WorldWideScience

Sample records for numerous illustrations capture

  1. Introduction to Numerical Computation - analysis and Matlab illustrations

    DEFF Research Database (Denmark)

    Elden, Lars; Wittmeyer-Koch, Linde; Nielsen, Hans Bruun

    In a modern programming environment like eg MATLAB it is possible by simple commands to perform advanced calculations on a personal computer. In order to use such a powerful tool efiiciently it is necessary to have an overview of available numerical methods and algorithms and to know about...... are illustrated by examples in MATLAB....

  2. Uncertainty relation and probability. Numerical illustration

    International Nuclear Information System (INIS)

    Fujikawa, Kazuo; Umetsu, Koichiro

    2011-01-01

    The uncertainty relation and the probability interpretation of quantum mechanics are intrinsically connected, as is evidenced by the evaluation of standard deviations. It is thus natural to ask if one can associate a very small uncertainty product of suitably sampled events with a very small probability. We have shown elsewhere that some examples of the evasion of the uncertainty relation noted in the past are in fact understood in this way. We here numerically illustrate that a very small uncertainty product is realized if one performs a suitable sampling of measured data that occur with a very small probability. We introduce a notion of cyclic measurements. It is also shown that our analysis is consistent with the Landau-Pollak-type uncertainty relation. It is suggested that the present analysis may help reconcile the contradicting views about the 'standard quantum limit' in the detection of gravitational waves. (author)

  3. A Numerical and Experimental Study of Local Exhaust Capture Efficiency

    DEFF Research Database (Denmark)

    Madsen, U.; Breum, N. O.; Nielsen, Peter Vilhelm

    1993-01-01

    Direct capture efficiency of a local exhaust system is defined by introducing an imaginary control box surrounding the contaminant source and the exhaust opening. The imaginary box makes it possible to distinguish between contaminants directly captured and those that escape. Two methods for estim...... location is less important for the case studied. The choice of sampling strategy to obtain a representative background concentration is essential as substantial differences on direct capture efficiency are found. Recommendations are given......Direct capture efficiency of a local exhaust system is defined by introducing an imaginary control box surrounding the contaminant source and the exhaust opening. The imaginary box makes it possible to distinguish between contaminants directly captured and those that escape. Two methods...... for estimation of direct capture efficiency are given: (1) a numerical method based on the time-averaged Navier-Stokes equations for turbulent flows; and (2) a field method based on a representative background concentration. Direct capture efficiency is sensitive to the size of the control box, whereas its...

  4. Numerical simulation of two-phase flow with front-capturing

    International Nuclear Information System (INIS)

    Tzanos, C.P.; Weber, D.P.

    2000-01-01

    Because of the complexity of two-phase flow phenomena, two-phase flow codes rely heavily on empirical correlations. This approach has a number of serious shortcomings. Advances in parallel computing and continuing improvements in computer speed and memory have stimulated the development of numerical simulation tools that rely less on empirical correlations and more on fundamental physics. The objective of this work is to take advantage of developments in massively parallel computing, single-phase computational fluid dynamics of complex systems, and numerical methods for front capturing in two-phase flows to develop a computer code for direct numerical simulation of two-phase flow. This includes bubble/droplet transport, interface deformation and topology change, bubble-droplet interactions, interface mass, momentum, and energy transfer. In this work, the Navier-Stokes and energy equations are solved by treating both phases as a single fluid with interfaces between the two phases, and a discontinuity in material properties across the moving interfaces. The evolution of the interfaces is simulated by using the front capturing technique of the level-set methods. In these methods, the boundary of a two-fluid interface is modeled as the zero level set of a smooth function φ. The level-set function φ is defined as the signed distance from the interface (φ is negative inside a droplet/bubble and positive outside). Compared to other front-capturing or front-tracking methods, the level-set approach is relatively easy to implement even in three-dimensional flows, and it has been shown to simulate well the coalescence and breakup of droplets/bubbles

  5. Numerical study of particle capture efficiency in fibrous filter

    Directory of Open Access Journals (Sweden)

    Fan Jianhua

    2017-01-01

    Full Text Available Numerical simulations are performed for transport and deposition of particles over a fixed obstacle in a fluid flow. The effect of particle size and Stokes number on the particle capture efficiency is investigated using two methods. The first one is one-way coupling combining Lattice Boltzmann (LB method with Lagrangian point-like approach. The second one is two-way coupling based on the coupling between Lattice Boltzmann method and discrete element (DE method, which consider the particle influence on the fluid. Then the single fiber collection efficiency characterized by Stokes number (St are simulated by LB-DE methods. Results show that two-way coupling method is more appropriate in our case for particles larger than 8 μm. A good agreement has also been observed between our simulation results and existing correlations for single fiber collection efficiency. The numerical simulations presented in this work are useful to understand the particle transport and deposition and to predict the capture efficiency.

  6. Numerical prediction of CO2 capture process by a single droplet in alkaline spray

    International Nuclear Information System (INIS)

    Chen, Wei-Hsin; Tsai, Ming-Hang; Hung, Chen-I

    2013-01-01

    Highlights: • CO 2 capture by a single droplet is studied numerically. • Three different initial pH values of 10, 11, and 12 in the droplet are considered. • The initial pH value has a significant influence on the capture process. • The carbon capture rate is raised as the initial pH value rises. • The droplet with the initial pH value of 12 is feasible to perform CO 2 capture. - Abstract: Carbon dioxide captured by single droplets in sprays plays a fundamental role in reducing greenhouse gas emissions. This study focuses on CO 2 capture processes in single droplets in alkaline sprays using a numerical method. Three different initial pH values of 10, 11, and 12 in the droplet are considered. The capture behavior in the absence of chemical dissociation is also investigated for comparison. The predictions suggest that the chemical dissociation in the droplet substantially elongates the CO 2 capture process and the mass diffusion is the controlling mechanism of CO 2 capture process. For the chemical absorption, the final CO 2 capture amount by the droplet is mainly determined by HCO 3 - which is significantly influenced by the initial pH value. An increase in initial pH value raises the carbon capture amount by the droplet. The mean concentration of CO 3 2- is highly related to the variation of mean pH value, but its concentration is by far lower than those of H 2 O⋅CO 2 and HCO 3 - . Corresponding to the initial pH values of 10, 11, and 12, the times required for turning the basic droplet to the acidic one are in the orders of 10, 100, and 1000 ms. On account of larger carbon capture amount and shorter absorption period at a higher initial pH value, the carbon capture rate is lifted as the initial pH value rises, and CO 2 capture by droplets at the initial pH value of 12 is better than those at 10 and 11

  7. Numerical and theoretical aspects of the modelling of compressible two-phase flow by interface capture methods

    International Nuclear Information System (INIS)

    Kokh, S.

    2001-01-01

    This research thesis reports the development of a numerical direct simulation of compressible two-phase flows by using interface capturing methods. These techniques are based on the use of an Eulerian fixed grid to describe flow variables as well as the interface between fluids. The author first recalls conventional interface capturing methods and makes the distinction between those based on discontinuous colour functions and those based on level set functions. The approach is then extended to a five equation model to allow the largest as possible choice of state equations for the fluids. Three variants are developed. A solver inspired by the Roe scheme is developed for one of them. These interface capturing methods are then refined, more particularly for problems of numerical diffusion at the interface. A last part addresses the study of dynamic phase change. Non-conventional thermodynamics tools are used to study the structures of an interface which performs phase transition [fr

  8. Thermochemistry of a Biomimetic and Rubisco-Inspired CO2 Capture System from Air

    Directory of Open Access Journals (Sweden)

    Andrew Muelleman

    2016-07-01

    Full Text Available In theoretical studies of chemical reactions the reaction thermochemistry is usually reported for the stoichiometric reaction at standard conditions (ΔG°, ΔH°, ΔS°. We describe the computation of the equilibrium concentrations of the CO2-adducts for the general capture reaction CO2 + Capture System ⇆ CO2-adduct (GCR and the rubisco-type capture reaction CO2 + Capture System ⇆ CO2-adduct + H2O (RCR with consideration of the reaction CO2(g ⇆ CO2(aq via Henry’s law. The resulting equations are evaluated and graphically illustrated as a function of atmospheric CO2 concentration and as a function of temperature. The equations were applied to the thermochemistry of small molecule rubisco-model reactions and series of additional model reactions to illustrate the range of the Gibbs free enthalpy for the effective reversible capture and of the reaction entropy for economic CO2 release at elevated temperature. A favorable capture of free enthalpy is of course a design necessity, but not all exergonic reactions are suitable CO2 capture systems. Successful CO2 capture systems must allow for effective release as well, and this feature is controlled by the reaction entropy. The principle of using a two-pronged capture system to ensure a large negative capture entropy is explained and highlighted in the graphical abstract. It is hoped that the presentation of the numerical examples provides useful guidelines for the design of more efficient capture systems.

  9. Numerical models for high beta magnetohydrodynamic flow

    International Nuclear Information System (INIS)

    Brackbill, J.U.

    1987-01-01

    The fundamentals of numerical magnetohydrodynamics for highly conducting, high-beta plasmas are outlined. The discussions emphasize the physical properties of the flow, and how elementary concepts in numerical analysis can be applied to the construction of finite difference approximations that capture these features. The linear and nonlinear stability of explicit and implicit differencing in time is examined, the origin and effect of numerical diffusion in the calculation of convective transport is described, and a technique for maintaining solenoidality in the magnetic field is developed. Many of the points are illustrated by numerical examples. The techniques described are applicable to the time-dependent, high-beta flows normally encountered in magnetically confined plasmas, plasma switches, and space and astrophysical plasmas. 40 refs

  10. Quickly Creating Interactive Astronomy Illustrations

    Science.gov (United States)

    Slater, Timothy F.

    2015-01-01

    An innate advantage for astronomy teachers is having numerous breathtaking images of the cosmos available to capture students' curiosity, imagination, and wonder. Internet-based astronomy image libraries are numerous and easy to navigate. The Astronomy Picture of the Day, the Hubble Space Telescope image archive, and the NASA Planetary…

  11. Preparing Colorful Astronomical Images and Illustrations

    Science.gov (United States)

    Levay, Z. G.; Frattare, L. M.

    2001-12-01

    We present techniques for using mainstream graphics software, specifically Adobe Photoshop and Illustrator, for producing composite color images and illustrations from astronomical data. These techniques have been used with numerous images from the Hubble Space Telescope to produce printed and web-based news, education and public presentation products as well as illustrations for technical publication. While Photoshop is not intended for quantitative analysis of full dynamic range data (as are IRAF or IDL, for example), we have had much success applying Photoshop's numerous, versatile tools to work with scaled images, masks, text and graphics in multiple semi-transparent layers and channels. These features, along with its user-oriented, visual interface, provide convenient tools to produce high-quality, full-color images and graphics for printed and on-line publication and presentation.

  12. Usage of Numerical Optimization in Wind Turbine Airfoil Design

    Energy Technology Data Exchange (ETDEWEB)

    Grasso, F. [ECN Wind Energy, Petten (Netherlands)

    2011-01-15

    One important key element in the aerodynamic design of wind turbines is the use of specially tailored airfoils to increase the ratio of energy capture to the loading and thereby to reduce the cost of energy. This work is focused on the design of a wind turbine airfoil by using numerical optimization. First, the requirements for this class of airfoils are illustrated and discussed in order to have an exhaustive outline of the complexity of the problem. Then the optimization approach is presented; a gradient-based algorithm is used, coupled with RFOIL solver and a composite Bezier geometrical parameterization. A particularly sensitive point is the choice and implementation of constraints; to formalize the design requirements in the most complete and effective way, the effects of activating specific constraints are discussed. Finally, a numerical example regarding the design of a high-efficiency airfoil for the outer part of a blade is illustrated, and the results are compared with existing wind turbine airfoils.

  13. Analysis of capture-recapture data

    CERN Document Server

    McCrea, Rachel S

    2014-01-01

    An important first step in studying the demography of wild animals is to identify the animals uniquely through applying markings, such as rings, tags, and bands. Once the animals are encountered again, researchers can study different forms of capture-recapture data to estimate features, such as the mortality and size of the populations. Capture-recapture methods are also used in other areas, including epidemiology and sociology.With an emphasis on ecology, Analysis of Capture-Recapture Data covers many modern developments of capture-recapture and related models and methods and places them in the historical context of research from the past 100 years. The book presents both classical and Bayesian methods.A range of real data sets motivates and illustrates the material and many examples illustrate biometry and applied statistics at work. In particular, the authors demonstrate several of the modeling approaches using one substantial data set from a population of great cormorants. The book also discusses which co...

  14. Radiology illustrated. Spine

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Heung Sik; Lee, Joon Woo [Seoul National Univ. Bundang Hospital, Seongnam, Kyonggi-do (Korea, Republic of). Dept. of Radiology; Kwon, Jong Won [Samsung Medical Center, Seoul (Korea, Republic of). Dept. of Radiology

    2014-04-01

    Offers a practical approach to image interpretation for spinal disorders. Includes numerous high-quality radiographic images and schematic illustrations. Will serve as a self-learning book covering daily routine cases from the basic to the advanced. Radiology Illustrated: Spine is an up-to-date, superbly illustrated reference in the style of a teaching file that has been designed specifically to be of value in clinical practice. Common, critical, and rare but distinctive spinal disorders are described succinctly with the aid of images highlighting important features and informative schematic illustrations. The first part of the book, on common spinal disorders, is for radiology residents and other clinicians who are embarking on the interpretation of spinal images. A range of key disorders are then presented, including infectious spondylitis, cervical trauma, spinal cord disorders, spinal tumors, congenital disorders, uncommon degenerative disorders, inflammatory arthritides, and vascular malformations. The third part is devoted to rare but clinically significant spinal disorders with characteristic imaging features, and the book closes by presenting practical tips that will assist in the interpretation of confusing cases.

  15. Depletion and capture: revisiting “The source of water derived from wells"

    Science.gov (United States)

    Konikow, Leonard F.; Leake, Stanley A.

    2014-01-01

    A natural consequence of groundwater withdrawals is the removal of water from subsurface storage, but the overall rates and magnitude of groundwater depletion and capture relative to groundwater withdrawals (extraction or pumpage) have not previously been well characterized. This study assesses the partitioning of long-term cumulative withdrawal volumes into fractions derived from storage depletion and capture, where capture includes both increases in recharge and decreases in discharge. Numerical simulation of a hypothetical groundwater basin is used to further illustrate some of Theis' (1940) principles, particularly when capture is constrained by insufficient available water. Most prior studies of depletion and capture have assumed that capture is unconstrained through boundary conditions that yield linear responses. Examination of real systems indicates that capture and depletion fractions are highly variable in time and space. For a large sample of long-developed groundwater systems, the depletion fraction averages about 0.15 and the capture fraction averages about 0.85 based on cumulative volumes. Higher depletion fractions tend to occur in more arid regions, but the variation is high and the correlation coefficient between average annual precipitation and depletion fraction for individual systems is only 0.40. Because 85% of long-term pumpage is derived from capture in these real systems, capture must be recognized as a critical factor in assessing water budgets, groundwater storage depletion, and sustainability of groundwater development. Most capture translates into streamflow depletion, so it can detrimentally impact ecosystems.

  16. Depletion and capture: revisiting "the source of water derived from wells".

    Science.gov (United States)

    Konikow, L F; Leake, S A

    2014-09-01

    A natural consequence of groundwater withdrawals is the removal of water from subsurface storage, but the overall rates and magnitude of groundwater depletion and capture relative to groundwater withdrawals (extraction or pumpage) have not previously been well characterized. This study assesses the partitioning of long-term cumulative withdrawal volumes into fractions derived from storage depletion and capture, where capture includes both increases in recharge and decreases in discharge. Numerical simulation of a hypothetical groundwater basin is used to further illustrate some of Theis' (1940) principles, particularly when capture is constrained by insufficient available water. Most prior studies of depletion and capture have assumed that capture is unconstrained through boundary conditions that yield linear responses. Examination of real systems indicates that capture and depletion fractions are highly variable in time and space. For a large sample of long-developed groundwater systems, the depletion fraction averages about 0.15 and the capture fraction averages about 0.85 based on cumulative volumes. Higher depletion fractions tend to occur in more arid regions, but the variation is high and the correlation coefficient between average annual precipitation and depletion fraction for individual systems is only 0.40. Because 85% of long-term pumpage is derived from capture in these real systems, capture must be recognized as a critical factor in assessing water budgets, groundwater storage depletion, and sustainability of groundwater development. Most capture translates into streamflow depletion, so it can detrimentally impact ecosystems. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  17. The problem of latent attentional capture: Easy visual search conceals capture by task-irrelevant abrupt onsets.

    Science.gov (United States)

    Gaspelin, Nicholas; Ruthruff, Eric; Lien, Mei-Ching

    2016-08-01

    Researchers are sharply divided regarding whether irrelevant abrupt onsets capture spatial attention. Numerous studies report that they do and a roughly equal number report that they do not. This puzzle has inspired numerous attempts at reconciliation, none gaining general acceptance. The authors propose that abrupt onsets routinely capture attention, but the size of observed capture effects depends critically on how long attention dwells on distractor items which, in turn, depends critically on search difficulty. In a series of spatial cuing experiments, the authors show that irrelevant abrupt onsets produce robust capture effects when visual search is difficult, but not when search is easy. Critically, this effect occurs even when search difficulty varies randomly across trials, preventing any strategic adjustments of the attentional set that could modulate probability of capture by the onset cue. The authors argue that easy visual search provides an insensitive test for stimulus-driven capture by abrupt onsets: even though onsets truly capture attention, the effects of capture can be latent. This observation helps to explain previous failures to find capture by onsets, nearly all of which used an easy visual search. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  18. THE ANALYSIS OF ILLUSTRATIONS IN THE FOURTH CLASS GEOGRAPHY TEXTBOOKS

    Directory of Open Access Journals (Sweden)

    IOANA CHIRCEV

    2014-01-01

    Full Text Available This study focuses on the analysis of the illustrations found in five different Geography textbooks in Romania. The analysis is based on several criteria: number, size, clarity, pedagogical usefulness. The following conclusions have been drawn: the illustrations are numerous; most of the illustrations are too small and unclear to be efficiently used in the teaching activity; the purpose of some materials is purely illustrative; some illustrations are overcharged with details, which prevent children from understanding them. Authors and publishing houses are advised to choose the illustrations in the fourth class Geography textbooks more carefully.

  19. Interatomic Coulombic electron capture

    International Nuclear Information System (INIS)

    Gokhberg, K.; Cederbaum, L. S.

    2010-01-01

    In a previous publication [K. Gokhberg and L. S. Cederbaum, J. Phys. B 42, 231001 (2009)] we presented the interatomic Coulombic electron capture process--an efficient electron capture mechanism by atoms and ions in the presence of an environment. In the present work we derive and discuss the mechanism in detail. We demonstrate thereby that this mechanism belongs to a family of interatomic electron capture processes driven by electron correlation. In these processes the excess energy released in the capture event is transferred to the environment and used to ionize (or to excite) it. This family includes the processes where the capture is into the lowest or into an excited unoccupied orbital of an atom or ion and proceeds in step with the ionization (or excitation) of the environment, as well as the process where an intermediate autoionizing excited resonance state is formed in the capturing center which subsequently deexcites to a stable state transferring its excess energy to the environment. Detailed derivation of the asymptotic cross sections of these processes is presented. The derived expressions make clear that the environment assisted capture processes can be important for many systems. Illustrative examples are presented for a number of model systems for which the data needed to construct the various capture cross sections are available in the literature.

  20. Scenario evolution: Interaction between event tree construction and numerical analyses

    International Nuclear Information System (INIS)

    Barr, G.E.; Barnard, R.W.; Dockery, H.A.; Dunn, E.; MacIntyre, A.T.

    1991-01-01

    Construction of well-posed scenarios for the range of conditions possible at any proposed repository site is a critical first step to assessing total system performance. Even tree construction is the method that is being used to develop potential failure scenarios for the proposed nuclear waste repository at Yucca Mountain. An event tree begins with an initial event or condition. Subsequent events are listed in a sequence, leading eventually to release of radionuclides to the accessible environment. Ensuring the validity of the scenarios requires iteration between problems constructed using scenarios contained in the event tree sequence, experimental results, and numerical analyses. Details not adequately captured within the tree initially may become more apparent as a result of analyses. To illustrate this process, we discuss the iterations used to develop numerical analyses for PACE-90 using basaltic igneous activity and human-intrusion event trees

  1. Roles of Illustrators in Visual Communication of Scientific Knowledge

    Directory of Open Access Journals (Sweden)

    Kana Okawa

    2011-10-01

    Full Text Available Scientific knowledge is the knowledge accumulated by systematic studies and organized by general principles. Visual, verbal, numeric, and other types of representation are used to communicate scientific knowledge. Scientific illustration is the visual representation of objects and concepts in order to record and to convey scientific knowledge(Ford, 1993. There are some discussions on scientific illustrations in history, philosophy and the sociology of science(Burri & Dumit, 2008, but little has been done on the creation of scientific illustrations by illustrators. This study focuses on the creation of scientific illustrations by illustrators. The purpose is to show how illustrators create the visual messages in communications of scientific knowledge. Through analysis of semi-structured interviews with 6 professional illustrators, creators and art directors, it is showed that illustrators select and edit scientific information, add non-scientific information, and organize information into one visual representation of scientific knowledge. The implication of this research will provide a new perspective to multisensory communication of scientific knowledge.

  2. È VIVO: Virtual eruptions at Vesuvius; A multimedia tool to illustrate numerical modeling to a general public

    Science.gov (United States)

    Todesco, Micol; Neri, Augusto; Demaria, Cristina; Marmo, Costantino; Macedonio, Giovanni

    2006-07-01

    Dissemination of scientific results to the general public has become increasingly important in our society. When science deals with natural hazards, public outreach is even more important: on the one hand, it contributes to hazard perception and it is a necessary step toward preparedness and risk mitigation; on the other hand, it contributes to establish a positive link of mutual confidence between scientific community and the population living at risk. The existence of such a link plays a relevant role in hazard communication, which in turn is essential to mitigate the risk. In this work, we present a tool that we have developed to illustrate our scientific results on pyroclastic flow propagation at Vesuvius. This tool, a CD-ROM that we developed joining scientific data with appropriate knowledge in communication sciences is meant to be a first prototype that will be used to test the validity of this approach to public outreach. The multimedia guide contains figures, images of real volcanoes and computer animations obtained through numerical modeling of pyroclastic density currents. Explanatory text, kept as short and simple as possible, illustrates both the process and the methodology applied to study this very dangerous natural phenomenon. In this first version, the CD-ROM will be distributed among selected categories of end-users together with a short questionnaire that we have drawn to test its readability. Future releases will include feedback from the users, further advancement of scientific results as well as a higher degree of interactivity.

  3. Scenario evolution: Interaction between event tree construction and numerical analyses

    International Nuclear Information System (INIS)

    Barr, G.E.; Barnard, R.W.; Dockery, H.A.; Dunn, E.; MacIntyre, A.T.

    1990-01-01

    Construction of well-posed scenarios for the range of conditions possible at any proposed repository site is a critical first step to assessing total system performance. Event tree construction is the method that is being used to develop potential failure scenarios for the proposed nuclear waste repository at Yucca Mountain. An event tree begins with an initial event or condition. Subsequent events are listed in a sequence, leading eventually to release of radionuclides to the accessible environment. Ensuring the validity of the scenarios requires iteration between problems constructed using scenarios contained in the event tree sequence, experimental results, and numerical analyses. Details not adequately captured within the tree initially may become more apparent as a result of analyses. To illustrate this process, the authors discuss the iterations used to develop numerical analyses for PACE-90 (Performance Assessment Calculational Exercises) using basaltic igneous activity and human-intrusion event trees

  4. Vortex-Breakdown-Induced Particle Capture in Branching Junctions.

    Science.gov (United States)

    Ault, Jesse T; Fani, Andrea; Chen, Kevin K; Shin, Sangwoo; Gallaire, François; Stone, Howard A

    2016-08-19

    We show experimentally that a flow-induced, Reynolds number-dependent particle-capture mechanism in branching junctions can be enhanced or eliminated by varying the junction angle. In addition, numerical simulations are used to show that the features responsible for this capture have the signatures of classical vortex breakdown, including an approach flow aligned with the vortex axis and a pocket of subcriticality. We show how these recirculation regions originate and evolve and suggest a physical mechanism for their formation. Furthermore, comparing experiments and numerical simulations, the presence of vortex breakdown is found to be an excellent predictor of particle capture. These results inform the design of systems in which suspended particle accumulation can be eliminated or maximized.

  5. A DG approach to the numerical solution of the Stein-Stein stochastic volatility option pricing model

    Science.gov (United States)

    Hozman, J.; Tichý, T.

    2017-12-01

    Stochastic volatility models enable to capture the real world features of the options better than the classical Black-Scholes treatment. Here we focus on pricing of European-style options under the Stein-Stein stochastic volatility model when the option value depends on the time, on the price of the underlying asset and on the volatility as a function of a mean reverting Orstein-Uhlenbeck process. A standard mathematical approach to this model leads to the non-stationary second-order degenerate partial differential equation of two spatial variables completed by the system of boundary and terminal conditions. In order to improve the numerical valuation process for a such pricing equation, we propose a numerical technique based on the discontinuous Galerkin method and the Crank-Nicolson scheme. Finally, reference numerical experiments on real market data illustrate comprehensive empirical findings on options with stochastic volatility.

  6. Calculations on Electron Capture in Low Energy Ion-Molecule Collisions

    Energy Technology Data Exchange (ETDEWEB)

    Stancil, P.C. [Oak Ridge National Lab., TN (United States); Zygelman, B. [W.M. Keck Lab. for Computational Physics, Univ. of Nevada, Las Vegas, NV (United States); Kirby, K. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)

    1997-12-31

    Recent progress on the application of a quantal, molecular-orbital, close-coupling approach to the calculation of electron capture in collisions of multiply charged ions with molecules is discussed. Preliminary results for single electron capture by N{sup 2+} with H{sub 2} are presented. Electron capture by multiply charged ions colliding with H{sub 2} is an important process in laboratory and astrophysical plasmas. It provides a recombination mechanism for multiply charged ions in x-ray ionized astronomical environments which may have sparse electron and atomic hydrogen abundances. In the divertor region of a tokamak fusion device, charge exchange of impurity ions with H{sub 2} plays a role in the ionization balance and the production of radiative energy loss leading to cooling, X-ray and ultraviolet auroral emission from Jupiter is believed to be due to charge exchange of O and S ions with H{sub 2} in the Jovian atmosphere. Solar wind ions interacting with cometary molecules may have produced the x-rays observed from Comet Hyakutake. In order to model and understand the behavior of these environments, it is necessary to obtain total, electronic state-selective (ESS), and vibrational (or rotational) state-selective (VSS) capture cross sections for collision energies as low as 10 meV/amu to as high as 100 keV/amu in some instances. Fortunately, charge transfer with molecular targets has received considerable experimental attention. Numerous measurements have been made with flow tubes, ion traps, and ion beams. Flow tube and ion trap studies generally provide information on rate coefficients for temperatures between 800 K and 20,000 K. In this article, we report on the progress of our group in implementing a quantum-mechanical Molecular Orbital Close Coupling (MOCC) approach to the study of electron capture by multiply charged ions in collisions with molecules. We illustrate this with a preliminary investigation of Single Electron Capture (SEC) by N{sup 2+} with H

  7. Description and application of capture zone delineation for a wellfield at Hilton Head Island, South Carolina

    Science.gov (United States)

    Landmeyer, J.E.

    1994-01-01

    Ground-water capture zone boundaries for individual pumped wells in a confined aquffer were delineated by using groundwater models. Both analytical and numerical (semi-analytical) models that more accurately represent the $round-water-flow system were used. All models delineated 2-dimensional boundaries (capture zones) that represent the areal extent of groundwater contribution to a pumped well. The resultant capture zones were evaluated on the basis of the ability of each model to realistically rapresent the part of the ground-water-flow system that contributed water to the pumped wells. Analytical models used were based on a fixed radius approach, and induded; an arbitrary radius model, a calculated fixed radius model based on the volumetric-flow equation with a time-of-travel criterion, and a calculated fixed radius model derived from modification of the Theis model with a drawdown criterion. Numerical models used induded the 2-dimensional, finite-difference models RESSQC and MWCAP. The arbitrary radius and Theis analytical models delineated capture zone boundaries that compared least favorably with capture zones delineated using the volumetric-flow analytical model and both numerical models. The numerical models produced more hydrologically reasonable capture zones (that were oriented parallel to the regional flow direction) than the volumetric-flow equation. The RESSQC numerical model computed more hydrologically realistic capture zones than the MWCAP numerical model by accounting for changes in the shape of capture zones caused by multiple-well interference. The capture zone boundaries generated by using both analytical and numerical models indicated that the curnmtly used 100-foot radius of protection around a wellhead in South Carolina is an underestimate of the extent of ground-water capture for pumped wetis in this particular wellfield in the Upper Floridan aquifer. The arbitrary fixed radius of 100 feet was shown to underestimate the upgradient

  8. STS-49 ASEM activity illustrated with PLAID computer graphics

    Science.gov (United States)

    1992-01-01

    STS-49 Endeavour, Orbiter Vehicle (OV) 105, Assembly of Station by Extravehicular Activity (EVA) Methods (ASEM) activity is illustrated with PLAID computer graphics. An extravehicular mobility unit (EMU) suited crewmember, positioned on the remote manipulator system (RMS) manipulator foot restraint (MFR), grabs and maneuvers the multipurpose experiment support structure (MPESS) with truss assembly attached above OV-105's payload bay (PLB) using the steer wheel assembly. The MPESS/ASEM truss structure has been lifted out the sill-mounted payload retention latch assemblies (PRLAs) and will be repositioned in the PRLAs upon completion of handling procedures. Also seen in this illustration are the empty INTELSAT perigee stage cradle structure (aft PLB) and the capture bar grapple fixture stowed on the port side sill longeron.

  9. Ferrofluids: Modeling, numerical analysis, and scientific computation

    Science.gov (United States)

    Tomas, Ignacio

    simplified version of this model and the corresponding numerical scheme we prove (in addition to stability) convergence and existence of solutions as by-product . Throughout this dissertation, we will provide numerical experiments, not only to validate mathematical results, but also to help the reader gain a qualitative understanding of the PDE models analyzed in this dissertation (the MNSE, the Rosenweig's model, and the Two-phase model). In addition, we also provide computational experiments to illustrate the potential of these simple models and their ability to capture basic phenomenological features of ferrofluids, such as the Rosensweig instability for the case of the two-phase model. In this respect, we highlight the incisive numerical experiments with the two-phase model illustrating the critical role of the demagnetizing field to reproduce physically realistic behavior of ferrofluids.

  10. Finite element implementation and numerical issues of strain gradient plasticity with application to metal matrix composites

    DEFF Research Database (Denmark)

    Frederiksson, Per; Gudmundson, Peter; Mikkelsen, Lars Pilgaard

    2009-01-01

    A framework of finite element equations for strain gradient plasticity is presented. The theoretical framework requires plastic strain degrees of freedom in addition to displacements and a plane strain version is implemented into a commercial finite element code. A couple of different elements...... of quadrilateral type are examined and a few numerical issues are addressed related to these elements as well as to strain gradient plasticity theories in general. Numerical results are presented for an idealized cell model of a metal matrix composite under shear loading. It is shown that strengthening due...... to fiber size is captured but strengthening due to fiber shape is not. A few modelling aspects of this problem are discussed as well. An analytic solution is also presented which illustrates similarities to other theories....

  11. Numerical solutions of the semiclassical Boltzmann ellipsoidal-statistical kinetic model equation

    Science.gov (United States)

    Yang, Jaw-Yen; Yan, Chin-Yuan; Huang, Juan-Chen; Li, Zhihui

    2014-01-01

    Computations of rarefied gas dynamical flows governed by the semiclassical Boltzmann ellipsoidal-statistical (ES) kinetic model equation using an accurate numerical method are presented. The semiclassical ES model was derived through the maximum entropy principle and conserves not only the mass, momentum and energy, but also contains additional higher order moments that differ from the standard quantum distributions. A different decoding procedure to obtain the necessary parameters for determining the ES distribution is also devised. The numerical method in phase space combines the discrete-ordinate method in momentum space and the high-resolution shock capturing method in physical space. Numerical solutions of two-dimensional Riemann problems for two configurations covering various degrees of rarefaction are presented and various contours of the quantities unique to this new model are illustrated. When the relaxation time becomes very small, the main flow features a display similar to that of ideal quantum gas dynamics, and the present solutions are found to be consistent with existing calculations for classical gas. The effect of a parameter that permits an adjustable Prandtl number in the flow is also studied. PMID:25104904

  12. Enhanced mutual capture of colored solitons by matched modulator

    Science.gov (United States)

    Feigenbaum, Eyal; Orenstein, Meir

    2004-08-01

    The mutual capture of two colored solitons is enhanced by a modulator, to a level which enables its practical exploitation, e.g., for a read- write mechanism in a soliton buffer. The enhanced capture was analyzed using closed form particle-like soliton perturbation, and verified by numerical simulations. Optimal modulator frequency and modulation depth are obtained. This mutual capture can be utilized for all-optical soliton logic and memory.

  13. Between Certainty and Uncertainty Statistics and Probability in Five Units with Notes on Historical Origins and Illustrative Numerical Examples

    CERN Document Server

    Laudański, Ludomir M

    2013-01-01

    „Between Certainty & Uncertainty” is a one-of–a-kind short course on statistics for students, engineers  and researchers.  It is a fascinating introduction to statistics and probability with notes on historical origins and 80 illustrative numerical examples organized in the five units:   ·         Chapter 1  Descriptive Statistics:  Compressing small samples, basic averages - mean and variance, their main properties including God’s proof; linear transformations and z-scored statistics .   ·         Chapter 2 Grouped data: Udny Yule’s concept of qualitative and quantitative variables. Grouping these two kinds of data. Graphical tools. Combinatorial rules and qualitative variables.  Designing frequency histogram. Direct and coded evaluation of quantitative data. Significance of percentiles.   ·         Chapter 3 Regression and correlation: Geometrical distance and equivalent distances in two orthogonal directions  as a prerequisite to the concept of two regressi...

  14. Energy capture and storage in asymmetrically multistable modular structures inspired by skeletal muscle

    Science.gov (United States)

    Kidambi, Narayanan; Harne, Ryan L.; Wang, K. W.

    2017-08-01

    The remarkable versatility and adaptability of skeletal muscle that arises from the assembly of its nanoscale cross-bridges into micro-scale assemblies known as sarcomeres provides great inspiration for the development of advanced adaptive structures and material systems. Motivated by the capability of cross-bridges to capture elastic strain energy to improve the energetic efficiency of sudden movements and repeated motions, and by models of cross-bridge power stroke motions and sarcomere contractile behaviors that incorporate asymmetric, bistable potential energy landscapes, this research develops and studies modular mechanical structures that trap and store energy in higher-energy configurations. Modules exhibiting tailorable asymmetric bistability are first designed and fabricated, revealing how geometric parameters influence the asymmetry of the resulting double-well energy landscapes. These experimentally-observed characteristics are then investigated with numerical and analytical methods to characterize the dynamics of asymmetrically bistable modules. The assembly of such modules into greater structures generates complex, multi-well energy landscapes with stable system configurations exhibiting different quantities of stored elastic potential energy. Dynamic analyses illustrate the ability of these structures to capture a portion of the initial kinetic energy due to impulsive excitations as recoverable strain potential energy, and reveal how stiffness parameters, damping, and the presence of thermal noise in micro- and nano-scale applications influence energy capture behaviors. The insights gained could foster the development of advanced structural/material systems inspired by skeletal muscle, including actuators that effectively capture, store, and release energy, as well as adaptive, robust, and reusable armors and protective devices.

  15. A Methodology for a Sustainable CO2 Capture and Utilization Network

    DEFF Research Database (Denmark)

    Frauzem, Rebecca; Fjellerup, Kasper; Gani, Rafiqul

    2015-01-01

    hydrogenation highlights the application. This case study illustrates the utility of the utilization network and elements of the methodology being developed. In addition, the conversion process is linked with carbon capture to evaluate the overall sustainability. Finally, the production of the other raw...... of Climate Change. New York: Cambridge University Press, 2007. [2] J. Wilcox, Carbon Capture. New York: Springer, 2012....

  16. Current status of fast-neutron-capture calculations

    International Nuclear Information System (INIS)

    Gardner, D.G.

    1982-01-01

    This work is primarily concerned with the calculation of neutron capture cross sections and capture gamma-ray spectra, in the framework of the Hauser-Feshbach statistical model and for neutrons from the resonance region up to several MeV. An argument is made that, for applied purposes such as constructing evaluated cross-section libraries, nonstatistical capture mechanisms may be completely neglected at low energies and adequately approximated at high energies in a simple way. The use of gamma-ray strength functions to obtain radiation widths is emphasized. Using the reaction 89 Y + n as an example, the problems encountered in trying to construct a case that could be run equivalently on two different nuclear reaction codes are illustrated, and the effects produced by certain parameter variations are discussed

  17. A numerical study of adaptive space and time discretisations for Gross-Pitaevskii equations.

    Science.gov (United States)

    Thalhammer, Mechthild; Abhau, Jochen

    2012-08-15

    the numerical approximation captures correctly the behaviour of the analytical solution. Further illustrations for Gross-Pitaevskii equations with a focusing nonlinearity or a sharp Gaussian as initial condition, respectively, complement the numerical study.

  18. Numerical study on determining formation porosity using a boron capture gamma ray technique and MCNP.

    Science.gov (United States)

    Liu, Juntao; Zhang, Feng; Wang, Xinguang; Han, Fei; Yuan, Zhelong

    2014-12-01

    Formation porosity can be determined using the boron capture gamma ray counting ratio with a near to far detector in a pulsed neutron-gamma element logging tool. The thermal neutron distribution, boron capture gamma spectroscopy and porosity response for formations with different water salinity and wellbore diameter characteristics were simulated using the Monte Carlo method. We found that a boron lining improves the signal-to-noise ratio and that the boron capture gamma ray counting ratio has a higher sensitivity for determining porosity than total capture gamma. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Numerical Gram-Schmidt orthonormalization

    International Nuclear Information System (INIS)

    Werneth, Charles M; Dhar, Mallika; Maung, Khin Maung; Sirola, Christopher; Norbury, John W

    2010-01-01

    A numerical Gram-Schmidt orthonormalization procedure is presented for constructing an orthonormal basis function set from a non-orthonormal set, when the number of basis functions is large. This method will provide a pedagogical illustration of the Gram-Schmidt procedure and can be presented in classes on numerical methods or computational physics.

  20. Numerical methods using Matlab

    CERN Document Server

    Lindfield, George

    2012-01-01

    Numerical Methods using MATLAB, 3e, is an extensive reference offering hundreds of useful and important numerical algorithms that can be implemented into MATLAB for a graphical interpretation to help researchers analyze a particular outcome. Many worked examples are given together with exercises and solutions to illustrate how numerical methods can be used to study problems that have applications in the biosciences, chaos, optimization, engineering and science across the board. Numerical Methods using MATLAB, 3e, is an extensive reference offering hundreds of use

  1. Radiative electron capture by channeled ions

    International Nuclear Information System (INIS)

    Pitarke, J.M.; Ritchie, R.H.; Tennessee Univ., Knoxville, TN

    1989-01-01

    Considerable experimental data have been accumulated relative to the emission of photons accompanying electron capture by swift, highly stripped atoms penetrating crystalline matter under channeling conditions. Recent data suggest that the photon energies may be less than that expected from simple considerations of transitions from the valence band of the solid to hydrogenic states on the moving ion. We have studied theoretically the impact parameter dependence of the radiative electron capture (REC) process, the effect of the ion's wake and the effect of capture from inner shells of the solid on the photon emission probability, using a statistical approach. Numerical comparisons of our results with experiment are made. 13 refs., 6 figs

  2. Capture of Planetesimals into a Circumterrestrial Swarm

    Science.gov (United States)

    Weidenschilling, S. J.

    1985-01-01

    The lunar origin model considered in this report involves processing of protolunar material through a circumterrestrial swarm of particles. Once such a swarm has formed, it can gain mass by capturing infalling planetesimals and ejecta from giant impacts on the Earth, although the angular momentum supply from these sources remains a problem. The first stage of formation of a geocentric swarm by capture of planetesimals from initially heliocentric orbits is examined. The only plausible capture mechanism that is not dependent on very low approach velocities is the mutual collision of planetesimals passing within Earth's sphere of influence. The dissipation of energy in inelastic collisions or accretion events changes the value of the Jacobi parameter, allowing capture into bound geocentric orbits. This capture scenario was tested directly by many body numerical integration of planetesimal orbits in near Earth space.

  3. Five-dimensional black hole capture cross sections

    International Nuclear Information System (INIS)

    Gooding, Cisco; Frolov, Andrei V.

    2008-01-01

    We study scattering and capture of particles by a rotating black hole in the five-dimensional spacetime described by the Myers-Perry metric. The equations of geodesic motion are integrable, and allow us to calculate capture conditions for a free particle sent towards a black hole from infinity. We introduce a three-dimensional impact parameter describing asymptotic initial conditions in the scattering problem for a given initial velocity. The capture surface in impact parameter space is a sphere for a nonrotating black hole, and is deformed for a rotating black hole. We obtain asymptotic expressions that describe such deformations for small rotational parameters, and use numerical calculations to investigate the arbitrary rotation case, which allows us to visualize the capture surface as extremal rotation is approached

  4. Capturing Individual Uptake: Toward a Disruptive Research Methodology

    Science.gov (United States)

    Bastian, Heather

    2015-01-01

    This article presents and illustrates a qualitative research methodology for studies of uptake. It does so by articulating a theoretical framework for qualitative investigations of uptake and detailing a research study designed to invoke and capture students' uptakes in a first-year writing classroom. The research design sought to make uptake…

  5. Selection of the optimum condition for electron capture detector operation

    International Nuclear Information System (INIS)

    Lasa, J.; Korus, A.

    1974-01-01

    A method of determination of the optimal work conditions for the electron capture detector is presented in the paper. Physical phenomena which occur in the detector, as well as the energetic dependence of the electron attachment process are taken into consideration. The influence of the kind of carrier gas, temperature, and the parameters of the supplied voltage in both direct and pulse methods on average values of electron energy is described. Dependence of the sensitivity of the electron capture detector on the carrier gas and the polarizing voltage is illustrated for the Model DNW-300 electron capture detector produced in Poland. Practical indications for selecting optimal conditions of electron capture detector operation are given at the end of the paper. (author)

  6. CHAOTIC CAPTURE OF NEPTUNE TROJANS

    International Nuclear Information System (INIS)

    Nesvorny, David; Vokrouhlicky, David

    2009-01-01

    Neptune Trojans (NTs) are swarms of outer solar system objects that lead/trail planet Neptune during its revolutions around the Sun. Observations indicate that NTs form a thick cloud of objects with a population perhaps ∼10 times more numerous than that of Jupiter Trojans and orbital inclinations reaching ∼25 deg. The high inclinations of NTs are indicative of capture instead of in situ formation. Here we study a model in which NTs were captured by Neptune during planetary migration when secondary resonances associated with the mean-motion commensurabilities between Uranus and Neptune swept over Neptune's Lagrangian points. This process, known as chaotic capture, is similar to that previously proposed to explain the origin of Jupiter's Trojans. We show that chaotic capture of planetesimals from an ∼35 Earth-mass planetesimal disk can produce a population of NTs that is at least comparable in number to that inferred from current observations. The large orbital inclinations of NTs are a natural outcome of chaotic capture. To obtain the ∼4:1 ratio between high- and low-inclination populations suggested by observations, planetary migration into a dynamically excited planetesimal disk may be required. The required stirring could have been induced by Pluto-sized and larger objects that have formed in the disk.

  7. Self-similar radiation from numerical Rosenau-Hyman compactons

    International Nuclear Information System (INIS)

    Rus, Francisco; Villatoro, Francisco R.

    2007-01-01

    The numerical simulation of compactons, solitary waves with compact support, is characterized by the presence of spurious phenomena, as numerically induced radiation, which is illustrated here using four numerical methods applied to the Rosenau-Hyman K(p, p) equation. Both forward and backward radiations are emitted from the compacton presenting a self-similar shape which has been illustrated graphically by the proper scaling. A grid refinement study shows that the amplitude of the radiations decreases as the grid size does, confirming its numerical origin. The front velocity and the amplitude of both radiations have been studied as a function of both the compacton and the numerical parameters. The amplitude of the radiations decreases exponentially in time, being characterized by a nearly constant scaling exponent. An ansatz for both the backward and forward radiations corresponding to a self-similar function characterized by the scaling exponent is suggested by the present numerical results

  8. Monte Carlo based dosimetry and treatment planning for neutron capture therapy of brain tumors

    International Nuclear Information System (INIS)

    Zamenhof, R.G.; Brenner, J.F.; Wazer, D.E.; Madoc-Jones, H.; Clement, S.D.; Harling, O.K.; Yanch, J.C.

    1990-01-01

    Monte Carlo based dosimetry and computer-aided treatment planning for neutron capture therapy have been developed to provide the necessary link between physical dosimetric measurements performed on the MITR-II epithermal-neutron beams and the need of the radiation oncologist to synthesize large amounts of dosimetric data into a clinically meaningful treatment plan for each individual patient. Monte Carlo simulation has been employed to characterize the spatial dose distributions within a skull/brain model irradiated by an epithermal-neutron beam designed for neutron capture therapy applications. The geometry and elemental composition employed for the mathematical skull/brain model and the neutron and photon fluence-to-dose conversion formalism are presented. A treatment planning program, NCTPLAN, developed specifically for neutron capture therapy, is described. Examples are presented illustrating both one and two-dimensional dose distributions obtainable within the brain with an experimental epithermal-neutron beam, together with beam quality and treatment plan efficacy criteria which have been formulated for neutron capture therapy. The incorporation of three-dimensional computed tomographic image data into the treatment planning procedure is illustrated

  9. Introduction to precise numerical methods

    CERN Document Server

    Aberth, Oliver

    2007-01-01

    Precise numerical analysis may be defined as the study of computer methods for solving mathematical problems either exactly or to prescribed accuracy. This book explains how precise numerical analysis is constructed. The book also provides exercises which illustrate points from the text and references for the methods presented. All disc-based content for this title is now available on the Web. · Clearer, simpler descriptions and explanations ofthe various numerical methods· Two new types of numerical problems; accurately solving partial differential equations with the included software and computing line integrals in the complex plane.

  10. Capture reactions into borromean two-proton systems at rp-waiting points

    DEFF Research Database (Denmark)

    Hove, D.; Jensen, A. S.; Fynbo, H. O. U.

    2016-01-01

    of the radiative capture reactions can be determined. We present numerical results for $E1$ and $E2$ photon emission, and discuss occurrence preferences in general as well as relative sizes of these most likely processes. Finally, we present narrow estimated intervals for the proton capture rates relevant...

  11. Elastic full waveform inversion based on the homogenization method: theoretical framework and 2-D numerical illustrations

    Science.gov (United States)

    Capdeville, Yann; Métivier, Ludovic

    2018-05-01

    Seismic imaging is an efficient tool to investigate the Earth interior. Many of the different imaging techniques currently used, including the so-called full waveform inversion (FWI), are based on limited frequency band data. Such data are not sensitive to the true earth model, but to a smooth version of it. This smooth version can be related to the true model by the homogenization technique. Homogenization for wave propagation in deterministic media with no scale separation, such as geological media, has been recently developed. With such an asymptotic theory, it is possible to compute an effective medium valid for a given frequency band such that effective waveforms and true waveforms are the same up to a controlled error. In this work we make the link between limited frequency band inversion, mainly FWI, and homogenization. We establish the relation between a true model and an FWI result model. This relation is important for a proper interpretation of FWI images. We numerically illustrate, in the 2-D case, that an FWI result is at best the homogenized version of the true model. Moreover, it appears that the homogenized FWI model is quite independent of the FWI parametrization, as long as it has enough degrees of freedom. In particular, inverting for the full elastic tensor is, in each of our tests, always a good choice. We show how the homogenization can help to understand FWI behaviour and help to improve its robustness and convergence by efficiently constraining the solution space of the inverse problem.

  12. Sampling strategies to capture single-cell heterogeneity

    OpenAIRE

    Satwik Rajaram; Louise E. Heinrich; John D. Gordan; Jayant Avva; Kathy M. Bonness; Agnieszka K. Witkiewicz; James S. Malter; Chloe E. Atreya; Robert S. Warren; Lani F. Wu; Steven J. Altschuler

    2017-01-01

    Advances in single-cell technologies have highlighted the prevalence and biological significance of cellular heterogeneity. A critical question is how to design experiments that faithfully capture the true range of heterogeneity from samples of cellular populations. Here, we develop a data-driven approach, illustrated in the context of image data, that estimates the sampling depth required for prospective investigations of single-cell heterogeneity from an existing collection of samples. ...

  13. Influence of wetting layer wave functions on carrier capture in quantum dots

    DEFF Research Database (Denmark)

    Markussen, Troels; Kristensen, Philip; Tromborg, Bjarne

    2005-01-01

    This work numerically solves the effective mass Schrodinger equation and shows that the capture times are strongly influenced by details of the continuum states not accounted for by the approximate wave functions. Results show that calculations of capture time for phonon mediated carrier capture...... from a wetting layer into a quantum dot depend critically on the approximations used for the wetting layer wave functions....

  14. Salmonella capture using orbiting magnetic microbeads

    Science.gov (United States)

    Owen, Drew; Ballard, Matthew; Mills, Zachary; Hanasoge, Srinivas; Hesketh, Peter; Alexeev, Alexander

    2014-11-01

    Using three-dimensional simulations and experiments, we examine capture of salmonella from a complex fluid sample flowing through a microfluidic channel. Capture is performed using orbiting magnetic microbeads, which can easily be extracted from the system for analysis after salmonella capture. Numerical simulations are used to model the dynamics of the system, which consists of a microchannel filled with a viscous fluid, model salmonella, magnetic microbeads and a series of angled parallel ridges lining the top of the microchannel. Simulations provide a statistical measure of the ability of the system to capture target salmonella. Our modeling findings guide the design of a lab-on-a-chip experimental device to be used for the detection of salmonella from complex food samples, allowing for the detection of the bacteria at the food source and preventing the consumption of contaminated food. Such a device can be used as a generic platform for the detection of a variety of biomaterials from complex fluids. This work is supported by a grant from the United States Department of Agriculture.

  15. CAPTURE OF TROJANS BY JUMPING JUPITER

    International Nuclear Information System (INIS)

    Nesvorný, David; Vokrouhlický, David; Morbidelli, Alessandro

    2013-01-01

    Jupiter Trojans are thought to be survivors of a much larger population of planetesimals that existed in the planetary region when planets formed. They can provide important constraints on the mass and properties of the planetesimal disk, and its dispersal during planet migration. Here, we tested a possibility that the Trojans were captured during the early dynamical instability among the outer planets (aka the Nice model), when the semimajor axis of Jupiter was changing as a result of scattering encounters with an ice giant. The capture occurs in this model when Jupiter's orbit and its Lagrange points become radially displaced in a scattering event and fall into a region populated by planetesimals (that previously evolved from their natal transplanetary disk to ∼5 AU during the instability). Our numerical simulations of the new capture model, hereafter jump capture, satisfactorily reproduce the orbital distribution of the Trojans and their total mass. The jump capture is potentially capable of explaining the observed asymmetry in the number of leading and trailing Trojans. We find that the capture probability is (6-8) × 10 –7 for each particle in the original transplanetary disk, implying that the disk contained (3-4) × 10 7 planetesimals with absolute magnitude H disk ∼ 14-28 M Earth , is consistent with the mass deduced from recent dynamical simulations of the planetary instability.

  16. Thermal neutron capture cross sections resonance integrals and g-factors

    International Nuclear Information System (INIS)

    Mughabghab, S.F.

    2003-02-01

    The thermal radiative capture cross sections and resonance integrals of elements and isotopes with atomic numbers from 1 to 83 (as well as 232 Th and 238 U) have been re-evaluated by taking into consideration all known pertinent data published since 1979. This work has been undertaken as part of an IAEA co-ordinated research project on 'Prompt capture gamma-ray activation analysis'. Westcott g-factors for radiative capture cross sections at a temperature of 300K were computed by utilizing the INTER code and ENDF-B/VI (Release 8) library files. The temperature dependence of the Westcott g-factor is illustrated for 113 Cd, 124 Xe and 157 Gd at temperatures of 150, 294 and 400K. Comparisons have also been made of the newly evaluated capture cross sections of 6 Li, 7 Li, 12 C and 207 Pb with those determined by the k 0 method. (author)

  17. A Generalized Estimating Equations Approach to Model Heterogeneity and Time Dependence in Capture-Recapture Studies

    Directory of Open Access Journals (Sweden)

    Akanda Md. Abdus Salam

    2017-03-01

    Full Text Available Individual heterogeneity in capture probabilities and time dependence are fundamentally important for estimating the closed animal population parameters in capture-recapture studies. A generalized estimating equations (GEE approach accounts for linear correlation among capture-recapture occasions, and individual heterogeneity in capture probabilities in a closed population capture-recapture individual heterogeneity and time variation model. The estimated capture probabilities are used to estimate animal population parameters. Two real data sets are used for illustrative purposes. A simulation study is carried out to assess the performance of the GEE estimator. A Quasi-Likelihood Information Criterion (QIC is applied for the selection of the best fitting model. This approach performs well when the estimated population parameters depend on the individual heterogeneity and the nature of linear correlation among capture-recapture occasions.

  18. Numerical solutions of ideal quantum gas dynamical flows governed by semiclassical ellipsoidal-statistical distribution.

    Science.gov (United States)

    Yang, Jaw-Yen; Yan, Chih-Yuan; Diaz, Manuel; Huang, Juan-Chen; Li, Zhihui; Zhang, Hanxin

    2014-01-08

    The ideal quantum gas dynamics as manifested by the semiclassical ellipsoidal-statistical (ES) equilibrium distribution derived in Wu et al. (Wu et al . 2012 Proc. R. Soc. A 468 , 1799-1823 (doi:10.1098/rspa.2011.0673)) is numerically studied for particles of three statistics. This anisotropic ES equilibrium distribution was derived using the maximum entropy principle and conserves the mass, momentum and energy, but differs from the standard Fermi-Dirac or Bose-Einstein distribution. The present numerical method combines the discrete velocity (or momentum) ordinate method in momentum space and the high-resolution shock-capturing method in physical space. A decoding procedure to obtain the necessary parameters for determining the ES distribution is also devised. Computations of two-dimensional Riemann problems are presented, and various contours of the quantities unique to this ES model are illustrated. The main flow features, such as shock waves, expansion waves and slip lines and their complex nonlinear interactions, are depicted and found to be consistent with existing calculations for a classical gas.

  19. Numerical solutions of ideal quantum gas dynamical flows governed by semiclassical ellipsoidal-statistical distribution

    Science.gov (United States)

    Yang, Jaw-Yen; Yan, Chih-Yuan; Diaz, Manuel; Huang, Juan-Chen; Li, Zhihui; Zhang, Hanxin

    2014-01-01

    The ideal quantum gas dynamics as manifested by the semiclassical ellipsoidal-statistical (ES) equilibrium distribution derived in Wu et al. (Wu et al. 2012 Proc. R. Soc. A 468, 1799–1823 (doi:10.1098/rspa.2011.0673)) is numerically studied for particles of three statistics. This anisotropic ES equilibrium distribution was derived using the maximum entropy principle and conserves the mass, momentum and energy, but differs from the standard Fermi–Dirac or Bose–Einstein distribution. The present numerical method combines the discrete velocity (or momentum) ordinate method in momentum space and the high-resolution shock-capturing method in physical space. A decoding procedure to obtain the necessary parameters for determining the ES distribution is also devised. Computations of two-dimensional Riemann problems are presented, and various contours of the quantities unique to this ES model are illustrated. The main flow features, such as shock waves, expansion waves and slip lines and their complex nonlinear interactions, are depicted and found to be consistent with existing calculations for a classical gas. PMID:24399919

  20. Numerical Feedback Stabilization with Applications to Networks

    Directory of Open Access Journals (Sweden)

    Simone Göttlich

    2017-01-01

    Full Text Available The focus is on the numerical consideration of feedback boundary control problems for linear systems of conservation laws including source terms. We explain under which conditions the numerical discretization can be used to design feedback boundary values for network applications such as electric transmission lines or traffic flow systems. Several numerical examples illustrate the properties of the results for different types of networks.

  1. Numerical models for fluid-grains interactions: opportunities and limitations

    Science.gov (United States)

    Esteghamatian, Amir; Rahmani, Mona; Wachs, Anthony

    2017-06-01

    In the framework of a multi-scale approach, we develop numerical models for suspension flows. At the micro scale level, we perform particle-resolved numerical simulations using a Distributed Lagrange Multiplier/Fictitious Domain approach. At the meso scale level, we use a two-way Euler/Lagrange approach with a Gaussian filtering kernel to model fluid-solid momentum transfer. At both the micro and meso scale levels, particles are individually tracked in a Lagrangian way and all inter-particle collisions are computed by a Discrete Element/Soft-sphere method. The previous numerical models have been extended to handle particles of arbitrary shape (non-spherical, angular and even non-convex) as well as to treat heat and mass transfer. All simulation tools are fully-MPI parallel with standard domain decomposition and run on supercomputers with a satisfactory scalability on up to a few thousands of cores. The main asset of multi scale analysis is the ability to extend our comprehension of the dynamics of suspension flows based on the knowledge acquired from the high-fidelity micro scale simulations and to use that knowledge to improve the meso scale model. We illustrate how we can benefit from this strategy for a fluidized bed, where we introduce a stochastic drag force model derived from micro-scale simulations to recover the proper level of particle fluctuations. Conversely, we discuss the limitations of such modelling tools such as their limited ability to capture lubrication forces and boundary layers in highly inertial flows. We suggest ways to overcome these limitations in order to enhance further the capabilities of the numerical models.

  2. On the hydrodynamics of archer fish jumping out of the water: Integrating experiments with numerical simulations

    Science.gov (United States)

    Sotiropoulos, Fotis; Angelidis, Dionysios; Mendelson, Leah; Techet, Alexandra

    2017-11-01

    Evolution has enabled fish to develop a range of thrust producing mechanisms to allow skillful movement and give them the ability to catch prey or avoid danger. Several experimental and numerical studies have been performed to investigate how complex maneuvers are executed and develop bioinspired strategies for aquatic robot design. We will discuss recent numerical advances toward the development of a computational framework for performing turbulent, two-phase flow, fluid-structure-interaction (FSI) simulations to investigate the dynamics of aquatic jumpers. We will also discuss the integration of such numerics with high-speed imaging and particle image velocimetry data to reconstruct anatomic fish models and prescribe realistic kinematics of fish motion. The capabilities of our method will be illustrated by applying it to simulate the motion of a small scale archer fish jumping out of the water to capture prey. We will discuss the rich vortex dynamics emerging during the hovering, rapid upward and gliding phases. The simulations will elucidate the thrust production mechanisms by the movement of the pectoral and anal fins and we will show that the fins significantly contribute to the rapid acceleration.

  3. Radiology illustrated. Pediatric radiology

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In-One (ed.) [Seoul National Univ. College of Medicine (Korea, Republic of). Dept. of Radiology

    2014-11-01

    Depicts characteristic imaging findings of common and uncommon diseases in the pediatric age group. Will serve as an ideal diagnostic reference in daily practice. Offers an excellent teaching aid, with numerous high-quality illustrations. This case-based atlas presents images depicting the findings typically observed when imaging a variety of common and uncommon diseases in the pediatric age group. The cases are organized according to anatomic region, covering disorders of the brain, spinal cord, head and neck, chest, cardiovascular system, gastrointestinal system, genitourinary system, and musculoskeletal system. Cases are presented in a form resembling teaching files, and the images are accompanied by concise informative text. The goal is to provide a diagnostic reference suitable for use in daily routine by both practicing radiologists and radiology residents or fellows. The atlas will also serve as a teaching aide and a study resource, and will offer pediatricians and surgeons guidance on the clinical applications of pediatric imaging.

  4. Classical description of the electron capture to the continuum cusp formation in ion-atom collisions

    International Nuclear Information System (INIS)

    Illescas, Clara; Pons, B.; Riera, A.

    2002-01-01

    Classical calculations are used to describe the dynamics of the electron capture to the continuum (ECC) cusp formation in H + +He collisions. We illustrate the frontier character of the ECC electrons between capture and ionization, and confirm that it is a temporary capture, through projectile focusing, that is responsible for the ECC cusp. Furthermore, the cusp is not a divergence smoothed by the experiment, and is slightly shifted from the impact-velocity value because of the residual pull from the target after ionization. This shift is larger the smaller the nuclear velocity

  5. Illustrator CC digital classroom

    CERN Document Server

    Smith, Jennifer

    2013-01-01

    A complete training package lets you learn Adobe Illustrator CC at your own speed Adobe Illustrator is the leading drawing and illustration software used to create artwork for a variety of media. This book-and-DVD package provides 13 self-paced lessons that get you up to speed on the latest version of Illustrator (Creative Cloud). Step-by-step instructions in the full-color book are supported by video tutorials on the DVD. Together, these tools will help you learn Adobe Illustrator basics, essential skills, and all the new capabilities in Illustrator CC-in no time.  Includes step-by-step in

  6. Debunching and Capture in the LEB for the SSC

    Energy Technology Data Exchange (ETDEWEB)

    Mahale, N.; Furman, M.

    1991-05-01

    The authors present the details of the capture process in the Low Energy Booster (LEB) for the SSC. They consider only the longitudinal dynamics. Space charge forces are computed quasistatically. The beam pipe is considered to be perfectly conducting. With respect to maximizing the capture efficiency and minimizing the space charge tune spread, initial few milliseconds are very important. They present only the first few milliseconds of the cycle, during which space charge effects are significant. For the numerical simulation they use the code ESME.

  7. Numerical modelling of the HAB Energy Buoy: Stage 1

    DEFF Research Database (Denmark)

    Kurniawan, Adi

    This report presents the results of the first stage of the project "Numerical modelling of the HAB Energy Buoy". The objectives of this stage are to develop a numerical model of the HAB Energy Buoy, a self-reacting wave energy device consisting of two heaving bodies, and to investigate a number...... and a summary of the main findings is presented. A numerical model of the HAB Energy Buoy has been developed in the frequency domain using two alternative formulations of the equations of motion. The model is capable of predicting the power capture, motion response, and power take-off loads of the device...... configuration are imposed to give a more realistic prediction of the power capture and help ensure a fair comparison. Recommendations with regard to the HAB design are finally suggested....

  8. An Efficient numerical method to calculate the conductivity tensor for disordered topological matter

    Science.gov (United States)

    Garcia, Jose H.; Covaci, Lucian; Rappoport, Tatiana G.

    2015-03-01

    We propose a new efficient numerical approach to calculate the conductivity tensor in solids. We use a real-space implementation of the Kubo formalism where both diagonal and off-diagonal conductivities are treated in the same footing. We adopt a formulation of the Kubo theory that is known as Bastin formula and expand the Green's functions involved in terms of Chebyshev polynomials using the kernel polynomial method. Within this method, all the computational effort is on the calculation of the expansion coefficients. It also has the advantage of obtaining both conductivities in a single calculation step and for various values of temperature and chemical potential, capturing the topology of the band-structure. Our numerical technique is very general and is suitable for the calculation of transport properties of disordered systems. We analyze how the method's accuracy varies with the number of moments used in the expansion and illustrate our approach by calculating the transverse conductivity of different topological systems. T.G.R, J.H.G and L.C. acknowledge Brazilian agencies CNPq, FAPERJ and INCT de Nanoestruturas de Carbono, Flemish Science Foundation for financial support.

  9. Neutron capture cross section measurements: case of lutetium isotopes

    International Nuclear Information System (INIS)

    Roig, O.; Meot, V.; Belier, G.

    2011-01-01

    The neutron radiative capture is a nuclear reaction that occurs in the presence of neutrons on all isotopes and on a wide energy range. The neutron capture range on Lutetium isotopes, presented here, illustrates the variety of measurements leading to the determination of cross sections. These measurements provide valuable fundamental data needed for the stockpile stewardship program, as well as for nuclear astrophysics and nuclear structure. Measurements, made in France or in United-States, involving complex detectors associated with very rare targets have significantly improved the international databases and validated models of nuclear reactions. We present results concerning the measurement of neutron radiative capture on Lu 173 , Lu 175 , Lu 176 and Lu 177m , the measurement of the probability of gamma emission in the substitution reaction Yb 174 (He 3 ,pγ)Lu 176 . The measurement of neutron cross sections on Lu 177m have permitted to highlight the process of super-elastic scattering

  10. Sustainable Capture: Concepts for Managing Stream-Aquifer Systems.

    Science.gov (United States)

    Davids, Jeffrey C; Mehl, Steffen W

    2015-01-01

    Most surface water bodies (i.e., streams, lakes, etc.) are connected to the groundwater system to some degree so that changes to surface water bodies (either diversions or importations) can change flows in aquifer systems, and pumping from an aquifer can reduce discharge to, or induce additional recharge from streams, springs, and lakes. The timescales of these interactions are often very long (decades), making sustainable management of these systems difficult if relying only on observations of system responses. Instead, management scenarios are often analyzed based on numerical modeling. In this paper we propose a framework and metrics that can be used to relate the Theis concepts of capture to sustainable measures of stream-aquifer systems. We introduce four concepts: Sustainable Capture Fractions, Sustainable Capture Thresholds, Capture Efficiency, and Sustainable Groundwater Storage that can be used as the basis for developing metrics for sustainable management of stream-aquifer systems. We demonstrate their utility on a hypothetical stream-aquifer system where pumping captures both streamflow and discharge to phreatophytes at different amounts based on pumping location. In particular, Capture Efficiency (CE) can be easily understood by both scientists and non-scientist alike, and readily identifies vulnerabilities to sustainable stream-aquifer management when its value exceeds 100%. © 2014, National Ground Water Association.

  11. Advanced Dynamics Analytical and Numerical Calculations with MATLAB

    CERN Document Server

    Marghitu, Dan B

    2012-01-01

    Advanced Dynamics: Analytical and Numerical Calculations with MATLAB provides a thorough, rigorous presentation of kinematics and dynamics while using MATLAB as an integrated tool to solve problems. Topics presented are explained thoroughly and directly, allowing fundamental principles to emerge through applications from areas such as multibody systems, robotics, spacecraft and design of complex mechanical devices. This book differs from others in that it uses symbolic MATLAB for both theory and applications. Special attention is given to solutions that are solved analytically and numerically using MATLAB. The illustrations and figures generated with MATLAB reinforce visual learning while an abundance of examples offer additional support. This book also: Provides solutions analytically and numerically using MATLAB Illustrations and graphs generated with MATLAB reinforce visual learning for students as they study Covers modern technical advancements in areas like multibody systems, robotics, spacecraft and des...

  12. Numerical Calabi-Yau metrics

    International Nuclear Information System (INIS)

    Douglas, Michael R.; Karp, Robert L.; Lukic, Sergio; Reinbacher, Rene

    2008-01-01

    We develop numerical methods for approximating Ricci flat metrics on Calabi-Yau hypersurfaces in projective spaces. Our approach is based on finding balanced metrics and builds on recent theoretical work by Donaldson. We illustrate our methods in detail for a one parameter family of quintics. We also suggest several ways to extend our results

  13. Relativistic acceleration of captured particles by a longitudinal wave in a slightly inhomogeneous plasma

    International Nuclear Information System (INIS)

    Erokhin, N.S.; Zol'nikova, N.N.; Mikhajlovskaya, L.A.

    1991-01-01

    Relativistic acceleration of charged particles, captured by a longitudinal wave in a slightly inhomogeneous plasma without an external magnetic field is considered numerically and analytically. It is shown that with the growth of the plasma inhomogeneity parameter the maximum energy of accelerated captured particles exponentially increases. Attention is paid to the possibility of 'eternal' confinement and, respectively, unlimited acceleration of captured particles by an undamped longitudinal wave in a plasma without a magnetic field

  14. Grenz rays. An illustrated guide to the theory and practical application of soft x-rays

    International Nuclear Information System (INIS)

    Graham, D.; Thomson, J.

    1980-01-01

    The uses of soft x-rays (Grenz rays) as investigative tools in the fields of medical diagnosis, botany, art, entomology and forensic science, are discussed and the practical applications of the techniques illustrated by numerous photographs. (U.K.)

  15. Numerical Verification Of Equilibrium Chemistry

    International Nuclear Information System (INIS)

    Piro, Markus; Lewis, Brent; Thompson, William T.; Simunovic, Srdjan; Besmann, Theodore M.

    2010-01-01

    A numerical tool is in an advanced state of development to compute the equilibrium compositions of phases and their proportions in multi-component systems of importance to the nuclear industry. The resulting software is being conceived for direct integration into large multi-physics fuel performance codes, particularly for providing boundary conditions in heat and mass transport modules. However, any numerical errors produced in equilibrium chemistry computations will be propagated in subsequent heat and mass transport calculations, thus falsely predicting nuclear fuel behaviour. The necessity for a reliable method to numerically verify chemical equilibrium computations is emphasized by the requirement to handle the very large number of elements necessary to capture the entire fission product inventory. A simple, reliable and comprehensive numerical verification method is presented which can be invoked by any equilibrium chemistry solver for quality assurance purposes.

  16. A numerical study of adaptive space and time discretisations for Gross–Pitaevskii equations

    Science.gov (United States)

    Thalhammer, Mechthild; Abhau, Jochen

    2012-01-01

    As a basic principle, benefits of adaptive discretisations are an improved balance between required accuracy and efficiency as well as an enhancement of the reliability of numerical computations. In this work, the capacity of locally adaptive space and time discretisations for the numerical solution of low-dimensional nonlinear Schrödinger equations is investigated. The considered model equation is related to the time-dependent Gross–Pitaevskii equation arising in the description of Bose–Einstein condensates in dilute gases. The performance of the Fourier-pseudo spectral method constrained to uniform meshes versus the locally adaptive finite element method and of higher-order exponential operator splitting methods with variable time stepsizes is studied. Numerical experiments confirm that a local time stepsize control based on a posteriori local error estimators or embedded splitting pairs, respectively, is effective in different situations with an enhancement either in efficiency or reliability. As expected, adaptive time-splitting schemes combined with fast Fourier transform techniques are favourable regarding accuracy and efficiency when applied to Gross–Pitaevskii equations with a defocusing nonlinearity and a mildly varying regular solution. However, the numerical solution of nonlinear Schrödinger equations in the semi-classical regime becomes a demanding task. Due to the highly oscillatory and nonlinear nature of the problem, the spatial mesh size and the time increments need to be of the size of the decisive parameter 0Fourier pseudo-spectral and the finite element method. Nevertheless, for smaller parameter values locally adaptive time discretisations facilitate to determine the time stepsizes sufficiently small in order that the numerical approximation captures correctly the behaviour of the analytical solution. Further illustrations for Gross–Pitaevskii equations with a focusing nonlinearity or a sharp Gaussian as initial condition, respectively

  17. Trends in Illustration: A digital approach to large format illustrations ...

    African Journals Online (AJOL)

    In view of this, this study uses Adobe Photoshop CS4, a digital draw and paint tool, to illustrate some of the notable folktales in Igbo oral tradition. Vector and Raster techniques of computer graphics will be employed and discussed. Basic information on digital illustration will also be enumerated in the project. This piece of ...

  18. Evaluation of XHVRB for Capturing Explosive Shock Desensitization

    Science.gov (United States)

    Tuttle, Leah; Schmitt, Robert; Kittell, Dave; Harstad, Eric

    2017-06-01

    Explosive shock desensitization phenomena have been recognized for some time. It has been demonstrated that pressure-based reactive flow models do not adequately capture the basic nature of the explosive behavior. Historically, replacing the local pressure with a shock captured pressure has dramatically improved the numerical modeling approaches. Models based upon shock pressure or functions of entropy have recently been developed. A pseudo-entropy based formulation using the History Variable Reactive Burn model, as proposed by Starkenberg, was implemented into the Eulerian shock physics code CTH. Improvements in the shock capturing algorithm were made. The model is demonstrated to reproduce single shock behavior consistent with published pop plot data. It is also demonstrated to capture a desensitization effect based on available literature data, and to qualitatively capture dead zones from desensitization in 2D corner turning experiments. This models shows promise for use in modeling and simulation problems that are relevant to the desensitization phenomena. Issues are identified with the current implementation and future work is proposed for improving and expanding model capabilities. Sandia National Laboratories is a multi-mission laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. DOE's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  19. Numerical linear algebra theory and applications

    CERN Document Server

    Beilina, Larisa; Karchevskii, Mikhail

    2017-01-01

    This book combines a solid theoretical background in linear algebra with practical algorithms for numerical solution of linear algebra problems. Developed from a number of courses taught repeatedly by the authors, the material covers topics like matrix algebra, theory for linear systems of equations, spectral theory, vector and matrix norms combined with main direct and iterative numerical methods, least squares problems, and eigen problems. Numerical algorithms illustrated by computer programs written in MATLAB® are also provided as supplementary material on SpringerLink to give the reader a better understanding of professional numerical software for the solution of real-life problems. Perfect for a one- or two-semester course on numerical linear algebra, matrix computation, and large sparse matrices, this text will interest students at the advanced undergraduate or graduate level.

  20. Neutron capture cross section measurements: case of lutetium isotopes; Mesures de donnees de sections efficaces de capture radiative de neutrons: application au cas du lutecium

    Energy Technology Data Exchange (ETDEWEB)

    Roig, O.; Meot, V.; Belier, G. [CEA Bruyeres-le-Chatel, 91 (France)

    2011-07-15

    The neutron radiative capture is a nuclear reaction that occurs in the presence of neutrons on all isotopes and on a wide energy range. The neutron capture range on Lutetium isotopes, presented here, illustrates the variety of measurements leading to the determination of cross sections. These measurements provide valuable fundamental data needed for the stockpile stewardship program, as well as for nuclear astrophysics and nuclear structure. Measurements, made in France or in United-States, involving complex detectors associated with very rare targets have significantly improved the international databases and validated models of nuclear reactions. We present results concerning the measurement of neutron radiative capture on Lu{sup 173}, Lu{sup 175}, Lu{sup 176} and Lu{sup 177m}, the measurement of the probability of gamma emission in the substitution reaction Yb{sup 174}(He{sup 3},p{gamma})Lu{sup 176}. The measurement of neutron cross sections on Lu{sup 177m} have permitted to highlight the process of super-elastic scattering

  1. The numerical solution of boundary value problems over an infinite domain

    International Nuclear Information System (INIS)

    Shepherd, M.; Skinner, R.

    1976-01-01

    A method is presented for the numerical solution of boundary value problems over infinite domains. An example that illustrates also the strength and accuracy of a numerical procedure for calculating Green's functions is described in detail

  2. Numerical integration of asymptotic solutions of ordinary differential equations

    Science.gov (United States)

    Thurston, Gaylen A.

    1989-01-01

    Classical asymptotic analysis of ordinary differential equations derives approximate solutions that are numerically stable. However, the analysis also leads to tedious expansions in powers of the relevant parameter for a particular problem. The expansions are replaced with integrals that can be evaluated by numerical integration. The resulting numerical solutions retain the linear independence that is the main advantage of asymptotic solutions. Examples, including the Falkner-Skan equation from laminar boundary layer theory, illustrate the method of asymptotic analysis with numerical integration.

  3. Numerical simulation for the influence of laser-induced plasmas addition on air mass capture of hypersonic inlet

    Science.gov (United States)

    Zhao, Wei; Dou, Zhiguo; Li, Qian

    2012-03-01

    The theory of laser-induced plasmas addition to hypersonic airflow off a vehicle to increase air mass capture and improve the performance of hypersonic inlets at Mach numbers below the design value is explored. For hypersonic vehicles, when flying at mach numbers lower than the design one, we can increase the mass capture ratio of inlet through laser-induced plasmas injection to the hypersonic flow upstream of cowl lip to form a virtual cowl. Based on the theory, the model of interaction between laser-induced plasmas and hypersonic flow was established. The influence on the effect of increasing mass capture ratio was studied at different positions of laser-induced plasmas region for the external compression hypersonic inlet at Mach 5 while the design value is 6, the power of plasmas was in the range of 1-8mJ. The main results are as follows: 1. the best location of the plasma addition region is near the intersection of the nose shock of the vehicle with the continuation of the cowl line, and slightly below that line. In that case, the shock generated by the heating is close to the shock that is a reflection of the vehicle nose shock off the imaginary solid surface-extension of the cowl. 2. Plasma addition does increase mass capture, and the effect becomes stronger as more energy is added, the peak value appeared when the power of plasma was about 4mJ, when the plasma energy continues to get stronger, the mass capture will decline slowly.

  4. Engineering cholesterol-based fibers for antibody immobilization and cell capture

    Science.gov (United States)

    Cohn, Celine

    In 2015, the United States is expected to have nearly 600,000 deaths attributed to cancer. Of these 600,000 deaths, 90% will be a direct result of cancer metastasis, the spread of cancer throughout the body. During cancer metastasis, circulating tumor cells (CTCs) are shed from primary tumors and migrate through bodily fluids, establishing secondary cancer sites. As cancer metastasis is incredibly lethal, there is a growing emphasis on developing "liquid biopsies" that can screen peripheral blood, search for and identify CTCs. One popular method for capturing CTCs is the use of a detection platform with antibodies specifically suited to recognize and capture cancer cells. These antibodies are immobilized onto the platform and can then bind and capture cells of interest. However, current means to immobilize antibodies often leave them with drastically reduced function. The antibodies are left poorly suited for cell capture, resulting in low cell capture efficiencies. This body of work investigates the use of lipid-based fibers to immobilize proteins in a way that retains protein function, ultimately leading to increased cell capture efficiencies. The resulting increased efficiencies are thought to arise from the retained three-dimensional structure of the protein as well as having a complete coating of the material surface with antibodies that are capable of interacting with their antigens. It is possible to electrospin cholesterol-based fibers that are similar in design to the natural cell membrane, providing proteins a more natural setting during immobilization. Such fibers have been produced from cholesterol-based cholesteryl succinyl silane (CSS). These fibers have previously illustrated a keen aptitude for retaining protein function and increasing cell capture. Herein the work focuses on three key concepts. First, a model is developed to understand the immobilization mechanism used by electrospun CSS fibers. The antibody immobilization and cell capturing

  5. Geoillustrator - fast sketching of geological illustrations and animations

    Science.gov (United States)

    Patel, Daniel; Langeland, Tor; Solteszova, Veronika

    2014-05-01

    We present our research results in the Geoillustrator project. The project has been going for four years and is ending in March. It was aimed at developing a rapid sketching tool for generating geological illustrations and animations for understanding the processes that have led to a current subsurface configuration. The sketching tool facilitates effective dissemination of ideas, e.g. through generation of interactive geo-scientific illustrations for interdisciplinary communication and communication to decision makers, media and lay persons. This can improve work processes in early phases of oil and gas exploration where critical decisions have to be taken based on limited information. It is a challenge for involved specialists in early exploration phases to externalize their ideas, and effectively achieve consensus in multidisciplinary working groups. In these work processes, a tool for rapid sketching of geology would be very useful for expressing geological hypotheses and creating and comparing different evolution scenarios. Often, decisions are influenced by factors that are not relevant, e.g. the geologists who produce the most polished illustrations of their hypothesis have a higher probability for getting their theories through to decision makers as it is more clearly communicated. This results in a competitive advantage for geologists who are skilled in creating illustrations. Having a tool that would lift the ability of all geologists to express their ideas to an equal level would result in more alternatives and better foundation for decision making. Digital sketching will also allow capturing otherwise lost material which can constitute a large amount of mental work and ideas. The results of sketching are currently scrapped as paper or erased from the blackboard or exist only as rough personal sketches. By using a digital sketching tool, the sketches can be exported to a form usable in modelling tools used in later phases of exploration. Currently, no

  6. Numerical Solution of Fuzzy Differential Equations by Runge-Kutta Verner Method

    Directory of Open Access Journals (Sweden)

    T. Jayakumar

    2015-01-01

    Full Text Available In this paper we study the numerical methods for Fuzzy Differential equations by an application of the Runge-Kutta Verner method for fuzzy differential equations. We prove a convergence result and give numerical examples to illustrate the theory.

  7. Numerical modelling in non linear fracture mechanics

    Directory of Open Access Journals (Sweden)

    Viggo Tvergaard

    2007-07-01

    Full Text Available Some numerical studies of crack propagation are based on using constitutive models that accountfor damage evolution in the material. When a critical damage value has been reached in a materialpoint, it is natural to assume that this point has no more carrying capacity, as is done numerically in the elementvanish technique. In the present review this procedure is illustrated for micromechanically based materialmodels, such as a ductile failure model that accounts for the nucleation and growth of voids to coalescence, and a model for intergranular creep failure with diffusive growth of grain boundary cavities leading to micro-crack formation. The procedure is also illustrated for low cycle fatigue, based on continuum damage mechanics. In addition, the possibility of crack growth predictions for elastic-plastic solids using cohesive zone models to represent the fracture process is discussed.

  8. Differing perspectives of major oil firms on future energy developments: An illustrative framework

    International Nuclear Information System (INIS)

    Chang Youngho; Yong Jiayun

    2007-01-01

    This study develops a framework to analyse the perspectives of major oil firms in terms of their perceptions of current energy developments and projections of future energy potentials, and illustrates their views on the possibility of a paradigm shift in fuel use. The three A's themes-availability of resource (AV), applicability of technology (AP) and acceptability by society (AC)-make up the analytical framework. Divergence in oil firms' behaviour and perspectives are captured by the 3-A triangle that illustrates how the four largest oil firms in the world balance their stakes among the three A's. ExxonMobil's position is markedly skewed towards the theme of AV, whilst BP has the most balanced approach among the four. Shell and Total both share a similarly shaped 3-A triangle with more stakes placed on the theme of AP. The results would imply that a paradigm shift in resource use or a full-scale transition to a backstop technology is unlikely in the coming decades

  9. Numerical Simulation on the Liquid Bridge Formation by the Applied Electric Pulse

    Science.gov (United States)

    Hong, Jin Seok; Kang, In Seok

    2010-11-01

    In this work, liquid bridge (LB) formation by the applied electric field is analyzed numerically. Numerical simulation captures the temporal behavior of liquid surface during the LB formation between a top plate and a bottom nozzle. Numerical results show the three stages of LB formation; interface elevation, impact/fast spreading and slow spreading/stabilization. The effect of the applied voltage pulse is also studied in terms of minimal electrical energy for LB formation. Non-linear behavior such as bubble trapping at the impact of liquid to plate is also captured and explained qualitatively. Grounded and floating plate is considered. The wetting criterion for LB formation is suggested and explained in terms of capillary pressure. The linear decrease of the final contact radius with the top plate contact angle is shown from the numerical results. In addition, the effects of the liquid properties on the dynamics are briefly discussed.

  10. Predicting individual differences in decision-making process from signature movement styles: an illustrative study of leaders

    OpenAIRE

    Connors, Brenda L.; Rende, Richard; Colton, Timothy J.

    2013-01-01

    There has been a surge of interest in examining the utility of methods for capturing individual differences in decision-making style. We illustrate the potential offered by Movement Pattern Analysis (MPA), an observational methodology that has been used in business and by the US Department of Defense to record body movements that provide predictive insight into individual differences in decision-making motivations and actions. Twelve military officers participated in an intensive 2-h intervie...

  11. Numeric invariants from multidimensional persistence

    Energy Technology Data Exchange (ETDEWEB)

    Skryzalin, Jacek [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Carlsson, Gunnar [Stanford Univ., Stanford, CA (United States)

    2017-05-19

    In this paper, we analyze the space of multidimensional persistence modules from the perspectives of algebraic geometry. We first build a moduli space of a certain subclass of easily analyzed multidimensional persistence modules, which we construct specifically to capture much of the information which can be gained by using multidimensional persistence over one-dimensional persistence. We argue that the global sections of this space provide interesting numeric invariants when evaluated against our subclass of multidimensional persistence modules. Lastly, we extend these global sections to the space of all multidimensional persistence modules and discuss how the resulting numeric invariants might be used to study data.

  12. Presence capture cameras - a new challenge to the image quality

    Science.gov (United States)

    Peltoketo, Veli-Tapani

    2016-04-01

    Commercial presence capture cameras are coming to the markets and a new era of visual entertainment starts to get its shape. Since the true presence capturing is still a very new technology, the real technical solutions are just passed a prototyping phase and they vary a lot. Presence capture cameras have still the same quality issues to tackle as previous phases of digital imaging but also numerous new ones. This work concentrates to the quality challenges of presence capture cameras. A camera system which can record 3D audio-visual reality as it is has to have several camera modules, several microphones and especially technology which can synchronize output of several sources to a seamless and smooth virtual reality experience. Several traditional quality features are still valid in presence capture cameras. Features like color fidelity, noise removal, resolution and dynamic range create the base of virtual reality stream quality. However, co-operation of several cameras brings a new dimension for these quality factors. Also new quality features can be validated. For example, how the camera streams should be stitched together with 3D experience without noticeable errors and how to validate the stitching? The work describes quality factors which are still valid in the presence capture cameras and defines the importance of those. Moreover, new challenges of presence capture cameras are investigated in image and video quality point of view. The work contains considerations how well current measurement methods can be used in presence capture cameras.

  13. Asteroid Redirect Robotic Mission: Robotic Boulder Capture Option Overview

    Science.gov (United States)

    Mazanek, Daniel D.; Merrill, Raymond G.; Belbin, Scott P.; Reeves, David M.; Earle, Kevin D.; Naasz, Bo J.; Abell, Paul A.

    2014-01-01

    The National Aeronautics and Space Administration (NASA) is currently studying an option for the Asteroid Redirect Robotic Mission (ARRM) that would capture a multi-ton boulder (typically 2-4 meters in size) from the surface of a large (is approximately 100+ meter) Near-Earth Asteroid (NEA) and return it to cislunar space for subsequent human and robotic exploration. This alternative mission approach, designated the Robotic Boulder Capture Option (Option B), has been investigated to determine the mission feasibility and identify potential differences from the initial ARRM concept of capturing an entire small NEA (4-10 meters in size), which has been designated the Small Asteroid Capture Option (Option A). Compared to the initial ARRM concept, Option B allows for centimeter-level characterization over an entire large NEA, the certainty of target NEA composition type, the ability to select the boulder that is captured, numerous opportunities for mission enhancements to support science objectives, additional experience operating at a low-gravity planetary body including extended surface contact, and the ability to demonstrate future planetary defense strategies on a hazardous-size NEA. Option B can leverage precursor missions and existing Agency capabilities to help ensure mission success by targeting wellcharacterized asteroids and can accommodate uncertain programmatic schedules by tailoring the return mass.

  14. Capture orbits around asteroids by hitting zero-velocity curves

    Science.gov (United States)

    Wang, Wei; Yang, Hongwei; Zhang, Wei; Ma, Guangfu

    2017-12-01

    The problem of capturing a spacecraft from a heliocentric orbit into a high parking orbit around binary asteroids is investigated in the current study. To reduce the braking Δ V, a new capture strategy takes advantage of the three-body gravity of the binary asteroid to lower the inertial energy before applying the Δ V. The framework of the circular restricted three-body problem (CR3BP) is employed for the binary asteroid system. The proposed capture strategy is based on the mechanism by which inertial energy can be decreased sharply near zero-velocity curves (ZVCs). The strategy has two steps, namely, hitting the target ZVC and raising the periapsis by a small Δ V at the apoapsis. By hitting the target ZVC, the positive inertial energy decreases and becomes negative. Using a small Δ V, the spacecraft inserts into a bounded orbit around the asteroid. In addition, a rotating mass dipole model is employed for elongated asteroids, which leads to dynamics similar to that of the CR3BP. With this approach, the proposed capture strategy can be applied to elongated asteroids. Numerical simulations validate that the proposed capture strategy is applicable for the binary asteroid 90 Antiope and the elongated asteroid 216 Kleopatra.

  15. Angular distribution coefficients for γ-ray polarization produced in polarized capture reactions

    International Nuclear Information System (INIS)

    Wulf, E.A.; Guillemette, J.; Weller, H.R.; Seyler, R.G.

    1999-01-01

    The previous publications have dealt with the angular momentum formalism of both linear and circularly polarized photons in (γ, x) reactions on both polarized and unpolarized targets, and the inverse (capture) reactions initiated by polarized beams. In the present work, utilizing the general formalism of Welton, the authors deal with the linear polarization of the γ-rays which are produced in capture reactions on unpolarized targets, including the possibility of having incident polarized spin 1/2 projectiles. These capture reactions are denoted by a(rvec x, rvec L)c, where rvec x is the incident polarized spin 1/2 projectile and rvec L represents the outgoing polarized γ-ray. They present here the formalism in a convenient form, display a sample table of coefficients, and illustrate its use by means of several examples. A FORTRAN code will be made available for generating similar coefficients for other reactions

  16. The influence of anisotropy on capture zone analysis

    International Nuclear Information System (INIS)

    Hansen, K.

    1995-01-01

    Approximately 50,000 gallons of various grades of gasoline and aviation fuel were leaked into silty clay overburden overlying phyllite of the Wissahickon Formation. Pumping tests and measurements of water table recovery from recovery and production wells suggested that elliptical cones of depression were caused by anisotropic groundwater flow in steeply dipping fractures trending between N60 degree E and N75 degree E which were formed by weathered metamorphic foliation. Fracture trace analysis, outcrop measurements, borehole camera surveys, straddle packer testing, and test excavations supported this conceptual model for hydraulic conductivity. Using both quantitative and semi-quantitative methods, the magnitude of anisotropy was calculated from both pumping tests and water table recovery data. Calculated anisotropies showed variations related to the particular method of analysis. Simulations of capture zones using numerical techniques indicated that anisotropic conditions had produced actual capture zones influenced by groundwater flow not orthogonal to equipotential lines. Capture zone shapes were significantly distorted along the primary axis of anisotropy within the range of variation in anisotropy (n) measured by the different analysis methods. Using the mean value of anisotropy from this site (n = 14), actual recovery well capture areas were subsequently corrected for anisotropic effects. The use of capture areas corrected for the mean value of anisotropy enabled more effective placement of subsequent recovery wells. The relatively consistent foliation of rocks in the Wissahickon Formation suggested that capture zone correction should be considered when developing recovery strategies in aquifer systems where anisotropic conditions are likely

  17. Capturing spatial and temporal patterns of widespread, extreme flooding across Europe

    Science.gov (United States)

    Busby, Kathryn; Raven, Emma; Liu, Ye

    2013-04-01

    Statistical characterisation of physical hazards is an integral part of probabilistic catastrophe models used by the reinsurance industry to estimate losses from large scale events. Extreme flood events are not restricted by country boundaries which poses an issue for reinsurance companies as their exposures often extend beyond them. We discuss challenges and solutions that allow us to appropriately capture the spatial and temporal dependence of extreme hydrological events on a continental-scale, which in turn enables us to generate an industry-standard stochastic event set for estimating financial losses for widespread flooding. By presenting our event set methodology, we focus on explaining how extreme value theory (EVT) and dependence modelling are used to account for short, inconsistent hydrological data from different countries, and how to make appropriate statistical decisions that best characterise the nature of flooding across Europe. The consistency of input data is of vital importance when identifying historical flood patterns. Collating data from numerous sources inherently causes inconsistencies and we demonstrate our robust approach to assessing the data and refining it to compile a single consistent dataset. This dataset is then extrapolated using a parameterised EVT distribution to estimate extremes. Our method then captures the dependence of flood events across countries using an advanced multivariate extreme value model. Throughout, important statistical decisions are explored including: (1) distribution choice; (2) the threshold to apply for extracting extreme data points; (3) a regional analysis; (4) the definition of a flood event, which is often linked with reinsurance industry's hour's clause; and (5) handling of missing values. Finally, having modelled the historical patterns of flooding across Europe, we sample from this model to generate our stochastic event set comprising of thousands of events over thousands of years. We then briefly

  18. Influence of wetting-layer wave functions on phonon-mediated carrier capture into self-assembled quantum dots

    DEFF Research Database (Denmark)

    Markussen, Troels; Kristensen, Philip Trøst; Tromborg, Bjarne

    2006-01-01

    Models of carrier dynamics in quantum dots rely strongly on adequate descriptions of the carrier wave functions. In this work we numerically solve the one-band effective mass Schrodinger equation to calculate the capture times of phonon-mediated carrier capture into self-assembled quantum dots. C....... Comparing with results obtained using approximate carrier wave functions, we demonstrate that the capture times are strongly influenced by properties of the wetting layer wave functions not accounted for by earlier theoretical analyses....

  19. Electron Capture Dissociation of Weakly Bound Polypeptide Polycationic Complexes

    DEFF Research Database (Denmark)

    Haselmann, Kim F; Jørgensen, Thomas J D; Budnik, Bogdan A

    2002-01-01

    as well as specific complexes of modified glycopeptide antibiotics with their target peptide. The weak nature of bonding is substantiated by blackbody infrared dissociation, low-energy collisional excitation and force-field simulations. The results are consistent with a non-ergodic ECD cleavage mechanism.......We have previously reported that, in electron capture dissociation (ECD), rupture of strong intramolecular bonds in weakly bound supramolecular aggregates can proceed without dissociation of weak intermolecular bonds. This is now illustrated on a series of non-specific peptide-peptide dimers...

  20. CAPTURE OF PLANETESIMALS BY GAS DRAG FROM CIRCUMPLANETARY DISKS

    International Nuclear Information System (INIS)

    Fujita, Tetsuya; Ohtsuki, Keiji; Suetsugu, Ryo; Tanigawa, Takayuki

    2013-01-01

    Growing giant planets have circumplanetary disks around them in the late stage of their formation if their mass is sufficiently large. We examine capture of relatively large planetesimals that are decoupled from the gas inflow, due to gas drag from a circumplanetary disk of a growing giant planet. Assuming that the structure of the circumplanetary disk is axisymmetric, and solving the three-body problem including gas drag, we perform analytic and numerical calculations for capture of planetesimals. When planetesimal random velocity is small, planetesimals approaching in the retrograde direction are more easily captured, owing to their larger velocity relative to the gas. Planetesimals with large orbital inclinations interact with the disk for a short period of time and show lower capture rates. The effect of ablation on capture rates seems insignificant, although mass loss due to ablation would be significant in the case of high random velocity. We also examine the effect of non-uniform radial distribution of planetesimals in the protoplanetary disk due to gap opening by the planet. When the random velocity of planetesimals is small, the planetesimal capture rate decreases rapidly as the half width of the gap in the planetesimal disk increases from two planetary Hill radii to three planetary Hill radii; planetesimals with low random velocities cannot approach the planet in the case of a sufficiently wide gap. Our results show that the radial distribution and random velocity of planetesimals in the protoplanetary disk are essentially important for the understanding of capture of planetesimals by circumplanetary disks

  1. Numerical solution of High-kappa model of superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Karamikhova, R. [Univ. of Texas, Arlington, TX (United States)

    1996-12-31

    We present formulation and finite element approximations of High-kappa model of superconductivity which is valid in the high {kappa}, high magnetic field setting and accounts for applied magnetic field and current. Major part of this work deals with steady-state and dynamic computational experiments which illustrate our theoretical results numerically. In our experiments we use Galerkin discretization in space along with Backward-Euler and Crank-Nicolson schemes in time. We show that for moderate values of {kappa}, steady states of the model system, computed using the High-kappa model, are virtually identical with results computed using the full Ginzburg-Landau (G-L) equations. We illustrate numerically optimal rates of convergence in space and time for the L{sup 2} and H{sup 1} norms of the error in the High-kappa solution. Finally, our numerical approximations demonstrate some well-known experimentally observed properties of high-temperature superconductors, such as appearance of vortices, effects of increasing the applied magnetic field and the sample size, and the effect of applied constant current.

  2. Injection and capture simulations for a high intensity proton synchrotron

    International Nuclear Information System (INIS)

    Cho, Y.; Lessner, E.; Symon, K.; Univ. of Wisconsin, Madison, WI

    1994-01-01

    The injection and capture processes in a high intensity, rapid cycling, proton synchrotron are simulated by numerical integration. The equations of motion suitable for rapid numerical simulation are derived so as to maintain symplecticity and second-order accuracy. By careful bookkeeping, the authors can, for each particle that is lost, determine its initial phase space coordinates. They use this information as a guide for different injection schemes and rf voltage programming, so that a minimum of particle losses and dilution are attained. A fairly accurate estimate of the space charge fields is required, as they influence considerably the particle distribution and reduce the capture efficiency. Since the beam is represented by a relatively coarse ensemble of macro particles, the authors study several methods of reducing the statistical fluctuations while retaining the fine structure (high intensity modulations) of the beam distribution. A pre-smoothing of the data is accomplished by the cloud-in-cell method. The program is checked by making sure that it gives correct answers in the absence of space charge, and that it reproduces the negative mass instability properly. Results of simulations for stationary distributions are compared to their analytical predictions. The capture efficiency for the rapid-cycling synchrotron is analyzed with respect to variations in the injected beam energy spread, bunch length, and rf programming

  3. Transient modeling of electrochemically assisted CO2 capture and release

    DEFF Research Database (Denmark)

    Singh, Shobhana; Stechel, Ellen B.; Buttry, Daniel A.

    2017-01-01

    to analyze the time-dependent behavior of CO2 capture and electro-migration transport across the cell length. Given high nonlinearity of the system, we used a finite element method (FEM) to numerically solve the coupled mass transport equations. The model describes the concentration profiles by taking......The present work aims to develop a model of a new electrochemical CO2 separation and release technology. We present a one-dimensional transient model of an electrochemical cell for point source CO2 capture and release, which mainly focuses on the simultaneous mass transport and complex chemical...... reactions associated with the separation process. For concreteness, we use an ionic liquid (IL) with 2 M thiolate anion (RS−) in 1 M disulfide (RSSR) as an electrolyte in the electrochemical cell to capture, transport and release CO2 under standard operating conditions. We computationally solved the model...

  4. On the complexity of numerical analysis

    DEFF Research Database (Denmark)

    Miltersen, Peter Bro; Allender, Eric; Burgisser, Peter

    2009-01-01

    an integer N, decide whether N>0. • In the Blum-Shub-Smale model, polynomial time computation over the reals (on discrete inputs) is polynomial-time equivalent to PosSLP, when there are only algebraic constants. We conjecture that using transcendental constants provides no additional power, beyond nonuniform...... reductions to PosSLP, and we present some preliminary results supporting this conjecture. • The Generic Task of Numerical Computation is also polynomial-time equivalent to PosSLP. We prove that PosSLP lies in the counting hierarchy. Combining this with work of Tiwari, we obtain that the Euclidean Traveling......We study two quite different approaches to understanding the complexity of fundamental problems in numerical analysis: • The Blum-Shub-Smale model of computation over the reals. • A problem we call the “Generic Task of Numerical Computation,” which captures an aspect of doing numerical computation...

  5. Functionalized metal organic frameworks for effective capture of radioactive organic iodides

    KAUST Repository

    Li, Baiyan

    2017-06-27

    Highly efficient capture of radioactive organic iodides (ROIs) from off-gas mixtures remains a substantial challenge for nuclear waste treatment. Current materials utilized for ROI sequestration suffer from low capacity, high cost (e.g. use of noble metals), and poor recyclability. Recently, we have developed a new strategy to tackle this challenge by functionalizing MOF materials with tertiary amines to create molecular traps for the effective capture and removal of ROIs (e.g. radioactive methyl iodide) from nuclear wastes. To further enhance the uptake capacity and performance of CH3I capture by ROI molecular traps, herein, we carry out a systematic study to investigate the effect of different amine molecules on ROI capture. The results demonstrate a record-high CH3I saturation uptake capacity of 80% for MIL-101-Cr-DMEDA at 150 °C, which is 5.3 times that of Ag0@MOR (15 wt%), a leading adsorbent material for capturing ROIs during nuclear fuel reprocessing. Furthermore, the CH3I decontamination factors (DFs) for MIL-101-Cr-DMEDA are as high as 5000 under simulated reprocessing conditions, largely exceeding that of facility regulatory requirements (DF = 3000). In addition, MIL-101-Cr-DMEDA can be recycled without loss of capacity, illustrating yet another advantage compared to known industrial adsorbents, which are typically of a

  6. Numerical methods in simulation of resistance welding

    DEFF Research Database (Denmark)

    Nielsen, Chris Valentin; Martins, Paulo A.F.; Zhang, Wenqi

    2015-01-01

    Finite element simulation of resistance welding requires coupling betweenmechanical, thermal and electrical models. This paper presents the numerical models and theircouplings that are utilized in the computer program SORPAS. A mechanical model based onthe irreducible flow formulation is utilized...... a resistance welding point of view, the most essential coupling between the above mentioned models is the heat generation by electrical current due to Joule heating. The interaction between multiple objects is anothercritical feature of the numerical simulation of resistance welding because it influences...... thecontact area and the distribution of contact pressure. The numerical simulation of resistancewelding is illustrated by a spot welding example that includes subsequent tensile shear testing...

  7. Numerical studies of the linear theta pinch

    International Nuclear Information System (INIS)

    Brackbill, J.U.; Menzel, M.T.; Barnes, D.C.

    1975-01-01

    Aspects of several physical problems associated with linear theta pinches were studied using recently developed numerical methods for the solution of the nonlinear equations for time-dependent magnetohydrodynamic flow in two- and three-dimensions. The problems studied include the propagation of end-loss produced rarefaction waves, the flow produced in a proposed injection experiment geometry, and the linear growth and nonlinear saturation of instabilities in rotating plasmas, all in linear geometries. The studies illustrate how numerical computations aid in flow visualization, and how the small amplitude behavior and nonlinear fate of plasmas in unstable equilibria can be connected through the numerical solution of the dynamical equations. (auth)

  8. Coincidental match of numerical simulation and physics

    Science.gov (United States)

    Pierre, B.; Gudmundsson, J. S.

    2010-08-01

    Consequences of rapid pressure transients in pipelines range from increased fatigue to leakages and to complete ruptures of pipeline. Therefore, accurate predictions of rapid pressure transients in pipelines using numerical simulations are critical. State of the art modelling of pressure transient in general, and water hammer in particular include unsteady friction in addition to the steady frictional pressure drop, and numerical simulations rely on the method of characteristics. Comparison of rapid pressure transient calculations by the method of characteristics and a selected high resolution finite volume method highlights issues related to modelling of pressure waves and illustrates that matches between numerical simulations and physics are purely coincidental.

  9. Collisional Cascades Following Triton's Capture

    Science.gov (United States)

    Cuk, Matija; Hamilton, Douglas P.; Stewart-Mukhopadhyay, Sarah T.

    2017-10-01

    Neptune's moon Triton is widely thought to have been captured from heliocentric orbit, most likely through binary dissociation (Agnor and Hamilton, 2006). Triton's original eccentric orbit must have been subsequently circularized by satellite tides (Goldreich et al. 1989). Cuk and Gladman (2005) found that Kozai oscillations make early tidal evolution inefficient, and have proposed that collisions between Triton and debris from pre-existing satellites was the dominant mechanism of shrinking Triton's large post-capture orbit. However, Cuk and Hamilton (DPS 2016), using numerical simulations and results of Stewart and Leinhardt (2012), have found that collisions between regular satellites are unlikely to be destructive, while collisions between prograde moons and Triton are certainly erosive if not catastrophic. An obvious outcome would be pre-existing moon material gradually grinding down Triton and making it reaccrete in the local Laplace plane, in conflict with Triton's large current inclination. We propose that the crucial ingredient for understanding the early evolution of the Neptunian system are the collisions between the moons and the prograde and retrograde debris originating from the pre-existing moons and Triton. In particular, we expect early erosive impact(s) on Triton to generate debris that will, in subsequent collisions, disrupt the regular satellites. If the retrograde material were to dominate at some planetocentric distances, the end result may be a large cloud or disk of retrograde debris that would be accreted by Triton, shrinking Triton's orbit. Some of the prograde debris could survive in a compact disk interior to Triton's pericenter, eventually forming the inner moons of Neptune. We will present results of numerical modeling of these complex dynamical processes at the meeting.

  10. Creating a digital medical illustration.

    Science.gov (United States)

    Culley, Joanna

    2016-01-01

    This paper covers the steps required to complete a medical illustration in a digital format using Adobe Illustrator and Photoshop. The project example is the surgical procedure for the release of the glenohumeral joint for the condition known as 'frozen shoulder'. The purpose is to demonstrate one method which an artist can use within digital media to create a colour illustration such as the release of the glenohumeral joint. Included is a general overview as how to deal with the administration of a medical illustration commission through the experience of a professional freelance artist.

  11. Classical-quantal coupling in the capture of muons by hydrogen atoms

    International Nuclear Information System (INIS)

    Kwong, N.H.; Garcia, J.D.

    1989-01-01

    We describe a self-consistent semiclassical approach to the problem of muon capture by hydrogen atoms. The dynamics of the heavier muon and proton are treated classically, and the electron quantally, with the potentials for both being self-consistently determined. Our numerical results are compared to classical-trajectory Monte Carlo (CTMC) and adiabatic ionisation (AI) results. Our capture cross sections are larger at low energy but fall more rapidly to zero. Our results provide the corrections to the dynamics beyond the adiabatic picture, which were missing in other approaches; interesting questions concerning the quantal nature of the events are discussed. (author)

  12. Probabilistic numerics and uncertainty in computations.

    Science.gov (United States)

    Hennig, Philipp; Osborne, Michael A; Girolami, Mark

    2015-07-08

    We deliver a call to arms for probabilistic numerical methods : algorithms for numerical tasks, including linear algebra, integration, optimization and solving differential equations, that return uncertainties in their calculations. Such uncertainties, arising from the loss of precision induced by numerical calculation with limited time or hardware, are important for much contemporary science and industry. Within applications such as climate science and astrophysics, the need to make decisions on the basis of computations with large and complex data have led to a renewed focus on the management of numerical uncertainty. We describe how several seminal classic numerical methods can be interpreted naturally as probabilistic inference. We then show that the probabilistic view suggests new algorithms that can flexibly be adapted to suit application specifics, while delivering improved empirical performance. We provide concrete illustrations of the benefits of probabilistic numeric algorithms on real scientific problems from astrometry and astronomical imaging, while highlighting open problems with these new algorithms. Finally, we describe how probabilistic numerical methods provide a coherent framework for identifying the uncertainty in calculations performed with a combination of numerical algorithms (e.g. both numerical optimizers and differential equation solvers), potentially allowing the diagnosis (and control) of error sources in computations.

  13. On the Hughes model and numerical aspects

    KAUST Repository

    Gomes, Diogo A.

    2017-01-05

    We study a crowd model proposed by R. Hughes in [11] and we describe a numerical approach to solve it. This model comprises a Fokker-Planck equation coupled with an eikonal equation with Dirichlet or Neumann data. First, we establish a priori estimates for the solutions. Second, we study radial solutions and identify a shock formation mechanism. Third, we illustrate the existence of congestion, the breakdown of the model, and the trend to the equilibrium. Finally, we propose a new numerical method and consider two examples.

  14. Medical Illustration

    Science.gov (United States)

    ... as medical books, journals, magazines, pharma or biotech marketing, films, online video, exhibits, posters, wall charts, educational ... of the health career profession with strong communication skills, medical illustrators work closely with clients to interpret ...

  15. Some Numerical Aspects on Crowd Motion - The Hughes Model

    KAUST Repository

    Gomes, Diogo A.

    2016-01-06

    Here, we study a crowd model proposed by R. Hughes in [5] and we describe a numerical approach to solve it. This model comprises a Fokker-Planck equation coupled with an Eikonal equation with Dirichlet or Neumann data. First, we establish a priori estimates for the solution. Second, we study radial solutions and identify a shock formation mechanism. Third, we illustrate the existence of congestion, the breakdown of the model, and the trend to the equilibrium. Finally, we propose a new numerical method and consider two numerical examples.

  16. Illustrating answers: an evaluation of automatically retrieved illustrations of answers to medical questions

    NARCIS (Netherlands)

    Bosma, W.E.; Theune, Mariet; van Hooijdonk, C.M.J.; Krahmer, E.; Maes, F.

    In this paper we discuss and evaluate a method for automatic text illustration, applied to answers to medical questions. Our method for selecting illustrations is based on the idea that similarities between the answers and picture-related text (the picture’s caption or the section/paragraph that

  17. Mutual capture of dipolar molecules at low and very low energies. I. Approximate analytical treatment.

    Science.gov (United States)

    Nikitin, E E; Troe, J

    2010-09-16

    Approximate analytical expressions are derived for the low-energy rate coefficients of capture of two identical dipolar polarizable rigid rotors in their lowest nonresonant (j(1) = 0 and j(2) = 0) and resonant (j(1) = 0,1 and j(2) = 1,0) states. The considered range extends from the quantum, ultralow energy regime, characterized by s-wave capture, to the classical regime described within fly wheel and adiabatic channel approaches, respectively. This is illustrated by the table of contents graphic (available on the Web) that shows the scaled rate coefficients for the mutual capture of rotors in the resonant state versus the reduced wave vector between the Bethe zero-energy (left arrows) and classical high-energy (right arrow) limits for different ratios δ of the dipole-dipole to dispersion interaction.

  18. Numerical Solutions for Convection-Diffusion Equation through Non-Polynomial Spline

    Directory of Open Access Journals (Sweden)

    Ravi Kanth A.S.V.

    2016-01-01

    Full Text Available In this paper, numerical solutions for convection-diffusion equation via non-polynomial splines are studied. We purpose an implicit method based on non-polynomial spline functions for solving the convection-diffusion equation. The method is proven to be unconditionally stable by using Von Neumann technique. Numerical results are illustrated to demonstrate the efficiency and stability of the purposed method.

  19. Numerical Simulation of Polynomial-Speed Convergence Phenomenon

    Science.gov (United States)

    Li, Yao; Xu, Hui

    2017-11-01

    We provide a hybrid method that captures the polynomial speed of convergence and polynomial speed of mixing for Markov processes. The hybrid method that we introduce is based on the coupling technique and renewal theory. We propose to replace some estimates in classical results about the ergodicity of Markov processes by numerical simulations when the corresponding analytical proof is difficult. After that, all remaining conclusions can be derived from rigorous analysis. Then we apply our results to seek numerical justification for the ergodicity of two 1D microscopic heat conduction models. The mixing rate of these two models are expected to be polynomial but very difficult to prove. In both examples, our numerical results match the expected polynomial mixing rate well.

  20. Numerical study of interfacial flows with immersed solids

    International Nuclear Information System (INIS)

    Kim, Sung Il; Son, Gi Hun

    2003-01-01

    A numerical method is presented for computing unsteady incompressible two-phase flows with immersed solids. The method is based on a level set technique for capturing the phase interface, which is modified to satisfy a contact angle condition at the solid-fluid interface as well as to achieve mass conservation during the whole calculation procedure. The modified level set method is applied for numerical simulation of bubble deformation in a micro channel with a cylindrical solid block and liquid jet from a micro nozzle

  1. Examples of the nonlinear dynamics of ballistic capture and escape in the earth-moon system

    Science.gov (United States)

    Belbruno, Edward A.

    1990-01-01

    An example of a trajectory is given which is initially captured in an elliptic resonant orbit about the earth and then ballistically escapes the earth-moon system. This is demonstrated by a numerical example in three-dimensions using a planetary ephemeris. Another example shows a mechanism of how an elliptic orbit about the earth can increase its energy by performing a complex nonlinear transition to an elliptic orbit of a larger semi-major axis. Capture is also considered. An application of ballistic capture at the moon via an unstable periodic orbit using the four-body sun-earth-moon-S/C interaction is described.

  2. Radiology illustrated. Gastrointestinal tract

    International Nuclear Information System (INIS)

    Choi, Byung Ihn

    2015-01-01

    Radiology Illustrated: Gastrointestinal Tract is the second of two volumes designed to provide clear and practical guidance on the diagnostic imaging of abdominal diseases. The book presents approximately 300 cases with 1500 carefully selected and categorized illustrations of gastrointestinal tract diseases, along with key text messages and tables that will help the reader easily to recall the relevant images as an aid to differential diagnosis., Essential points are summarized at the end of each text message to facilitate rapid review and learning. Additionally, brief descriptions of each clinical problem are provided, followed by case studies of both common and uncommon pathologies that illustrate the roles of the different imaging modalities, including ultrasound, radiography, computed tomography, and magnetic resonance imaging.

  3. Radiology illustrated. Gastrointestinal tract

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Byung Ihn (ed.) [Seoul National University Hospital (Korea, Republic of). Dept. of Radiology

    2015-02-01

    Radiology Illustrated: Gastrointestinal Tract is the second of two volumes designed to provide clear and practical guidance on the diagnostic imaging of abdominal diseases. The book presents approximately 300 cases with 1500 carefully selected and categorized illustrations of gastrointestinal tract diseases, along with key text messages and tables that will help the reader easily to recall the relevant images as an aid to differential diagnosis., Essential points are summarized at the end of each text message to facilitate rapid review and learning. Additionally, brief descriptions of each clinical problem are provided, followed by case studies of both common and uncommon pathologies that illustrate the roles of the different imaging modalities, including ultrasound, radiography, computed tomography, and magnetic resonance imaging.

  4. Numerical methods in multibody dynamics

    CERN Document Server

    Eich-Soellner, Edda

    1998-01-01

    Today computers play an important role in the development of complex mechanical systems, such as cars, railway vehicles or machines. Efficient simulation of these systems is only possible when based on methods that explore the strong link between numerics and computational mechanics. This book gives insight into modern techniques of numerical mathematics in the light of an interesting field of applications: multibody dynamics. The important interaction between modeling and solution techniques is demonstrated by using a simplified multibody model of a truck. Different versions of this mechanical model illustrate all key concepts in static and dynamic analysis as well as in parameter identification. The book focuses in particular on constrained mechanical systems. Their formulation in terms of differential-algebraic equations is the backbone of nearly all chapters. The book is written for students and teachers in numerical analysis and mechanical engineering as well as for engineers in industrial research labor...

  5. Dust grain resonant capture: A statistical study

    Science.gov (United States)

    Marzari, F.; Vanzani, V.; Weidenschilling, S. J.

    1993-01-01

    A statistical approach, based on a large number of simultaneous numerical integrations, is adopted to study the capture in external mean motion resonances with the Earth of micron size dust grains perturbed by solar radiation and wind forces. We explore the dependence of the resonant capture phenomenon on the initial eccentricity e(sub 0) and perihelion argument w(sub 0) of the dust particle orbit. The intensity of both the resonant and dissipative (Poynting-Robertson and wind drag) perturbations strongly depends on the eccentricity of the particle while the perihelion argument determines, for low inclination, the mutual geometrical configuration of the particle's orbit with respect to the Earth's orbit. We present results for three j:j+1 commensurabilities (2:3, 4:5 and 6:7) and also for particle sizes s = 15, 30 microns. This study extends our previous work on the long term orbital evolution of single dust particles trapped into resonances with the Earth.

  6. Excitation of multiphase waves of the nonlinear Schroedinger equation by capture into resonances

    International Nuclear Information System (INIS)

    Friedland, L.; Shagalov, A.G.

    2005-01-01

    A method for adiabatic excitation and control of multiphase (N-band) waves of the periodic nonlinear Schroedinger (NLS) equation is developed. The approach is based on capturing the system into successive resonances with external, small amplitude plane waves having slowly varying frequencies. The excitation proceeds from zero and develops in stages, as an (N+1)-band (N=0,1,2,...), growing amplitude wave is formed in the (N+1)th stage from an N-band solution excited in the preceding stage. The method is illustrated in simulations, where the excited multiphase waves are analyzed via the spectral approach of the inverse scattering transform method. The theory of excitation of 0- and 1-band NLS solutions by capture into resonances is developed on the basis of a weakly nonlinear version of Whitham's averaged variational principle. The phenomenon of thresholds on the driving amplitudes for capture into successive resonances and the stability of driven, phase-locked solutions in these cases are discussed

  7. Local impact effects on concrete target due to missile: An empirical and numerical approach

    International Nuclear Information System (INIS)

    Ranjan, Rajiv; Banerjee, Sauvik; Singh, R.K.; Banerji, Pradipta

    2014-01-01

    Highlights: • Local impact effect of hard missile on reinforced concrete targets has been studied. • Review of empirical formulation for predicting local response carried out. • Numerical simulation of experimental test of Kojima (1991) carried out. • Divergence of FE results with those obtained using emperical formulations. • Close match of numerical simulation results with experimental data. - Abstract: Concrete containment walls and internal concrete barrier walls of a Nuclear Power Plant safety related structures are often required to be designed for externally and internally generated missiles. Potential missiles include external extreme wind generated missiles, aircraft crash and internal accident generated missiles such as impact due to turbine blade failure and steel pipe missiles resulting from pipe break. The objective of the present paper is to compare local missile impact effects on reinforced concrete target using available empirical formulations with those obtained using LS-DYNA numerical simulation. The use of numerical simulations for capturing the transient structural response has become increasingly used for structural design against impact loads. They overcome the limits of applicability of the empirical formulae and also provide information on stress and deformation fields, which may be used to improve the resistance of the concrete. Finite element (FE) analyses of an experimental impact problem reported by Kojima (1991) are carried out that are able to capture the missile impact effects; in terms of local and global damage. The continuous surface cap model has been used for modelling concrete behaviour. A range of missile velocity has been considered to simulate local missile impact phenomenon and modes of failure and to capture the concrete response from elastic to plastic fracture. A comparison is then made between the empirical formulations, numerical simulation results, and available experimental results of slab impact tests

  8. Monte Carlo based dosimetry and treatment planning for neutron capture therapy of brain tumors

    International Nuclear Information System (INIS)

    Zamenhof, R.G.; Clement, S.D.; Harling, O.K.; Brenner, J.F.; Wazer, D.E.; Madoc-Jones, H.; Yanch, J.C.

    1990-01-01

    Monte Carlo based dosimetry and computer-aided treatment planning for neutron capture therapy have been developed to provide the necessary link between physical dosimetric measurements performed on the MITR-II epithermal-neutron beams and the need of the radiation oncologist to synthesize large amounts of dosimetric data into a clinically meaningful treatment plan for each individual patient. Monte Carlo simulation has been employed to characterize the spatial dose distributions within a skull/brain model irradiated by an epithermal-neutron beam designed for neutron capture therapy applications. The geometry and elemental composition employed for the mathematical skull/brain model and the neutron and photon fluence-to-dose conversion formalism are presented. A treatment planning program, NCTPLAN, developed specifically for neutron capture therapy, is described. Examples are presented illustrating both one and two-dimensional dose distributions obtainable within the brain with an experimental epithermal-neutron beam, together with beam quality and treatment plan efficacy criteria which have been formulated for neutron capture therapy. The incorporation of three-dimensional computed tomographic image data into the treatment planning procedure is illustrated. The experimental epithermal-neutron beam has a maximum usable circular diameter of 20 cm, and with 30 ppm of B-10 in tumor and 3 ppm of B-10 in blood, it produces a beam-axis advantage depth of 7.4 cm, a beam-axis advantage ratio of 1.83, a global advantage ratio of 1.70, and an advantage depth RBE-dose rate to tumor of 20.6 RBE-cGy/min (cJ/kg-min). These characteristics make this beam well suited for clinical applications, enabling an RBE-dose of 2,000 RBE-cGy/min (cJ/kg-min) to be delivered to tumor at brain midline in six fractions with a treatment time of approximately 16 minutes per fraction

  9. Numerical method for two-phase flow discontinuity propagation calculation

    International Nuclear Information System (INIS)

    Toumi, I.; Raymond, P.

    1989-01-01

    In this paper, we present a class of numerical shock-capturing schemes for hyperbolic systems of conservation laws modelling two-phase flow. First, we solve the Riemann problem for a two-phase flow with unequal velocities. Then, we construct two approximate Riemann solvers: an one intermediate-state Riemann solver and a generalized Roe's approximate Riemann solver. We give some numerical results for one-dimensional shock-tube problems and for a standard two-phase flow heat addition problem involving two-phase flow instabilities

  10. Numerical Methods for a Class of Differential Algebraic Equations

    Directory of Open Access Journals (Sweden)

    Lei Ren

    2017-01-01

    Full Text Available This paper is devoted to the study of some efficient numerical methods for the differential algebraic equations (DAEs. At first, we propose a finite algorithm to compute the Drazin inverse of the time varying DAEs. Numerical experiments are presented by Drazin inverse and Radau IIA method, which illustrate that the precision of the Drazin inverse method is higher than the Radau IIA method. Then, Drazin inverse, Radau IIA, and Padé approximation are applied to the constant coefficient DAEs, respectively. Numerical results demonstrate that the Padé approximation is powerful for solving constant coefficient DAEs.

  11. Free-Flyer Capture - New Robotic Challenges from the International Space Station

    Science.gov (United States)

    Smith, C.; Seagram, J.

    The Japanese H-II Transfer Vehicle (HTV) will be the first free-flyer to visit the International Space Station (ISS) that will be captured by the Space Station Remote Manipulator System (SSRMS). Experience gained from the free-flyer captures completed previously by the Remote Manipulator System of the Space Shuttle has helped provide a foundation for the operational concept of capturing free-flyers. However, additional complications arise in the concept of free-flyer capture when carried out by the SSRMS from the ISS. Such issues include: ISS manoeuvrability and the difficulty of the ISS to quickly react to collision avoidance; current hardware and architecture design constraints of the SSRMS on-orbit; and HTV retreat and system limitations. This paper will discuss these issues and the numerous challenges they generate in trying to ensure that the safety of the ISS is maintained while trying to also guarantee the successful capture of the HTV; a vehicle containing potentially critical equipment and supplies for the ISS and its crew. As well, this paper will highlight the SSRMS system enhancements and innovative operational solutions that have enhanced the probability of mission success, and have been necessary to meet the failure tolerance and recovery requirements.

  12. 45 CFR 1170.13 - Illustrative examples.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Illustrative examples. 1170.13 Section 1170.13... ASSISTED PROGRAMS OR ACTIVITIES Discrimination Prohibited § 1170.13 Illustrative examples. (a) The following examples will illustrate the application of the foregoing provisions to some of the activities...

  13. Numerical models of groundwater flow and transport

    International Nuclear Information System (INIS)

    Konikow, L.F.

    1996-01-01

    This chapter reviews the state-of-the-art in deterministic modeling of groundwater flow and transport processes, which can be used for interpretation of isotope data through groundwater flow analyses. Numerical models which are available for this purpose are described and their applications to complex field problems are discussed. The theoretical bases of deterministic modeling are summarized, and advantages and limitations of numerical models are described. The selection of models for specific applications and their calibration procedures are described, and results of a few illustrative case study type applications are provided. (author). 145 refs, 17 figs, 2 tabs

  14. Numerical models of groundwater flow and transport

    Energy Technology Data Exchange (ETDEWEB)

    Konikow, L F [Geological Survey, Reston, VA (United States)

    1996-10-01

    This chapter reviews the state-of-the-art in deterministic modeling of groundwater flow and transport processes, which can be used for interpretation of isotope data through groundwater flow analyses. Numerical models which are available for this purpose are described and their applications to complex field problems are discussed. The theoretical bases of deterministic modeling are summarized, and advantages and limitations of numerical models are described. The selection of models for specific applications and their calibration procedures are described, and results of a few illustrative case study type applications are provided. (author). 145 refs, 17 figs, 2 tabs.

  15. Two numerical methods for mean-field games

    KAUST Repository

    Gomes, Diogo A.

    2016-01-01

    Here, we consider numerical methods for stationary mean-field games (MFG) and investigate two classes of algorithms. The first one is a gradient flow method based on the variational characterization of certain MFG. The second one uses monotonicity properties of MFG. We illustrate our methods with various examples, including one-dimensional periodic MFG, congestion problems, and higher-dimensional models.

  16. Two numerical methods for mean-field games

    KAUST Repository

    Gomes, Diogo A.

    2016-01-09

    Here, we consider numerical methods for stationary mean-field games (MFG) and investigate two classes of algorithms. The first one is a gradient flow method based on the variational characterization of certain MFG. The second one uses monotonicity properties of MFG. We illustrate our methods with various examples, including one-dimensional periodic MFG, congestion problems, and higher-dimensional models.

  17. Particle capture efficiency in a multi-wire model for high gradient magnetic separation

    KAUST Repository

    Eisenträger, Almut

    2014-07-21

    High gradient magnetic separation (HGMS) is an efficient way to remove magnetic and paramagnetic particles, such as heavy metals, from waste water. As the suspension flows through a magnetized filter mesh, high magnetic gradients around the wires attract and capture the particles removing them from the fluid. We model such a system by considering the motion of a paramagnetic tracer particle through a periodic array of magnetized cylinders. We show that there is a critical Mason number (ratio of viscous to magnetic forces) below which the particle is captured irrespective of its initial position in the array. Above this threshold, particle capture is only partially successful and depends on the particle\\'s entry position. We determine the relationship between the critical Mason number and the system geometry using numerical and asymptotic calculations. If a capture efficiency below 100% is sufficient, our results demonstrate how operating the HGMS system above the critical Mason number but with multiple separation cycles may increase efficiency. © 2014 AIP Publishing LLC.

  18. The numerical simulation of accelerator components

    International Nuclear Information System (INIS)

    Herrmannsfeldt, W.B.; Hanerfeld, H.

    1987-05-01

    The techniques of the numerical simulation of plasmas can be readily applied to problems in accelerator physics. Because the problems usually involve a single component ''plasma,'' and times that are at most, a few plasma oscillation periods, it is frequently possible to make very good simulations with relatively modest computation resources. We will discuss the methods and illustrate them with several examples. One of the more powerful techniques of understanding the motion of charged particles is to view computer-generated motion pictures. We will show several little movie strips to illustrate the discussions. The examples will be drawn from the application areas of Heavy Ion Fusion, electron-positron linear colliders and injectors for free-electron lasers. 13 refs., 10 figs., 2 tabs

  19. Post-capture vibration suppression of spacecraft via a bio-inspired isolation system

    Science.gov (United States)

    Dai, Honghua; Jing, Xingjian; Wang, Yu; Yue, Xiaokui; Yuan, Jianping

    2018-05-01

    Inspired by the smooth motions of a running kangaroo, a bio-inspired quadrilateral shape (BIQS) structure is proposed to suppress the vibrations of a free-floating spacecraft subject to periodic or impulsive forces, which may be encountered during on-orbit servicing missions. In particular, the BIQS structure is installed between the satellite platform and the capture mechanism. The dynamical model of the BIQS isolation system, i.e. a BIQS structure connecting the platform and the capture mechanism at each side, is established by Lagrange's equations to simulate the post-capture dynamical responses. The BIQS system suffering an impulsive force is dealt with by means of a modified version of Lagrange's equations. Furthermore, the classical harmonic balance method is used to solve the nonlinear dynamical system subject to periodic forces, while for the case under impulsive forces the numerical integration method is adopted. Due to the weightless environment in space, the present BIQS system is essentially an under-constrained dynamical system with one of its natural frequencies being identical to zero. The effects of system parameters, such as the number of layers in BIQS, stiffness, assembly angle, rod length, damping coefficient, masses of satellite platform and capture mechanism, on the isolation performance of the present system are thoroughly investigated. In addition, comparisons between the isolation performances of the presently proposed BIQS isolator and the conventional spring-mass-damper (SMD) isolator are conducted to demonstrate the advantages of the present isolator. Numerical simulations show that the BIQS system has a much better performance than the SMD system under either periodic or impulsive forces. Overall, the present BIQS isolator offers a highly efficient passive way for vibration suppressions of free-floating spacecraft.

  20. Numerical prediction of green water loads on ships

    DEFF Research Database (Denmark)

    Nielsen, Kristian Bendix

    2003-01-01

    The main objective of the present study has been to investigate problems related to shipping green water on deck of a floating vessel by use of numerical methods. A Navier-Stokes solver with a free surface capturing scheme, similar to the VOF method (Hirt and Nichols, 1981) has been applied...... green water problem with relative ship motion included. Great effoort has been made to validate and verify the numerical method and all computations have been verified by use of several computational grids with increasing resolution and validated by comparison to experimental data. Results from the dam...

  1. Exact solutions, numerical relativity and gravitational radiation

    International Nuclear Information System (INIS)

    Winicour, J.

    1986-01-01

    In recent years, there has emerged a new use for exact solutions to Einstein's equation as checks on the accuracy of numerical relativity codes. Much has already been written about codes based upon the space-like Cauchy problem. In the case of two Killing vectors, a numerical characteristic initial value formulation based upon two intersecting families of null hypersurfaces has successfully evolved the Schwarzschild and the colliding plane wave vacuum solutions. Here the author discusses, in the context of exact solutions, numerical studies of gravitational radiation based upon the null cone initial value problem. Every stage of progress in the null cone approach has been associated with exact solutions in some sense. He begins by briefly recapping this history. Then he presents two new examples illustrating how exact solutions can be useful

  2. An efficient shock-capturing scheme for simulating compressible homogeneous mixture flow

    Energy Technology Data Exchange (ETDEWEB)

    Dang, Son Tung; Ha, Cong Tu; Park, Warn Gyu [School of Mechanical Engineering, Pusan National University, Busan (Korea, Republic of); Jung, Chul Min [Advanced Naval Technology CenterNSRDI, ADD, Changwon (Korea, Republic of)

    2016-09-15

    This work is devoted to the development of a procedure for the numerical solution of Navier-Stokes equations for cavitating flows with and without ventilation based on a compressible, multiphase, homogeneous mixture model. The governing equations are discretized on a general structured grid using a high-resolution shock-capturing scheme in conjunction with appropriate limiters to prevent the generation of spurious solutions near shock waves or discontinuities. Two well-known limiters are examined, and a new limiter is proposed to enhance the accuracy and stability of the numerical scheme. A sensitivity analysis is first conducted to determine the relative influences of various model parameters on the solution. These parameters are adopted for the computation of water flows over a hemispherical body, conical body and a divergent/convergent nozzle. Finally, numerical calculations of ventilated supercavitating flows over a hemispherical cylinder body with a hot propulsive jet are conducted to verify the capabilities of the numerical scheme.

  3. An efficient shock-capturing scheme for simulating compressible homogeneous mixture flow

    International Nuclear Information System (INIS)

    Dang, Son Tung; Ha, Cong Tu; Park, Warn Gyu; Jung, Chul Min

    2016-01-01

    This work is devoted to the development of a procedure for the numerical solution of Navier-Stokes equations for cavitating flows with and without ventilation based on a compressible, multiphase, homogeneous mixture model. The governing equations are discretized on a general structured grid using a high-resolution shock-capturing scheme in conjunction with appropriate limiters to prevent the generation of spurious solutions near shock waves or discontinuities. Two well-known limiters are examined, and a new limiter is proposed to enhance the accuracy and stability of the numerical scheme. A sensitivity analysis is first conducted to determine the relative influences of various model parameters on the solution. These parameters are adopted for the computation of water flows over a hemispherical body, conical body and a divergent/convergent nozzle. Finally, numerical calculations of ventilated supercavitating flows over a hemispherical cylinder body with a hot propulsive jet are conducted to verify the capabilities of the numerical scheme

  4. Numerical Modeling of Ablation Heat Transfer

    Science.gov (United States)

    Ewing, Mark E.; Laker, Travis S.; Walker, David T.

    2013-01-01

    A unique numerical method has been developed for solving one-dimensional ablation heat transfer problems. This paper provides a comprehensive description of the method, along with detailed derivations of the governing equations. This methodology supports solutions for traditional ablation modeling including such effects as heat transfer, material decomposition, pyrolysis gas permeation and heat exchange, and thermochemical surface erosion. The numerical scheme utilizes a control-volume approach with a variable grid to account for surface movement. This method directly supports implementation of nontraditional models such as material swelling and mechanical erosion, extending capabilities for modeling complex ablation phenomena. Verifications of the numerical implementation are provided using analytical solutions, code comparisons, and the method of manufactured solutions. These verifications are used to demonstrate solution accuracy and proper error convergence rates. A simple demonstration of a mechanical erosion (spallation) model is also provided to illustrate the unique capabilities of the method.

  5. An intelligent system for monitoring and diagnosis of the CO{sub 2} capture process

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Q.; Chan, C.W.; Tontiwachwuthikul, P. [University of Regina, Regina, SK (Canada). Faculty of Engineering

    2011-07-15

    Amine-based carbon dioxide capture has been widely considered as a feasible ideal technology for reducing large-scale CO{sub 2} emissions and mitigating global warming. The operation of amine-based CO{sub 2} capture is a complicated task, which involves monitoring over 100 process parameters and careful manipulation of numerous valves and pumps. The current research in the field of CO{sub 2} capture has emphasized the need for improving CO{sub 2} capture efficiency and enhancing plant performance. In the present study, artificial intelligence techniques were applied for developing a knowledge-based expert system that aims at effectively monitoring and controlling the CO{sub 2} capture process and thereby enhancing CO{sub 2} capture efficiency. In developing the system, the inferential modeling technique (IMT) was applied to analyze the domain knowledge and problem-solving techniques, and a knowledge base was developed on DeltaV Simulate. The expert system helps to enhance CO{sub 2} capture system performance and efficiency by reducing the time required for diagnosis and problem solving if abnormal conditions occur. The expert system can be used as a decision-support tool that helps inexperienced operators control the plant: it can be used also for training novice operators.

  6. A numerical methodology for the Painlevé equations

    KAUST Repository

    Fornberg, Bengt

    2011-07-01

    The six Painlevé transcendents PI-PVI have both applications and analytic properties that make them stand out from most other classes of special functions. Although they have been the subject of extensive theoretical investigations for about a century, they still have a reputation for being numerically challenging. In particular, their extensive pole fields in the complex plane have often been perceived as \\'numerical mine fields\\'. In the present work, we note that the Painlevé property in fact provides the opportunity for very fast and accurate numerical solutions throughout such fields. When combining a Taylor/Padé-based ODE initial value solver for the pole fields with a boundary value solver for smooth regions, numerical solutions become available across the full complex plane. We focus here on the numerical methodology, and illustrate it for the PI equation. In later studies, we will concentrate on mathematical aspects of both the PI and the higher Painlevé transcendents. © 2011 Elsevier Inc.

  7. The pdk-100 enhances interpretation capabilities for pulsed neutron capture logs

    International Nuclear Information System (INIS)

    Randall, R.R.; Oliver, D.W.; Ferti, W.H.

    1986-01-01

    The PDK-100 is a new pulsed neutron logging system designed to measure Sigma (Σ), the macroscopic thermal neutron capture cross section. In addition to determining Σ, the system provides logging curves which are a measure of formation porosity and which furnish information concerning borehole conditions. This paper reviews the principles of operation of the PDK-100, and presents examples which illustrate the utility of the logging system. In addition, the progress of investigations into new parameters which can be derived with pulsed neutron logging data will be reported

  8. Hydrodynamic Capture and Release of Passively Driven Particles by Active Particles Under Hele-Shaw Flows

    Science.gov (United States)

    Mishler, Grant; Tsang, Alan Cheng Hou; Pak, On Shun

    2018-03-01

    The transport of active and passive particles plays central roles in diverse biological phenomena and engineering applications. In this paper, we present a theoretical investigation of a system consisting of an active particle and a passive particle in a confined micro-fluidic flow. The introduction of an external flow is found to induce the capture of the passive particle by the active particle via long-range hydrodynamic interactions among the particles. This hydrodynamic capture mechanism relies on an attracting stable equilibrium configuration formed by the particles, which occurs when the external flow intensity exceeds a certain threshold. We evaluate this threshold by studying the stability of the equilibrium configurations analytically and numerically. Furthermore, we study the dynamics of typical capture and non-capture events and characterize the basins of attraction of the equilibrium configurations. Our findings reveal a critical dependence of the hydrodynamic capture mechanism on the external flow intensity. Through adjusting the external flow intensity across the stability threshold, we demonstrate that the active particle can capture and release the passive particle in a controllable manner. Such a capture-and-release mechanism is desirable for biomedical applications such as the capture and release of therapeutic payloads by synthetic micro-swimmers in targeted drug delivery.

  9. Commonwealth Edison captures intruders on screen

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Commonwealth Edison has developed three software programs, with the supporting hardware, that significantly upgrade security monitoring capabilities at nuclear power stations. These are Video Capture, the Alternate Perimeter Alarm Reporting System, and the Redundant Access Control System. Conventional video systems only display what is happening at the moment and rewinding a VCR to discover what occurred earlier takes time. With Video Capture the images can be instantly restored to the monitor screen and printed out. When one of the security devices used to monitor the perimeter of a Commonwealth Edison nuclear power station is tripped, the Video Capture program stores the visual image digitally. This is done using similar technology to the employed in fax machines. The security staff are thus able to distinguish immediately between disturbances taking place simultaneously at different security zones. They can magnify and compare the stored images and print them out. The Alternate Perimeter Alarm Reporting System was developed to speed the transmission of alarm signals from the security sensors to the security computer. The Redundant Access Control System (RACS) was originally developed to meet the requirement of the Nuclear Regulatory Commission (NRC) for a secondary computer-operated security measure to monitor employee access to a nuclear power station. When employee drug testing became an additional NRC requirement, the Nuclear Division of Commonwealth Edison asked their programmers to modify RACS to generate a random list of personnel to be tested for substance abuse. RACS was then further modified to produce numerous station operating reports that had been previously compiled manually. (author)

  10. A new capture fraction method to map how pumpage affects surface water flow

    Science.gov (United States)

    Leake, S.A.; Reeves, H.W.; Dickinson, J.E.

    2010-01-01

    All groundwater pumped is balanced by removal of water somewhere, initially from storage in the aquifer and later from capture in the form of increase in recharge and decrease in discharge. Capture that results in a loss of water in streams, rivers, and wetlands now is a concern in many parts of the United States. Hydrologists commonly use analytical and numerical approaches to study temporal variations in sources of water to wells for select points of interest. Much can be learned about coupled surface/groundwater systems, however, by looking at the spatial distribution of theoretical capture for select times of interest. Development of maps of capture requires (1) a reasonably well-constructed transient or steady state model of an aquifer with head-dependent flow boundaries representing surface water features or evapotranspiration and (2) an automated procedure to run the model repeatedly and extract results, each time with a well in a different location. This paper presents new methods for simulating and mapping capture using three-dimensional groundwater flow models and presents examples from Arizona, Oregon, and Michigan. Journal compilation ?? 2010 National Ground Water Association. No claim to original US government works.

  11. Optional carbon capture

    Energy Technology Data Exchange (ETDEWEB)

    Alderson, T.; Scott, S.; Griffiths, J. [Jacobs Engineering, London (United Kingdom)

    2007-07-01

    In the case of IGCC power plants, carbon capture can be carried out before combustion. The carbon monoxide in the syngas is catalytically shifted to carbon dioxide and then captured in a standard gas absorption system. However, the insertion of a shift converter into an existing IGCC plant with no shift would mean a near total rebuild of the gasification waste heat recovery, gas treatment system and HRSG, with only the gasifier and gas turbine retaining most of their original features. To reduce the extent, cost and time taken for the revamping, the original plant could incorporate the shift, and the plant would then be operated without capture to advantage, and converted to capture mode of operation when commercially appropriate. This paper examines this concept of placing a shift converter into an IGCC plant before capture is required, and operating the same plant first without and then later with CO{sub 2} capture in a European context. The advantages and disadvantages of this 'capture ready' option are discussed. 6 refs., 2 figs., 4 tabs.

  12. Monotone numerical methods for finite-state mean-field games

    KAUST Repository

    Gomes, Diogo A.; Saude, Joao

    2017-01-01

    Here, we develop numerical methods for finite-state mean-field games (MFGs) that satisfy a monotonicity condition. MFGs are determined by a system of differential equations with initial and terminal boundary conditions. These non-standard conditions are the main difficulty in the numerical approximation of solutions. Using the monotonicity condition, we build a flow that is a contraction and whose fixed points solve the MFG, both for stationary and time-dependent problems. We illustrate our methods in a MFG modeling the paradigm-shift problem.

  13. Monotone numerical methods for finite-state mean-field games

    KAUST Repository

    Gomes, Diogo A.

    2017-04-29

    Here, we develop numerical methods for finite-state mean-field games (MFGs) that satisfy a monotonicity condition. MFGs are determined by a system of differential equations with initial and terminal boundary conditions. These non-standard conditions are the main difficulty in the numerical approximation of solutions. Using the monotonicity condition, we build a flow that is a contraction and whose fixed points solve the MFG, both for stationary and time-dependent problems. We illustrate our methods in a MFG modeling the paradigm-shift problem.

  14. Numerical methods for semiconductor heterostructures with band nonparabolicity

    International Nuclear Information System (INIS)

    Wang Weichung; Hwang Tsungmin; Lin Wenwei; Liu Jinnliang

    2003-01-01

    This article presents numerical methods for computing bound state energies and associated wave functions of three-dimensional semiconductor heterostructures with special interest in the numerical treatment of the effect of band nonparabolicity. A nonuniform finite difference method is presented to approximate a model of a cylindrical-shaped semiconductor quantum dot embedded in another semiconductor matrix. A matrix reduction method is then proposed to dramatically reduce huge eigenvalue systems to relatively very small subsystems. Moreover, the nonparabolic band structure results in a cubic type of nonlinear eigenvalue problems for which a cubic Jacobi-Davidson method with an explicit nonequivalence deflation method are proposed to compute all the desired eigenpairs. Numerical results are given to illustrate the spectrum of energy levels and the corresponding wave functions in rather detail

  15. A simple, robust and efficient high-order accurate shock-capturing scheme for compressible flows: Towards minimalism

    Science.gov (United States)

    Ohwada, Taku; Shibata, Yuki; Kato, Takuma; Nakamura, Taichi

    2018-06-01

    Developed is a high-order accurate shock-capturing scheme for the compressible Euler/Navier-Stokes equations; the formal accuracy is 5th order in space and 4th order in time. The performance and efficiency of the scheme are validated in various numerical tests. The main ingredients of the scheme are nothing special; they are variants of the standard numerical flux, MUSCL, the usual Lagrange's polynomial and the conventional Runge-Kutta method. The scheme can compute a boundary layer accurately with a rational resolution and capture a stationary contact discontinuity sharply without inner points. And yet it is endowed with high resistance against shock anomalies (carbuncle phenomenon, post-shock oscillations, etc.). A good balance between high robustness and low dissipation is achieved by blending three types of numerical fluxes according to physical situation in an intuitively easy-to-understand way. The performance of the scheme is largely comparable to that of WENO5-Rusanov, while its computational cost is 30-40% less than of that of the advanced scheme.

  16. Numerical Simulation of Fluid Flow in a Simple Rotor/Stator Pair

    Science.gov (United States)

    1991-06-01

    describes a series of numerical experiments dealing with rotor/stator interactions in hydroturbines . The means of analysis was a nonconforming sliding...science and industry is the improvement of the efficiency of the hydroturbine . Numerical flow analysis is essential in order to properly conduct this...evaluation. The hydroturbine is typically modeled as an infinite series of rotor/stator pairs. Figure 1 is an illustration of an axial-flow machine with

  17. Numerical solutions of multi-order fractional differential equations by Boubaker polynomials

    Directory of Open Access Journals (Sweden)

    Bolandtalat A.

    2016-01-01

    Full Text Available In this paper, we have applied a numerical method based on Boubaker polynomials to obtain approximate numerical solutions of multi-order fractional differential equations. We obtain an operational matrix of fractional integration based on Boubaker polynomials. Using this operational matrix, the given problem is converted into a set of algebraic equations. Illustrative examples are are given to demonstrate the efficiency and simplicity of this technique.

  18. Gravitational capture

    International Nuclear Information System (INIS)

    Bondi, H.

    1979-01-01

    In spite of the strength of gravitational focres between celestial bodies, gravitational capture is not a simple concept. The principles of conservation of linear momentum and of conservation of angular momentum, always impose severe constraints, while conservation of energy and the vital distinction between dissipative and non-dissipative systems allows one to rule out capture in a wide variety of cases. In complex systems especially those without dissipation, long dwell time is a more significant concept than permanent capture. (author)

  19. Gas hydrate formation process for pre-combustion capture of carbon dioxide

    International Nuclear Information System (INIS)

    Lee, Hyun Ju; Lee, Ju Dong; Linga, Praveen; Englezos, Peter; Kim, Young Seok; Lee, Man Sig; Kim, Yang Do

    2010-01-01

    In this study, gas hydrate from CO 2 /H 2 gas mixtures with the addition of tetrahydrofuran (THF) was formed in a semi-batch stirred vessel at various pressures and temperatures to investigate the CO 2 separation/recovery properties. This mixture is of interest to CO 2 separation and recovery from Integrated Gasification Combine Cycle (IGCC) power plants. During hydrate formation the gas uptake was determined and composition changes in the gas phase were obtained by gas chromatography. The impact of THF on hydrate formation from the CO 2 /H 2 was observed. The addition of THF significantly reduced the equilibrium formation conditions. 1.0 mol% THF was found to be the optimum concentration for CO 2 capture based on kinetic experiments. The present study illustrates the concept and provides thermodynamic and kinetic data for the separation/recovery of CO 2 (pre-combustion capture) from a fuel gas (CO 2 /H 2 ) mixture.

  20. Capture ready study

    Energy Technology Data Exchange (ETDEWEB)

    Minchener, A.

    2007-07-15

    There are a large number of ways in which the capture of carbon as carbon dioxide (CO{sub 2}) can be integrated into fossil fuel power stations, most being applicable for both gas and coal feedstocks. To add to the choice of technology is the question of whether an existing plant should be retrofitted for capture, or whether it is more attractive to build totally new. This miscellany of choices adds considerably to the commercial risk of investing in a large power station. An intermediate stage between the non-capture and full capture state would be advantageous in helping to determine the best way forward and hence reduce those risks. In recent years the term 'carbon capture ready' or 'capture ready' has been coined to describe such an intermediate stage plant and is now widely used. However a detailed and all-encompassing definition of this term has never been published. All fossil fuel consuming plant produce a carbon dioxide gas byproduct. There is a possibility of scrubbing it with an appropriate CO{sub 2} solvent. Hence it could be said that all fossil fuel plant is in a condition for removal of its CO{sub 2} effluent and therefore already in a 'capture ready' state. Evidently, the practical reality of solvent scrubbing could cost more than the rewards offered by such as the ETS (European Trading Scheme). In which case, it can be said that although the possibility exists of capturing CO{sub 2}, it is not a commercially viable option and therefore the plant could not be described as ready for CO{sub 2} capture. The boundary between a capture ready and a non-capture ready condition using this definition cannot be determined in an objective and therefore universally acceptable way and criteria must be found which are less onerous and less potentially contentious to assess. 16 refs., 2 annexes.

  1. Molded underfill (MUF) encapsulation for flip-chip package: A numerical investigation

    Science.gov (United States)

    Azmi, M. A.; Abdullah, M. K.; Abdullah, M. Z.; Ariff, Z. M.; Saad, Abdullah Aziz; Hamid, M. F.; Ismail, M. A.

    2017-07-01

    This paper presents the numerical simulation of epoxy molding compound (EMC) filling in multi flip-chip packages during encapsulation process. The empty and a group flip chip packages were considered in the mold cavity in order to study the flow profile of the EMC. SOLIDWORKS software was used for three-dimensional modeling and it was incorporated into fluid analysis software namely as ANSYS FLUENT. The volume of fluid (VOF) technique was used for capturing the flow front profiles and Power Law model was applied for its rheology model. The numerical result are compared and discussed with previous experimental and it was shown a good conformity for model validation. The prediction of flow front was observed and analyzed at different filling time. The possibility and visual of void formation in the package is captured and the number of flip-chip is one factor that contributed to the void formation.

  2. Two Numerical Approaches to Stationary Mean-Field Games

    KAUST Repository

    Almulla, Noha; Ferreira, Rita; Gomes, Diogo A.

    2016-01-01

    Here, we consider numerical methods for stationary mean-field games (MFG) and investigate two classes of algorithms. The first one is a gradient-flow method based on the variational characterization of certain MFG. The second one uses monotonicity properties of MFG. We illustrate our methods with various examples, including one-dimensional periodic MFG, congestion problems, and higher-dimensional models.

  3. Two Numerical Approaches to Stationary Mean-Field Games

    KAUST Repository

    Almulla, Noha

    2016-10-04

    Here, we consider numerical methods for stationary mean-field games (MFG) and investigate two classes of algorithms. The first one is a gradient-flow method based on the variational characterization of certain MFG. The second one uses monotonicity properties of MFG. We illustrate our methods with various examples, including one-dimensional periodic MFG, congestion problems, and higher-dimensional models.

  4. Towards standard testbeds for numerical relativity

    International Nuclear Information System (INIS)

    Alcubierre, Miguel; Allen, Gabrielle; Bona, Carles; Fiske, David; Goodale, Tom; Guzman, F Siddhartha; Hawke, Ian; Hawley, Scott H; Husa, Sascha; Koppitz, Michael; Lechner, Christiane; Pollney, Denis; Rideout, David; Salgado, Marcelo; Schnetter, Erik; Seidel, Edward; Shinkai, Hisa-aki; Shoemaker, Deirdre; Szilagyi, Bela; Takahashi, Ryoji; Winicour, Jeff

    2004-01-01

    In recent years, many different numerical evolution schemes for Einstein's equations have been proposed to address stability and accuracy problems that have plagued the numerical relativity community for decades. Some of these approaches have been tested on different spacetimes, and conclusions have been drawn based on these tests. However, differences in results originate from many sources, including not only formulations of the equations, but also gauges, boundary conditions, numerical methods and so on. We propose to build up a suite of standardized testbeds for comparing approaches to the numerical evolution of Einstein's equations that are designed to both probe their strengths and weaknesses and to separate out different effects, and their causes, seen in the results. We discuss general design principles of suitable testbeds, and we present an initial round of simple tests with periodic boundary conditions. This is a pivotal first step towards building a suite of testbeds to serve the numerical relativists and researchers from related fields who wish to assess the capabilities of numerical relativity codes. We present some examples of how these tests can be quite effective in revealing various limitations of different approaches, and illustrating their differences. The tests are presently limited to vacuum spacetimes, can be run on modest computational resources and can be used with many different approaches used in the relativity community

  5. Towards standard testbeds for numerical relativity

    Energy Technology Data Exchange (ETDEWEB)

    Alcubierre, Miguel [Inst. de Ciencias Nucleares, Univ. Nacional Autonoma de Mexico, Apartado Postal 70-543, Mexico Distrito Federal 04510 (Mexico); Allen, Gabrielle; Goodale, Tom; Guzman, F Siddhartha; Hawke, Ian; Husa, Sascha; Koppitz, Michael; Lechner, Christiane; Pollney, Denis; Rideout, David [Max-Planck-Inst. fuer Gravitationsphysik, Albert-Einstein-Institut, 14476 Golm (Germany); Bona, Carles [Departament de Fisica, Universitat de les Illes Balears, Ctra de Valldemossa km 7.5, 07122 Palma de Mallorca (Spain); Fiske, David [Dept. of Physics, Univ. of Maryland, College Park, MD 20742-4111 (United States); Hawley, Scott H [Center for Relativity, Univ. of Texas at Austin, Austin, Texas 78712 (United States); Salgado, Marcelo [Inst. de Ciencias Nucleares, Univ. Nacional Autonoma de Mexico, Apartado Postal 70-543, Mexico Distrito Federal 04510 (Mexico); Schnetter, Erik [Inst. fuer Astronomie und Astrophysik, Universitaet Tuebingen, 72076 Tuebingen (Germany); Seidel, Edward [Max-Planck-Inst. fuer Gravitationsphysik, Albert-Einstein-Inst., 14476 Golm (Germany); Shinkai, Hisa-aki [Computational Science Div., Inst. of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Shoemaker, Deirdre [Center for Radiophysics and Space Research, Cornell Univ., Ithaca, NY 14853 (United States); Szilagyi, Bela [Dept. of Physics and Astronomy, Univ. of Pittsburgh, Pittsburgh, PA 15260 (United States); Takahashi, Ryoji [Theoretical Astrophysics Center, Juliane Maries Vej 30, 2100 Copenhagen, (Denmark); Winicour, Jeff [Max-Planck-Inst. fuer Gravitationsphysik, Albert-Einstein-Institut, 14476 Golm (Germany)

    2004-01-21

    In recent years, many different numerical evolution schemes for Einstein's equations have been proposed to address stability and accuracy problems that have plagued the numerical relativity community for decades. Some of these approaches have been tested on different spacetimes, and conclusions have been drawn based on these tests. However, differences in results originate from many sources, including not only formulations of the equations, but also gauges, boundary conditions, numerical methods and so on. We propose to build up a suite of standardized testbeds for comparing approaches to the numerical evolution of Einstein's equations that are designed to both probe their strengths and weaknesses and to separate out different effects, and their causes, seen in the results. We discuss general design principles of suitable testbeds, and we present an initial round of simple tests with periodic boundary conditions. This is a pivotal first step towards building a suite of testbeds to serve the numerical relativists and researchers from related fields who wish to assess the capabilities of numerical relativity codes. We present some examples of how these tests can be quite effective in revealing various limitations of different approaches, and illustrating their differences. The tests are presently limited to vacuum spacetimes, can be run on modest computational resources and can be used with many different approaches used in the relativity community.

  6. Capturing near-Earth asteroids around Earth

    Science.gov (United States)

    Hasnain, Zaki; Lamb, Christopher A.; Ross, Shane D.

    2012-12-01

    numerically calculated trajectories, 23 asteroids are recommended for future consideration for capture missions, provided necessary technological developments are made.

  7. Professional representation and the free-lance medical illustrator.

    Science.gov (United States)

    Mount, K N; Daugherty, J

    1994-01-01

    We researched factors related to the success or failure in working relationships between free-lance medical illustrators and artist's representatives. In the fall of 1992, surveys were mailed to 230 medical illustrators; 105 (46%) completed surveys were returned. Respondents were divided into three categories: 1) medical illustrators currently represented, 2) medical illustrators previously represented, and 3) medical illustrators who had never been represented. Comparisons made among illustrators from the three groups included business practices, clientele, experience, and self-promotion techniques. These comparisons revealed notable differences and similarities between the three groups and were subsequently analyzed to identify the characteristics of medical illustrators who would benefit from professional representation.

  8. Numerical methods for image registration

    CERN Document Server

    Modersitzki, Jan

    2003-01-01

    Based on the author's lecture notes and research, this well-illustrated and comprehensive text is one of the first to provide an introduction to image registration with particular emphasis on numerical methods in medical imaging. Ideal for researchers in industry and academia, it is also a suitable study guide for graduate mathematicians, computer scientists, engineers, medical physicists, and radiologists.Image registration is utilised whenever information obtained from different viewpoints needs to be combined or compared and unwanted distortion needs to be eliminated. For example, CCTV imag

  9. New Adsorption Cycles for Carbon Dioxide Capture and Concentration

    Energy Technology Data Exchange (ETDEWEB)

    James Ritter; Armin Ebner; Steven Reynolds Hai Du; Amal Mehrotra

    2008-07-31

    The objective of this three-year project was to study new pressure swing adsorption (PSA) cycles for CO{sub 2} capture and concentration at high temperature. The heavy reflux (HR) PSA concept and the use of a hydrotalcite like (HTlc) adsorbent that captures CO{sub 2} reversibly at high temperatures simply by changing the pressure were two key features of these new PSA cycles. Through the completion or initiation of nine tasks, a bench-scale experimental and theoretical program has been carried out to complement and extend the process simulation study that was carried out during Phase I (DE-FG26-03NT41799). This final report covers the entire project from August 1, 2005 to July 31, 2008. This program included the study of PSA cycles for CO{sub 2} capture by both rigorous numerical simulation and equilibrium theory analysis. The insight gained from these studies was invaluable toward the applicability of PSA for CO{sub 2} capture, whether done at ambient or high temperature. The rigorous numerical simulation studies showed that it is indeed possible to capture and concentrate CO{sub 2} by PSA. Over a wide range of conditions it was possible to achieve greater than 90% CO{sub 2} purity and/or greater than 90% CO{sub 2} recovery, depending on the particular heavy reflux (HR) PSA cycle under consideration. Three HR PSA cycles were identified as viable candidates for further study experimentally. The equilibrium theory analysis, which represents the upper thermodynamic limit of the performance of PSA process, further validated the use of certain HR PSA cycles for CO{sub 2} capture and concentration. A new graphical approach for complex PSA cycle scheduling was also developed during the course of this program. This new methodology involves a priori specifying the cycle steps, their sequence, and the number of beds, and then following a systematic procedure that requires filling in a 2-D grid based on a few simple rules, some heuristics and some experience. It has been

  10. Simulations of magnetic capturing of drug carriers in the brain vascular system

    Energy Technology Data Exchange (ETDEWEB)

    Kenjeres, S., E-mail: S.Kenjeres@tudelft.nl [Department of Multi-Scale Physics, Faculty of Applied Sciences, J.M. Burgerscentre for Fluid Dynamics, Delft University of Technology, Leeghwaterstraat 39, 2628 CB Delft (Netherlands); Righolt, B.W. [Department of Multi-Scale Physics, Faculty of Applied Sciences, J.M. Burgerscentre for Fluid Dynamics, Delft University of Technology, Leeghwaterstraat 39, 2628 CB Delft (Netherlands)

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer Blood flow and magnetic particles distributions in the brain vascular system simulated. Black-Right-Pointing-Pointer Numerical mesh generated from raw MRI images. Black-Right-Pointing-Pointer Significant increase in local capturing of magnetic particles obtained. Black-Right-Pointing-Pointer Promising technique for localised non-invasive treatment of brain tumours. - Abstract: The present paper reports on numerical simulations of blood flow and magnetic drug carrier distributions in a complex brain vascular system. The blood is represented as a non-Newtonian fluid by the generalised power law. The Lagrangian tracking of the double-layer spherical particles is performed to estimate particle deposition under influence of imposed magnetic field gradients across arterial walls. Two situations are considered: neutral (magnetic field off) and active control (magnetic field on) case. The double-layer spherical particles that mimic a real medical drug are characterised by two characteristic diameters - the outer one and the inner one of the magnetic core. A numerical mesh of the brain vascular system consisting of multi-branching arteries is generated from raw MRI scan images of a patient. The blood is supplied through four main inlet arteries and the entire vascular system includes more than 30 outlets, which are modelled by Murray's law. The no-slip boundary condition is applied for velocity components along the smooth and rigid arterial walls. Numerical simulations revealed detailed insights into blood flow patterns, wall-shear-stress and local particle deposition efficiency along arterial walls. It is demonstrated that magnetically targeted drug delivery significantly increased the particle capturing efficiency in the pre-defined regions. This feature can be potentially useful for localised, non-invasive treatment of brain tumours.

  11. Development of advanced sensing system for antipersonnel mines with neutron capture gamma-ray analysis

    International Nuclear Information System (INIS)

    Iguchi, Tetsuo

    2006-01-01

    Neutron induced prompt gamma-ray analysis (NPGA) for survey of antipersonnel landmines is developed. A concept of sensor system with compact strong accelerator neutron source, simulation of detection and simulation results by trial examinations are stated. The measurement principles, objects, system construction, development of compact accelerator neutron source and high performance neutron capture gamma-ray detector, simulation of detection of landmine are reported. It can detect 10.8 MeV gamma-rays and estimate the incident angle of gamma-ray. Schematic layouts of the compact accelerator neutron resource, the compact Compton gamma camera and sensor unit, the estimation principle of incident angle of gamma-ray, experiments and comparison between the experimental results and the estimation results, a preliminary trial experiment system for sensing antipersonnel mines with neutron capture gamma-ray analysis are illustrated. (S.Y.)

  12. Fast-neutron capture in fissile and fertile nuclides

    International Nuclear Information System (INIS)

    Peelle, R.W.

    1982-01-01

    Extensive graphical and numerical presentations, available to the working group, assisted us in exploring the rich data base established through the labors of many skilled persons. Consistent with the meeting setting, the working group discussion concentrated on data for fast-breeder reactor (FBR) applications. All but 1 to 3% of the magnitude of cross section sensitivities of FBR parameters come from the energy region below approx. = 1.5 MeV, so the statistical model is the relevant theoretical concept. The Meeting emphasizes energies above approx. = 10 keV where resonance fluctuations are not a dominant factor. However, we should remember that approximately half the FBR sensitivity to 238 U capture data, as relfected in integral parameters, lies below 25 keV where resonance fluctuations are strong and resonance self-protection is a most important consideration in reactor physics. There are similar low-energy aspects to 239 Pu capture in that approx. = 30% of the FBR-parameter data sensitivity lies below approx. = 4 keV. Even with the discussion largely cofined to the approx. = 10 to 1500 keV region, the working group could only scratch the surface of the available body of information. The reader is referred to the papers presented at the Meeting and to the references contained therein in order to obtain a more detailed understanding of current issues related to fissile and fertile fast-neutron capture

  13. Implicit and semi-implicit schemes in the Versatile Advection Code : numerical tests

    NARCIS (Netherlands)

    Tóth, G.; Keppens, R.; Bochev, Mikhail A.

    1998-01-01

    We describe and evaluate various implicit and semi-implicit time integration schemes applied to the numerical simulation of hydrodynamical and magnetohydrodynamical problems. The schemes were implemented recently in the software package Versatile Advection Code, which uses modern shock capturing

  14. Radiative electron capture

    International Nuclear Information System (INIS)

    Biggerstaff, J.A.; Appleton, B.R.; Datz, S.; Moak, C.D.; Neelavathi, V.N.; Noggle, T.S.; Ritchie, R.H.; VerBeek, H.

    1975-01-01

    Some data are presented for radiative electron capture by fast moving ions. The radiative electron capture spectrum is shown for O 8+ in Ag, along with the energy dependence of the capture cross-section. A discrepancy between earlier data, theoretical prediction, and the present data is pointed out. (3 figs) (U.S.)

  15. NUMERICAL MULTIGROUP TRANSIENT ANALYSIS OF SLAB NUCLEAR REACTOR WITH THERMAL FEEDBACK

    Directory of Open Access Journals (Sweden)

    Filip Osuský

    2016-12-01

    Full Text Available The paper describes a new numerical code for multigroup transient analyses with thermal feedback. The code is developed at Institute of Nuclear and Physical Engineering. It is necessary to carefully investigate transient states of fast neutron reactors, due to recriticality issues after accident scenarios. The code solves numerical diffusion equation for 1D problem with possible neutron source incorporation. Crank-Nicholson numerical method is used for the transient states. The investigated cases are describing behavior of PWR fuel assembly inside of spent fuel pool and with the incorporated neutron source for better illustration of thermal feedback.

  16. Numerical analysis of bubble rising behavior in a liquid metal using MPS

    International Nuclear Information System (INIS)

    Chen Ronghua; Tian Wenxi; Zuo Juanli; Su Guanghui; Qiu Suizheng; Xu Jianhui

    2011-01-01

    Moving Particle Semi-Implicit (MPS) Method has advantages over the traditional mesh-based methods in the accurate capture of the vapor-liquid interface. In the present study, the numerical simulation of single bubble rising behavior in the liquid Pb-Bi alloy had been performed. The numerical results are provided for bubble shape deformation and rising velocity. Numerical simulation results indicate that as the bubble rises, the bubble exhibits in turn spherical, dimpled ellipsoidal, spherical-cap shapes. Terminal velocity of the bubble predicted by MPS agrees well with that predicted by Grace and increases with the initial bubble diameter. (authors)

  17. Double K-shell ionization in electron capture decay

    International Nuclear Information System (INIS)

    Intemann, R.L.

    1985-01-01

    Using a semirelativistic theory previously developed by the author, we have computed the total probability per K-capture event for the ionization of the remaining K electron for a dozen nuclides of interest. Based on hydrogenic wave functions and accurate to relative order (Zα) 2 , the theory takes into account the correlation between the two initial K electrons and permits adjustments for screening. Numerical results exhibiting the effects of screening are presented. A comprehensive comparison of the predictions of this theory, as well as those of other theoretical models, with recent experimental data is also given

  18. Carbon capture and storage-Investment strategies for the future?

    International Nuclear Information System (INIS)

    Rammerstorfer, Margarethe; Eisl, Roland

    2011-01-01

    The following article deals with real options modeling for investing into carbon capture and storage technologies. Herein, we derive two separate models. The first model incorporates a constant convenience yield and dividend for the investment project. In the second model, the convenience yield is allowed to follow a mean reverting process which seems to be more realistic, but also increases the model's complexity. Both frameworks are to be solved numerically. Therefore, we calibrate our model with respect to empirical data and provide insights into the models' sensitivity toward the chosen parameter values. We found that given the recently observable prices for carbon dioxide, an investment into C O2-storage facilities is not profitable. - Highlights: → Real options modeling for investing into carbon capture and storage technologies. → Given the recently observable prices for carbon dioxide, an investment into CO 2 -storage facilities is not profitable. → Investment decision is mainly affected by risk free rate and volatility.

  19. Numerical Oscillations Analysis for Nonlinear Delay Differential Equations in Physiological Control Systems

    Directory of Open Access Journals (Sweden)

    Qi Wang

    2012-01-01

    Full Text Available This paper deals with the oscillations of numerical solutions for the nonlinear delay differential equations in physiological control systems. The exponential θ-method is applied to p′(t=β0ωμp(t−τ/(ωμ+pμ(t−τ−γp(t and it is shown that the exponential θ-method has the same order of convergence as that of the classical θ-method. Several conditions under which the numerical solutions oscillate are derived. Moreover, it is proven that every nonoscillatory numerical solution tends to positive equilibrium of the continuous system. Finally, the main results are illustrated with numerical examples.

  20. 31 CFR 411.1 - Color illustrations authorized.

    Science.gov (United States)

    2010-07-01

    ... SERVICE, DEPARTMENT OF THE TREASURY COLOR ILLUSTRATIONS OF UNITED STATES CURRENCY § 411.1 Color... necessary plates or items for such printing or publishing, of color illustrations of U.S. currency provided... storage devices, and any other thing used in the making of the illustration that contain an image of the...

  1. Geometric capture and escape of a microswimmer colliding with an obstacle.

    Science.gov (United States)

    Spagnolie, Saverio E; Moreno-Flores, Gregorio R; Bartolo, Denis; Lauga, Eric

    2015-05-07

    Motivated by recent experiments, we consider the hydrodynamic capture of a microswimmer near a stationary spherical obstacle. Simulations of model equations show that a swimmer approaching a small spherical colloid is simply scattered. In contrast, when the colloid is larger than a critical size it acts as a passive trap: the swimmer is hydrodynamically captured along closed trajectories and endlessly orbits around the colloidal sphere. In order to gain physical insight into this hydrodynamic scattering problem, we address it analytically. We provide expressions for the critical trapping radius, the depth of the "basin of attraction," and the scattering angle, which show excellent agreement with our numerical findings. We also demonstrate and rationalize the strong impact of swimming-flow symmetries on the trapping efficiency. Finally, we give the swimmer an opportunity to escape the colloidal traps by considering the effects of Brownian, or active, diffusion. We show that in some cases the trapping time is governed by an Ornstein-Uhlenbeck process, which results in a trapping time distribution that is well-approximated as inverse-Gaussian. The predictions again compare very favorably with the numerical simulations. We envision applications of the theory to bioremediation, microorganism sorting techniques, and the study of bacterial populations in heterogeneous or porous environments.

  2. The National Carbon Capture Center at the Power Systems Development Facility

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2014-07-14

    The Power Systems Development Facility (PSDF) is a state-of-the-art test center sponsored by the U.S. Department of Energy (DOE) and dedicated to the advancement of clean coal technology. In addition to the development of high efficiency coal gasification processes, the PSDF features the National Carbon Capture Center (NCCC) to promote new technologies for CO2 capture from coal-derived flue gas and syngas. The NCCC includes multiple, adaptable test skids that allow technology development of CO2 capture concepts using coal-derived flue gas and syngas in industrial settings. Because of the ability to operate under a wide range of flow rates and process conditions, research at the NCCC can effectively evaluate technologies at various levels of maturity and accelerate their development paths to commercialization. During the calendar year 2013 portion of the Budget Period Four reporting period, efforts at the NCCC focused on post-combustion CO2 capture, gasification, and pre-combustion CO2 capture technology testing. Preparations for future testing were on-going as well, and involved facility upgrades and collaboration with numerous technology developers. In the area of post-combustion, testing was conducted on an enzyme-based technology, advanced solvents from two major developers, and a gas separation membrane. During the year, the gasification process was operated for three test runs, supporting development of water-gas shift and COS hydrolysis catalysts, a mercury sorbent, and several gasification support technologies. Syngas produced during gasification operation was also used for pre-combustion capture technologies, including gas separation membranes from three different technology developers, a CO2 sorbent, and CO2 solvents.

  3. Numerical study of drop spreading on a flat surface

    Science.gov (United States)

    Wang, Sheng; Desjardins, Olivier

    2017-11-01

    In this talk, we perform a numerical study of a droplet on a flat surface with special emphasis on capturing the spreading dynamics. The computational methodology employed is tailored for simulating large-scale two-phase flows within complex geometries. It combines a conservative level-set method to capture the liquid-gas interface, a conservative immersed boundary method to represent the solid-fluid interface, and a sub-grid curvature model at the triple-point to implicitly impose the contact angle of the liquid-gas interface. The performance of the approach is assessed in the inertial droplet spreading regime, the viscous spreading regime of high viscosity drops, and with the capillary oscillation of low viscosity droplets.

  4. 48 CFR 9904.401-60 - Illustrations.

    Science.gov (United States)

    2010-10-01

    ... Section 9904.401-60 Federal Acquisition Regulations System COST ACCOUNTING STANDARDS BOARD, OFFICE OF FEDERAL PROCUREMENT POLICY, OFFICE OF MANAGEMENT AND BUDGET PROCUREMENT PRACTICES AND COST ACCOUNTING STANDARDS COST ACCOUNTING STANDARDS 9904.401-60 Illustrations. (a) The following examples are illustrative...

  5. 48 CFR 9904.409-60 - Illustrations.

    Science.gov (United States)

    2010-10-01

    ... Section 9904.409-60 Federal Acquisition Regulations System COST ACCOUNTING STANDARDS BOARD, OFFICE OF FEDERAL PROCUREMENT POLICY, OFFICE OF MANAGEMENT AND BUDGET PROCUREMENT PRACTICES AND COST ACCOUNTING STANDARDS COST ACCOUNTING STANDARDS 9904.409-60 Illustrations. The following examples are illustrative of...

  6. Radiology illustrated. Uroradiology. 2. ed.

    International Nuclear Information System (INIS)

    Kim, Seung Hyup

    2012-01-01

    Uroradiology is an up-to-date, image-oriented reference in the style of a teaching file that has been designed specifically to be of value in clinical practice. All aspects of the imaging of urologic diseases are covered, and case studies illustrate the findings obtained with the relevant imaging modalities in both common and uncommon conditions. Most chapters focus on a particular clinical problem, but normal findings, congenital anomalies, and interventions are also discussed and illustrated. In this second edition, the range and quality of the illustrations have been enhanced, and many schematic drawings have been added to help readers memorize characteristic imaging findings through pattern recognition. The accompanying text is concise and informative. Besides serving as an outstanding aid to differential diagnosis, this book will provide a user-friendly review tool for certification or recertification in radiology. (orig.)

  7. A Nonlinear Dynamic Subscale Model for Partially Resolved Numerical Simulation (PRNS)/Very Large Eddy Simulation (VLES) of Internal Non-Reacting Flows

    Science.gov (United States)

    Shih, Tsan-Hsing; Liu, nan-Suey

    2010-01-01

    A brief introduction of the temporal filter based partially resolved numerical simulation/very large eddy simulation approach (PRNS/VLES) and its distinct features are presented. A nonlinear dynamic subscale model and its advantages over the linear subscale eddy viscosity model are described. In addition, a guideline for conducting a PRNS/VLES simulation is provided. Results are presented for three turbulent internal flows. The first one is the turbulent pipe flow at low and high Reynolds numbers to illustrate the basic features of PRNS/VLES; the second one is the swirling turbulent flow in a LM6000 single injector to further demonstrate the differences in the calculated flow fields resulting from the nonlinear model versus the pure eddy viscosity model; the third one is a more complex turbulent flow generated in a single-element lean direct injection (LDI) combustor, the calculated result has demonstrated that the current PRNS/VLES approach is capable of capturing the dynamically important, unsteady turbulent structures while using a relatively coarse grid.

  8. 48 CFR 9904.404-60 - Illustrations.

    Science.gov (United States)

    2010-10-01

    ... Section 9904.404-60 Federal Acquisition Regulations System COST ACCOUNTING STANDARDS BOARD, OFFICE OF FEDERAL PROCUREMENT POLICY, OFFICE OF MANAGEMENT AND BUDGET PROCUREMENT PRACTICES AND COST ACCOUNTING STANDARDS COST ACCOUNTING STANDARDS 9904.404-60 Illustrations. (a) Illustrations of costs which must be...

  9. 48 CFR 9904.402-60 - Illustrations.

    Science.gov (United States)

    2010-10-01

    ... Section 9904.402-60 Federal Acquisition Regulations System COST ACCOUNTING STANDARDS BOARD, OFFICE OF FEDERAL PROCUREMENT POLICY, OFFICE OF MANAGEMENT AND BUDGET PROCUREMENT PRACTICES AND COST ACCOUNTING STANDARDS COST ACCOUNTING STANDARDS 9904.402-60 Illustrations. (a) Illustrations of costs which are incurred...

  10. A new scheme to treat the numerical Tcherenkov instability for electromagnetic particle simulations

    International Nuclear Information System (INIS)

    Assous, F.; Degond, P.; Segre, J.; Degond, P.

    1997-10-01

    The aim of this paper is to present a new explicit time scheme for electromagnetic particle simulations. The main property of this new scheme, which depends on a parameter, is to reduce and in some cases to suppress numerical instabilities that can appear in this context, and are widely described in the literature. Other numerical properties are also investigated, and a numerical example is finally given to illustrate our purpose. This scheme is expected to be useful in the field of plasma modelling. (authors)

  11. Numerical Hydrodynamics in Special Relativity.

    Science.gov (United States)

    Martí, José Maria; Müller, Ewald

    2003-01-01

    This review is concerned with a discussion of numerical methods for the solution of the equations of special relativistic hydrodynamics (SRHD). Particular emphasis is put on a comprehensive review of the application of high-resolution shock-capturing methods in SRHD. Results of a set of demanding test bench simulations obtained with different numerical SRHD methods are compared. Three applications (astrophysical jets, gamma-ray bursts and heavy ion collisions) of relativistic flows are discussed. An evaluation of various SRHD methods is presented, and future developments in SRHD are analyzed involving extension to general relativistic hydrodynamics and relativistic magneto-hydrodynamics. The review further provides FORTRAN programs to compute the exact solution of a 1D relativistic Riemann problem with zero and nonzero tangential velocities, and to simulate 1D relativistic flows in Cartesian Eulerian coordinates using the exact SRHD Riemann solver and PPM reconstruction. Supplementary material is available for this article at 10.12942/lrr-2003-7 and is accessible for authorized users.

  12. Illustrations of the twin paradox

    International Nuclear Information System (INIS)

    Rebhan, E.

    1985-01-01

    In order to provide a more intuitive understanding of the twin paradox, several illustrations of this are presented. In one of these, each of the twins is equipped with a lamp whose monochromatic light can be observed by the other. In other illustrations the travelling twin uses an Einstein train instead of a space ship, all the cars of the train and all stations along the route of the train being equipped with clocks. (author)

  13. Capturing Thoughts, Capturing Minds?

    DEFF Research Database (Denmark)

    Nielsen, Janni

    2004-01-01

    Think Aloud is cost effective, promises access to the user's mind and is the applied usability technique. But 'keep talking' is difficult, besides, the multimodal interface is visual not verbal. Eye-tracking seems to get around the verbalisation problem. It captures the visual focus of attention...

  14. Influence of the Casserius Tables on fetal anatomy illustration and how we envision the unborn.

    Science.gov (United States)

    Heilemann, Heidi A

    2011-01-01

    The paper demonstrates how visual representation of the fetus in early anatomy texts influenced the reader's perception of the unborn child as an autonomous being. The health, art, and history literatures were used as sources. Original texts and illustrations, with particular attention paid to the Casserius Tables, published by Andreas Spigelius in 1627, are discussed. A review of the literature was conducted to identify and analyze published renderings, reproductions, and discussion of images of the unborn child. Original anatomy atlases were consulted. Artists' renderings of a particularly vulnerable state of human life influenced early perceptions of the status of the unborn child. The images show fetuses as highly independent, providing a visual cue that life is fully formed in utero. The legacy of the Casserius Tables is that they are still able to capture our attention because they portray the idea of a fetus and newborn even more clearly than our modern representations of this charged topic. The use of deceptive realism provides the viewer with an accessible visual representation of the unborn child. These early anatomy illustrations continue to influence modern-day perception of the unborn child as a separate being, completely autonomous from the mother.

  15. Investigation of the Capture of Magnetic Particles From High-Viscosity Fluids Using Permanent Magnets.

    Science.gov (United States)

    Garraud, Alexandra; Velez, Camilo; Shah, Yash; Garraud, Nicolas; Kozissnik, Bettina; Yarmola, Elena G; Allen, Kyle D; Dobson, Jon; Arnold, David P

    2016-02-01

    This paper investigates the practicality of using a small, permanent magnet to capture magnetic particles out of high-viscosity biological fluids, such as synovial fluid. Numerical simulations are used to predict the trajectory of magnetic particles toward the permanent magnet. The simulations are used to determine a "collection volume" with a time-dependent size and shape, which determines the number of particles that can be captured from the fluid in a given amount of time. The viscosity of the fluid strongly influences the velocity of the magnetic particles toward the magnet, hence, the collection volume after a given time. In regards to the design of the magnet, the overall size is shown to most strongly influence the collection volume in comparison to the magnet shape or aspect ratio. Numerical results showed good agreement with in vitro experimental magnetic collection results. In the long term, this paper aims to facilitate optimization of the collection of magnetic particle-biomarker conjugates from high-viscosity biological fluids without the need to remove the fluid from a patient.

  16. Numerical simulation of flow fields and particle trajectories

    DEFF Research Database (Denmark)

    Mayer, Stefan

    2000-01-01

    . The time-dependent flow is approximated with a continuous sequence of steady state creeping flow fields, where metachronously beating ciliary bands are modelled by linear combinations of singularity solutions to the Stokes equations. Generally, the computed flow fields can be divided into an unsteady......A model describing the ciliary driven flow and motion of suspended particles in downstream suspension feeders is developed. The quasi-steady Stokes equations for creeping flow are solved numerically in an unbounded fluid domain around cylindrical bodies using a boundary integral formulation...... in the simulated unsteady ciliary driven flow. A fraction of particles appear to follow trajectories, that resemble experimentally observed particle capture events in the downstream feeding system of the polycheate Sabella penicillus, indicating that particles can be captured by ciliary systems without mechanical...

  17. Detection of the onset of numerical chaotic instabilities by lyapunov exponents

    Directory of Open Access Journals (Sweden)

    Alicia Serfaty De Markus

    2001-01-01

    Full Text Available It is commonly found in the fixed-step numerical integration of nonlinear differential equations that the size of the integration step is opposite related to the numerical stability of the scheme and to the speed of computation. We present a procedure that establishes a criterion to select the largest possible step size before the onset of chaotic numerical instabilities, based upon the observation that computational chaos does not occur in a smooth, continuous way, but rather abruptly, as detected by examining the largest Lyapunov exponent as a function of the step size. For completeness, examination of the bifurcation diagrams with the step reveals the complexity imposed by the algorithmic discretization, showing the robustness of a scheme to numerical instabilities, illustrated here for explicit and implicit Euler schemes. An example of numerical suppression of chaos is also provided.

  18. CDW (continuum distorted wave) type approximation for electron capture at large angles

    International Nuclear Information System (INIS)

    Fojon, O.A.; Maidagan, J.M.

    1990-01-01

    A calculation is made for the probability of electron capture in shell K at great angles using a second order symmetrical model used related to the continuum distorted wave (CDW) approximation. The influence of Coulomb distortion of nuclei is studied and compared with OBK and CIS type calculations. Numerical results are compared with experimental results of the collision of H + on C at intermediate energies. (Author). 19 refs., 2 figs

  19. "Illustrating the Machinery of Life": Viruses

    Science.gov (United States)

    Goodsell, David S.

    2012-01-01

    Data from electron microscopy, X-ray crystallography, and biophysical analysis are used to create illustrations of viruses in their cellular context. This report describes the scientific data and artistic methods used to create three illustrations: a depiction of the poliovirus lifecycle, budding of influenza virus from a cell surface, and a…

  20. Numerical solutions of stochastic Lotka-Volterra equations via operational matrices

    Directory of Open Access Journals (Sweden)

    F. Hosseini Shekarabi

    2016-03-01

    Full Text Available In this paper, an efficient and convenient method for numerical solutions of stochastic Lotka-Volterra dynamical system is proposed. Here, we consider block pulse functions and their operational matrices of integration. Illustrative example is included to demonstrate the procedure and accuracy of the operational matrices based on block pulse functions.

  1. Porous Organic Polymers for CO2 Capture

    KAUST Repository

    Teng, Baiyang

    2013-05-01

    Carbon dioxide (CO2) has long been regarded as the major greenhouse gas, which leads to numerous negative effects on global environment. The capture and separation of CO2 by selective adsorption using porous materials proves to be an effective way to reduce the emission of CO2 to atmosphere. Porous organic polymers (POPs) are promising candidates for this application due to their readily tunable textual properties and surface functionalities. The objective of this thesis work is to develop new POPs with high CO2 adsorption capacities and CO2/N2 selectivities for post-combustion effluent (e.g. flue gas) treatment. We will also exploit the correlation between the CO2 capture performance of POPs and their textual properties/functionalities. Chapters Two focuses on the study of a group of porous phenolic-aldehyde polymers (PPAPs) synthesized by a catalyst-free method, the CO2 capture capacities of these PPAPs exceed 2.0 mmol/g at 298 K and 1 bar, while keeping CO2/N2 selectivity of more than 30 at the same time. Chapter Three reports the gas adsorption results of different hyper-cross-linked polymers (HCPs), which indicate that heterocyclo aromatic monomers can greatly enhance polymers’ CO2/N2 selectivities, and the N-H bond is proved to the active CO2 adsorption center in the N-contained (e.g. pyrrole) HCPs, which possess the highest selectivities of more than 40 at 273 K when compared with other HCPs. Chapter Four emphasizes on the chemical modification of a new designed polymer of intrinsic microporosity (PIM) with high CO2/N2 selectivity (50 at 273 K), whose experimental repeatability and chemical stability prove excellent. In Chapter Five, we demonstrate an improvement of both CO2 capture capacity and CO2/N2 selectivity by doping alkali metal ions into azo-polymers, which leads a promising method to the design of new porous organic polymers.

  2. Carbon captured from the air

    International Nuclear Information System (INIS)

    Keith, D.

    2008-01-01

    This article presented an innovative way to achieve the efficient capture of atmospheric carbon. A team of scientists from the University of Calgary's Institute for Sustainable Energy, Environment and Economy have shown that it is possible to reduce carbon dioxide (CO 2 ) using a simple machine that can capture the trace amount of CO 2 present in ambient air at any place on the planet. The thermodynamics of capturing the small concentrations of CO 2 from the air is only slightly more difficult than capturing much larger concentrations of CO 2 from power plants. The research is significant because it offers a way to capture CO 2 emissions from transportation sources such as vehicles and airplanes, which represent more than half of the greenhouse gases emitted on Earth. The energy efficient and cost effective air capture technology could complement other approaches for reducing emissions from the transportation sector, such as biofuels and electric vehicles. Air capture differs from carbon capture and storage (CCS) technology used at coal-fired power plants where CO 2 is captured and pipelined for permanent storage underground. Air capture can capture the CO 2 that is present in ambient air and store it wherever it is cheapest. The team at the University of Calgary showed that CO 2 could be captured directly from the air with less than 100 kWhrs of electricity per tonne of CO 2 . A custom-built tower was able to capture the equivalent of 20 tonnes per year of CO 2 on a single square meter of scrubbing material. The team devised a way to use a chemical process from the pulp and paper industry to cut the energy cost of air capture in half. Although the technology is only in its early stage, it appears that CO 2 could be captured from the air with an energy demand comparable to that needed for CO 2 capture from conventional power plants, but costs will be higher. The simple, reliable and scalable technology offers an opportunity to build a commercial-scale plant. 1 fig

  3. A student's guide to numerical methods

    CERN Document Server

    Hutchinson, Ian H

    2015-01-01

    This concise, plain-language guide for senior undergraduates and graduate students aims to develop intuition, practical skills and an understanding of the framework of numerical methods for the physical sciences and engineering. It provides accessible self-contained explanations of mathematical principles, avoiding intimidating formal proofs. Worked examples and targeted exercises enable the student to master the realities of using numerical techniques for common needs such as solution of ordinary and partial differential equations, fitting experimental data, and simulation using particle and Monte Carlo methods. Topics are carefully selected and structured to build understanding, and illustrate key principles such as: accuracy, stability, order of convergence, iterative refinement, and computational effort estimation. Enrichment sections and in-depth footnotes form a springboard to more advanced material and provide additional background. Whether used for self-study, or as the basis of an accelerated introdu...

  4. The Scientist as Illustrator.

    Science.gov (United States)

    Iwasa, Janet H

    2016-04-01

    Proficiency in art and illustration was once considered an essential skill for biologists, because text alone often could not suffice to describe observations of biological systems. With modern imaging technology, it is no longer necessary to illustrate what we can see by eye. However, in molecular and cellular biology, our understanding of biological processes is dependent on our ability to synthesize diverse data to generate a hypothesis. Creating visual models of these hypotheses is important for generating new ideas and for communicating to our peers and to the public. Here, I discuss the benefits of creating visual models in molecular and cellular biology and consider steps to enable researchers to become more effective visual communicators. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Capture by colour: evidence for dimension-specific singleton capture.

    Science.gov (United States)

    Harris, Anthony M; Becker, Stefanie I; Remington, Roger W

    2015-10-01

    Previous work on attentional capture has shown the attentional system to be quite flexible in the stimulus properties it can be set to respond to. Several different attentional "modes" have been identified. Feature search mode allows attention to be set for specific features of a target (e.g., red). Singleton detection mode sets attention to respond to any discrepant item ("singleton") in the display. Relational search sets attention for the relative properties of the target in relation to the distractors (e.g., redder, larger). Recently, a new attentional mode was proposed that sets attention to respond to any singleton within a particular feature dimension (e.g., colour; Folk & Anderson, 2010). We tested this proposal against the predictions of previously established attentional modes. In a spatial cueing paradigm, participants searched for a colour target that was randomly either red or green. The nature of the attentional control setting was probed by presenting an irrelevant singleton cue prior to the target display and assessing whether it attracted attention. In all experiments, the cues were red, green, blue, or a white stimulus rapidly rotated (motion cue). The results of three experiments support the existence of a "colour singleton set," finding that all colour cues captured attention strongly, while motion cues captured attention only weakly or not at all. Notably, we also found that capture by motion cues in search for colour targets was moderated by their frequency; rare motion cues captured attention (weakly), while frequent motion cues did not.

  6. Materials For Gas Capture, Methods Of Making Materials For Gas Capture, And Methods Of Capturing Gas

    KAUST Repository

    Polshettiwar, Vivek

    2013-06-20

    In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein, embodiments of the present disclosure, in one aspect, relate to materials that can be used for gas (e.g., CO.sub.2) capture, methods of making materials, methods of capturing gas (e.g., CO.sub.2), and the like, and the like.

  7. Seismic behavior of an Italian Renaissance Sanctuary: Damage assessment by numerical modelling

    Science.gov (United States)

    Clementi, Francesco; Nespeca, Andrea; Lenci, Stefano

    2016-12-01

    The paper deals with modelling and analysis of architectural heritage through the discussion of an illustrative case study: the Medieval Sanctuary of Sant'Agostino (Offida, Italy). Using the finite element technique, a 3D numerical model of the sanctuary is built, and then used to identify the main sources of the damages. The work shows that advanced numerical analyses could offer significant information for the understanding of the causes of existing damage and, more generally, on the seismic vulnerability.

  8. Time's arrow: A numerical experiment

    Science.gov (United States)

    Fowles, G. Richard

    1994-04-01

    The dependence of time's arrow on initial conditions is illustrated by a numerical example in which plane waves produced by an initial pressure pulse are followed as they are multiply reflected at internal interfaces of a layered medium. Wave interactions at interfaces are shown to be analogous to the retarded and advanced waves of point sources. The model is linear and the calculation is exact and demonstrably time reversible; nevertheless the results show most of the features expected of a macroscopically irreversible system, including the approach to the Maxwell-Boltzmann distribution, ergodicity, and concomitant entropy increase.

  9. Microfluidic propulsion by the metachronal beating of magnetic artificial cilia : a numerical analysis

    NARCIS (Netherlands)

    Khaderi, S.N.; Toonder, den J.M.J.; Onck, P.R.

    2011-01-01

    In this work we study the effect of metachronal waves on the flow created by magnetically driven plate-like artificial cilia in microchannels using numerical simulations. The simulations are performed using a coupled magneto-mechanical solid–fluid computational model that captures the physical

  10. Microfluidic propulsion by the metachronal beating of magnetic artificial cilia : A numerical analysis

    NARCIS (Netherlands)

    Khaderi, S. N.; den Toonder, J.M.J.; Onck, P. R.

    2011-01-01

    In this work we study the effect of metachronal waves on the flow created by magnetically driven plate-like artificial cilia in microchannels using numerical simulations. The simulations are performed using a coupled magneto-mechanical solid fluid computational model that captures the physical

  11. Sourcing of Steam and Electricity for Carbon Capture Retrofits.

    Science.gov (United States)

    Supekar, Sarang D; Skerlos, Steven J

    2017-11-07

    This paper compares different steam and electricity sources for carbon capture and sequestration (CCS) retrofits of pulverized coal (PC) and natural gas combined cycle (NGCC) power plants. Analytical expressions for the thermal efficiency of these power plants are derived under 16 different CCS retrofit scenarios for the purpose of illustrating their environmental and economic characteristics. The scenarios emerge from combinations of steam and electricity sources, fuel used in each source, steam generation equipment and process details, and the extent of CO 2 capture. Comparing these scenarios reveals distinct trade-offs between thermal efficiency, net power output, levelized cost, profit, and net CO 2 reduction. Despite causing the highest loss in useful power output, bleeding steam and extracting electric power from the main power plant to meet the CCS plant's electricity and steam demand maximizes plant efficiency and profit while minimizing emissions and levelized cost when wholesale electricity prices are below 4.5 and 5.2 US¢/kWh for PC-CCS and NGCC-CCS plants, respectively. At prices higher than these higher profits for operating CCS retrofits can be obtained by meeting 100% of the CCS plant's electric power demand using an auxiliary natural gas turbine-based combined heat and power plant.

  12. A deterministic combination of numerical and physical models for coastal waves

    DEFF Research Database (Denmark)

    Zhang, Haiwen

    2006-01-01

    of numerical and physical modelling hence provides an attractive alternative to the use of either tool on it's own. The goal of this project has been to develop a deterministically combined numerical/physical model where the physical wave tank is enclosed in a much larger computational domain, and the two......Numerical and physical modelling are the two main tools available for predicting the influence of water waves on coastlines and structures placed in the near-shore environment. Numerical models can cover large areas at the correct scale, but are limited in their ability to capture strong...... nonlinearities, wave breaking, splash, mixing, and other such complicated physics. Physical models naturally include the real physics (at the model scale), but are limited by the physical size of the facility and must contend with the fact that different physical effects scale differently. An integrated use...

  13. Numerical Modeling of Ocean Circulation

    Science.gov (United States)

    Miller, Robert N.

    2007-01-01

    The modelling of ocean circulation is important not only for its own sake, but also in terms of the prediction of weather patterns and the effects of climate change. This book introduces the basic computational techniques necessary for all models of the ocean and atmosphere, and the conditions they must satisfy. It describes the workings of ocean models, the problems that must be solved in their construction, and how to evaluate computational results. Major emphasis is placed on examining ocean models critically, and determining what they do well and what they do poorly. Numerical analysis is introduced as needed, and exercises are included to illustrate major points. Developed from notes for a course taught in physical oceanography at the College of Oceanic and Atmospheric Sciences at Oregon State University, this book is ideal for graduate students of oceanography, geophysics, climatology and atmospheric science, and researchers in oceanography and atmospheric science. Features examples and critical examination of ocean modelling and results Demonstrates the strengths and weaknesses of different approaches Includes exercises to illustrate major points and supplement mathematical and physical details

  14. Carbon captured from the air

    Energy Technology Data Exchange (ETDEWEB)

    Keith, D. [Calgary Univ., AB (Canada)

    2008-10-15

    This article presented an innovative way to achieve the efficient capture of atmospheric carbon. A team of scientists from the University of Calgary's Institute for Sustainable Energy, Environment and Economy have shown that it is possible to reduce carbon dioxide (CO{sub 2}) using a simple machine that can capture the trace amount of CO{sub 2} present in ambient air at any place on the planet. The thermodynamics of capturing the small concentrations of CO{sub 2} from the air is only slightly more difficult than capturing much larger concentrations of CO{sub 2} from power plants. The research is significant because it offers a way to capture CO{sub 2} emissions from transportation sources such as vehicles and airplanes, which represent more than half of the greenhouse gases emitted on Earth. The energy efficient and cost effective air capture technology could complement other approaches for reducing emissions from the transportation sector, such as biofuels and electric vehicles. Air capture differs from carbon capture and storage (CCS) technology used at coal-fired power plants where CO{sub 2} is captured and pipelined for permanent storage underground. Air capture can capture the CO{sub 2} that is present in ambient air and store it wherever it is cheapest. The team at the University of Calgary showed that CO{sub 2} could be captured directly from the air with less than 100 kWhrs of electricity per tonne of CO{sub 2}. A custom-built tower was able to capture the equivalent of 20 tonnes per year of CO{sub 2} on a single square meter of scrubbing material. The team devised a way to use a chemical process from the pulp and paper industry to cut the energy cost of air capture in half. Although the technology is only in its early stage, it appears that CO{sub 2} could be captured from the air with an energy demand comparable to that needed for CO{sub 2} capture from conventional power plants, but costs will be higher. The simple, reliable and scalable technology

  15. Design of analog networks in the control theory formulation. Part 2: Numerical results

    OpenAIRE

    Zemliak, A. M.

    2005-01-01

    The paper presents numerical results of design of nonlinear electronic networks based on the problem formulation in terms of the control theory. Several examples illustrate the prospects of the approach suggested in the first part of the work.

  16. Numerical simulations of a reduced model for blood coagulation

    Science.gov (United States)

    Pavlova, Jevgenija; Fasano, Antonio; Sequeira, Adélia

    2016-04-01

    In this work, the three-dimensional numerical resolution of a complex mathematical model for the blood coagulation process is presented. The model was illustrated in Fasano et al. (Clin Hemorheol Microcirc 51:1-14, 2012), Pavlova et al. (Theor Biol 380:367-379, 2015). It incorporates the action of the biochemical and cellular components of blood as well as the effects of the flow. The model is characterized by a reduction in the biochemical network and considers the impact of the blood slip at the vessel wall. Numerical results showing the capacity of the model to predict different perturbations in the hemostatic system are discussed.

  17. Diffuse-Interface Capturing Methods for Compressible Two-Phase Flows

    Science.gov (United States)

    Saurel, Richard; Pantano, Carlos

    2018-01-01

    Simulation of compressible flows became a routine activity with the appearance of shock-/contact-capturing methods. These methods can determine all waves, particularly discontinuous ones. However, additional difficulties may appear in two-phase and multimaterial flows due to the abrupt variation of thermodynamic properties across the interfacial region, with discontinuous thermodynamical representations at the interfaces. To overcome this difficulty, researchers have developed augmented systems of governing equations to extend the capturing strategy. These extended systems, reviewed here, are termed diffuse-interface models, because they are designed to compute flow variables correctly in numerically diffused zones surrounding interfaces. In particular, they facilitate coupling the dynamics on both sides of the (diffuse) interfaces and tend to the proper pure fluid-governing equations far from the interfaces. This strategy has become efficient for contact interfaces separating fluids that are governed by different equations of state, in the presence or absence of capillary effects, and with phase change. More sophisticated materials than fluids (e.g., elastic-plastic materials) have been considered as well.

  18. Role of the cluster structure of {sup 7}Li in the dynamics of fragment capture

    Energy Technology Data Exchange (ETDEWEB)

    Shrivastava, A., E-mail: aradhana@barc.gov.in [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Navin, A. [GANIL, CEA/DSM - CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); Diaz-Torres, A. [ECT, Villa Tambosi, I-38123 Villazzano, Trento (Italy); Nanal, V. [DNAP, Tata Institute of Fundamental Research, Mumbai 400005 (India); Ramachandran, K. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Rejmund, M. [GANIL, CEA/DSM - CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); Bhattacharyya, S. [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700064 (India); Chatterjee, A.; Kailas, S. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Lemasson, A. [GANIL, CEA/DSM - CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); Palit, R. [DNAP, Tata Institute of Fundamental Research, Mumbai 400005 (India); Parkar, V.V. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Pillay, R.G. [DNAP, Tata Institute of Fundamental Research, Mumbai 400005 (India); Rout, P.C. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Sawant, Y. [DNAP, Tata Institute of Fundamental Research, Mumbai 400005 (India)

    2013-01-08

    Exclusive measurements of prompt {gamma}-rays from the heavy-residues with various light charged particles in the {sup 7}Li + {sup 198}Pt system, at an energy near the Coulomb barrier (E/V{sub b}{approx}1.6) are reported. Recent dynamic classical trajectory calculations, constrained by the measured fusion, {alpha}- and t-capture cross-sections have been used to explain the excitation energy dependence of the residue cross-sections. These calculations distinctly illustrate a two-step process, breakup followed by fusion, in case of the capture of t and {alpha} clusters; whereas for {sup 6}He+p and {sup 5}He+d configurations, massive transfer is inferred to be the dominant mechanism. The present work clearly demonstrates the role played by the cluster structures of {sup 7}Li in understanding the reaction dynamics at energies around the Coulomb barrier.

  19. Proton injection and RF capture in the national spallation neutron source

    International Nuclear Information System (INIS)

    Luccio, A.U.; Beebe-Wang, J.; Maletic, D.

    1997-01-01

    The accelerator system for the 1 to 5 MW National Spallation Neutron Source (NSNS) consists of a linac followed by a 1 GeV proton accumulator ring. Since the ring is a very high current machine, the injection and rf capture of the protons is deeply affected by transverse and longitudinal space charge effects. Results of numerical simulation of the process are presented together with considerations on methods and results of space charge treatment in high intensity proton storage rings

  20. Direct numerical simulation of bubbles with parallelized adaptive mesh refinement

    International Nuclear Information System (INIS)

    Talpaert, A.

    2015-01-01

    The study of two-phase Thermal-Hydraulics is a major topic for Nuclear Engineering for both security and efficiency of nuclear facilities. In addition to experiments, numerical modeling helps to knowing precisely where bubbles appear and how they behave, in the core as well as in the steam generators. This work presents the finest scale of representation of two-phase flows, Direct Numerical Simulation of bubbles. We use the 'Di-phasic Low Mach Number' equation model. It is particularly adapted to low-Mach number flows, that is to say flows which velocity is much slower than the speed of sound; this is very typical of nuclear thermal-hydraulics conditions. Because we study bubbles, we capture the front between vapor and liquid phases thanks to a downward flux limiting numerical scheme. The specific discrete analysis technique this work introduces is well-balanced parallel Adaptive Mesh Refinement (AMR). With AMR, we refined the coarse grid on a batch of patches in order to locally increase precision in areas which matter more, and capture fine changes in the front location and its topology. We show that patch-based AMR is very adapted for parallel computing. We use a variety of physical examples: forced advection, heat transfer, phase changes represented by a Stefan model, as well as the combination of all those models. We will present the results of those numerical simulations, as well as the speed up compared to equivalent non-AMR simulation and to serial computation of the same problems. This document is made up of an abstract and the slides of the presentation. (author)

  1. Can Strategies Facilitate Learning from Illustrated Science Texts?

    Science.gov (United States)

    Iding, Marie K.

    2000-01-01

    Examines the effectiveness of schema training in illustration types and text-illustration relations for learning from college level physiology texts and discusses findings that are consistent with prior research on learning from illustrated materials and with dual coding theory. Considers future directions for strategy training research and…

  2. Numerical Simulation of the Oscillations in a Mixer: An Internal Aeroacoustic Feedback System

    Science.gov (United States)

    Jorgenson, Philip C. E.; Loh, Ching Y.

    2004-01-01

    The space-time conservation element and solution element method is employed to numerically study the acoustic feedback system in a high temperature, high speed wind tunnel mixer. The computation captures the self-sustained feedback loop between reflecting Mach waves and the shear layer. This feedback loop results in violent instabilities that are suspected of causing damage to some tunnel components. The computed frequency is in good agreement with the available experimental data. The physical phenomena are explained based on the numerical results.

  3. Increased-accuracy numerical modeling of electron-optical systems with space-charge

    International Nuclear Information System (INIS)

    Sveshnikov, V.

    2011-01-01

    This paper presents a method for improving the accuracy of space-charge computation for electron-optical systems. The method proposes to divide the computational region into two parts: a near-cathode region in which analytical solutions are used and a basic one in which numerical methods compute the field distribution and trace electron ray paths. A numerical method is used for calculating the potential along the interface, which involves solving a non-linear equation. Preliminary results illustrating the improvement of accuracy and the convergence of the method for a simple test example are presented.

  4. A Fractional Supervision Game Model of Multiple Stakeholders and Numerical Simulation

    Directory of Open Access Journals (Sweden)

    Rongwu Lu

    2017-01-01

    Full Text Available Considering the popular use of a certain kind of supervision management problem in many fields, we firstly build an ordinary supervision game model of multiple stakeholders. Secondly, a fractional supervision game model is set up and solved based on the theory of fractional calculus and a predictor-corrector numerical approach. Thirdly, the methods of phase diagram and time series graph were applied to simulate and analyse the dynamic process of the fractional order game model. Results of numerical solutions are given to illustrate our conclusions and referred to the practice.

  5. Interactive Numerical and Symbolic Analysis: A New Paradigm for Teaching Electronics

    Directory of Open Access Journals (Sweden)

    Jean-Claude Thomassian

    2008-09-01

    Full Text Available Analog Insydes, Mathematica’s symbolic circuit analysis toolbox, uses modern algorithms of expression simplification depending on comparisons with a numerical reference solution of the circuit under investigation. Some insight is offered on how the complexity of an expression barrier is overcome followed by two classical examples, a BJT emitter follower and a MOSFET common-gate amplifier stage to illustrate the proposed method at work. A concluding section discusses that time spent teaching introductory electronics by computer-aided circuit analysis, interactive numerical and symbolic, is a worthwhile investment.

  6. Physical and numerical modelling of low mach number compressible flows

    International Nuclear Information System (INIS)

    Paillerre, H.; Clerc, S.; Dabbene, F.; Cueto, O.

    1999-01-01

    This article reviews various physical models that may be used to describe compressible flow at low Mach numbers, as well as the numerical methods developed at DRN to discretize the different systems of equations. A selection of thermal-hydraulic applications illustrate the need to take into account compressibility and multidimensional effects as well as variable flow properties. (authors)

  7. New lithology compensated capture gamma ray system

    International Nuclear Information System (INIS)

    Peatross, R.F.

    1976-01-01

    The results of the HYDROCARBON* log after a series of field tests in which gamma rays resulting from thermal neutron capture were measured utilizing an energy analyzer and a scintillation counter of unique construction are reported. A brief discussion covers the nuclear physics required for an understanding of gamma spectral logging. Included in the explanation will be the effects of different atoms on neutrons and photons. The HYDROCARBON log utilizes these nuclear principles to record cased hole measurements and quantitatively distinguish possible productive zones from non-productive zones. Different field examples are illustrated showing the response to shaly sands, porosity and water salinity. Interpretation techniques are discussed both qualitatively and quantitatively. The HYDROCARBON log has proven to be a reliable device in the determination of water saturation in sands behind casing even when shale content and porosity are not well known. This technique is also valuable in the location of the present position of gas--oil contacts and water levels

  8. A numerical scheme for the generalized Burgers–Huxley equation

    Directory of Open Access Journals (Sweden)

    Brajesh K. Singh

    2016-10-01

    Full Text Available In this article, a numerical solution of generalized Burgers–Huxley (gBH equation is approximated by using a new scheme: modified cubic B-spline differential quadrature method (MCB-DQM. The scheme is based on differential quadrature method in which the weighting coefficients are obtained by using modified cubic B-splines as a set of basis functions. This scheme reduces the equation into a system of first-order ordinary differential equation (ODE which is solved by adopting SSP-RK43 scheme. Further, it is shown that the proposed scheme is stable. The efficiency of the proposed method is illustrated by four numerical experiments, which confirm that obtained results are in good agreement with earlier studies. This scheme is an easy, economical and efficient technique for finding numerical solutions for various kinds of (nonlinear physical models as compared to the earlier schemes.

  9. Radiology illustrated. Hepatobiliary and pancreatic radiology

    International Nuclear Information System (INIS)

    Choi, Byung Ihn

    2014-01-01

    Clear, practical guide to the diagnostic imaging of diseases of the liver, biliary tree, gallbladder, pancreas, and spleen. A wealth of carefully selected and categorized illustrations. Highlighted key points to facilitate rapid review. Aid to differential diagnosis. Radiology Illustrated: Hepatobiliary and Pancreatic Radiology is the first of two volumes that will serve as a clear, practical guide to the diagnostic imaging of abdominal diseases. This volume, devoted to diseases of the liver, biliary tree, gallbladder, pancreas, and spleen, covers congenital disorders, vascular diseases, benign and malignant tumors, and infectious conditions. Liver transplantation, evaluation of the therapeutic response of hepatocellular carcinoma, trauma, and post-treatment complications are also addressed. The book presents approximately 560 cases with more than 2100 carefully selected and categorized illustrations, along with key text messages and tables, that will allow the reader easily to recall the relevant images as an aid to differential diagnosis. At the end of each text message, key points are summarized to facilitate rapid review and learning. In addition, brief descriptions of each clinical problem are provided, followed by both common and uncommon case studies that illustrate the role of different imaging modalities, such as ultrasound, radiography, CT, and MRI.

  10. Radiology illustrated. Hepatobiliary and pancreatic radiology

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Byung Ihn (ed.) [Seoul National Univ. Hospital (Korea, Republic of). Dept. of Radiology

    2014-04-01

    Clear, practical guide to the diagnostic imaging of diseases of the liver, biliary tree, gallbladder, pancreas, and spleen. A wealth of carefully selected and categorized illustrations. Highlighted key points to facilitate rapid review. Aid to differential diagnosis. Radiology Illustrated: Hepatobiliary and Pancreatic Radiology is the first of two volumes that will serve as a clear, practical guide to the diagnostic imaging of abdominal diseases. This volume, devoted to diseases of the liver, biliary tree, gallbladder, pancreas, and spleen, covers congenital disorders, vascular diseases, benign and malignant tumors, and infectious conditions. Liver transplantation, evaluation of the therapeutic response of hepatocellular carcinoma, trauma, and post-treatment complications are also addressed. The book presents approximately 560 cases with more than 2100 carefully selected and categorized illustrations, along with key text messages and tables, that will allow the reader easily to recall the relevant images as an aid to differential diagnosis. At the end of each text message, key points are summarized to facilitate rapid review and learning. In addition, brief descriptions of each clinical problem are provided, followed by both common and uncommon case studies that illustrate the role of different imaging modalities, such as ultrasound, radiography, CT, and MRI.

  11. Adiabatic description of capture into resonance and surfatron acceleration of charged particles by electromagnetic waves.

    Science.gov (United States)

    Artemyev, A V; Neishtadt, A I; Zelenyi, L M; Vainchtein, D L

    2010-12-01

    We present an analytical and numerical study of the surfatron acceleration of nonrelativistic charged particles by electromagnetic waves. The acceleration is caused by capture of particles into resonance with one of the waves. We investigate capture for systems with one or two waves and provide conditions under which the obtained results can be applied to systems with more than two waves. In the case of a single wave, the once captured particles never leave the resonance and their velocity grows linearly with time. However, if there are two waves in the system, the upper bound of the energy gain may exist and we find the analytical value of that bound. We discuss several generalizations including the relativistic limit, different wave amplitudes, and a wide range of the waves' wavenumbers. The obtained results are used for qualitative description of some phenomena observed in the Earth's magnetosphere. © 2010 American Institute of Physics.

  12. On a New Method for Computing the Numerical Solution of Systems of Nonlinear Equations

    Directory of Open Access Journals (Sweden)

    H. Montazeri

    2012-01-01

    Full Text Available We consider a system of nonlinear equations F(x=0. A new iterative method for solving this problem numerically is suggested. The analytical discussions of the method are provided to reveal its sixth order of convergence. A discussion on the efficiency index of the contribution with comparison to the other iterative methods is also given. Finally, numerical tests illustrate the theoretical aspects using the programming package Mathematica.

  13. Almost Surely Asymptotic Stability of Numerical Solutions for Neutral Stochastic Delay Differential Equations

    Directory of Open Access Journals (Sweden)

    Zhanhua Yu

    2011-01-01

    convergence theorem. It is shown that the Euler method and the backward Euler method can reproduce the almost surely asymptotic stability of exact solutions to NSDDEs under additional conditions. Numerical examples are demonstrated to illustrate the effectiveness of our theoretical results.

  14. Capturing complex human behaviors in representative sports contexts with a single camera.

    Science.gov (United States)

    Duarte, Ricardo; Araújo, Duarte; Fernandes, Orlando; Fonseca, Cristina; Correia, Vanda; Gazimba, Vítor; Travassos, Bruno; Esteves, Pedro; Vilar, Luís; Lopes, José

    2010-01-01

    In the last years, several motion analysis methods have been developed without considering representative contexts for sports performance. The purpose of this paper was to explain and underscore a straightforward method to measure human behavior in these contexts. Procedures combining manual video tracking (with TACTO device) and bidimensional reconstruction (through direct linear transformation) using a single camera were used in order to capture kinematic data required to compute collective variable(s) and control parameter(s). These procedures were applied to a 1vs1 association football task as an illustrative subphase of team sports and will be presented in a tutorial fashion. Preliminary analysis of distance and velocity data identified a collective variable (difference between the distance of the attacker and the defender to a target defensive area) and two nested control parameters (interpersonal distance and relative velocity). Findings demonstrated that the complementary use of TACTO software and direct linear transformation permit to capture and reconstruct complex human actions in their context in a low dimensional space (information reduction).

  15. Textile Art as Illustration.

    Science.gov (United States)

    Dickman, Floyd C.

    1998-01-01

    Used in picture-book illustration, such techniques as embroidery, applique, wood-block printing, batik, and quilting reflect cultural heritages and add richly textured images to this annotated list of titles for children from preschool through junior high. (Author)

  16. The use of transparent media in medical illustration.

    Science.gov (United States)

    Winn, W M

    1978-03-01

    Transparent media, such as watercolor, acrylic, and dyes, have been used by scientific illustrators for centuries. This article gives one artist's view of the highly complex medium. Materials, techniques, short cuts, and potential problem areas are discussed. Illustrations of specific techniques and a step-by-step development of a medical illustration is provided.

  17. Trap Height Affects Capture of Lady Beetles (Coleoptera: Coccinellidae) in Pecan Orchards.

    Science.gov (United States)

    Cottrell, T E

    2017-04-01

    There is scarce information regarding the vertical stratification of predaceous Coccinellidae in tall trees. Although numerous studies have been done in orchards and forests, very few studies have assessed the occurrence of predaceous Coccinellidae high in tree canopies. The objective of this study was to examine the abundance of Coccinellidae at different heights in mature pecan, Carya illinoinensis (Wangenh.) K. Koch, orchards with tall trees. From spring through late fall during 2013 and 2014, yellow pyramidal Tedders traps were suspended in the pecan canopy at 6.1 and 12.2 m, in addition to being placed on the ground (0 m). The exotic species Harmonia axyridis and Coccinella septempunctata accounted for a high percentage of trap capture during this study. Except for Olla v-nigrum, low numbers of native species (Hippodamia convergens, Coleomegilla maculata, Cycloneda munda, Scymnus spp., and Hyperaspis spp.) were captured. However, significantly more were captured in ground traps rather than in canopy traps with the exception of O. v-nigrum. Similar to most native species, significantly more C. septempunctata were captured in ground traps than canopy traps. This contrasts sharply with H. axyridis captured similarly at all trap heights. The ability to exploit resources across vertical strata, unlike many intraguild predators, may be an underestimated factor helping to explain the invasiveness of H. axyridis. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by a US Government employee and is in the public domain in the US.

  18. Modelling of catalytic oxidation of NH3 and reduction of NO on limestone during sulphur capture

    DEFF Research Database (Denmark)

    Kiil, Søren; Bhatia, Suresh K.; Dam-Johansen, Kim

    1996-01-01

    activity with respect to each species involved. An existing particle model, the Grain-Micrograin Model, which simulates sulphur capture on limestone under oxidizing conditions is considered in the modelling. Simulation results in good qualitative agreement with experimental data are obtained here......A theoretical study of the complex transient system of simultaneous sulphur capture and catalytic reactions of N-containing compounds taking place on a single limestone particle is conducted. The numerical technique developed previously by the authors (Kiil et al. 1994) based on collocation...... for the catalytic chemistry of NH3 during simultaneous sulphur capture on a Stevns Chalk particle. The reduction of NO by NH3 over CaSO4 (which is the product of the reaction between SO2, O2 and limestone) was found to be important because this reaction could explain the change in selectivity with increased solid...

  19. Direct numerical simulation of bluff-body-stabilized premixed flames

    KAUST Repository

    Arias, Paul G.

    2014-01-10

    To enable high fidelity simulation of combustion phenomena in realistic devices, an embedded boundary method is implemented into direct numerical simulations (DNS) of reacting flows. One of the additional numerical issues associated with reacting flows is the stable treatment of the embedded boundaries in the presence of multicomponent species and reactions. The implemented method is validated in two test con gurations: a pre-mixed hydrogen/air flame stabilized in a backward-facing step configuration, and reactive flows around a square prism. The former is of interest in practical gas turbine combustor applications in which the thermo-acoustic instabilities are a strong concern, and the latter serves as a good model problem to capture the vortex shedding behind a bluff body. In addition, a reacting flow behind the square prism serves as a model for the study of flame stabilization in a micro-channel combustor. The present study utilizes fluid-cell reconstruction methods in order to capture important flame-to-solid wall interactions that are important in confined multicomponent reacting flows. Results show that the DNS with embedded boundaries can be extended to more complex geometries without loss of accuracy and the high fidelity simulation data can be used to develop and validate turbulence and combustion models for the design of practical combustion devices.

  20. Numerical verification of equilibrium chemistry software within nuclear fuel performance codes

    International Nuclear Information System (INIS)

    Piro, M.H.; Lewis, B.J.; Thompson, W.T.; Simunovic, S.; Besmann, T.M.

    2010-01-01

    A numerical tool is in an advanced state of development to compute the equilibrium compositions of phases and their proportions in multi-component systems of importance to the nuclear industry. The resulting software is being conceived for direct integration into large multi-physics fuel performance codes, particularly for providing transport source terms, material properties, and boundary conditions in heat and mass transport modules. Consequently, any numerical errors produced in equilibrium chemistry computations will be propagated in subsequent heat and mass transport calculations, thus falsely predicting nuclear fuel behaviour. The necessity for a reliable method to numerically verify chemical equilibrium computations is emphasized by the requirement to handle the very large number of elements necessary to capture the entire fission product inventory. A simple, reliable and comprehensive numerical verification method called the Gibbs Criteria is presented which can be invoked by any equilibrium chemistry solver for quality assurance purposes. (author)

  1. An Adjoint-based Numerical Method for a class of nonlinear Fokker-Planck Equations

    KAUST Repository

    Festa, Adriano; Gomes, Diogo A.; Machado Velho, Roberto

    2017-01-01

    Here, we introduce a numerical approach for a class of Fokker-Planck (FP) equations. These equations are the adjoint of the linearization of Hamilton-Jacobi (HJ) equations. Using this structure, we show how to transfer the properties of schemes for HJ equations to the FP equations. Hence, we get numerical schemes with desirable features such as positivity and mass-preservation. We illustrate this approach in examples that include mean-field games and a crowd motion model.

  2. An Adjoint-based Numerical Method for a class of nonlinear Fokker-Planck Equations

    KAUST Repository

    Festa, Adriano

    2017-03-22

    Here, we introduce a numerical approach for a class of Fokker-Planck (FP) equations. These equations are the adjoint of the linearization of Hamilton-Jacobi (HJ) equations. Using this structure, we show how to transfer the properties of schemes for HJ equations to the FP equations. Hence, we get numerical schemes with desirable features such as positivity and mass-preservation. We illustrate this approach in examples that include mean-field games and a crowd motion model.

  3. Numerical methods for the Lévy LIBOR model

    DEFF Research Database (Denmark)

    Papapantoleon, Antonis; Skovmand, David

    2010-01-01

    but the methods are generally slow. We propose an alternative approximation scheme based on Picard iterations. Our approach is similar in accuracy to the full numerical solution, but with the feature that each rate is, unlike the standard method, evolved independently of the other rates in the term structure....... This enables simultaneous calculation of derivative prices of different maturities using parallel computing. We include numerical illustrations of the accuracy and speed of our method pricing caplets.......The aim of this work is to provide fast and accurate approximation schemes for the Monte-Carlo pricing of derivatives in the L\\'evy LIBOR model of Eberlein and \\"Ozkan (2005). Standard methods can be applied to solve the stochastic differential equations of the successive LIBOR rates...

  4. Numerical Methods for the Lévy LIBOR Model

    DEFF Research Database (Denmark)

    Papapantoleon, Antonis; Skovmand, David

    are generally slow. We propose an alternative approximation scheme based on Picard iterations. Our approach is similar in accuracy to the full numerical solution, but with the feature that each rate is, unlike the standard method, evolved independently of the other rates in the term structure. This enables...... simultaneous calculation of derivative prices of different maturities using parallel computing. We include numerical illustrations of the accuracy and speed of our method pricing caplets.......The aim of this work is to provide fast and accurate approximation schemes for the Monte-Carlo pricing of derivatives in the Lévy LIBOR model of Eberlein and Özkan (2005). Standard methods can be applied to solve the stochastic differential equations of the successive LIBOR rates but the methods...

  5. A numerical method for multigroup slab-geometry discrete ordinates problems with no spatial truncation error

    International Nuclear Information System (INIS)

    Barros, R.C. de; Larsen, E.W.

    1991-01-01

    A generalization of the one-group Spectral Green's Function (SGF) method is developed for multigroup, slab-geometry discrete ordinates (S N ) problems. The multigroup SGF method is free from spatial truncation errors; it generated numerical values for the cell-edge and cell-average angular fluxes that agree with the analytic solution of the multigroup S N equations. Numerical results are given to illustrate the method's accuracy

  6. Beyond Self-Report: Emerging Methods for Capturing Individual Differences in Decision-Making Process

    Directory of Open Access Journals (Sweden)

    Brenda L Connors

    2016-03-01

    Full Text Available People vary in the way in which they approach decision making, which impacts real-world behavior. There has been a surge of interest in moving beyond reliance on self-report measures to capture such individual differences. Particular emphasis has been placed on devising and applying a range of methodologies that include experimental, neuroscience, and observational paradigms. This paper provides a selective review of recent studies that illustrate the methods and yield of these approaches in terms of generating a deeper understanding of decision-making style and the notable differences that can be found across individuals.

  7. Multi-fuel multi-product operation of IGCC power plants with carbon capture and storage (CCS)

    International Nuclear Information System (INIS)

    Cormos, Ana-Maria; Dinca, Cristian; Cormos, Calin-Cristian

    2015-01-01

    This paper investigates multi-fuel multi-product operation of IGCC plants with carbon capture and storage (CCS). The investigated plant designs co-process coal with different sorts of biomass (e.g. sawdust) and solid wastes, through gasification, leading to different decarbonised energy vectors (power, hydrogen, heat, substitute natural gas etc.) simultaneous with carbon capture. Co-gasification of coal with different renewable energy sources coupled with carbon capture will pave the way towards zero emissions power plants. The energy conversions investigated in the paper were simulated using commercial process flow modelling package (ChemCAD) in order to produce mass and energy balances necessary for the proposed evaluation. As illustrative cases, hydrogen and power co-generation and Fischer–Tropsch fuel synthesis (both with carbon capture), were presented. The case studies investigated in the paper produce a flexible ratio between power and hydrogen (in the range of 400–600 MW net electricity and 0–200 MW th hydrogen considering the lower heating value) with at least 90% carbon capture rate. Special emphasis were given to fuel selection criteria for optimisation of gasification performances (fuel blending), to the selection criteria for gasification reactor in a multi-fuel multi-product operation scenario, modelling and simulation of whole process, to thermal and power integration of processes, flexibility analysis of the energy conversion processes, in-depth techno-economic and environmental assessment etc. - Highlights: • Assessment of IGCC-based energy vectors poly-generation systems with CCS. • Optimisation of gasification performances and CO 2 emissions by fuel blending. • Multi-fuel multi-product operation of gasification plants

  8. Capturing Ridge Functions in High Dimensions from Point Queries

    KAUST Repository

    Cohen, Albert

    2011-12-21

    Constructing a good approximation to a function of many variables suffers from the "curse of dimensionality". Namely, functions on ℝ N with smoothness of order s can in general be captured with accuracy at most O(n -s/N) using linear spaces or nonlinear manifolds of dimension n. If N is large and s is not, then n has to be chosen inordinately large for good accuracy. The large value of N often precludes reasonable numerical procedures. On the other hand, there is the common belief that real world problems in high dimensions have as their solution, functions which are more amenable to numerical recovery. This has led to the introduction of models for these functions that do not depend on smoothness alone but also involve some form of variable reduction. In these models it is assumed that, although the function depends on N variables, only a small number of them are significant. Another variant of this principle is that the function lives on a low dimensional manifold. Since the dominant variables (respectively the manifold) are unknown, this leads to new problems of how to organize point queries to capture such functions. The present paper studies where to query the values of a ridge function f(x)=g(a · x) when both a∈ℝ N and g ∈ C[0,1] are unknown. We establish estimates on how well f can be approximated using these point queries under the assumptions that g ∈ C s[0,1]. We also study the role of sparsity or compressibility of a in such query problems. © 2011 Springer Science+Business Media, LLC.

  9. CO{sub 2} capture and utilization for enhanced oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Vilhelmsen, P.J.; Well, W. van; Nielsen, Charles [DONG Energy Generation, Fredericia (Denmark); Harrar, W.; Reffstrup, J. [DONG Energy Exploration and Production, Hoersholm (Denmark)

    2007-05-15

    CO{sub 2} is an international theme and the cap-and-trade systems under implementation will lead to significant alterations in the energy market and in the energy system altogether. A possible technical step to reduce atmospheric emissions is CO{sub 2} capture and the utilisation of the CO{sub 2} for Enhanced Oil Recovery (EOR). CO{sub 2} capture is to some extent a know technology but has not yet been optimised and commercialised for power plant utilisation. Correspondingly CO{sub 2} utilisation for EOR is a known method in other areas of the world where the reservoir conditions are different from those of the North Sea. For several years Elsam and Energi E2, part of DONG Energy, have worked on reducing CO{sub 2} emissions through increased efficiency at the coal-fired power plants, and this work has now been extended to also include capture and utilisation of CO{sub 2}. DONG E and P within DONG Energy has started work on the utilisation of CO{sub 2} for EOR at the company's fields in the North Sea. Based on DONG Energy's interest in working through the whole value chain from power plants to EOR utilisation in the North Sea, this paper describes our experience with CO{sub 2} capture at the trial plant CASTOR at Esbjerg power plant and the actual work of investigating and preparing the pilot test of CO{sub 2} for EOR in the North Sea. The paper also illustrates the perspectives of retrofitting the existing fleet of super critical coal-fired power plants close to the North Sea with CO{sub 2} capture and the utilisation of the CO{sub 2} for EOR in the North Sea. DONG Energy's perspective is that CO{sub 2} for EOR can contribute to materialising the vision that the central power plant can be developed into an energy refinery. The development work presented will be carried out in cooperation with leading international players and Danish universities and knowledge centres Technical University of Denmark (DTU), The Danish Geotechnical Institute (GEO) and Geological

  10. Estimating temporary emigration and breeding proportions using capture-recapture data with Pollock's robust design

    Science.gov (United States)

    Kendall, W.L.; Nichols, J.D.; Hines, J.E.

    1997-01-01

    Statistical inference for capture-recapture studies of open animal populations typically relies on the assumption that all emigration from the studied population is permanent. However, there are many instances in which this assumption is unlikely to be met. We define two general models for the process of temporary emigration, completely random and Markovian. We then consider effects of these two types of temporary emigration on Jolly-Seber (Seber 1982) estimators and on estimators arising from the full-likelihood approach of Kendall et al. (1995) to robust design data. Capture-recapture data arising from Pollock's (1982) robust design provide the basis for obtaining unbiased estimates of demographic parameters in the presence of temporary emigration and for estimating the probability of temporary emigration. We present a likelihood-based approach to dealing with temporary emigration that permits estimation under different models of temporary emigration and yields tests for completely random and Markovian emigration. In addition, we use the relationship between capture probability estimates based on closed and open models under completely random temporary emigration to derive three ad hoc estimators for the probability of temporary emigration, two of which should be especially useful in situations where capture probabilities are heterogeneous among individual animals. Ad hoc and full-likelihood estimators are illustrated for small mammal capture-recapture data sets. We believe that these models and estimators will be useful for testing hypotheses about the process of temporary emigration, for estimating demographic parameters in the presence of temporary emigration, and for estimating probabilities of temporary emigration. These latter estimates are frequently of ecological interest as indicators of animal movement and, in some sampling situations, as direct estimates of breeding probabilities and proportions.

  11. Formation of S-type planets in close binaries: scattering induced tidal capture of circumbinary planets

    Science.gov (United States)

    Gong, Yan-Xiang; Ji, Jianghui

    2018-05-01

    Although several S-type and P-type planets in binary systems were discovered in past years, S-type planets have not yet been found in close binaries with an orbital separation not more than 5 au. Recent studies suggest that S-type planets in close binaries may be detected through high-accuracy observations. However, nowadays planet formation theories imply that it is difficult for S-type planets in close binaries systems to form in situ. In this work, we extensively perform numerical simulations to explore scenarios of planet-planet scattering among circumbinary planets and subsequent tidal capture in various binary configurations, to examine whether the mechanism can play a part in producing such kind of planets. Our results show that this mechanism is robust. The maximum capture probability is ˜10%, which can be comparable to the tidal capture probability of hot Jupiters in single star systems. The capture probability is related to binary configurations, where a smaller eccentricity or a low mass ratio of the binary will lead to a larger probability of capture, and vice versa. Furthermore, we find that S-type planets with retrograde orbits can be naturally produced via capture process. These planets on retrograde orbits can help us distinguish in situ formation and post-capture origin for S-type planet in close binaries systems. The forthcoming missions (PLATO) will provide the opportunity and feasibility to detect such planets. Our work provides several suggestions for selecting target binaries in search for S-type planets in the near future.

  12. Electron correlations in single-electron capture from helium by fast protons and α particles

    International Nuclear Information System (INIS)

    Mancev, Ivan; Milojevic, Nenad

    2010-01-01

    Single-electron capture from heliumlike atomic systems by bare projectiles is investigated by means of the four-body boundary-corrected first Born approximation (CB1-4B). The effect of the dynamic electron correlation is explicitly taken into account through the complete perturbation potential. The quantum-mechanical post and prior transition amplitudes for single charge exchange encompassing symmetric and/or asymmetric collisions are derived in terms of two-dimensional real integrals in the case of the prior form and five-dimensional quadratures for the post form. An illustrative computation is performed for single-electron capture from helium by protons and α particles at intermediate and high impact energies. The role of dynamic correlations is examined as a function of increased projectile energy. The validity and utility of the proposed CB1-4B method is critically assessed in comparison with the existing experimental data for total cross sections, and excellent agreement is obtained.

  13. Muon capture on Ni isotopes, projected QRPA, and CVC hypothesis

    International Nuclear Information System (INIS)

    Samana, Arturo R.; Sande, Danilo; Krmpotic, Francisco; Universidad Nacional de La Plata

    2011-01-01

    In recent years we have developed a novel formalism for the weak interaction processes, obtaining new expressions for the transition rates, which greatly facilitate numerical calculations, for both neutrino-nucleus reactions and muon capture, allowing us to use very large configuration spaces and to evaluate the quasielastic 12 C (ν, μ - ) 12 N cross section at energies of the order of 1 GeV, which are measured in the MiniBooNE experiment. Our formulation includes for the first time the consequences of the explicit violation of the conserved vector current (CVC) hypothesis by the Coulomb field. We have also shown that the particle number projection procedure within the quasiparticle random phase approximation (QRPA) is important in describing the exclusive (ground-state) properties of 12 B and 12 N as well as the muon capture rate and the neutrino nucleus cross section in 56 Fe. In this work, we analyze in a quantitative way the consequences of the CVC violation on the muon capture rates in Ni isotopes (for which are available the experimental data) using both the standard QRPA and the projected QRPA (PQRPA). The last one is the only RPA model that treats the Pauli Principle correctly, and we demonstrate that the number projection procedure is important not only for light nuclei but also for medium heavy ones that were studied here. (author)

  14. Crédit des illustrations

    OpenAIRE

    2017-01-01

    Illustration de couverture : Lyon, cathédrale Saint-Jean, culée de l’arc-boutant 2/3 : David (XIIIe siècle) surgissant de l’échafaudage (XXIe siècle). Photo Jean-Pierre Gobillot. Illustration de la quatrième de couverture : Lyon, cathédrale Saint-Jean, arcature extérieure de l’abside, chapiteau central. Dessin Ghislaine Macabéo. Photos Jean-Pierre Gobillot : fig. 1, 2, 10, 13, 14, 16, 23, 28, 29, 34, 35, 36, 37, 40, 41, 46, 54, 55, 56, 59, 60, 67, 76a, 78, 80, 82, 83, 88, 90, 97, 105, 106, 11...

  15. International Winter Workshop on Differential Equations and Numerical Analysis

    CERN Document Server

    Miller, John; Narasimhan, Ramanujam; Mathiazhagan, Paramasivam; Victor, Franklin

    2016-01-01

    This book offers an ideal introduction to singular perturbation problems, and a valuable guide for researchers in the field of differential equations. It also includes chapters on new contributions to both fields: differential equations and singular perturbation problems. Written by experts who are active researchers in the related fields, the book serves as a comprehensive source of information on the underlying ideas in the construction of numerical methods to address different classes of problems with solutions of different behaviors, which will ultimately help researchers to design and assess numerical methods for solving new problems. All the chapters presented in the volume are complemented by illustrations in the form of tables and graphs.

  16. Stability of numerical method for semi-linear stochastic pantograph differential equations

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    2016-01-01

    Full Text Available Abstract As a particular expression of stochastic delay differential equations, stochastic pantograph differential equations have been widely used in nonlinear dynamics, quantum mechanics, and electrodynamics. In this paper, we mainly study the stability of analytical solutions and numerical solutions of semi-linear stochastic pantograph differential equations. Some suitable conditions for the mean-square stability of an analytical solution are obtained. Then we proved the general mean-square stability of the exponential Euler method for a numerical solution of semi-linear stochastic pantograph differential equations, that is, if an analytical solution is stable, then the exponential Euler method applied to the system is mean-square stable for arbitrary step-size h > 0 $h>0$ . Numerical examples further illustrate the obtained theoretical results.

  17. Multilevel Monte Carlo Approaches for Numerical Homogenization

    KAUST Repository

    Efendiev, Yalchin R.

    2015-10-01

    In this article, we study the application of multilevel Monte Carlo (MLMC) approaches to numerical random homogenization. Our objective is to compute the expectation of some functionals of the homogenized coefficients, or of the homogenized solutions. This is accomplished within MLMC by considering different sizes of representative volumes (RVEs). Many inexpensive computations with the smallest RVE size are combined with fewer expensive computations performed on larger RVEs. Likewise, when it comes to homogenized solutions, different levels of coarse-grid meshes are used to solve the homogenized equation. We show that, by carefully selecting the number of realizations at each level, we can achieve a speed-up in the computations in comparison to a standard Monte Carlo method. Numerical results are presented for both one-dimensional and two-dimensional test-cases that illustrate the efficiency of the approach.

  18. The National Carbon Capture Center at the Power Systems Development Facility

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2014-12-30

    The National Carbon Capture Center (NCCC) at the Power Systems Development Facility supports the Department of Energy (DOE) goal of promoting the United States’ energy security through reliable, clean, and affordable energy produced from coal. Work at the NCCC supports the development of new power technologies and the continued operation of conventional power plants under CO2 emission constraints. The NCCC includes adaptable slipstreams that allow technology development of CO2 capture concepts using coal-derived syngas and flue gas in industrial settings. Because of the ability to operate under a wide range of flow rates and process conditions, research at the NCCC can effectively evaluate technologies at various levels of maturity and accelerate their development path to commercialization. During its first contract period, from October 1, 2008, through December 30, 2014, the NCCC designed, constructed, and began operation of the Post-Combustion Carbon Capture Center (PC4). Testing of CO2 capture technologies commenced in 2011, and through the end of the contract period, more than 25,000 hours of testing had been achieved, supporting a variety of technology developers. Technologies tested included advanced solvents, enzymes, membranes, sorbents, and associated systems. The NCCC continued operation of the existing gasification facilities, which have been in operation since 1996, to support the advancement of technologies for next-generation gasification processes and pre-combustion CO2 capture. The gasification process operated for 13 test runs, supporting over 30,000 hours combined of both gasification and pre-combustion technology developer testing. Throughout the contract period, the NCCC incorporated numerous modifications to the facilities to accommodate technology developers and increase test capabilities. Preparations for further testing were ongoing to continue advancement of the most promising technologies for

  19. Hartree-Fock-Bogoliubov model: a theoretical and numerical perspective

    International Nuclear Information System (INIS)

    Paul, S.

    2012-01-01

    This work is devoted to the theoretical and numerical study of Hartree-Fock-Bogoliubov (HFB) theory for attractive quantum systems, which is one of the main methods in nuclear physics. We first present the model and its main properties, and then explain how to get numerical solutions. We prove some convergence results, in particular for the simple fixed point algorithm (sometimes called Roothaan). We show that it converges, or oscillates between two states, none of them being a solution. This generalizes to the HFB case previous results of Cances and Le Bris for the simpler Hartree-Fock model in the repulsive case. Following these authors, we also propose a relaxed constraint algorithm for which convergence is guaranteed. In the last part of the thesis, we illustrate the behavior of these algorithms by some numerical experiments. We first consider a system where the particles only interact through the Newton potential. Our numerical results show that the pairing matrix never vanishes, a fact that has not yet been proved rigorously. We then study a very simplified model for protons and neutrons in a nucleus. (author)

  20. Stable Numerical Approach for Fractional Delay Differential Equations

    Science.gov (United States)

    Singh, Harendra; Pandey, Rajesh K.; Baleanu, D.

    2017-12-01

    In this paper, we present a new stable numerical approach based on the operational matrix of integration of Jacobi polynomials for solving fractional delay differential equations (FDDEs). The operational matrix approach converts the FDDE into a system of linear equations, and hence the numerical solution is obtained by solving the linear system. The error analysis of the proposed method is also established. Further, a comparative study of the approximate solutions is provided for the test examples of the FDDE by varying the values of the parameters in the Jacobi polynomials. As in special case, the Jacobi polynomials reduce to the well-known polynomials such as (1) Legendre polynomial, (2) Chebyshev polynomial of second kind, (3) Chebyshev polynomial of third and (4) Chebyshev polynomial of fourth kind respectively. Maximum absolute error and root mean square error are calculated for the illustrated examples and presented in form of tables for the comparison purpose. Numerical stability of the presented method with respect to all four kind of polynomials are discussed. Further, the obtained numerical results are compared with some known methods from the literature and it is observed that obtained results from the proposed method is better than these methods.

  1. Numerical method for solving linear Fredholm fuzzy integral equations of the second kind

    Energy Technology Data Exchange (ETDEWEB)

    Abbasbandy, S. [Department of Mathematics, Imam Khomeini International University, P.O. Box 288, Ghazvin 34194 (Iran, Islamic Republic of)]. E-mail: saeid@abbasbandy.com; Babolian, E. [Faculty of Mathematical Sciences and Computer Engineering, Teacher Training University, Tehran 15618 (Iran, Islamic Republic of); Alavi, M. [Department of Mathematics, Arak Branch, Islamic Azad University, Arak 38135 (Iran, Islamic Republic of)

    2007-01-15

    In this paper we use parametric form of fuzzy number and convert a linear fuzzy Fredholm integral equation to two linear system of integral equation of the second kind in crisp case. We can use one of the numerical method such as Nystrom and find the approximation solution of the system and hence obtain an approximation for fuzzy solution of the linear fuzzy Fredholm integral equations of the second kind. The proposed method is illustrated by solving some numerical examples.

  2. Capture of impurity atoms by defects and the distribution of the complexes under ion bormbardment of growing films

    International Nuclear Information System (INIS)

    Radzhabov, T.D.; Iskanderova, Z.A.; Arutyunova, E.O.; Samigulin, K.R.

    1982-01-01

    Theoretical study of capture of impurity gas atoms with defects during ion introduction of the impurity in the process of film growth with simultaneous diffusion has been carried out. Concentration profiles of forned impurity-defect complexes have been calculated analytically and numerically by means of a computer in film depth and in a substrate; basic peculiarities of impurity component formation captured with defects in a wide range of changing basic experimental parameters have been revealed. Effect of impurity capture with defects on amount and distribution of total concentration of impurity atoms and intensity of complete absorption of bombarding ions in films have been analyzed. Shown is a possibility for producing films with a high concentration level and almost uniform distribution of the impurity-defect complexes for real, achievable an experiment, values of process parameters as well as a possibility for increasing complete absorption of gaseous impurity wiht concentration growth of capture defects-traps

  3. Numerical calculation of two-phase flows

    International Nuclear Information System (INIS)

    Travis, J.R.; Harlow, F.H.; Amsden, A.A.

    1975-06-01

    The theoretical study of time-varying two-phase flow problems in several space dimensions introduces such a complicated set of coupled nonlinear partial differential equations that numerical solution procedures for high-speed computers are required in almost all but the simplest examples. Efficient attainment of realistic solutions for practical problems requires a finite- difference formulation that is simultaneously implicit in the treatment of mass convection, equations of state, and the momentum coupling between phases. Such a method is described, the equations on which it is based are discussed, and its properties are illustrated by means of examples. In particular, the capability for calculating physical instabilities and other time-varying dynamics, at the same time avoiding numerical instability is emphasized. The computer code is applicable to problems in reactor safety analysis, the dynamics of fluidized dust beds, raindrops or aerosol transport, and a variety of similar circumstances, including the effects of phase transitions and the release of latent heat or chemical energy. (U.S.)

  4. Theoretical stability in coefficient inverse problems for general hyperbolic equations with numerical reconstruction

    Science.gov (United States)

    Yu, Jie; Liu, Yikan; Yamamoto, Masahiro

    2018-04-01

    In this article, we investigate the determination of the spatial component in the time-dependent second order coefficient of a hyperbolic equation from both theoretical and numerical aspects. By the Carleman estimates for general hyperbolic operators and an auxiliary Carleman estimate, we establish local Hölder stability with either partial boundary or interior measurements under certain geometrical conditions. For numerical reconstruction, we minimize a Tikhonov functional which penalizes the gradient of the unknown function. Based on the resulting variational equation, we design an iteration method which is updated by solving a Poisson equation at each step. One-dimensional prototype examples illustrate the numerical performance of the proposed iteration.

  5. Unconditionally energy stable numerical schemes for phase-field vesicle membrane model

    Science.gov (United States)

    Guillén-González, F.; Tierra, G.

    2018-02-01

    Numerical schemes to simulate the deformation of vesicles membranes via minimizing the bending energy have been widely studied in recent times due to its connection with many biological motivated problems. In this work we propose a new unconditionally energy stable numerical scheme for a vesicle membrane model that satisfies exactly the conservation of volume constraint and penalizes the surface area constraint. Moreover, we extend these ideas to present an unconditionally energy stable splitting scheme decoupling the interaction of the vesicle with a surrounding fluid. Finally, the well behavior of the proposed schemes are illustrated through several computational experiments.

  6. Numerical Investigation of Corrugated Wire Mesh Laminate

    Directory of Open Access Journals (Sweden)

    Jeongho Choi

    2013-01-01

    Full Text Available The aim of this work is to develop a numerical model of Corrugated Wire Mesh Laminate (CWML capturing all its complexities such as nonlinear material properties, nonlinear geometry and large deformation behaviour, and frictional behaviour. Development of such a model will facilitate numerical simulation of the mechanical behaviour of the wire mesh structure under various types of loading as well as the variation of the CWML configuration parameters to tailor its mechanical properties to suit the intended application. Starting with a single strand truss model consisting of four waves with a bilinear stress-strain model to represent the plastic behaviour of stainless steel, the finite element model is gradually built up to study single-layer structures with 18 strands of corrugated wire meshes consistency and double- and quadruple-layered laminates with alternating crossply orientations. The compressive behaviour of the CWML model is simulated using contact elements to model friction and is compared to the load-deflection behaviour determined experimentally in uniaxial compression tests. The numerical model of the CWML is then employed to conduct the aim of establishing the upper and lower bounds of stiffness and load capacity achievable by such structures.

  7. Small Particles Intact Capture Experiment (SPICE)

    Science.gov (United States)

    Nishioka, Ken-Ji; Carle, G. C.; Bunch, T. E.; Mendez, David J.; Ryder, J. T.

    1994-01-01

    The Small Particles Intact Capture Experiment (SPICE) will develop technologies and engineering techniques necessary to capture nearly intact, uncontaminated cosmic and interplanetary dust particles (IDP's). Successful capture of such particles will benefit the exobiology and planetary science communities by providing particulate samples that may have survived unaltered since the formation of the solar system. Characterization of these particles may contribute fundamental data to our knowledge of how these particles could have formed into our planet Earth and, perhaps, contributed to the beginnings of life. The term 'uncontaminated' means that captured cosmic and IDP particles are free of organic contamination from the capture process and the term 'nearly intact capture' means that their chemical and elemental components are not materially altered during capture. The key to capturing cosmic and IDP particles that are organic-contamination free and nearly intact is the capture medium. Initial screening of capture media included organic foams, multiple thin foil layers, and aerogel (a silica gel); but, with the exception of aerogel, the requirements of no contamination or nearly intact capture were not met. To ensure no contamination of particles in the capture process, high-purity aerogel was chosen. High-purity aerogel results in high clarity (visual clearness), a useful quality in detection and recovery of embedded captured particles from the aerogel. P. Tsou at the Jet Propulsion Laboratory (JPL) originally described the use of aerogel for this purpose and reported laboratory test results. He has flown aerogel as a 'GAS-can Lid' payload on STS-47 and is evaluating the results. The Timeband Capture Cell Experiment (TICCE), a Eureca 1 experiment, is also flying aerogel and is scheduled for recovery in late April.

  8. Laser capture microdissection: Arcturus(XT) infrared capture and UV cutting methods.

    Science.gov (United States)

    Gallagher, Rosa I; Blakely, Steven R; Liotta, Lance A; Espina, Virginia

    2012-01-01

    Laser capture microdissection (LCM) is a technique that allows the precise procurement of enriched cell populations from a heterogeneous tissue under direct microscopic visualization. LCM can be used to harvest the cells of interest directly or can be used to isolate specific cells by ablating the unwanted cells, resulting in histologically enriched cell populations. The fundamental components of laser microdissection technology are (a) visualization of the cells of interest via microscopy, (b) transfer of laser energy to a thermolabile polymer with either the formation of a polymer-cell composite (capture method) or transfer of laser energy via an ultraviolet laser to photovolatize a region of tissue (cutting method), and (c) removal of cells of interest from the heterogeneous tissue section. Laser energy supplied by LCM instruments can be infrared (810 nm) or ultraviolet (355 nm). Infrared lasers melt thermolabile polymers for cell capture, whereas ultraviolet lasers ablate cells for either removal of unwanted cells or excision of a defined area of cells. LCM technology is applicable to an array of applications including mass spectrometry, DNA genotyping and loss-of-heterozygosity analysis, RNA transcript profiling, cDNA library generation, proteomics discovery, and signal kinase pathway profiling. This chapter describes the unique features of the Arcturus(XT) laser capture microdissection instrument, which incorporates both infrared capture and ultraviolet cutting technology in one instrument, using a proteomic downstream assay as a model.

  9. Relaxation and Numerical Approximation of a Two-Fluid Two-Pressure Diphasic Model

    International Nuclear Information System (INIS)

    Ambroso, A.; Chalons, Ch.; Galie, Th.; Chalons, Ch.; Coquel, F.; Coquel, F.

    2009-01-01

    This paper is concerned with the numerical approximation of the solutions of a two-fluid two-pressure model used in the modelling of two-phase flows. We present a relaxation strategy for easily dealing with both the nonlinearities associated with the pressure laws and the nonconservative terms that are inherently present in the set of convective equations and that couple the two phases. In particular, the proposed approximate Riemann solver is given by explicit formulas, preserves the natural phase space, and exactly captures the coupling waves between the two phases. Numerical evidences are given to corroborate the validity of our approach. (authors)

  10. Study on keV-neutron capture cross sections and capture γ-ray spectra of 117,119Sn

    International Nuclear Information System (INIS)

    Nishiyama, J.; Igashira, M.; Ohsaki, T.; Kim, G.N.; Chung, W.C.; Ro, T.I.

    2006-01-01

    The capture cross sections and capture γ-ray spectra of 117,119 Sn were measured in an incident neutron energy region from 10 to 100 keV and at 570 keV, using a 1.5-ns pulsed neutron source by the 7 Li(p,n) 7 Be reaction and a large anti-Compton NaI(Tl) γ-ray spectrometer. A pulse-height weighting technique was applied to observed capture γ-ray pulse-height spectra to derive capture yields. The capture cross sections of 117,119 Sn were obtained with the error of about 5% by using the standard capture cross sections of 197 Au. The present cross sections were compared with previous experimental data and the evaluated values in JENDL-3.3 and ENDF/B-VI. The capture γ-ray spectra of 117,119 Sn were derived by unfolding the observed capture γ-ray pulse-height spectra. The calculations of capture cross sections and capture γ-ray spectra of 117,119 Sn were performed with the EMPIRE-II code. The calculated results were compared with the present experimental ones. (author)

  11. 7th International Conference on Hyperbolic Problems Theory, Numerics, Applications

    CERN Document Server

    Jeltsch, Rolf

    1999-01-01

    These proceedings contain, in two volumes, approximately one hundred papers presented at the conference on hyperbolic problems, which has focused to a large extent on the laws of nonlinear hyperbolic conservation. Two-fifths of the papers are devoted to mathematical aspects such as global existence, uniqueness, asymptotic behavior such as large time stability, stability and instabilities of waves and structures, various limits of the solution, the Riemann problem and so on. Roughly the same number of articles are devoted to numerical analysis, for example stability and convergence of numerical schemes, as well as schemes with special desired properties such as shock capturing, interface fitting and high-order approximations to multidimensional systems. The results in these contributions, both theoretical and numerical, encompass a wide range of applications such as nonlinear waves in solids, various computational fluid dynamics from small-scale combustion to relativistic astrophysical problems, multiphase phe...

  12. Symbolic-Numeric Integration of the Dynamical Cosserat Equations

    KAUST Repository

    Lyakhov, Dmitry A.

    2017-08-29

    We devise a symbolic-numeric approach to the integration of the dynamical part of the Cosserat equations, a system of nonlinear partial differential equations describing the mechanical behavior of slender structures, like fibers and rods. This is based on our previous results on the construction of a closed form general solution to the kinematic part of the Cosserat system. Our approach combines methods of numerical exponential integration and symbolic integration of the intermediate system of nonlinear ordinary differential equations describing the dynamics of one of the arbitrary vector-functions in the general solution of the kinematic part in terms of the module of the twist vector-function. We present an experimental comparison with the well-established generalized \\\\alpha -method illustrating the computational efficiency of our approach for problems in structural mechanics.

  13. Symbolic-Numeric Integration of the Dynamical Cosserat Equations

    KAUST Repository

    Lyakhov, Dmitry A.; Gerdt, Vladimir P.; Weber, Andreas G.; Michels, Dominik L.

    2017-01-01

    We devise a symbolic-numeric approach to the integration of the dynamical part of the Cosserat equations, a system of nonlinear partial differential equations describing the mechanical behavior of slender structures, like fibers and rods. This is based on our previous results on the construction of a closed form general solution to the kinematic part of the Cosserat system. Our approach combines methods of numerical exponential integration and symbolic integration of the intermediate system of nonlinear ordinary differential equations describing the dynamics of one of the arbitrary vector-functions in the general solution of the kinematic part in terms of the module of the twist vector-function. We present an experimental comparison with the well-established generalized \\alpha -method illustrating the computational efficiency of our approach for problems in structural mechanics.

  14. Modeling and optimization of CO2 capture processes by chemical absorption

    International Nuclear Information System (INIS)

    Neveux, Thibaut

    2013-01-01

    CO 2 capture processes by chemical absorption lead to a large energy penalty on efficiency of coal-fired power plants, establishing one of the main bottleneck to its industrial deployment. The objective of this thesis is the development and validation of a global methodology, allowing the precise evaluation of the potential of a given amine capture process. Characteristic phenomena of chemical absorption have been thoroughly studied and represented with state-of-the-art models. The e-UNIQUAC model has been used to describe vapor-liquid and chemical equilibria of electrolyte solutions and the model parameters have been identified for four solvents. A rate-based formulation has been adopted for the representation of chemically enhanced heat and mass transfer in columns. The absorption and stripping models have been successfully validated against experimental data from an industrial and a laboratory pilot plants. The influence of the numerous phenomena has been investigated in order to highlight the most limiting ones. A methodology has been proposed to evaluate the total energy penalty resulting from the implementation of a capture process on an advanced supercritical coal-fired power plant, including thermal and electric consumptions. Then, the simulation and process evaluation environments have been coupled with a non-linear optimization algorithm in order to find optimal operating and design parameters with respect to energetic and economic performances. This methodology has been applied to optimize five process flow schemes operating with an monoethanolamine aqueous solution at 30% by weight: the conventional flow scheme and four process modifications. The performance comparison showed that process modifications using a heat pump effect give the best gains. The use of technical-economic analysis as an evaluation criterion of a process performance, coupled with a optimization algorithm, has proved its capability to find values for the numerous operating and design

  15. Nonoscillatory shock capturing scheme using flux limited dissipation

    International Nuclear Information System (INIS)

    Jameson, A.

    1985-01-01

    A method for modifying the third order dissipative terms by the introduction of flux limiters is proposed. The first order dissipative terms can then be eliminated entirely, and in the case of a scalar conservation law the scheme is converted into a total variation diminishing scheme provided that an appropriate value is chosen for the dissipative coefficient. Particular attention is given to: (1) the treatment of the scalar conservation law; (2) the treatment of the Euler equations for inviscid compressible flow; (3) the boundary conditions; and (4) multistage time stepping and multigrid schemes. Numerical results for transonic flows suggest that a central difference scheme augmented by flux limited dissipative terms can lead to an effective nonoscillatory shock capturing method. 20 references

  16. DynEarthSol3D: numerical studies of basal crevasses and calving blocks

    Science.gov (United States)

    Logan, E.; Lavier, L. L.; Choi, E.; Tan, E.; Catania, G. A.

    2014-12-01

    DynEarthSol3D (DES) is a thermomechanical model for the simulation of dynamic ice flow. We present the application of DES toward two case studies - basal crevasses and calving blocks - to illustrate the potential of the model to aid in understanding calving processes. Among the advantages of using DES are: its unstructured meshes which adaptively resolve zones of high interest; its use of multiple rheologies to simulate different types of dynamic behavior; and its explicit and parallel numerical core which both make the implementation of different boundary conditions easy and the model highly scalable. We examine the initiation and development of both basal crevasses and calving blocks through time using visco-elasto-plastic rheology. Employing a brittle-to-ductile transition zone (BDTZ) based on local strain rate shows that the style and development of brittle features like crevasses differs markedly on the rheological parameters. Brittle and ductile behavior are captured by Mohr-Coulomb elastoplasticity and Maxwell viscoelasticity, respectively. We explore the parameter spaces which define these rheologies (including temperature) as well as the BDTZ threshold (shown in the literature as 10-7 Pa s), using time-to-failure as a metric for accuracy within the model. As the time it takes for a block of ice to fail can determine an iceberg's size, this work has implications for calving laws.

  17. Numerical and adaptive grid methods for ideal magnetohydrodynamics

    Science.gov (United States)

    Loring, Burlen

    2008-02-01

    In this thesis numerical finite difference methods for ideal magnetohydrodynamics(MHD) are investigated. A review of the relevant physics, essential for interpreting the results of numerical solutions and constructing validation cases, is presented. This review includes a discusion of the propagation of small amplitude waves in the MHD system as well as a thorough discussion of MHD shocks, contacts and rarefactions and how they can be piece together to obtain a solutions to the MHD Riemann problem. Numerical issues relevant to the MHD system such as: the loss of nonlinear numerical stability in the presence of discontinuous solutions, the introduction of spurious forces due to the growth of the divergence of the magnetic flux density, the loss of pressure positivity, and the effects of non-conservative numerical methods are discussed, along with the practical approaches which can be used to remedy or minimize the negative consequences of each. The use of block structured adaptive mesh refinement is investigated in the context of a divergence free MHD code. A new method for conserving magnetic flux across AMR grid interfaces is developed and a detailed discussion of our implementation of this method using the CHOMBO AMR framework is given. A preliminary validation of the new method for conserving magnetic flux density across AMR grid interfaces illustrates that the method works. Finally a number of code validation cases are examined spurring a discussion of the strengths and weaknesses of the numerics employed.

  18. In the Artist's Studio with L'Illustration

    Directory of Open Access Journals (Sweden)

    Esner, Rachel

    2013-03-01

    Full Text Available This article explores the two series of visits to the artist's studio that appeared in the famed French illustrated magazine L'Illustration in the 1850s and in 1886. An in-depth examination of both the texts and images reveals the verbal and visual tropes used to characterize the artists and their spaces, linking these to broader notions of "the artist" – his moral characteristics, behaviors, and artistic practice – as well as to the politics of the art world and the (bourgeois ideology of L'Illustration. The aim is to uncover not only the language but also the mechanics of the "mediatization" of the image of the artist in this crucial period.

  19. Computational evaluation of metal-organic frameworks for carbon dioxide capture

    Science.gov (United States)

    Yu, Jiamei

    Metal-organic frameworks (MOFs), a new class of porous solids comprised of metal-containing nodes linked by organic ligands, have become promising materials for gas separations. In particular, their flexible chemistry makes them attractive for CO2 capture from flue gas streams in post-combustion plants. Although numerous efforts have been exerted on the investigation of MOFs for CO2 capture, the exploration of the effects from coexisting components present in very dilute proportions in flue gases is limited because of the experimental difficulty to determine the coadsorption of CO2 with trace components. In this regard, molecular simulations show superiority. In this study, molecular simulations are used to estimate the influence of impurities: water, O2, and SO2 on post-combustion CO2 capture in MOFs. Firstly, two MOFs with coordinatively unsaturated metal sites (CUMs), HKUST-1 and Mg-MOF-74 are explored. Increase of CO 2 adsorption is observed for hydrated HKUST-1; on the contrary, the opposite water adsorption behavior is observed in hydrated Mg-MOF-74, leading to decrease of CO2 adsorption. Further, water effects on CO 2 capture in M-HKUST1 (M = Mg, Zn, Co, Ni) are evaluated to test whether comparing the binding energy could be a general method to evaluate water effects in MOFs with CUMs. It is found that the method works well for Zn-, Co-, and Ni-HKUST1 but partially for Mg-HKUST1. In addition, the effects of O2 and SO2 on CO2 capture in MOFs are also investigated for the first time, showing that the effects of O2 may be negligible but SO2 has negative effects in the CO 2 capture process in HKUST-1 systems. Secondly, the influences of water on CO2 capture in three UiO-66 MOFs with functional groups, --NH2, --OH and --Br are explored, respectively. For UiO-66-NH2 and -OH, the presence of water lowers CO2 adsorption significantly; in contrast, water shows much smaller effects in UiO-66-Br. Moreover, the presence of SO 2 decreases water adsorption but enhances CO

  20. Numerical simulation of superelastic shape memory alloys subjected to dynamic loads

    International Nuclear Information System (INIS)

    Cismaşiu, Corneliu; Amarante dos Santos, Filipe P

    2008-01-01

    Superelasticity, a unique property of shape memory alloys (SMAs), allows the material to recover after withstanding large deformations. This recovery takes place without any residual strains, while dissipating a considerable amount of energy. This property makes SMAs particularly suitable for applications in vibration control devices. Numerical models, calibrated with experimental laboratory tests from the literature, are used to investigate the dynamic response of three vibration control devices, built up of austenitic superelastic wires. The energy dissipation and re-centering capabilities, important features of these devices, are clearly illustrated by the numerical tests. Their sensitivity to ambient temperature and strain rate is also addressed. Finally, one of these devices is tested as a seismic passive vibration control system in a simplified numerical model of a railway viaduct, subjected to different ground accelerations

  1. Marker-Free Human Motion Capture

    DEFF Research Database (Denmark)

    Grest, Daniel

    Human Motion Capture is a widely used technique to obtain motion data for animation of virtual characters. Commercial optical motion capture systems are marker-based. This book is about marker-free motion capture and its possibilities to acquire motion from a single viewing direction. The focus...

  2. Contributions to reinforced concrete structures numerical simulations

    International Nuclear Information System (INIS)

    Badel, P.B.

    2001-07-01

    In order to be able to carry out simulations of reinforced concrete structures, it is necessary to know two aspects: the behaviour laws have to reflect the complex behaviour of concrete and a numerical environment has to be developed in order to avoid to the user difficulties due to the softening nature of the behaviour. This work deals with these two subjects. After an accurate estimation of two behaviour models (micro-plan and mesoscopic models), two damage models (the first one using a scalar variable, the other one a tensorial damage of the 2 order) are proposed. These two models belong to the framework of generalized standard materials, which renders their numerical integration easy and efficient. A method of load control is developed in order to make easier the convergence of the calculations. At last, simulations of industrial structures illustrate the efficiency of the method. (O.M.)

  3. High Status Men (but Not Women Capture the Eye of the Beholder

    Directory of Open Access Journals (Sweden)

    C. Nathan DeWall

    2008-04-01

    Full Text Available Two studies tested the hypothesis that people attend preferentially to high status men (but not women. Participants overestimated the frequency of high status men in rapidly presented arrays (Experiment 1 and fixated their visual attention on high status men in an eye-tracking study (Experiment 2. Neither study showed any evidence of preferential attention to high status women, but there was evidence that physically attractive women captured attention. The results from both studies support evolutionary theories regarding differential prioritization of social status and physical attractiveness in men versus women. These findings illustrate how examination of early-in-the-stream social cognition can provide useful insights into the adapted mind.

  4. Stimulus-driven capture and contingent capture

    NARCIS (Netherlands)

    Theeuwes, J.; Olivers, C.N.L.; Belopolsky, A.V.

    2010-01-01

    Whether or not certain physical events can capture attention has been one of the most debated issues in the study of attention. This discussion is concerned with how goal-directed and stimulus-driven processes interact in perception and cognition. On one extreme of the spectrum is the idea that

  5. Balancing of linkages and robot manipulators advanced methods with illustrative examples

    CERN Document Server

    Arakelian, Vigen

    2015-01-01

    In this book advanced balancing methods for planar and spatial linkages, hand operated and automatic robot manipulators are presented. It is organized into three main parts and eight chapters. The main parts are the introduction to balancing, the balancing of linkages and the balancing of robot manipulators. The review of state-of-the-art literature including more than 500 references discloses particularities of shaking force/moment balancing and gravity compensation methods. Then new methods for balancing of linkages are considered. Methods provided in the second part of the book deal with the partial and complete shaking force/moment balancing of various linkages. A new field for balancing methods applications is the design of mechanical systems for fast manipulation. Special attention is given to the shaking force/moment balancing of robot manipulators. Gravity balancing methods are also discussed. The suggested balancing methods are illustrated by numerous examples.

  6. Sinking, merging and stationary plumes in a coupled chemotaxis-fluid model: a high-resolution numerical approach

    KAUST Repository

    Chertock, A.; Fellner, K.; Kurganov, A.; Lorz, A.; Markowich, P. A.

    2012-01-01

    examples, which illustrate (i) the formation of sinking plumes, (ii) the possible merging of neighbouring plumes and (iii) the convergence towards numerically stable stationary plumes. The examples with stable stationary plumes show how the surface

  7. Resource capture by single leaves

    Energy Technology Data Exchange (ETDEWEB)

    Long, S.P.

    1992-05-01

    Leaves show a variety of strategies for maximizing CO{sub 2} and light capture. These are more meaningfully explained if they are considered in the context of maximizing capture relative to the utilization of water, nutrients and carbohydrates reserves. There is considerable variation between crops in their efficiency of CO{sub 2} and light capture at the leaf level. Understanding of these mechanisms indicate some ways in which efficiency of resource capture could be level cannot be meaningfully considered without simultaneous understanding of implications at the canopy level. 36 refs., 5 figs., 1 tab.

  8. Mercury's capture into the 3/2 spin-orbit resonance as a result of its chaotic dynamics.

    Science.gov (United States)

    Correia, Alexandre C M; Laskar, Jacques

    2004-06-24

    Mercury is locked into a 3/2 spin-orbit resonance where it rotates three times on its axis for every two orbits around the sun. The stability of this equilibrium state is well established, but our understanding of how this state initially arose remains unsatisfactory. Unless one uses an unrealistic tidal model with constant torques (which cannot account for the observed damping of the libration of the planet) the computed probability of capture into 3/2 resonance is very low (about 7 per cent). This led to the proposal that core-mantle friction may have increased the capture probability, but such a process requires very specific values of the core viscosity. Here we show that the chaotic evolution of Mercury's orbit can drive its eccentricity beyond 0.325 during the planet's history, which very efficiently leads to its capture into the 3/2 resonance. In our numerical integrations of 1,000 orbits of Mercury over 4 Gyr, capture into the 3/2 spin-orbit resonant state was the most probable final outcome of the planet's evolution, occurring 55.4 per cent of the time.

  9. Bringing Life to Illustration and Illustrating the World in Movement through Visual Literacy

    DEFF Research Database (Denmark)

    Carpe Pérez, Inmaculada Concepción; Pedersen, Hanne

    2016-01-01

    “If a picture is worth a thousand words” as Arthur Brisbane said, journalist of the New York Times in 1911 Fig.1 How many words would equal the hundreds of frames containing in an animation? In this equation as any other, illustration and animation are complex visual expressions, full of shapes c...

  10. Measurement of keV-neutron capture cross sections and capture gamma-ray spectra of Er isotopes

    International Nuclear Information System (INIS)

    Harun-Ar-Rashid, A.K.M.; Igashira, Masayuki; Ohsaki, Toshiro

    2000-01-01

    Neutron capture cross sections and capture γ-ray spectra of 166,167, 168 Er were measured in the energy region of 10 to 550 keV. The measurements were performed with a pulsed 7 Li(p,n) 7 Be neutron source and a large anti-Compton NaI(Tl) γ-ray spectrometer. A pulse-height weighting technique and the standard capture cross sections of gold were used to derive the capture cross sections. The errors of the derived cross sections were about 5%. The present results were compared with other measurements and evaluations. The observed capture γ-ray pulse-height spectra were unfolded to obtain the corresponding γ-ray spectra. An anomalous shoulder was observed around 3 MeV in each of the capture γ-ray spectra. (author)

  11. Adaptation illustrations: Chapter 4

    Science.gov (United States)

    Maria Janowiak; Patricia Butler; Chris Swanston; Matt St. Pierre; Linda. Parker

    2012-01-01

    In this chapter, we demonstrate how the Adaptation Workbook (Chapter 3) can be used with the Adaptation Strategies and Approaches (Chapter 2) to develop adaptation tactics for two real-world management issues. The two illustrations in this chapter are intended to provide helpful tips to managers completing the Adaptation Workbook, as well as to show how the anticipated...

  12. Numerical analysis of the big bounce in loop quantum cosmology

    International Nuclear Information System (INIS)

    Laguna, Pablo

    2007-01-01

    Loop quantum cosmology (LQC) homogeneous models with a massless scalar field show that the big-bang singularity can be replaced by a big quantum bounce. To gain further insight on the nature of this bounce, we study the semidiscrete loop quantum gravity Hamiltonian constraint equation from the point of view of numerical analysis. For illustration purposes, we establish a numerical analogy between the quantum bounces and reflections in finite difference discretizations of wave equations triggered by the use of nonuniform grids or, equivalently, reflections found when solving numerically wave equations with varying coefficients. We show that the bounce is closely related to the method for the temporal update of the system and demonstrate that explicit time-updates in general yield bounces. Finally, we present an example of an implicit time-update devoid of bounces and show back-in-time, deterministic evolutions that reach and partially jump over the big-bang singularity

  13. Finite-State Mean-Field Games, Crowd Motion Problems, and its Numerical Methods

    KAUST Repository

    Machado Velho, Roberto

    2017-09-10

    In this dissertation, we present two research projects, namely finite-state mean-field games and the Hughes model for the motion of crowds. In the first part, we describe finite-state mean-field games and some applications to socio-economic sciences. Examples include paradigm shifts in the scientific community and the consumer choice behavior in a free market. The corresponding finite-state mean-field game models are hyperbolic systems of partial differential equations, for which we propose and validate a new numerical method. Next, we consider the dual formulation to two-state mean-field games, and we discuss numerical methods for these problems. We then depict different computational experiments, exhibiting a variety of behaviors, including shock formation, lack of invertibility, and monotonicity loss. We conclude the first part of this dissertation with an investigation of the shock structure for two-state problems. In the second part, we consider a model for the movement of crowds proposed by R. Hughes in [56] and describe a numerical approach to solve it. This model comprises a Fokker-Planck equation coupled with an Eikonal equation with Dirichlet or Neumann data. We first establish a priori estimates for the solutions. Next, we consider radial solutions, and we identify a shock formation mechanism. Subsequently, we illustrate the existence of congestion, the breakdown of the model, and the trend to the equilibrium. We also propose a new numerical method for the solution of Fokker-Planck equations and then to systems of PDEs composed by a Fokker-Planck equation and a potential type equation. Finally, we illustrate the use of the numerical method both to the Hughes model and mean-field games. We also depict cases such as the evacuation of a room and the movement of persons around Kaaba (Saudi Arabia).

  14. Techniques for capturing bighorn sheep lambs

    Science.gov (United States)

    Smith, Joshua B.; Walsh, Daniel P.; Goldstein, Elise J.; Parsons, Zachary D.; Karsch, Rebekah C.; Stiver, Julie R.; Cain, James W.; Raedeke, Kenneth J.; Jenks, Jonathan A.

    2014-01-01

    Low lamb recruitment is a major challenge facing managers attempting to mitigate the decline of bighorn sheep (Ovis canadensis), and investigations into the underlying mechanisms are limited because of the inability to readily capture and monitor bighorn sheep lambs. We evaluated 4 capture techniques for bighorn sheep lambs: 1) hand-capture of lambs from radiocollared adult females fitted with vaginal implant transmitters (VITs), 2) hand-capture of lambs of intensively monitored radiocollared adult females, 3) helicopter net-gunning, and 4) hand-capture of lambs from helicopters. During 2010–2012, we successfully captured 90% of lambs from females that retained VITs to ≤1 day of parturition, although we noted differences in capture rates between an area of high road density in the Black Hills (92–100%) of South Dakota, USA, and less accessible areas of New Mexico (71%), USA. Retention of VITs was 78% with pre-partum expulsion the main cause of failure. We were less likely to capture lambs from females that expelled VITs ≥1 day of parturition (range = 80–83%) or females that were collared without VITs (range = 60–78%). We used helicopter net-gunning at several sites in 1999, 2001–2002, and 2011, and it proved a useful technique; however, at one site, attempts to capture lambs led to lamb predation by golden eagles (Aquila chrysaetos). We attempted helicopter hand-captures at one site in 1999, and they also were successful in certain circumstances and avoided risk of physical trauma from net-gunning; however, application was limited. In areas of low accessibility or if personnel lack the ability to monitor females and/or VITs for extended periods, helicopter capture may provide a viable option for lamb capture.

  15. The National Carbon Capture Center at the Power Systems Development Facility

    Energy Technology Data Exchange (ETDEWEB)

    Mosser, Morgan [Southern Company Services, Inc., Wilsonville, AL (United States)

    2012-12-31

    The Power Systems Development Facility (PSDF) is a state-of-the-art test center sponsored by the U.S. Department of Energy and dedicated to the advancement of clean coal technology. In addition to the development of high efficiency coal gasification processes, the PSDF features the National Carbon Capture Center (NCCC) to promote new technologies for CO2 capture from coal-derived syngas and flue gas. The NCCC includes multiple, adaptable test skids that allow technology development of CO2 capture concepts using coal-derived syngas and flue gas in industrial settings. Because of the ability to operate under a wide range of flow rates and process conditions, research at the NCCC can effectively evaluate technologies at various levels of maturity and accelerate their development path to commercialization. During the calendar year 2012 portion of the Budget Period Four reporting period, efforts at the NCCC focused on testing of pre- and post-combustion CO2 capture processes and gasification support technologies. Preparations for future testing were on-going as well, and involved facility upgrades and collaboration with numerous technology developers. In the area of pre-combustion, testing was conducted on a new water-gas shift catalyst, a CO2 solvent, and gas separation membranes from four different technology developers, including two membrane systems incorporating major scale-ups. Post-combustion tests involved advanced solvents from three major developers, a gas separation membrane, and two different enzyme technologies. An advanced sensor for gasification operation was evaluated, operation with biomass co-feeding with coal under oxygen-blown conditions was achieved, and progress continued on refining several gasification support technologies.

  16. Numerical method for estimating the size of chaotic regions of phase space

    International Nuclear Information System (INIS)

    Henyey, F.S.; Pomphrey, N.

    1987-10-01

    A numerical method for estimating irregular volumes of phase space is derived. The estimate weights the irregular area on a surface of section with the average return time to the section. We illustrate the method by application to the stadium and oval billiard systems and also apply the method to the continuous Henon-Heiles system. 15 refs., 10 figs

  17. Attentional capture under high perceptual load.

    Science.gov (United States)

    Cosman, Joshua D; Vecera, Shaun P

    2010-12-01

    Attentional capture by abrupt onsets can be modulated by several factors, including the complexity, or perceptual load, of a scene. We have recently demonstrated that observers are less likely to be captured by abruptly appearing, task-irrelevant stimuli when they perform a search that is high, as opposed to low, in perceptual load (Cosman & Vecera, 2009), consistent with perceptual load theory. However, recent results indicate that onset frequency can influence stimulus-driven capture, with infrequent onsets capturing attention more often than did frequent onsets. Importantly, in our previous task, an abrupt onset was present on every trial, and consequently, attentional capture might have been affected by both onset frequency and perceptual load. In the present experiment, we examined whether onset frequency influences attentional capture under conditions of high perceptual load. When onsets were presented frequently, we replicated our earlier results; attentional capture by onsets was modulated under conditions of high perceptual load. Importantly, however, when onsets were presented infrequently, we observed robust capture effects. These results conflict with a strong form of load theory and, instead, suggest that exposure to the elements of a task (e.g., abrupt onsets) combines with high perceptual load to modulate attentional capture by task-irrelevant information.

  18. Short-term capture of the Earth-Moon system

    Science.gov (United States)

    Qi, Yi; de Ruiter, Anton

    2018-06-01

    In this paper, the short-term capture (STC) of an asteroid in the Earth-Moon system is proposed and investigated. First, the space condition of STC is analysed and five subsets of the feasible region are defined and discussed. Then, the time condition of STC is studied by parameter scanning in the Sun-Earth-Moon-asteroid restricted four-body problem. Numerical results indicate that there is a clear association between the distributions of the time probability of STC and the five subsets. Next, the influence of the Jacobi constant on STC is examined using the space and time probabilities of STC. Combining the space and time probabilities of STC, we propose a STC index to evaluate the probability of STC comprehensively. Finally, three potential STC asteroids are found and analysed.

  19. The calculation of resonance capture in granular fuels

    Energy Technology Data Exchange (ETDEWEB)

    Askew, J R; Harris, D W.G.; Hutton, J L

    1971-02-15

    The methods used in the UK for the calculation of resonance capture in granular HTR fuels follow the long established path of determining a 'geometric equivalence' which equates the resonance shielding to that in a homogeneous mixture of the resonance absorber in hydrogen. Simple collision probability arguments, usually for the black limit, were used for AGR and SGHW systems. For granular fuel a 'grey' equivalence, convenient for numerical use, has been adopted, and the geometric solution performed in two ways: by a synthetic collision probability model which is rapid and appropriate for design work and by a Monte Carlo model which allows details of the grain lattice structure to be studied. The results are in good agreement, and are shown to give good results compared with measured relative conversion ratios in the NESTOR stack experiments.

  20. The pressure equation arising in reservoir simulation. Mathematical properties, numerical methods and upscaling

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Bjoern Fredrik

    1997-12-31

    The main purpose of this thesis has been to analyse self-adjoint second order elliptic partial differential equations arising in reservoir simulation. It studies several mathematical and numerical problems for the pressure equation arising in models of fluid flow in porous media. The theoretical results obtained have been illustrated by a series of numerical experiments. The influence of large variations in the mobility tensor upon the solution of the pressure equation is analysed. The performance of numerical methods applied to such problems have been studied. A new upscaling technique for one-phase flow in heterogeneous reservoirs is developed. The stability of the solution of the pressure equation with respect to small perturbations of the mobility tensor is studied. The results are used to develop a new numerical method for a model of fully nonlinear water waves. 158 refs, 39 figs., 12 tabs.

  1. The pressure equation arising in reservoir simulation. Mathematical properties, numerical methods and upscaling

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Bjoern Fredrik

    1998-12-31

    The main purpose of this thesis has been to analyse self-adjoint second order elliptic partial differential equations arising in reservoir simulation. It studies several mathematical and numerical problems for the pressure equation arising in models of fluid flow in porous media. The theoretical results obtained have been illustrated by a series of numerical experiments. The influence of large variations in the mobility tensor upon the solution of the pressure equation is analysed. The performance of numerical methods applied to such problems have been studied. A new upscaling technique for one-phase flow in heterogeneous reservoirs is developed. The stability of the solution of the pressure equation with respect to small perturbations of the mobility tensor is studied. The results are used to develop a new numerical method for a model of fully nonlinear water waves. 158 refs, 39 figs., 12 tabs.

  2. Extended Field Laser Confocal Microscopy (EFLCM): Combining automated Gigapixel image capture with in silico virtual microscopy

    International Nuclear Information System (INIS)

    Flaberg, Emilie; Sabelström, Per; Strandh, Christer; Szekely, Laszlo

    2008-01-01

    Confocal laser scanning microscopy has revolutionized cell biology. However, the technique has major limitations in speed and sensitivity due to the fact that a single laser beam scans the sample, allowing only a few microseconds signal collection for each pixel. This limitation has been overcome by the introduction of parallel beam illumination techniques in combination with cold CCD camera based image capture. Using the combination of microlens enhanced Nipkow spinning disc confocal illumination together with fully automated image capture and large scale in silico image processing we have developed a system allowing the acquisition, presentation and analysis of maximum resolution confocal panorama images of several Gigapixel size. We call the method Extended Field Laser Confocal Microscopy (EFLCM). We show using the EFLCM technique that it is possible to create a continuous confocal multi-colour mosaic from thousands of individually captured images. EFLCM can digitize and analyze histological slides, sections of entire rodent organ and full size embryos. It can also record hundreds of thousands cultured cells at multiple wavelength in single event or time-lapse fashion on fixed slides, in live cell imaging chambers or microtiter plates. The observer independent image capture of EFLCM allows quantitative measurements of fluorescence intensities and morphological parameters on a large number of cells. EFLCM therefore bridges the gap between the mainly illustrative fluorescence microscopy and purely quantitative flow cytometry. EFLCM can also be used as high content analysis (HCA) instrument for automated screening processes

  3. Exploratory investigations of hypervelocity intact capture spectroscopy

    Science.gov (United States)

    Tsou, P.; Griffiths, D. J.

    1993-01-01

    The ability to capture hypervelocity projectiles intact opens a new technique available for hypervelocity research. A determination of the reactions taking place between the projectile and the capture medium during the process of intact capture is extremely important to an understanding of the intact capture phenomenon, to improving the capture technique, and to developing a theory describing the phenomenon. The intact capture of hypervelocity projectiles by underdense media generates spectra, characteristic of the material species of projectile and capture medium involved. Initial exploratory results into real-time characterization of hypervelocity intact capture techniques by spectroscopy include ultra-violet and visible spectra obtained by use of reflecting gratings, transmitting gratings, and prisms, and recorded by photographic and electronic means. Spectrometry proved to be a valuable real-time diagnostic tool for hypervelocity intact capture events, offering understanding of the interactions of the projectile and the capture medium during the initial period and providing information not obtainable by other characterizations. Preliminary results and analyses of spectra produced by the intact capture of hypervelocity aluminum spheres in polyethylene (PE), polystyrene (PS), and polyurethane (PU) foams are presented. Included are tentative emission species identifications, as well as gray body temperatures produced in the intact capture process.

  4. What Determines State Capture in Poland?

    Directory of Open Access Journals (Sweden)

    Stanisław Alwasiak

    2013-12-01

    Full Text Available Purpose: This study examines the determinants of ex-ante state capture in Poland. Methodology: In order to establish the determinants of ex-ante state capture a logistic regression is estimated. Findings: The study shows that in Poland the majority of legal acts were passed with the aim to satisfy the interest of particular groups. Furthermore, the regression analysis shows that the likelihood of state capture increases during the period of higher economic growth and local elections. The likelihood of state capture, however, declines during presidential elections. The results we attribute to different interests of political parties in the period of local and presidential elections. Finally, we fi nd that the state capture increased over the years in Poland. Additionally, we show that the EU accession did not prevent state capture in Poland. In contrast, the fi nancial crisis of 2007 resulted in a wake-up effect and the likelihood of state capture declined in Poland. Research limitations: In the study we employ proxies for state capture, yet we assume that corruption is a widespread phenomenon in Poland. However, due to its nature corruption is very diffi cult to assess and measure. Originality: The study uses a unique dataset on ex-ante state capture that was identifi ed in the legal acts that have been passed in the period 1990–2011 in Poland.

  5. Volume illustration of muscle from diffusion tensor images.

    Science.gov (United States)

    Chen, Wei; Yan, Zhicheng; Zhang, Song; Crow, John Allen; Ebert, David S; McLaughlin, Ronald M; Mullins, Katie B; Cooper, Robert; Ding, Zi'ang; Liao, Jun

    2009-01-01

    Medical illustration has demonstrated its effectiveness to depict salient anatomical features while hiding the irrelevant details. Current solutions are ineffective for visualizing fibrous structures such as muscle, because typical datasets (CT or MRI) do not contain directional details. In this paper, we introduce a new muscle illustration approach that leverages diffusion tensor imaging (DTI) data and example-based texture synthesis techniques. Beginning with a volumetric diffusion tensor image, we reformulate it into a scalar field and an auxiliary guidance vector field to represent the structure and orientation of a muscle bundle. A muscle mask derived from the input diffusion tensor image is used to classify the muscle structure. The guidance vector field is further refined to remove noise and clarify structure. To simulate the internal appearance of the muscle, we propose a new two-dimensional example based solid texture synthesis algorithm that builds a solid texture constrained by the guidance vector field. Illustrating the constructed scalar field and solid texture efficiently highlights the global appearance of the muscle as well as the local shape and structure of the muscle fibers in an illustrative fashion. We have applied the proposed approach to five example datasets (four pig hearts and a pig leg), demonstrating plausible illustration and expressiveness.

  6. Development of early numerical abilities of Spanish-speaking Mexican preschoolers: A new assessment tool.

    Science.gov (United States)

    Beltrán-Navarro, Beatriz; Abreu-Mendoza, Roberto A; Matute, Esmeralda; Rosselli, Monica

    2018-01-01

    This article presents a tool for assessing the early numerical abilities of Spanish-speaking Mexican preschoolers. The Numerical Abilities Test, from the Evaluación Neuropsicológica Infantil-Preescolar (ENI-P), evaluates four core abilities of number development: magnitude comparison, counting, subitizing, and basic calculation. We evaluated 307 Spanish-speaking Mexican children aged 2 years 6 months to 4 years 11 months. Appropriate internal consistency and test-retest reliability were demonstrated. We also investigated the effect of age, children's school attendance, maternal education, and sex on children's numerical scores. The results showed that the four subtests captured development across ages. Critically, maternal education had an impact on children's performance in three out of the four subtests, but there was no effect associated with children's school attendance or sex. These results suggest that the Numerical Abilities Test is a reliable instrument for Spanish-speaking preschoolers. We discuss the implications of our outcomes for numerical development.

  7. Etude des erreurs d'estimation des populations par la méthode des captures successives (DeLURY, 2 captures et des captures-recaptures (PETERSEN

    Directory of Open Access Journals (Sweden)

    LAURENT M.

    1978-01-01

    Full Text Available L'estimation des populations naturelles par capture-recapture et par captures successives est souvent entachée d'erreur car, dans de nombreux cas, l'hypothèse fondamentale d'égalité des probabilités de captures pour tous les individus dans le temps et dans l'espace n'est pas respectée. Dans le cas des populations de poissons envisagés ici, les captures ont lieu par la pêche électrique. On a pu chiffrer l'ordre de grandeur des erreurs systématiques faites sur l'estimation des peuplements, en fonction des conditions particulières, biotiques et abiotiques, des différents milieux inventoriés.

  8. 3D numerical simulation of transient processes in hydraulic turbines

    International Nuclear Information System (INIS)

    Cherny, S; Chirkov, D; Lapin, V; Eshkunova, I; Bannikov, D; Avdushenko, A; Skorospelov, V

    2010-01-01

    An approach for numerical simulation of 3D hydraulic turbine flows in transient operating regimes is presented. The method is based on a coupled solution of incompressible RANS equations, runner rotation equation, and water hammer equations. The issue of setting appropriate boundary conditions is considered in detail. As an illustration, the simulation results for runaway process are presented. The evolution of vortex structure and its effect on computed runaway traces are analyzed.

  9. 3D numerical simulation of transient processes in hydraulic turbines

    Science.gov (United States)

    Cherny, S.; Chirkov, D.; Bannikov, D.; Lapin, V.; Skorospelov, V.; Eshkunova, I.; Avdushenko, A.

    2010-08-01

    An approach for numerical simulation of 3D hydraulic turbine flows in transient operating regimes is presented. The method is based on a coupled solution of incompressible RANS equations, runner rotation equation, and water hammer equations. The issue of setting appropriate boundary conditions is considered in detail. As an illustration, the simulation results for runaway process are presented. The evolution of vortex structure and its effect on computed runaway traces are analyzed.

  10. Congenital diseases and syndromes. An illustrated radiological guide

    Energy Technology Data Exchange (ETDEWEB)

    Al-Tubaikh, Jarrah Ali [Universitaetsklinikum Muenchen, Klinikum Grosshadern (Germany). Inst. fuer Klinische Radiologie; Sabah Hospital (Kuwait). Dept. of Diagnostic Radiology; Reiser, Maximilian F. [Universitaetsklinikum Muenchen, Klinikum Grosshadern (Germany). Inst. fuer Klinische Radiologie

    2009-07-01

    Congenital Diseases and Syndromes - An Illustrated Radiological Guide is designed to serve the radiologist as an easy-to-use visual guide that illustrates the typical diagnostic radiological features of the most common congenital diseases and syndromes. The book is organised according to body system, with chapters focusing on the CNS, the head and neck, the chest and heart, the abdomen and pelvis, and the musculoskeletal system. A final chapter is devoted to phakomatosis. Each syndrome or disease is illustrated by multiple images as well as by high-quality digital medical illustrations depicting those radiological signs that are difficult to detect. The reader is thereby familiarised with the various congenital anomalies from the radiological point of view. In addition, etiology, diagnostic criteria, and main symptoms are described, and potential differential diagnoses highlighted. This book will be immensely useful for junior radiologists, radiology students, and doctors in any specialty who are interested in congenital malformations and syndromes. (orig.)

  11. Congenital diseases and syndromes. An illustrated radiological guide

    International Nuclear Information System (INIS)

    Al-Tubaikh, Jarrah Ali; Sabah Hospital; Reiser, Maximilian F.

    2009-01-01

    Congenital Diseases and Syndromes - An Illustrated Radiological Guide is designed to serve the radiologist as an easy-to-use visual guide that illustrates the typical diagnostic radiological features of the most common congenital diseases and syndromes. The book is organised according to body system, with chapters focusing on the CNS, the head and neck, the chest and heart, the abdomen and pelvis, and the musculoskeletal system. A final chapter is devoted to phakomatosis. Each syndrome or disease is illustrated by multiple images as well as by high-quality digital medical illustrations depicting those radiological signs that are difficult to detect. The reader is thereby familiarised with the various congenital anomalies from the radiological point of view. In addition, etiology, diagnostic criteria, and main symptoms are described, and potential differential diagnoses highlighted. This book will be immensely useful for junior radiologists, radiology students, and doctors in any specialty who are interested in congenital malformations and syndromes. (orig.)

  12. Adiabatic capture and debunching

    International Nuclear Information System (INIS)

    Ng, K.Y.

    2012-01-01

    In the study of beam preparation for the g-2 experiment, adiabatic debunching and adiabatic capture are revisited. The voltage programs for these adiabbatic processes are derived and their properties discussed. Comparison is made with some other form of adiabatic capture program. The muon g-2 experiment at Fermilab calls for intense proton bunches for the creation of muons. A booster batch of 84 bunches is injected into the Recycler Ring, where it is debunched and captured into 4 intense bunches with the 2.5-MHz rf. The experiment requires short bunches with total width less than 100 ns. The transport line from the Recycler to the muon-production target has a low momentum aperture of ∼ ±22 MeV. Thus each of the 4 intense proton bunches required to have an emittance less than ∼ 3.46 eVs. The incoming booster bunches have total emittance ∼ 8.4 eVs, or each one with an emittance ∼ 0.1 eVs. However, there is always emittance increase when the 84 booster bunches are debunched. There will be even larger emittance increase during adiabatic capture into the buckets of the 2.5-MHz rf. In addition, the incoming booster bunches may have emittances larger than 0.1 eVs. In this article, we will concentrate on the analysis of the adiabatic capture process with the intention of preserving the beam emittance as much as possible. At this moment, beam preparation experiment is being performed at the Main Injector. Since the Main Injector and the Recycler Ring have roughly the same lattice properties, we are referring to adiabatic capture in the Main Injector instead in our discussions.

  13. The codification of directors’ duties: Capturing the essence of the corporate opportunity doctrine

    Directory of Open Access Journals (Sweden)

    John Lowry

    2006-07-01

    Full Text Available It is suggested in the paper that section 176 is too compendious in its drafting. A consequence of this is that the declared objectives of the CLR to make the law comprehensible and, therefore, accessible is undermined. It fails to capture the essence of the principles that have emerged from the case law on the no-conflicts rule and the corporate opportunity. Further, the differing approaches towards the determination of liability by the Court of Appeal in Bhullar, on the one hand, and the more open textured approach towards the issue in Pyke, illustrates the dichotomy of the case law surrounding the corporate opportunity doctrine which the language of section 176 fails to resolve.

  14. Component-oriented approach to the development and use of numerical models in high energy physics

    International Nuclear Information System (INIS)

    Amelin, N.S.; Komogorov, M.Eh.

    2002-01-01

    We discuss the main concepts of a component approach to the development and use of numerical models in high energy physics. This approach is realized as the NiMax software system. The discussed concepts are illustrated by numerous examples of the system user session. In appendix chapter we describe physics and numerical algorithms of the model components to perform simulation of hadronic and nuclear collisions at high energies. These components are members of hadronic application modules that have been developed with the help of the NiMax system. Given report is served as an early release of the NiMax manual mainly for model component users

  15. Numerical Analysis on Combustion Characteristic of Leaf Spring Rotary Engine

    Directory of Open Access Journals (Sweden)

    Yan Zhang

    2015-08-01

    Full Text Available The purpose of this paper is to investigate combustion characteristics for rotary engine via numerical studies. A 3D numerical model was developed to study the influence of several operative parameters on combustion characteristics. A novel rotary engine called, “Leaf Spring Rotary Engine”, was used to illustrate the structure and principle of the engine. The aims are to (1 improve the understanding of combustion process, and (2 quantify the influence of rotational speed, excess air ratio, initial pressure and temperature on combustion characteristics. The chamber space changed with crankshaft rotation. Due to the complexity of chamber volume, an equivalent modeling method was presented to simulate the chamber space variation. The numerical simulations were performed by solving the incompressible, multiphase Unsteady Reynolds-Averaged Navier–Stokes Equations via the commercial code FLUENT using a transport equation-based combustion model; a realizable  turbulence model and finite-rate/eddy-dissipation model were used to account for the effect of local factors on the combustion characteristics.

  16. 26 CFR 1.941-3 - Illustration of principles.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 10 2010-04-01 2010-04-01 false Illustration of principles. 1.941-3 Section 1.941-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES China Trade Act Corporations § 1.941-3 Illustration of principles. The application...

  17. The Generic Data Capture Facility

    Science.gov (United States)

    Connell, Edward B.; Barnes, William P.; Stallings, William H.

    1987-01-01

    The Generic Data Capture Facility, which can provide data capture support for a variety of different types of spacecraft while enabling operations costs to be carefully controlled, is discussed. The data capture functions, data protection, isolation of users from data acquisition problems, data reconstruction, and quality and accounting are addressed. The TDM and packet data formats utilized by the system are described, and the development of generic facilities is considered.

  18. Negative meson capture in hydrogen

    International Nuclear Information System (INIS)

    Baird, T.J.

    1977-01-01

    The processes of deexcitation and capture of negative mesons and hadrons in atomic hydrogen are investigated. Only slow collisions in which the projectile-atom relative velocity is less than one atomic unit are considered, and the motion of the incident particle is treated classically. For each classical trajectory the probability of ionizing the hydrogen atom is determined, together with the energy spectrum of the emitted electron. Ionization probabilities are calculated using the time-dependent formulation of the perturbed stationary state method. Exact two-center electronic wave functions are used for both bound and continuum states. The total ionization cross section and electron energy spectrum have been calculated for negative muons, kaons and antiprotons at incident relative velocities between 0.04 and 1.0 atomic units. The electron energy spectrum has a sharp peak for electron kinetic energies on the order of 10 -3 Rydbergs. The ionization process thus favors the emission of very slow electrons. The cross section for ionization with capture of the incident particle was calculated for relative kinetic energies greater than 1.0 Rydberg. Since ionization was found to occur with the emission of electrons of nearly zero kinetic energy, the fraction of ionizing collisions which result in capture decreases very rapidly with projectile kinetic energy. The energy distributions of slowed down muons and hadrons were also computed. These distributions were used together with the capture cross section to determine the distribution of kinetic energies at which capture takes place. It was found that most captures occur for kinetic energies slightly less than 1.0 Rydbergs with relatively little capture at thermal energies. The captured particles therefore tend to go into very large and loosely found orbits with binding energies less than 0.1 Rydbergs

  19. CO2 CAPTURE PROJECT - AN INTEGRATED, COLLABORATIVE TECHNOLOGY DEVELOPMENT PROJECT FOR NEXT GENERATION CO2 SEPARATION, CAPTURE AND GEOLOGIC SEQUESTRATION

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Helen Kerr

    2003-08-01

    The CO{sub 2} Capture Project (CCP) is a joint industry project, funded by eight energy companies (BP, ChevronTexaco, EnCana, Eni, Norsk Hydro, Shell, Statoil, and Suncor) and three government agencies (1) European Union (DG Res & DG Tren), (2) Norway (Klimatek) and (3) the U.S.A. (Department of Energy). The project objective is to develop new technologies, which could reduce the cost of CO{sub 2} capture and geologic storage by 50% for retrofit to existing plants and 75% for new-build plants. Technologies are to be developed to ''proof of concept'' stage by the end of 2003. The project budget is approximately $24 million over 3 years and the work program is divided into eight major activity areas: (1) Baseline Design and Cost Estimation--defined the uncontrolled emissions from each facility and estimate the cost of abatement in $/tonne CO{sub 2}. (2) Capture Technology, Post Combustion: technologies, which can remove CO{sub 2} from exhaust gases after combustion. (3) Capture Technology, Oxyfuel: where oxygen is separated from the air and then burned with hydrocarbons to produce an exhaust with high CO{sub 2} for storage. (4) Capture Technology, Pre -Combustion: in which, natural gas and petroleum coke are converted to hydrogen and CO{sub 2} in a reformer/gasifier. (5) Common Economic Model/Technology Screening: analysis and evaluation of each technology applied to the scenarios to provide meaningful and consistent comparison. (6) New Technology Cost Estimation: on a consistent basis with the baseline above, to demonstrate cost reductions. (7) Geologic Storage, Monitoring and Verification (SMV): providing assurance that CO{sub 2} can be safely stored in geologic formations over the long term. (8) Non-Technical: project management, communication of results and a review of current policies and incentives governing CO{sub 2} capture and storage. Technology development work dominated the past six months of the project. Numerous studies are making

  20. CAPTURED India Country Evaluation

    NARCIS (Netherlands)

    O'Donoghue, R.; Brouwers, J.H.A.M.

    2012-01-01

    This report provides the findings of the India Country Evaluation and is produced as part of the overall CAPTURED End Evaluation. After five years of support by the CAPTURED project the End Evaluation has assessed that results are commendable. I-AIM was able to design an approach in which health

  1. Carbon Capture and Storage

    NARCIS (Netherlands)

    Benson, S.M.; Bennaceur, K.; Cook, P.; Davison, J.; Coninck, H. de; Farhat, K.; Ramirez, C.A.; Simbeck, D.; Surles, T.; Verma, P.; Wright, I.

    2012-01-01

    Emissions of carbon dioxide, the most important long-lived anthropogenic greenhouse gas, can be reduced by Carbon Capture and Storage (CCS). CCS involves the integration of four elements: CO 2 capture, compression of the CO2 from a gas to a liquid or a denser gas, transportation of pressurized CO 2

  2. Effect of charged line defects on conductivity in graphene: Numerical Kubo and analytical Boltzmann approaches

    DEFF Research Database (Denmark)

    Radchenko, T. M.; Shylau, A. A.; Zozoulenko, I. V.

    2013-01-01

    . A numerical study of electronic transport is performed by means of a time-dependent real-space Kubo approach in honeycomb lattices containing millions of carbon atoms, capturing the linear response of realistic size systems in the highly disordered regime. Our numerical calculations are complemented...... with the Kubo calculations. In the strong scattering regime, the conductivity is found to be a sublinear function of electronic density and weakly dependent on the Thomas-Fermi screening wavelength. We attribute this atypical behavior to the extended nature of one-dimensional charged defects. Our results...

  3. Giant resonance effects in radiative capture

    International Nuclear Information System (INIS)

    Snover, K.A.

    1979-01-01

    The technique of capture reaction studies of giant resonance properties is described, and a number of examples are given. Most of the recent work of interest has been in proton capture, in part because of the great utility (and availability) of polarized beams; most of the discussion concerns this reaction. Alpha capture, which has been a useful tool for exploring isoscalar E2 strength, and neutron capture are, however, also treated. 46 references, 14 figures

  4. Motion Capturing Emotions

    OpenAIRE

    Wood Karen; Cisneros Rosemary E.; Whatley Sarah

    2017-01-01

    The paper explores the activities conducted as part of WhoLoDancE: Whole Body Interaction Learning for Dance Education which is an EU-funded Horizon 2020 project. In particular, we discuss the motion capture sessions that took place at Motek, Amsterdam as well as the dancers’ experience of being captured and watching themselves or others as varying visual representations through the HoloLens. HoloLens is Microsoft’s first holographic computer that you wear as you would a pair of glasses. The ...

  5. Direct numerical simulations of turbulent lean premixed combustion

    International Nuclear Information System (INIS)

    Sankaran, Ramanan; Hawkes, Evatt R; Chen, Jacqueline H; Lu Tianfeng; Law, Chung K

    2006-01-01

    In recent years, due to the advent of high-performance computers and advanced numerical algorithms, direct numerical simulation (DNS) of combustion has emerged as a valuable computational research tool, in concert with experimentation. The role of DNS in delivering new Scientific insight into turbulent combustion is illustrated using results from a recent 3D turbulent premixed flame simulation. To understand the influence of turbulence on the flame structure, a 3D fully-resolved DNS of a spatially-developing lean methane-air turbulent Bunsen flame was performed in the thin reaction zones regime. A reduced chemical model for methane-air chemistry consisting of 13 resolved species, 4 quasi-steady state species and 73 elementary reactions was developed specifically for the current simulation. The data is analyzed to study possible influences of turbulence on the flame thickness. The results show that the average flame thickness increases, in qualitative agreement with several experimental results

  6. Numerical perturbative methods in the quantum theory of physical systems

    International Nuclear Information System (INIS)

    Adam, G.

    1980-01-01

    During the last two decades, development of digital electronic computers has led to the deployment of new, distinct methods in theoretical physics. These methods, based on the advances of modern numerical analysis as well as on specific equations describing physical processes, enabled to perform precise calculations of high complexity which have completed and sometimes changed our image of many physical phenomena. Our efforts have concentrated on the development of numerical methods with such intrinsic performances as to allow a successful approach of some Key issues in present theoretical physics on smaller computation systems. The basic principle of such methods is to translate, in numerical analysis language, the theory of perturbations which is suited to numerical rather than to analytical computation. This idea has been illustrated by working out two problems which arise from the time independent Schroedinger equation in the non-relativistic approximation, within both quantum systems with a small number of particles and systems with a large number of particles, respectively. In the first case, we are led to the numerical solution of some quadratic ordinary differential equations (first section of the thesis) and in the second case, to the solution of some secular equations in the Brillouin area (second section). (author)

  7. Eikonal calculation of electron-capture cross sections in collisions of H atoms with fast projectiles

    International Nuclear Information System (INIS)

    Ho, T.S.; Lieber, M.; Chan, F.T.

    1981-01-01

    We have employed the eikonal method to calculate the cross section for the capture of an electron into an arbitrary nl subshell in collisions between hydrogen atoms and fast projectiles. the projectiles were protons, C 6+ , O 8+ , and Fe 24+ . The energy ranges considered were 20--100 keV in the proton case, and 40--200 keV per nucleon in the other cases. These projectiles were selected because of their importance in fusion plasmas. For the highly charged case of Fe 24+ we found that our formulas, while exact, involved a high degree of cancellation and produced unreliable numerical results, so that a numerical integration of the penultimate formula was substituted. In the proton case agreement with recent experimental data is excellent

  8. A survey of the Carbon Capture

    International Nuclear Information System (INIS)

    Jokrllova, J.; Cik, G.; Takacova, A.; Smolinska, M.

    2014-01-01

    The concentration of carbon dioxide, one of the most important representatives of greenhouse gases in the atmosphere continues to rise. Fossil fuels burned in thermal power plants currently represent 80% of total energy production around the world and are the largest point sources of CO 2 , accounting for approximately 40% of total CO 2 emissions. There are several options for reducing CO 2 emissions: reducing demand, improving production efficiency and carbon capture and storage (CCS, carbon capture and storage). Capture and storage of carbon dioxide is generally a three-step process: 1 st Capture and compression of combustion products, 2 nd transport (mostly pipeline) and 3 rd utilization (eg. production of urea, beverage industry, production of dry ice, etc.). Technologies for CO 2 capturing used in power plants burning fossil fuels can be divided into four groups, each of which requires a completely different approach to CO 2 capture.

  9. Formation of Tidal Captures and Gravitational Wave Inspirals in Binary-single Interactions

    International Nuclear Information System (INIS)

    Samsing, Johan; MacLeod, Morgan; Ramirez-Ruiz, Enrico

    2017-01-01

    We perform the first systematic study of how dynamical stellar tides and general relativistic (GR) effects affect the dynamics and outcomes of binary-single interactions. For this, we have constructed an N -body code that includes tides in the affine approximation, where stars are modeled as self-similar ellipsoidal polytropes, and GR corrections using the commonly used post-Newtonian formalism. Using this numerical formalism, we are able resolve the leading effect from tides and GR across several orders of magnitude in both stellar radius and initial target binary separation. We find that the main effect from tides is the formation of two-body tidal captures that form during the chaotic and resonant evolution of the triple system. The two stars undergoing the capture spiral in and merge. The inclusion of tides can thus lead to an increase in the stellar coalescence rate. We also develop an analytical framework for calculating the cross section of tidal inspirals between any pair of objects with similar mass. From our analytical and numerical estimates, we find that the rate of tidal inspirals relative to collisions increases as the initial semimajor axis of the target binary increases and the radius of the interacting tidal objects decreases. The largest effect is therefore found for triple systems hosting white dwarfs and neutron stars (NSs). In this case, we find the rate of highly eccentric white dwarf—NS mergers to likely be dominated by tidal inspirals. While tidal inspirals occur rarely, we note that they can give rise to a plethora of thermonuclear transients, such as Ca-rich transients.

  10. Formation of Tidal Captures and Gravitational Wave Inspirals in Binary-single Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Samsing, Johan [Department of Astrophysical Sciences, Princeton University, Peyton Hall, 4 Ivy Lane, Princeton, NJ 08544 (United States); MacLeod, Morgan [School of Natural Sciences, Institute for Advanced Study, 1 Einstein Drive, Princeton, NJ 08540 (United States); Ramirez-Ruiz, Enrico [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)

    2017-09-01

    We perform the first systematic study of how dynamical stellar tides and general relativistic (GR) effects affect the dynamics and outcomes of binary-single interactions. For this, we have constructed an N -body code that includes tides in the affine approximation, where stars are modeled as self-similar ellipsoidal polytropes, and GR corrections using the commonly used post-Newtonian formalism. Using this numerical formalism, we are able resolve the leading effect from tides and GR across several orders of magnitude in both stellar radius and initial target binary separation. We find that the main effect from tides is the formation of two-body tidal captures that form during the chaotic and resonant evolution of the triple system. The two stars undergoing the capture spiral in and merge. The inclusion of tides can thus lead to an increase in the stellar coalescence rate. We also develop an analytical framework for calculating the cross section of tidal inspirals between any pair of objects with similar mass. From our analytical and numerical estimates, we find that the rate of tidal inspirals relative to collisions increases as the initial semimajor axis of the target binary increases and the radius of the interacting tidal objects decreases. The largest effect is therefore found for triple systems hosting white dwarfs and neutron stars (NSs). In this case, we find the rate of highly eccentric white dwarf—NS mergers to likely be dominated by tidal inspirals. While tidal inspirals occur rarely, we note that they can give rise to a plethora of thermonuclear transients, such as Ca-rich transients.

  11. A Discrete Numerical Scheme of Modified Leslie-Gower With Harvesting Model

    Directory of Open Access Journals (Sweden)

    Riski Nur Istiqomah Dinnullah

    2018-05-01

    Full Text Available Recently, exploitation of biological resources and the harvesting of two populations or more are widely practiced, such as fishery or foresty. The simplest way to describe the interaction of two species is by using predator prey model, that is one species feeds on another. The Leslie-Gower predator prey model has been studied in many works. In this paper, we use Euler method to discretisize the modified Leslie-Gower with harvesting model. The model consists of two simultanious predator prey equations. We show numerically that this discrete numerical scheme model is dynamically consistent with its continuous model only for relatively small step-size. By using computer simulation software, we show that equlibrium points can be stable, saddles, and unstable. It is shown that the numerical simulations not only illustrate the results, but also show the rich dynamics behaviors of the discrete system.

  12. SMD-based numerical stochastic perturbation theory

    Science.gov (United States)

    Dalla Brida, Mattia; Lüscher, Martin

    2017-05-01

    The viability of a variant of numerical stochastic perturbation theory, where the Langevin equation is replaced by the SMD algorithm, is examined. In particular, the convergence of the process to a unique stationary state is rigorously established and the use of higher-order symplectic integration schemes is shown to be highly profitable in this context. For illustration, the gradient-flow coupling in finite volume with Schrödinger functional boundary conditions is computed to two-loop (i.e. NNL) order in the SU(3) gauge theory. The scaling behaviour of the algorithm turns out to be rather favourable in this case, which allows the computations to be driven close to the continuum limit.

  13. SMD-based numerical stochastic perturbation theory

    Energy Technology Data Exchange (ETDEWEB)

    Dalla Brida, Mattia [Universita di Milano-Bicocca, Dipartimento di Fisica, Milan (Italy); INFN, Sezione di Milano-Bicocca (Italy); Luescher, Martin [CERN, Theoretical Physics Department, Geneva (Switzerland); AEC, Institute for Theoretical Physics, University of Bern (Switzerland)

    2017-05-15

    The viability of a variant of numerical stochastic perturbation theory, where the Langevin equation is replaced by the SMD algorithm, is examined. In particular, the convergence of the process to a unique stationary state is rigorously established and the use of higher-order symplectic integration schemes is shown to be highly profitable in this context. For illustration, the gradient-flow coupling in finite volume with Schroedinger functional boundary conditions is computed to two-loop (i.e. NNL) order in the SU(3) gauge theory. The scaling behaviour of the algorithm turns out to be rather favourable in this case, which allows the computations to be driven close to the continuum limit. (orig.)

  14. SMD-based numerical stochastic perturbation theory

    International Nuclear Information System (INIS)

    Dalla Brida, Mattia; Luescher, Martin

    2017-01-01

    The viability of a variant of numerical stochastic perturbation theory, where the Langevin equation is replaced by the SMD algorithm, is examined. In particular, the convergence of the process to a unique stationary state is rigorously established and the use of higher-order symplectic integration schemes is shown to be highly profitable in this context. For illustration, the gradient-flow coupling in finite volume with Schroedinger functional boundary conditions is computed to two-loop (i.e. NNL) order in the SU(3) gauge theory. The scaling behaviour of the algorithm turns out to be rather favourable in this case, which allows the computations to be driven close to the continuum limit. (orig.)

  15. US Spacesuit Knowledge Capture

    Science.gov (United States)

    Chullen, Cinda; Thomas, Ken; McMann, Joe; Dolan, Kristi; Bitterly, Rose; Lewis, Cathleen

    2011-01-01

    The ability to learn from both the mistakes and successes of the past is vital to assuring success in the future. Due to the close physical interaction between spacesuit systems and human beings as users, spacesuit technology and usage lends itself rather uniquely to the benefits realized from the skillful organization of historical information; its dissemination; the collection and identification of artifacts; and the education of those in the field. The National Aeronautics and Space Administration (NASA), other organizations and individuals have been performing United States (U.S.) Spacesuit Knowledge Capture since the beginning of space exploration. Avenues used to capture the knowledge have included publication of reports; conference presentations; specialized seminars; and classes usually given by veterans in the field. More recently the effort has been more concentrated and formalized whereby a new avenue of spacesuit knowledge capture has been added to the archives in which videotaping occurs engaging both current and retired specialists in the field presenting technical scope specifically for education and preservation of knowledge. With video archiving, all these avenues of learning can now be brought to life with the real experts presenting their wealth of knowledge on screen for future learners to enjoy. Scope and topics of U.S. spacesuit knowledge capture have included lessons learned in spacesuit technology, experience from the Gemini, Apollo, Skylab and Shuttle programs, hardware certification, design, development and other program components, spacesuit evolution and experience, failure analysis and resolution, and aspects of program management. Concurrently, U.S. spacesuit knowledge capture activities have progressed to a level where NASA, the National Air and Space Museum (NASM), Hamilton Sundstrand (HS) and the spacesuit community are now working together to provide a comprehensive closed-looped spacesuit knowledge capture system which includes

  16. Continuum capture in the three-body problem

    International Nuclear Information System (INIS)

    Sellin, I.A.

    1980-01-01

    The three-body problem, especially the problem of electron capture to the continuum in heavy particle collisions is reviewed. Major topics covered include: second born-induced asymmetry in electron capture to the continuum; historical context, links to other tests of atomic scattering theory; experiments characterizing the velocity distribution of ECC electrons; other atomic physics tests of high velocity Born expansions; atom capture; capture by positrons; and pion capture to the continuum

  17. The Effect of Illustration on Improving Text Comprehension in Dyslexic Adults

    Science.gov (United States)

    Wennås Brante, Eva; Nyström, Marcus

    2016-01-01

    This study analyses the effect of pictures in reading materials on the viewing patterns of dyslexic adults. By analysing viewing patterns using eye‐tracking, we captured differences in eye movements between young adults with dyslexia and controls based on the influence of reading skill as a continuous variable of the total sample. Both types of participants were assigned randomly to view either text‐only or a text + picture stimuli. The results show that the controls made an early global overview of the material and (when a picture was present) rapid transitions between text and picture. Having text illustrated with a picture decreased scores on questions about the learning material among participants with dyslexia. Controls spent 1.7% and dyslexic participants 1% of their time on the picture. Controls had 24% fewer total fixations; however, 29% more of the control group's fixations than the dyslexic group's fixations were on the picture. We also looked for effects of different types of pictures. Dyslexic subjects exhibited a comparable viewing pattern to controls when scenes were complex, but fewer fixations when scenes were neutral/simple. Individual scan paths are presented as examples of atypical viewing patterns for individuals with dyslexia as compared with controls. © 2016 The Authors. Dyslexia published by John Wiley & Sons Ltd. PMID:27892641

  18. Verification of a novel innovative blade root design for wind turbines using a hybrid numerical method

    DEFF Research Database (Denmark)

    Zhu, Wei Jun; Shen, Wen Zhong; Sørensen, Jens Nørkær

    2017-01-01

    captured at the outer part of the blades, where the relative wind speed is high. To assess the impact of this novel design idea, a hybrid numerical technique, based on solving the Reynolds-averaged Navier-Stokes equations, is utilized to determine the aerodynamic performance. The in-house developed Ellip...

  19. Numerical solution of special ultra-relativistic Euler equations using central upwind scheme

    Science.gov (United States)

    Ghaffar, Tayabia; Yousaf, Muhammad; Qamar, Shamsul

    2018-06-01

    This article is concerned with the numerical approximation of one and two-dimensional special ultra-relativistic Euler equations. The governing equations are coupled first-order nonlinear hyperbolic partial differential equations. These equations describe perfect fluid flow in terms of the particle density, the four-velocity and the pressure. A high-resolution shock-capturing central upwind scheme is employed to solve the model equations. To avoid excessive numerical diffusion, the considered scheme avails the specific information of local propagation speeds. By using Runge-Kutta time stepping method and MUSCL-type initial reconstruction, we have obtained 2nd order accuracy of the proposed scheme. After discussing the model equations and the numerical technique, several 1D and 2D test problems are investigated. For all the numerical test cases, our proposed scheme demonstrates very good agreement with the results obtained by well-established algorithms, even in the case of highly relativistic 2D test problems. For validation and comparison, the staggered central scheme and the kinetic flux-vector splitting (KFVS) method are also implemented to the same model. The robustness and efficiency of central upwind scheme is demonstrated by the numerical results.

  20. Capture of irregular satellites at Jupiter

    International Nuclear Information System (INIS)

    Nesvorný, David; Vokrouhlický, David; Deienno, Rogerio

    2014-01-01

    The irregular satellites of outer planets are thought to have been captured from heliocentric orbits. The exact nature of the capture process, however, remains uncertain. We examine the possibility that irregular satellites were captured from the planetesimal disk during the early solar system instability when encounters between the outer planets occurred. Nesvorný et al. already showed that the irregular satellites of Saturn, Uranus, and Neptune were plausibly captured during planetary encounters. Here we find that the current instability models present favorable conditions for capture of irregular satellites at Jupiter as well, mainly because Jupiter undergoes a phase of close encounters with an ice giant. We show that the orbital distribution of bodies captured during planetary encounters provides a good match to the observed distribution of irregular satellites at Jupiter. The capture efficiency for each particle in the original transplanetary disk is found to be (1.3-3.6) × 10 –8 . This is roughly enough to explain the observed population of jovian irregular moons. We also confirm Nesvorný et al.'s results for the irregular satellites of Saturn, Uranus, and Neptune.

  1. Electron capture and transfer-ionization processes in {sup 4}He{sup 2+}+Ar collision at 12.5 keV amu{sup -1}

    Energy Technology Data Exchange (ETDEWEB)

    Moretto-Capelle, P.; Bordenave-Montesquieu, D.; Bordenave-Montesquieu, A.; Benhenni, M. [Laboratoire Collisions, Agregats, Reactivite, IRSAMC, UMR 5589 CNRS and Universite Paul Sabatier, 31062 Toulouse Cedex (France)

    1998-05-14

    Electron emission in the {sup 4}He{sup 2+}+Ar collisional system has been investigated at 35 deg. and 12.5 keV amu{sup -1} collision velocity, in coincidence with the recoil target ion charges. Direct single ionization is found to be negligible with respect to single-electron capture. Contributions of transfer-ionization processes are stressed in the production of Ar{sup 2+} to Ar{sup 4+} ions; those of direct ionization, double excitation of the target and double capture into autoionization states of helium are instead found to be much less probable. Among the two-electron processes which explain the formation of Ar{sup 2+} ions, the double capture into autoionizing states of helium remains unimportant with respect to a pure transfer ionization process (one captured electron plus one ionized electron). The measured predominant production of Ar{sup 3+} ions illustrates the role played by three-electron processes, mainly a two-electron transfer accompanied by a single-target ionization. Finally, the formation of Ar{sup 4+} ions is connected with more complex transfer ionization processes. A qualitative analysis of these results is made within the quasimolecular approach. (author). Letter-to-the-editor.

  2. Self-face Captures, Holds, and Biases Attention.

    Science.gov (United States)

    Wójcik, Michał J; Nowicka, Maria M; Kotlewska, Ilona; Nowicka, Anna

    2017-01-01

    The implicit self-recognition process may take place already in the pre-attentive stages of perception. After a silent stimulus has captured attention, it is passed on to the attentive stage where it can affect decision making and responding. Numerous studies show that the presence of self-referential information affects almost every cognitive level. These effects may share a common and fundamental basis in an attentional mechanism, conceptualized as attentional bias: the exaggerated deployment of attentional resources to a salient stimulus. A gold standard in attentional bias research is the dot-probe paradigm. In this task, a prominent stimulus (cue) and a neutral stimulus are presented in different spatial locations, followed by the presentation of a target. In the current study we aimed at investigating whether the self-face captures, holds and biases attention when presented as a task-irrelevant stimulus. In two dot-probe experiments coupled with the event-related potential (ERP) technique we analyzed the following relevant ERPs components: N2pc and SPCN which reflect attentional shifts and the maintenance of attention, respectively. An inter-stimulus interval separating face-cues and probes (800 ms) was introduced only in the first experiment. In line with our predictions, in Experiment 1 the self-face elicited the N2pc and the SPCN component. In Experiment 2 in addition to N2pc, an attentional bias was observed. Our results indicate that unintentional self-face processing disables the top-down control setting to filter out distractors, thus leading to the engagement of attentional resources and visual short-term memory.

  3. Self-face Captures, Holds, and Biases Attention

    Directory of Open Access Journals (Sweden)

    Michał J. Wójcik

    2018-01-01

    Full Text Available The implicit self-recognition process may take place already in the pre-attentive stages of perception. After a silent stimulus has captured attention, it is passed on to the attentive stage where it can affect decision making and responding. Numerous studies show that the presence of self-referential information affects almost every cognitive level. These effects may share a common and fundamental basis in an attentional mechanism, conceptualized as attentional bias: the exaggerated deployment of attentional resources to a salient stimulus. A gold standard in attentional bias research is the dot-probe paradigm. In this task, a prominent stimulus (cue and a neutral stimulus are presented in different spatial locations, followed by the presentation of a target. In the current study we aimed at investigating whether the self-face captures, holds and biases attention when presented as a task-irrelevant stimulus. In two dot-probe experiments coupled with the event-related potential (ERP technique we analyzed the following relevant ERPs components: N2pc and SPCN which reflect attentional shifts and the maintenance of attention, respectively. An inter-stimulus interval separating face-cues and probes (800 ms was introduced only in the first experiment. In line with our predictions, in Experiment 1 the self-face elicited the N2pc and the SPCN component. In Experiment 2 in addition to N2pc, an attentional bias was observed. Our results indicate that unintentional self-face processing disables the top-down control setting to filter out distractors, thus leading to the engagement of attentional resources and visual short-term memory.

  4. Selecting numerical scales for pairwise comparisons

    International Nuclear Information System (INIS)

    Elliott, Michael A.

    2010-01-01

    It is often desirable in decision analysis problems to elicit from an individual the rankings of a population of attributes according to the individual's preference and to understand the degree to which each attribute is preferred to the others. A common method for obtaining this information involves the use of pairwise comparisons, which allows an analyst to convert subjective expressions of preference between two attributes into numerical values indicating preferences across the entire population of attributes. Key to the use of pairwise comparisons is the underlying numerical scale that is used to convert subjective linguistic expressions of preference into numerical values. This scale represents the psychological manner in which individuals perceive increments of preference among abstract attributes and it has important implications about the distribution and consistency of an individual's preferences. Three popular scale types, the traditional integer scales, balanced scales and power scales are examined. Results of a study of 64 individuals responding to a hypothetical decision problem show that none of these scales can accurately capture the preferences of all individuals. A study of three individuals working on an actual engineering decision problem involving the design of a decay heat removal system for a nuclear fission reactor show that the choice of scale can affect the preferred decision. It is concluded that applications of pairwise comparisons would benefit from permitting participants to choose the scale that best models their own particular way of thinking about the relative preference of attributes.

  5. CO2 Capture and Reuse

    International Nuclear Information System (INIS)

    Thambimuthu, K.; Gupta, M.; Davison, J.

    2003-01-01

    CO2 capture and storage including its utilization or reuse presents an opportunity to achieve deep reductions in greenhouse gas emissions from fossil energy use. The development and deployment of this option could significantly assist in meeting a future goal of achieving stabilization of the presently rising atmospheric concentration of greenhouse gases. CO2 capture from process streams is an established concept that has achieved industrial practice. Examples of current applications include the use of primarily, solvent based capture technologies for the recovery of pure CO2 streams for chemical synthesis, for utilization as a food additive, for use as a miscible agent in enhanced oil recovery operations and removal of CO2 as an undesired contaminant from gaseous process streams for the production of fuel gases such as hydrogen and methane. In these applications, the technologies deployed for CO2 capture have focused on gas separation from high purity, high pressure streams and in reducing (or oxygen deficient) environments, where the energy penalties and cost for capture are moderately low. However, application of the same capture technologies for large scale abatement of greenhouse gas emissions from fossil fuel use poses significant challenges in achieving (at comparably low energy penalty and cost) gas separation in large volume, dilute concentration and/or low pressure flue gas streams. This paper will focus on a review of existing commercial methods of CO2 capture and the technology stretch, process integration and energy system pathways needed for their large scale deployment in fossil fueled processes. The assessment of potential capture technologies for the latter purpose will also be based on published literature data that are both 'transparent' and 'systematic' in their evaluation of the overall cost and energy penalties of CO2 capture. In view of the of the fact that many of the existing commercial processes for CO2 capture have seen applications in

  6. Almost Surely Asymptotic Stability of Exact and Numerical Solutions for Neutral Stochastic Pantograph Equations

    Directory of Open Access Journals (Sweden)

    Zhanhua Yu

    2011-01-01

    Full Text Available We study the almost surely asymptotic stability of exact solutions to neutral stochastic pantograph equations (NSPEs, and sufficient conditions are obtained. Based on these sufficient conditions, we show that the backward Euler method (BEM with variable stepsize can preserve the almost surely asymptotic stability. Numerical examples are demonstrated for illustration.

  7. Numerical approximation of null controls for the heat equation: Ill-posedness and remedies

    International Nuclear Information System (INIS)

    Münch, Arnaud; Zuazua, Enrique

    2010-01-01

    minimal L 2 -norm exhibit a singular highly oscillatory behavior near the final controllability time, which cannot be captured numerically. Standard techniques, such as Tychonoff's regularization or quasi-reversibility methods, allow a slight smoothing of the singularities but significantly reduce the quality of the approximation. In this paper we develop some more involved and less-standard approaches which turn out to be more efficient. We first discuss the advantages of using controls with compact support with respect to the time variable or the effect of adding numerical dissipative singular terms. We also develop the numerical version of the so-called transmutation method that allows writing the control of a heat process in terms of the corresponding control of the associated wave process, by means of a 'time convolution' with a one-dimensional controlled fundamental heat solution. This method, although it can be proved to converge, is also subtle in its computational implementation. Indeed, it requires using convergent numerical schemes for the control of the wave equation, a problem that, as mentioned above, is delicate in itself. But we also need to compute an accurate approximation of a controlled fundamental heat solution, an issue that requires its own analysis and significant numerical and computational new developments. These methods are thoroughly illustrated and discussed in the paper, accompanied by some numerical experiments in one space dimension that show the subtlety of the issue. These experiments allow one to compare the efficiency of the various methods. This is done in the case where the control is distributed in some subdomain of the domain where the heat process evolves but similar results and numerical experiments could be derived for other cases, such as the one in which the control acts on the boundary. The techniques we employ here can also be adapted to the multi-dimensional case

  8. Numerical simulation of a hovering rotor using embedded grids

    Science.gov (United States)

    Duque, Earl-Peter N.; Srinivasan, Ganapathi R.

    1992-01-01

    The flow field for a rotor blade in hover was computed by numerically solving the compressible thin-layer Navier-Stokes equations on embedded grids. In this work, three embedded grids were used to discretize the flow field - one for the rotor blade and two to convect the rotor wake. The computations were performed at two hovering test conditions, for a two-bladed rectangular rotor of aspect ratio six. The results compare fairly with experiment and illustrates the use of embedded grids in solving helicopter type flow fields.

  9. Numerical simulation of bubble deformation in magnetic fluids by finite volume method

    International Nuclear Information System (INIS)

    Yamasaki, Haruhiko; Yamaguchi, Hiroshi

    2017-01-01

    Bubble deformation in magnetic fluids under magnetic field is investigated numerically by an interface capturing method. The numerical method consists of a coupled level-set and VOF (Volume of Fluid) method, combined with conservation CIP (Constrained Interpolation Profile) method with the self-correcting procedure. In the present study considering actual physical properties of magnetic fluid, bubble deformation under given uniform magnetic field is analyzed for internal magnetic field passing through a magnetic gaseous and liquid phase interface. The numerical results explain the mechanism of bubble deformation under presence of given magnetic field. - Highlights: • A magnetic field analysis is developed to simulate the bubble dynamics in magnetic fluid with two-phase interface. • The elongation of bubble increased with increasing magnetic flux intensities due to strong magnetic normal force. • Proposed technique explains the bubble dynamics, taking into account of the continuity of the magnetic flux density.

  10. From blackbirds to black holes: Investigating capture-recapture methods for time domain astronomy

    Science.gov (United States)

    Laycock, Silas G. T.

    2017-07-01

    In time domain astronomy, recurrent transients present a special problem: how to infer total populations from limited observations. Monitoring observations may give a biassed view of the underlying population due to limitations on observing time, visibility and instrumental sensitivity. A similar problem exists in the life sciences, where animal populations (such as migratory birds) or disease prevalence, must be estimated from sparse and incomplete data. The class of methods termed Capture-Recapture is used to reconstruct population estimates from time-series records of encounters with the study population. This paper investigates the performance of Capture-Recapture methods in astronomy via a series of numerical simulations. The Blackbirds code simulates monitoring of populations of transients, in this case accreting binary stars (neutron star or black hole accreting from a stellar companion) under a range of observing strategies. We first generate realistic light-curves for populations of binaries with contrasting orbital period distributions. These models are then randomly sampled at observing cadences typical of existing and planned monitoring surveys. The classical capture-recapture methods, Lincoln-Peterson, Schnabel estimators, related techniques, and newer methods implemented in the Rcapture package are compared. A general exponential model based on the radioactive decay law is introduced which is demonstrated to recover (at 95% confidence) the underlying population abundance and duty cycle, in a fraction of the observing visits (10-50%) required to discover all the sources in the simulation. Capture-Recapture is a promising addition to the toolbox of time domain astronomy, and methods implemented in R by the biostats community can be readily called from within python.

  11. Automatic Generation of Stippling Illustrations from two Photographs

    Directory of Open Access Journals (Sweden)

    Germán Arroyo

    2012-05-01

    This tool needs almost no user interaction. The user simply has to align both photographs and indicate the level of detail according to the distance. The rest is decided by our software. Whereas a professional illustrator needs more than 20 hours to finish a similar illustration, our software is able to do it in just few seconds.

  12. Confusion noise from LISA capture sources

    International Nuclear Information System (INIS)

    Barack, Leor; Cutler, Curt

    2004-01-01

    Captures of compact objects (COs) by massive black holes (MBHs) in galactic nuclei will be an important source for LISA, the proposed space-based gravitational wave (GW) detector. However, a large fraction of captures will not be individually resolvable - either because they are too distant, have unfavorable orientation, or have too many years to go before final plunge - and so will constitute a source of 'confusion noise', obscuring other types of sources. In this paper we estimate the shape and overall magnitude of the GW background energy spectrum generated by CO captures. This energy spectrum immediately translates to a spectral density S h capt (f) for the amplitude of capture-generated GWs registered by LISA. The overall magnitude of S h capt (f) is linear in the CO capture rates, which are rather uncertain; therefore we present results for a plausible range of rates. S h capt (f) includes the contributions from both resolvable and unresolvable captures, and thus represents an upper limit on the confusion noise level. We then estimate what fraction of S h capt (f) is due to unresolvable sources and hence constitutes confusion noise. We find that almost all of the contribution to S h capt (f) coming from white dwarf and neutron star captures, and at least ∼30% of the contribution from black hole captures, is from sources that cannot be individually resolved. Nevertheless, we show that the impact of capture confusion noise on the total LISA noise curve ranges from insignificant to modest, depending on the rates. Capture rates at the high end of estimated ranges would raise LISA's overall (effective) noise level [fS h eff (f)] 1/2 by at most a factor ∼2 in the frequency range 1-10 mHz, where LISA is most sensitive. While this slightly elevated noise level would somewhat decrease LISA's sensitivity to other classes of sources, we argue that, overall, this would be a pleasant problem for LISA to have: It would also imply that detection rates for CO captures

  13. Nuclear muon capture

    CERN Document Server

    Mukhopadhyay, N C

    1977-01-01

    Our present knowledge of the nuclear muon capture reactions is surveyed. Starting from the formation of the muonic atom, various phenomena, having a bearing on the nuclear capture, are reviewed. The nuclear reactions are then studied from two angles-to learn about the basic muon+nucleon weak interaction process, and to obtain new insights on the nuclear dynamics. Future experimental prospects with the newer generation muon 'factories' are critically examined. Possible modification of the muon+nucleon weak interaction in complex nuclei remains the most important open problem in this field. (380 refs).

  14. Experimental and numerical investigations of shape memory alloy helical springs

    International Nuclear Information System (INIS)

    Aguiar, Ricardo A A; Pacheco, Pedro M C L; Savi, Marcelo A

    2010-01-01

    Shape memory alloys (SMAs) belong to the class of smart materials and have been used in numerous applications. Solid phase transformations induced either by stress or temperature are behind the remarkable properties of SMAs that motivate the concept of innovative smart actuators for different purposes. The SMA element used in these actuators can assume different forms and a spring is an element usually employed for this aim. This contribution deals with the modeling, simulation and experimental analysis of SMA helical springs. Basically, a one-dimensional constitutive model is assumed to describe the SMA thermomechanical shear behavior and, afterwards, helical springs are modeled by considering a classical approach for linear-elastic springs. A numerical method based on the operator split technique is developed. SMA helical spring thermomechanical behavior is investigated through experimental tests performed with different thermomechanical loadings. Shape memory and pseudoelastic effects are treated. Numerical simulations show that the model results are in close agreement with those obtained by experimental tests, revealing that the proposed model captures the general thermomechanical behavior of SMA springs

  15. Numerical solution to the hermitian Yang-Mills equation on the Fermat quintic

    International Nuclear Information System (INIS)

    Douglas, Michael R.; Karp, Robert L.; Lukic, Sergio; Reinbacher, Rene

    2007-01-01

    We develop an iterative method for finding solutions to the hermitian Yang-Mills equation on stable holomorphic vector bundles, following ideas recently developed by Donaldson. As illustrations, we construct numerically the hermitian Einstein metrics on the tangent bundle and a rank three vector bundle on P 2 . In addition, we find a hermitian Yang-Mills connection on a stable rank three vector bundle on the Fermat quintic

  16. Testability of numerical systems

    International Nuclear Information System (INIS)

    Soulas, B.

    1992-01-01

    In order to face up to the growing complexity of systems, the authors undertook to define a new approach for the qualification of systems. This approach is based on the concept of Testability which, supported by system modelization, validation and verification methods and tools, would allow Integrated Qualification process, applied throughout the life-span of systems. The general principles of this approach are introduced in the general case of numerical systems; in particular, this presentation points out the difference between the specification activity and the modelization and validation activity. This approach is illustrated firstly by the study of a global system and then by case of communication protocol as the software point of view. Finally MODEL which support this approach is described. MODEL tool is a commercial tool providing modelization and validation techniques based on Petri Nets with triple extension: Predicate/Transition, Timed and Stochastic Petri Nets

  17. Children’s Book Illustrations: Visual Language of Picture Books

    Directory of Open Access Journals (Sweden)

    Hladíková Hana

    2014-01-01

    Full Text Available High-quality picture books that merge text and illustration together in order to tell a story are eminent for healthy mental and social growth of children. This paper is to outline the benefits picture books bring to children between the ages three to eight, determine functions of its illustrative language, examine the process of its production, and point out a set of elements that, according to number of professional children's book illustrators, significantly contribute to the success of a picture book

  18. Nucleic acid hybridization assays employing dA-tailed capture probes. II. Advanced multiple capture methods

    International Nuclear Information System (INIS)

    Hunsaker, W.R.; Badri, H.; Lombardo, M.; Collins, M.L.

    1989-01-01

    A fourth capture is added to the reversible target capture procedure. This results in an improved radioisotopic detection limit of 7.3 x 10(-21) mol of target. In addition, the standard triple capture method is converted into a nonradioactive format with a detection limit of under 1 amol of target. The principal advantage of nonradioactive detection is that the entire assay can be performed in about 1 h. Nucleic acids are released from cells in the presence of the (capture probe) which contains a 3'-poly(dA) sequence and the (labeled probe) which contains a detectable nonradioactive moiety such as biotin. After a brief hybridization in solution, the target is captured on oligo(dT) magnetic particles. The target is further purified from sample impurities and excess labeled probe by recapture either once or twice more on fresh magnetic particles. The highly purified target is then concentrated to 200 nl by recapture onto a poly(dT) nitrocellulose filter and rapidly detected with streptavidin-alkaline phosphatase using bromochloroindolyl phosphate and nitroblue tetrazolium. Using this procedure, as little as 0.25 amol of a target plasmid has been detected nonradioactively in crude samples in just 1 h without prior purification of the DNA and RNA. Finally, a new procedure called background capture is introduced to complement the background-reducing power of RTC

  19. The Effectiveness of Classroom Capture Technology

    Science.gov (United States)

    Ford, Maire B.; Burns, Colleen E.; Mitch, Nathan; Gomez, Melissa M.

    2012-01-01

    The use of classroom capture systems (systems that capture audio and video footage of a lecture and attempt to replicate a classroom experience) is becoming increasingly popular at the university level. However, research on the effectiveness of classroom capture systems in the university classroom has been limited due to the recent development and…

  20. Contingent orienting or contingent capture: a size singleton matching the target-distractor size relation cannot capture attention.

    Science.gov (United States)

    Du, Feng; Yin, Yue; Qi, Yue; Zhang, Kan

    2014-08-01

    In the present study, we examined whether a peripheral size-singleton distractor that matches the target-distractor size relation can capture attention and disrupt central target identification. Three experiments consistently showed that a size singleton that matches the target-distractor size relation cannot capture attention when it appears outside of the attentional window, even though the same size singleton produces a cuing effect. In addition, a color singleton that matches the target color, instead of a size singleton that matches the target-distractor size relation, captures attention when it is outside of the attentional window. Thus, a size-relation-matched distractor is much weaker than a color-matched distractor in capturing attention and cannot capture attention when the distractor appears outside of the attentional window.

  1. Illustrating and Designing Quranic Imagery

    Science.gov (United States)

    Almenoar, Lubna

    2009-01-01

    Selected verses from Abdullah Yusuf Ali's English language translation of the meaning of the Quran have been used as a literary text to teach both descriptive and figurative imagery (including similes, metaphors and symbols) to students at the undergraduate level in an Islamic institution. The technique--Illustrating and Designing for teaching…

  2. The Use of Pictorial Illustrations in African Language Dictionaries

    Directory of Open Access Journals (Sweden)

    Lilian Gangla-Birir

    2011-10-01

    Full Text Available

    ABSTRACT: This article examines the use of pictorial illustrations in African language dictionar-ies, with particular reference to items generally included in dictionaries based on Stein's (1991 categories. It argues for the need to include more illustrations of cultural items specific to a par-ticular community and language group in dictionaries. A corpus analytic survey is done to deter-mine if African language dictionaries employ pictorial illustrations and, if so, which items are illus-trated. The results of this survey indicate that only a few African language dictionaries employ pictorial illustrations, even those that do correspond to Stein's categories. Of the dictionaries exam-ined, only one uses illustrations in the form of full-colour photographs, namely of different kinds of cattle, a very important cultural item within that specific community.


    Keywords: PICTORIAL ILLUSTRATIONS, CULTURE, LEXICOGRAPHY, BILINGUAL DIC-TIONARY, MONOLINGUAL DICTIONARY, AFRICAN LANGUAGE

    *****

    OPSOMMING: Die gebruik van beeldillustrasies in Afrikataalwoordeboeke. Hierdie artikel ondersoek die gebruik van beeldillustrasies in Afrikataalwoordeboeke met spesiale verwysing na items wat gewoonlik in woordeboeke ingesluit word, gebaseer op Stein (1991 se kategorieë. Dit betoog vir die noodsaaklikheid om meer illustrasies van kulturele items eie aan 'n besondere gemeenskap of taalgroep in woordeboeke in te sluit. 'n Analitiese oorsig van 'n korpus is gedoen om te bepaal of Afrikataalwoordeboeke beeldillustrasies gebruik, en, indien wel, watter items geïllustreer word. Die resultate van hierdie oorsig toon aan dat slegs 'n paar Afrikataalwoor-deboeke beeldillustrasies gebruik, selfs dié wat met Stein se kategorieë ooreenstem. Van die woor-deboeke wat ondersoek is, gebruik net een illustrasies in die vorm van volkleurfoto's, naamlik van verskillende soorte beeste, 'n baie belangrike kulturele item binne daardie spesifieke gemeenskap

  3. Capture cross sections on unstable nuclei

    Science.gov (United States)

    Tonchev, A. P.; Escher, J. E.; Scielzo, N.; Bedrossian, P.; Ilieva, R. S.; Humby, P.; Cooper, N.; Goddard, P. M.; Werner, V.; Tornow, W.; Rusev, G.; Kelley, J. H.; Pietralla, N.; Scheck, M.; Savran, D.; Löher, B.; Yates, S. W.; Crider, B. P.; Peters, E. E.; Tsoneva, N.; Goriely, S.

    2017-09-01

    Accurate neutron-capture cross sections on unstable nuclei near the line of beta stability are crucial for understanding the s-process nucleosynthesis. However, neutron-capture cross sections for short-lived radionuclides are difficult to measure due to the fact that the measurements require both highly radioactive samples and intense neutron sources. Essential ingredients for describing the γ decays following neutron capture are the γ-ray strength function and level densities. We will compare different indirect approaches for obtaining the most relevant observables that can constrain Hauser-Feshbach statistical-model calculations of capture cross sections. Specifically, we will consider photon scattering using monoenergetic and 100% linearly polarized photon beams. Challenges that exist on the path to obtaining neutron-capture cross sections for reactions on isotopes near and far from stability will be discussed.

  4. Capture cross sections on unstable nuclei

    Directory of Open Access Journals (Sweden)

    Tonchev A.P.

    2017-01-01

    Full Text Available Accurate neutron-capture cross sections on unstable nuclei near the line of beta stability are crucial for understanding the s-process nucleosynthesis. However, neutron-capture cross sections for short-lived radionuclides are difficult to measure due to the fact that the measurements require both highly radioactive samples and intense neutron sources. Essential ingredients for describing the γ decays following neutron capture are the γ-ray strength function and level densities. We will compare different indirect approaches for obtaining the most relevant observables that can constrain Hauser-Feshbach statistical-model calculations of capture cross sections. Specifically, we will consider photon scattering using monoenergetic and 100% linearly polarized photon beams. Challenges that exist on the path to obtaining neutron-capture cross sections for reactions on isotopes near and far from stability will be discussed.

  5. The illustrated A brief history of time

    CERN Document Server

    Hawking, Stephen

    1996-01-01

    This is Stephen Hawking's updated, expanded and illustrated edition of his celebrated work which includes the most recent developments in the field, many of which were forecast by him. At the same time, he explains his complex theories through a fresh visual dimension. Over one hunded and fifty stunning colour illustrations have been specially commissioned for this purpose to help the reader understand what have become popular mythic images of our century, but which nonetheless remain difficult, abstract ideas to grasp. It includes a new introduction written specially for this edition.

  6. Evaluation of deconvolution modelling applied to numerical combustion

    Science.gov (United States)

    Mehl, Cédric; Idier, Jérôme; Fiorina, Benoît

    2018-01-01

    A possible modelling approach in the large eddy simulation (LES) of reactive flows is to deconvolve resolved scalars. Indeed, by inverting the LES filter, scalars such as mass fractions are reconstructed. This information can be used to close budget terms of filtered species balance equations, such as the filtered reaction rate. Being ill-posed in the mathematical sense, the problem is very sensitive to any numerical perturbation. The objective of the present study is to assess the ability of this kind of methodology to capture the chemical structure of premixed flames. For that purpose, three deconvolution methods are tested on a one-dimensional filtered laminar premixed flame configuration: the approximate deconvolution method based on Van Cittert iterative deconvolution, a Taylor decomposition-based method, and the regularised deconvolution method based on the minimisation of a quadratic criterion. These methods are then extended to the reconstruction of subgrid scale profiles. Two methodologies are proposed: the first one relies on subgrid scale interpolation of deconvolved profiles and the second uses parametric functions to describe small scales. Conducted tests analyse the ability of the method to capture the chemical filtered flame structure and front propagation speed. Results show that the deconvolution model should include information about small scales in order to regularise the filter inversion. a priori and a posteriori tests showed that the filtered flame propagation speed and structure cannot be captured if the filter size is too large.

  7. Numerical modeling of large field-induced strains in ferroelastic bodies: a continuum approach

    International Nuclear Information System (INIS)

    Raikher, Yu L; Stolbov, O V

    2008-01-01

    A consistent continuum model of a soft magnetic elastomer (SME) is presented and developed for the case of finite strain. The numeric algorithm enabling one to find the field-induced shape changes of an SME body is described. The reliability of the method is illustrated by several examples revealing specifics of the magnetostriction effect in SME samples of various geometries

  8. Developing hospital identity manuals: a reference tool for illustrators.

    Science.gov (United States)

    Schaffer, J A; Zimmerman, S B

    1990-01-01

    Because of an increase in hospital marketing efforts, medical illustrators may be asked to assist in developing and implementing hospital identity manuals, which specify the graphic standards for visual communications media. A checklist survey of existing identity manuals and a literature review were conducted by one of the authors, a medical illustrator, to help her to develop a manual for her hospital employer. This article documents the literature review, the study, and the identity manual development, and presents recommendations to help other medical illustrators who might become involved in similar assignments.

  9. Circular orbits of corotating binary black holes: Comparison between analytical and numerical results

    International Nuclear Information System (INIS)

    Damour, Thibault; Gourgoulhon, Eric; Grandclement, Philippe

    2002-01-01

    We compare recent numerical results, obtained within a 'helical Killing vector' approach, on circular orbits of corotating binary black holes to the analytical predictions made by the effective one-body (EOB) method (which has been recently extended to the case of spinning bodies). On the scale of the differences between the results obtained by different numerical methods, we find good agreement between numerical data and analytical predictions for several invariant functions describing the dynamical properties of circular orbits. This agreement is robust against the post-Newtonian accuracy used for the analytical estimates, as well as under choices of the resummation method for the EOB 'effective potential', and gets better as one uses a higher post-Newtonian accuracy. These findings open the way to a significant 'merging' of analytical and numerical methods, i.e. to matching an EOB-based analytical description of the (early and late) inspiral, up to the beginning of the plunge, to a numerical description of the plunge and merger. We illustrate also the 'flexibility' of the EOB approach, i.e. the possibility of determining some 'best fit' values for the analytical parameters by comparison with numerical data

  10. Neutron capture therapy beams at the MIT Research Reactor

    International Nuclear Information System (INIS)

    Choi, J.R.; Clement, S.D.; Harling, O.K.; Zamenhof, R.G.

    1990-01-01

    Several neutron beams that could be used for neutron capture therapy at MITR-II are dosimetrically characterized and their suitability for the treatment of glioblastoma multiforme and other types of tumors are described. The types of neutron beams studied are: (1) those filtered by various thicknesses of cadmium, D2O, 6Li, and bismuth; and (2) epithermal beams achieved by filtration with aluminum, sulfur, cadmium, 6Li, and bismuth. Measured dose vs. depth data are presented in polyethylene phantom with references to what can be expected in brain. The results indicate that both types of neutron beams are useful for neutron capture therapy. The first type of neutron beams have good therapeutic advantage depths (approximately 5 cm) and excellent in-phantom ratios of therapeutic dose to background dose. Such beams would be useful for treating tumors located at relatively shallow depths in the brain. On the other hand, the second type of neutron beams have superior therapeutic advantage depths (greater than 6 cm) and good in-phantom therapeutic advantage ratios. Such beams, when used along with bilateral irradiation schemes, would be able to treat tumors at any depth in the brain. Numerical examples of what could be achieved with these beams, using RBEs, fractionated-dose delivery, unilateral, and bilateral irradiation are presented in the paper. Finally, additional plans for further neutron beam development at MITR-II are discussed

  11. Numerical construction of 'optimal' nonoscillating amplitude and phase functions

    International Nuclear Information System (INIS)

    Matzkin, A.; Lombardi, M.

    2002-01-01

    A numerical recipe for the construction of nonoscillating amplitude and phase functions for potentials with a single minimum is given. We give different examples illustrating the recipe, showing the usefulness of the procedure for the construction of basis functions in bound-state scattering processes, such as those described by quantum defect theory. The resulting amplitude and accumulated phase functions are coined as 'optimal' nonoscillating (as a function of the space and energy variables) because they are the counterpart for the quantum problem of the classical action for the analog semiclassical problem

  12. Numerical study of nonspherical black hole accretion

    International Nuclear Information System (INIS)

    Hawley, J.F.

    1984-01-01

    This thesis describes in detail a two-dimensional, axisymmetric computer code for calculating fully relativistic ideal gas hydrodynamics around a Kerr black hole. The aim is to study fully dynamic inviscid fluid accretion onto black holes, as well as to study the evolution and development of nonlinear instabilities in pressure supported accretion disks. In order to fully calibrate and document the code, certain analytic solutions for shock tubes and special accretion flows are derived; these solutions form the basis for code testing. The numerical techniques used are developed and discussed. A variety of alternate differencing schemes are compared on an analytic test bed. Some discussion is devoted to general issues in finite differencing. The working code is calibrated using analytically solvable accretion problems, including the radial accretion of dust and of fluid with pressure (Bondi accretion). Two dimensional test problems include the spiraling infall of low angular momentum fluid, the formation of a pressure supported torus, and the stable evolution of a torus. A series of numerical models are discussed and illustrated with selected plots

  13. Theory of inelastic multiphonon scattering and carrier capture by defects in semiconductors: Application to capture cross sections

    Science.gov (United States)

    Barmparis, Georgios D.; Puzyrev, Yevgeniy S.; Zhang, X.-G.; Pantelides, Sokrates T.

    2015-12-01

    Inelastic scattering and carrier capture by defects in semiconductors are the primary causes of hot-electron-mediated degradation of power devices, which holds up their commercial development. At the same time, carrier capture is a major issue in the performance of solar cells and light-emitting diodes. A theory of nonradiative (multiphonon) inelastic scattering by defects, however, is nonexistent, while the theory for carrier capture by defects has had a long and arduous history. Here we report the construction of a comprehensive theory of inelastic scattering by defects, with carrier capture being a special case. We distinguish between capture under thermal equilibrium conditions and capture under nonequilibrium conditions, e.g., in the presence of an electrical current or hot carriers where carriers undergo scattering by defects and are described by a mean free path. In the thermal-equilibrium case, capture is mediated by a nonadiabatic perturbation Hamiltonian, originally identified by Huang and Rhys and by Kubo, which is equal to linear electron-phonon coupling to first order. In the nonequilibrium case, we demonstrate that the primary capture mechanism is within the Born-Oppenheimer approximation (adiabatic transitions), with coupling to the defect potential inducing Franck-Condon electronic transitions, followed by multiphonon dissipation of the transition energy, while the nonadiabatic terms are of secondary importance (they scale with the inverse of the mass of typical atoms in the defect complex). We report first-principles density-functional-theory calculations of the capture cross section for a prototype defect using the projector-augmented wave, which allows us to employ all-electron wave functions. We adopt a Monte Carlo scheme to sample multiphonon configurations and obtain converged results. The theory and the results represent a foundation upon which to build engineering-level models for hot-electron degradation of power devices and the performance

  14. Does imminent threat capture and hold attention?

    Science.gov (United States)

    Koster, Ernst H W; Crombez, Geert; Van Damme, Stefaan; Verschuere, Bruno; De Houwer, Jan

    2004-09-01

    According to models of attention and emotion, threat captures and holds attention. In behavioral tasks, robust evidence has been found for attentional holding but not for attentional capture by threat. An important explanation for the absence of attentional capture effects is that the visual stimuli used posed no genuine threat. The present study investigated whether visual cues that signal an aversive white noise can elicit attentional capture and holding effects. Cues presented in an attentional task were simultaneously provided with a threat value through an aversive conditioning procedure. Response latencies showed that threatening cues captured and held attention. These results support recent views on attention to threat, proposing that imminent threat captures attention in everyone. (c) 2004 APA, all rights reserved

  15. Recent development of capture of CO2

    CERN Document Server

    Chavez, Rosa Hilda

    2014-01-01

    "Recent Technologies in the capture of CO2" provides a comprehensive summary on the latest technologies available to minimize the emission of CO2 from large point sources like fossil-fuel power plants or industrial facilities. This ebook also covers various techniques that could be developed to reduce the amount of CO2 released into the atmosphere. The contents of this book include chapters on oxy-fuel combustion in fluidized beds, gas separation membrane used in post-combustion capture, minimizing energy consumption in CO2 capture processes through process integration, characterization and application of structured packing for CO2 capture, calcium looping technology for CO2 capture and many more. Recent Technologies in capture of CO2 is a valuable resource for graduate students, process engineers and administrative staff looking for real-case analysis of pilot plants. This eBook brings together the research results and professional experiences of the most renowned work groups in the CO2 capture field...

  16. Numerical methods for Bayesian inference in the face of aging

    International Nuclear Information System (INIS)

    Clarotti, C.A.; Villain, B.; Procaccia, H.

    1996-01-01

    In recent years, much attention has been paid to Bayesian methods for Risk Assessment. Until now, these methods have been studied from a theoretical point of view. Researchers have been mainly interested in: studying the effectiveness of Bayesian methods in handling rare events; debating about the problem of priors and other philosophical issues. An aspect central to the Bayesian approach is numerical computation because any safety/reliability problem, in a Bayesian frame, ends with a problem of numerical integration. This aspect has been neglected until now because most Risk studies assumed the Exponential model as the basic probabilistic model. The existence of conjugate priors makes numerical integration unnecessary in this case. If aging is to be taken into account, no conjugate family is available and the use of numerical integration becomes compulsory. EDF (National Board of Electricity, of France) and ENEA (National Committee for Energy, New Technologies and Environment, of Italy) jointly carried out a research program aimed at developing quadrature methods suitable for Bayesian Interference with underlying Weibull or gamma distributions. The paper will illustrate the main results achieved during the above research program and will discuss, via some sample cases, the performances of the numerical algorithms which on the appearance of stress corrosion cracking in the tubes of Steam Generators of PWR French power plants. (authors)

  17. An integrated movement capture and control platform applied towards autonomous movements of surgical robots.

    Science.gov (United States)

    Daluja, Sachin; Golenberg, Lavie; Cao, Alex; Pandya, Abhilash K; Auner, Gregory W; Klein, Michael D

    2009-01-01

    Robotic surgery has gradually gained acceptance due to its numerous advantages such as tremor filtration, increased dexterity and motion scaling. There remains, however, a significant scope for improvement, especially in the areas of surgeon-robot interface and autonomous procedures. Previous studies have attempted to identify factors affecting a surgeon's performance in a master-slave robotic system by tracking hand movements. These studies relied on conventional optical or magnetic tracking systems, making their use impracticable in the operating room. This study concentrated on building an intrinsic movement capture platform using microcontroller based hardware wired to a surgical robot. Software was developed to enable tracking and analysis of hand movements while surgical tasks were performed. Movement capture was applied towards automated movements of the robotic instruments. By emulating control signals, recorded surgical movements were replayed by the robot's end-effectors. Though this work uses a surgical robot as the platform, the ideas and concepts put forward are applicable to telerobotic systems in general.

  18. Validation of a numerical FSI simulation of an aortic BMHV by in vitro PIV experiments.

    Science.gov (United States)

    Annerel, S; Claessens, T; Degroote, J; Segers, P; Vierendeels, J

    2014-08-01

    In this paper, a validation of a recently developed fluid-structure interaction (FSI) coupling algorithm to simulate numerically the dynamics of an aortic bileaflet mechanical heart valve (BMHV) is performed. This validation is done by comparing the numerical simulation results with in vitro experiments. For the in vitro experiments, the leaflet kinematics and flow fields are obtained via the particle image velocimetry (PIV) technique. Subsequently, the same case is numerically simulated by the coupling algorithm and the resulting leaflet kinematics and flow fields are obtained. Finally, the results are compared, revealing great similarity in leaflet motion and flow fields between the numerical simulation and the experimental test. Therefore, it is concluded that the developed algorithm is able to capture very accurately all the major leaflet kinematics and dynamics and can be used to study and optimize the design of BMHVs. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

  19. Analyzing capture zone distributions (CZD) in growth: Theory and applications

    Science.gov (United States)

    Einstein, Theodore L.; Pimpinelli, Alberto; Luis González, Diego

    2014-09-01

    We have argued that the capture-zone distribution (CZD) in submonolayer growth can be well described by the generalized Wigner distribution (GWD) P(s) =asβ exp(-bs2), where s is the CZ area divided by its average value. This approach offers arguably the most robust (least sensitive to mass transport) method to find the critical nucleus size i, since β ≈ i + 2. Various analytical and numerical investigations, which we discuss, show that the simple GWD expression is inadequate in the tails of the distribution, it does account well for the central regime 0.5 < s < 2, where the data is sufficiently large to be reliably accessible experimentally. We summarize and catalog the many experiments in which this method has been applied.

  20. Numerical model simulation of free surface behavior in spallation target of ADS

    International Nuclear Information System (INIS)

    Chai Xiang; Su Guanyu; Cheng Xu

    2012-01-01

    The spallation target in accelerator driven sub-critical system (ADS) couples the subcritical reactor core with accelerator. The design of a windowless target has to ensure the formation of a stable free surface with desirable shape, to avoid local over- heating of the heavy liquid metal (HLM). To investigate the free surface behavior of the spallation target, OpenFOAM, an opened CFD software platform, was used to simulate the formation and features of the free surface in the windowless target. VOF method was utilized as the interface-capturing methodology. The numerical results were compared to experimental data and numerical results obtained with FLUENT code. The effects of turbulence models were studied and recommendations were made related to application of turbulence models. (authors)

  1. Development of a numerical simulation method for melting/solidification and dissolution/precipitation phenomena. 1. Literature survey for computer program design

    International Nuclear Information System (INIS)

    Uchibori, Akihiro; Ohshima, Hiroyuki

    2004-04-01

    Survey research of numerical methods for melting/solidification and dissolution/precipitation phenomena was performed to determine the policy for a simulation program development. Melting/solidification and dissolution/ precipitation have been key issues for feasibility evaluation of several techniques applied in the nuclear fuel cycle processes. Physical models for single-component melting/solidification, two-component solution solidification or precipitation by cooling and precipitation by electrolysis, which are moving boundary problems, were made clear from the literature survey. The transport equations are used for thermal hydraulic analysis in the solid and the liquid regions. Behavior of the solid-liquid interface is described by the heat and mass transfer model. These physical models need to be introduced into the simulation program. The numerical methods for the moving boundary problems are categorized into two types: interface tracking method and interface capturing method. Based on the classification, performance of each numerical method was evaluated. The interface tracking method using the Lagrangian moving mesh requires relatively complicated algorithm. The algorithm has high accuracy for predicting the moving interface. On the other hand, the interface capturing method uses the Eulerian fixing mesh, leading to simple algorithm. Prediction accuracy of the method is relatively low. The extended finite element method classified as the interface capturing method can predict the interface behavior accurately even though the Eulerian fixing mesh is used. We decided to apply the extended finite element method to the simulation program. (author)

  2. Selling pictures: the illustrated auction catalogue

    Directory of Open Access Journals (Sweden)

    Elizabeth Pergam

    2014-12-01

    Full Text Available This essay is based upon a survey of reproductions in auction catalogues – from their first appearance in the early eighteenth century until their more consistent use in the second decade of the twentieth century. Examining the role of these illustrations sheds light on how auctions functioned; it was not just the works of art that were traded, but knowledge about those works of art became currency to be exchanged. In contrast to the high end engravings and photographs of luxury illustrated art books, reproductions in auction catalogues – publications produced as ephemeral marketing tools – were of noticeably lower quality. This study of the status of reproductions, therefore, investigates the evolving understanding of art knowledge, both aesthetic and economic, and the interdependence of the market and connoisseurship.

  3. Enzymes in CO2 Capture

    DEFF Research Database (Denmark)

    Fosbøl, Philip Loldrup; Gladis, Arne; Thomsen, Kaj

    The enzyme Carbonic Anhydrase (CA) can accelerate the absorption rate of CO2 into aqueous solutions by several-fold. It exist in almost all living organisms and catalyses different important processes like CO2 transport, respiration and the acid-base balances. A new technology in the field...... of carbon capture is the application of enzymes for acceleration of typically slow ternary amines or inorganic carbonates. There is a hidden potential to revive currently infeasible amines which have an interesting low energy consumption for regeneration but too slow kinetics for viable CO2 capture. The aim...... of this work is to discuss the measurements of kinetic properties for CA promoted CO2 capture solvent systems. The development of a rate-based model for enzymes will be discussed showing the principles of implementation and the results on using a well-known ternary amine for CO2 capture. Conclusions...

  4. Partial radiative capture of resonance neutrons; Capture radiative partielle des neutrons de resonance

    Energy Technology Data Exchange (ETDEWEB)

    Samour, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    The radiative capture of resonance neutrons has been studied near the Saclay linac between 0.5 and 700 eV with time-of-flight method and a Ge(Li) detector. {sup 195}Pt + n and {sup 183}W + n allow the study of the distribution of partial radiative widths and their eventual correlation and also the variation of < {gamma}{sub {gamma}{sub i}} > with E{sub {gamma}}. The mean values of Ml and El transition intensities are compared in several tin isotopes. Interference effects, either between resonances or between direct capture and resonant capture are found in {sup 195}Pt + n, {sup 197}Au + n and {sup 59}Co + n. The excited level schemes of a great deal of nuclei are obtained and compared with theoretical predictions. This study has been completed by an analysis of thermal spectrum. (author) [French] La capture radiative des neutrons de resonance a ete etudiee pres de l'accelerateur lineaire de Saclay entre 0,5 et 700 eV a l'aide de la methode du temps-de-vol et d'un detecteur Ge(Li). Les noyaux {sup 195}Pt + n et {sup 183}W + n permettent l'analyse de la distribution de resonance en resonance des largeurs radiatives partielles {gamma}{sub {gamma}{sub i}} et de leur eventuelle correlation, ainsi que l'etude de la variation de < {gamma}{sub {gamma}{sub i}} > en fonction de E{sub {gamma}}. Les intensites moyennes des transitions Ml et El sont comparees pour quelques isotopes de l'etain. Des effets d'interference, soit entre resonances, soit entre capture directe et capture resonnante sont mis en evidence dans {sup 195}Pt + n, {sup 197}Au + n et {sup 59}Co + n. Enfin les schemas des etats excites d'un grand nombre de noyaux sont obtenus et compares avec les predictions theoriques. Cette etude a ete completee par une analyse des spectres thermiques. (auteur)

  5. Partial radiative capture of resonance neutrons; Capture radiative partielle des neutrons de resonance

    Energy Technology Data Exchange (ETDEWEB)

    Samour, C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    The radiative capture of resonance neutrons has been studied near the Saclay linac between 0.5 and 700 eV with time-of-flight method and a Ge(Li) detector. {sup 195}Pt + n and {sup 183}W + n allow the study of the distribution of partial radiative widths and their eventual correlation and also the variation of < {gamma}{sub {gamma}{sub i}} > with E{sub {gamma}}. The mean values of Ml and El transition intensities are compared in several tin isotopes. Interference effects, either between resonances or between direct capture and resonant capture are found in {sup 195}Pt + n, {sup 197}Au + n and {sup 59}Co + n. The excited level schemes of a great deal of nuclei are obtained and compared with theoretical predictions. This study has been completed by an analysis of thermal spectrum. (author) [French] La capture radiative des neutrons de resonance a ete etudiee pres de l'accelerateur lineaire de Saclay entre 0,5 et 700 eV a l'aide de la methode du temps-de-vol et d'un detecteur Ge(Li). Les noyaux {sup 195}Pt + n et {sup 183}W + n permettent l'analyse de la distribution de resonance en resonance des largeurs radiatives partielles {gamma}{sub {gamma}{sub i}} et de leur eventuelle correlation, ainsi que l'etude de la variation de < {gamma}{sub {gamma}{sub i}} > en fonction de E{sub {gamma}}. Les intensites moyennes des transitions Ml et El sont comparees pour quelques isotopes de l'etain. Des effets d'interference, soit entre resonances, soit entre capture directe et capture resonnante sont mis en evidence dans {sup 195}Pt + n, {sup 197}Au + n et {sup 59}Co + n. Enfin les schemas des etats excites d'un grand nombre de noyaux sont obtenus et compares avec les predictions theoriques. Cette etude a ete completee par une analyse des spectres thermiques. (auteur)

  6. Three-Dimensional Numerical Modeling of Acoustic Trapping in Glass Capillaries

    DEFF Research Database (Denmark)

    Ley, Mikkel Wennemoes Hvitfeld; Bruus, Henrik

    2017-01-01

    Acoustic traps are used to capture and handle suspended microparticles and cells in microfluidic applications. A particular simple and much-used acoustic trap consists of a commercially available, millimeter-sized, liquid-filled straight glass capillary actuated by a piezoelectric transducer. Here......, we present a three-dimensional numerical model of the acoustic pressure field in the liquid coupled to the displacement field of the glass wall, taking into account mixed standing and traveling waves as well as absorption. The model explains the dynamical mechanism that leads to the formation...

  7. Stochastic porous media modeling and high-resolution schemes for numerical simulation of subsurface immiscible fluid flow transport

    Science.gov (United States)

    Brantson, Eric Thompson; Ju, Binshan; Wu, Dan; Gyan, Patricia Semwaah

    2018-04-01

    This paper proposes stochastic petroleum porous media modeling for immiscible fluid flow simulation using Dykstra-Parson coefficient (V DP) and autocorrelation lengths to generate 2D stochastic permeability values which were also used to generate porosity fields through a linear interpolation technique based on Carman-Kozeny equation. The proposed method of permeability field generation in this study was compared to turning bands method (TBM) and uniform sampling randomization method (USRM). On the other hand, many studies have also reported that, upstream mobility weighting schemes, commonly used in conventional numerical reservoir simulators do not accurately capture immiscible displacement shocks and discontinuities through stochastically generated porous media. This can be attributed to high level of numerical smearing in first-order schemes, oftentimes misinterpreted as subsurface geological features. Therefore, this work employs high-resolution schemes of SUPERBEE flux limiter, weighted essentially non-oscillatory scheme (WENO), and monotone upstream-centered schemes for conservation laws (MUSCL) to accurately capture immiscible fluid flow transport in stochastic porous media. The high-order schemes results match well with Buckley Leverett (BL) analytical solution without any non-oscillatory solutions. The governing fluid flow equations were solved numerically using simultaneous solution (SS) technique, sequential solution (SEQ) technique and iterative implicit pressure and explicit saturation (IMPES) technique which produce acceptable numerical stability and convergence rate. A comparative and numerical examples study of flow transport through the proposed method, TBM and USRM permeability fields revealed detailed subsurface instabilities with their corresponding ultimate recovery factors. Also, the impact of autocorrelation lengths on immiscible fluid flow transport were analyzed and quantified. A finite number of lines used in the TBM resulted into visual

  8. Use of a generalized Stokes number to determine the aerodynamic capture efficiency of non-Stokesian particles from a compressible gas flow

    Science.gov (United States)

    Israel, R.; Rosner, D. E.

    1983-01-01

    The aerodynamic capture efficiency of small but nondiffusing particles suspended in a high-speed stream flowing past a target is known to be influenced by parameters governing small particle inertia, departures from the Stokes drag law, and carrier fluid compressibility. By defining an effective Stokes number in terms of the actual (prevailing) particle stopping distance, local fluid viscosity, and inviscid fluid velocity gradient at the target nose, it is shown that these effects are well correlated in terms of a 'standard' (cylindrical collector, Stokes drag, incompressible flow, sq rt Re much greater than 1) capture efficiency curve. Thus, a correlation follows that simplifies aerosol capture calculations in the parameter range already included in previous numerical solutions, allows rational engineering predictions of deposition in situations not previously specifically calculated, and should facilitate the presentation of performance data for gas cleaning equipment and aerosol instruments.

  9. Numerical simulation of nonlinear dynamical systems driven by commutative noise

    International Nuclear Information System (INIS)

    Carbonell, F.; Biscay, R.J.; Jimenez, J.C.; Cruz, H. de la

    2007-01-01

    The local linearization (LL) approach has become an effective technique for the numerical integration of ordinary, random and stochastic differential equations. One of the reasons for this success is that the LL method achieves a convenient trade-off between numerical stability and computational cost. Besides, the LL method reproduces well the dynamics of nonlinear equations for which other classical methods fail. However, in the stochastic case, most of the reported works has been focused in Stochastic Differential Equations (SDE) driven by additive noise. This limits the applicability of the LL method since there is a number of interesting dynamics observed in equations with multiplicative noise. On the other hand, recent results show that commutative noise SDEs can be transformed into a random differential equation (RDE) by means of a random diffeomorfism (conjugacy). This paper takes advantages of such conjugacy property and the LL approach for defining a LL scheme for SDEs driven by commutative noise. The performance of the proposed method is illustrated by means of numerical simulations

  10. Illustrations in Text: A Retentional Role.

    Science.gov (United States)

    Duchastel, Philippe C.

    1981-01-01

    Describes the results of a study of the retentional role of illustrations in a text and their effect on enhancing long-term memory with 15-year-old secondary school students. Seven references are listed. (CHC)

  11. Comparison of trap types and colors for capturing emerald ash borer adults at different population densities.

    Science.gov (United States)

    Poland, Therese M; Mccullough, Deborah G

    2014-02-01

    Results of numerous trials to evaluate artificial trap designs and lures for detection of Agrilus planipennis Fairmaire, the emerald ash borer, have yielded inconsistent results, possibly because of different A. planipennis population densities in the field sites. In 2010 and 2011, we compared 1) green canopy traps, 2) purple canopy traps, 3) green double-decker traps, and 4) purple double-decker traps in sites representing a range of A. planipennis infestation levels. Traps were baited with cis-3-hexenol in both years, plus an 80:20 mixture of Manuka and Phoebe oil (2010) or Manuka oil alone (2011). Condition of trees bearing canopy traps, A. planipennis infestation level of trees in the vicinity of traps, and number of A. planipennis captured per trap differed among sites in both years. Overall in both years, more females, males, and beetles of both sexes were captured on double-decker traps than canopy traps, and more beetles of both sexes (2010) or females (2011) were captured on purple traps than green traps. In 2010, detection rates were higher for purple (100%) and green double-decker traps (100%) than for purple (82%) or green canopy traps (64%) at sites with very low to low A. planipennis infestation levels. Captures of A. planipennis on canopy traps consistently increased with the infestation level of the canopy trap-bearing trees. Differences among trap types were most pronounced at sites with low A. planipennis densities, where more beetles were captured on purple double-decker traps than on green canopy traps in both years.

  12. The Numerical Analysis of Monopolistically Competitive Markets: The Case of a New York Fresh Apple Packer

    OpenAIRE

    Starbird, Sterling A.; Milligan, Robert A.

    1987-01-01

    The hypothesis is adduced that in some monopolistically competitive markets a firm's demand schedule evolves faster than the firm's marketing policies can adjust. A probabilistic model of this phenomenon is introduced. The numerical analysis of a New York fresh apple packer's inventory control policies illustrates the model's usefulness.

  13. Electron capture and stellar collapse

    International Nuclear Information System (INIS)

    Chung, K.C.

    1979-01-01

    In order, to investigate the function of electron capture in the phenomenon of pre-supernovae gravitacional collapse, an hydrodynamic caculation was carried out, coupling capture, decay and nuclear reaction equation system. A star simplified model (homogeneous model) was adopted using fermi ideal gas approximation for tthe sea of free electrons and neutrons. The non simplified treatment from quasi-static evolution to collapse is presented. The capture and beta decay rates, as wellas neutron delayed emission, were calculated by beta decay crude theory, while the other reaction rates were determined by usual theories. The preliminary results are presented. (M.C.K.) [pt

  14. Proton capture by magnetic monopoles

    International Nuclear Information System (INIS)

    Olaussen, K.; Olsen, H.A.; Oeverboe, I.; Osland, P.

    1983-09-01

    In the Kazama-Yang approximation, the lowest monopole-proton bound states have binding energies of 938 MeV, 263 keV, 105 eV, and 0.04 eV. The cross section for radiative capture to these states is for velocities β = 10 -5 - 10 -3 found to be of the order of 10 -28 - 10 -26 cm 2 . For the state that has a binding energy of 263 keV, the capture length in water is 171 x (β/10 -4 )sup(0.48) m. Observation of photons from the capture process would indicate the presence of monopoles. (orig.)

  15. A quasi-stationary numerical model of atomized metal droplets, II: Prediction and assessment

    DEFF Research Database (Denmark)

    Pryds, Nini H.; Hattel, Jesper Henri; Thorborg, Jesper

    1999-01-01

    been illustrated.A comparison between the numerical model and the experimental results shows an excellent agreement and demonstrates the validity of the present model, e.g. the calculated gas temperature which has an important influence on the droplet solidification behaviour as well as the calculated......A new model which extends previous studies and includes the interaction between enveloping gas and an array of droplets has been developed and presented in a previous paper. The model incorporates the probability density function of atomized metallic droplets into the heat transfer equations....... The main thrust of the model is that the gas temperature was not predetermined and calculated empirically but calculated numerically based on heat balance consideration. In this paper, the accuracy of the numerical model and the applicability of the model as a predictive tool have been investigated...

  16. Chronicles of progress : the illustrated newspapers of colonial Australia, 1853-1896

    OpenAIRE

    Dowling, Peter Andrew

    2017-01-01

    This thesis is a study of the imagery in the illustrated newspapers of colonial Australia over the period of their publication, 1853-1896. The distinguishing feature of these papers was that the illustrations were printed from engraved woodblocks. The thesis is pioneering in the sense that whilst historians have regularly used images from the papers to illustrate books on a wide variety of topics, no one has researched the illustrated newspapers as a primary source in their ...

  17. Analytic-numerical method of determining the freezing front location

    Directory of Open Access Journals (Sweden)

    R. Grzymkowski

    2011-07-01

    Full Text Available Mathematical modeling of thermal processes combined with the reversible phase transitions of type: solid phase – liquid phase leads to formulation of the parabolic boundary problems with the moving boundary. Solution of such defined problem requires, most often, to use sophisticated numerical techniques and far advanced mathematical tools. Excellent illustration of the complexity of considered problems, as well as of the variety of approaches used for finding their solutions, gives the papers [1-4]. In the current paper, the authors present the, especially attractive from the engineer point of view, analytic-numerical method for finding the approximate solution of selected class of problems which can be reduced to the one-phase solidification problem of a plate with the unknown a priori, varying in time boundary of the region in which the solution is sought. Proposed method is based on the known formalism of initial expansion of the sought function describing the temperature field into the power series, some coefficients of which are determined with the aid of boundary conditions, and on the approximation of the function defining the location of freezing front with the broken line, parameters of which are numerically determined.

  18. Numerical method for the nonlinear Fokker-Planck equation

    International Nuclear Information System (INIS)

    Zhang, D.S.; Wei, G.W.; Kouri, D.J.; Hoffman, D.K.

    1997-01-01

    A practical method based on distributed approximating functionals (DAFs) is proposed for numerically solving a general class of nonlinear time-dependent Fokker-Planck equations. The method relies on a numerical scheme that couples the usual path-integral concept to the DAF idea. The high accuracy and reliability of the method are illustrated by applying it to an exactly solvable nonlinear Fokker-Planck equation, and the method is compared with the accurate K-point Stirling interpolation formula finite-difference method. The approach is also used successfully to solve a nonlinear self-consistent dynamic mean-field problem for which both the cumulant expansion and scaling theory have been found by Drozdov and Morillo [Phys. Rev. E 54, 931 (1996)] to be inadequate to describe the occurrence of a long-lived transient bimodality. The standard interpretation of the transient bimodality in terms of the flat region in the kinetic potential fails for the present case. An alternative analysis based on the effective potential of the Schroedinger-like Fokker-Planck equation is suggested. Our analysis of the transient bimodality is strongly supported by two examples that are numerically much more challenging than other examples that have been previously reported for this problem. copyright 1997 The American Physical Society

  19. A robust and accurate numerical method for transcritical turbulent flows at supercritical pressure with an arbitrary equation of state

    International Nuclear Information System (INIS)

    Kawai, Soshi; Terashima, Hiroshi; Negishi, Hideyo

    2015-01-01

    This paper addresses issues in high-fidelity numerical simulations of transcritical turbulent flows at supercritical pressure. The proposed strategy builds on a tabulated look-up table method based on REFPROP database for an accurate estimation of non-linear behaviors of thermodynamic and fluid transport properties at the transcritical conditions. Based on the look-up table method we propose a numerical method that satisfies high-order spatial accuracy, spurious-oscillation-free property, and capability of capturing the abrupt variation in thermodynamic properties across the transcritical contact surface. The method introduces artificial mass diffusivity to the continuity and momentum equations in a physically-consistent manner in order to capture the steep transcritical thermodynamic variations robustly while maintaining spurious-oscillation-free property in the velocity field. The pressure evolution equation is derived from the full compressible Navier–Stokes equations and solved instead of solving the total energy equation to achieve the spurious pressure oscillation free property with an arbitrary equation of state including the present look-up table method. Flow problems with and without physical diffusion are employed for the numerical tests to validate the robustness, accuracy, and consistency of the proposed approach.

  20. Illustrations of vacuum polarization by solitons

    International Nuclear Information System (INIS)

    MacKenzie, R.; Wilczek, F.

    1984-01-01

    The value and limitations of the adiabatic method for calculating induced charges are discussed in a general way and illustrated in some simple models in 1+1 dimensions. The relevance of the size of solitons is emphasized

  1. The boundary-corrected second Born (B2B) approximation: proton-hydrogen electron capture

    International Nuclear Information System (INIS)

    Dewangan, D.P.; Bransden, B.H.

    1988-01-01

    The probability amplitude for proton-hydrogen ground-state electron capture at 125 keV in the boundary-corrected second Born approximation has been evaluated numerically by retaining all significant bound and continuum hydrogenic intermediate states for which the orbital angular momentum l ≤ 3. The differential cross section is found to be in good agreement with the experimental data for scattering angles less than about 1 mrad in the centre of mass system. The value of the boundary-corrected second Born total cross section is similar to that obtained in the boundary-corrected first Born approximation. (author)

  2. Fish welfare in capture fisheries

    NARCIS (Netherlands)

    Veldhuizen, L.J.L.; Berentsen, P.B.M.; Boer, de I.J.M.; Vis, van de J.W.; Bokkers, E.A.M.

    2018-01-01

    Concerns about the welfare of production animals have extended from farm animals to fish, but an overview of the impact of especially capture fisheries on fish welfare is lacking. This review provides a synthesis of 85 articles, which demonstrates that research interest in fish welfare in capture

  3. Numerical Analysis on the High-Strength Concrete Beams Ultimate Behaviour

    Science.gov (United States)

    Smarzewski, Piotr; Stolarski, Adam

    2017-10-01

    Development of technologies of high-strength concrete (HSC) beams production, with the aim of creating a secure and durable material, is closely linked with the numerical models of real objects. The three-dimensional nonlinear finite element models of reinforced high-strength concrete beams with a complex geometry has been investigated in this study. The numerical analysis is performed using the ANSYS finite element package. The arc-length (A-L) parameters and the adaptive descent (AD) parameters are used with Newton-Raphson method to trace the complete load-deflection curves. Experimental and finite element modelling results are compared graphically and numerically. Comparison of these results indicates the correctness of failure criteria assumed for the high-strength concrete and the steel reinforcement. The results of numerical simulation are sensitive to the modulus of elasticity and the shear transfer coefficient for an open crack assigned to high-strength concrete. The full nonlinear load-deflection curves at mid-span of the beams, the development of strain in compressive concrete and the development of strain in tensile bar are in good agreement with the experimental results. Numerical results for smeared crack patterns are qualitatively agreeable as to the location, direction, and distribution with the test data. The model was capable of predicting the introduction and propagation of flexural and diagonal cracks. It was concluded that the finite element model captured successfully the inelastic flexural behaviour of the beams to failure.

  4. A Floating Ocean Energy Conversion Device and Numerical Study on Buoy Shape and Performance

    Directory of Open Access Journals (Sweden)

    Ruiyin Song

    2016-05-01

    Full Text Available Wave and current energy can be harnessed in the East China Sea and South China Sea; however, both areas are subject to high frequencies of typhoon events. To improve the safety of the ocean energy conversion device, a Floating Ocean Energy Conversion Device (FOECD with a single mooring system is proposed, which can be towed to avoid severe ocean conditions or for regular maintenance. In this paper, the structure of the FOECD is introduced, and it includes a catamaran platform, an oscillating buoy part, a current turbine blade, hydraulic energy storage and an electrical generation part. The numerical study models the large catamaran platform as a single, large buoy, while the four floating buoys were modeled simply as small buoys. Theoretical models on wave energy power capture and efficiency were established. To improve the suitability of the buoy for use in the FOECD and its power harvesting capability, a numerical simulation of the four buoy geometries was undertaken. The shape profiles examined in this paper are cylindrical, turbinate (V-shaped and U-shaped cone with cylinder, and combined cylinder-hemisphere buoys. Simulation results reveal that the suitability of a turbinate buoy is the best of the four types. Further simulation models were carried out by adjusting the tip radius of the turbinate buoy. Three performance criteria including suitability, power harvesting capability and energy capture efficiency were analyzed. It reveals that the turbinate buoy has almost the same power harvesting capabilities and energy capture efficiency, while its suitability is far better than that of a cylindrical buoy.

  5. Numerical analysis of dynamic force spectroscopy using the torsional harmonic cantilever

    International Nuclear Information System (INIS)

    Solares, Santiago D; Hoelscher, Hendrik

    2010-01-01

    A spectral analysis method has been recently introduced by Stark et al (2002 Proc. Natl Acad. Sci. USA 99 8473-8) and implemented by Sahin et al (2007 Nat. Nanotechnol. 2 507-14) using a T-shaped cantilever design, the torsional harmonic cantilever (THC), which is capable of performing simultaneous tapping-mode atomic force microscopy imaging and force spectroscopy. Here we report on numerical simulations of the THC system using a simple dual-mass flexural-torsional model, which is applied in combination with Fourier data processing software to illustrate the spectroscopy process for quality factors corresponding to liquid, air and vacuum environments. We also illustrate the acquisition of enhanced topographical images and deformed surface contours under the application of uniform forces, and compare the results to those obtained with a previously reported linear dual-spring-mass model.

  6. Directly assessing interpersonal RSA influences in the frequency domain: An illustration with generalized partial directed coherence.

    Science.gov (United States)

    Liu, Siwei; Gates, Kathleen M; Blandon, Alysia Y

    2018-06-01

    Despite recent research indicating that interpersonal linkage in physiology is a common phenomenon during social interactions, and the well-established role of respiratory sinus arrhythmia (RSA) in socially facilitative physiological regulation, little research has directly examined interpersonal influences in RSA, perhaps due to methodological challenges in analyzing multivariate RSA data. In this article, we aim to bridge this methodological gap by introducing a new method for quantifying interpersonal RSA influences. Specifically, we show that a frequency-domain statistic, generalized partial directed coherence (gPDC), can be used to capture lagged relations in RSA between social partners without first estimating RSA for each person. We illustrate its utility by examining the relation between gPDC and marital conflict in a sample of married couples. Finally, we discuss how gPDC complements existing methods in the time domain and provide guidelines for choosing among these different statistical techniques. © 2018 Society for Psychophysiological Research.

  7. The instanton method and its numerical implementation in fluid mechanics

    Science.gov (United States)

    Grafke, Tobias; Grauer, Rainer; Schäfer, Tobias

    2015-08-01

    A precise characterization of structures occurring in turbulent fluid flows at high Reynolds numbers is one of the last open problems of classical physics. In this review we discuss recent developments related to the application of instanton methods to turbulence. Instantons are saddle point configurations of the underlying path integrals. They are equivalent to minimizers of the related Freidlin-Wentzell action and known to be able to characterize rare events in such systems. While there is an impressive body of work concerning their analytical description, this review focuses on the question on how to compute these minimizers numerically. In a short introduction we present the relevant mathematical and physical background before we discuss the stochastic Burgers equation in detail. We present algorithms to compute instantons numerically by an efficient solution of the corresponding Euler-Lagrange equations. A second focus is the discussion of a recently developed numerical filtering technique that allows to extract instantons from direct numerical simulations. In the following we present modifications of the algorithms to make them efficient when applied to two- or three-dimensional (2D or 3D) fluid dynamical problems. We illustrate these ideas using the 2D Burgers equation and the 3D Navier-Stokes equations.

  8. The instanton method and its numerical implementation in fluid mechanics

    International Nuclear Information System (INIS)

    Grafke, Tobias; Grauer, Rainer; Schäfer, Tobias

    2015-01-01

    A precise characterization of structures occurring in turbulent fluid flows at high Reynolds numbers is one of the last open problems of classical physics. In this review we discuss recent developments related to the application of instanton methods to turbulence. Instantons are saddle point configurations of the underlying path integrals. They are equivalent to minimizers of the related Freidlin–Wentzell action and known to be able to characterize rare events in such systems. While there is an impressive body of work concerning their analytical description, this review focuses on the question on how to compute these minimizers numerically. In a short introduction we present the relevant mathematical and physical background before we discuss the stochastic Burgers equation in detail. We present algorithms to compute instantons numerically by an efficient solution of the corresponding Euler–Lagrange equations. A second focus is the discussion of a recently developed numerical filtering technique that allows to extract instantons from direct numerical simulations. In the following we present modifications of the algorithms to make them efficient when applied to two- or three-dimensional (2D or 3D) fluid dynamical problems. We illustrate these ideas using the 2D Burgers equation and the 3D Navier–Stokes equations. (topical review)

  9. Heat transfer enhancement in nanofluids. A numerical approach

    International Nuclear Information System (INIS)

    Fariñas Alvariño, P; Sáiz Jabardo, J M; Arce, A; Llamas Galdo, M I

    2012-01-01

    The aim of the reported investigation is to asses the effect of brownian and thermophoretic diffusion in nanofluids convective heat transfer. In order to capture these effects, a new equation for particles distribution had to be consider. Momentum and energy equations have been reformulated in order to include brownian and thermophretic diffusion. These modes of diffusion have been suggested extensively in the literature but their effect on momentum and energy transport has not yet been numerically analyzed. In order to obtain a solution for the modified set of governing equations, a new CFD solver had to be devised. The new solver has been applied to a case study involving hydrodynamic and thermally developing laminar flow regime in a pipe. Pure base fluid solutions have been used to asses the accuracy of the model. Numerical nanofluid solutions compare reasonably well with both experimental results obtained elsewhere and the Churchill and Ozoe correlation. The observed heat transfer enhancement by the nanofluid has been attributed to its transport properties rather than to another transport mechanism.

  10. Field Testing of Cryogenic Carbon Capture

    Energy Technology Data Exchange (ETDEWEB)

    Sayre, Aaron [Sustainable Energy Solutions, LLC; Frankman, Dave [Sustainable Energy Solutions, LLC; Baxter, Andrew [Sustainable Energy Solutions, LLC; Stitt, Kyler [Sustainable Energy Solutions, LLC; Baxter, Larry [Sustainable Energy Solutions, LLC; Brigham Young Univ., Provo, UT (United States)

    2017-07-17

    Sustainable Energy Solutions has been developing Cryogenic Carbon Capture™ (CCC) since 2008. In that time two processes have been developed, the External Cooling Loop and Compressed Flue Gas Cryogenic Carbon Capture processes (CCC ECL™ and CCC CFG™ respectively). The CCC ECL™ process has been scaled up to a 1TPD CO2 system. In this process the flue gas is cooled by an external refrigerant loop. SES has tested CCC ECL™ on real flue gas slip streams from subbituminous coal, bituminous coal, biomass, natural gas, shredded tires, and municipal waste fuels at field sites that include utility power stations, heating plants, cement kilns, and pilot-scale research reactors. The CO2 concentrations from these tests ranged from 5 to 22% on a dry basis. CO2 capture ranged from 95-99+% during these tests. Several other condensable species were also captured including NO2, SO2 and PMxx at 95+%. NO was also captured at a modest rate. The CCC CFG™ process has been scaled up to a .25 ton per day system. This system has been tested on real flue gas streams including subbituminous coal, bituminous coal and natural gas at field sites that include utility power stations, heating plants, and pilot-scale research reactors. CO2 concentrations for these tests ranged from 5 to 15% on a dry basis. CO2 capture ranged from 95-99+% during these tests. Several other condensable species were also captured including NO2, SO2 and PMxx at 95+%. NO was also captured at 90+%. Hg capture was also verified and the resulting effluent from CCC CFG™ was below a 1ppt concentration. This paper will focus on discussion of the capabilities of CCC, the results of field testing and the future steps surrounding the development of this technology.

  11. The Cambridge Illustrated History of Astronomy

    Science.gov (United States)

    Hoskin, Michael

    Expertly written and lavishly illustrated, The Cambridge Illustrated History of Astronomy offers a unique account of astronomical theory and practice from antiquity to the present day. How did Moslems of the Middle Ages use astronomy to calculate the direction of Mecca from far-flung corners of the Islamic world? Who was the only ancient Greek to suspect that the earth might revolve around the sun? How did Christopher Columbus abuse his knowledge of a lunar eclipse predicted by an astronomical almanac? Packed with anecdotes and intriguing detail, this book describes how we observed the sky and interpreted what we saw at different periods of history; how this influenced our beliefs and mythology; and how great astronomers contributed to what we now know. The result is a lively and highly visual history of astronomy - a compelling read for specialists and non-specialists alike.

  12. An Effective Numerical Method and Its Utilization to Solution of Fractional Models Used in Bioengineering Applications

    Directory of Open Access Journals (Sweden)

    Petráš Ivo

    2011-01-01

    Full Text Available This paper deals with the fractional-order linear and nonlinear models used in bioengineering applications and an effective method for their numerical solution. The proposed method is based on the power series expansion of a generating function. Numerical solution is in the form of the difference equation, which can be simply applied in the Matlab/Simulink to simulate the dynamics of system. Several illustrative examples are presented, which can be widely used in bioengineering as well as in the other disciplines, where the fractional calculus is often used.

  13. Innover en illustration jeunesse : les focalisations

    Directory of Open Access Journals (Sweden)

    Anne Guibert-Lassalle

    2010-09-01

    Full Text Available L’activité éditoriale pour la jeunesse est caractérisée en France depuis 1990 par une très forte multiplication du nombre d’acteurs et un accroissement constant du nombre de publications. L’innovation est considérée comme la principale voie de survie. Ces enjeux culturels et économiques contribuent à promouvoir l’originalité de l’illustration. Pourtant le succès commercial ne couronne pas toujours les inventions graphiques. Une enquête sur l’émergence, dans les années 2000, d’une tendance porteuse, fondée sur un usage nouveau des focalisations, révèle le caractère intuitif, étroitement daté et collaboratif, de l’innovation en illustration pour la jeunesse.Innovating in illustration for the youth: the focalisationsSince 1990, publishing for the youth in France is a sector of activity where the number of actors and items produced has been constantly increased. Innovation is considered as the main way for survival. These cultural and economical stakes tend to promote originality in illustration. Since, commercial profit does not always reward graphic inventiveness. A sociological enquiry upon the emerging in the 2000’ of a successful trend, based on a fresh use of focalisations, reveals how intuitive, strictly dated and joint can be innovating in illustration for the youth.La innovación en las revistas ilustradas para jóvenes. La focalizaciónLa actividad editorial para la juventud se ha caracterizado en Francia desde 1990 por un fuerte aumento de agentes y por un crecimiento constante del número de publicaciones. La innovación es la vía esencial para sobrevivir. Las apuestas culturales y económicas contribuyen a promover la originalidad de las ilustraciones. Sin embargo el éxito comercial no siempre subraya la originalidad de estas. A principios de este siglo, una encuesta acerca de la emergencia de una tendencia prometedora, basada en una manera diferente de efectuar las focalizaciones, ha revelado el

  14. Teaching and Learning Numerical Analysis and Optimization: A Didactic Framework and Applications of Inquiry-Based Learning

    Science.gov (United States)

    Lappas, Pantelis Z.; Kritikos, Manolis N.

    2018-01-01

    The main objective of this paper is to propose a didactic framework for teaching Applied Mathematics in higher education. After describing the structure of the framework, several applications of inquiry-based learning in teaching numerical analysis and optimization are provided to illustrate the potential of the proposed framework. The framework…

  15. The Effect of Illustrations on Second Graders' Reading Comprehension.

    Science.gov (United States)

    Parisi, Gina

    A study investigated whether text illustrations improve the reading comprehension of second graders. Subjects, 14 second-grade students, read five stories from a basal reader. The control group read each story with accompanying illustrations, while the experimental group was exposed to only the written version of the same stories. Questions based…

  16. A mathematical model and numerical solution of interface problems for steady state heat conduction

    Directory of Open Access Journals (Sweden)

    Z. Muradoglu Seyidmamedov

    2006-01-01

    (isolation Ωδ tends to zero. For each case, the local truncation errors of the used conservative finite difference scheme are estimated on the nonuniform grid. A fast direct solver has been applied for the interface problems with piecewise constant but discontinuous coefficient k=k(x. The presented numerical results illustrate high accuracy and show applicability of the given approach.

  17. Illustrative Line Styles for Flow Visualization

    NARCIS (Netherlands)

    Everts, Maarten H.; Bekker, Hendrik; Roerdink, Jos B. T. M.; Isenberg, Tobias

    2011-01-01

    We present a flexible illustrative line style model for the visualization of streamline data. Our model partitions view-oriented line strips into parallel bands whose basic visual properties can be controlled independently. We thus extend previous line stylization techniques specifically for

  18. Flow Visualization using Illustrative Line Styles

    NARCIS (Netherlands)

    Everts, Maarten H.; Bekker, Hendrik; Roerdink, Jos B. T. M.; Isenberg, Tobias; Bekker, Paulus

    2011-01-01

    We present a flexible illustrative line style model for the visualization of streamline data. Our model partitions view- oriented line strips into parallel bands whose basic visual properties can be controlled independently. We thus extend previous line stylization techniques specifically for

  19. 48 CFR 9904.406-60 - Illustrations.

    Science.gov (United States)

    2010-10-01

    ... Section 9904.406-60 Federal Acquisition Regulations System COST ACCOUNTING STANDARDS BOARD, OFFICE OF FEDERAL PROCUREMENT POLICY, OFFICE OF MANAGEMENT AND BUDGET PROCUREMENT PRACTICES AND COST ACCOUNTING STANDARDS COST ACCOUNTING STANDARDS 9904.406-60 Illustrations. (a) A contractor allocates general management...

  20. 48 CFR 9904.405-60 - Illustrations.

    Science.gov (United States)

    2010-10-01

    ... Section 9904.405-60 Federal Acquisition Regulations System COST ACCOUNTING STANDARDS BOARD, OFFICE OF FEDERAL PROCUREMENT POLICY, OFFICE OF MANAGEMENT AND BUDGET PROCUREMENT PRACTICES AND COST ACCOUNTING STANDARDS COST ACCOUNTING STANDARDS 9904.405-60 Illustrations. (a) An auditor recommends disallowance of...

  1. 13 CFR 112.7 - Illustrative applications.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Illustrative applications. 112.7 Section 112.7 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION NONDISCRIMINATION IN FEDERALLY... or recruitment advertising, employment, layoff or termination, upgrading, demotion, or transfer...

  2. Dorothea Mantzel and Bernd Schulz. Francolin Illustrated School Dic

    African Journals Online (AJOL)

    rbr

    and wonder whether the Francolin Illustrated School Dictionary for Southern. Africa makes this distinction. I wonder ... The dictionary, the editors claim, is aimed at senior primary school learners who do not speak English as ... illustration of someone shooting with a bow and arrow at a target. When one turns to the headword ...

  3. Taylor bubbles at high viscosity ratios: experiments and numerical simulations

    Science.gov (United States)

    Hewakandamby, Buddhika; Hasan, Abbas; Azzopardi, Barry; Xie, Zhihua; Pain, Chris; Matar, Omar

    2015-11-01

    The Taylor bubble is a single long bubble which nearly fills the entire cross section of a liquid-filled circular tube, often occurring in gas-liquid slug flows in many industrial applications, particularly oil and gas production. The objective of this study is to investigate the fluid dynamics of three-dimensional Taylor bubble rising in highly viscous silicone oil in a vertical pipe. An adaptive unstructured mesh modelling framework is adopted here which can modify and adapt anisotropic unstructured meshes to better represent the underlying physics of bubble rising and reduce computational effort without sacrificing accuracy. The numerical framework consists of a mixed control volume and finite element formulation, a `volume of fluid'-type method for the interface-capturing based on a compressive control volume advection method, and a force-balanced algorithm for the surface tension implementation. Experimental results for the Taylor bubble shape and rise velocity are presented, together with numerical results for the dynamics of the bubbles. A comparison of the simulation predictions with experimental data available in the literature is also presented to demonstrate the capabilities of our numerical method. EPSRC Programme Grant, MEMPHIS, EP/K0039761/1.

  4. Mathematical and numerical analysis of systems of compressible hydrodynamics and photonics with polar coordinates

    International Nuclear Information System (INIS)

    Meltz, Bertrand

    2015-01-01

    This thesis deals with the mathematical and numerical analysis of the systems of compressible hydrodynamics and radiative transfer. More precisely, we study the derivation of numerical methods with 2D polar coordinates (one for the radius, one for the angle) where equations are discretized on regular polar grids. On one hand, these methods are well-suited for the simulation of flows with polar symmetries since they preserve these symmetries by construction. On the other hand, such coordinates systems introduce geometrical singularities as well as geometrical source terms which must be carefully treated. The first part of this document is devoted to the study of hydrodynamics equations, or Euler equations. We propose a new class of arbitrary high-order numerical schemes in both space and time and rely on directional splitting methods for the resolution of 2D equations. Each sub-system is solved using a Lagrange+Remap solver. We study the influence of the r=0 geometrical singularities of the cylindrical and spherical coordinates systems on the precision of the 2D numerical solutions. The second part of this document is devoted to the study of radiative transfer equations. In these equations, the unknowns depend on a large number of variables and a stiff source term is involved. The main difficulty consists in capturing the correct asymptotic behavior on coarse grids. We first construct a class of models where the radiative intensity is projected on a truncated spherical harmonics basis in order to lower the number of mathematical dimensions. Then we propose an Asymptotic Preserving scheme built in polar coordinates and we show that the scheme capture the correct diffusion limit in the radial direction as well as in the polar direction. (author) [fr

  5. Adaptive grids and numerical fluid simulations for scrape-off layer plasmas

    International Nuclear Information System (INIS)

    Klingshirn, Hans-Joachim

    2010-01-01

    Magnetic confinement nuclear fusion experiments create plasmas with local temperatures in excess of 100 million Kelvin. In these experiments the scrape-off layer, which is the plasma region in direct contact with the device wall, is of central importance both for the quality of the energy confinement and the wall material lifetime. To study the behaviour of the scrape-off layer, in addition to experiments, numerical simulations are used. This work investigates the use of adaptive discretizations of space and compatible numerical methods for scrape-off layer simulations. The resulting algorithms allow dynamic adaptation of computational grids aligned to the magnetic fields to precisely capture the strongly anisotropic energy and particle transport in the plasma. The methods are applied to the multi-fluid plasma code B2, with the goal of reducing the runtime of simulations and extending the applicability of the code.

  6. Performance estimation of a Venturi scrubber using a computational model for capturing dust particles with liquid spray

    Energy Technology Data Exchange (ETDEWEB)

    Pak, S.I. [National Fusion Research Center, 52 Eoeun-dong, Yuseong-gu, Daejeon 305-333 (Korea, Republic of)]. E-mail: paksunil@dreamwiz.com; Chang, K.S. [Department of Aerospace Engineering, KAIST, Daejeon (Korea, Republic of)]. E-mail: kschang@kaist.ac.kr

    2006-12-01

    A Venturi scrubber has dispersed three-phase flow of gas, dust, and liquid. Atomization of a liquid jet and interaction between the phases has a large effect on the performance of Venturi scrubbers. In this study, a computational model for the interactive three-phase flow in a Venturi scrubber has been developed to estimate pressure drop and collection efficiency. The Eulerian-Lagrangian method is used to solve the model numerically. Gas flow is solved using the Eulerian approach by using the Navier-Stokes equations, and the motion of dust and liquid droplets, described by the Basset-Boussinesq-Oseen (B-B-O) equation, is solved using the Lagrangian approach. This model includes interaction between gas and droplets, atomization of a liquid jet, droplet deformation, breakup and collision of droplets, and capture of dust by droplets. A circular Pease-Anthony Venturi scrubber was simulated numerically with this new model. The numerical results were compared with earlier experimental data for pressure drop and collection efficiency, and gave good agreements.

  7. Performance estimation of a Venturi scrubber using a computational model for capturing dust particles with liquid spray

    International Nuclear Information System (INIS)

    Pak, S.I.; Chang, K.S.

    2006-01-01

    A Venturi scrubber has dispersed three-phase flow of gas, dust, and liquid. Atomization of a liquid jet and interaction between the phases has a large effect on the performance of Venturi scrubbers. In this study, a computational model for the interactive three-phase flow in a Venturi scrubber has been developed to estimate pressure drop and collection efficiency. The Eulerian-Lagrangian method is used to solve the model numerically. Gas flow is solved using the Eulerian approach by using the Navier-Stokes equations, and the motion of dust and liquid droplets, described by the Basset-Boussinesq-Oseen (B-B-O) equation, is solved using the Lagrangian approach. This model includes interaction between gas and droplets, atomization of a liquid jet, droplet deformation, breakup and collision of droplets, and capture of dust by droplets. A circular Pease-Anthony Venturi scrubber was simulated numerically with this new model. The numerical results were compared with earlier experimental data for pressure drop and collection efficiency, and gave good agreements

  8. Performance estimation of a Venturi scrubber using a computational model for capturing dust particles with liquid spray.

    Science.gov (United States)

    Pak, S I; Chang, K S

    2006-12-01

    A Venturi scrubber has dispersed three-phase flow of gas, dust, and liquid. Atomization of a liquid jet and interaction between the phases has a large effect on the performance of Venturi scrubbers. In this study, a computational model for the interactive three-phase flow in a Venturi scrubber has been developed to estimate pressure drop and collection efficiency. The Eulerian-Lagrangian method is used to solve the model numerically. Gas flow is solved using the Eulerian approach by using the Navier-Stokes equations, and the motion of dust and liquid droplets, described by the Basset-Boussinesq-Oseen (B-B-O) equation, is solved using the Lagrangian approach. This model includes interaction between gas and droplets, atomization of a liquid jet, droplet deformation, breakup and collision of droplets, and capture of dust by droplets. A circular Pease-Anthony Venturi scrubber was simulated numerically with this new model. The numerical results were compared with earlier experimental data for pressure drop and collection efficiency, and gave good agreements.

  9. Materials For Gas Capture, Methods Of Making Materials For Gas Capture, And Methods Of Capturing Gas

    KAUST Repository

    Polshettiwar, Vivek; Patil, Umesh

    2013-01-01

    In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein, embodiments of the present disclosure, in one aspect, relate to materials that can be used for gas (e.g., CO.sub.2) capture, methods of making

  10. Predicting individual differences in decision-making process from signature movement styles: an illustrative study of leaders.

    Science.gov (United States)

    Connors, Brenda L; Rende, Richard; Colton, Timothy J

    2013-01-01

    There has been a surge of interest in examining the utility of methods for capturing individual differences in decision-making style. We illustrate the potential offered by Movement Pattern Analysis (MPA), an observational methodology that has been used in business and by the US Department of Defense to record body movements that provide predictive insight into individual differences in decision-making motivations and actions. Twelve military officers participated in an intensive 2-h interview that permitted detailed and fine-grained observation and coding of signature movements by trained practitioners using MPA. Three months later, these subjects completed four hypothetical decision-making tasks in which the amount of information sought out before coming to a decision, as well as the time spent on the tasks, were under the partial control of the subject. A composite MPA indicator of how a person allocates decision-making actions and motivations to balance both Assertion (exertion of tangible movement effort on the environment to make something occur) and Perspective (through movements that support shaping in the body to perceive and create a suitable viewpoint for action) was highly correlated with the total number of information draws and total response time-individuals high on Assertion reached for less information and had faster response times than those high on Perspective. Discussion focuses on the utility of using movement-based observational measures to capture individual differences in decision-making style and the implications for application in applied settings geared toward investigations of experienced leaders and world statesmen where individuality rules the day.

  11. Predicting Individual Differences in Decision-Making Process From Signature Movement Styles: An Illustrative Study of Leaders

    Directory of Open Access Journals (Sweden)

    Brenda L. Connors

    2013-09-01

    Full Text Available There has been a surge of interest in examining the utility of methods for capturing individual differences in decision-making style. We illustrate the potential offered by Movement Pattern Analysis (MPA, an observational methodology that has been used in business and by the U.S. Department of Defense to record body movements that provide predictive insight into individual differences in decision-making motivations and actions. Twelve military officers participated in an intensive two-hour interview that permitted detailed and fine-grained observation and coding of signature movements by trained practitioners using MPA. Three months later, these subjects completed four hypothetical decision-making tasks in which the amount of information sought out before coming to a decision, as well as the time spent on the tasks, were under the partial control of the subject. A composite MPA indicator of how a person allocates decision-making actions and motivations to balance both Assertion (exertion of tangible movement effort on the environment to make something occur and Perspective (through movements that support shaping in the body to perceive and create a suitable environment for action was highly correlated with the total number of information draws and total response time – individuals high on Assertion reached for less information and had faster response times than those high on Perspective. Discussion focuses on the utility of using movement-based observational measures to capture individual differences in decision-making style and the implications for application in applied settings geared toward investigations of experienced leaders and world statesmen where individuality rules the day.

  12. 48 CFR 9904.408-60 - Illustrations.

    Science.gov (United States)

    2010-10-01

    ... Section 9904.408-60 Federal Acquisition Regulations System COST ACCOUNTING STANDARDS BOARD, OFFICE OF FEDERAL PROCUREMENT POLICY, OFFICE OF MANAGEMENT AND BUDGET PROCUREMENT PRACTICES AND COST ACCOUNTING STANDARDS COST ACCOUNTING STANDARDS 9904.408-60 Illustrations. (a) Company A's vacation plan provides that...

  13. 48 CFR 9904.403-60 - Illustrations.

    Science.gov (United States)

    2010-10-01

    ... Section 9904.403-60 Federal Acquisition Regulations System COST ACCOUNTING STANDARDS BOARD, OFFICE OF FEDERAL PROCUREMENT POLICY, OFFICE OF MANAGEMENT AND BUDGET PROCUREMENT PRACTICES AND COST ACCOUNTING STANDARDS COST ACCOUNTING STANDARDS 9904.403-60 Illustrations. (a) The following table lists some typical...

  14. 48 CFR 9904.407-60 - Illustrations.

    Science.gov (United States)

    2010-10-01

    ... Section 9904.407-60 Federal Acquisition Regulations System COST ACCOUNTING STANDARDS BOARD, OFFICE OF FEDERAL PROCUREMENT POLICY, OFFICE OF MANAGEMENT AND BUDGET PROCUREMENT PRACTICES AND COST ACCOUNTING STANDARDS COST ACCOUNTING STANDARDS 9904.407-60 Illustrations. (a) Contractor A's written practice is to set...

  15. 48 CFR 9904.410-60 - Illustrations.

    Science.gov (United States)

    2010-10-01

    ... Section 9904.410-60 Federal Acquisition Regulations System COST ACCOUNTING STANDARDS BOARD, OFFICE OF FEDERAL PROCUREMENT POLICY, OFFICE OF MANAGEMENT AND BUDGET PROCUREMENT PRACTICES AND COST ACCOUNTING STANDARDS COST ACCOUNTING STANDARDS 9904.410-60 Illustrations. (a) Business Unit A has been including the...

  16. Device of capturing for radioactive corrosion products

    International Nuclear Information System (INIS)

    Ohara, Atsushi; Fukushima, Kimichika.

    1984-01-01

    Purpose: To increase the area of contact between the capturing materials for the radioactive corrosion products contained in the coolants and the coolants by producing stirred turbulent flows in the coolant flow channel of LMFBR type reactors. Constitution: Constituent materials for the nuclear fuel elements or the reactor core structures are activated under the neutron irradiation, corroded and transferred into the coolants. While capturing devices made of pure metal nickel are used for the elimination of the corrosion products, since the coolants form laminar flows due to the viscosity thereof near the surface of the capturing materials, the probability that the corrosion products in the coolants flowing through the middle portion of the channel contact the capturing materials is reduced. In this invention, rotating rolls and flow channels in which the balls are rotated are disposed at the upstream of the capturing device to forcively disturb the flow of the liquid sodium, whereby the radioactive corrosion products can effectively be captured. (Kamimura, M.)

  17. Packet Capture Solutions: PcapDB Benchmark for High-Bandwidth Capture, Storage, and Searching

    Energy Technology Data Exchange (ETDEWEB)

    Steinfadt, Shannon Irene [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ferrell, Paul Steven [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-21

    PcapDB stands alone when looking at the overall field of competitors, from the cost-effective COTS hardware, to the efficient utilization of disk space that enables a longer packet history. A scalable, 100GbE-enabled system that indexes every packet and indexes flow data without complicated load-balancing requirements. The Transport Layer search and indexing approach led to patent-pending flow indexing technology, providing a specialized database system specifically optimized around providing fast flow searches. While there are a plethora of options in network packet capture, there are very few that are able to effectively manage capture rates of more than 10 Gb/s, distributed capture and querying, and a responsive user interface. By far, the primary competitor in the market place is Endace and DeepSee; in addition to meeting the technical requirements we set out in this document, they provide technical support and a fully 'appliance like' system. In terms of cost, however, our experience has been that the yearly maintenance charges alone outstrip the entire hardware cost of solutions like PcapDB. Investment in cyber security research and development is a large part of what has enabled us to build the base of knowlegable workers needed to defend government resources in the rapidly evolving cyber security landscape. We believe projects like Bro, WireCap, and Farm do more than just fill temporary gaps in our capabilities. They give allow us to build the firm foundation needed to tackle the next generation of cyber challenges. PcapDB was built with loftier ambitions than simply solving the packet capture of a single lab site, but instead to provide a robust, scaleable packet capture solution to the DOE complex and beyond.

  18. Measurements of neutron capture cross sections

    International Nuclear Information System (INIS)

    Nakajima, Yutaka

    1984-01-01

    A review of measurement techniques for the neutron capture cross sections is presented. Sell transmission method, activation method, and prompt gamma-ray detection method are described using examples of capture cross section measurements. The capture cross section of 238 U measured by three different prompt gamma-ray detection methods (large liquid scintillator, Moxon-Rae detector, and pulse height weighting method) are compared and their discrepancies are resolved. A method how to derive the covariance is described. (author)

  19. The Role of Relational Information in Contingent Capture

    Science.gov (United States)

    Becker, Stefanie I.; Folk, Charles L.; Remington, Roger W.

    2010-01-01

    On the contingent capture account, top-down attentional control settings restrict involuntary attentional capture to items that match the features of the search target. Attention capture is involuntary, but contingent on goals and intentions. The observation that only target-similar items can capture attention has usually been taken to show that…

  20. Comparison of Electronic Data Capture (EDC) with the Standard Data Capture Method for Clinical Trial Data

    Science.gov (United States)

    Walther, Brigitte; Hossin, Safayet; Townend, John; Abernethy, Neil; Parker, David; Jeffries, David

    2011-01-01

    Background Traditionally, clinical research studies rely on collecting data with case report forms, which are subsequently entered into a database to create electronic records. Although well established, this method is time-consuming and error-prone. This study compares four electronic data capture (EDC) methods with the conventional approach with respect to duration of data capture and accuracy. It was performed in a West African setting, where clinical trials involve data collection from urban, rural and often remote locations. Methodology/Principal Findings Three types of commonly available EDC tools were assessed in face-to-face interviews; netbook, PDA, and tablet PC. EDC performance during telephone interviews via mobile phone was evaluated as a fourth method. The Graeco Latin square study design allowed comparison of all four methods to standard paper-based recording followed by data double entry while controlling simultaneously for possible confounding factors such as interview order, interviewer and interviewee. Over a study period of three weeks the error rates decreased considerably for all EDC methods. In the last week of the study the data accuracy for the netbook (5.1%, CI95%: 3.5–7.2%) and the tablet PC (5.2%, CI95%: 3.7–7.4%) was not significantly different from the accuracy of the conventional paper-based method (3.6%, CI95%: 2.2–5.5%), but error rates for the PDA (7.9%, CI95%: 6.0–10.5%) and telephone (6.3%, CI95% 4.6–8.6%) remained significantly higher. While EDC-interviews take slightly longer, data become readily available after download, making EDC more time effective. Free text and date fields were associated with higher error rates than numerical, single select and skip fields. Conclusions EDC solutions have the potential to produce similar data accuracy compared to paper-based methods. Given the considerable reduction in the time from data collection to database lock, EDC holds the promise to reduce research-associated costs

  1. Comparison of electronic data capture (EDC with the standard data capture method for clinical trial data.

    Directory of Open Access Journals (Sweden)

    Brigitte Walther

    Full Text Available BACKGROUND: Traditionally, clinical research studies rely on collecting data with case report forms, which are subsequently entered into a database to create electronic records. Although well established, this method is time-consuming and error-prone. This study compares four electronic data capture (EDC methods with the conventional approach with respect to duration of data capture and accuracy. It was performed in a West African setting, where clinical trials involve data collection from urban, rural and often remote locations. METHODOLOGY/PRINCIPAL FINDINGS: Three types of commonly available EDC tools were assessed in face-to-face interviews; netbook, PDA, and tablet PC. EDC performance during telephone interviews via mobile phone was evaluated as a fourth method. The Graeco Latin square study design allowed comparison of all four methods to standard paper-based recording followed by data double entry while controlling simultaneously for possible confounding factors such as interview order, interviewer and interviewee. Over a study period of three weeks the error rates decreased considerably for all EDC methods. In the last week of the study the data accuracy for the netbook (5.1%, CI95%: 3.5-7.2% and the tablet PC (5.2%, CI95%: 3.7-7.4% was not significantly different from the accuracy of the conventional paper-based method (3.6%, CI95%: 2.2-5.5%, but error rates for the PDA (7.9%, CI95%: 6.0-10.5% and telephone (6.3%, CI95% 4.6-8.6% remained significantly higher. While EDC-interviews take slightly longer, data become readily available after download, making EDC more time effective. Free text and date fields were associated with higher error rates than numerical, single select and skip fields. CONCLUSIONS: EDC solutions have the potential to produce similar data accuracy compared to paper-based methods. Given the considerable reduction in the time from data collection to database lock, EDC holds the promise to reduce research

  2. Calibrating a numerical model's morphology using high-resolution spatial and temporal datasets from multithread channel flume experiments.

    Science.gov (United States)

    Javernick, L.; Bertoldi, W.; Redolfi, M.

    2017-12-01

    Accessing or acquiring high quality, low-cost topographic data has never been easier due to recent developments of the photogrammetric techniques of Structure-from-Motion (SfM). Researchers can acquire the necessary SfM imagery with various platforms, with the ability to capture millimetre resolution and accuracy, or large-scale areas with the help of unmanned platforms. Such datasets in combination with numerical modelling have opened up new opportunities to study river environments physical and ecological relationships. While numerical models overall predictive accuracy is most influenced by topography, proper model calibration requires hydraulic data and morphological data; however, rich hydraulic and morphological datasets remain scarce. This lack in field and laboratory data has limited model advancement through the inability to properly calibrate, assess sensitivity, and validate the models performance. However, new time-lapse imagery techniques have shown success in identifying instantaneous sediment transport in flume experiments and their ability to improve hydraulic model calibration. With new capabilities to capture high resolution spatial and temporal datasets of flume experiments, there is a need to further assess model performance. To address this demand, this research used braided river flume experiments and captured time-lapse observed sediment transport and repeat SfM elevation surveys to provide unprecedented spatial and temporal datasets. Through newly created metrics that quantified observed and modeled activation, deactivation, and bank erosion rates, the numerical model Delft3d was calibrated. This increased temporal data of both high-resolution time series and long-term temporal coverage provided significantly improved calibration routines that refined calibration parameterization. Model results show that there is a trade-off between achieving quantitative statistical and qualitative morphological representations. Specifically, statistical

  3. Atlas of Illustrative Cases of Tattoo Complications.

    Science.gov (United States)

    Serup, Jørgen

    2017-01-01

    Tattoos, and tattoo complications as well, are colorful and visually flashy. A clinical outlook provides important clues to diagnosis by pattern recognition. This atlas,which is a report of 79 case illustrations, is made as a practical tool and vade mecum for the clinician. The atlas can be used in the office and as a bedside tool. It includes characteristic photos, and each case is accompanied with a brief medical history, a comment with learning points, the final diagnosis, and a review of therapeutic options. This spectrum of cases illustrates the different diagnostic entities according to the newly proposed Bispebjerg University Hospital ('Tattoo Clinic') diagnostic system of tattoo complications, a system reported to the 11th revision of the WHO disease classification system. Cases include allergies predominantly seen in red tattoos manifesting the characteristic patterns of plaque elevation, excessive hyperkeratosis, ulcerating reactions, urticaria, and generalized skin rash. Each type of reaction has typical clues to diagnosis and a typical disease course. 'Cross-sensitivity' allergic reactions in old tattoos of the same color as the trigger tattoo are also illustrated. Reactions in black tattoos are dominated by a pattern with papulonodular reactions, which are nonallergic anddue to pigment agglomeration in the skin. Reactions may be granulomatous and a marker of systemic sarcoidosis, sometimes associated with a general outbreak in the skin in black tattoos, e.g. 'rush phenomenon'. Bacterial infections are also illustrated. The technical hazards of tattooing and sequels as well as unwanted effects of tattoo removal by lasers are shown along with severe scarring following tattoo removal by caustics. This atlas is a tutorial in modern medical and surgical treatments of tattoo complications. © 2017 S. Karger AG, Basel.

  4. Numerical Investigation of Transitional Flow over a Backward Facing Step Using a Low Reynolds Number k-ε Model

    DEFF Research Database (Denmark)

    Skovgaard, M.; Nielsen, Peter V.

    In this paper it is investigated if it is possible to simulate and capture some of the low Reynolds number effects numerically using time averaged momentum equations and a low Reynolds number k-f model. The test case is the larninar to turbulent transitional flow over a backward facing step...

  5. Numerical solution of continuous-time DSGE models under Poisson uncertainty

    DEFF Research Database (Denmark)

    Posch, Olaf; Trimborn, Timo

    We propose a simple and powerful method for determining the transition process in continuous-time DSGE models under Poisson uncertainty numerically. The idea is to transform the system of stochastic differential equations into a system of functional differential equations of the retarded type. We...... classes of models. We illustrate the algorithm simulating both the stochastic neoclassical growth model and the Lucas model under Poisson uncertainty which is motivated by the Barro-Rietz rare disaster hypothesis. We find that, even for non-linear policy functions, the maximum (absolute) error is very...

  6. A case for the introduction of numerical fiscal rules in the Serbian Constitution

    Directory of Open Access Journals (Sweden)

    Begović Boris

    2017-01-01

    Full Text Available The recommendation of numerical fiscal rules in Serbia, presented in this paper, is based on the inherent bias of fiscal policy towards expenditure, and consequently continuous fiscal deficit and excessive sovereign debt. It is recommended that simple and straightforward numeric fiscal rules should be introduced into the Serbian Constitution. There should be two cumulative numerical fiscal rules, the first regarding the ceiling on sovereign debt and the second regarding the ceiling on net new borrowing. Neither of the rules may be violated. The ceiling on the debt level should be prescribed by the Constitution. The ceiling on new net borrowing should depend on the distance of the sovereign debt from the debt ceiling. An illustrative example is provided, with a debt ceiling of 60%. However, the Fiscal Council should specify a specific sovereign debt ceiling as part of the proposed constitutional amendment.

  7. Simplified fuel cycle tritium inventory model for systems studies -- An illustrative example with an optimized cryopump exhaust system

    International Nuclear Information System (INIS)

    Kuan, W.; Ho, S.K.

    1995-01-01

    It is desirable to incorporate safety constraints due to fuel cycle tritium inventories into tokamak reactor design optimization. An optimal scenario to minimize tritium inventories without much degradation of plasma performance can be defined for each tritium processing component. In this work, the computer code TRUFFLES is used exclusively to obtain numerical data for a simplified model to be used for systems studies. As an illustration, the cryopump plasma exhaust subsystem is examined in detail for optimization purposes. This optimization procedure will then be used to further reduce its window of operation and provide constraints on the data used for the simplified tritium inventory model

  8. SENR /NRPy + : Numerical relativity in singular curvilinear coordinate systems

    Science.gov (United States)

    Ruchlin, Ian; Etienne, Zachariah B.; Baumgarte, Thomas W.

    2018-03-01

    We report on a new open-source, user-friendly numerical relativity code package called SENR /NRPy + . Our code extends previous implementations of the BSSN reference-metric formulation to a much broader class of curvilinear coordinate systems, making it ideally suited to modeling physical configurations with approximate or exact symmetries. In the context of modeling black hole dynamics, it is orders of magnitude more efficient than other widely used open-source numerical relativity codes. NRPy + provides a Python-based interface in which equations are written in natural tensorial form and output at arbitrary finite difference order as highly efficient C code, putting complex tensorial equations at the scientist's fingertips without the need for an expensive software license. SENR provides the algorithmic framework that combines the C codes generated by NRPy + into a functioning numerical relativity code. We validate against two other established, state-of-the-art codes, and achieve excellent agreement. For the first time—in the context of moving puncture black hole evolutions—we demonstrate nearly exponential convergence of constraint violation and gravitational waveform errors to zero as the order of spatial finite difference derivatives is increased, while fixing the numerical grids at moderate resolution in a singular coordinate system. Such behavior outside the horizons is remarkable, as numerical errors do not converge to zero near punctures, and all points along the polar axis are coordinate singularities. The formulation addresses such coordinate singularities via cell-centered grids and a simple change of basis that analytically regularizes tensor components with respect to the coordinates. Future plans include extending this formulation to allow dynamical coordinate grids and bispherical-like distribution of points to efficiently capture orbiting compact binary dynamics.

  9. Towards numerical simulations of supersonic liquid jets using ghost fluid method

    International Nuclear Information System (INIS)

    Majidi, Sahand; Afshari, Asghar

    2015-01-01

    Highlights: • A ghost fluid method based solver is developed for numerical simulation of compressible multiphase flows. • The performance of the numerical tool is validated via several benchmark problems. • Emergence of supersonic liquid jets in quiescent gaseous environment is simulated using ghost fluid method for the first time. • Bow-shock formation ahead of the liquid jet is clearly observed in the obtained numerical results. • Radiation of mach waves from the phase-interface witnessed experimentally is evidently captured in our numerical simulations. - Abstract: A computational tool based on the ghost fluid method (GFM) is developed to study supersonic liquid jets involving strong shocks and contact discontinuities with high density ratios. The solver utilizes constrained reinitialization method and is capable of switching between the exact and approximate Riemann solvers to increase the robustness. The numerical methodology is validated through several benchmark test problems; these include one-dimensional multiphase shock tube problem, shock–bubble interaction, air cavity collapse in water, and underwater-explosion. A comparison between our results and numerical and experimental observations indicate that the developed solver performs well investigating these problems. The code is then used to simulate the emergence of a supersonic liquid jet into a quiescent gaseous medium, which is the very first time to be studied by a ghost fluid method. The results of simulations are in good agreement with the experimental investigations. Also some of the famous flow characteristics, like the propagation of pressure-waves from the liquid jet interface and dependence of the Mach cone structure on the inlet Mach number, are reproduced numerically. The numerical simulations conducted here suggest that the ghost fluid method is an affordable and reliable scheme to study complicated interfacial evolutions in complex multiphase systems such as supersonic liquid

  10. Non-Markovian dynamics of quantum systems: decay rate, capture and pure states

    International Nuclear Information System (INIS)

    Kanokov, Z.; Palchikov, Yu.V.; Antonenko, N.V.; Adamian, G.G.; Kanokov, Z.; Adamian, G.G.; Scheid, W.

    2004-01-01

    Full text: With the exact numerical solution of the equation for the reduced density matrix we found a minor role of the time dependence of the friction and diffusion coefficients in the escape rate from a potential well [1]. Since the used friction and diffusion coefficients were self- consistently under certain approximations derived, they preserve the positivity of the density matrix at any time. The mixed diffusion coefficient leads to a decrease of the escape rate. Since the used value of quantum diffusion coefficient in momentum is larger than the one following from a 'classic' treatment, the obtained escape rate is close to the rate calculated with the 'classic' set of diffusion coefficients. If the regime of motion is close to the under damped case or the temperature is small, the quasi-stationary escape rate can increase with friction. This is explained by the larger role of the increasing diffusion in the decay process. The agreement of the escape rate obtained with the analytical expressions in comparison to numerically calculated data depends on the characteristics of the considered system. The agreement is better in the overdamped regime. However, for any regime the deviations are not larger than in the case of the classical Kramers formula. Therefore, the analytical expressions can be applied in a large range of parameters for the potential and diffusion coefficients. We demonstrated that the uncertainty function is related to the linear entropy. The diffusion coefficients supplying the purity of states were elaborated for the non-Markovian dynamics. The obtained dependences of the capture probability on the friction proves that the quantum nature of this process should be taken into consideration when one calculates the capture cross section in nucleus-nucleus collisions

  11. Attentional capture by masked colour singletons.

    Science.gov (United States)

    Ansorge, Ulrich; Horstmann, Gernot; Worschech, Franziska

    2010-09-15

    We tested under which conditions a colour singleton of which an observer is unaware captures attention. To prevent visual awareness of the colour singleton, we used backward masking. We find that a masked colour singleton cue captures attention if it matches the observer's goal to search for target colours but not if it is task-irrelevant. This is also reflected in event-related potentials to the visible target: the masked goal-matching cue elicits an attentional potential (N2pc) in a target search task. By contrast, a non-matching but equally strong masked colour singleton cue failed to elicit a capture effect and an N2pc. Results are discussed with regard to currently pertaining conceptions of attentional capture by colour singletons. Copyright 2010 Elsevier Ltd. All rights reserved.

  12. The seismic analyzer: interpreting and illustrating 2D seismic data.

    Science.gov (United States)

    Patel, Daniel; Giertsen, Christopher; Thurmond, John; Gjelberg, John; Gröller, M Eduard

    2008-01-01

    We present a toolbox for quickly interpreting and illustrating 2D slices of seismic volumetric reflection data. Searching for oil and gas involves creating a structural overview of seismic reflection data to identify hydrocarbon reservoirs. We improve the search of seismic structures by precalculating the horizon structures of the seismic data prior to interpretation. We improve the annotation of seismic structures by applying novel illustrative rendering algorithms tailored to seismic data, such as deformed texturing and line and texture transfer functions. The illustrative rendering results in multi-attribute and scale invariant visualizations where features are represented clearly in both highly zoomed in and zoomed out views. Thumbnail views in combination with interactive appearance control allows for a quick overview of the data before detailed interpretation takes place. These techniques help reduce the work of seismic illustrators and interpreters.

  13. Numerical Simulation of One-Dimensional Fractional Nonsteady Heat Transfer Model Based on the Second Kind Chebyshev Wavelet

    Directory of Open Access Journals (Sweden)

    Fuqiang Zhao

    2017-01-01

    Full Text Available In the current study, a numerical technique for solving one-dimensional fractional nonsteady heat transfer model is presented. We construct the second kind Chebyshev wavelet and then derive the operational matrix of fractional-order integration. The operational matrix of fractional-order integration is utilized to reduce the original problem to a system of linear algebraic equations, and then the numerical solutions obtained by our method are compared with those obtained by CAS wavelet method. Lastly, illustrated examples are included to demonstrate the validity and applicability of the technique.

  14. Numerical Approximations to the Solution of Ray Tracing through the Crystalline Lens

    International Nuclear Information System (INIS)

    Yildirim, A.; Gökdoğan, A.; Merdan, M.; Lakshminarayanan, V.

    2012-01-01

    An approximate analytical solution in the form of a rapidly convergent series for tracing light rays through an inhomogeneous graded index medium is developed, using the multi-step differential transform method based on the classical differential transformation method. Numerical results are compared to those obtained by the fourth-order Runge—Kutta method to illustrate the precision and effectiveness of the proposed method. Results are given in explicit and graphical forms. (fundamental areas of phenomenology(including applications))

  15. Quantum tomography for collider physics. Illustrations with lepton-pair production

    Energy Technology Data Exchange (ETDEWEB)

    Martens, John C.; Ralston, John P.; Takaki, J.D.T. [The University of Kansas, Department of Physics and Astronomy, Lawrence, KS (United States)

    2018-01-15

    Quantum tomography is a method to experimentally extract all that is observable about a quantum mechanical system. We introduce quantum tomography to collider physics with the illustration of the angular distribution of lepton pairs. The tomographic method bypasses much of the field-theoretic formalism to concentrate on what can be observed with experimental data. We provide a practical, experimentally driven guide to model-independent analysis using density matrices at every step. Comparison with traditional methods of analyzing angular correlations of inclusive reactions finds many advantages in the tomographic method, which include manifest Lorentz covariance, direct incorporation of positivity constraints, exhaustively complete polarization information, and new invariants free from frame conventions. For example, experimental data can determine the entanglement entropy of the production process. We give reproducible numerical examples and provide a supplemental standalone computer code that implements the procedure. We also highlight a property of complex positivity that guarantees in a least-squares type fit that a local minimum of a χ{sup 2} statistic will be a global minimum: There are no isolated local minima. This property with an automated implementation of positivity promises to mitigate issues relating to multiple minima and convention dependence that have been problematic in previous work on angular distributions. (orig.)

  16. Quantum tomography for collider physics: illustrations with lepton-pair production

    Science.gov (United States)

    Martens, John C.; Ralston, John P.; Takaki, J. D. Tapia

    2018-01-01

    Quantum tomography is a method to experimentally extract all that is observable about a quantum mechanical system. We introduce quantum tomography to collider physics with the illustration of the angular distribution of lepton pairs. The tomographic method bypasses much of the field-theoretic formalism to concentrate on what can be observed with experimental data. We provide a practical, experimentally driven guide to model-independent analysis using density matrices at every step. Comparison with traditional methods of analyzing angular correlations of inclusive reactions finds many advantages in the tomographic method, which include manifest Lorentz covariance, direct incorporation of positivity constraints, exhaustively complete polarization information, and new invariants free from frame conventions. For example, experimental data can determine the entanglement entropy of the production process. We give reproducible numerical examples and provide a supplemental standalone computer code that implements the procedure. We also highlight a property of complex positivity that guarantees in a least-squares type fit that a local minimum of a χ 2 statistic will be a global minimum: There are no isolated local minima. This property with an automated implementation of positivity promises to mitigate issues relating to multiple minima and convention dependence that have been problematic in previous work on angular distributions.

  17. Constant-parameter capture-recapture models

    Science.gov (United States)

    Brownie, C.; Hines, J.E.; Nichols, J.D.

    1986-01-01

    Jolly (1982, Biometrics 38, 301-321) presented modifications of the Jolly-Seber model for capture-recapture data, which assume constant survival and/or capture rates. Where appropriate, because of the reduced number of parameters, these models lead to more efficient estimators than the Jolly-Seber model. The tests to compare models given by Jolly do not make complete use of the data, and we present here the appropriate modifications, and also indicate how to carry out goodness-of-fit tests which utilize individual capture history information. We also describe analogous models for the case where young and adult animals are tagged. The availability of computer programs to perform the analysis is noted, and examples are given using output from these programs.

  18. Numerical analysis of regular waves over an onshore oscillating water column

    Energy Technology Data Exchange (ETDEWEB)

    Davyt, D.P.; Teixeira, P.R.F. [Universidade Federal do Rio Grande (FURG), RS (Brazil)], E-mail: pauloteixeira@furg.br; Ramalhais, R. [Universidade Nova de Lisboa, Caparica (Portugal). Fac. de Ciencias e Tecnologia; Didier, E. [Laboratorio Nacional de Engenharia Civil, Lisboa (Portugal)], E-mail: edidier@lnec.pt

    2010-07-01

    The potential of wave energy along coastal areas is a particularly attractive option in regions of high latitude, such as the coasts of northern Europe, North America, New Zealand, Chile and Argentina where high densities of annual average wave energy are found (typically between 40 and 100 kW/m of wave front). Power estimated in the south of Brazil is 30kW/m, creating a possible alternative of source energy in the region. There are many types and designs of equipment to capture energy from waves under analysis, such as the oscillating water column type (OWC) which has been one of the first to be developed and installed at sea. Despite being one of the most analyzed wave energy converter devices, there are few case studies using numerical simulation. In this context, the numerical analysis of regular waves over an onshore OWC is the main objective of this paper. The numerical models FLUINCO and FLUENT are used for achieving this goal. The FLUINCO model is based on RANS equations which are discretized using the two-step semi-implicit Taylor-Galerkin method. An arbitrary Lagrangian Eulerian formulation is used to enable the solution of problems involving free surface movements. The FLUENT code (version 6.3.26) is based on the finite volume method to solve RANS equations. Volume of Fluid method (VOF) is used for modeling free surface flows. Time integration is achieved by a second order implicit scheme, momentum equations are discretized using MUSCL scheme and HRIC (High Resolution Interface Capturing) scheme is used for convective term of VOF transport equation. The case study consists of a 10.m deep channel with a 10 m wide chamber at its end. One meter high waves with different periods are simulated. Comparisons between FLUINCO and FLUENT results are presented. Free surface elevation inside the chamber; velocity distribution and streamlines; amplification factor (relation between wave height inside the chamber and incident wave height); phase angle (angular

  19. Developments in Characterizing Capture Zone Distributions in Island Growth

    Science.gov (United States)

    Einstein, T. L.; Pimpinelli, Alberto; GonzáLez, Diego Luis; Sathiyanarayanan, Rajesh

    2013-03-01

    The utility of using the distribution of capture zones (CZD) to characterize epitaxial growth continues to mount. For non-Poisson deposition (i.e. when island nucleation is not fully random) the areas of these Voronoi cells (proximity polygons) can be well described by the generalized Wigner distribution (GWD), particularly in the central region around the mean area. We discuss several recent applications to experimental systems, showing how this perspective leads to insights about the critical nucleus size. In contrast, several studies have shown that the GWD may not describe the numerical data from painstaking simulations in both tails. We discuss some refinements that have been proposed. Finally, we comment on applications to social phenomena such as area distributions of secondary administrative units (like counties) and of Voronoi cells around Metro stops. Work at UMD supported by NSF-MRSEC Grant DMR 05-20471 and NSF CHE 07-49949

  20. AMUC: Associated Motion capture User Categories.

    Science.gov (United States)

    Norman, Sally Jane; Lawson, Sian E M; Olivier, Patrick; Watson, Paul; Chan, Anita M-A; Dade-Robertson, Martyn; Dunphy, Paul; Green, Dave; Hiden, Hugo; Hook, Jonathan; Jackson, Daniel G

    2009-07-13

    The AMUC (Associated Motion capture User Categories) project consisted of building a prototype sketch retrieval client for exploring motion capture archives. High-dimensional datasets reflect the dynamic process of motion capture and comprise high-rate sampled data of a performer's joint angles; in response to multiple query criteria, these data can potentially yield different kinds of information. The AMUC prototype harnesses graphic input via an electronic tablet as a query mechanism, time and position signals obtained from the sketch being mapped to the properties of data streams stored in the motion capture repository. As well as proposing a pragmatic solution for exploring motion capture datasets, the project demonstrates the conceptual value of iterative prototyping in innovative interdisciplinary design. The AMUC team was composed of live performance practitioners and theorists conversant with a variety of movement techniques, bioengineers who recorded and processed motion data for integration into the retrieval tool, and computer scientists who designed and implemented the retrieval system and server architecture, scoped for Grid-based applications. Creative input on information system design and navigation, and digital image processing, underpinned implementation of the prototype, which has undergone preliminary trials with diverse users, allowing identification of rich potential development areas.

  1. Les Anglo-americanismes du "Petit Larousse Illustre 1979" (Anglo-Americanisms in the 1979 "Petit Larousse Illustre").

    Science.gov (United States)

    Trescases, Pierre

    1979-01-01

    Based on the 1979 edition of the "Petit Larousse Illustre," English or American loan words are evaluated as to their actual usage in modern French. It is concluded that anglo-americanisms have a greater impact on technical French than on everyday French. A list of 57 words that have become part of French usage is provided for pedagogical…

  2. Experimental and numerical study of water-filled vessel impacted by flat projectiles

    Science.gov (United States)

    Zhang, Wei; Ren, Peng; Huang, Wei; Gao, Yu Bo

    2014-05-01

    To understand the failure modes and impact resistance of double-layer plates separated by water, a flat-nosed projectile was accelerated by a two-stage light gas gun against a water-filled vessel which was placed in an air-filled tank. Targets consisted of a tank made of two flat 5A06 aluminum alloy plates held by a high strength steel frame. The penetration process was recorded by a digital high-speed camera. The same projectile-target system was also used to fire the targets placed directly in air for comparison. Parallel numerical tests were also carried out. The result indicated that experimental and numerical results were in good agreement. Numerical simulations were able to capture the main physical behavior. It was also found that the impact resistance of double layer plates separated by water was lager than that of the target plates in air. Tearing was the main failure models of the water-filled vessel targets which was different from that of the target plates in air where the shear plugging was in dominate.

  3. Measurement and numerical simulation of high intensity focused ultrasound field in water

    Science.gov (United States)

    Lee, Kang Il

    2017-11-01

    In the present study, the acoustic field of a high intensity focused ultrasound (HIFU) transducer in water was measured by using a commercially available needle hydrophone intended for HIFU use. To validate the results of hydrophone measurements, numerical simulations of HIFU fields were performed by integrating the axisymmetric Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation from the frequency-domain perspective with the help of a MATLAB-based software package developed for HIFU simulation. Quantitative values for the focal waveforms, the peak pressures, and the size of the focal spot were obtained in various regimes of linear, quasilinear, and nonlinear propagation up to the source pressure levels when the shock front was formed in the waveform. The numerical results with the HIFU simulator solving the KZK equation were compared with the experimental data and found to be in good agreement. This confirms that the numerical simulation based on the KZK equation is capable of capturing the nonlinear pressure field of therapeutic HIFU transducers well enough to make it suitable for HIFU treatment planning.

  4. Physiological reactions to capture in hibernating brown bears.

    Science.gov (United States)

    Evans, Alina L; Singh, Navinder J; Fuchs, Boris; Blanc, Stéphane; Friebe, Andrea; Laske, Timothy G; Frobert, Ole; Swenson, Jon E; Arnemo, Jon M

    2016-01-01

    Human disturbance can affect animal life history and even population dynamics. However, the consequences of these disturbances are difficult to measure. This is especially true for hibernating animals, which are highly vulnerable to disturbance, because hibernation is a process of major physiological changes, involving conservation of energy during a resource-depleted time of year. During the winters of 2011-15, we captured 15 subadult brown bears ( Ursus arctos ) and recorded their body temperatures ( n  = 11) and heart rates ( n = 10) before, during and after capture using biologgers. We estimated the time for body temperature and heart rate to normalize after the capture event. We then evaluated the effect of the captures on the pattern and depth of hibernation and the day of den emergence by comparing the body temperature of captured bears with that of undisturbed subadult bears ( n  = 11). Both body temperature and heart rate increased during capture and returned to hibernation levels after 15-20 days. We showed that bears required 2-3 weeks to return to hibernation levels after winter captures, suggesting high metabolic costs during this period. There were also indications that the winter captures resulted in delayed den emergence.

  5. A primer on stochastic epidemic models: Formulation, numerical simulation, and analysis

    Directory of Open Access Journals (Sweden)

    Linda J.S. Allen

    2017-05-01

    Full Text Available Some mathematical methods for formulation and numerical simulation of stochastic epidemic models are presented. Specifically, models are formulated for continuous-time Markov chains and stochastic differential equations. Some well-known examples are used for illustration such as an SIR epidemic model and a host-vector malaria model. Analytical methods for approximating the probability of a disease outbreak are also discussed. Keywords: Branching process, Continuous-time Markov chain, Minor outbreak, Stochastic differential equation, 2000 MSC: 60H10, 60J28, 92D30

  6. Some properties of band matrix and its application to the numerical solution one-dimensional Bratu's problem

    Directory of Open Access Journals (Sweden)

    Reza Jalilian

    2014-07-01

    Full Text Available ‎A Class of new methods based on a septic non-polynomial spline‎‎function for the numerical solution one-dimensional Bratu's problem‎are presented‎. ‎The local truncation errors and the methods of order‎‎2th‎, ‎4th‎, ‎6th‎, ‎8th‎, ‎10th‎, ‎and 12th‎, ‎are obtained‎. ‎The inverse of‎some band matrixes are obtained which are required in provingthe‎ convergence analysis of the presented method‎. ‎Associatedboundary‎ formulas are developed‎. ‎Convergence analysis of thesemethods is‎ discussed‎. ‎Numerical results are given to illustrate theefficiency‎ of methods‎.

  7. Variable High Order Multiblock Overlapping Grid Methods for Mixed Steady and Unsteady Multiscale Viscous Flows

    Science.gov (United States)

    Sjogreen, Bjoern; Yee, H. C.

    2007-01-01

    Flows containing steady or nearly steady strong shocks in parts of the flow field, and unsteady turbulence with shocklets on other parts of the flow field are difficult to capture accurately and efficiently employing the same numerical scheme even under the multiblock grid or adaptive grid refinement framework. On one hand, sixth-order or higher shock-capturing methods are appropriate for unsteady turbulence with shocklets. On the other hand, lower order shock-capturing methods are more effective for strong steady shocks in terms of convergence. In order to minimize the shortcomings of low order and high order shock-capturing schemes for the subject flows,a multi- block overlapping grid with different orders of accuracy on different blocks is proposed. Test cases to illustrate the performance of the new solver are included.

  8. Illustrative visualization of 3D city models

    Science.gov (United States)

    Doellner, Juergen; Buchholz, Henrik; Nienhaus, Marc; Kirsch, Florian

    2005-03-01

    This paper presents an illustrative visualization technique that provides expressive representations of large-scale 3D city models, inspired by the tradition of artistic and cartographic visualizations typically found in bird"s-eye view and panoramic maps. We define a collection of city model components and a real-time multi-pass rendering algorithm that achieves comprehensible, abstract 3D city model depictions based on edge enhancement, color-based and shadow-based depth cues, and procedural facade texturing. Illustrative visualization provides an effective visual interface to urban spatial information and associated thematic information complementing visual interfaces based on the Virtual Reality paradigm, offering a huge potential for graphics design. Primary application areas include city and landscape planning, cartoon worlds in computer games, and tourist information systems.

  9. Understanding Motion Capture for Computer Animation

    CERN Document Server

    Menache, Alberto

    2010-01-01

    The power of today's motion capture technology has taken animated characters and special effects to amazing new levels of reality. And with the release of blockbusters like Avatar and Tin-Tin, audiences continually expect more from each new release. To live up to these expectations, film and game makers, particularly technical animators and directors, need to be at the forefront of motion capture technology. In this extensively updated edition of Understanding Motion Capture for Computer Animation and Video Games, an industry insider explains the latest research developments in digital design

  10. Advances in variational and hemivariational inequalities theory, numerical analysis, and applications

    CERN Document Server

    Migórski, Stanisław; Sofonea, Mircea

    2015-01-01

    Highlighting recent advances in variational and hemivariational inequalities with an emphasis on theory, numerical analysis and applications, this volume serves as an indispensable resource to graduate students and researchers interested in the latest results from recognized scholars in this relatively young and rapidly-growing field. Particularly, readers will find that the volume’s results and analysis present valuable insights into the fields of pure and applied mathematics, as well as civil, aeronautical, and mechanical engineering. Researchers and students will find new results on well posedness to stationary and evolutionary inequalities and their rigorous proofs. In addition to results on modeling and abstract problems, the book contains new results on the numerical methods for variational and hemivariational inequalities. Finally, the applications presented illustrate the use of these results in the study of miscellaneous mathematical models which describe the contact between deformable bodies and a...

  11. Active Traffic Capture for Network Forensics

    Science.gov (United States)

    Slaviero, Marco; Granova, Anna; Olivier, Martin

    Network traffic capture is an integral part of network forensics, but current traffic capture techniques are typically passive in nature. Under heavy loads, it is possible for a sniffer to miss packets, which affects the quality of forensic evidence.

  12. An Eulerian method for computation of multimaterial impact with ENO shock-capturing and sharp interfaces

    CERN Document Server

    Udaykumar, H S; Belk, D M; Vanden, K J

    2003-01-01

    A technique is presented for the numerical simulation of high-speed multimaterial impact. Of particular interest is the interaction of solid impactors with targets. The computations are performed on a fixed Cartesian mesh by casting the equations governing material deformation in Eulerian conservation law form. The advantage of the Eulerian setting is the disconnection of the mesh from the boundary deformation allowing for large distortions of the interfaces. Eigenvalue analysis reveals that the system of equations is hyperbolic for the range of materials and impact velocities of interest. High-order accurate ENO shock-capturing schemes are used along with interface tracking techniques to evolve sharp immersed boundaries. The numerical technique is designed to tackle the following physical phenomena encountered during impact: (1) high velocities of impact leading to large deformations of the impactor as well as targets; (2) nonlinear wave-propagation and the development of shocks in the materials; (3) modelin...

  13. Learning hatching for pen-and-ink illustration of surfaces

    KAUST Repository

    Kalogerakis, Evangelos

    2012-01-01

    This article presents an algorithm for learning hatching styles from line drawings. An artist draws a single hatching illustration of a 3D object. Her strokes are analyzed to extract the following per-pixel properties: hatching level (hatching, cross-hatching, or no strokes), stroke orientation, spacing, intensity, length, and thickness. A mapping is learned from input geometric, contextual, and shading features of the 3D object to these hatching properties, using classification, regression, and clustering techniques. Then, a new illustration can be generated in the artist\\'s style, as follows. First, given a new view of a 3D object, the learned mapping is applied to synthesize target stroke properties for each pixel. A new illustration is then generated by synthesizing hatching strokes according to the target properties. © 2012 ACM.

  14. A fully relativistic approach for calculating atomic data for highly charged ions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hong Lin [Los Alamos National Laboratory; Fontes, Christopher J [Los Alamos National Laboratory; Sampson, Douglas H [PENNSYLVANIA STATE UNIV

    2009-01-01

    We present a review of our fully relativistic approach to calculating atomic data for highly charged ions, highlighting a research effort that spans twenty years. Detailed discussions of both theoretical and numerical techniques are provided. Our basic approach is expected to provide accurate results for ions that range from approximately half ionized to fully stripped. Options for improving the accuracy and range of validity of this approach are also discussed. In developing numerical methods for calculating data within this framework, considerable emphasis is placed on techniques that are robust and efficient. A variety of fundamental processes are considered including: photoexcitation, electron-impact excitation, electron-impact ionization, autoionization, electron capture, photoionization and photorecombination. Resonance contributions to a variety of these processes are also considered, including discussions of autoionization, electron capture and dielectronic recombination. Ample numerical examples are provided in order to illustrate the approach and to demonstrate its usefulness in providing data for large-scale plasma modeling.

  15. Alignment in double capture processes

    International Nuclear Information System (INIS)

    Moretto-Capelle, P.; Benhenni, M.; Bordenave-Montesquieu, A.; Benoit-Cattin, P.; Gleizes, A.

    1993-01-01

    The electron spectra emitted when a double capture occurs in N 7+ +He and Ne 8+ +He systems at 10 qkeV collisional energy, allow us to determine the angular distributions of the 3 ell 3 ell ' lines through a special spectra fitting procedure which includes interferences between neighbouring states. It is found that the doubly excited states populated in double capture processes are generally aligned

  16. Sequence capture by hybridization to explore modern and ancient genomic diversity in model and nonmodel organisms.

    Science.gov (United States)

    Gasc, Cyrielle; Peyretaillade, Eric; Peyret, Pierre

    2016-06-02

    The recent expansion of next-generation sequencing has significantly improved biological research. Nevertheless, deep exploration of genomes or metagenomic samples remains difficult because of the sequencing depth and the associated costs required. Therefore, different partitioning strategies have been developed to sequence informative subsets of studied genomes. Among these strategies, hybridization capture has proven to be an innovative and efficient tool for targeting and enriching specific biomarkers in complex DNA mixtures. It has been successfully applied in numerous areas of biology, such as exome resequencing for the identification of mutations underlying Mendelian or complex diseases and cancers, and its usefulness has been demonstrated in the agronomic field through the linking of genetic variants to agricultural phenotypic traits of interest. Moreover, hybridization capture has provided access to underexplored, but relevant fractions of genomes through its ability to enrich defined targets and their flanking regions. Finally, on the basis of restricted genomic information, this method has also allowed the expansion of knowledge of nonreference species and ancient genomes and provided a better understanding of metagenomic samples. In this review, we present the major advances and discoveries permitted by hybridization capture and highlight the potency of this approach in all areas of biology. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  17. Unsteady numerical simulation of the flow in the U9 Kaplan turbine model

    International Nuclear Information System (INIS)

    Javadi, Ardalan; Nilsson, Håkan

    2014-01-01

    The Reynolds-averaged Navier-Stokes equations with the RNG k-ε turbulence model closure are utilized to simulate the unsteady turbulent flow throughout the whole flow passage of the U9 Kaplan turbine model. The U9 Kaplan turbine model comprises 20 stationary guide vanes and 6 rotating blades (696.3 RPM), working at best efficiency load (0.71 m 3 /s). The computations are conducted using a general finite volume method, using the OpenFOAM CFD code. A dynamic mesh is used together with a sliding GGI interface to include the effect of the rotating runner. The clearance is included in the guide vane. The hub and tip clearances are also included in the runner. An analysis is conducted of the unsteady behavior of the flow field, the pressure fluctuation in the draft tube, and the coherent structures of the flow. The tangential and axial velocity distributions at three sections in the draft tube are compared against LDV measurements. The numerical result is in reasonable agreement with the experimental data, and the important flow physics close to the hub in the draft tube is captured. The hub and tip vortices and an on-axis forced vortex are captured. The numerical results show that the frequency of the forced vortex in 1/5 of the runner rotation

  18. Unsteady numerical simulation of the flow in the U9 Kaplan turbine model

    Science.gov (United States)

    Javadi, Ardalan; Nilsson, Håkan

    2014-03-01

    The Reynolds-averaged Navier-Stokes equations with the RNG k-ε turbulence model closure are utilized to simulate the unsteady turbulent flow throughout the whole flow passage of the U9 Kaplan turbine model. The U9 Kaplan turbine model comprises 20 stationary guide vanes and 6 rotating blades (696.3 RPM), working at best efficiency load (0.71 m3/s). The computations are conducted using a general finite volume method, using the OpenFOAM CFD code. A dynamic mesh is used together with a sliding GGI interface to include the effect of the rotating runner. The clearance is included in the guide vane. The hub and tip clearances are also included in the runner. An analysis is conducted of the unsteady behavior of the flow field, the pressure fluctuation in the draft tube, and the coherent structures of the flow. The tangential and axial velocity distributions at three sections in the draft tube are compared against LDV measurements. The numerical result is in reasonable agreement with the experimental data, and the important flow physics close to the hub in the draft tube is captured. The hub and tip vortices and an on-axis forced vortex are captured. The numerical results show that the frequency of the forced vortex in 1/5 of the runner rotation.

  19. System and process for capture of H.sub.2S from gaseous process streams and process for regeneration of the capture agent

    Science.gov (United States)

    Heldenbrant, David J; Koech, Phillip K; Rainbolt, James E; Bearden, Mark D; Zheng, Feng

    2014-02-18

    A system and process are disclosed for selective removal and recovery of H.sub.2S from a gaseous volume, e.g., from natural gas. Anhydrous organic, sorbents chemically capture H.sub.2S gas to form hydrosulfide salts. Regeneration of the capture solvent involves addition of an anti-solvent that releases the captured H.sub.2S gas from the capture sorbent. The capture sorbent and anti-solvent are reactivated for reuse, e.g., by simple distillation.

  20. Sub-barrier capture with quantum diffusion approach

    Directory of Open Access Journals (Sweden)

    Scheid W.

    2011-10-01

    Full Text Available With the quantum diffusion approach the behavior of capture cross sections and mean-square angular momenta of captured systems are revealed in the reactions with deformed and spherical nuclei at sub-barrier energies. With decreasing bombarding energy under the barrier the external turning point of the nucleus-nucleus potential leaves the region of short-range nuclear interaction and action of friction. Because of this change of the regime of interaction, an unexpected enhancement of the capture cross section is found at bombarding energies far below the Coulomb barrier. This effect is shown its worth in the dependence of mean-square angular momentum on the bombarding energy. From the comparison of calculated capture cross sections and experimental capture or fusion cross sections the importance of quasifission near the entrance channel is demonstrated for the actinidebased reactions and reactions with medium-heavy nuclei at extreme sub-barrier energies.

  1. Illustrations as Adjuncts to Prose: A Text-Appropriate Processing Approach.

    Science.gov (United States)

    Waddill, Paula J.; And Others

    1988-01-01

    The effects of pictorial illustrations on memory for text were studied in 144 college students. Two experiments indicated that illustrations serve a supplementary function; adjunct pictures alone, without special processing instructions, do not help learners encode information that is not normally encoded in the first place. (SLD)

  2. Mental Imagery, Text Illustrations, and Children's Story Comprehension and Recall.

    Science.gov (United States)

    Gambrell, Linda B.; Jawitz, Paula Brooks

    1993-01-01

    Investigates the effects of instructions to induce mental imagery and attend to text illustrations on fourth graders' reading comprehension and recall of narrative text. Finds that images and illustrations independently enhanced reading performance and that, in combination, these two strategies resulted in impressive increases in children's…

  3. A grieving process illustrated?

    Science.gov (United States)

    Hutchinson, Rory

    2018-03-01

    The sudden death of Pablo Picasso's closest friend Carlos Casagemas in 1901 came as a great shock to the young Picasso. From a young age, Picasso had ruminated on life and death; however, this was his first experience of bereavement. Following the death of Casagemas, Picasso's paintings can be seen as a diary of his grieving process and clearly illustrate the five stages of the grieving process as outlined by Kubler-Ross in ' On Death and Dying ' (1969). Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  4. Straussian Grounded-Theory Method: An Illustration

    Science.gov (United States)

    Thai, Mai Thi Thanh; Chong, Li Choy; Agrawal, Narendra M.

    2012-01-01

    This paper demonstrates the benefits and application of Straussian Grounded Theory method in conducting research in complex settings where parameters are poorly defined. It provides a detailed illustration on how this method can be used to build an internationalization theory. To be specific, this paper exposes readers to the behind-the-scene work…

  5. Prospects for carbon capture and sequestration technologies assuming their technological learning

    International Nuclear Information System (INIS)

    Riahi, Keywan; Rubin, Edward S.; Schrattenholzer, Leo

    2004-01-01

    This paper analyzes potentials of carbon capture and sequestration technologies (CCS) in a set of long-term energy-economic-environmental scenarios based on alternative assumptions for technological progress of CCS. In order to get a reasonable guide to future technological progress in managing CO 2 emissions, we review past experience in controlling sulfur dioxide emissions (SO 2 ) from power plants. By doing so, we quantify a 'learning curve' for CCS, which describes the relationship between the improvement of costs due to accumulation of experience in CCS construction. We incorporate the learning curve into the energy modeling framework MESSAGE-MACRO and develop greenhouse gas emissions scenarios of economic, demographic, and energy demand development, where alternative policy cases lead to the stabilization of atmospheric CO 2 concentrations at 550 parts per million by volume (ppmv) by the end of the 21st century. Due to the assumed technological learning, costs of the emissions reduction for CCS drop rapidly and in parallel with the massive introduction of CCS on the global scale. Compared to scenarios based on static cost assumptions for CCS, the contribution of carbon sequestration is about 50 percent higher in the case of learning resulting in cumulative sequestration of CO 2 ranging from 150 to 250 billion (10 9 ) tons carbon during the 21st century. The results illustrate that carbon capture and sequestration is one of the obvious priority candidates for long-term technology policies and enhanced R and D efforts to hedge against the risk associated with high environmental impacts of climate change

  6. Knowledge Capture and Acquisition Mechanisms at Kisii University

    Directory of Open Access Journals (Sweden)

    Nemwel Aming'a

    2015-07-01

    Full Text Available Knowledge management and knowledge assets have gained much prominence in recent years and are said to improve organizational performance. Knowledge capture and acquisition mechanisms enhance organizational memory and performance. However, knowledge capture and acquisition mechanisms in higher education institutions are not well known. The aim of this study was to investigate the knowledge capture and acquisition mechanisms at Kisii University. This was a case study in which data were collected through interviews and questionnaires. Purposive sampling was used to determine interview participants while questionnaire respondents were selected through stratified random sampling. Qualitative and quantitative data were analysed using SPSS® student version 14; it revealed that there were various knowledge capture and acquisition mechanisms at Kisii University. It was also established that the University encountered various challenges in knowledge capture and acquisition and lacked some essential knowledge capture and acquisition mechanisms. In this regard, this study proposed knowledge capture and acquisition guidelines that may be adopted by the University to enhance its organizational memory and performance.

  7. Robust numerical simulation of porosity evolution in chemical vapor infiltration III: three space dimension

    CERN Document Server

    Jin Shi

    2003-01-01

    Chemical vapor infiltration (CVI) process is an important technology to fabricate ceramic matrix composites (CMC's). In this paper, a three-dimension numerical model is presented to describe pore microstructure evolution during the CVI process. We extend the two-dimension model proposed in [S. Jin, X.L. Wang, T.L. Starr, J. Mater. Res. 14 (1999) 3829; S. Jin. X.L. Wang, T.L. Starr, X.F. Chen, J. Comp. Phys. 162 (2000) 467], where the fiber surface is modeled as an evolving interface, to the three space dimension. The 3D method keeps all the virtue of the 2D model: robust numerical capturing of topological changes of the interface such as the merging, and fast detection of the inaccessible pores. For models in the kinetic limit, where the moving speed of the interface is constant, some numerical examples are presented to show that this three-dimension model will effectively track the change of porosity, close-off time, location and shape of all pores.

  8. A volume-filtered formulation to capture particle-shock interactions in multiphase compressible flows

    Science.gov (United States)

    Shallcross, Gregory; Capecelatro, Jesse

    2017-11-01

    Compressible particle-laden flows are common in engineering systems. Applications include but are not limited to water injection in high-speed jet flows for noise suppression, rocket-plume surface interactions during planetary landing, and explosions during coal mining operations. Numerically, it is challenging to capture these interactions due to the wide range of length and time scales. Additionally, there are many forms of the multiphase compressible flow equations with volume fraction effects, some of which are conflicting in nature. The purpose of this presentation is to develop the capability to accurately capture particle-shock interactions in systems with a large number of particles from dense to dilute regimes. A thorough derivation of the volume filtered equations is presented. The volume filtered equations are then implemented in a high-order, energy-stable Eulerian-Lagrangian framework. We show this framework is capable of decoupling the fluid mesh from the particle size, enabling arbitrary particle size distributions in the presence of shocks. The proposed method is then assessed against particle-laden shock tube data. Quantities of interest include fluid-phase pressure profiles and particle spreading rates. The effect of collisions in 2D and 3D are also evaluated.

  9. Proton capture resonance studies

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, G.E. [North Carolina State University, Raleigh, North Carolina (United States) 27695]|[Triangle Universities Nuclear Laboratory, Durham, North Carolina (United States) 27708; Bilpuch, E.G. [Duke University, Durham, North Carolina (United States) 27708]|[Triangle Universities Nuclear Laboratory, Durham, North Carolina (United States) 27708; Bybee, C.R. [North Carolina State University, Raleigh, North Carolina (United States) 27695]|[Triangle Universities Nuclear Laboratory, Durham, North Carolina (United States) 27708; Cox, J.M.; Fittje, L.M. [Tennessee Technological University, Cookeville, Tennessee (United States) 38505]|[Triangle Universities Nuclear Laboratory, Durham, North Carolina (United States) 27708; Labonte, M.A.; Moore, E.F.; Shriner, J.D. [North Carolina State University, Raleigh, North Carolina (United States) 27695]|[Triangle Universities Nuclear Laboratory, Durham, North Carolina (United States) 27708; Shriner, J.F. Jr. [Tennessee Technological University, Cookeville, Tennessee (United States) 38505]|[Triangle Universities Nuclear Laboratory, Durham, North Carolina (United States) 27708; Vavrina, G.A. [North Carolina State University, Raleigh, North Carolina (United States) 27695]|[Triangle Universities Nuclear Laboratory, Durham, North Carolina (United States) 27708; Wallace, P.M. [Duke University, Durham, North Carolina (United States) 27708]|[Triangle Universities Nuclear Laboratory, Durham, North Carolina (United States) 27708

    1997-02-01

    The fluctuation properties of quantum systems now are used as a signature of quantum chaos. The analyses require data of extremely high quality. The {sup 29}Si(p,{gamma}) reaction is being used to establish a complete level scheme of {sup 30}P to study chaos and isospin breaking in this nuclide. Determination of the angular momentum J, the parity {pi}, and the isospin T from resonance capture data is considered. Special emphasis is placed on the capture angular distributions and on a geometric description of these angular distributions. {copyright} {ital 1997 American Institute of Physics.}

  10. Carbon capture by hybrid separation processes

    NARCIS (Netherlands)

    van Benthum, R.J.; van Kemenade, H.P.; Brouwers, J.J.H.

    2014-01-01

    Even though there is an increasing development of carbon capture technology over the last decade, large-scale implementation is still far from common practice, mainly caused by the energy intensiveness of carbon capture processes and the lack of regulation. In absence of strict regulation, less

  11. Numerical Prediction of Green Water Incidents

    DEFF Research Database (Denmark)

    Nielsen, K. B.; Mayer, Stefan

    2004-01-01

    loads on a moored FPSO exposed to head sea waves. Two cases are investigated: first, green water ona fixed vessel has been analysed, where resulting waterheight on deck, and impact pressure on a deck mounted structure have been computed. These results have been compared to experimental data obtained......Green water loads on moored or sailing ships occur when an incoming wave signigicantly exceeds the freeboard and water runs onto the deck. In this paper, a Navier-Stokes solver with a free surface capturing scheme (i.e. the VOF model; Hirt and Nichols, 1981) is used to numerically model green water...... by Greco (2001) and show very favourable agreement. Second, a full green water incident, including vessel motions has been modelled. In these computations, the vertical motion has been modelled by the use of transfer functions for heave and pitch, but the rotational contribution from the pitch motion has...

  12. Numerical Analysis of Magnetic Sail Spacecraft

    International Nuclear Information System (INIS)

    Sasaki, Daisuke; Yamakawa, Hiroshi; Usui, Hideyuki; Funaki, Ikkoh; Kojima, Hirotsugu

    2008-01-01

    To capture the kinetic energy of the solar wind by creating a large magnetosphere around the spacecraft, magneto-plasma sail injects a plasma jet into a strong magnetic field produced by an electromagnet onboard the spacecraft. The aim of this paper is to investigate the effect of the IMF (interplanetary magnetic field) on the magnetosphere of magneto-plasma sail. First, using an axi-symmetric two-dimensional MHD code, we numerically confirm the magnetic field inflation, and the formation of a magnetosphere by the interaction between the solar wind and the magnetic field. The expansion of an artificial magnetosphere by the plasma injection is then simulated, and we show that the magnetosphere is formed by the interaction between the solar wind and the magnetic field expanded by the plasma jet from the spacecraft. This simulation indicates the size of the artificial magnetosphere becomes smaller when applying the IMF.

  13. The Influence of Illustrations on Children's Comprehension of Written Stories.

    Science.gov (United States)

    O'Keefe, Elizabeth J.; Solman, Robert T.

    1987-01-01

    Examines the effect of a variety of picture-text conditions on third and fifth grade average readers' comprehension. Concludes that the advantage of presenting children of normal reading ability with illustrated text is small and primarily dependent on the placement of illustrations adjacent to related textual materials. (RS)

  14. Alignment in double capture processes

    Energy Technology Data Exchange (ETDEWEB)

    Moretto-Capelle, P.; Benhenni, M.; Bordenave-Montesquieu, A.; Benoit-Cattin, P.; Gleizes, A. (IRSAMC, URA CNRS 770, Univ. Paul Sabatier, 118 rte de Narbonne, 31062 Toulouse Cedex (France))

    1993-06-05

    The electron spectra emitted when a double capture occurs in N[sup 7+]+He and Ne[sup 8+]+He systems at 10 qkeV collisional energy, allow us to determine the angular distributions of the 3[ell]3[ell] [prime] lines through a special spectra fitting procedure which includes interferences between neighbouring states. It is found that the doubly excited states populated in double capture processes are generally aligned.

  15. Toward transformational carbon capture systems

    Energy Technology Data Exchange (ETDEWEB)

    Miller, David C. [National Energy Technology Laboratory, U.S. Dept. of Energy, Pittsburgh PA (United States); Litynski, John T. [Office of Fossil Energy, U.S. Dept. of Energy, Washington DC (United States); Brickett, Lynn A. [National Energy Technology Laboratory, U.S. Dept. of Energy, Pittsburgh PA (United States); Morreale, Bryan D. [National Energy Technology Laboratory, U.S. Dept. of Energy, Pittsburgh PA (United States)

    2015-10-28

    This paper will briefly review the history and current state of Carbon Capture and Storage (CCS) research and development and describe the technical barriers to carbon capture. it will argue forcefully for a new approach to R&D, which leverages both simulation and physical systems at the laboratory and pilot scales to more rapidly move the best technoogies forward, prune less advantageous approaches, and simultaneously develop materials and processes.

  16. Carbon Capture: A Technology Assessment

    Science.gov (United States)

    2013-10-21

    whereas laboratory-scale experiments typically seek to validate or obtain data for specific components of a system. Laboratory- and bench-scale processes...Plant,” Energy, vol. 35 (2010), pp. 841-850. E. Favre, R. Bounaceur, and D. Roizard, “ Biogas , Membranes and Carbon Dioxide Capture,” Journal of...pp. 1-49. 64 Favre, “ Biogas , Membranes.” Carbon Capture: A Technology Assessment Congressional Research Service 42 materials have pore sizes

  17. Audiovisual Capture with Ambiguous Audiovisual Stimuli

    Directory of Open Access Journals (Sweden)

    Jean-Michel Hupé

    2011-10-01

    Full Text Available Audiovisual capture happens when information across modalities get fused into a coherent percept. Ambiguous multi-modal stimuli have the potential to be powerful tools to observe such effects. We used such stimuli made of temporally synchronized and spatially co-localized visual flashes and auditory tones. The flashes produced bistable apparent motion and the tones produced ambiguous streaming. We measured strong interferences between perceptual decisions in each modality, a case of audiovisual capture. However, does this mean that audiovisual capture occurs before bistable decision? We argue that this is not the case, as the interference had a slow temporal dynamics and was modulated by audiovisual congruence, suggestive of high-level factors such as attention or intention. We propose a framework to integrate bistability and audiovisual capture, which distinguishes between “what” competes and “how” it competes (Hupé et al., 2008. The audiovisual interactions may be the result of contextual influences on neural representations (“what” competes, quite independent from the causal mechanisms of perceptual switches (“how” it competes. This framework predicts that audiovisual capture can bias bistability especially if modalities are congruent (Sato et al., 2007, but that is fundamentally distinct in nature from the bistable competition mechanism.

  18. Numerical simulation of nonlinear continuity equations by evolving diffeomorphisms

    KAUST Repository

    Carrillo, José A.

    2016-09-22

    In this paper we present a numerical scheme for nonlinear continuity equations, which is based on the gradient flow formulation of an energy functional with respect to the quadratic transportation distance. It can be applied to a large class of nonlinear continuity equations, whose dynamics are driven by internal energies, given external potentials and/or interaction energies. The solver is based on its variational formulation as a gradient flow with respect to the Wasserstein distance. Positivity of solutions as well as energy decrease of the semi-discrete scheme are guaranteed by its construction. We illustrate this property with various examples in spatial dimension one and two.

  19. Injection and temporary capture of a charged particle beam in an open magnetic configuration. Optimization of the configuration. Case of cylindrical symmetry: A mirror machine

    International Nuclear Information System (INIS)

    Capdequi-Peyranere, P.

    1966-12-01

    A study has been made of a new method of transverse injection of charged particles into a magnetic mirror configuration. This injection scheme permits the penetration and temporary capture by non-adiabatic effect of a particle beam of approximately 1 cm 2 cross-section. A theoretical study of the injection and capture is made in the approximation that space charge is negligible. The original programs for IBM 7094 computer calculations are described; these programs were used to obtain an optimization of the configuration. The results of a statistical numerical study of the optimum configuration are then given. This study indicates that, if the energy of the particles of the beam is about 1 per cent greater than a minimum penetration energy, the entire beam can be captured with an average capture length of 100 meters (50 reflections between the two mirrors). If the energy is about 4 per cent greater than the minimum penetration energy, the capture length is reduced to 40 meters. We have studied the distribution of energy transverse and longitudinal with the magnetic field for the population of captured particles. For the cases of injected molecular hydrogen ions or heavy CH 4 + ions, a study is made of the capture time of protons resulting from the dissociation of the ions by collisions with the neutral gas. Finally, we describe a model experiment using electrons designed to provide an experimental verification of the capture of the primary beam. (author) [fr

  20. The Use of Illustrations in Large-Scale Science Assessment: A Comparative Study

    Science.gov (United States)

    Wang, Chao

    2012-01-01

    This dissertation addresses the complexity of test illustrations design across cultures. More specifically, it examines how the characteristics of illustrations used in science test items vary across content areas, assessment programs, and cultural origins. It compares a total of 416 Grade 8 illustrated items from the areas of earth science, life…