analyses such as the radial distribution functions between water and hydroxyl atoms and the average cosine of the angle between the water dipole vector and the normal of the surface are also calculated for each force field. Significant differences are found between the different force fields from such analyses, indicating differing descriptions of the structured water in the near vicinity of the surface. AIMD simulations are also performed to obtain the water and hydroxyl structure for comparison among the predictions of the three classical force fields to better understand which force field is most accurate. It is shown that ClayFF exhibits the best agreement with the AIMD simulations for water hydroxyl radial distribution functions, suggesting that ClayFF treats the hydrogen bonding more accurately.

  15. Comparison between experiment and theory in the temperature variation of film tension above the bulk isotropic transition in free-standing liquid-crystal films.

    PubMed

    Veum, M; Duelge, L; Droske, J; Nguyen, H T; Huang, C C; Mirantsev, L V

    2009-09-01

    Using differential scanning calorimetry, the transition enthalpies and temperatures for the bulk smectic-isotropic phase transition have been measured for a series of liquid-crystal compounds. For five compounds, those values were used as parameters in a microscopic mean-field model to predict the temperature dependence of the difference in free-energy density between a sample of material in a free-standing smectic film and that in the bulk. The model predicts a weak temperature dependence below the bulk clearing point and a pronounced monotonic increase with temperature above the transition temperature. The compounds used in this study were chosen specifically because they were also the subject of a previous independent experimental study [M. Veum, Phys. Rev. E 74, 011703 (2006)] that demonstrated a sudden monotonic increase in the free-standing film tension with temperature, which is qualitatively consistent with the predictions of the above-mentioned mean-field model. This study presents a direct and quantitative comparison between the predictions of the mean-field model and the results from previous tension experiments.

  16. Comparison of OH concentration measurements by DOAS and LIF during SAPHIR chamber experiments at high OH reactivity and low NO concentration

    NASA Astrophysics Data System (ADS)

    Fuchs, H.; Dorn, H.-P.; Bachner, M.; Bohn, B.; Brauers, T.; Gomm, S.; Hofzumahaus, A.; Holland, F.; Nehr, S.; Rohrer, F.; Tillmann, R.; Wahner, A.

    2012-07-01

    During recent field campaigns, hydroxyl radical (OH) concentrations that were measured by laser-induced fluorescence (LIF) were up to a factor of ten larger than predicted by current chemical models for conditions of high OH reactivity and low NO concentration. These discrepancies, which were observed in forests and urban-influenced rural environments, are so far not entirely understood. In summer 2011, a series of experiments was carried out in the atmosphere simulation chamber SAPHIR in Jülich, Germany, in order to investigate the photochemical degradation of isoprene, methyl-vinyl ketone (MVK), methacrolein (MACR) and aromatic compounds by OH. Conditions were similar to those experienced during the PRIDE-PRD2006 campaign in the Pearl River Delta (PRD), China, in 2006, where a large difference between OH measurements and model predictions was found. During experiments in SAPHIR, OH was simultaneously detected by two independent instruments: LIF and differential optical absorption spectroscopy (DOAS). Because DOAS is an inherently calibration-free technique, DOAS measurements are regarded as a reference standard. The comparison of the two techniques was used to investigate potential artifacts in the LIF measurements for PRD-like conditions of OH reactivities of 10 to 30 s-1 and NO mixing ratios of 0.1 to 0.3 ppbv. The analysis of twenty experiment days shows good agreement. The linear regression of the combined data set (averaged to the DOAS time resolution, 2495 data points) yields a slope of 1.02 ± 0.01 with an intercept of (0.10 ± 0.03) × 106 cm-3 and a linear correlation coefficient of R2 = 0.86. This indicates that the sensitivity of the LIF instrument is well-defined by its calibration procedure. No hints for artifacts are observed for isoprene, MACR, and different aromatic compounds. LIF measurements were approximately 30-40% (median) larger than those by DOAS after MVK (20 ppbv) and toluene (90 ppbv) had been added. However, this discrepancy has a

  17. Airborne Sunphotometer Measurements of Aerosol Optical Depth and Columnar Water Vapor During the Puerto Rico Dust Experiment, and Comparison with Land, Aircraft, and Satellite Measurements

    NASA Technical Reports Server (NTRS)

    Livingston, John M.; Russell, Philip B.; Reid, Jeffrey; Redemann, Jens; Schmid, Beat; Allen, Duane A.; Torres, Omar; Levy, Robert C.; Remer, Lorraine A.; Holben, Brent N.; Hipskind, R. Stephen (Technical Monitor)

    2002-01-01

    Analyses of aerosol optical depth (AOD) and columnar water vapor (CWV) measurements obtained with the six-channel NASA Ames Airborne Tracking Sunphotometer (AATS-6) mounted on a twin-engine aircraft during the summer 2000 Puerto Rico Dust Experiment are presented. In general, aerosol extinction values calculated from AATS-6 AOD measurements acquired during aircraft profiles up to 5 km ASL reproduce the vertical structure measured by coincident aircraft in-situ measurements of total aerosol number and surface area concentration. Calculations show that the spectral dependence of AOD was small (mean Angstrom wavelength exponents of approximately 0.20) within three atmospheric layers defined as the total column beneath the top of each aircraft profile, the region beneath the trade wind inversion, and the region within the Saharan Air Layer (SAL) above the trade inversion. This spectral behavior is consistent with attenuation of incoming solar radiation by large dust particles or by dust plus sea salt. Values of CWV calculated from profile measurements by AATS-6 at 941.9 nm and from aircraft in-situ measurements by a chilled mirror dewpoint hygrometer agree to within approximately 4% (0.13 g/sq cm). AATS-6 AOD values measured on the ground at Roosevelt Roads Naval Air Station and during low altitude aircraft runs over the adjacent Cabras Island aerosol/radiation ground site agree to within 0.004 to 0.030 with coincident data obtained with an AERONET Sun/sky Cimel radiometer located at Cabras Island. For the same observation times, AERONET retrievals of CWV exceed AATS-6 values by a mean of 0.74 g/sq cm (approximately 21 %) for the 2.9-3.9 g/sq cm measured by AATS-6. Comparison of AATS-6 aerosol extinction values obtained during four aircraft ascents over Cabras Island with corresponding values calculated from coincident aerosol backscatter measurements by a ground-based micro-pulse lidar (MPL-Net) located at Cabras yields a similar vertical structure above the trade

  18. Non-Destructive Geophysical Monitoring of Near-Surface Water-Content: Comparison Between GPR Velocities Obtained From Surface and Well Experiments

    NASA Astrophysics Data System (ADS)

    Mangue, M.

    2005-12-01

    data and crosswell GPR data for dry (june to july) and moist period (december to january). In dry period, the water table varies from 2 m to 3.5 m and in moist period, it varies from 1 m to 1.5 m. In each case, RMS and interval velocities were calculated from both experiments. In the moist period, both interval and RMS velocity maps reveal the same range of velocity variation. In the dry period, interval velocities for both acquisitions seem to have similar variation but discrepancies appear for RMS velocities. If we consider only the moist period, the non-destructive surface methodology can be validated. The differences in RMS velocities in the dry period, could be due to the volumetric water content which was not exactly similar in july 2002 and in june 2005. The differences could also be due to the processing techniques for multi-offset GPR profiling. To use the CRS technique, a constant surface velocity has to be chosen, and this latter could generate discrepancies in RMS velocities comparisons. A more accurate and perhaps variable, estimation of this surface velocity could provide closer RMS velocities for both acquisitions, in the dry period.

  19. Outcomes, cost comparison, and patient satisfaction during long-term central venous access in cancer patients: Experience from a Tertiary Care Cancer Institute in South India

    PubMed Central

    Babu, K. Govind; Suresh Babu, M. C.; Lokanatha, D.; Bhat, Gita R.

    2016-01-01

    Introduction: Prolonged treatment, frequent administration of chemotherapy, antibiotics and blood products in cancer patients requires long term venous access. Central venous catheters (CVC) inserted into the subclavian vein or internal jugular vein, peripherally inserted central venous catheters (PICC) and chemoport (CP) are the commonly used central venous access devices (CVAD). Aim: This study was envisaged to review our experience of CVADs over a one year period and analyze the outcome with regard to catheter life, reasons for removal, complications, patient satisfaction and cost comparison between the CVAD types in the Indian setting. Settings and Design: This was a prospective, observational study carried out in a tertiary care cancer institute. Materials and Methods: 180 CVADs placed in patients with hematological malignancies and solid tumors from January 2014 to December 2014 were included. Statistical Analysis Used: Data was analyzed using descriptive statistics, Mann Whitney U test. P <0.05 was taken as statistically significant. Results: 180 CVADs were placed in 160 patients. The median catheter indwelling period was 76 days (16 days to 313 days) for CVC, 59 days (20days – 313 days) for PICC and 137 days (70 days – 258 days) for CP. 66 out of 160 patients developed complications (41.2%). 108 complication events were noted in 66 patients. There were 40 episodes of CRBSI. Out of the 68 mechanical complications, 37 were encountered during insertion of the CVAD and 31 were during the catheter indwelling period. Out of 160 patients, 138 (86.25%) were satisfied with the CVAD. The cost incurred for CVC/PICC (INR 4,480) was lower than that for CP (INR 24,150) and it was statistically significant (P < 0.0001). Our patients were highly satisfied with the CVAD. Conclusion: Use of CVC and PICC is a safe, reliable and cost saving way of administration of chemotherapy in developing countries. The incidence of complications and catheter loss was acceptable. Our

  20. Universal properties of high-temperature superconductors from real-space pairing: t -J -U model and its quantitative comparison with experiment

    NASA Astrophysics Data System (ADS)

    Spałek, Józef; Zegrodnik, Michał; Kaczmarczyk, Jan

    2017-01-01

    Selected universal experimental properties of high-temperature superconducting (HTS) cuprates have been singled out in the last decade. One of the pivotal challenges in this field is the designation of a consistent interpretation framework within which we can describe quantitatively the universal features of those systems. Here we analyze in a detailed manner the principal experimental data and compare them quantitatively with the approach based on a single-band model of strongly correlated electrons supplemented with strong antiferromagnetic (super)exchange interaction (the so-called t -J -U model). The model rationale is provided by estimating its microscopic parameters on the basis of the three-band approach for the Cu-O plane. We use our original full Gutzwiller wave-function solution by going beyond the renormalized mean-field theory (RMFT) in a systematic manner. Our approach reproduces very well the observed hole doping (δ ) dependence of the kinetic-energy gain in the superconducting phase, one of the principal non-Bardeen-Cooper-Schrieffer features of the cuprates. The calculated Fermi velocity in the nodal direction is practically δ -independent and its universal value agrees very well with that determined experimentally. Also, a weak doping dependence of the Fermi wave vector leads to an almost constant value of the effective mass in a pure superconducting phase which is both observed in experiment and reproduced within our approach. An assessment of the currently used models (t -J , Hubbard) is carried out and the results of the canonical RMFT as a zeroth-order solution are provided for comparison to illustrate the necessity of the introduced higher-order contributions.

  1. Comparison of Global Model Results from the Carbon-Land Model Intercomparison Project (C-LAMP) with Free-Air Carbon Dioxide Enrichment (FACE) Manipulation Experiments

    SciTech Connect

    Hoffman, Forrest M; Randerson, Jim; Fung, Inez; Thornton, Peter E; Covey, Curtis; Bonan, Gordon; Running, Steven; Norby, Richard J

    2008-01-01

    Free-Air CO{sub 2} Enrichment (FACE) manipulation experiments have been carried out at a handful of sites to gauge the response of the biosphere to significant increases in atmospheric [CO{sub 2}]. Early synthesis results from four temperate forest sites suggest that the response of net primary productivity (NPP) is conserved across a broad range of productivity with a stimulation at the median of 23 {+-} 2% when the surrounding air [CO{sub 2}] was raised to 550{approx}ppm. As a part of the Carbon-Land Model Intercomparison Project (C-LAMP), a community-based model-data comparison activity, the authors have performed a global FACE modeling experiment using two terrestrial biogeochemistry modules, CLM3-CASA and CLM3-CN, coupled to the National Center for Atmospheric Research (NCAR) Community Climate System Model (CCSM). The two models were forced with an improved NCEP/NCAR reanalysis data set and reconstructed atmospheric [CO{sub 2}] and N deposition data through 1997. At the beginning of 1997 in the transient simulations, global atmospheric [CO{sub 2}] was abruptly raised to 550{approx}ppm, the target value used at the FACE sites. In the control runs, [CO{sub 2}] continued to rise following observations until 2004, after which it was held constant out to year 2100. In both simulations, the last 25 years of reanalysis forcing and a constant N deposition were applied after year 2004. Across all forest biomes, the NPP responses from both models are weaker than those reported for the four FACE sites. Moreover, model responses vary widely geographically with a decreasing trend of NPP increases from 40{sup o}N to 70{sup o}N. For CLM3-CASA, the largest responses occur in arid regions of western North America and central Asia, suggesting that responses are most strongly influenced by increased water use efficiency for this model. CLM3-CN exhibits consistently weaker responses than CLM3-CASA' with the strongest responses in central Asia, but significantly constrained by N

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

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

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

  3. Comparison of lidar-derived PM10 with regional modeling and ground-based observations in the frame of MEGAPOLI experiment

    NASA Astrophysics Data System (ADS)

    Royer, P.; Chazette, P.; Sartelet, K.; Zhang, Q. J.; Beekmann, M.; Raut, J.-C.

    2011-10-01

    An innovative approach using mobile lidar measurements was implemented to test the performances of chemistry-transport models in simulating mass concentrations (PM10) predicted by chemistry-transport models. A ground-based mobile lidar (GBML) was deployed around Paris onboard a van during the MEGAPOLI (Megacities: Emissions, urban, regional and Global Atmospheric POLlution and climate effects, and Integrated tools for assessment and mitigation) summer experiment in July 2009. The measurements performed with this Rayleigh-Mie lidar are converted into PM10 profiles using optical-to-mass relationships previously established from in situ measurements performed around Paris for urban and peri-urban aerosols. The method is described here and applied to the 10 measurements days (MD). MD of 1, 15, 16 and 26 July 2009, corresponding to different levels of pollution and atmospheric conditions, are analyzed here in more details. Lidar-derived PM10 are compared with results of simulations from POLYPHEMUS and CHIMERE chemistry-transport models (CTM) and with ground-based observations from the AIRPARIF network. GBML-derived and AIRPARIF in situ measurements have been found to be in good agreement with a mean Root Mean Square Error RMSE (and a Mean Absolute Percentage Error MAPE) of 7.2 μg m-3 (26.0%) and 8.8 μg m-3 (25.2%) with relationships assuming peri-urban and urban-type particles, respectively. The comparisons between CTMs and lidar at ~200 m height have shown that CTMs tend to underestimate wet PM10 concentrations as revealed by the mean wet PM10 observed during the 10 MD of 22.4, 20.0 and 17.5 μg m-3 for lidar with peri-urban relationship, and POLYPHEMUS and CHIMERE models, respectively. This leads to a RMSE (and a MAPE) of 6.4 μg m-3 (29.6%) and 6.4 μg m-3 (27.6%) when considering POLYPHEMUS and CHIMERE CTMs, respectively. Wet integrated PM10 computed (between the ground and 1 km above the ground level) from lidar, POLYPHEMUS and CHIMERE results have been compared

  4. Analysis and comparison of diurnal variations of cloud radiative forcing: Earth Radiation Budget Experiment and International Satellite Cloud Climatology Project results

    SciTech Connect

    Kim, Y.

    1994-10-01

    Cloud radiative forcing (CRF) is the radiative impact of clouds on the Earth`s radiation budget. This study examines the diurnal variations of CRF using the Earth Radiation Budget Experiment (ERBE) monthly hourly flux data and the flux data derived from the International Satellite Cloud Climatology Project (ISCCP) using the Goddard Institute for Space Studies general circulation model radiation code. The results for the months of April, July, and October 1985 and January 1986 are analyzed. We found that, in general, two data sets agreed. For longwave (LW) CRF the diurnal range over land is generally greater than that observed over oceans. For the 4-month averages the ERBE values are 15.8 W/sq m and 6.8 W/sq m for land and ocean, respectively, compared with the ISCCP calculated values of 18.4 W/sq m and 8.0 W/sq m, respectively. The land/ocean contrast is largely associated with changes in cloud amount and the temperature difference between surface and cloud top. It would be more important to note that the clear-sky flux (i.e., surface temperature) variabilities are shown to be a major contributor to the large variabilities over land. The maximum diurnal range is found to be in the summer hemisphere, and the minimum values in the winter hemisphere. It is also shown that the daytime maximum and the nighttime minimum are seen over large portions of land, whereas they occur at any local hour over most oceans. For shortwave (SW) CRF the daytime maximum values are about twice as large as monthly averages, and their highest frequency occurs at local noon, indicating that solar insolation is a primary factor for the diurnal variation of SW CRF. However, the comparison of the ERBE data with the ISCCP results demonstrated that the largest differences in the diurnal range and monthly mean of LW CRF were associated with tropical convergence zones, where clear-sky fluxes could be easily biased by persistent cloudiness and the inadequate treatment of the atmospheric water vapor.

  5. Analysis and comparison of diurnal variations of cloud radiative forcing: Earth Radiation Budget Experiment and International Satellite Cloud Climatology Project results

    NASA Technical Reports Server (NTRS)

    Kim, Yongseung

    1994-01-01

    Cloud radiative forcing (CRF) is the radiative impact of clouds on the Earth's radiation budget. This study examines the diurnal variations of CRF using the Earth Radiation Budget Experiment (ERBE) monthly hourly flux data and the flux data derived from the International Satellite Cloud Climatology Project (ISCCP) using the Goddard Institute for Space Studies general circulation model radiation code. The results for the months of April, July, and October 1985 and January 1986 are analyzed. We found that, in general, two data sets agreed. For longwave (LW) CRF the diurnal range over land is generally greater than that observed over oceans. For the 4-month averages the ERBE values are 15.8 W/sq m and 6.8 W/sq m for land and ocean, respectively, compared with the ISCCP calculated values of 18.4 W/sq m and 8.0 W/sq m, respectively. The land/ocean contrast is largely associated with changes in cloud amount and the temperature difference between surface and cloud top. It would be more important to note that the clear-sky flux (i.e., surface temperature) variabilities are shown to be a major contributor to the large variabilities over land. The maximum diurnal range is found to be in the summer hemisphere, and the minimum values in the winter hemisphere. It is also shown that the daytime maximum and the nighttime minimum are seen over large portions of land, whereas they occur at any local hour over most oceans. For shortwave (SW) CRF the daytime maximum values are about twice as large as monthly averages, and their highest frequency occurs at local noon, indicating that solar insolation is a primary factor for the diurnal variation of SW CRF. However, the comparison of the ERBE data with the ISCCP results demonstrated that the largest differences in the diurnal range and monthly mean of LW CRF were associated with tropical convergence zones, where clear-sky fluxes could be easily biased by persistent cloudiness and the inadequate treatment of the atmospheric water vapor.

  6. Teacher Candidates' Experiences with Clinical Teaching in Reading Instruction: A Comparison between the Professional Development School Environment and the Non-Professional Development School Environment

    ERIC Educational Resources Information Center

    Hopper, Cynthia J.

    2016-01-01

    Teacher candidates experience a variety of school settings when enrolled in teacher education methods courses. Candidates report varied experiences when in public school classrooms. This dissertation investigated clinical experiences of teacher candidates when placed in two different environments for clinical teaching. The two environments were a…

  7. Calculated neutron-induced cross sections for /sup 58,60/Ni from 1 to 20 MeV and comparisons with experiments

    SciTech Connect

    Hetrick, D.M.; Fu, C.Y.; Larson, D.C.

    1987-06-01

    Nuclear model codes were used to compute cross sections for neutron-induced reactions on both /sup 58/Ni and /sup 60/Ni for incident energies from 1 to 20 MeV. The input parameters for the model codes were determined through analysis of experimental data in this energy region. Discussion of the models used, the input data, the resulting calculations, extensive comparisons to measured data, and comparisons to the Evaluated Nuclear Data File (ENDF/B-V) for Ni (MAT 1328) are included in this report. 118 refs., 101 figs., 19 tabs.

  8. Calculated neutron-induced cross sections for /sup 52/Cr from 1 to 20 MeV and comparisons with experiments

    SciTech Connect

    Hetrick, D.M.; Fu, C.Y.; Larson, D.C.

    1987-09-15

    Nuclear model codes were used to compute cross sections for neutron-induced reactions on /sup 52/Cr for incident energies from 1 to 20 MeV. The input parameters for the model codes were determined through analysis of experimental data in this energy region. Discussion of the models used, the input data, the resulting calculations, extensive comparisons to measured data, and comparisons to the Evaluated Nuclear Data File (ENDF/B-V) for Cr (MAT 1324) are included in this report. 103 refs., 67 figs., 12 tabs.

  9. Latino College Students at Highly Selective Institutions: A Comparison of Their College Experiences and Outcomes to Other Racial/Ethnic Groups

    ERIC Educational Resources Information Center

    Kim, Young K.; Rennick, Liz A.; Franco, Marla A.

    2014-01-01

    This study examines unique patterns of college engagement and outcomes among Latino undergraduate students attending highly selective institutions in comparison with those from other racial/ethnic groups. The study also identifies predictors of select college outcomes--that is, cognitive, affective, and civic outcomes--for this population.…

  10. Ab initio analytical Raman intensities for periodic systems through a coupled perturbed Hartree-Fock/Kohn-Sham method in an atomic orbital basis. II. Validation and comparison with experiments

    NASA Astrophysics Data System (ADS)

    Maschio, Lorenzo; Kirtman, Bernard; Rérat, Michel; Orlando, Roberto; Dovesi, Roberto

    2013-10-01

    In this work, we validate a new, fully analytical method for calculating Raman intensities of periodic systems, developed and presented in Paper I [L. Maschio, B. Kirtman, M. Rérat, R. Orlando, and R. Dovesi, J. Chem. Phys. 139, 164101 (2013)]. Our validation of this method and its implementation in the CRYSTAL code is done through several internal checks as well as comparison with experiment. The internal checks include consistency of results when increasing the number of periodic directions (from 0D to 1D, 2D, 3D), comparison with numerical differentiation, and a test of the sum rule for derivatives of the polarizability tensor. The choice of basis set as well as the Hamiltonian is also studied. Simulated Raman spectra of α-quartz and of the UiO-66 Metal-Organic Framework are compared with the experimental data.

  11. Transport Experiments

    NASA Technical Reports Server (NTRS)

    Hall, Timothy M.; Wuebbles, Donald J.; Boering, Kristie A.; Eckman, Richard S.; Lerner, Jean; Plumb, R. Alan; Rind, David H.; Rinsland, Curtis P.; Waugh, Darryn W.; Wei, Chu-Feng

    1999-01-01

    MM II defined a series of experiments to better understand and characterize model transport and to assess the realism of this transport by comparison to observations. Measurements from aircraft, balloon, and satellite, not yet available at the time of MM I [Prather and Remsberg, 1993], provide new and stringent constraints on model transport, and address the limits of our transport modeling abilities. Simulations of the idealized tracers the age spectrum, and propagating boundary conditions, and conserved HSCT-like emissions probe the relative roles of different model transport mechanisms, while simulations of SF6 and C02 make the connection to observations. Some of the tracers are related, and transport diagnostics such as the mean age can be derived from more than one of the experiments for comparison to observations. The goals of the transport experiments are: (1) To isolate the effects of transport in models from other processes; (2) To assess model transport for realistic tracers (such as SF6 and C02) for comparison to observations; (3) To use certain idealized tracers to isolate model mechanisms and relationships to atmospheric chemical perturbations; (4) To identify strengths and weaknesses of the treatment of transport processes in the models; (5) To relate evaluated shortcomings to aspects of model formulation. The following section are included:Executive Summary, Introduction, Age Spectrum, Observation, Tropical Transport in Models, Global Mean Age in Models, Source-Transport Covariance, HSCT "ANOY" Tracer Distributions, and Summary and Conclusions.

  12. Detection of the "cp4 epsps" Gene in Maize Line NK603 and Comparison of Related Protein Structures: An Advanced Undergraduate Experiment

    ERIC Educational Resources Information Center

    Swope, Nicole K.; Fryfogle, Patrick J.; Sivy, Tami L.

    2015-01-01

    A flexible, rigorous laboratory experiment for upper-level biochemistry undergraduates is described that focuses on the Roundup Ready maize line. The work is appropriate for undergraduate laboratory courses that integrate biochemistry, molecular biology, or bioinformatics. In this experiment, DNA is extracted and purified from maize kernel and…

  13. College Experiences and Outcomes among International Undergraduate Students at Research Universities in the United States: A Comparison to Their Domestic Peers

    ERIC Educational Resources Information Center

    Kim, Young K.; Collins, Christopher S.; Rennick, Liz A.; Edens, David

    2017-01-01

    Using a large dataset from a state education system, this study examined the experience of international college students in the United States as well as the connection to their cognitive, affective, and civic outcomes. The study utilized data from the 2010 University of California Undergraduate Experience Survey (UCUES) and a sample of 35,146…

  14. Calculation of Aerodynamic Loading and Twist Characteristics of a Flexible Wing at Mach Numbers Approaching 1.0 and Comparison with Experiment

    NASA Technical Reports Server (NTRS)

    Mugler, John P., Jr.

    1960-01-01

    An iteration method is presented by which the detailed aerodynamic loading and twist characteristics of a flexible wing with known elastic properties may be calculated. The method is applicable at Mach numbers approaching 1.0 as well as at subsonic Mach numbers. Calculations were made for a wing-body combination; the wing was swept back 45 deg and had an aspect ratio of 4. Comparisons were made with experimental results at Mach numbers from.0.80 to 0.98.

  15. Summarizing EC50 estimates from multiple dose-response experiments: a comparison of a meta-analysis strategy to a mixed-effects model approach.

    PubMed

    Jiang, Xiaoqi; Kopp-Schneider, Annette

    2014-05-01

    Dose-response studies are performed to investigate the potency of a compound. EC50 is the concentration of the compound that gives half-maximal response. Dose-response data are typically evaluated by using a log-logistic model that includes EC50 as one of the model parameters. Often, more than one experiment is carried out to determine the EC50 value for a compound, requiring summarization of EC50 estimates from a series of experiments. In this context, mixed-effects models are designed to estimate the average behavior of EC50 values over all experiments by considering the variabilities within and among experiments simultaneously. However, fitting nonlinear mixed-effects models is more complicated than in a linear situation, and convergence problems are often encountered. An alternative strategy is the application of a meta-analysis approach, which combines EC50 estimates obtained from separate log-logistic model fitting. These two proposed strategies to summarize EC50 estimates from multiple experiments are compared in a simulation study and real data example. We conclude that the meta-analysis strategy is a simple and robust method to summarize EC50 estimates from multiple experiments, especially suited in the case of a small number of experiments.

  16. Dynamics of the C(1D)+D2 reaction: a comparison of crossed molecular-beam experiments with quasiclassical trajectory and accurate statistical calculations.

    PubMed

    Balucani, Nadia; Capozza, Giovanni; Segoloni, Enrico; Russo, Andrea; Bobbenkamp, Rolf; Casavecchia, Piergiorgio; Gonzalez-Lezana, Tomas; Rackham, Edward J; Bañares, Luis; Aoiz, F Javier

    2005-06-15

    In this paper we report a combined experimental and theoretical study on the dynamics of the insertion reaction C((1)D)+D(2) at 15.5 kJ mol(-1) collision energy. Product angular and velocity distributions have been obtained in crossed beam experiments and quasiclassical trajectory (QCT) and rigorous statistical calculations have been performed on the recent and accurate ab initio potential energy surface of Bussery-Honvault, Honvault, and Launay at the energy of the experiment. The molecular-beam results have been simulated using the theoretical calculations. Good agreement between experiment and both QCT and statistical predictions is found.

  17. Experiments with powdered CMN thermometers between 10 mK and 4K, and a comparison with an NBS SRM 768 fixed-point device

    SciTech Connect

    Fogle, W.E.; Hornung, E.W.; Mayberry, M.C.; Phillips, N.E.

    1981-08-01

    Comparison of a powdered CMN thermometer with an NBS fixed point device demonstrates an internal inconsistency in the T/sub c/'s assigned to the fixed point device. T/sub c/'s between 100 and 200 mK are in excellent agreement with a temperature scale interpolated between He vapor pressure temperatures and nuclear orientation temperatures, but there is a discrepancy of 8% at the 15 mK point. Evidence for different susceptibility-temperature relations for superficially similar CMN thermometers is also presented.

  18. Comparison of Real World Side Impact/Rollover Collisions With and Without Thorax Airbag/Head Protection System: A First Field Experience Study

    PubMed Central

    Baur, Peter; Lange, Wolfgang; Messner, Georg; Rauscher, Stefan; Pieske, Oliver

    2000-01-01

    After the introduction of the Thorax Airbag (TA) and the Head Protection System (HPS) by BMW there has been a significant reduction of injuries in real-world collisions. Comparison of similar collisions (in-depth collision analyses) of vehicles with and without HPS/TA indicates that the effectiveness of the system was credible. Minor injuries (AIS 1) increase while serious injuries (AIS 3+) are reduced. Based on the limited cases available, a proper statistical sampling could not be achieved at this time, however the results are to be understood as indicative of a trend. PMID:11558083

  19. Control law parameterization for an aeroelastic wind-tunnel model equipped with an active roll control system and comparison with experiment

    NASA Technical Reports Server (NTRS)

    Perry, Boyd, III; Dunn, H. J.; Sandford, Maynard C.

    1988-01-01

    Nominal roll control laws were designed, implemented, and tested on an aeroelastically-scaled free-to-roll wind-tunnel model of an advanced fighter configuration. The tests were performed in the NASA Langley Transonic Dynamics Tunnel. A parametric study of the nominal roll control system was conducted. This parametric study determined possible control system gain variations which yielded identical closed-loop stability (roll mode pole location) and identical roll response but different maximum control-surface deflections. Comparison of analytical predictions with wind-tunnel results was generally very good.

  20. Comparison of batch, stirred flow chamber, and column experiments to study adsorption, desorption and transport of carbofuran within two acidic soils.

    PubMed

    Bermúdez-Couso, Alipio; Fernández-Calviño, David; Rodríguez-Salgado, Isabel; Nóvoa-Muñoz, Juan Carlos; Arias-Estévez, Manuel

    2012-06-01

    Different methods (batch, column and stirred flow chamber experiments) used for adsorption and desorption of carbofuran studies were compared. All tested methods showed that the carbofuran adsorption was higher in the soil with the higher organic matter content, whereas the opposite behaviour was observed for the percentage of carbofuran desorbed. However, different methods have revealed some discrepancies in carbofuran adsorption/desorption kinetics. Although batch method showed interesting data on equilibrium experiments, such as a low heterogeneity for the carbofuran adsorption sites independent of soil organic matter content, it had some disadvantages for carbofuran adsorption/desorption kinetic studies. The disadvantages were related with the excessive limitations of this method on kinetics, i.e., no difference could be detected between different soils. However, with column and stirred flow chamber methods the carbofuran adsorption/desorption kinetics of different soils could be compared. Moreover, the absolute values of carbofuran adsorption/desorption and its rate were higher in the stirred flow chamber than in the batch and column experiments. Using stirred flow chamber experiments the carbofuran desorption was significantly faster than its adsorption, whereas carbofuran using column experiments they were similar. These discrepancies should be considered when the results obtained only with one method is discussed.

  1. Dissociative disorders and possession experiences in Israel: a comparison of opiate use disorder patients, Arab women subjected to domestic violence, and a nonclinical group.

    PubMed

    Somer, Eli; Ross, Colin; Kirshberg, Revital; Bakri, Rana Shawahdy; Ismail, Shefa

    2015-02-01

    This study examined the association between exposure to domestic violence and dissociative symptoms. A sample of 68 Israeli opiate use disorder patients in recovery, 80 battered Arab Israeli women, and 103 respondents from a community sample participated in structured interviews that included the Dissociative Disorders Interview Schedule (DDIS), the Dissociative Trance Disorder Interview Schedule (DTDIS), and the Dissociative Experiences Scale (DES). As predicted, community participants reported significantly less exposure to traumatizing events and lower levels of dissociative psychopathology than individuals sampled from specialized treatment centers. In all, 91% of battered female participants were taxon-positive for dissociative disorder with 1 of every 2 respondents reporting symptoms corresponding to dissociative amnesia and depersonalization disorder, suggesting that this group may be particularly vulnerable to dissociative psychopathology. Extrasensory and paranormal experiences (ESP) and dissociative trance disorder experiences were strongly related to dissociative experiences and features of dissociative identity disorder (DID). These statistical associations suggest that dissociative disorders and ESP/trance experiences may share an underlying construct. Further research is needed on trauma and dissociation among female victims of domestic abuse in patriarchal, collectivist societies, particularly in the Arab world.

  2. The effect of experience and training on the diagnosis of approximal coronal caries from bitewing radiographs. A Swiss-American comparison.

    PubMed

    Firestone, A R; Lussi, A; Weems, R A; Heaven, T J

    1994-01-01

    The purpose of the present study was to compare the development of skills in the radiographic diagnosis of approximal coronal caries. Swiss (Bern) and American (Alabama) dental students with and without clinical experience, Swiss general practitioners, and Swiss and American dental school faculty viewed bitewing radiographic films of 13 teeth. The observers examined the 26 approximal surfaces on the radiographic films and responded, on a five point certainty scale, whether approximal caries was present. Mean sensitivity ranged from a low of 0.59 for American faculty to a high of 0.80 for Swiss students with clinical experience, mean specificity ranged from 0.84 for Swiss pre-clinical students to 0.95 for American faculty. For a summary measure of accuracy, i.e., area under the receiver operating characteristic (ROC) curve, the scores for student observers tended to increase with experience. The scores for Swiss and American students with clinical experience and faculty did not differ significantly. Inter-examiner agreement (Kappa) could only be characterized as moderate at best. Formal didactic instruction and clinical experience produced dental students with skills in the diagnosis of approximal caries from bitewing radiographs similar to that of faculty dentists.

  3. The dynamics of the O(1D) + HCl --> OH + Cl reaction at a 0.26 eV collision energy: a comparison between theory and experiment.

    PubMed

    Bargueño, P; Jambrina, P G; Alvariño, J M; Hernández, M L; Aoiz, F J; Menéndez, M; Verdasco, E; González-Lezana, T

    2009-12-31

    The dynamics of the O((1)D) + HCl(v = 0, j = 0) --> Cl + OH reaction at a 0.26 eV collision energy has been investigated by means of a quasiclassical trajectory (QCT) and statistical quantum and quasiclassical methods. State-resolved cross sections and Cl atom velocity distributions have been calculated on two different potential energy surfaces (PESs): the H2 surface (Martinez et al. Phys. Chem. Chem. Phys. 2000, 2, 589) and the latest surface by Peterson, Bowman, and co-workers (PSB2) (J. Chem. Phys. 2000, 113, 6186). The comparison with recent experimental results reveals that the PSB2 PES manages to describe correctly differential cross sections and the velocity distributions of the departing Cl atom. The calculations on the H2 PES seem to overestimate the OH scattering in the forward direction and the fraction of Cl at high recoil velocities. Although the comparison of the corresponding angular distributions is not bad, significant deviations with a statistical description are found, thus ruling out a complex-forming mechanism as the dominant reaction pathway. However, for the ClO + H product channel, the QCT and statistical predictions are found to be in good agreement.

  4. Angular distribution for electron excitation of the 4(2)S yields 4(2)P transition in Zn II - Comparison of experiment and theory

    NASA Technical Reports Server (NTRS)

    Chutjian, A.; Msezane, A. Z.; Henry, R. J. W.

    1983-01-01

    Differential electron-scattering cross sections for inelastic excitation of an ion have been measured for the first time. Experiments were carried out in a cross electron-ion beam geometry for the 4(2)S yields 4(2)P transition in Zn II at 75 eV. In addition, differential cross sections were calculated at energies between 15 and 100 eV in a five-state close-coupling approximation in which 4s, 4p, 3d(9)4s(2), 5s, and 4 d states were included. Agreement in shape between theory and experiment at 75 eV is excellent.

  5. Comparison of Environmental Attitudes and Experiences of Five-Year-Old Children Receiving Preschool Education in the Village and City Centre

    ERIC Educational Resources Information Center

    Durkan, Nazmi; Güngör, Hande; Fetihi, Leyla; Erol, Ahmet; Gülay Ogelman, Hülya

    2016-01-01

    The purpose of the study is to compare environmental attitudes and experiences of five-year-old children receiving preschool education in the village and city centre. The first group comprised 54 five-year-old children who received preschool education and attended kindergartens of two primary schools in the Karateke and Kocabas villages of Honaz…

  6. Teachers' and Parents' Roles in the Sexuality Education of Primary School Children: A Comparison of Experiences in Leeds, UK and in Sydney, Australia

    ERIC Educational Resources Information Center

    Walker, Joy; Milton, Jan

    2006-01-01

    There is little international research focusing on parents' and teachers' roles in sexuality education during children's primary school years. This paper focuses on teachers' and parents' key experiences as sexuality educators of primary-school-age children in both Leeds, UK and in Sydney, Australia. Based on research findings from both the United…

  7. Comparisons of Internet-Based and Face-to-Face Learning Systems Based on "Equivalency of Experiences" According to Students' Academic Achievements and Satisfactions

    ERIC Educational Resources Information Center

    Karatas, Sercin; Simsek, Nurettin

    2009-01-01

    The purpose of this study is to determine whether "equivalent learning experiences" ensure equivalency, in the Internet-based and face-to-face interaction methods on learning results and student satisfaction. In the experimental process of this study, the effect of the Internet-based and face-to-face learning on the equivalency in…

  8. Comparison of airborne passive and active L-band System (PALS) brightness temperature measurements to SMOS observations during the SMAP validation experiment 2012 (SMAPVEX12)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of SMAP (Soil Moisture Active Passive) Validation Experiment 2012 (SMAPVEX12) campaign was to collect data for the pre-launch development and validation of SMAP soil moisture algorithms. SMAP is a National Aeronautics and Space Administration’s (NASA) satellite mission designed for the m...

  9. A Comparison of the Developmental Experiences of Elite and Sub-Elite Swimmers: Similar Developmental Histories Can Lead to Differences in Performance Level

    ERIC Educational Resources Information Center

    Johnson, Michael B.; Tenenbaum, Gershon; Edmonds, William A.; Castillo, Yvonne

    2008-01-01

    The current study fills a void in the literature that investigates the factors required for elite athlete development. Previous studies have (a) illustrated psychological and physiological differences between elites and non-elites; "or" (b) described the psychological and physiological developmental experiences of elite performers. The…

  10. A Comparison of Compliance and Aspirational Accreditation Models: Recounting a University's Experience with Both a Taiwanese and an American Accreditation Body

    ERIC Educational Resources Information Center

    Cheng, Nellie S.

    2015-01-01

    Despite the widespread adoption of accreditation processes and the belief in their effectiveness for improving educational quality, the search for good accreditation practices remains a critical issue. This article recounts one university's experiences when simultaneously undergoing the accreditation processes of both the Middle States Commission…

  11. Biodegradation of hydrocarbons vapors: Comparison of laboratory studies and field investigations in the vadose zone at the emplaced fuel source experiment, Airbase Vaerløse, Denmark.

    PubMed

    Höhener, Patrick; Dakhel, Nathalie; Christophersen, Mette; Broholm, Mette; Kjeldsen, Peter

    2006-12-15

    The natural attenuation of volatile organic compounds (VOCs) in the unsaturated zone can only be predicted when information about microbial biodegradation rates and kinetics are known. This study aimed at determining first-order rate coefficients for the aerobic biodegradation of 13 volatile petroleum hydrocarbons which were artificially emplaced as a liquid mixture during a field experiment in an unsaturated sandy soil. Apparent first-order biodegradation rate coefficients were estimated by comparing the spatial evolution of the resulting vapor plumes to an analytical reactive transport model. Two independent reactive numerical model approaches have been used to simulate the diffusive migration of VOC vapors and to estimate degradation rate coefficients. Supplementary laboratory column and microcosm experiments were performed with the sandy soil at room temperature under aerobic conditions. First-order kinetics adequately matched the lab column profiles for most of the compounds. Consistent compound-specific apparent first-order rate coefficients were obtained by the three models and the lab column experiment, except for benzene. Laboratory microcosm experiments lacked of sensitivity for slowly degrading compounds and underestimated degradation rates by up to a factor of 5. Addition of NH3 vapor was shown to increase the degradation rates for some VOCs in the laboratory microcosms. All field models suggested a significantly higher degradation rate for benzene than the rates measured in the lab, suggesting that the field microbial community was superior in developing benzene degrading activity.

  12. Diffusivity of the deuterated hydrogen molecule HD in NaA zeolite by neutron scattering experiment. Comparison with H2 in NaA

    NASA Astrophysics Data System (ADS)

    Cohen De Lara, Evelyne; Kahn, Rémi

    1992-01-01

    The diffusion of HD in NaA is studied by incoherent neutron scattering, in order to be compared with H2. The behavior of HD is similar to the one of H2: Translational motion in a nonrestricted volume and liquidlike diffusivity. The diffusion model which fits the width of the quasielastic scattering in the entire (q,T) range gives a mean length for the isotropic jump l¯=3.3 Å, shorter than the one of H2 (3.9 Å), and equivalent values of the time τ0 between jumps. The comparison of the Arrhenius plots of DH2 and DHD leads to the conclusion that quantum effects have to be taken into account.

  13. Spectral shapes of Ar-broadened HCl lines in the fundamental band by classical molecular dynamics simulations and comparison with experiments

    SciTech Connect

    Tran, H.; Domenech, J.-L.

    2014-08-14

    Spectral shapes of isolated lines of HCl perturbed by Ar are investigated for the first time using classical molecular dynamics simulations (CMDS). Using reliable intermolecular potentials taken from the literature, these CMDS provide the time evolution of the auto-correlation function of the dipole moment, whose Fourier-Laplace transform leads to the absorption spectrum. In order to test these calculations, room temperature spectra of various lines in the fundamental band of HCl diluted in Ar are measured, in a large pressure range, with a difference-frequency laser spectrometer. Comparisons between measured and calculated spectra show that the CMDS are able to predict the large Dicke narrowing effect on the shape of HCl lines and to satisfactorily reproduce the shapes of HCl spectra at different pressures and for various rotational quantum numbers.

  14. Conference on Complex Turbulent Flows: Comparison of Computation and Experiment, Stanford University, Stanford, CA, September 14-18, 1981, Proceedings. Volume 2 - Taxonomies, reporters' summaries, evaluation, and conclusions

    NASA Technical Reports Server (NTRS)

    Kline, S. J. (Editor); Cantwell, B. J. (Editor); Lilley, G. M.

    1982-01-01

    Computational techniques for simulating turbulent flows were explored, together with the results of experimental investigations. Particular attention was devoted to the possibility of defining a universal closure model, applicable for all turbulence situations; however, conclusions were drawn that zonal models, describing localized structures, were the most promising techniques to date. The taxonomy of turbulent flows was summarized, as were algebraic, differential, integral, and partial differential methods for numerical depiction of turbulent flows. Numerous comparisons of theoretically predicted and experimentally obtained data for wall pressure distributions, velocity profiles, turbulent kinetic energy profiles, Reynolds shear stress profiles, and flows around transonic airfoils were presented. Simplifying techniques for reducing the necessary computational time for modeling complex flowfields were surveyed, together with the industrial requirements and applications of computational fluid dynamics techniques.

  15. On the dynamics of the H{sup +}+D{sub 2}(v=0,j=0){yields}HD+D{sup +} reaction: A comparison between theory and experiment

    SciTech Connect

    Carmona-Novillo, Estela; Gonzalez-Lezana, Tomas; Roncero, Octavio; Honvault, Pascal; Launay, Jean-Michel; Bulut, Niyazi; Javier Aoiz, F.; Banares, Luis; Trottier, Alexandre; Wrede, Eckart

    2008-01-07

    The H{sup +}+D{sub 2}(v=0,j=0){yields}HD+D{sup +} reaction has been theoretically investigated by means of a time independent exact quantum mechanical approach, a quantum wave packet calculation within an adiabatic centrifugal sudden approximation, a statistical quantum model, and a quasiclassical trajectory calculation. Besides reaction probabilities as a function of collision energy at different values of the total angular momentum, J, special emphasis has been made at two specific collision energies, 0.1 and 0.524 eV. The occurrence of distinctive dynamical behavior at these two energies is analyzed in some detail. An extensive comparison with previous experimental measurements on the Rydberg H atom with D{sub 2} molecules has been carried out at the higher collision energy. In particular, the present theoretical results have been employed to perform simulations of the experimental kinetic energy spectra.

  16. Comparison of the frequency estimation of the DORIS/Jason2 oscillator thanks to the onboard DIODE and Time Transfer by Laser Link experiment

    NASA Astrophysics Data System (ADS)

    Jayles, C.; Exertier, P.; Martin, N.; Chauveau, J. P.; Samain, E.; Tourain, C.; Auriol, A.; Guillemot, P.

    2016-12-01

    The main applications for DORIS are precise orbit determination, and precise Geodesy. Onboard Jason-2 for instance, the DORIS tracking component is the French contribution to the precise orbit determination capability, a key capability for altimetry product scientific result accuracy. T2L2 is a time transfer technique based on the propagation of light pulses for synchronization between two clocks. Hosting T2L2 on-board Jason-2 was to allow for very fine DORIS USO (Ultra-Stable Oscillator) frequency monitoring, and for this purpose T2L2 was connected to the DORIS USO. Thanks to the continuous tracking of T2L2/Jason-2 by the Laser Ranging network it is possible to monitor the USO for several days, weeks, and even much longer, and thus to also compare with the DIODE (the DORIS on-board orbit determination software) frequency bias estimates. The DORIS USO frequency biases estimate comparison between two independent systems, T2L2 and DIODE, can be of benefit to both, allowing the accuracies of both systems to be better understood, and for improvements to be made to both systems. Such comparison is the central topic of the present paper. T2L2 monitors the DORIS on-board USO frequency with an accuracy of much better than 10-12 which is the specification for the Doppler instrumentation. The paper investigates the limits of the DORIS-DIODE frequency bias estimates using T2L2, showing that USO frequency compliance accuracy of 10-12 has been reached.

  17. Monitoring the interaction of hydraulic fracturing fluid with Marcellus Shale using Sr isotopes: a comparison of laboratory experiments with field scale observations (Invited)

    NASA Astrophysics Data System (ADS)

    Wall, A. J.; Hakala, A.; Marcon, V.; Joseph, C.

    2013-12-01

    Strontium isotopes have the potential to be an effective tool for differentiating Marcellus Shale derived-fluids from other sources in surface and ground waters (Chapman et al. 2012, doi: 10.1021/es204005g). Water that is co-produced during gas extraction is likely influenced by fluid/rock interactions during hydraulic fracturing (HF) and monitoring changes in Sr isotope ratios can provide insight into reactions occurring within the shale formation. However, questions persist as to what controls the Sr isotopic composition of Marcellus Shale fluids, especially during HF. Here we compare laboratory experiments, simulating the dissolution of the Marcellus Shale during HF, with a time-series of water samples taken from a Marcellus Shale gas wells after HF has occurred. For the laboratory experiments, a core sample of Marcellus Shale from Greene County, PA was crushed and placed into a high P and T reaction vessel. Solutions were added in two different experiments: one with synthetic brine, and another using brine+HF fluid. The HF fluid was made up of components listed on fracfocus.org. Experiments were run for ~16 days at 27.5 MPa and 130oC. Aqueous samples were periodically removed for analysis and Sr isotope ratios were measured by MC-ICP-MS. Using just brine, the pH of the solution decreased from 7.6 to 5.3 after 24 hrs, then reached a steady state at ~6.1. Sr/Ca molar ratios in the fluid started at 2.3 after 24 hours and decreased to 1.8 over ~16 days. During this time only 6% of the total inorganic carbon (TIC) dissolved from the shale. The ɛSr values started at +43.2 and decreased to +42.4. In the experiment using brine+HF fluid, the pH started at 1.8 and rose slowly to a steady value of 5.6 by day 6. The Sr and Ca concentrations were higher than the brine experiment, but the Sr/Ca ratios remained lower at ~0.3 through the experiment. The increased Ca release, as well as the dissolution of over 60% of the TIC, suggests the dissolution of a carbonate mineral

  18. Reflectance Anisotropy Spectroscopy(RAS) of Si(111)-(3x1)-Ag and Si(111)-c(12x2): Comparison of hybrid density functional theory and experiment

    NASA Astrophysics Data System (ADS)

    Jorgji, Sofia; McGilp, John; Patterson, Charles

    2013-03-01

    The atomic and electronic structures of the Si(111)-(3x1)-Ag surface have been investigated extensively by LEED, STM and electron spectroscopies. The atomic structure is believed to be a honeycomb chain plus channel (HCC) structure in which channels containing Ag atoms are separated by Si in honeycomb chains. Here we compare results of previous reflectance anisotropy spectroscopy (RAS) experiments with hybrid DFT simulations for the HCC structure. Results of RAS simulations are in very good agreement with RAS experiments and indicate that the HCC structure is likely to be correct. Surface state features responsible for the RAS signal are identified and the effect of dimerisation of Ag chains on the RAS spectrum is considered. This work was supported by the Irish HEA under PRTLI-V

  19. Comparison of Subjective Experiences and Effectiveness of First-Generation Long-Acting Injectable Antipsychotics and Risperidone Long-Acting Injectables in Patients With Schizophrenia.

    PubMed

    Chen, Wen-Yin; Lin, Shih-Ku

    2016-10-01

    We conducted a cross-sectional study to compare the subjective experiences and clinical effects of first-generation long-acting injectable (FGA-LAI) antipsychotics with those of risperidone long-acting injectables (RIS-LAIs) in 434 schizophrenia patients. Compared with the RIS-LAI group, the patients treated with FGA-LAIs had a significantly longer duration of illness and LAI treatment and were older. Our results suggest that patients treated with FGA-LAI have more satisfactory subjective experiences compared with patients treated with RIS-LAI and that both FGA-LAI and RIS-LAI treatments can prevent relapses and hospitalization. Additional longitudinal studies determining the long-term benefits of RIS-LAI are warranted.

  20. Chemistry Experiments

    NASA Technical Reports Server (NTRS)

    Brasseur, Guy; Remsberg, Ellis; Purcell, Patrick; Bhatt, Praful; Sage, Karen H.; Brown, Donald E.; Scott, Courtney J.; Ko, Malcolm K. W.; Tie, Xue-Xi; Huang, Theresa

    1999-01-01

    The purpose of the chemistry component of the model comparison is to assess to what extent differences in the formulation of chemical processes explain the variance between model results. Observed concentrations of chemical compounds are used to estimate to what degree the various models represent realistic situations. For readability, the materials for the chemistry experiment are reported in three separate sections. This section discussed the data used to evaluate the models in their simulation of the source gases and the Nitrogen compounds (NO(y)) and Chlorine compounds (Cl(y)) species.

  1. A comparison of theory and experiment for coupled rotor-body stability of a hingeless rotor model in hover under simulated vacuum conditions

    NASA Technical Reports Server (NTRS)

    Bousman, William G.

    1988-01-01

    Two cases were selected for correlation from an experiment that examined the aeromechanical stability of a small-scale model rotor that used tantalum rods instead of blades to simulate vacuum conditions. The first case involved body roll freedom only while the second case included body pitch and roll degrees of freedom together. Analyses from Hughes Helicopters and the U.S. Army Aeromechanics Laboratory were compared with the data and the correlations ranged from poor to good.

  2. A Comparison of Sequential Assimilation Schemes for Ocean Prediction with the HYbrid Coordinate Ocean Model (HYCOM): Twin Experiments with Static Forecast Error Covariances

    DTIC Science & Technology

    2011-01-01

    experiments here is implemented as follows. First, the matrix C is computed: C={ HSf )R-\\ HSf )T (A.3) In the next step, the innovation is computed in the...reduced space ö = ( HSf )R-\\y-Hxf) (A.4) and is followed by a correction in the reduced space y-p + q-’J (A.5) As in EnOI, a local analysis for each grid

  3. The Effects of Corona on Current Surges Induced on Conducting Lines by EMP (Electromagnetic Pulse): A Comparison of Experiment Data with Results of Analytic Corona Models

    DTIC Science & Technology

    1987-09-01

    that produced by a nuclear detonation above the earth’s atmosphere, was performed in March, 1986 at Kirtland Air Force Base near Albuquerque, New Mexico ...March, 1986, an EMP corona experiment was conducted at Kirtland Air Force Base, New Mexico . This work was funded in part by the DOE and by the Defense...through ORNL and by the Defense Nuclear Agency (DNA), was conducted at Kirtland Air Force Base in New Mexico . The data obtained in this measurement program

  4. Reactions to First Postpubertal Female Same-Sex Sexual Experience in the Kinsey Sample: A Comparison of Minors with Peers, Minors with Adults, and Adults with Adults.

    PubMed

    Rind, Bruce

    2016-10-25

    This study examined reactions to first postpubertal same-sex sexual experience in the Kinsey female same-sex sample (consisting of females with extensive postpubertal same-sex experience) as a function of participant and partner ages. As such, it complemented the Rind and Welter (2016) study, which examined the same in the Kinsey male same-sex sample. Data were collected by Kinsey interviewers between 1939 and 1961 (M year = 1947). Girls under 18 (M age = 14.9), whose sexual experience was with a woman (M age = 26.3), reacted positively just as often as girls under 18 (M age = 14.1) with peers (M age = 15.0) and women (M age = 22.7) with women (M age = 26.3). The positive-reaction rates were, respectively, 85, 82, and 79 %. In a finer-graded analysis, younger adolescent girls (≤14) (M age = 12.8) with women (M age = 27.4) had a high positive-reaction rate (91 %), a rate reached by no other group. For women (M age = 22.2) with same-aged peers (M age = 22.3), this rate was 86 %. Girls with peers or women had no emotionally negative reactions (e.g., fear, disgust, shame, regret); women with women rarely did. Results contradicted prevailing clinical, legal, and lay beliefs that minor-adult sex is inherently traumatic and would be distinguished as such compared to age-concordant sex. The findings are discussed in terms of the time period in which the sexual experiences occurred.

  5. Experience with exchange and archiving of raw data: comparison of data from two diffractometers and four software packages on a series of lysozyme crystals.

    PubMed

    Tanley, Simon W M; Schreurs, Antoine M M; Helliwell, John R; Kroon-Batenburg, Loes M J

    2013-02-01

    The International Union of Crystallography has for many years been advocating archiving of raw data to accompany structural papers. Recently, it initiated the formation of the Diffraction Data Deposition Working Group with the aim of developing standards for the representation of these data. A means of studying this issue is to submit exemplar publications with associated raw data and metadata. A recent study on the effects of dimethyl sulfoxide on the binding of cisplatin and carboplatin to histidine in 11 different lysozyme crystals from two diffractometers led to an investigation of the possible effects of the equipment and X-ray diffraction data processing software on the calculated occupancies and B factors of the bound Pt compounds. 35.3 Gb of data were transferred from Manchester to Utrecht to be processed with EVAL. A systematic comparison shows that the largest differences in the occupancies and B factors of the bound Pt compounds are due to the software, but the equipment also has a noticeable effect. A detailed description of and discussion on the availability of metadata is given. By making these raw diffraction data sets available via a local depository, it is possible for the diffraction community to make their own evaluation as they may wish.

  6. Breakthrough of two pesticides into tile drain and shallow groundwater: comparison of tile drain reaction and soil profiles within a field scale irrigation experiment

    NASA Astrophysics Data System (ADS)

    Klaus, Julian; Zehe, Erwin; Elsner, Martin; Palm, Juliane; Schneider, Dorothee; Schröder, Boris; Steinbeiss, Sibylle; West, Stephanie

    2010-05-01

    Preferential flow in macropores is a key process which strongly affects infiltration and may cause rapid transport of pesticides into depths of 80 to 150 cm. At these depths they experience a much slower degradation, may leach into shallow groundwater or enter a tile-drain and are transported into surface water bodies. Therefore, preferential transport might be an environmental problem, if the topsoil is bypassed, which has been originally thought to act as a filter to protect the subsoil and shallow groundwater. To investigate the behaviour of two pesticides with different chemical characteristics and to compare their transport behaviour in soil and into the tile drain an irrigation experiment was performed on a 400 m² field site. The experimental plot is located in the Weiherbach valley, south-west Germany, which basic geology consists of Loess and Keuper layers, the soil at the test site is a gleyic Colluvisol. The distance of the irrigation site to the Weiherbach brook is approximately 12 m, the field is drained with a tile-drain in about 1.2 m depth and shows discharge over the entire year. Three hours before the irrigation started, the farmer applied a pesticide solution consisting of Isoproturon (80 g) and Flufenacet (20 g) (IPU and FLU) according to conventional agricultural practice on the field plot. The irrigation took place in three time blocks (80 min, 60 min, 80 min) with in total 33.6 mm of precipitation. During the first block 1600 g of Bromide were mixed in the irrigation water. The drainage outlet was instrumented with a pressure probe. About 50 water samples ware taken during the experimental day, and several samples more the days after the experiment. They were analysed for the pesticides, bromide and water isotopes. In the two days after the experiment three soil profiles were excavated and soil samples were taken on a 10x10 cm² scheme. One week after the experiment two additional profiles were excavated. The soil was analysed for IPU, FLU

  7. Comparisons of Cn2 measurements and power-in-fiber data from two long-path free-space optical communication experiments

    NASA Astrophysics Data System (ADS)

    Parenti, Ronald R.; Michael, Steven; Roth, Jeffrey M.; Yarnall, Timothy M.

    2010-08-01

    Over a two-year period beginning in early 2008, MIT Lincoln Laboratory conducted two free-space optical communication experiments designed to test the ability of spatial beam diversity, symbol encoding, and interleaving to reduce the effects of turbulence-induced scintillation. The first of these exercises demonstrated a 2.7 Gb/s link over a ground-level 5.4 km horizontal path. Signal detection was accomplished through the use of four spatially-separated 12 mm apertures that coupled the received light into pre-amplified single-mode fiber detectors. Similar equipment was used in a second experiment performed in the fall of 2009, which demonstrated an error-free air-to-ground link at propagation ranges up to 60 km. In both of these tests power levels at all fiber outputs were sampled at 1 msec intervals, which enabled a high-rate characterization of the received signal fluctuations. The database developed from these experiments encompasses a wide range of propagation geometries and turbulence conditions. This information has subsequently been analyzed in an attempt to correlate estimates of the turbulence profile with measurements of the scintillation index, characteristic fading time constant, scintillation patch size, and the shape parameters of the statistical distributions of the received signals. Significant findings include observations of rapid changes in the scintillation index driven by solar flux variations, consistent similarities in the values of the alpha and beta shape parameters of the gamma-gamma distribution function, and strong evidence of channel reciprocity. This work was sponsored by the Department of Defense, RRCO DDR&E, under Air Force Contract FA8721-05-C-0002. Opinions, interpretations, conclusions and recommendations are those of the authors and are not necessarily endorsed by the United States Government.

  8. Consumer preferences for food labels on tomatoes in Germany - A comparison of a quasi-experiment and two stated preference approaches.

    PubMed

    Meyerding, Stephan G H

    2016-08-01

    In many studies, consumer preferences are determined by using direct surveys. For this method social desirability is problematic. This leads to the effect that participants answer in a way that they perceive as desired by society. This leads to the stated importance of certain features in these studies not being reflected in real purchasing decisions. Therefore, the aim of the study is to compare consumer preferences measured by a quasi-experiment to those quantified by direct questions. Another objective is to quantify the part-worth utilities of product characteristics such as origin, price and food labels. Part-worth utilities are estimated on an interval scale with an arbitrary origin and are a measure for preferences. The real purchasing situation was simulated in a quasi-experiment using a choice-based conjoint analysis. The part-worth utilities were then compared with the results of a conventional preference assessment (Likert scale). For this purpose, 645 consumers from all over Germany were surveyed in 2014. The participants were on average 44 years old and 63% were women. The results of the conjoint analysis report the highest part-worth utility (2.853) for the lowest price (1.49€), followed by the characteristic "grown locally" (2.157). For the labels, the German organic label shows the highest part-worth utility (0.785) followed by Fairtrade/"A heart for the producer" (0.200). It is noticeable that the carbon footprint labels have negative part-worth utilities compared to tomatoes without a label (-0.130 with CO2 indication, -0.186 without CO2 indication). The price is ranked 12th in the importance of the characteristics of purchasing tomatoes in the survey with a Likert scale, whereas it is first in the evaluation of the quasi-experiment (conjoint analysis), which supports the assumption of a social desirability bias.

  9. Estimations of global warming potentials from computational chemistry calculations for CH(2)F(2) and other fluorinated methyl species verified by comparison to experiment.

    PubMed

    Blowers, Paul; Hollingshead, Kyle

    2009-05-21

    In this work, the global warming potential (GWP) of methylene fluoride (CH(2)F(2)), or HFC-32, is estimated through computational chemistry methods. We find our computational chemistry approach reproduces well all phenomena important for predicting global warming potentials. Geometries predicted using the B3LYP/6-311g** method were in good agreement with experiment, although some other computational methods performed slightly better. Frequencies needed for both partition function calculations in transition-state theory and infrared intensities needed for radiative forcing estimates agreed well with experiment compared to other computational methods. A modified CBS-RAD method used to obtain energies led to superior results to all other previous heat of reaction estimates and most barrier height calculations when the B3LYP/6-311g** optimized geometry was used as the base structure. Use of the small-curvature tunneling correction and a hindered rotor treatment where appropriate led to accurate reaction rate constants and radiative forcing estimates without requiring any experimental data. Atmospheric lifetimes from theory at 277 K were indistinguishable from experimental results, as were the final global warming potentials compared to experiment. This is the first time entirely computational methods have been applied to estimate a global warming potential for a chemical, and we have found the approach to be robust, inexpensive, and accurate compared to prior experimental results. This methodology was subsequently used to estimate GWPs for three additional species [methane (CH(4)); fluoromethane (CH(3)F), or HFC-41; and fluoroform (CHF(3)), or HFC-23], where estimations also compare favorably to experimental values.

  10. Impact of Dynamic Specimen Shape Evolution on the Atom Probe Tomography Results of Doped Epitaxial Oxide Multilayers: Comparison of Experiment and Simulation

    SciTech Connect

    Madaan, Nitesh; Bao, Jie; Nandasiri, Manjula I.; Xu, Zhijie; Thevuthasan, Suntharampillai; Devaraj, Arun

    2015-08-31

    The experimental atom probe tomography results from two different specimen orientations (top-down and side-ways) of a high oxygen ion conducting Samaria-doped-ceria/Scandia-stabilized-zirconia multilayer thin film solid oxide fuel cell electrolyte was correlated with level-set method based field evaporation simulations for the same specimen orientations. This experiment-theory correlation explains the dynamic specimen shape evolution and ion trajectory aberrations that can induce density artifacts in final reconstruction leading to inaccurate estimation of interfacial intermixing. This study highlights the need and importance of correlating experimental results with field evaporation simulations when using atom probe tomography for studying oxide heterostructure interfaces.

  11. An assessment of the long-term drift in SBUV total ozone data, based on comparison with the Dobson network. [Solar Backscatter UltraViolet experiment

    NASA Technical Reports Server (NTRS)

    Fleig, Albert J.; Bhartia, Pawan K.; Silberstein, David S.

    1986-01-01

    Six years of total ozone data derived from the Nimbus 7 Solar Backscatter Ultraviolet (SBUV) experiment are compared with results from 41 Dobson stations to determine year-to-year changes in addition to the monthly bias change for individual stations and for the network. The SBUV measurements are found to drift against the Dobson stations with a linear trend of .38 + or - .13 percent/yr. The cause of the drift could not be separated between residual uncorrected drift in the SBUV instrument, limited sensitivity of the SBUV to increases in tropospheric ozone, and the effect of local increases in pollution level on individual Dobson stations.

  12. Stratospheric aerosol and gas experiment II and ROCOZ-A ozone profiles at Natal, Brazil - A basis for comparison with other satellite instruments

    NASA Technical Reports Server (NTRS)

    Barnes, Robert A.; Mcmaster, Leonard R.; Chu, William P.; Mccormick, M. Patrick; Gelman, Melvyn E.

    1991-01-01

    Satellite measurements of ozone carried out during the Stratospheric Aerosol and Gas Experiment II (SAGE II) are compared with in situ measurements made by the ROCOZ-A and electrochemical concentration cell ozonesondes at Natal (Brazil) during the Southern Hemisphere autumn of 1985. It was found that the SAGE II values were higher than the ROCOZ-A values by 3.4 percent, with an average absolute difference of 3.8 percent. It is suggested that the differences between the ozone density and mixing ratio results are due to the auxiliary temperature and pressure values for the satellite and in situ instruments.

  13. Organic matter production response to CO2 increase in open subarctic plankton communities: Comparison of six microcosm experiments under iron-limited and -enriched bloom conditions

    NASA Astrophysics Data System (ADS)

    Yoshimura, Takeshi; Sugie, Koji; Endo, Hisashi; Suzuki, Koji; Nishioka, Jun; Ono, Tsuneo

    2014-12-01

    Increase in seawater pCO2 and the corresponding decrease in pH caused by the increasing atmospheric CO2 concentration (i.e., ocean acidification) may affect organic matter production by phytoplankton communities. Organic matter production forms the basis of marine food webs and plays a crucial role in oceanic CO2 uptake through the biological carbon pump, and hence will potentially affect future marine ecosystem dynamics. However, responses of organic matter production in open ocean plankton ecosystems to CO2 increase have not been fully examined. We conducted on-deck microcosm experiments using high nutrient, low chlorophyll (HNLC) waters in the western subarctic Pacific and oceanic Bering Sea basin in summer 2008 and 2009, respectively, to examine the impacts of elevated CO2 on particulate and dissolved organic matter (i.e., POM and DOM, respectively) production. Iron deficient natural plankton communities were incubated for 7-14 days under multiple CO2 levels with and without iron enrichments (hereafter +Fe and -Fe treatments, respectively). By combining with our previous experiments at two sites, we created a comprehensive dataset on responses of organic matter production to CO2 increase during macronutrient replete conditions in HNLC waters. Significant differences in net particulate organic carbon production among CO2 treatments were observed only in the -Fe treatments, whereas that in net dissolved organic carbon production were mainly observed in the +Fe treatments, suggesting that CO2 may affect different processes depending on the Fe nutritional status. However, impacts of CO2 were not consistent among experiments and were much smaller than the consistent positive effects of Fe enrichment. In contrast, no significant differences among the CO2 treatments were observed for organic carbon partitioning into POM and DOM, and carbon to nitrogen ratio of net produced POM. We conclude that CO2 does not play a primary role, but could have secondary effects on

  14. PTSD Symptom Increases in Iraq-Deployed Soldiers: Comparison with NonDeployed Soldiers and Associations with Baseline Symptoms, Deployment Experiences, and Postdeployment Stress

    DTIC Science & Technology

    2010-02-01

    proportion of deployed U.S. forces. Because of the potential fo r greater occupational disruption, less consistent opportunity for combat training...deployment experiences, an occupational context notable for continuity of miliury-rdevanr duties and organizational structure, amI a readily accessible...Tnuma,ic Stres., 21, 290- 300. lOomC)’, R., K"ng, H. K, Kulinsky,j .. Bal<cr. D. G .. V"" .. ling.J. J .. Alpern, R., .t aI. (2007). Men",] healt h of

  15. Pollutant dispersion in a large indoor space: Part 2 -Computational Fluid Dynamics (CFD) predictions and comparison with ascale model experiment for isothermal flow

    SciTech Connect

    Finlayson, Elizabeth U.; Gadgil, Ashok J.; Thatcher, Tracy L.; Sextro, Richard G.

    2002-10-01

    This paper reports on an investigation of the adequacy of Computational fluid dynamics (CFD), using a standard Reynolds Averaged Navier Stokes (RANS) model, for predicting dispersion of neutrally buoyant gas in a large indoor space. We used CFD to predict pollutant (dye) concentration profiles in a water filled scale model of an atrium with a continuous pollutant source. Predictions from the RANS formulation are comparable to an ensemble average of independent identical experiments. Model results were compared to pollutant concentration data in a horizontal plane from experiments in a scale model atrium. Predictions were made for steady-state (fully developed) and transient (developing) pollutant concentrations. Agreement between CFD predictions and ensemble averaged experimental measurements is quantified using the ratios of CFD-predicted and experimentally measured dye concentration at a large number of points in the measurement plane. Agreement is considered good if these ratios fall between 0.5 and 2.0 at all points in the plane. The standard k-epsilon two equation turbulence model obtains this level of agreement and predicts pollutant arrival time to the measurement plane within a few seconds. These results suggest that this modeling approach is adequate for predicting isothermal pollutant transport in a large room with simple geometry.

  16. Polarization-dependent force driving the Eg mode in bismuth under optical excitation: comparison of first-principles theory with ultra-fast x-ray experiments

    NASA Astrophysics Data System (ADS)

    Fahy, Stephen; Murray, Eamonn

    2015-03-01

    Using first principles electronic structure methods, we calculate the induced force on the Eg (zone centre transverse optical) phonon mode in bismuth immediately after absorption of a ultrafast pulse of polarized light. To compare the results with recent ultra-fast, time-resolved x-ray diffraction experiments, we include the decay of the force due to carrier scattering, as measured in optical Raman scattering experiments, and simulate the optical absorption process, depth-dependent atomic driving forces, and x-ray diffraction in the experimental geometry. We find excellent agreement between the theoretical predictions and the observed oscillations of the x-ray diffraction signal, indicating that first-principles theory of optical absorption is well suited to the calculation of initial atomic driving forces in photo-excited materials following ultrafast excitation. This work is supported by Science Foundation Ireland (Grant No. 12/IA/1601) and EU Commission under the Marie Curie Incoming International Fellowships (Grant No. PIIF-GA-2012-329695).

  17. Are very poor women more vulnerable to violence against women? Comparison of experiences of female beggars with homemakers in an urban slum settlement in Ibadan, Nigeria.

    PubMed

    Fawole, Olufunmilayo I; Asekun-Olarinmoye, Esther O; Osungbade, Kayode O

    2013-11-01

    This study compared the prevalence and nature of violence against women (VAW) experienced by 104 female beggars with those of 219 homemakers in Sabo, an urban migrant slum settlement in Ibadan, Nigeria. The lifetime experience of VAW was 66.3% (95%CI: 62.5-70.1) among the beggars and 54.8% (95%CI: 52.2-57.6) among the homemakers (p=.05), while six months preceding the survey was: 56.7% (95%CI: 55.2-58.2) and 21.9% (95%CI: 20.8.2-23.0) respectively p=.0001). Psychological violence was experienced by 34.7% and 20.8% (p=.05); physical violence by 31.9% and 16.7% (p=.02) and sexual by 20.3% and 0.8% (p=.0001) of the beggars and homemakers respectively. Beggars with higher knowledge levels (aOR 0.23; 95%CI 0.07-0.80) and with more egalitarian attitudes (aOR 0.38; 95%CI 0.12-0.91) were less likely to experience violence. Suggestions to end VAW included female education (27.8%) and economic empowerment (59.2%). There is need to protect beggars by increasing access to health information, schooling, vocational training and income generating activities.

  18. Monte Carlo transport model comparison with 1A GeV accelerated iron experiment: heavy-ion shielding evaluation of NASA space flight-crew foodstuff

    NASA Technical Reports Server (NTRS)

    Stephens, D. L. Jr; Townsend, L. W.; Miller, J.; Zeitlin, C.; Heilbronn, L.

    2002-01-01

    Deep-space manned flight as a reality depends on a viable solution to the radiation problem. Both acute and chronic radiation health threats are known to exist, with solar particle events as an example of the former and galactic cosmic rays (GCR) of the latter. In this experiment Iron ions of 1A GeV are used to simulate GCR and to determine the secondary radiation field created as the GCR-like particles interact with a thick target. A NASA prepared food pantry locker was subjected to the iron beam and the secondary fluence recorded. A modified version of the Monte Carlo heavy ion transport code developed by Zeitlin at LBNL is compared with experimental fluence. The foodstuff is modeled as mixed nuts as defined by the 71st edition of the Chemical Rubber Company (CRC) Handbook of Physics and Chemistry. The results indicate a good agreement between the experimental data and the model. The agreement between model and experiment is determined using a linear fit to ordered pairs of data. The intercept is forced to zero. The slope fit is 0.825 and the R2 value is 0.429 over the resolved fluence region. The removal of an outlier, Z=14, gives values of 0.888 and 0.705 for slope and R2 respectively. c2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

  19. Long repetition time experiments for measurement of concentrations in systems with chemical exchange and undergoing temporal variation-comparison of methods with and without correction for saturation

    NASA Astrophysics Data System (ADS)

    Galbán, Craig J.; Spencer, Richard G. S.

    2003-02-01

    The purpose of this paper is to compare two methods for quantifying metabolite concentrations using the one-pulse experiment for a sample undergoing chemical exchange and subject to an intervention or other temporal variation. The methods, LATR-C (Long Acquisition TR (interpulse delay); Corrected for partial saturation) and LATR-NC (Long Acquisition TR; Not Corrected), are compared in terms of signal-to-noise ratio, SNR, per unit time and quantitation errors. Parameters relevant to the isolated perfused rat heart are used as a specific application, although the results are general. We assume throughout that spin-lattice relaxation times, T1, do not change. For a given flip angle, θ, TR's are calculated which result in maximal SNR per unit time under 10%, 5%, and 1% constraints on quantitation errors. Additional simulations were performed to demonstrate explicitly the dependence of the quantitation errors on TR for a fixed θ. We find (i) if the allowed error is large, and when both metabolite concentrations and rate constants vary, LATR-C permits use of shorter TR, and hence yields greater SNR per unit time, than LATR-NC; (ii) for small allowed error, the two methods give similar TR's and SNR per unit time, so that the simpler LATR-NC experiment may be preferred; (iii) large values of θ result in similar constrained TR's and hence SNR per unit time for the two methods; (iv) the ratio of concentrations of metabolites with similar T1 exhibit similar errors for the two methods.

  20. A comparison between Nimbus 5 THIR and ITPR temperatures and derived winds with rawinsonde data obtained in the AVE 2 experiment

    NASA Technical Reports Server (NTRS)

    Arnold, J. E.; Scoggins, J. R.; Fuelberg, H. E.

    1976-01-01

    During the period of May 11 and 12, 1974, NASA conducted its second Atmospheric Variability Experiment (AVE II) over the eastern United States. In this time interval, two Nimbus 5 orbits crossed the AVE II area, providing a series of ITPR soundings as well as THIR data. Horizontal temperature mapping of the AVE II cloud field is examined using two grid print map scales. Implied cloud top heights are compared with maximum radar-echo top reports. In addition, shelter temperatures in areas of clear sky are compared with the surface temperatures as determined from 11.5 micrometer radiometer data of the THIR experiment. The ITPR sounding accuracy is evaluated using interpolated radiosonde temperatures at times nearly coincident with the ITPR soundings. It was found that mean differences between the two data sets were as small as 1.3 C near 500 mb and as large as 2.9 C near the tropopause. The differences between ITPR and radiosonde temperatures at constant pressure levels were sufficient to induce significant differences in the horizontal temperature gradient. Cross sections of geostrophic wind along the orbital tracks were developed using a thermal wind buildup based on the ITPR temperature data and the radiosonde temperature data. Differences between the radiosonde and ITPR geostrophic winds could be explained on the basis of differences in the ITPR and radiosonde temperature gradients.

  1. Comparison of very-low-frequency auroral hiss with precipitating low-energy electrons by the use of simultaneous data from two Ogo 4 experiments.

    NASA Technical Reports Server (NTRS)

    Hoffman, R. A.; Laaspere, T.

    1972-01-01

    Determination of the origin of auroral hiss by comparing the records of a vlf experiment (0.3 to 18 kHz) with simultaneous data obtained by an auroral-particle experiment having detectors for precipitating electrons at 0.7, 2.3, and 7.3 keV. It is found that, on the dayside of the earth, the occurrence of vlf hiss correlates well with precipitation events at 0.7 keV, but in general very poorly with activity in the higher-energy channels. Exact correlation between variations in vlf hiss intensity and in electron fluxes is rare even at 0.7 keV. In addition, vlf hiss tends to be observed over a somewhat larger spatial region than precipitating 0.7-keV electrons. It is concluded that, on the dayside, auroral hiss is generated by soft (E less than 1 keV) 'cusp region' electrons and that the lack of detailed correlation between the two phenomena is caused by propagation effects as the hiss travels downward and spreads from the generation region.

  2. Monte Carlo transport model comparison with 1A GeV accelerated iron experiment: heavy-ion shielding evaluation of NASA space flight-crew foodstuff

    NASA Astrophysics Data System (ADS)

    Stephens, D. L.; Townsend, L. W.; Miller, J.; Zeitlin, C.; Heilbronn, L.

    Deep-space manned flight as a reality depends on a viable solution to the radiation problem. Both acute and chronic radiation health threats are known to exist, with solar particle events as an example of the former and galactic cosmic rays (GCR) of the latter. In this experiment Iron ions of 1A GeV are used to simulate GCR and to determine the secondary radiation field created as the GCR-like particles interact with a thick target. A NASA prepared food pantry locker was subjected to the iron beam and the secondary fluence recorded. A modified version of the Monte Carlo heavy ion transport code developed by Zeitlin at LBNL is compared with experimental fluence. The foodstuff is modeled as mixed nuts as defined by the 71 st edition of the Chemical Rubber Company (CRC) Handbook of Physics and Chemistry. The results indicate a good agreement between the experimental data and the model. The agreement between model and experiment is determined using a linear fit to ordered pairs of data. The intercept is forced to zero. The slope fit is 0.825 and the R 2 value is 0.429 over the resolved fluence region. The removal of an outlier, Z=14, gives values of 0.888 and 0.705 for slope and R 2 respectively.

  3. Comparison of human serum and bovine serum albumins on oxidation dynamics induced by talaporfin sodium photosensitization reaction with albumin rich conditions: solution experiments

    NASA Astrophysics Data System (ADS)

    Kurotsu, Mariko; Nakamura, Tetsuya; Takahashi, Mei; Ogawa, Emiyu; Arai, Tsunenori

    2014-02-01

    In order to understand extracellular-photosensitization reaction (PR) using talaporfin sodium, we studied comparison of oxidation dynamics of albumin and talaporfin sodium in solution system by visible and ultraviolet absorption spectrum measurements. Almost all talaporfin sodium particles may be bound to albumin in interstitial fluid, and this binding would affect the oxidation dynamics during this PR. Bovine serum albumin (BSA) is commonly used in vitro study but its binding characteristics with talaporfin sodium are different from human serum albumin (HSA). PR was operated in a solution composed of 20 μg/ml talaporfin sodium and 1.3 mg/ml HSA or BSA to simulate myocardial extracellular PR condition. Laser radiation of 662 nm was irradiated to this solution with irradiance of 0.29 W/cm2. Absorption spectra of these solutions were measured during the PR. We estimated oxidized ratio by absorption difference around 240 nm before and after the PR. Talaporfin sodium was oxidized 100% with HSA and BSA by the PR of 100 J/cm2 in radiant exposure. On the other hand, HSA and BSA were oxidized 60% and 94%, respectively in this radiant exposure. Q-band absorption peak of talaporfin sodium with HSA was shifted to 1 nm longer wavelength increasing radiant exposure up to 100 J/cm2. This longer wavelength shift would mean binding ratio of non-oxidized talaporfin sodium to non-oxidized HSA was increased with increasing radiant exposure. Therefore it would be possible that PR with talaporfin sodium bound to HSA might present efficient PDT than PR bound to BSA.

  4. Relative humidity distribution from SAPHIR experiment on board Megha-Tropiques satellite mission: Comparison with global radiosonde and other satellite and reanalysis data sets

    NASA Astrophysics Data System (ADS)

    Venkat Ratnam, M.; Basha, Ghouse; Krishna Murthy, B. V.; Jayaraman, A.

    2013-09-01

    For better understanding the life cycle of the convective systems and their interactions with the environment, a joint Indo-French satellite mission named Megha-Tropiques has been launched in October 2011 in a low-inclination (20°) orbit. In the present study, we show the first results on the comparison of relative humidity (RH) obtained using a six-channel microwave sounder, covering from surface to 100 hPa, from one of the payloads SAPHIR (Sounder for Atmospheric Profiling of Humidity in the Inter-tropical Regions). The RH observations from SAPHIR illustrated the numerous scales of variability in the atmosphere both vertically and horizontally. As a part of its validation, we compare SAPHIR RH with simultaneous observations from a network of radiosondes distributed across the world (±30° latitude), other satellites (Atmospheric Infrared Sounder, Infrared Atmospheric Sounder Interferometer, Constellation Observation System for Meteorology Ionosphere and Climate (COSMIC)), and various reanalysis (National Center for Environmental Prediction (NCEP), European Center for Medium-Range Weather Forecasts reanalysis (ERA)-Interim, Modern-Era Retrospective Analysis for Research and Application (MERRA)) products. Being at a low inclination, SAPHIR is able to show better global coverage when compared to any other existing satellites in the tropical region where some important weather processes take place. A very good correlation is noticed with the RH obtained from a global radiosonde network particularly in the altitude range corresponding to 850-250 hPa, thus providing a valuable data set for investigating the convective processes. In the case of satellite data sets, SAPHIR RH is well comparable with COSMIC RH. Among the reanalysis products, NCEP shows less difference with SAPHIR followed by ERA-Interim, and the MERRA products show large differences in the middle and upper troposphere.

  5. Structural and spectroscopic (UV-Vis, IR, Raman, and NMR) characteristics of anisaldehydes that are flavoring food additives: A density functional study in comparison with experiments

    NASA Astrophysics Data System (ADS)

    Altun, Ahmet; Swesi, O. A. A.; Alhatab, B. S. S.

    2017-01-01

    The molecular structures, vibrational spectra (IR and Raman), electronic spectra (UV-Vis and DOS), and NMR spectra (13C and 1H) of p-anisaldehyde, m-anisaldehyde, and o-anisaldehyde have been studied by using the B3LYP density functional and the 6-311++G** basis set. While p-anisaldehyde has been found to contain two stable conformers at room temperature, m-anisaldehyde and o-anisaldehyde contain four stable conformers. In agreement with the calculated ground-state energetics and small transition barriers, the comparison of the experimental and calculated spectra of the anisaldehydes indicates equilibrium between all conformers at room temperature. However, the two conformers of o-anisaldehyde, in which the methoxy group lies out of the ring plane, are too rare at the equilibrium. The equilibrium conditions of the conformers of the anisaldehyde isomers have been shown readily accessible through UV-Vis and 13C NMR spectral studies but requiring very detailed vibrational analyses. The effect of the solvent has been found to red-shift the electronic absorption bands and to make the anisaldehydes more reactive and soft. Molecular electrostatic potential maps of the anisaldehydes show that their oxygen atoms are the sites for nucleophilic reactivity. Compared with the most sophisticated NBO method, ESP charges have been found mostly reliable while Mulliken charges fail badly with the present large 6-311++G** basis set. The present calculations reproduce not only the experimental spectral characteristics of the anisaldehydes but also reveal their several structural features.

  6. Comparisons between high-resolution profiles of squared refractive index gradient M2 measured by the Middle and Upper Atmosphere Radar and unmanned aerial vehicles (UAVs) during the Shigaraki UAV-Radar Experiment 2015 campaign

    NASA Astrophysics Data System (ADS)

    Luce, Hubert; Kantha, Lakshmi; Hashiguchi, Hiroyuki; Lawrence, Dale; Yabuki, Masanori; Tsuda, Toshitaka; Mixa, Tyler

    2017-03-01

    New comparisons between the square of the generalized potential refractive index gradient M2, estimated from the very high-frequency (VHF) Middle and Upper Atmosphere (MU) Radar, located at Shigaraki, Japan, and unmanned aerial vehicle (UAV) measurements are presented. These comparisons were performed at unprecedented temporal and range resolutions (1-4 min and ˜ 20 m, respectively) in the altitude range ˜ 1.27-4.5 km from simultaneous and nearly collocated measurements made during the ShUREX (Shigaraki UAV-Radar Experiment) 2015 campaign. Seven consecutive UAV flights made during daytime on 7 June 2015 were used for this purpose. The MU Radar was operated in range imaging mode for improving the range resolution at vertical incidence (typically a few tens of meters). The proportionality of the radar echo power to M2 is reported for the first time at such high time and range resolutions for stratified conditions for which Fresnel scatter or a reflection mechanism is expected. In more complex features obtained for a range of turbulent layers generated by shear instabilities or associated with convective cloud cells, M2 estimated from UAV data does not reproduce observed radar echo power profiles. Proposed interpretations of this discrepancy are presented.

  7. Comparison of surgical effect and postoperative patient experience between laparoendoscopic single-site and conventional laparoscopic varicocelectomy: a systematic review and meta-analysis

    PubMed Central

    Zhang, Zheng; Zheng, Shu-Juan; Yu, Wen; Han, You-Feng; Chen, Hai; Chen, Yun; Dai, Yu-Tian

    2017-01-01

    The present meta-analysis was conducted to compare the clinical effect and patient experience of laparoendoscopic single-site varicocelectomy (LESSV) and conventional laparoscopic varicocelectomy. The candidate studies were included after literature search of database Cochrane Library, PubMed, EMBASE, and MEDLINE. Related information on essential data and outcome measures was extracted from the eligible studies by two independent authors, and a meta-analysis was conducted using STATA 12.0 software. Subgroup analyses were conducted by study design (RCT and non-RCT). The odds ratio (OR) or standardized mean difference (SMD) and their 95% confidence intervals (95% CIs) were used to estimate the outcome measures. Seven articles were included in our meta-analysis. The results indicated that patient who had undergone LESSV had a shorter duration of back to work (overall: SMD = −1.454, 95% CI: −2.502–−0.405, P = 0.007; non-RCT: SMD = −2.906, 95% CI: −3.796–−2.017, P = 0.000; and RCT: SMD = −0.841, 95% CI: −1.393–−0.289, P = 0.003) and less pain experience at 3 h or 6 h (SMD = −0.447, 95% CI: −0.754–−0.139, P = 0.004), day 1 (SMD = −0.477, 95% CI: −0.905–−0.05, P = 0.029), and day 2 (SMD = −0.612, 95% CI: −1.099–−0.125, P = 0.014) postoperatively based on RCT studies. However, the meta-analyses based on operation time, clinical effect (improvement of semen quality and scrotal pain relief), and complications (hydrocele and recurrence) yielded nonsignificant results. In conclusion, LESSV had a rapid recovery and less pain experience over conventional laparoscopic varicocelectomy. However, there was no statistically significant difference between the two varicocelectomy techniques in terms of the clinical effect and the incidence of hydrocele and varicocele recurrence. More high-quality studies are warranted for a comprehensive conclusion. PMID:27212128

  8. Comparison of velocity distribution functions in an argon shock wave between experiments and Monte Carlo calculations for Lennard-Jones potential

    NASA Astrophysics Data System (ADS)

    Matsumoto, Hiroaki; Koura, Katsuhisa

    1991-12-01

    The velocity distribution functions (VDF's) in an argon normal shock wave at an upstream high Mach number 7.183 and low temperature 16 K are calculated using the null-collision direct-simulation Monte Carlo method for the Lennard-Jones (LJ) potential to compare with the experimental results of Holtz and Muntz (1983). The convolved VDF's for the LJ potential are in reasonable agreement with the measured data in early and late regions of the shock wave but significantly different in the middle region. This discrepancy cannot be explained by a possible uncertainty in the potential well depth. Moreover, the difference in the convolved VDF's between the LJ potential and the softest and hardest unrealistic molecular models with no attractive force, i.e., the Maxwell molecule and hard sphere, is much smaller than the discrepancy between the experiments and Monte Carlo calculations.

  9. Comparison of velocity distribution functions in an argon shock wave between experiments and Monte Carlo calculations for Lennard-Jones potential

    NASA Astrophysics Data System (ADS)

    Matsumoto, Hiroaki; Koura, Katsuhisa

    1991-12-01

    The velocity distribution functions (VDF's) in an argon normal shock wave at an upstream high Mach number 7.183 and low temperature 16 K are calculated using the null-collision direct-simulation Monte Carlo method for the Lennard-Jones (LJ) potential to compare with the experimental results of Holtz and Muntz [Phys. Fluids 26, 2425 (1983)]. The convolved VDF's for the LJ potential are in reasonable agreement with the measured data in early and late regions of the shock wave but significantly different in the middle region. This discrepancy cannot be explained by a possible uncertainty in the potential well depth. Moreover, the difference in the convolved VDF's between the LJ potential and the softest and hardest unrealistic molecular models with no attractive force, i.e., the Maxwell molecule and hard sphere, is much smaller than the discrepancy between the experiments and Monte Carlo calculations.

  10. Comparison of cytogenetic effects in bone marrow of mice after the flight on the biosatellite "BION-M1" and the ground-based radiobiological experiment

    NASA Astrophysics Data System (ADS)

    Dorozhkina, Olga; Vorozhtsova, Svetlana; Ivanov, Alexander

    2016-07-01

    During space flight, the astronauts are exposed to radiation exposure at low doses with low dose rates, so one of the actual areas of Radiobiology is research of action of ionizing radiation in low and ultra-low doses. Violation of the chromosome apparatus of living biosystems, ranging from viruses and bacteria to humans, is the most reliable evidence of exposure to ionizing radiation. In this regard, the study of cytogenetic damage in the cells of humans and animals is central to space radiobiology (Fedorenko B.S., 2006). In experiment "BION - M1" by anaphase method was determined level of chromosomal aberrations in bone marrow cells of tibia of mice. Flight duration biosatellite "BION - M1" (Sychev V.N. et al., 2014) was 30 days in Earth orbit. Euthanasia of experimental animals was carried out after 12 hours from the moment of landing satellite by method of cervical dislocation. The level of chromosomal aberrations in vivarium-housed control mice was 1,75 ± 0,6% and 1,8 ± 0,45%, while the mitotic index 1,46 ± 0,09% and 1,53 ± 0,05%. The content of animals in the experiment with onboard equipment led to some increase in aberrant mitosis (2,3 ± 0,4%) and reduction of the mitotic index (1,37 ± 0,02%). In the flight experiment "BION-M1" was a statistically significant increase in level of chromosome aberrations (29,7 ± 4,18%) and a decrease in the mitotic index (0,74 ± 0,07%). According to VA Shurshakova (2014), the radiation dose to mice ranged from 32 to 72 mGy and relate to a range of small doses (ICRP, 2012). In this connection we conducted a series of experiments in the ground conditions, the aim of which was the study of earliest effects of ionizing radiation in vivo in mice irradiated with low doses of γ-irradiation of 10 to 200 mGy in the first 24 hours after exposure, i.e. within the first post-radiation exposure cell cycle. Studies were carried out on adult female mice outbred ICR (CD-1) - SPF category at the age of 4-4.5 months with an average

  11. Understanding unemployed people's job search behaviour, unemployment experience and well-being: a comparison of expectancy-value theory and self-determination theory.

    PubMed

    Vansteenkiste, Maarten; Lens, Willy; De Witte, Hans; Feather, N T

    2005-06-01

    Previous unemployment research has directly tested hypotheses derived from expectancy-value theory (EVT; Feather, 1982, 1990), but no comparative analysis has been executed with another motivational framework. In one large study with 446 unemployed people, separate analyses provided good evidence for predictions derived from both EVT and self-determination theory (SDT; Deci & Ryan, 1985, 2000). Comparative analyses indicated that the type of people's job search motivation, as conceptualized through the notions of autonomous versus controlled motivation within SDT, is an important predictor of people's unemployment experience and wellbeing, beyond people's strength of motivation assessed within EVT through expectancies of finding a job and employment value. The importance of simultaneously testing two theoretical frameworks is discussed.

  12. Quantum calculations of the IR spectrum of liquid water using ab initio and model potential and dipole moment surfaces and comparison with experiment.

    PubMed

    Liu, Hanchao; Wang, Yimin; Bowman, Joel M

    2015-05-21

    The calculation and characterization of the IR spectrum of liquid water have remained a challenge for theory. In this paper, we address this challenge using a combination of ab initio approaches, namely, a quantum treatment of IR spectrum using the ab initio WHBB water potential energy surface and a refined ab initio dipole moment surface. The quantum treatment is based on the embedded local monomer method, in which the three intramolecular modes of each embedded H2O monomer are fully coupled and also coupled singly to each of six intermolecular modes. The new dipole moment surface consists of a previous spectroscopically accurate 1-body dipole moment surface and a newly fitted ab initio intrinsic 2-body dipole moment. A detailed analysis of the new dipole moment surface in terms of the coordinate dependence of the effective atomic charges is done along with tests of it for the water dimer and prism hexamer double-harmonic spectra against direct ab initio calculations. The liquid configurations are taken from previous molecular dynamics calculations of Skinner and co-workers, using the TIP4P plus E3B rigid monomer water potential. The IR spectrum of water at 300 K in the range of 0-4000 cm(-1) is calculated and compared with experiment, using the ab initio WHBB potential and new ab initio dipole moment, the q-TIP4P/F potential, which has a fixed-charged description of the dipole moment, and the TTM3-F potential and dipole moment surfaces. The newly calculated ab initio spectrum is in very good agreement with experiment throughout the above spectral range, both in band positions and intensities. This contrasts to results with the other potentials and dipole moments, especially the fixed-charge q-TIP4P/F model, which gives unrealistic intensities. The calculated ab initio spectrum is analyzed by examining the contribution of various transitions to each band.

  13. Examination of important life experiences of the oldest-old: cross-cultural comparisons of U.S. and Japanese centenarians.

    PubMed

    da Rosa, Grace; Martin, Peter; Gondo, Yasuyuki; Hirose, Nobuyoshi; Ishioka, Yoshiko; Poon, Leonard W

    2014-06-01

    The purpose of this study was to compare the most important life events reported by U.S. and Japanese centenarians. This study included a population-based sample of 239 U.S. centenarians from the Georgia Centenarian Study and 304 Japanese centenarians from the Tokyo Centenarian Study. Two open-ended life events questions were categorized and grouped into different life event domains. Several cross-tabulations were computed to investigate culture and gender differences in most important life event domains. Next, four configural frequency analyses were conducted using Neuroticism, Extraversion, and the first most often mentioned life event domain for each sample (i.e., marriage and historical life events). Results suggest that events related to marriage were the most frequent important event domains mentioned by U.S. centenarians. The Japanese sample was more likely to report historical events. Men from the U.S. were more likely to report events related to work and retirement compared to U.S. women, and U.S. women reported events related to family as the most important life events when compared to U.S. men. Japanese women considered events related to marriage, death and grief as the most important life events when compared to Japanese men. In addition, Japanese men reported events related to work and retirement as the most important life events. A cross-cultural difference was found in life events: U.S. centenarians were more likely to mention positive experiences related to marriage and children, whereas Japanese centenarians reported mostly negative and traumatic experiences such as historical, death/grief, and work/retirement events.

  14. Coarse-grained models for fluids and their mixtures: Comparison of Monte Carlo studies of their phase behavior with perturbation theory and experiment

    NASA Astrophysics Data System (ADS)

    Mognetti, B. M.; Virnau, P.; Yelash, L.; Paul, W.; Binder, K.; Müller, M.; MacDowell, L. G.

    2009-01-01

    The prediction of the equation of state and the phase behavior of simple fluids (noble gases, carbon dioxide, benzene, methane, and short alkane chains) and their mixtures by Monte Carlo computer simulation and analytic approximations based on thermodynamic perturbation theory is discussed. Molecules are described by coarse grained models, where either the whole molecule (carbon dioxide, benzene, and methane) or a group of a few successive CH2 groups (in the case of alkanes) are lumped into an effective point particle. Interactions among these point particles are fitted by Lennard-Jones (LJ) potentials such that the vapor-liquid critical point of the fluid is reproduced in agreement with experiment; in the case of quadrupolar molecules a quadrupole-quadrupole interaction is included. These models are shown to provide a satisfactory description of the liquid-vapor phase diagram of these pure fluids. Investigations of mixtures, using the Lorentz-Berthelot (LB) combining rule, also produce satisfactory results if compared with experiment, while in some previous attempts (in which polar solvents were modeled without explicitly taking into account quadrupolar interaction), strong violations of the LB rules were required. For this reason, the present investigation is a step towards predictive modeling of polar mixtures at low computational cost. In many cases Monte Carlo simulations of such models (employing the grand-canonical ensemble together with reweighting techniques, successive umbrella sampling, and finite size scaling) yield accurate results in very good agreement with experimental data. Simulation results are quantitatively compared to an analytical approximation for the equation of state of the same model, which is computationally much more efficient, and some systematic discrepancies are discussed. These very simple coarse-grained models of small molecules developed here should be useful, e.g., for simulations of polymer solutions with such molecules as

  15. Coarse-grained models for fluids and their mixtures: Comparison of Monte Carlo studies of their phase behavior with perturbation theory and experiment.

    PubMed

    Mognetti, B M; Virnau, P; Yelash, L; Paul, W; Binder, K; Müller, M; MacDowell, L G

    2009-01-28

    The prediction of the equation of state and the phase behavior of simple fluids (noble gases, carbon dioxide, benzene, methane, and short alkane chains) and their mixtures by Monte Carlo computer simulation and analytic approximations based on thermodynamic perturbation theory is discussed. Molecules are described by coarse grained models, where either the whole molecule (carbon dioxide, benzene, and methane) or a group of a few successive CH(2) groups (in the case of alkanes) are lumped into an effective point particle. Interactions among these point particles are fitted by Lennard-Jones (LJ) potentials such that the vapor-liquid critical point of the fluid is reproduced in agreement with experiment; in the case of quadrupolar molecules a quadrupole-quadrupole interaction is included. These models are shown to provide a satisfactory description of the liquid-vapor phase diagram of these pure fluids. Investigations of mixtures, using the Lorentz-Berthelot (LB) combining rule, also produce satisfactory results if compared with experiment, while in some previous attempts (in which polar solvents were modeled without explicitly taking into account quadrupolar interaction), strong violations of the LB rules were required. For this reason, the present investigation is a step towards predictive modeling of polar mixtures at low computational cost. In many cases Monte Carlo simulations of such models (employing the grand-canonical ensemble together with reweighting techniques, successive umbrella sampling, and finite size scaling) yield accurate results in very good agreement with experimental data. Simulation results are quantitatively compared to an analytical approximation for the equation of state of the same model, which is computationally much more efficient, and some systematic discrepancies are discussed. These very simple coarse-grained models of small molecules developed here should be useful, e.g., for simulations of polymer solutions with such molecules as

  16. Chemical dynamics simulations of the monohydrated OH(-)(H2O) + CH3I reaction. Atomic-level mechanisms and comparison with experiment.

    PubMed

    Xie, Jing; Otto, Rico; Wester, Roland; Hase, William L

    2015-06-28

    Direct dynamics simulations, with B97-1/ECP/d theory, were performed to study the role of microsolvation for the OH(-)(H2O) + CH3I reaction. The SN2 reaction dominates at all reactant collision energies, but at higher collision energies proton transfer to form CH2I(-), and to a lesser extent CH2I(-) (H2O), becomes important. The SN2 reaction occurs by direct rebound and stripping mechanisms, and 28 different indirect atomistic mechanisms, with the latter dominating. Important components of the indirect mechanisms are the roundabout and formation of SN2 and proton transfer pre-reaction complexes and intermediates, including [CH3--I--OH](-). In contrast, for the unsolvated OH(-) + CH3I SN2 reaction, there are only seven indirect atomistic mechanisms and the direct mechanisms dominate. Overall, the simulation results for the OH(-)(H2O) + CH3I SN2 reaction are in good agreement with experiment with respect to reaction rate constant, product branching ratio, etc. Differences between simulation and experiment are present for the SN2 velocity scattering angle at high collision energies and the proton transfer probability at low collision energies. Equilibrium solvation by the H2O molecule is unimportant. The SN2 reaction is dominated by events in which H2O leaves the reactive system as CH3OH is formed or before CH3OH formation. Formation of solvated products is unimportant and participation of the (H2O)CH3OH---I(-) post-reaction complex for the SN2 reaction is negligible.

  17. Quantum calculations of the IR spectrum of liquid water using ab initio and model potential and dipole moment surfaces and comparison with experiment

    SciTech Connect

    Liu, Hanchao; Wang, Yimin; Bowman, Joel M.

    2015-05-21

    The calculation and characterization of the IR spectrum of liquid water have remained a challenge for theory. In this paper, we address this challenge using a combination of ab initio approaches, namely, a quantum treatment of IR spectrum using the ab initio WHBB water potential energy surface and a refined ab initio dipole moment surface. The quantum treatment is based on the embedded local monomer method, in which the three intramolecular modes of each embedded H{sub 2}O monomer are fully coupled and also coupled singly to each of six intermolecular modes. The new dipole moment surface consists of a previous spectroscopically accurate 1-body dipole moment surface and a newly fitted ab initio intrinsic 2-body dipole moment. A detailed analysis of the new dipole moment surface in terms of the coordinate dependence of the effective atomic charges is done along with tests of it for the water dimer and prism hexamer double-harmonic spectra against direct ab initio calculations. The liquid configurations are taken from previous molecular dynamics calculations of Skinner and co-workers, using the TIP4P plus E3B rigid monomer water potential. The IR spectrum of water at 300 K in the range of 0–4000 cm{sup −1} is calculated and compared with experiment, using the ab initio WHBB potential and new ab initio dipole moment, the q-TIP4P/F potential, which has a fixed-charged description of the dipole moment, and the TTM3-F potential and dipole moment surfaces. The newly calculated ab initio spectrum is in very good agreement with experiment throughout the above spectral range, both in band positions and intensities. This contrasts to results with the other potentials and dipole moments, especially the fixed-charge q-TIP4P/F model, which gives unrealistic intensities. The calculated ab initio spectrum is analyzed by examining the contribution of various transitions to each band.

  18. Chemical dynamics simulations of the monohydrated OH-(H2O) + CH3I reaction. Atomic-level mechanisms and comparison with experiment

    NASA Astrophysics Data System (ADS)

    Xie, Jing; Otto, Rico; Wester, Roland; Hase, William L.

    2015-06-01

    Direct dynamics simulations, with B97-1/ECP/d theory, were performed to study the role of microsolvation for the OH-(H2O) + CH3I reaction. The SN2 reaction dominates at all reactant collision energies, but at higher collision energies proton transfer to form CH2I-, and to a lesser extent CH2I- (H2O), becomes important. The SN2 reaction occurs by direct rebound and stripping mechanisms, and 28 different indirect atomistic mechanisms, with the latter dominating. Important components of the indirect mechanisms are the roundabout and formation of SN2 and proton transfer pre-reaction complexes and intermediates, including [CH3--I--OH]-. In contrast, for the unsolvated OH- + CH3I SN2 reaction, there are only seven indirect atomistic mechanisms and the direct mechanisms dominate. Overall, the simulation results for the OH-(H2O) + CH3IߙSN2 reaction are in good agreement with experiment with respect to reaction rate constant, product branching ratio, etc. Differences between simulation and experiment are present for the SN2 velocity scattering angle at high collision energies and the proton transfer probability at low collision energies. Equilibrium solvation by the H2O molecule is unimportant. The SN2 reaction is dominated by events in which H2O leaves the reactive system as CH3OH is formed or before CH3OH formation. Formation of solvated products is unimportant and participation of the (H2O)CH3OH---I- post-reaction complex for the SN2 reaction is negligible.

  19. Quantum calculations of the IR spectrum of liquid water using ab initio and model potential and dipole moment surfaces and comparison with experiment

    NASA Astrophysics Data System (ADS)

    Liu, Hanchao; Wang, Yimin; Bowman, Joel M.

    2015-05-01

    The calculation and characterization of the IR spectrum of liquid water have remained a challenge for theory. In this paper, we address this challenge using a combination of ab initio approaches, namely, a quantum treatment of IR spectrum using the ab initio WHBB water potential energy surface and a refined ab initio dipole moment surface. The quantum treatment is based on the embedded local monomer method, in which the three intramolecular modes of each embedded H2O monomer are fully coupled and also coupled singly to each of six intermolecular modes. The new dipole moment surface consists of a previous spectroscopically accurate 1-body dipole moment surface and a newly fitted ab initio intrinsic 2-body dipole moment. A detailed analysis of the new dipole moment surface in terms of the coordinate dependence of the effective atomic charges is done along with tests of it for the water dimer and prism hexamer double-harmonic spectra against direct ab initio calculations. The liquid configurations are taken from previous molecular dynamics calculations of Skinner and co-workers, using the TIP4P plus E3B rigid monomer water potential. The IR spectrum of water at 300 K in the range of 0-4000 cm-1 is calculated and compared with experiment, using the ab initio WHBB potential and new ab initio dipole moment, the q-TIP4P/F potential, which has a fixed-charged description of the dipole moment, and the TTM3-F potential and dipole moment surfaces. The newly calculated ab initio spectrum is in very good agreement with experiment throughout the above spectral range, both in band positions and intensities. This contrasts to results with the other potentials and dipole moments, especially the fixed-charge q-TIP4P/F model, which gives unrealistic intensities. The calculated ab initio spectrum is analyzed by examining the contribution of various transitions to each band.

  20. A comparison of two methods for prediction of response and rates of inbreeding in selected populations with the results obtained in two selection experiments

    PubMed Central

    Loywyck, Valérie; Bijma, Piter; Laan, Marie-Hélène Pinard-van der; van Arendonk, Johan; Verrier, Etienne

    2005-01-01

    Selection programmes are mainly concerned with increasing genetic gain. However, short-term progress should not be obtained at the expense of the within-population genetic variability. Different prediction models for the evolution within a small population of the genetic mean of a selected trait, its genetic variance and its inbreeding have been developed but have mainly been validated through Monte Carlo simulation studies. The purpose of this study was to compare theoretical predictions to experimental results. Two deterministic methods were considered, both grounded on a polygenic additive model. Differences between theoretical predictions and experimental results arise from differences between the true and the assumed genetic model, and from mathematical simplifications applied in the prediction methods. Two sets of experimental lines of chickens were used in this study: the Dutch lines undergoing true truncation mass selection, the other lines (French) undergoing mass selection with a restriction on the representation of the different families. This study confirmed, on an experimental basis, that modelling is an efficient approach to make useful predictions of the evolution of selected populations although the basic assumptions considered in the models (polygenic additive model, normality of the distribution, base population at the equilibrium, etc.) are not met in reality. The two deterministic methods compared yielded results that were close to those observed in real data, especially when the selection scheme followed the rules of strict mass selection: for instance, both predictions overestimated the genetic gain in the French experiment, whereas both predictions were close to the observed values in the Dutch experiment. PMID:15823236

  1. Reactions to First Postpubertal Male Same-Sex Sexual Experience in the Kinsey Sample: A Comparison of Minors With Peers, Minors With Adults, and Adults With Adults.

    PubMed

    Rind, Bruce; Welter, Max

    2016-10-01

    Rind and Welter (2014) examined first postpubertal coitus using the Kinsey sample, finding that reactions were just as positive, and no more negative, among minors with adults compared to minors with peers and adults with adults. In the present study, we examined first postpubertal male same-sex sexual experiences in the Kinsey same-sex sample (i.e., participants mostly with extensive postpubertal same-sex behavior), comparing reactions across the same age categories. These data were collected between 1938 and 1961 (M year: 1946). Minors under age 18 years with adults (M ages: 14.0 and 30.5, respectively) reacted positively (i.e., enjoyed the experience "much") often (70 %) and emotionally negatively (e.g., fear, disgust, shame, regret) infrequently (16 %). These rates were the same as adults with adults (M ages: 21.2 and 25.9, respectively): 68 and 16 %, respectively. Minors with peers (M ages: 13.3 and 13.8, respectively) reacted positively significantly more often (82 %) and negatively nominally less often (9 %). Minors with adults reacted positively to intercourse (oral, anal) just as often (69 %) as to outercourse (body contact, masturbation, femoral) (72 %) and reacted emotionally negatively significantly less often (9 vs. 25 %, respectively). For younger minors (≤14) with adults aged 5-19 years older, reactions were just as positive (83 %) as for minors with peers within 1 year of age (84 %) and no more emotionally negative (11 vs. 7 %, respectively). Results are discussed in relation to findings regarding first coitus in the Kinsey sample and to the cultural context particular to Kinsey's time.

  2. Transition from multiple port to single port video-assisted thoracoscopic anatomic pulmonary resection: early experience and comparison of perioperative outcomes

    PubMed Central

    French, Daniel G.; Thompson, Calvin

    2016-01-01

    Background Single port thoracoscopy is an approach aimed at minimizing trauma to the chest wall during lung resection. The objectives of this study were to describe early experience in the transition from multiple port video-assisted thoracic surgery (VATS) to single port surgery (S-VATS) and to compare perioperative outcomes between approaches. Methods Consecutive anatomic lung resections using S-VATS were reviewed and compared to a historical, prospective cohort of multiple port VATS cases. Outcomes analysis was focused on the use of operating room resources and postoperative recovery. Results Over 12 months, 50 S-VATS procedures were completed by one surgeon and compared to an equal number of VATS patients. The groups were similar in age, gender, BMI, comorbidity, tumor size and pulmonary function. There was no statistically significant difference in operative time. All tumors were completely resected (R0) and the median number of lymph nodes evaluated pathologically was equivalent {S-VATS=7 [4-10]; VATS=7 [4-10]; P=0.92}. There was no significant difference in conversion rate {S-VATS=2 (4%); VATS=1 (2%); P=0.56}. The median length of stay was similar in both groups {S-VATS=4 [3-7]; VATS=4 [3-7]; P=0.99}. There was no mortality and no significant difference in the rate of major complications {S-VATS=10/50 [20%]; VATS=5/50 [10%]; P=0.26}. There was no difference in patient reported pain as measured by a visual analog scale at 24 hours {S-VATS=4 [2-5]; VATS=4 [3-5]; P=0.63}. Conclusions Early experience in the transition from multiple port VATS to S-VATS lung resection indicates that safety, efficiency and surgical quality are preserved. More long-term data are required. Alternative approaches to perform thoracoscopic lung resection should be carefully evaluated and compared to established minimally invasive techniques. PMID:27134834

  3. Hydraulic evolution of high-density turbidity currents from the Brushy Canyon Formation, Eddy County, New Mexico inferred by comparison to settling and sorting experiments

    NASA Astrophysics Data System (ADS)

    Motanated, Kannipa; Tice, Michael M.

    2016-05-01

    Hydraulic transformations in turbidity currents are commonly driven by or reflected in changes in suspended sediment concentrations, but changes preceding transformations can be difficult to diagnose because they do not produce qualitative changes in resultant deposits. This study integrates particle settling experiments and in situ detection of hydraulically contrasting particles in turbidites in order to infer changes in suspended sediment concentration during deposition of massive (Bouma Ta) sandstone divisions. Because grains of contrasting density are differentially sorted during hindered settling from dense suspensions, relative grading patterns can be used to estimate suspended sediment concentrations and interpret hydraulic evolution of the depositing turbidity currents. Differential settling of dense particles (aluminum ballotini) through suspensions of hydraulically coarser light particles (silica ballotini) with volumetric concentration, Cv, were studied in a thin vessel by using particle-image-velocimetry. At high Cv, aluminum particles were less retarded than co-sedimenting silica particles, and effectively settled as hydraulically coarser grains. This was because particles were entrained into clusters dominated by the settling behavior of the silica particles. Terminal settling velocities of both particles converged at Cv ≥ 25%, and particle sorting was diminished. The results of settling experiments were applied to understand settling of analogous feldspar and zircon grains in natural turbidity flows. Distributions of light and heavy mineral grains in massive sandstones, Bouma Ta divisions, of turbidites from the Middle Permian Brushy Canyon Formation were observed in situ by X-ray fluorescence microscopy (μXRF). Hydraulic sorting of these grains resulted in characteristic patterns of zirconium abundance that decreased from base to top within Ta divisions. These profiles resulted from upward fining of zircon grains with respect to co

  4. MO-E-17A-03: Monte Carlo CT Dose Calculation: A Comparison Between Experiment and Simulation Using ARCHER-CT

    SciTech Connect

    Liu, T; Du, X; Su, L; Gao, Y; Ji, W; Xu, X; Zhang, D; Shi, J; Liu, B; Kalra, M

    2014-06-15

    Purpose: To compare the CT doses derived from the experiments and GPU-based Monte Carlo (MC) simulations, using a human cadaver and ATOM phantom. Methods: The cadaver of an 88-year old male and the ATOM phantom were scanned by a GE LightSpeed Pro 16 MDCT. For the cadaver study, the Thimble chambers (Model 10×5−0.6CT and 10×6−0.6CT) were used to measure the absorbed dose in different deep and superficial organs. Whole-body scans were first performed to construct a complete image database for MC simulations. Abdomen/pelvis helical scans were then conducted using 120/100 kVps, 300 mAs and a pitch factor of 1.375:1. For the ATOM phantom study, the OSL dosimeters were used and helical scans were performed using 120 kVp and x, y, z tube current modulation (TCM). For the MC simulations, sufficient particles were run in both cases such that the statistical errors of the results by ARCHER-CT were limited to 1%. Results: For the human cadaver scan, the doses to the stomach, liver, colon, left kidney, pancreas and urinary bladder were compared. The difference between experiments and simulations was within 19% for the 120 kVp and 25% for the 100 kVp. For the ATOM phantom scan, the doses to the lung, thyroid, esophagus, heart, stomach, liver, spleen, kidneys and thymus were compared. The difference was 39.2% for the esophagus, and within 16% for all other organs. Conclusion: In this study the experimental and simulated CT doses were compared. Their difference is primarily attributed to the systematic errors of the MC simulations, including the accuracy of the bowtie filter modeling, and the algorithm to generate voxelized phantom from DICOM images. The experimental error is considered small and may arise from the dosimeters. R01 grant (R01EB015478) from National Institute of Biomedical Imaging and Bioengineering.

  5. Multi-Layer Arctic Mixed-Phase Clouds Simulated by a Cloud-Resolving Model: Comparison with ARM Observations and Sensitivity Experiments

    NASA Technical Reports Server (NTRS)

    Luo, Yali; Xu, Kuan-Man; Morrison, Hugh; McFarquhar, Greg M.; Wang, Zhien; Zhang, Gong

    2007-01-01

    A cloud-resolving model (CRM) is used to simulate the multiple-layer mixed-phase stratiform (MPS) clouds that occurred during a three-and-a-half day subperiod of the Department of Energy-Atmospheric Radiation Measurement Program s Mixed-Phase Arctic Cloud Experiment (M-PACE). The CRM is implemented with an advanced two-moment microphysics scheme, a state-of-the-art radiative transfer scheme, and a complicated third-order turbulence closure. Concurrent meteorological, aerosol, and ice nucleus measurements are used to initialize the CRM. The CRM is prescribed by time-varying large-scale advective tendencies of temperature and moisture and surface turbulent fluxes of sensible and latent heat. The CRM reproduces the occurrences of the single- and double-layer MPS clouds as revealed by the M-PACE observations. However, the simulated first cloud layer is lower and the second cloud layer thicker compared to observations. The magnitude of the simulated liquid water path agrees with that observed, but its temporal variation is more pronounced than that observed. As in an earlier study of single-layer cloud, the CRM also captures the major characteristics in the vertical distributions and temporal variations of liquid water content (LWC), total ice water content (IWC), droplet number concentration and ice crystal number concentration (nis) as suggested by the aircraft observations. However, the simulated mean values differ significantly from the observed. The magnitude of nis is especially underestimated by one order of magnitude. Sensitivity experiments suggest that the lower cloud layer is closely related to the surface fluxes of sensible and latent heat; the upper cloud layer is probably initialized by the large-scale advective cooling/moistening and maintained through the strong longwave (LW) radiative cooling near the cloud top which enhances the dynamical circulation; artificially turning off all ice-phase microphysical processes results in an increase in LWP by a

  6. Searching for resonances in the reaction Cl+CH4-->HCl+CH3: quantum versus quasiclassical dynamics and comparison with experiments.

    PubMed

    Martínez, Rodrigo; González, Miguel; Defazio, Paolo; Petrongolo, Carlo

    2007-09-14

    A quantum-mechanical (QM) and quasiclassical trajectory (QCT) study was performed on the title reaction, using a pseudotriatomic ab initio based surface. Probabilities and integral cross sections present some clear peaks versus the collision energy E(col), which we assign to Feshbach resonances of the transition state, where the light H atom oscillates between the heavy Cl and CH(3) groups. For ground-state reactants, reactivity is essentially of quantum origin (QCT observables and oscillations are smaller, or much smaller, than QM ones), and the calculated integral cross section and product distributions are in reasonable agreement with the experiment. The reaction occurs through an abstraction mechanism, following both a direct and an indirect mechanism. The quasiclassical trajectory calculations show the participation of a short-lived collision complex in the microscopic reaction mechanism. Finally, QCT differential cross sections of Cl+CH(4)-->HCl (nu(')=0 and 1)+CH(3) oscillate versus E(col), whereas experimentally this only occurs for HCl (nu(')=1). This theoretical result and other oscillating properties found here could, however, be related to the existence of a Feshbach resonance for the production of HCl (nu(')=1), as suggested by experimentalists.

  7. Feature scale model of Si etching in SF{sub 6}/O{sub 2}/HBr plasma and comparison with experiments

    SciTech Connect

    Belen, Rodolfo Jun; Gomez, Sergi; Kiehlbauch, Mark; Aydil, Eray S.

    2006-03-15

    We have developed a semiempirical feature scale model of Si etching in SF{sub 6}/O{sub 2}/HBr plasma. Surface kinetics are modeled using parameters that describe F-based Si etching in SF{sub 6} and SF{sub 6}/O{sub 2} plasmas and Br-based Si etching in HBr plasma. The kinetic parameters in the model are constrained by matching simulated feature profiles with those experimentally obtained at various feed gas compositions. Excellent agreement between experiments and simulations is obtained. The combined experimental and profile simulation study reveals that the addition of HBr to SF{sub 6}/O{sub 2} plasmas results in improved sidewall passivation and elimination of the mask undercut. The vertical etch rate increases as a result of F and Br fluxes focusing toward the bottom of the feature by reflections from passivated sidewalls. Addition of SF{sub 6} to HBr discharge increases the etch rate through chemical etching that produces volatile SiBr{sub 4-x}F{sub x} etch products and ion-enhanced chemical sputtering of fluorinated and brominated Si surfaces by F-containing ions.

  8. Investigation of the validity of BEM for simulation of wind turbines in complex load cases and comparison with experiment and CFD

    NASA Astrophysics Data System (ADS)

    Rahimi, H.; Dose, B.; Stoevesandt, B.; Peinke, J.

    2016-09-01

    The aim of this work is to investigate the validity of simulation codes based on the Blade Element Momentum (BEM) theory for three important design load conditions. This paper includes the cases of yawed inflow, rotor tower interaction for downwind turbines and the standstill case. Computational Fluid Dynamics (CFD) and experimental data (when available) are used for the evaluation of the obtained results. For the yawed inflow, the results indicate that significant deviations between BEM and experiments & CFD can be observed. This discrepancy is caused by unsteady phenomena such as the advancing & retreating blade effect and the skewed wake effect. In the case of the rotor and tower interaction of the downwind turbine, the results show that the BEM based code overpredicts the sectional forces in terms of the normal and tangential forces by 20%. In the case of standstill, the evaluation of the results based on tip deflections shows clear differences in the output of both numerical approaches. While the flapwise deflections show a reasonable agreement, the CFD-based coupled solver predicts much larger edgewise vibrations.

  9. Phytoremediation and microbial community structure of soil from a metal-contaminated military shooting range: comparisons of field and pot experiments.

    PubMed

    Kim, Sunghyun; Baek, Kyunghwa; Lee, Insook

    2010-01-01

    In this study, the heavy metal uptake ability of two plant species, barnyard grass and Indian mallow, and the effects of associated micro-communities on the rhizosphere of these plants were investigated in metal-contaminated sites. In addition, the effectiveness of phytoremediation using these plants was compared under field and pot conditions. To accomplish this analysis, phytoremediation of general military shooting range soil was conducted for 8 weeks under the two conditions. The results showed that metal uptake by plants and reductions in soil metal concentration were lower in the field than in pots. However, soil dehydrogenase activities and microbial diversity increased in response to phytoremediation in the field. Specifically, the soil dehydrogenase activities of barnyard grass in field soils were 3-fold higher than those of potted soils. Moreover, the denaturing gradient gel electrophoresis patterns revealed that groups formed according to plant species. Finally, the Shannon-Weaver diversity index and Simpson dominance index were higher in the rhizosphere of barnyard grass than in the rhizosphere of Indian mallow under field conditions. These results indicate that it is difficult to apply the results obtained from pot experiments to field conditions. These findings can be used to inform future studies conducted to determine if field sites are suitable for phytoremediation based on the results of pot studies.

  10. Development of numerical model to investigate the laser driven shock waves from aluminum target into ambient air at atmospheric pressure and its comparison with experiment

    NASA Astrophysics Data System (ADS)

    Shiva, S. Sai; Leela, Ch.; Chaturvedi, S.; Sijoy, C. D.; Kiran, P. Prem

    2017-01-01

    A one-dimensional, three-temperature (electron, ion and thermal radiation) numerical model was developed to study the laser induced shock wave (LISW) propagation from aluminum target in ambient air at atmospheric pressure. The hydrodynamic equations of mass, momentum and energy are solved by using an implicit scheme in Lagrangian form. The model considers the laser absorption to take place via inverse-bremsstrahlung due to electron-ion (e-i) process. The flux limited electron thermal energy transport due e-i and e-n thermal energy relaxation equations are solved implicitly. The experimental characterization of spatio-temporal evolution of the LISW in air generated by focusing a second harmonic (532 nm, 7ns) of Nd:YAG laser on to surface of Al is performed using shadowgraphy technique with a temporal resolution of 1.5 ns. The velocity of SW observed in the experiments over 0.2 µs-8 µs time scales was compared with the numerical results to understand the SW transition from planar to spherical evolution.

  11. Ensemble urban flood simulation in comparison with laboratory-scale experiments: Impact of interaction models for manhole, sewer pipe, and surface flow

    NASA Astrophysics Data System (ADS)

    Noh, Seong Jin; Lee, Seungsoo; An, Hyunuk; Kawaike, Kenji; Nakagawa, Hajime

    2016-11-01

    An urban flood is an integrated phenomenon that is affected by various uncertainty sources such as input forcing, model parameters, complex geometry, and exchanges of flow among different domains in surfaces and subsurfaces. Despite considerable advances in urban flood modeling techniques, limited knowledge is currently available with regard to the impact of dynamic interaction among different flow domains on urban floods. In this paper, an ensemble method for urban flood modeling is presented to consider the parameter uncertainty of interaction models among a manhole, a sewer pipe, and surface flow. Laboratory-scale experiments on urban flood and inundation are performed under various flow conditions to investigate the parameter uncertainty of interaction models. The results show that ensemble simulation using interaction models based on weir and orifice formulas reproduces experimental data with hig