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Sample records for richardson preyer buckridge

  1. John Reginald Richardson

    International Nuclear Information System (INIS)

    Craddock, M.K.

    1999-01-01

    The recent death of Reg Richardson has robbed the cyclotron community of its most senior figure. His many achievements over a long career include the first demonstration of phase stability, the first synchrocyclotron, the first sector-focused cyclotron, and one of the two cyclotron meson factories. (authors)

  2. Steele Richardson Olszewski syndrome

    Directory of Open Access Journals (Sweden)

    Vijayashree S Gokhale

    2013-01-01

    Full Text Available Parkinson′s disease and its plus syndromes are an important cause of morbidity in the geriatric age group. Its plus syndromes show a myriad of clinical features characterized by progressive symptoms. Here we present a 65-year-old woman with progressive "Parkinsonian-like features," i.e., mask-like face, slowness of all movements and tendency to fall, and difficulty in eye movements, leading to the diagnosis of Steele Richardson Olszewski Syndrome or progressive supranuclear palsy.

  3. Memoirs of Eileen Richardson

    Index Scriptorium Estoniae

    Richardson, Eileen

    2010-01-01

    Bournemouthi Ülikooli professor Eileen Richardson projektist ”Inequalities in access to rural communities”, mis on mõeldud Kanada ja Euroopa tervishoiuerialade tudengitele ning mille eesmärgiks on edendada erinevate tervishoiuerialade tudengite vahetust, rajada õpetlaste ja töötavate tervishoiuspetsialistide võrgustik arendamaks välja ühised õppekavad ja juhendid. Projektiga ühines ka Tallinna Tervishoiu Kõrgkool

  4. A Freudian Reading of Samuel Richardson's Pamela

    Directory of Open Access Journals (Sweden)

    Shadi Torabi Sarijaloo

    2016-03-01

    Full Text Available Richardson's Pamela (1740_1 is replete with elements and incidents that make it worthy enough to be viewed from Freud's perspective. The present study focuses upon how Richardson's characters unconsciously attempt to conceal and repress their own conflicting emotions, thoughts, wishes, impulses and how they struggle against their anxiety-ridden situations to regain their psychic balance. Moreover, the repetition of certain occurrences and elements play a crucial role in generating the uncanny effect in Pamela, including the role of double and déjà-vu, the castle-like settings, heroine's intimidating situations and also her master's past secret. In addition, the way Richardson's characters dress for the noteworthy masquerade ball scene and the ambiguous words of Pamela's master are considerably implies something that is affiliated with characters' psyche according to Freud's condensation theory. With regard to Freud's concepts of The 'Tripartite Psyche', 'Anxiety and Ego Defense Mechanisms' and 'Uncanny' the researcher attempts to delve into the heroine and her master's psyche through her letters which reveal the contents of the heroine's unconscious mind.

  5. Estimation of MONIN-OBUKHOV length using richardson and bulk richardson number

    International Nuclear Information System (INIS)

    Essa, K.S.M.

    2000-01-01

    The 1996 NOVA atmospheric boundary layer data from North Carolina are used in 30 minute's averages for five days. Because of missing data of friction velocity (u) and sensible heat flux (H), it is urgent to calculate (u*)and (H) using the equations of logarithmic wind speed and net radiation (Briggs [7]), which are considered in this work. It is found that the correlation between the predicted and observed values of (u*) and (H) is 0.88 and 0.86 respectively. A comparison is made of the Monin-Obukhov length scale (L) estimated using Richardson number (R i ) and bulk Richardson number (Ri b ) with L-value computed using formula of (L), it is found that the agreement between the predicted and observed values of (L) is better in the case (L)is estimated from the bulk Richardson number (Ri b ), rather than from the gradient Richarson number(R j )

  6. Another Vision of Progressivism: Marion Richardson's Triumph and Tragedy.

    Science.gov (United States)

    Smith, Peter

    1996-01-01

    Profiles the career and contributions of English art teacher Marion Richardson (1892-1946). A dynamic and assertive woman, Richardson's ideas and practices changed British primary and secondary art teaching for many years. She often used "word pictures" (narrative descriptions of scenes or emotions) to inspire her students. (MJP)

  7. Marion Richardson: "Art and the Child," a Forgotten Classic

    Science.gov (United States)

    Armstrong, Michael

    2015-01-01

    Marion Richardson was a revolutionary art teacher and schools inspector. First published in 1948, her book "Art and the Child" is one of the most remarkable educational documents of the period between the first and second world wars. This article reviews Richardson's philosophy and practice of art and suggests its continuing…

  8. Richardson effects in turbulent buoyant flows

    Science.gov (United States)

    Biggi, Renaud; Blanquart, Guillaume

    2010-11-01

    Rayleigh Taylor instabilities are found in a wide range of scientific fields from supernova explosions to underwater hot plumes. The turbulent flow is affected by the presence of buoyancy forces and may not follow the Kolmogorov theory anymore. The objective of the present work is to analyze the complex interactions between turbulence and buoyancy. Towards that goal, simulations have been performed with a high order, conservative, low Mach number code [Desjardins et. al. JCP 2010]. The configuration corresponds to a cubic box initially filled with homogeneous isotropic turbulence with heavy fluid on top and light gas at the bottom. The initial turbulent field was forced using linear forcing up to a Reynolds number of Reλ=55 [Meneveau & Rosales, POF 2005]. The Richardson number based on the rms velocity and the integral length scale was varied from 0.1 to 10 to investigate cases with weak and strong buoyancy. Cases with gravity as a stabilizer of turbulence (gravity pointing up) were also considered. The evolution of the turbulent kinetic energy and the total kinetic energy was analyzed and a simple phenomenological model was proposed. Finally, the energy spectra and the isotropy of the flow were also investigated.

  9. Black carp (Mylopharyngodon piceus, Richardson. Thematic bibliography

    Directory of Open Access Journals (Sweden)

    I. Hrytsynyak

    2017-03-01

    Full Text Available Purpose. Creating a thematic bibliographic list of publications in Ukrainian and Russian, dedicated to the ecology, biology, selection and cultivation of such Far East fish fauna species as black carp (Mylopharyngodon piceus Richardson in conditions of fish farms of Ukraine and neighboring countries, as well as the possibility of it introduction into water bodies for bioameliorative purpose. Methodology. The complete and selective methods were applied in the process of the systematic search. The bibliographic core has been formed with the literature from the fund of the scientific library of the Institute of Fisheries NAAS. Findings. There was composed a thematic list of publications with a total quantity of 67 sources, containing characteristics of black carp as representative of cyprinids, which is very important species from the point of view of aquaculture. This bibliography covers the time period from 1949 till 2011.The literary sources were arranged in alphabetical order by author or title, and described according to DSTU 7.1:2006 «System of standards on information, librarianship and publishing. Bibliographic entry. Bibliographic description. General requirements and rules», as well as in accordance with the requirements of APA style — international standard of references. Practical value. The list may be useful for scientists, practitioners, students, whose area of interests covers the questions of breeding and study of the biological features of black carp.

  10. Richardson Number, stability and turbulence- A coherent view

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.

    As turbulence in water is governed by vertical mobility controlled by static stability and horizontal mobility controlled by currents, the Richardson Number should give a measure of turbulence also. It is argued in this note that inverse...

  11. Vanishing of Littlewood-Richardson polynomials is in P

    OpenAIRE

    Adve, Anshul; Robichaux, Colleen; Yong, Alexander

    2017-01-01

    J. DeLoera-T. McAllister and K. D. Mulmuley-H. Narayanan-M. Sohoni independently proved that determining the vanishing of Littlewood-Richardson coefficients has strongly polynomial time computational complexity. Viewing these as Schubert calculus numbers, we prove the generalization to the Littlewood-Richardson polynomials that control equivariant cohomology of Grassmannians. We construct a polytope using the edge-labeled tableau rule of H. Thomas-A. Yong. Our proof then combines a saturation...

  12. Solving the Richardson equations close to the critical points

    Energy Technology Data Exchange (ETDEWEB)

    DomInguez, F [Departamento de Matematicas, Universidad de Alcala, 28871 Alcala de Henares (Spain); Esebbag, C [Departamento de Matematicas, Universidad de Alcala, 28871 Alcala de Henares (Spain); Dukelsky, J [Instituto de Estructura de la Materia, CSIC, Serrano 123, 28006 Madrid (Spain)

    2006-09-15

    We study the Richardson equations close to the critical values of the pairing strength g{sub c}, where the occurrence of divergences precludes numerical solutions. We derive a set of equations for determining the critical g values and the non-collapsing pair energies. Studying the behaviour of the solutions close to the critical points, we develop a procedure to solve numerically the Richardson equations for arbitrary coupling strength.

  13. Parametrization of the Richardson weather generator within the European Union

    NARCIS (Netherlands)

    Voet, van der P.; Kramer, K.; Diepen, van C.A.

    1996-01-01

    The Richardson model for mathematically generating daily weather data was parametrized. Thirty years' time-series of the 355 main meteorological stations in the European Union formed the database. Model parameters were derived from both observed weather station data and interpolated weather data on

  14. Noisy Spins and the Richardson-Gaudin Model

    Science.gov (United States)

    Rowlands, Daniel A.; Lamacraft, Austen

    2018-03-01

    We study a system of spins (qubits) coupled to a common noisy environment, each precessing at its own frequency. The correlated noise experienced by the spins implies long-lived correlations that relax only due to the differing frequencies. We use a mapping to a non-Hermitian integrable Richardson-Gaudin model to find the exact spectrum of the quantum master equation in the high-temperature limit and, hence, determine the decay rate. Our solution can be used to evaluate the effect of inhomogeneous splittings on a system of qubits coupled to a common bath.

  15. Spectral inversion of an indefinite Sturm-Liouville problem due to Richardson

    International Nuclear Information System (INIS)

    Shanley, Paul E

    2009-01-01

    We study an indefinite Sturm-Liouville problem due to Richardson whose complicated eigenvalue dependence on a parameter has been a puzzle for decades. In atomic physics a process exists that inverts the usual Schroedinger situation of an energy eigenvalue depending on a coupling parameter into the so-called Sturmian problem where the coupling parameter becomes the eigenvalue which then depends on the energy. We observe that the Richardson equation is of the Sturmian type. This means that the Richardson and its related Schroedinger eigenvalue functions are inverses of each other and that the Richardson spectrum is therefore no longer a puzzle

  16. Briti ekspert : euroliidus kaob Eestist tööpuudus / Michael Richardson ; interv. Airi Ilisson

    Index Scriptorium Estoniae

    Richardson, Michael

    2003-01-01

    Eestis Suurbritannia tööreformi tutvustava töö- ja sotsiaalnõuniku sõnul on Suurbritannias peaaegu kadunud pikaajaline töötus noorte hulgas, vanematest inimestest on vaid üksikud tööta kauem kui aasta. Vt. samas: Kes on Michael Richardson?

  17. Double cascade turbulence and Richardson dispersion in a horizontal fluid flow induced by Faraday waves.

    Science.gov (United States)

    von Kameke, A; Huhn, F; Fernández-García, G; Muñuzuri, A P; Pérez-Muñuzuri, V

    2011-08-12

    We report the experimental observation of Richardson dispersion and a double cascade in a thin horizontal fluid flow induced by Faraday waves. The energy spectra and the mean spectral energy flux obtained from particle image velocimetry data suggest an inverse energy cascade with Kolmogorov type scaling E(k) ∝ k(γ), γ ≈ -5/3 and an E(k) ∝ k(γ), γ ≈ -3 enstrophy cascade. Particle transport is studied analyzing absolute and relative dispersion as well as the finite size Lyapunov exponent (FSLE) via the direct tracking of real particles and numerical advection of virtual particles. Richardson dispersion with ∝ t(3) is observed and is also reflected in the slopes of the FSLE (Λ ∝ ΔR(-2/3)) for virtual and real particles.

  18. EGS Richardson AGU Chapman NVAG3 Conference: Nonlinear Variability in Geophysics: scaling and multifractal processes

    OpenAIRE

    D. Schertzer; S. Lovejoy; S. Lovejoy

    1994-01-01

    1. The conference The third conference on "Nonlinear VAriability in Geophysics: scaling and multifractal processes" (NVAG 3) was held in Cargese, Corsica, Sept. 10-17, 1993. NVAG3 was joint American Geophysical Union Chapman and European Geophysical Society Richardson Memorial conference, the first specialist conference jointly sponsored by the two organizations. It followed NVAG1 (Montreal, Aug. 1986), NVAG2 (Paris, June 1988; Schertzer and Lovejoy, 1991), five consecutive annual ...

  19. EGS Richardson AGU Chapman NVAG3 Conference: Nonlinear Variability in Geophysics: scaling and multifractal processes

    OpenAIRE

    Schertzer , D; Lovejoy , S.

    1994-01-01

    International audience; 1. The conference The third conference on "Nonlinear VAriability in Geophysics: scaling and multifractal processes" (NVAG 3) was held in Cargese, Corsica, Sept. 10-17, 1993. NVAG3 was joint American Geophysical Union Chapman and European Geophysical Society Richardson Memorial conference, the first specialist conference jointly sponsored by the two organizations. It followed NVAG1 (Montreal, Aug. 1986), NVAG2 (Paris, June 1988; Schertzer and Lovejoy, 1991), five conse...

  20. Deconvolution of 2D coincident Doppler broadening spectroscopy using the Richardson-Lucy algorithm

    International Nuclear Information System (INIS)

    Zhang, J.D.; Zhou, T.J.; Cheung, C.K.; Beling, C.D.; Fung, S.; Ng, M.K.

    2006-01-01

    Coincident Doppler Broadening Spectroscopy (CDBS) measurements are popular in positron solid-state studies of materials. By utilizing the instrumental resolution function obtained from a gamma line close in energy to the 511 keV annihilation line, it is possible to significantly enhance the quality of the CDBS spectra using deconvolution algorithms. In this paper, we compare two algorithms, namely the Non-Negativity Least Squares (NNLS) regularized method and the Richardson-Lucy (RL) algorithm. The latter, which is based on the method of maximum likelihood, is found to give superior results to the regularized least-squares algorithm and with significantly less computer processing time

  1. The contributions of Lewis Fry Richardson to drainage theory, soil physics, and the soil-plant-atmosphere continuum

    Science.gov (United States)

    Knight, John; Raats, Peter

    2016-04-01

    The EGU Division on Nonlinear Processes in Geophysics awards the Lewis Fry Richardson Medal. Richardson's significance is highlighted in http://www.egu.eu/awards-medals/portrait-lewis-fry-richardson/, but his contributions to soil physics and to numerical solutions of heat and diffusion equations are not mentioned. We would like to draw attention to those little known contributions. Lewis Fry Richardson (1881-1953) made important contributions to many fields including numerical weather prediction, finite difference solutions of partial differential equations, turbulent flow and diffusion, fractals, quantitative psychology and studies of conflict. He invented numerical weather prediction during World War I, although his methods were not successfully applied until 1950, after the invention of fast digital computers. In 1922 he published the book `Numerical weather prediction', of which few copies were sold and even fewer were read until the 1950s. To model heat and mass transfer in the atmosphere, he did much original work on turbulent flow and defined what is now known as the Richardson number. His technique for improving the convergence of a finite difference calculation is known as Richardson extrapolation, and was used by John Philip in his 1957 semi-analytical solution of the Richards equation for water movement in unsaturated soil. Richardson's first papers in 1908 concerned the numerical solution of the free surface problem of unconfined flow of water in saturated soil, arising in the design of drain spacing in peat. Later, for the lower boundary of his atmospheric model he needed to understand the movement of heat, liquid water and water vapor in what is now called the vadose zone and the soil plant atmosphere system, and to model coupled transfer of heat and flow of water in unsaturated soil. Finding little previous work, he formulated partial differential equations for transient, vertical flow of liquid water and for transfer of heat and water vapor. He

  2. On Richardson extrapolation for low-dissipation low-dispersion diagonally implicit Runge-Kutta schemes

    Science.gov (United States)

    Havasi, Ágnes; Kazemi, Ehsan

    2018-04-01

    In the modeling of wave propagation phenomena it is necessary to use time integration methods which are not only sufficiently accurate, but also properly describe the amplitude and phase of the propagating waves. It is not clear if amending the developed schemes by extrapolation methods to obtain a high order of accuracy preserves the qualitative properties of these schemes in the perspective of dissipation, dispersion and stability analysis. It is illustrated that the combination of various optimized schemes with Richardson extrapolation is not optimal for minimal dissipation and dispersion errors. Optimized third-order and fourth-order methods are obtained, and it is shown that the proposed methods combined with Richardson extrapolation result in fourth and fifth orders of accuracy correspondingly, while preserving optimality and stability. The numerical applications include the linear wave equation, a stiff system of reaction-diffusion equations and the nonlinear Euler equations with oscillatory initial conditions. It is demonstrated that the extrapolated third-order scheme outperforms the recently developed fourth-order diagonally implicit Runge-Kutta scheme in terms of accuracy and stability.

  3. Intrusion of soil covered uranium mill tailings by whitetail prairie dogs and Richardson's ground squirrels

    International Nuclear Information System (INIS)

    Shuman, R.

    1984-01-01

    The primary objective of the reclamation of uranium mill tailings is the long-term isolation of the matrial from the biosphere. Fossorial and semi-fossorial species represent a potentially disruptive influence as a result of their burrowing habits. The potential for intrusion was investigated with respect to two sciurids, the whitetail prairie dog (Cynomys leucurus) and Richardson's ground squirrel (Spermophilus richardsonii). Populations of prairie dogs were established on a control area, lacking a tailings layer, and two experimental areas, underlain by a waste layer, in southeastern Wyoming. Weekly measurements of prairie dog mound surface activities were conducted to demonstrate penetration, or lack thereof, of the tailings layer. Additionally, the impact of burrowing upon radon flux was determined. Limited penetration of the waste layer was noted after which frequency of inhabitance of the intruding burrow system declined. No significant changes in radon flux were detected. In another experiment, it was found that Richardson's ground squirrels burrowed to less extreme depths when confronted by mill tailings. Additional work at an inactive tailings pile in western Colorado revealed repeated intrusion through a shallow cover, and subsequent transport of radioactive material to the ground surface by prairie dogs. Radon flux from burrow entrances was significantly greater than that from undisturbed ground. Data suggested that textural and pH properties of tailings material may act to discourage repeated intrusion at some sites. 58 references

  4. EGS Richardson AGU Chapman NVAG3 Conference: Nonlinear Variability in Geophysics: scaling and multifractal processes

    Directory of Open Access Journals (Sweden)

    D. Schertzer

    1994-01-01

    Full Text Available 1. The conference The third conference on "Nonlinear VAriability in Geophysics: scaling and multifractal processes" (NVAG 3 was held in Cargese, Corsica, Sept. 10-17, 1993. NVAG3 was joint American Geophysical Union Chapman and European Geophysical Society Richardson Memorial conference, the first specialist conference jointly sponsored by the two organizations. It followed NVAG1 (Montreal, Aug. 1986, NVAG2 (Paris, June 1988; Schertzer and Lovejoy, 1991, five consecutive annual sessions at EGS general assemblies and two consecutive spring AGU meeting sessions. As with the other conferences and workshops mentioned above, the aim was to develop confrontation between theories and experiments on scaling/multifractal behaviour of geophysical fields. Subjects covered included climate, clouds, earthquakes, atmospheric and ocean dynamics, tectonics, precipitation, hydrology, the solar cycle and volcanoes. Areas of focus included new methods of data analysis (especially those used for the reliable estimation of multifractal and scaling exponents, as well as their application to rapidly growing data bases from in situ networks and remote sensing. The corresponding modelling, prediction and estimation techniques were also emphasized as were the current debates about stochastic and deterministic dynamics, fractal geometry and multifractals, self-organized criticality and multifractal fields, each of which was the subject of a specific general discussion. The conference started with a one day short course of multifractals featuring four lectures on a Fundamentals of multifractals: dimension, codimensions, codimension formalism, b Multifractal estimation techniques: (PDMS, DTM, c Numerical simulations, Generalized Scale Invariance analysis, d Advanced multifractals, singular statistics, phase transitions, self-organized criticality and Lie cascades (given by D. Schertzer and S. Lovejoy, detailed course notes were sent to participants shortly after the

  5. EGS Richardson AGU Chapman NVAG3 Conference: Nonlinear Variability in Geophysics: scaling and multifractal processes

    Science.gov (United States)

    Schertzer, D.; Lovejoy, S.

    1. The conference The third conference on "Nonlinear VAriability in Geophysics: scaling and multifractal processes" (NVAG 3) was held in Cargese, Corsica, Sept. 10-17, 1993. NVAG3 was joint American Geophysical Union Chapman and European Geophysical Society Richardson Memorial conference, the first specialist conference jointly sponsored by the two organizations. It followed NVAG1 (Montreal, Aug. 1986), NVAG2 (Paris, June 1988; Schertzer and Lovejoy, 1991), five consecutive annual sessions at EGS general assemblies and two consecutive spring AGU meeting sessions. As with the other conferences and workshops mentioned above, the aim was to develop confrontation between theories and experiments on scaling/multifractal behaviour of geophysical fields. Subjects covered included climate, clouds, earthquakes, atmospheric and ocean dynamics, tectonics, precipitation, hydrology, the solar cycle and volcanoes. Areas of focus included new methods of data analysis (especially those used for the reliable estimation of multifractal and scaling exponents), as well as their application to rapidly growing data bases from in situ networks and remote sensing. The corresponding modelling, prediction and estimation techniques were also emphasized as were the current debates about stochastic and deterministic dynamics, fractal geometry and multifractals, self-organized criticality and multifractal fields, each of which was the subject of a specific general discussion. The conference started with a one day short course of multifractals featuring four lectures on a) Fundamentals of multifractals: dimension, codimensions, codimension formalism, b) Multifractal estimation techniques: (PDMS, DTM), c) Numerical simulations, Generalized Scale Invariance analysis, d) Advanced multifractals, singular statistics, phase transitions, self-organized criticality and Lie cascades (given by D. Schertzer and S. Lovejoy, detailed course notes were sent to participants shortly after the conference). This

  6. Fungsi Bangunan Dokwi Vam dan Kembu Vam Bagi Suku Yali dalam Novel Penguasa-penguasa Bumi Karya Don Richardson

    Directory of Open Access Journals (Sweden)

    Ummu Fatimah Ria Lestari

    2016-04-01

    Full Text Available This study discusses the function of the building of Dokwi Vam and Kembu Vam contained in the novel-Sovereign Ruler of the Earth works Don Richardson. In general, this novel tells the story of the life of Stan Dale and Yali tribe. Stan Dale is a missionary who served in Papua. He struggled to introduce Christianity to the Yali tribe. This study uses the description of the technical literature. This research resulted in a description of the function of the building of Dokwi Vam and Kembu Vam contained in the novel Lord of-Ruler of the Earth works Don Richardson. Dokwi Vam used as a museum (where the old stuff to worship as they still follow animism, while the Kembu Vam serves as a temple / animism worship in Yali tribe. Penelitian ini membahas tentang fungsi bangunan Dokwi Vam dan Kembu Vam yang terdapat dalam novel Penguasa-Penguasa Bumi karya Don Richardson. Secara umum, novel ini bercerita tentang kehidupan Stan Dale dan suku Yali. Stan Dale adalah seorang missionaris yang melayani di Tanah Papua. Ia berjuang untuk memperkenalkan agama Nasrani kepada suku Yali. Penelitian ini menggunakan metode deskripsi dengan teknik studi pustaka. Penelitian ini menghasilkan deskripsi tentang fungsi bangunan Dokwi Vam dan Kembu Vam yang terdapat dalam novel Penguasa-Penguasa Bumi karya Don Richardson. Dokwi Vam digunakan sebagai museum (tempat barang-barang kuno untuk penyembahan karena mereka masih menganut kepercayaan animisme, sedangkan Kembu Vam berfungsi sebagai rumah peribadatan/penyembahan dalam kepercayaan animisme suku Yali.

  7. Estimates of gradient Richardson numbers from vertically smoothed data in the Gulf Stream region

    Directory of Open Access Journals (Sweden)

    Paul van Gastel

    2004-12-01

    Full Text Available We use several hydrographic and velocity sections crossing the Gulf Stream to examine how the gradient Richardson number, Ri, is modified due to both vertical smoothing of the hydrographic and/or velocity fields and the assumption of parallel or geostrophic flow. Vertical smoothing of the original (25 m interval velocity field leads to a substantial increase in the Ri mean value, of the same order as the smoothing factor, while its standard deviation remains approximately constant. This contrasts with very minor changes in the distribution of the Ri values due to vertical smoothing of the density field over similar lengths. Mean geostrophic Ri values remain always above the actual unsmoothed Ri values, commonly one to two orders of magnitude larger, but the standard deviation is typically a factor of five larger in geostrophic than in actual Ri values. At high vertical wavenumbers (length scales below 3 m the geostrophic shear only leads to near critical conditions in already rather mixed regions. At these scales, hence, the major contributor to shear mixing is likely to come from the interaction of the background flow with internal waves. At low vertical wavenumbers (scales above 25 m the ageostrophic motions provide the main source for shear, with cross-stream movements having a minor but non-negligible contribution. These large-scale motions may be associated with local accelerations taking place during frontogenetic phases of meanders.

  8. Towards social autonomous vehicles: Efficient collision avoidance scheme using Richardson's arms race model.

    Science.gov (United States)

    Riaz, Faisal; Niazi, Muaz A

    2017-01-01

    This paper presents the concept of a social autonomous agent to conceptualize such Autonomous Vehicles (AVs), which interacts with other AVs using social manners similar to human behavior. The presented AVs also have the capability of predicting intentions, i.e. mentalizing and copying the actions of each other, i.e. mirroring. Exploratory Agent Based Modeling (EABM) level of the Cognitive Agent Based Computing (CABC) framework has been utilized to design the proposed social agent. Furthermore, to emulate the functionality of mentalizing and mirroring modules of proposed social agent, a tailored mathematical model of the Richardson's arms race model has also been presented. The performance of the proposed social agent has been validated at two levels-firstly it has been simulated using NetLogo, a standard agent-based modeling tool and also, at a practical level using a prototype AV. The simulation results have confirmed that the proposed social agent-based collision avoidance strategy is 78.52% more efficient than Random walk based collision avoidance strategy in congested flock-like topologies. Whereas practical results have confirmed that the proposed scheme can avoid rear end and lateral collisions with the efficiency of 99.876% as compared with the IEEE 802.11n-based existing state of the art mirroring neuron-based collision avoidance scheme.

  9. Diffusible gradients are out - an interview with Lewis Wolpert. Interviewed by Richardson, Michael K.

    Science.gov (United States)

    Wolpert, Lewis

    2009-01-01

    In 1969, Lewis Wolpert published a paper outlining his new concepts of "pattern formation" and "positional information". He had already published research on the mechanics of cell membranes in amoebae, and a series of classic studies of sea urchin gastrulation with Trygve Gustavson. Wolpert had presented his 1969 paper a year earlier at a Woods Hole conference, where it received a very hostile reception: "I wasnt asked back to America for many years!". But with Francis Crick lining up in support of diffusible morphogen gradients, positional information eventually became established as a guiding principle for research into biological pattern formation. It is now clear that pattern formation is much more complex than could possibly have been imagined in 1969. But Wolpert still believes in positional information, and regards intercalation during regeneration as its best supporting evidence. However, he and others doubt that diffusible morphogen gradients are a plausible mechanism: "Diffusible gradients are too messy", he says. Since his retirement, Lewis Wolpert has remained active as a theoretical biologist and continues to publish in leading journals. He has also campaigned for a greater public understanding of the stigma of depression. He was interviewed at home in London on July 26th, 2007 by Michael Richardson.

  10. Towards social autonomous vehicles: Efficient collision avoidance scheme using Richardson's arms race model.

    Directory of Open Access Journals (Sweden)

    Faisal Riaz

    Full Text Available This paper presents the concept of a social autonomous agent to conceptualize such Autonomous Vehicles (AVs, which interacts with other AVs using social manners similar to human behavior. The presented AVs also have the capability of predicting intentions, i.e. mentalizing and copying the actions of each other, i.e. mirroring. Exploratory Agent Based Modeling (EABM level of the Cognitive Agent Based Computing (CABC framework has been utilized to design the proposed social agent. Furthermore, to emulate the functionality of mentalizing and mirroring modules of proposed social agent, a tailored mathematical model of the Richardson's arms race model has also been presented. The performance of the proposed social agent has been validated at two levels-firstly it has been simulated using NetLogo, a standard agent-based modeling tool and also, at a practical level using a prototype AV. The simulation results have confirmed that the proposed social agent-based collision avoidance strategy is 78.52% more efficient than Random walk based collision avoidance strategy in congested flock-like topologies. Whereas practical results have confirmed that the proposed scheme can avoid rear end and lateral collisions with the efficiency of 99.876% as compared with the IEEE 802.11n-based existing state of the art mirroring neuron-based collision avoidance scheme.

  11. Active filtering applied to radiographic images unfolded by the Richardson-Lucy algorithm

    International Nuclear Information System (INIS)

    Almeida, Gevaldo L. de; Silvani, Maria Ines; Lopes, Ricardo T.

    2011-01-01

    Degradation of images caused by systematic uncertainties can be reduced when one knows the features of the spoiling agent. Typical uncertainties of this kind arise in radiographic images due to the non - zero resolution of the detector used to acquire them, and from the non-punctual character of the source employed in the acquisition, or from the beam divergence when extended sources are used. Both features blur the image, which, instead of a single point exhibits a spot with a vanishing edge, reproducing hence the point spread function - PSF of the system. Once this spoiling function is known, an inverse problem approach, involving inversion of matrices, can then be used to retrieve the original image. As these matrices are generally ill-conditioned, due to statistical fluctuation and truncation errors, iterative procedures should be applied, such as the Richardson-Lucy algorithm. This algorithm has been applied in this work to unfold radiographic images acquired by transmission of thermal neutrons and gamma-rays. After this procedure, the resulting images undergo an active filtering which fairly improves their final quality at a negligible cost in terms of processing time. The filter ruling the process is based on the matrix of the correction factors for the last iteration of the deconvolution procedure. Synthetic images degraded with a known PSF, and undergone to the same treatment, have been used as benchmark to evaluate the soundness of the developed active filtering procedure. The deconvolution and filtering algorithms have been incorporated to a Fortran program, written to deal with real images, generate the synthetic ones and display both. (author)

  12. The Lipkin-Meshkov-Glick model from the perspective of the SU(1,1) Richardson-Gaudin models

    International Nuclear Information System (INIS)

    Lerma-H, Sergio; Dukelsky, Jorge

    2014-01-01

    Originally introduced in nuclear physics as a numerical laboratory to test different many-body approximation methods, the Lipkin-Meshkov-Glick (LMG) model has received much attention as a simple enough but non-trivial model with many interesting features for areas of physics beyond the nuclear one. In this contribution we look at the LMG model as a particular example of an SU(1,1) Richardson-Gaudin model. The characteristics of the model are analyzed in terms of the behavior of the spectral-parameters or pairons which determine both eigenvalues and eigenfunctions of the model Hamiltonian. The problem of finding these pairons is mathematically equivalent to obtain the equilibrium positions of a set of electric charges moving in a two dimensional space. The electrostatic problems for the different regions of the model parameter space are discussed and linked to the different energy density of states already identified in the LMG spectrum.

  13. Comparative evaluation of the modified Scarff-Bloom-Richardson grading system on breast carcinoma aspirates and histopathology

    Directory of Open Access Journals (Sweden)

    Cherry Bansal

    2012-01-01

    Full Text Available Background: Fine needle aspiration (FNA is a quick, minimally invasive procedure for evaluation of breast tumors. The Scarff-Bloom-Richardson (SBR grade on histological sections is a well-established tool to guide selection of adjuvant systemic therapy. Grade evaluation is possible on cytology smears to avoid and minimize the morbidity associated with overtreatment of lower grade tumors. Aim : The aim was to test the hypothesis whether breast FNA from the peripheral portion of the lesion is representative of Scarff-Bloom-Richardson grade on histopathology as compared to FNA from the central portion. Materials and Methods : Fine-needle aspirates and subsequent tissue specimens from 45 women with ductal carcinoma (not otherwise specified were studied. FNAs were performed under ultrasound guidance from the central as well as the peripheral third of the lesion for each case avoiding areas of necrosis/calcification. The SBR grading was compared on alcohol fixed aspirates and tissue sections for each case. Results : Comparative analysis of SBR grade on aspirates from the peripheral portion and histopathology by the Pearson chi-square test (χ2 =78.00 showed that it was statistically significant (P<0.001 with 93% concordance. Lower mitotic score on aspirates from the peripheral portion was observed in only 4 out of 45 (9% cases. The results of the Pearson chi-square test (χ2 = 75.824 with statistically significant (P=0.000. Conclusion : This prospective study shows that FNA smears from the peripheral portion of the lesion are representative of the grading performed on the corresponding histopathological sections. It is possible to score and grade by SBR system on FNA smears.

  14. Richardson Instructional Management System (RIMS). How to Blend a Computerized Objectives-Referenced Testing System, Distributive Data Processing, and Systemwide Evaluation.

    Science.gov (United States)

    Riegel, N. Blyth

    Recent changes in the structure of curriculum and the instructional system in Texas have required a major reorganization of teaching, evaluating, budgeting, and planning activities in the local education agencies, which has created the need for a database. The history of Richardson Instructional Management System (RIMS), its data processing…

  15. Studies on mixing of the waters of different salinity gradients using Richardsons number and the suspended sediment distribution in the Beypore Estuary, south west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    AnilKumar, N.; Sankaranarayanan, V.N.; Josanto, V.

    of Richardsons number (log R sub(L)) shows high variation at river mouth section of the estuary (section-1) and at about 10 km upstream (section-2) during the postmonsoon period. During the premonsoon period there was no noticeable variation in log R sub...

  16. Influence of the beam divergence on the quality neutron radiographic images improved by Richardson-Lucy deconvolution

    International Nuclear Information System (INIS)

    Almeida, Gevaldo L. de; Silvani, Maria Ines; Lopes, Ricardo T.

    2010-01-01

    Full text: Images produced by radiation transmission, as many others, are affected by disturbances caused by random and systematic uncertainties. Those caused by noise or statistical dispersion can be diminished by a filtering procedure which eliminates high-frequencies associated to the noise, but unfortunately also those belonging to the signal itself. Systematic uncertainties, in principle, could be more effectively removed if one knows the spoiling convolution function causing the degradation of the image. This function depends upon the detector resolution and the non-punctual character of the source employed in the acquisition, which blur the image making a single point to appear as a spot with a vanishing edge. For an extended source, exhibiting however a reasonable parallel beam, the penumbra degrading the image would be caused by the unavoidable beam divergence. In both cases, the essential information to improve the degraded image is the law of transformation of a single point into a blurred spot, known as point spread function-PSF. Even for an isotropic system, where this function would have a symmetric bell-like shape, it is very difficult to obtain experimentally and to apply it to the data processing. For this reason it is usually replaced by an approximated analytical function such as a Gaussian or Lorentzian. In this work, the Richardson-Lucy deconvoultion has been applied to ameliorate thermal neutron radiographic images acquired with imaging plates using a Gaussian PSF as deconvolutor. Due to the divergence of the neutron beam, reaching 1 deg 16', the penumbra affecting the final image depends upon the gap object-detector. Moreover, even if the object were placed in direct contact with the detector the non-zero dimension of the object along the beam path would produce penumbrae of different magnitudes, i.e., the spatial resolution of the system would be dependent upon the object-detector arrangement. This means that the width of the PSF increases

  17. Comparison of regional brain atrophy and cognitive impairment between pure akinesia with gait freezing and Richardson's syndrome

    Science.gov (United States)

    Hong, Jin Yong; Yun, Hyuk Jin; Sunwoo, Mun Kyung; Ham, Jee Hyun; Lee, Jong-Min; Sohn, Young H.; Lee, Phil Hyu

    2015-01-01

    Pure akinesia with gait freezing (PAGF) is considered a clinical phenotype of progressive supranuclear palsy. The brain atrophy and cognitive deficits in PAGF are expected to be less prominent than in classical Richardson's syndrome (RS), but this hypothesis has not been explored yet. We reviewed the medical records of 28 patients with probable RS, 19 with PAGF, and 29 healthy controls, and compared cortical thickness, subcortical gray matter volume, and neuropsychological performance among the three groups. Patients with PAGF had thinner cortices in frontal, inferior parietal, and temporal areas compared with controls; however, areas of cortical thinning in PAGF patients were less extensive than those in RS patients. In PAGF patients, hippocampal, and thalamic volumes were also smaller than controls, whereas subcortical gray matter volumes in PAGF and RS patients were comparable. In a comparison of neuropsychological tests, PAGF patients had better cognitive performance in executive function, visual memory, and visuospatial function than RS patients had. These results demonstrate that cognitive impairment, cortical thinning, and subcortical gray matter atrophy in PAGF patients resemble to those in RS patients, though the severity of cortical thinning and cognitive dysfunction is milder. Our results suggest that, PAGF and RS may share same pathology but that it appears to affect a smaller proportion of the cortex in PAGF. PMID:26483680

  18. Interim Report on the Investigation of the Fresh Properties of Synthetic Fiber-Reinforced Concrete for the Richardson Landing Casting Field

    Science.gov (United States)

    2017-04-01

    PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER U.S. Army Engineer Research and Development Center Geotechnical ...2017 Approved for public release; distribution is unlimited. The U.S. Army Engineer Research and Development Center (ERDC) solves the...the Richardson Landing Casting Field Wendy R. Long, Kirk E. Walker, and Brian H. Green Geotechnical and Structures Laboratory U.S. Army Engineer

  19. "Self-critical perfectionism, daily stress, and disclosure of daily emotional events": Correction to Richardson and Rice (2015).

    Science.gov (United States)

    2016-01-01

    Reports an error in "Self-critical perfectionism, daily stress, and disclosure of daily emotional events" by Clarissa M. E. Richardson and Kenneth G. Rice (Journal of Counseling Psychology, 2015[Oct], Vol 62[4], 694-702). In the article, the labels of the two lines in Figure 1 were inadvertently transposed. The dotted line should be labeled High SCP and the solid line should be labeled Low SCP. The correct version is present in the erratum. (The following abstract of the original article appeared in record 2015-30890-001.) Although disclosure of stressful events can alleviate distress, self-critical perfectionism may pose an especially strong impediment to disclosure during stress, likely contributing to poorer psychological well-being. In the current study, after completing a measure of self-critical perfectionism (the Discrepancy subscale of the Almost Perfect Scale-Revised; Slaney, Rice, Mobley, Trippi, & Ashby, 2001), 396 undergraduates completed measures of stress and disclosure at the end of each day for 1 week. Consistent with hypotheses and previous research, multilevel modeling results indicated significant intraindividual coupling of daily stress and daily disclosure where disclosure was more likely when experiencing high stress than low stress. As hypothesized, Discrepancy moderated the relationship between daily stress and daily disclosure. Individuals higher in self-critical perfectionism (Discrepancy) were less likely to engage in disclosure under high stress, when disclosure is often most beneficial, than those with lower Discrepancy scores. These results have implications for understanding the role of stress and coping in the daily lives of self-critical perfectionists. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  20. The pattern of verbal, visuospatial and procedural learning in Richardson variant of progressive supranuclear palsy in comparison to Parkinson's disease.

    Science.gov (United States)

    Sitek, Emilia J; Wieczorek, Dariusz; Konkel, Agnieszka; Dąbrowska, Magda; Sławek, Jarosław

    2017-08-29

    Progressive supranuclear palsy (PSP) is regarded either within spectrum of atypical parkinsonian syndromes or frontotemporal lobar degeneration. We compared the verbal, visuospatial and procedural learning profiles in patients with PSP and Parkinson's disease (PD). Furthermore, the relationship between executive factors (initiation and inhibition) and learning outcomes was analyzed. Thirty-three patients with the clinical diagnosis of PSP-Richardson's syndrome (PSP-RS), 39 patients with PD and 29 age -and education -matched controls were administered Mini-Mental State Examination (MMSE), phonemic and semantic fluency tasks, Auditory Verbal Learning Test (AVLT), Visual Learning and Memory Test for Neuropsychological Assessment by Lamberti and Weidlich (Diagnosticum für Cerebralschädigung, DCS), Tower of Toronto (ToT) and two motor sequencing tasks. Patients with PSP-RS and PD were matched in terms of MMSE scores and mood. Performance on DCS was lower in PSP-RS than in PD. AVLT delayed recall was better in PSP-RS than PD. Motor sequencing task did not differentiate between patients. Scores on AVLT correlated positively with phonemic fluency scores in both PSP-RS and PD. ToT rule violation scores were negatively associated with DCS performance in PSP-RS and PD as well as with AVLT performance in PD. Global memory performance is relatively similar in PSP-RS and PD. Executive factors (initiation and inhibition) are closely related to memory performance in PSP-RS and PD. Visuospatial learning impairment in PSP-RS is possibly linked to impulsivity and failure to inhibit automatic responses.

  1. Richardson WCAP 39

    African Journals Online (AJOL)

    user

    Peer-reviewed paper: 10th World Conference on Animal Production. 204. Results and Discussion. The model was evaluated by comparing model output with the results of an experiment in South. Western Zimbabwe that examined the performance of individual cows subjected to widely different stocking rates, 0.123 (LSR) ...

  2. Nucleon and isobar properties in a relativistic Hartree-Fock calculation with vector Richardson potential and various radial forms for scalar mass terms

    International Nuclear Information System (INIS)

    Dey, J.; Dey, M.; Mukhopadhyay, G.; Samanta, B.C.

    1989-01-01

    Mean field models of the nucleon and the delta are established with the two-quark vector Richardson potential along with various prescriptions for a running quark mass. This is taken to be a one-particle operator in the Dirac-Hartree Fock formalism. An effective density dependent one body potential U(ρ) for quarks at a given density ρ inside the nucleon is derived. It shows an interesting structure. Asymptotic freedom and confinement properties are built-in at high and low densities in U (ρ) and the model dependence is restricted to the intermediate desnsities. (author) [pt

  3. US Department of Energy Secretary Bill Richardson (centre) at an LHC interaction region quadrupole test cryostat. part of the US contribution to LHC construction and built by the US-LHC collaboration (hence the Fermilab logo)

    CERN Multimedia

    Barbara Warmbein

    2000-01-01

    Photo 01 : September 2000 - Mr Bill Richardson, Secretary of Energy, United States of America (centre) at an LHC interaction region quadrupole test cryostat, part of the US contribution to LHC construction and built by the US-LHC collaboration (hence the Fermilab logo); with l. to r. Dr Mildred Dresselhaus, Dr Carlo Wyss, CERN Director General, Profesor Luciano Maiani, Professor Roger Cashmore, Ambassador George Moose, Dr Peter Rosen, Dr John Ellis. Photo 02 : Mr. Bill Richardson (right), Secretary of Energy United States of America with Prof. Luciano Maiani leaning over one of the LHC magnets produced at Fermilab during his visit to CERN on 16th September 2000.

  4. The history of NATO TNF policy: The role of studies, analysis and exercises conference proceedings. Volume 3: Papers by Gen. Robert C. Richardson III (Ret.)

    Energy Technology Data Exchange (ETDEWEB)

    Rinne, R.L. [ed.

    1994-02-01

    This conference was organized to study and analyze the role of simulation, analysis, modeling, and exercises in the history of NATO policy. The premise was not that the results of past studies will apply to future policy, but rather that understanding what influenced the decision process-and how-would be of value. The structure of the conference was built around discussion panels. The panels were augmented by a series of papers and presentations focusing on particular TNF events, issues, studies, or exercises. The conference proceedings consist of three volumes. Volume 1 contains the conference introduction, agenda, biographical sketches of principal participants, and analytical summary of the presentations and discussion panels. Volume 2 contains a short introduction and the papers and presentations from the conference. This volume contains selected papers by Brig. Gen. Robert C. Richardson III (Ret.).

  5. 'Creature' についての共時的・通時的考察 -Richardson の書簡体小説を中心として-

    OpenAIRE

    脇本, 恭子

    2008-01-01

    The present paper aims at examinig the word 'creature' from both synchronic and diachronic perspectives. The first section begins with providing several definitions of 'creature,' along with its etymology, in reference to such major dictionaries as the Oxford English Dictionary and Johnson's A Dictionary of the English Language(1755). In the subsequent three sections, the frequency and the collocation of this word are investigated through Richardson's Pamela and Clarissa as our main linguisti...

  6. Toxicity of smelter slag-contaminated sediments from Upper Lake Roosevelt and associated metals to early life stage White Sturgeon (Acipenser transmontanus Richardson, 1836)

    Science.gov (United States)

    Little, E.E.; Calfee, R.D.; Linder, G.

    2014-01-01

    The toxicity of five smelter slag-contaminated sediments from the upper Columbia River and metals associated with those slags (cadmium, copper, zinc) was evaluated in 96-h exposures of White Sturgeon (Acipenser transmontanus Richardson, 1836) at 8 and 30 days post-hatch. Leachates prepared from slag-contaminated sediments were evaluated for toxicity. Leachates yielded a maximum aqueous copper concentration of 11.8 μg L−1 observed in sediment collected at Dead Man's Eddy (DME), the sampling site nearest the smelter. All leachates were nonlethal to sturgeon that were 8 day post-hatch (dph), but leachates from three of the five sediments were toxic to fish that were 30 dph, suggesting that the latter life stage is highly vulnerable to metals exposure. Fish maintained consistent and prolonged contact with sediments and did not avoid contaminated sediments when provided a choice between contaminated and uncontaminated sediments. White Sturgeon also failed to avoid aqueous copper (1.5–20 μg L−1). In water-only 96-h exposures of 35 dph sturgeon with the three metals, similar toxicity was observed during exposure to water spiked with copper alone and in combination with cadmium and zinc. Cadmium ranging from 3.2 to 41 μg L−1 or zinc ranging from 21 to 275 μg L−1 was not lethal, but induced adverse behavioral changes including a loss of equilibrium. These results suggest that metals associated with smelter slags may pose an increased exposure risk to early life stage sturgeon if fish occupy areas contaminated by slags.

  7. Fine structure of the retinal pigment epithelium and cones of Antarctic fish Notohenia coriiceps Richardson in light and dark-conditions Ultraestrutra do epitélio pigmentar da retina e dos cones do peixe Antártico Notothenia coriiceps Richardson submetido à luz e ao escuro

    Directory of Open Access Journals (Sweden)

    Lucélia Donatti

    2007-03-01

    Full Text Available The Antarctic fish Notothenia coriiceps Richardson, 1844 lives in an environment of daily and annual photic variation and retina cells have to adjust morphologically to environmental luminosity. After seven day dark or seven day light acclimation of two groups of fish, retinas were extracted and processed for light and transmission electron microscopy. In seven day dark adapted, retina pigment epithelium melanin granules were aggregated at the basal region of cells, and macrophages were seen adjacent to the apical microvilli, between the photoreceptors. In seven day light adapted epithelium, melanin granules were inside the apical microvilli of epithelial cells and macrophages were absent. The supranuclear region of cones adapted to seven day light had less electron dense cytoplasm, and an endoplasmic reticulum with broad tubules. The mitochondria in the internal segment of cones adapted to seven day light were larger, and less electron dense. The differences in the morphology of cones and pigment epithelial cells indicate that N. coriiceps has retinal structural adjustments presumably optimizing vision in different light conditions.O peixe Antártico Notothenia coriiceps Richardson, 1844 habita meios com variações fóticas diária e anual e as células da retina se adaptam morfologicamente a esta luminosidade ambiental. Dois grupos de peixes foram aclimatados durante sete dias à luz constante ou ao escuro constante. Após secção medular, as retinas foram extraídas e processadas para microscopia de luz e microscopia eletrônica de transmissão. No epitélio pigmentar da retina adaptado sete dias ao escuro, os pigmentos de melanina agregam-se na base coroidal das células epiteliais pigmentares e macrófagos são encontrados no interior do processos apicais entre as células fotorreceptoras. No epitélio adaptado sete dias à luz os pigmentos de melanina se dispõem ao longo das projeções apicais das células epiteliais pigmentares e os

  8. Richardson constant and electrostatics in transfer-free CVD grown few-layer MoS2/graphene barristor with Schottky barrier modulation >0.6eV

    Science.gov (United States)

    Jahangir, Ifat; Uddin, M. Ahsan; Singh, Amol K.; Koley, Goutam; Chandrashekhar, M. V. S.

    2017-10-01

    We demonstrate a large area MoS2/graphene barristor, using a transfer-free method for producing 3-5 monolayer (ML) thick MoS2. The gate-controlled diodes show good rectification, with an ON/OFF ratio of ˜103. The temperature dependent back-gated study reveals Richardson's coefficient to be 80.3 ± 18.4 A/cm2/K and a mean electron effective mass of (0.66 ± 0.15)m0. Capacitance and current based measurements show the effective barrier height to vary over a large range of 0.24-0.91 eV due to incomplete field screening through the thin MoS2. Finally, we show that this barristor shows significant visible photoresponse, scaling with the Schottky barrier height. A response time of ˜10 s suggests that photoconductive gain is present in this device, resulting in high external quantum efficiency.

  9. Richardson extrapolation practical aspects and applications

    CERN Document Server

    Zlatev, Zahari; Faragó, István; Havasi, Ágnes

    2017-01-01

    The series is devoted to the publication of high-level monographs and specialized graduate texts which cover the whole spectrum of applied mathematics, including its numerical aspects. The focus of the series is on the interplay between mathematical and numerical analysis, and also on its applications to mathematical models in the physical and life sciences.

  10. 08 Richardson - On-farm demonstrations - gereed vir publik…

    African Journals Online (AJOL)

    lynette

    regular face-to-face exchanges and feedback, these were accomplished through e-mail .... evidence that such time consuming methods such as on-farm tests and field ... adopting new farm management practices, personal communication was.

  11. Bethe ansatz approach to quench dynamics in the Richardson model

    NARCIS (Netherlands)

    Faribault, A.D.P.; Calabrese, P.; Caux, J.S.

    2009-01-01

    By instantaneously changing a global parameter in an extended quantum system, an initially equilibrated state will afterwards undergo a complex nonequilibrium unitary evolution whose description is extremely challenging. A nonperturbative method giving a controlled error in the long time limit

  12. Residual, restarting and Richardson iteration for the matrix exponential

    NARCIS (Netherlands)

    Bochev, Mikhail A.; Grimm, Volker; Hochbruck, Marlis

    2013-01-01

    A well-known problem in computing some matrix functions iteratively is the lack of a clear, commonly accepted residual notion. An important matrix function for which this is the case is the matrix exponential. Suppose the matrix exponential of a given matrix times a given vector has to be computed.

  13. Residual, restarting and Richardson iteration for the matrix exponential

    NARCIS (Netherlands)

    Bochev, Mikhail A.

    2010-01-01

    A well-known problem in computing some matrix functions iteratively is a lack of a clear, commonly accepted residual notion. An important matrix function for which this is the case is the matrix exponential. Assume, the matrix exponential of a given matrix times a given vector has to be computed. We

  14. Summary of remarks by R.C. Richardson: NATO's basic TNF problem and principal posture findings

    International Nuclear Information System (INIS)

    Richardson, R.C.

    1994-01-01

    The use of atomic weapons in NATO defense planning seems to be an issue of special interest to writers and historians. It is also an issue fraught with confusion for the official record of actions taken does not tell the whole story. Both writers and historians seem to be having a hard time getting a clear and agreed position on this subject and for good reasons. Reasons which are not generally understood although important not only to history but also to future U.S. security planning. The confusion over tactical nuclear planning in NATO can be traced to the early 1950s when the Alliance was faced with the need to develop and present a credible defense posture for its European members while being unable to field classic force levels anywhere near comparable to those of the Warsaw Pact nations that threatened them. A summary paper is presented in two parts. Part I explains what the Basic TNF Problem appears to be and how it came about and Part II discusses examples of the type of corrective measures that should have been - and still should be - taken

  15. F-22 Plus-Up Environmental Assessment Joint Base Elmendorf-Richardson, Alaska

    Science.gov (United States)

    2011-06-01

    personnel and no new construction would be expected to result in no measurable effect upon the regional economy. The Anchorage housing market with...of JBER. The base adopted a General Plan in April 2005 that presents a comprehensive planning strategy to support military missions assigned to the...Recreation Area Wild and Scenic River 4p .- oil D5 cllitt0-·2=0 ::::::130---IOMiles • • • o s m w JO -10 i.:i.::ii.-IIIIE=~-- Naulica ll\\1i les F

  16. GIS-based rapid-assessment of bighead carp Hypophthalmichthys nobilis (Richardson, 1845) suitability in reservoirs

    Science.gov (United States)

    Long, James M.; Liang, Yu; Shoup, Daniel E.; Dzialowski, Andrew R.; Bidwell, Joseph R.

    2014-01-01

    Broad-scale niche models are good for examining the potential for invasive species occurrences, but can fall short in providing managers with site-specific locations for monitoring. Using Oklahoma as an example, where invasive bighead carp (Hypophthalmichthys nobilis) are established in certain reservoirs, but predicted to be widely distributed based on broad-scale niche models, we cast bighead carp reproductive ecology in a site-specific geospatial framework to determine their potential establishment in additional reservoirs. Because bighead carp require large, long free-flowing rivers with suitable hydrology for reproduction but can persist in reservoirs, we considered reservoir tributaries with mean annual daily discharge ≥8.5 cubic meters per second (m3 /s) and quantified the length of their unimpeded portions. In contrast to published broad-scale niche models that identified nearly the entire state as susceptible to invasion, our site-specific models showed that few reservoirs in Oklahoma (N = 9) were suitable for bighead carp establishment. Moreover, this method was rapid and identified sites that could be prioritized for increased study or scrutiny. Our results highlight the importance of considering the environmental characteristics of individual sites, which is often the level at which management efforts are implemented when assessing susceptibility to invasion.

  17. Effects of phenol on ATPase activities in crude gill homogenates of rainbow trout (Salmo gairdneri Richardson)

    Energy Technology Data Exchange (ETDEWEB)

    Poston, T.M.

    1979-01-01

    The ATPase specific activities from crude gill homogenates of rainbow trout were lower than those from microsomal preparations reported in the literature. Sodium pump activity (ouabain sensitive NaK-ATPase) was demonstrable at 37/sup 0/C. An ouabain insensitive NaK-ATPase was demonstrable at temperatures below 30/sup 0/C and may represent a Na-ATPase activity reported by others. Energy of activation at 25/sup 0/C for total NaK-ATPase ws 10,500 cal.mole/sup -1/. Mg-baseline activity had an energy of activation at 25/sup 0/C of 15,600 cal.mole/sup -1/. Mg-baseline activity was thermally labile at temperatures in excess of 30/sup 0/C. Concentrations of Mg/sup +2/ in excess of 5 mM appeared to inhibit total NaK-ATPase activity. At 37/sup 0/C, Na/sup +/ and K/sup +/ exerted little, if any, stimulatory effect on ATPase activities, in spite of the fact that 37/sup 0/C was the only temperature at which sodium pump activity was demonstrable. MS-222 failed to produce any discernible changes in any of the demonstrable ATPase activities in crude gill homogenates. Total NaK-ATPase activities were more sensitive than Mg-baseline activities to in vitro inhibition by phenol. Concentrations of phenol which produce 50% inhibition in total NaK-ATPase produced only 35% inhibition in Mg-baseline activity. The nature of in vitro inhibition was uncompetitive. Sodium pump activity was unaffected by phenol at concentrations as high as 25 mM. An effort was made to demonstrate an in vivo effects of phenol on rainbow trout gill ATPase activites. An infestation of a parasite (Gyrodactilus) on the experimental fish precludes any definative assessment of in vivo effects.

  18. Water Conservation Study. U.S. Army Alaska (USARAK) Fort Richardson, Alaska

    National Research Council Canada - National Science Library

    1995-01-01

    .... The purpose of this water conservation study is to conduct a limited site survey and evaluate energy use and savings, estimate construction costs and water savings and provide a cost-to-savings ratio...

  19. Water Conservation Study, U.S. Army Alaska (USARAK), Ft. Richardson, Alaska

    National Research Council Canada - National Science Library

    1995-01-01

    The purpose of this water conservation study is to conduct a limited site survey and evaluate energy use and savings, estimate construction costs and water savings and provide a cost-to-savings ratio...

  20. Natural growth, otolith shape and diet analyses of Odontesthes nigricans Richardson (Atherinopsidae) from southern Patagonia

    Science.gov (United States)

    Lattuca, M. E.; Lozano, I. E.; Brown, D. R.; Renzi, M.; Luizon, C. A.

    2015-12-01

    Age and growth, otolith shape and diet of Odontesthes nigricans were analysed in order to provide an insight into the life history of the species and furthermore, to assess their possible use as a tool for discriminating silverside populations from the South Atlantic Ocean (Punta María) and Beagle Channel waters (Varela Bay). The age and growth analysis was performed by counting daily increments and annual marks in sagittae otoliths. Length-at-age data of individuals Otolith shape variation was also explored using elliptical Fourier analysis and it showed significant differences between Varela Bay and Punta María populations. Furthermore, gut content analysis characterized O. nigricans as an invertebrate predator, being benthic organisms the most important components of its diet, which also showed significant site dependence. The use of all these analyses contributed to a holistic approach which maximized the likelihood of correctly identifying both O. nigricans populations in the southernmost limit of the species distribution.

  1. Grady Highway Extension (Ship Creek Crossing) Elmendorf Air Force Base and Fort Richardson, Alaska

    Science.gov (United States)

    2005-06-01

    appear to have developed in depressions and floodplain channels where water is either shallow or exposed to the surface during periods of high water...Emergent, Persistent, Seasonally Flooded). A narrow depressional area with exposed water demonstration flow characteristics of the hyporheic zone...hyporheic zone. Dominant vegetation includes thin-leaf alder, cottonwood, lady fern, highbush cranberry , tuberous spring beauty and marsh

  2. Remediating and Monitoring White Phosphorus Contamination at Eagle River Flats (Operable Unit C), Fort Richardson, Alaska

    National Research Council Canada - National Science Library

    Walsh, M. E; Racine, C. H; Collins, C. M; Walsh, M. R; Bailey, R. N

    2001-01-01

    .... Army Engineer District, Alaska, and U.S. Army Alaska, Public Works, describing the results of research, monitoring, and remediation efforts addressing the white phosphorus contamination in Eagle River Flats, an 865-ha estuarine salt marsh...

  3. Complete mitochondrial genome sequence of the Barbour's seahorse Hippocampus barbouri Jordan & Richardson, 1908 (Gasterosteiformes: Syngnathidae).

    Science.gov (United States)

    Wang, Bo; Zhang, Yanhong; Zhang, Huixian; Lin, Qiang

    2015-01-01

    The complete mitochondrial genome sequence of the Barbour's seahorse Hippocampus barbouri was first determined in this paper. The total length of H. barbouri mitogenome is 16,526 bp, which consists of 13 protein-coding genes, 22 tRNA and 2 rRNA genes and 1 control region. The features of the H. barbouri mitochondrial genome were similar to the typical vertebrates. The overall base composition of H. barbouri is 32.68% A, 29.75% T, 22.91% C and 14.66% G, with an AT content of 62.43%.

  4. Some factors affecting the resistance of rainbow trout (Salmo gairdnerii richardson) to acid waters

    Energy Technology Data Exchange (ETDEWEB)

    Lloyd, R; Jordan, D H.M.

    1964-01-01

    The pH value at which acid solutions proved lethal to rainbow trout within 1 day was unaffected by the pH value to which the fish had been acclimatized. In waters of total hardness 320, 40, and 12 ppM as CaCO/sub 3/, 50 percent of the fish died in 4 days at pH values of 4.18, 4.22, and 4.25 respectively. The relation between log survival time and pH value, up to pH 3.95 at which the median period of survival is 34 hr, is substantially linear and is unaffected by the presence of up to 50 ppM free carbon dioxide. Although at higher pH values this linear relation is maintained in the presence of 1.5 ppM (and possibly of up to 10 ppM) free carbon dioxide, at higher concentrations the survival time was progressively diminished by up to 50 ppM free carbon dioxide. Extrapolation of the results suggests that exposure to pH values below 5.0 for about 3 months might be harmful to rainbow trout when little free carbon dioxide was present in the water, but if an acid discharge were to rinse the free carbon dioxide content to 20 ppM, mortalities might occur within about 3 months when the ph value of the water fell below 6.0. Comparisons of the pH value and total carbon dioxide content of the blood of rainbow trout killed in acid solutions with those of control fish suggested that death was due to acidaemia.

  5. On relative spatial diffusion in plasma and fluid turbulences: clumps, Richardson's law and intrinsic stochasticity

    International Nuclear Information System (INIS)

    Misguich, J.H.; Balescu, R.

    1981-02-01

    Three different time regimes are presented for relative spatial diffusion of charged particles in fluctuating electric fields, which behave like tau 3 , exp (tau) and tau 3 , respectively. The first regime, corresponding to a quasi-linear description of the trajectories, is analogous to the one observed in fluid turbulence and is valid in the limit of a small amplitude turbulent spectrum, or for not too small initial separation of the particles. The third regime, appearing for long times, describes the diffusion of independent particles at very large separations. Its existence is ensured by the nonlinear renormalization of the propagators. The second, intermediate, regime appears in a stochastic treatment of the renormalization effect for particles with a very small spatial and velocity difference, and describes Dupree's clumps diffusion. The appearance of the corresponding regime is similar to that of the Suzuki scaling regime of non-linear Langevin equations. It is also shown that the clumps have a behaviour similar to an intrinsic stochasticity, but which is of extrinsic nature. Similar failure of the quasi-linear approximation for spacific velocity domains has been previously studied and solved for classical Landau collisions, as well as for pitch angle diffusion where renormalization effects have been proved also to be important

  6. Book Review: Lobbying the European Union: Institutions, Actors and Issues, David Coen and Jeremy Richardson (eds.

    Directory of Open Access Journals (Sweden)

    Alexandra Pop

    2013-03-01

    Full Text Available The volume "Lobbying the European Union: Institutions, Actors and Issues", collects 16 articles on interest group politics at EU level, focusing on the main elements of European lobbying - the existing relations between the EU institutions and the special interests, the main differences between NGO and business lobbying, the specific lobbying strategies adopted in EU's main policy sectors or lobbying regulations. The volume captures the main changes that took place on the European lobbying scene in the last two decades, period in which most EU institutions developed new points of access for lobbyists, while the interest groups became more specialized. The success of an EU lobbying campaign seems to be determined by a combination of various factors such as: a good knowledge of the EU environment, a wise usage of both financial resources and expertise, direct lobbying complemented by an efficient usage of domestic routes and the capability of creating smart alliances.

  7. 75 FR 67618 - Safety Zone: Richardson Ash Scattering by Fireworks, San Francisco, CA

    Science.gov (United States)

    2010-11-03

    ... fireworks display is meant for entertainment purposes. This safety zone is issued to establish a temporary... under Executive Order 13211. Technical Standards The National Technology Transfer and Advancement Act..., disestablishing, or changing Regulated Navigation Areas and security or safety zones. An environmental analysis...

  8. Teachers' perceptions of resistant behaviour of children in the middle childhood developmental phase / Nicola Taryn Richardson

    OpenAIRE

    Richardson, Nicola Taryn

    2014-01-01

    Resistant behaviour is a serious reality in South African primary schools. South Africa’s teachers strive to be agents of positive change amidst the multiple challenges they and their learners encounter, yet they admittedly experience daily frustration at addressing resistant behaviour. Considering the harsh external realities which many learners encounter, resistant behaviour cannot be expected to disappear at the introduction of specific techniques. The research consequently aimed to examin...

  9. Environmental Assessment for Watershed Enhancements at Joint Base Elmendorf-Richardson

    Science.gov (United States)

    2013-07-03

    and disposed at the Anchorage Regional Landfill . Dead fish observed after break-up in the spring will again be collected and disposed. Rotenone...Trout Stocking: A Literature Review with Special Reference to Washington Department of Game’s Lake Rehabilitation Program. Fisheries Management Report...office, Anchorage, Alaska. Davis, R. 1973. Report on the Rehabilitation of Otter Lake. October 15. Elmendorf Aero Club. 2010. Standard Operating

  10. Environmental Assessment for Wildland Fire Prevention Activities at Joint-Base Elmendorf-Richardson (JBER), Alaska

    Science.gov (United States)

    2015-04-01

    clay or dry sand. Report large spills to Dow AgroSciences at 800-992- 5994. 11. HANDLING AND STORAGE: PRECAUTIONS TO BE TAKEN IN HANDLING AND STORAGE...Methods for Containment: Dike spill using absorbent or impervious materials such as earth, sand or clay . Collect and contain contaminated absorbent and...Not determined Freezing Point: Not determined Vapor Pressure: Not determined pH: 3.3 (1% solution) Viscosity : Not determined Note: Physical data

  11. Evaluation of precut transverse cracks for an asphalt concrete pavement in interior Alaska (Moose Creek - Richardson Highway).

    Science.gov (United States)

    2015-08-01

    Road-width thermal cracks (major transverse cracks) are perhaps the most noticeable form of crack-related damage on AC pavements : throughout colder areas of Alaska. The main objective of this study is to recommend design strategies and construction ...

  12. Status of White Sturgeon (Acipenser transmontanus Richardson, 1863) throughout the species range, threats to survival, and prognosis for the future

    Science.gov (United States)

    Hildebrand, L. R.; Drauch Schreier, Andrea; Lepla, K.; McAdam, S. O.; McLellan, J; Parsley, Michael J.; Paragamian, V L; Young, S P

    2016-01-01

    White Sturgeon, Acipenser transmontanus (WS), are distributed throughout three major river basins on the West Coast of North America: the Sacramento-San Joaquin, Columbia, and Fraser River drainages. Considered the largest North American freshwater fish, some WS use estuarine habitat and make limited marine movements between river basins. Some populations are listed by the United States or Canada as threatened or endangered (upper Columbia River above Grand Coulee Dam; Kootenai River; lower, middle and, upper Fraser River and Nechako River), while others do not warrant federal listing at this time (Sacramento-San Joaquin Rivers; Columbia River below Grand Coulee Dam; Snake River). Threats that impact WS throughout the species’ range include fishing effects and habitat alteration and degradation. Several populations suffer from recruitment limitations or collapse due to high early life mortality associated with these threats. Efforts to preserve WS populations include annual monitoring, harvest restrictions, habitat restoration, and conservation aquaculture. This paper provides a review of current knowledge on WS life history, ecology, physiology, behavior, and genetics and presents the status of WS in each drainage. Ongoing management and conservation efforts and additional research needs are identified to address present and future risks to the species.

  13. Sampling and Mapping Soil Erosion Cover Factor for Fort Richardson, Alaska. Integrating Stratification and an Up-Scaling Method

    National Research Council Canada - National Science Library

    Wang, Guangxing; Gertner, George; Anderson, Alan B; Howard, Heidi

    2006-01-01

    When a ground and vegetation cover factor related to soil erosion is mapped with the aid of remotely sensed data, a cost-efficient sample design to collect ground data and obtain an accurate map is required...

  14. Analysis of an Hertwig effect in the rainbow trout (Salmo gairdneri Richardson) after fertilization with γ-irradiated sperm

    International Nuclear Information System (INIS)

    Chourrout, D.; Chevassus, B.; Herioux, F.

    1980-01-01

    In this work, we tried to optimize γ-treatment of sperm to obtain large numbers of haploid gynogenetic embryos after fertilization. The analysis of increasing doses showed a typical 'Hertwig effect' in all cases, but we found wide between-male variations in the most efficient dose. This variability was reduced by mixing several irradiated samples collected from different males or given different efficient doses

  15. Florence Richardson Wyckoff (1905-1997), Fifty Years of Grassroots Social ActivismVolume III: Watsonville Years 1960-1985

    OpenAIRE

    Wyckoff, Florence Richardson; Jarrell, Randall

    1990-01-01

    Florence Wyckoff's three-volume oral history documents her remarkable, lifelong work as a social activist, during which she has become nationally recognized as an advocate of migrant families and children. From the depression years through the 1970s, she pursued grassroots, democratic, community-building efforts in the service of improving public health standards and providing health care, education, and housing for migrant families. Major legislative milestones in her career of advocacy were...

  16. Relating river discharge and water temperature to the recruitment of age‐0 White Sturgeon (Acipenser transmontanus Richardson, 1836) in the Columbia River using over‐dispersed catch data

    Science.gov (United States)

    Counihan, Timothy D.; Chapman, Colin G.

    2018-01-01

    The goals were to (i) determine if river discharge and water temperature during various early life history stages were predictors of age‐0 White Sturgeon, Acipenser transmontanus, recruitment, and (ii) provide an example of how over‐dispersed catch data, including data with many zero observations, can be used to better understand the effects of regulated rivers on the productivity of depressed sturgeon populations. An information theoretic approach was used to develop and select negative binomial and zero‐inflated negative binomial models that model the relation of age‐0 White Sturgeon survey data from three contiguous Columbia River reservoirs to river discharge and water temperature during spawning, egg incubation, larval, and post‐larval phases. Age‐0 White Sturgeon were collected with small mesh gill nets in The Dalles and John Day reservoirs from 1997 to 2014 and a bottom trawl in Bonneville Reservoir from 1989 to 2006. Results suggest that seasonal river discharge was positively correlated with age‐0 recruitment; notably that discharge, 16 June–31 July was positively correlated to age‐0 recruitment in all three reservoirs. The best approximating models for two of the three reservoirs also suggest that seasonal water temperature may be a determinant of age‐0 recruitment. Our research demonstrates how over‐dispersed catch data can be used to better understand the effects of environmental conditions on sturgeon populations caused by the construction and operation of dams.

  17. Mining pollution and the diet of the purple-striped Gudgeon Mogurnda Mogurnda Richardson (Eleotridae) in the Finniss River, Northern Territory, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Jeffree, R.A.; Williams, N.J.

    1980-01-01

    During the dry season of 1974, collections of the purple-striped Gudgeon Mogurnda Mogurnda were taken from the Finniss River of the Northern Territory; during the wet season, this river receives acidic and metallic pollutants from the formerly mined area of Rum Jungle. The fish consumed a great variety of foods, with high abundances of dytiscidae, chironomidae, ceratopogonidae, trichoptera, odonata, copepoda, decapoda, and pisces. For no food was there a significant regression against habitat descriptors in both of the zones; this emphasizes that pollution effects are more complex than simply depressing or raising the abundances of the dietary species. Five foods were more abundant in the diets of the polluted zone, and three in those of the unpolluted zone. The dietary abundances of two foods, both crustacean, increased in the polluted zone, compared to the unpolluted zone, through the dry season. Two categories of foods: (1) those obtaining oxygen directly from the atmosphere or via a film or bubble of air; and (2) the converse set (aquatic respirers), were contrasted for their usefulness in distinguishing between the zones, by both hierarchical agglomerative and discriminant function analyses. One collection from the polluted zone was reclassified as unpolluted on the basis of its grouping behaviour. The relevance for pollution studies of dietary analysis of euryphagous fish, rather than sampling aquatic fauna directly, is discussed in terms of food substitution, switching, strategies for abundance and recovery by the fauna, and possible effects of the pollutants on the fish as an intervening collector. Downstream patterns of abundance of the invertebrate fauna in this study are broadly similar to those of other studies in which such chemically diverse metals as Pb, Zn, and Cu are the pollutants, but there are differences for some faunal components.

  18. Investigation of Vibrio alginolyticus, V. harveyi, and V. parahaemolyticus in large yellow croaker, Pseudosciaena crocea (Richardson reared in Xiangshan Bay, China

    Directory of Open Access Journals (Sweden)

    Lu Liu

    2016-05-01

    Full Text Available Large yellow croaker (LYC, Pseudosciaena crocea is an economically important fish species of mariculture in China. The variation of yearly production of LYC has been increasingly related to the outbreaks of fish diseases. Moreover, Vibrio infections have been identified in this fish frequently. To understand the pattern of Vibrio infections in LYC, we conducted a culture-independent survey of Vibrios in farmed LYC populations using a multiplex PCR method targeting Vibrio alginolyticus, Vibrio harveyi and Vibrio parahaemolyticus. The results showed that three fish pathogenic Vibrios had been detected in LYC populations at each sampling with a prevalence ranging from 6.7% to 73.3% but no single species dominated the Vibrio infection. The findings indicate that three Vibrio species still have impact on health status of farmed LYC and LYC aquaculture requires more efficacious prophylactic strategies. Keywords: Vibrio, Large yellow croaker, Multiplex PCR, Epidemiology

  19. Investigation of Vibrio alginolyticus, V. harveyi, and V. parahaemolyticus in large yellow croaker, Pseudosciaena crocea (Richardson) reared in Xiangshan Bay, China

    OpenAIRE

    Lu Liu; Mingfeng Ge; Xiaoye Zheng; Zhen Tao; Suming Zhou; Guoliang Wang

    2016-01-01

    Large yellow croaker (LYC), Pseudosciaena crocea is an economically important fish species of mariculture in China. The variation of yearly production of LYC has been increasingly related to the outbreaks of fish diseases. Moreover, Vibrio infections have been identified in this fish frequently. To understand the pattern of Vibrio infections in LYC, we conducted a culture-independent survey of Vibrios in farmed LYC populations using a multiplex PCR method targeting Vibrio alginolyticus, Vibri...

  20. Age validation and growth of yolked larvae of Patagonotothen tessellata (Richardson, 1845 (Pisces: Nototheniidae from the rocky littoral of the Beagle Channel, Argentina

    Directory of Open Access Journals (Sweden)

    Gustavo Alfredo Rae

    1999-12-01

    Full Text Available Age and growth estimation of Patagonotothen tessellata larvae over the endogenous period was estimated by examining their otolith microstructure and the associated increment deposition rate. Analyzed specimens were incubated from egg-masses collected in Lapataia Bay, Beagle Channel, Argentina. Validation was performed by monitoring reared larvae of known ages. Actual age and increment count were regressed suggesting a daily deposition of one ring in the otolith, which began at hatching time and continued until larvae reached sixteen days old (time of massive mortality. Mean lengths at each age were estimated using Richards´ growth function; their constant (m attained a value close to zero indicating that the data fitted to the von Bertalanffy model. Absolute growth rate was 0.55 mm*d-1of total length at hatching, dropped near zero on the fifth day after hatching and afterwards, there was no growth. Yolk absorption rate (expressed as a ratio between minor axis/major axis of the vitelline-sac showed a similar variation as that observed in absolute growth rate during the endogenous period. The total yolk absorption took five days in the unfed larvae group and seven days in the fed larvae group. The rapid absorption of the yolk and the observed growth pattern suggest that Patagonotothen tessellata larvae have a short endogenous period, reaching the state of first food uptake five days after hatching.

  1. Interim Report on the Investigation of the Fresh Properties of Synthetic Fiber-Reinforced Concrete for the Richardson Landing Casting Field

    Science.gov (United States)

    2017-04-01

    ER D C/ G SL S R- 17 -1 Interim Report on the Investigation of the Fresh Properties of Synthetic Fiber - Reinforced Concrete for the...default. ERDC/GSL SR-17-1 April 2017 Interim Report on the Investigation of the Fresh Properties of Synthetic Fiber - Reinforced Concrete for... reinforced concrete mixtures containing 3-, 2-, and 1-lb(s)/yd3, respectively, of synthetic (polypropylene) fiber into the current mixture proportion

  2. Age estimations of wild pallid sturgeon (Scaphirhynchus albus, Forbes & Richardson 1905) based on pectoral fin spines, otoliths and bomb radiocarbon: inferences on recruitment in the dam-fragmented Missouri River

    Science.gov (United States)

    Braaten, P. J.; Campana, S. E.; Fuller, D. B.; Lott, R. D.; Bruch, R. M.; Jordan, G. R.

    2015-01-01

    An extant stock of wild pallid sturgeon Scaphirhynchus albus persists in the fragmented upper Missouri River basin of Montana and North Dakota. Although successful spawning and hatch of embryos has been verified, long-term catch records suggest that recruitment has not occurred for several decades as the extant stock lacks juvenile size classes and is comprised exclusively of large, presumably old individuals. Ages of 11 deceased (death years 1997–2007) wild S. albus (136–166 cm fork length) were estimated based on pectoral fin spines, sagittal otoliths and bomb radiocarbon (14C) assays of otoliths to test the hypothesis that members of this stock are old and to provide inferences on recruitment years that produced the extant stock. Age estimations based on counts of presumed annuli were about 2 years greater for otoliths (mean = 51 years, range = 43–57 years) than spines (mean = 49 years, range = 37–59 years). Based on 14C assays, confirmed birth years for all individuals occurred prior to 1957, thus establishing known longevity of at least 50 years. Estimated age based on presumed otolith annuli for one S. albus was validated to at least age 49. Although 14C assays confirmed pre-1957 birth years for all S. albus, only 56% of estimated ages from spines and 91% of estimated ages from otoliths depicted pre-1957 birth years. Both ageing structures were subject to under-ageing error (up to 15 years). Lack of or severe curtailment of S. albus recruitment in the upper Missouri River basin since the mid-1950s closely parallels the 1953–1957 timeframe when a mainstem reservoir was constructed and started to fill. This reservoir may function as a system-wide stressor to diminish recruitment success of S. albus in the upper Missouri River basin.

  3. 养殖大黄鱼病原弧菌多重PCR检测技术的建立和应用%Development and application of multiplex PCR of vibrios pathogenic to cultured large yellow croaker, Pseudnosciaena crocea (Richardson)

    Institute of Scientific and Technical Information of China (English)

    祝璟琳; 王国良; 金珊

    2009-01-01

    溶藻弧菌(Vibrio alginolyticus)、副溶血弧菌(vibrio parahaemolyticus)和哈维氏弧菌(Vibrio harveyi)是浙江省养殖大黄鱼(Pseudnosciaena crocea)弧菌病的主要致病菌.本研究选择针对溶藻弧菌和副溶血弧菌的胶原酶基因,哈维氏弧菌的部分ToxR基因的特异性,优化设计了3对特异性引物,通过进行多重PCR反应体系优化,多重PCR产物的测序鉴定与特异性和敏感性实验,建立了一种检测致病性弧菌的多重PCR检测方法.经过琼脂糖凝胶电泳后的条带分析判断,可以在一个PCR管中同时成功地检测这3种病原细菌,含溶藻弧菌、哈维氏弧菌和副溶血弧菌3种致病弧菌核酸的阳性对照样品分别扩增出大小为737 hp、382 bp和271 bp的预期产物,其灵敏度是102~102 CFU/mL.将该方法应用于检测人工感染后的养殖大黄鱼病鱼肝脏和肾脏,结果在6份组织样本中,5份检出原始感染菌株,与API 20E鉴定结果相符;对弧菌病流行季节采集的未发病的16份养殖大黄鱼组织样本和16份水体样本进行抽检,结果在1份大黄鱼组织样本中检出哈维氏弧菌,7份水体样本中检出这3种弧菌中的1种或2种,鉴定结果与API 20E鉴定结果符合率为93.75%.说明该方法不仅可以检测发病鱼,还可以检测无病症带菌大黄鱼以及带菌水样,且说明海洋水体中存在着大黄鱼弧菌病的致病菌.结果说明,多重PCR检测方法具有较高的敏感性与特异性,可以缩短检测时间,降低检测成本,该方法的建立对养殖大黄鱼弧菌病的快速诊断和分子流行病学的调查具有重要意义.

  4. Impacto do fluoreto na resposta metabólica do peixe antártico Notothenia Rossii (Richardson, 1844) aclimatado sob condições de estresse térmico e hiposmótico

    OpenAIRE

    Rodrigues Júnior, Édson

    2013-01-01

    Resumo: A Antártica é considerada a região mais preservada do planeta e apresenta características de um ambiente único. A extinção da antiga fauna antártica e o estabelecimento da atual ocorreu sob a pressão seletiva das baixas temperaturas. Durante o inverno austral, a baixa produtividade primária do ambiente marinho antártico restringe a disponibilidade de alimento na coluna d'água e a sua transferência para o sistema bentônico. A Península Antártica é uma das três regiões do planeta que so...

  5. 15 CFR Appendix B to Subpart G of... - Marine Reserve Boundaries

    Science.gov (United States)

    2010-01-01

    ....] B.1. Richardson Rock (San Miguel Island) Marine Reserve The Richardson Rock Marine Reserve (Richardson Rock) boundary is defined by the 3 nmi State boundary, the coordinates provided in Table B-1, and the following textual description. The Richardson Rock boundary extends from Point 1 to Point 2 along...

  6. Lessons from Embryos: Haeckel's Embryo Drawings, Evolution, and Secondary Biology Textbooks

    Science.gov (United States)

    Wellner, Karen L.

    2014-01-01

    In 1997, developmental biologist Michael Richardson compared his research team's embryo photographs to Ernst Haeckel's 1874 embryo drawings and called Haeckel's work "noncredible". "Science" soon published "Haeckel's Embryos: Fraud Rediscovered," and Richardson's comments further reinvigorated criticism of Haeckel by…

  7. A prototype of behavior selection mechanism based on emotion

    Science.gov (United States)

    Zhang, Guofeng; Li, Zushu

    2007-12-01

    In bionic methodology rather than in design methodology more familiar with, summarizing the psychological researches of emotion, we propose the biologic mechanism of emotion, emotion selection role in creature evolution and a anima framework including emotion similar to the classical control structure; and consulting Prospect Theory, build an Emotion Characteristic Functions(ECF) that computer emotion; two more emotion theories are added to them that higher emotion is preferred and middle emotion makes brain run more efficiently, emotional behavior mechanism comes into being. A simulation of proposed mechanism are designed and carried out on Alife Swarm software platform. In this simulation, a virtual grassland ecosystem is achieved where there are two kinds of artificial animals: herbivore and preyer. These artificial animals execute four types of behavior: wandering, escaping, finding food, finding sex partner in their lives. According the theories of animal ethnology, escaping from preyer is prior to other behaviors for its existence, finding food is secondly important behavior, rating is third one and wandering is last behavior. In keeping this behavior order, based on our behavior characteristic function theory, the specific functions of emotion computing are built of artificial autonomous animals. The result of simulation confirms the behavior selection mechanism.

  8. Notas sobre predação em uma taxocenose de anfíbios anuros no sudeste do Brasil Predation notes in an anuran amphibians assemblage from southeastern Brazil

    Directory of Open Access Journals (Sweden)

    José P. Pombal Jr

    2007-01-01

    Full Text Available Anfíbios anuros são predados por todos os grupos de vertebrados e muitos invertebrados. Todavia os estudos sobre predação em anfíbios anuros ainda são esparsos e anedóticos. Neste estudo são fornecidas informações sobre predação de anuros de uma assembléia no sudeste do Brasil. Invertebrados (aranhas e barata d’agua, a rã Leptodactylus cf. ocellatus e cinco espécies serpentes (quatro Colubridae e um Viperidae predaram espécies ou indivíduos de pequeno porte.Anuran amphibians are preyer by all vertebrate groups and several invertebrates. However, predation studies on amphibians are still occasional and anecdotic. Herein, informations on predation of an anuran assemblage of southeastern Brazil are provided. Invertebrates (spiders and water bugs, the frog Leptodactylus cf. ocellatus, and five snake species (four Colubridae and one Viperidae preyer on small individuals or small anuran species.

  9. Denarration in Michael Haneke’s funny FUNNY games GAMES [an audiovisual essay

    NARCIS (Netherlands)

    Kiss, Miklós

    2016-01-01

    In literary fiction, Brian Richardson has discerned a troubling kind of incongruity that he labelled denarration. Denarration is “an intriguing and paradoxical narrative strategy that appears in a number of late modern and postmodern texts” (Richardson 2001, 168). Richardson coins the term for cases

  10. Fundamentals of Filament Interaction

    Science.gov (United States)

    2017-05-19

    AFRL-AFOSR-VA-TR-2017-0110 FUNDAMENTALS OF FILAMENT INTERACTION Martin Richardson UNIVERSITY OF CENTRAL FLORIDA Final Report 06/02/2017 DISTRIBUTION...of Filament Interaction 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA95501110001 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Martin Richardson 5d. PROJECT...NAME OF RESPONSIBLE PERSON Martin Richardson a. REPORT b. ABSTRACT c. THIS PAGE 19b. TELEPHONE NUMBER (Include area code) 407-823-6819 Standard Form

  11. 75 FR 22873 - Nebraska Disaster # NE-00035

    Science.gov (United States)

    2010-04-30

    ..., Madison, Nance, Nemaha, Nuckolls, Otoe, Pawnee, Pierce, Platte, Polk, Richardson, Saline, Seward, Stanton... of Federal Domestic Assistance Numbers 59002 and 59008) James E. Rivera, Associate Administrator for...

  12. Equivariant quantum Schubert calculus

    OpenAIRE

    Mihalcea, Leonardo Constantin

    2006-01-01

    We study the T-equivariant quantum cohomology of the Grassmannian. We prove the vanishing of a certain class of equivariant quantum Littlewood-Richardson coefficients, which implies an equivariant quantum Pieri rule. As in the equivariant case, this implies an algorithm to compute the equivariant quantum Littlewood-Richardson coefficients.

  13. Nisin Migration in Shelf Stable, Tuna-Filled Tortillas During Storage

    Science.gov (United States)

    2014-09-22

    INGREDIENTS AND PROCESSING ..........................................................................4 2.4 TUNA WRAP STORAGE...Leung, 1986 and Taub, 2003), meat (Pavey, 1972; Powers, 1981; Yang, 1997 and Richardson, 1995), seafood (Dymsza, 1979), eggs (Richardson, 2008 and...Incorporation of Preservatives, such as nitrites and antioxidants. (4) Thermal pasteurization by baking. (5) Appropriate Packaging, such as the

  14. “Pinning strategy”: a novel approach for predicting the backbone ...

    Indian Academy of Sciences (India)

    Prakash

    To assess the quality of the strategy, we define two measures. The first one ...... modular framework of the protein backbone; Protein Eng. 12. 1063–1073 .... Richardson J S, Getzoff E D and Richardson D C 1978 The beta bulge: a common ...

  15. Analysis of stability parameters in relation to precipitation associated ...

    Indian Academy of Sciences (India)

    erty and crops; human and animal fatalities, and also aviation hazards. ... Keywords. Atmospheric instability; stability indices; Richardson number; vertical wind shear; energy-helicity index; ... ing the genesis and development of severe weather.

  16. 77 FR 59014 - Investigations Regarding Eligibility To Apply for Worker Adjustment Assistance

    Science.gov (United States)

    2012-09-25

    ... Exide Technologies Bristol, TN........ 09/10/12 09/07/12 (Company). 81957 Edmund Optics, Inc. Pennsburg...'' (Workers). 81962 Verizon Business Richardson, TX..... 09/11/12 09/10/12 (Workers). 81963 Eco Energy...

  17. 76 FR 45867 - Michael S. Moore, M.D.; Suspension of Registration

    Science.gov (United States)

    2011-08-01

    ... findings in his area of competence. * * *'' 402 U.S. 389, 402 (1971). As the post-Richardson cases have... combination of factors may be relied upon, and when exercising authority as an impartial adjudicator, the...

  18. Trigonella foenum-graecum L.

    African Journals Online (AJOL)

    Jane

    2010-10-18

    . ... used for making oily pickles in South Asia. Galactagogue ... weeks of culture, more than 1 cm long regenerated shoots were taken and ..... Huetteman SE, Schotz AH, Wardley-Richardson T, Spencer D, Higgins. TJV (1993).

  19. Tavaline roomlane / Aare Ermel

    Index Scriptorium Estoniae

    Ermel, Aare, 1957-2013

    2007-01-01

    Iiri päritolu näitleja Ray Richardson, kes kehastab ajaloolises teleseriaalis "Rooma" (tootjad Ameerika HBO, inglaste BBC ja itaallaste RAI) Gaius Julius Caesari sõdurit Titus Pullot. Sama : Teleleht nr. 1, lk. 14 : ill

  20. Tunnelling Effects in Chemistry

    Indian Academy of Sciences (India)

    IAS Admin

    For example, whether two molecules A and B will spon- taneously react to ... For example, in the process of respiration, carbohydrate ... This means that they are governed ..... T H Lowry and K S Richardson, Mechanism and Theory in Organic.

  1. Towards an optimal model for a bistable nematic liquid crystal display device

    KAUST Repository

    Cummings, L. J.; Cai, C.; Kondic, L.

    2013-01-01

    and Richardson (Euro J Appl Math 17:435-463 2006), and explore means by which it may be optimized, in terms of optical contrast, manufacturing considerations, switching field strength, and switching times. The compromises inherent in these conflicting design

  2. Breeding biology of the bush veld gerbil Tatera leucogaster in ...

    African Journals Online (AJOL)

    1987-03-27

    Mar 27, 1987 ... A detailed account of age determination and population age struc- ture of T. ..... rabbit in Western Australia (Gooding & Long 1957). It appears that the .... duction and growth in laboratory rats is 16%, whereas. Richardson et al.

  3. Discovery of superfluid 3He phases wins 1996 nobel prize in physics

    International Nuclear Information System (INIS)

    Yan Shousheng

    1997-01-01

    The 1996 Nobel prize in physics was awarded to David M. Lee, Douglas D. Osheroff and Robert C. Richardson for their discovery of superfluidity in 3 He in 1971. A short account of the discovery and its importance is given

  4. 342 Effects of Improvised Materials on Students' Achievement and ...

    African Journals Online (AJOL)

    FIRST LADY

    2011-01-18

    Jan 18, 2011 ... Richardson formula 20 and a reliability index of 0.78 was obtained. Theory. The improvised ... removed and stored in a separate container. .... group taught with improvised material achieved higher than the control group.

  5. 50 CFR 660.383 - Open access fishery management measures.

    Science.gov (United States)

    2010-10-01

    .... south to the U.S./Mexico border) is permitted within the non-trawl RCA with fixed gear only under the..., President Jackson Seamount, Cordell Bank (50-fm (91-m) isobath), Harris Point, Richardson Rock, Scorpion...

  6. 77 FR 44583 - Takes of Marine Mammals Incidental to Specified Activities; Piling and Fill Removal in Woodard...

    Science.gov (United States)

    2012-07-30

    ... frequency range of 100-1,000 Hz (Richardson et al., 1995). Pups make individually unique calls for mother... hearing loss caused by fatigue of hair cells and supporting structures in the inner ear, is the mildest...

  7. 76 FR 56172 - Takes of Marine Mammals Incidental to Specified Activities; Piling and Structure Removal in...

    Science.gov (United States)

    2011-09-12

    ... frequency range of 100-1,000 Hz (Richardson et al., 1995). Pups make individually unique calls for mother... cells and supporting structures in the inner ear, is the mildest form of hearing impairment that can...

  8. Prevent Infections During Chemotherapy

    Centers for Disease Control (CDC) Podcasts

    This podcast discusses the importance of preventing infections in cancer patients who are undergoing chemotherapy. Dr. Lisa Richardson, CDC oncologist, talks about a new Web site for cancer patients and their caregivers.

  9. Analysis of stability parameters in relation to precipitation associated

    Indian Academy of Sciences (India)

    Atmospheric instability; stability indices; Richardson number; vertical wind ... is used to compute some important dynamic/thermodynamic parameters and are ... (i*) well indicate the occurrence of thunderstorms about 2 hours in advance.

  10. Lead adsorption study on combustion derived γ-Fe2O3 surface

    Indian Academy of Sciences (India)

    Administrator

    of a suitable economic fuel, our use of polyvinyl alcohol has given promising ... Mallikarjuna et al 2003) and ground well in a pestle and mortar. The resultant .... Kinsman S 1978 Systematic materials analysis (eds) T H. Richardson and R V ...

  11. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    POC) in the Northeastern Gulf of Mexico · Young Baek Son Wilford D Gardner Alexey V Mishonov Mary Jo Richardson · More Details Abstract Fulltext PDF. Hydrographic data, including particulate organic carbon (POC) from the Northeastern ...

  12. 75 FR 11922 - Notice of Determinations Regarding Eligibility To Apply for Worker Adjustment Assistance

    Science.gov (United States)

    2010-03-12

    .... TA-W-71,397; Teradyne, Inc., Semiconductor Test Div., CDI Talent Management, Richardson, TX. June 23..., 2008. TA-W-71,187; Cisco Systems, Inc., Network Management Technology Group, Boxborough, MA. May 18...

  13. Radiation effect on the middle ear of the guinea pig

    International Nuclear Information System (INIS)

    Harada, Hirofumi; Nishizawa, Shinji; Hiraide, Fumihisa; Inoue, Tetsuzo

    1984-01-01

    It is known that radiation therapy of the head and neck causes otitis media with effusion. Otitis media with effusion was induced in guinea pigs by cobalt-60 irradiation. Twenty guinea pigs with intact drum and normal Preyer reflex were used. We conducted, two experiments as follows: 1) The animals were irradiated with doses of 2,000 rad, 4,000 rad, and 6,000 rad. They were sacrificed seven days after the irradiation. 2) The animals were irradiated with doses of 4,000 rad and sacrificed one day, three days, seven days, and fourteen days after the irradiation. Vascular permeability of the middle ear mucosa was observed by Majno's vascular labelling technique. Pathological change of the middle ear was examined under the light microscope. Vascular permeability increased in three days after 4,000 rad irradiation and small vessels were labelled with carbon particles. Seven days after irradiation, carbon labelling of small vessels was more extensive and extravascular blackening was present in the adjacent tissues. Edematous change of the middle ear mucosa and metaplasia of the epithelial cells were also observed. New bone formation of the tympanic bulla was increased by repeated irradiations. (author)

  14. Approaches for Assessing the Presence and Impact of Thyroid Hormone Disrupting Chemicals in Delphinid Cetaceans

    Science.gov (United States)

    2006-09-01

    REFERENCES Achen MG, Harms PJ, Thomas T, Richardson SJ, Wettenhall REH, Schreiber G. 1992. Protein synthesis at the blood-brain barrier. The major...was cleaned with an antiseptic scrub and lidocaine was injected in an L-block configuration approximately 4 cm anterior to the biopsy region. For each...REFERENCES Achen MG, Harms PJ, Thomas T, Richardson SJ, Wettenhall REH, Schreiber G. 1992. Protein synthesis at the blood-brain barrier. The major

  15. Manufacturing Science of Improved Molded Optics

    Science.gov (United States)

    2013-12-05

    Evaluation of a Bench-Top Precision Glass Molding Machine, Advances in Mechanical Engineering, (04 2013): 0. doi: 10.1155/2013/178680 Erick Koontz ...reviewed journals: 3.00 (b) Papers published in non-peer-reviewed journals (N/A for none) E. Koontz , P. Wachtel, J. David Musgraves, K. Richardson...2013 Conference, Rochester, NY October 14-17 2013. E. Koontz , P. Wachtel, J. David Musgraves, K. Richardson, S. Mourad, M. Huber, A. Kunz, M

  16. College physics with an integrated approach to forces and kinematics

    CERN Document Server

    Giambattista, Alan; Richardson, Robert C

    2010-01-01

    College Physics, Third Edition is the best solution for today's college physics market. With a unique, new, approach to physics that builds a conceptual framework as motivation for the physical principles, consistent problem solving coverage strategies, stunning art, extensive end-of-chapter material, and superior media support, Giambattista, Richardson, and Richardson delivers a product that addresses today's market needs with the best tools available.

  17. Accurate Evaluation of Quantum Integrals

    Science.gov (United States)

    Galant, D. C.; Goorvitch, D.; Witteborn, Fred C. (Technical Monitor)

    1995-01-01

    Combining an appropriate finite difference method with Richardson's extrapolation results in a simple, highly accurate numerical method for solving a Schrodinger's equation. Important results are that error estimates are provided, and that one can extrapolate expectation values rather than the wavefunctions to obtain highly accurate expectation values. We discuss the eigenvalues, the error growth in repeated Richardson's extrapolation, and show that the expectation values calculated on a crude mesh can be extrapolated to obtain expectation values of high accuracy.

  18. Social Perspective Taking

    Science.gov (United States)

    2009-09-01

    groups” and engage in less stereotype-driven fear and hostility resulting in reduced impulsive and aggressive behavior (Richardson, Green , & Lago...and the physical world. London: Routledge & Kegan Paul. Batson, C. D. (1991). The altruism question: Towards a social-psychological answer...others. New York: The Guilford Press. Richardson, D. R., Green , L. R., & Lago, T. (1998). The relationship between perspective- taking and

  19. Jigsaw Semantics

    Directory of Open Access Journals (Sweden)

    Paul J. E. Dekker

    2010-12-01

    Full Text Available In the last decade the enterprise of formal semantics has been under attack from several philosophical and linguistic perspectives, and it has certainly suffered from its own scattered state, which hosts quite a variety of paradigms which may seem to be incompatible. It will not do to try and answer the arguments of the critics, because the arguments are often well-taken. The negative conclusions, however, I believe are not. The only adequate reply seems to be a constructive one, which puts several pieces of formal semantics, in particular dynamic semantics, together again. In this paper I will try and sketch an overview of tasks, techniques, and results, which serves to at least suggest that it is possible to develop a coherent overall picture of undeniably important and structural phenomena in the interpretation of natural language. The idea is that the concept of meanings as truth conditions after all provides an excellent start for an integrated study of the meaning and use of natural language, and that an extended notion of goal directed pragmatics naturally complements this picture. None of the results reported here are really new, but we think it is important to re-collect them.ReferencesAsher, Nicholas & Lascarides, Alex. 1998. ‘Questions in Dialogue’. Linguistics and Philosophy 23: 237–309.http://dx.doi.org/10.1023/A:1005364332007Borg, Emma. 2007. ‘Minimalism versus contextualism in semantics’. In Gerhard Preyer & Georg Peter (eds. ‘Context-Sensitivity and Semantic Minimalism’, pp. 339–359. Oxford: Oxford University Press.Cappelen, Herman & Lepore, Ernest. 1997. ‘On an Alleged Connection between Indirect Quotation and Semantic Theory’. Mind and Language 12: pp. 278–296.Cappelen, Herman & Lepore, Ernie. 2005. Insensitive Semantics. Oxford: Blackwell.http://dx.doi.org/10.1002/9780470755792Dekker, Paul. 2002. ‘Meaning and Use of Indefinite Expressions’. Journal of Logic, Language and Information 11: pp. 141–194

  20. Combined convective heat transfer of liquid sodium flowing across tube banks

    International Nuclear Information System (INIS)

    Ma, Ying; Sugiyama, Ken-ichiro; Ishiguro, Ryoji

    1989-01-01

    In order to clarify the heat transfer characteristics of combined convection of liquid sodium, a numerical analysis is performed for liquid sodium which flows through a single horizontal row of tubes in the direction of gravity. The correlation of heat transfer characteristics between liquid sodium and ordinary fluids is also discussed. The heat transfer characteristics at large Reynolds numbers are improved when the Richardson number is increased, and the improvement rate is enlarged with increase in p/d value, since convection effect is relatively large. However heat transfer coefficients do not differ from those of forced convection at small Reynolds numbers even when the Richardson number reaches a high value because of conduction effect. A good consistence of heat transfer characteristics of combined convection between liquid sodium and air is obtained at the same Peclet number and Richardson number. This means that the fundamental heat transfer characteristics of combined convection of liquid sodium can be investigated with ordinary fluids. (author)

  1. Fabrication and electrical characteristics for MIS diode by utilizing TiO2 ceramics

    International Nuclear Information System (INIS)

    Bae, S.H.

    1981-01-01

    Metal insulator semiconductor diodes were made by utilizing TiO 2 ceramics. Tunnel field emission is here proposed as a model for rectification in TiO 2 diode. Measurements of junction depth show very satisfactory agreement with value obtained from the Richardson plot, thus serving as additional supporting evidence of field emission in TiO 2 ceramic. The measured junction area exceeds by a factor of 10 6 the value expected by assuming field emission. The Richardson plot shows a deviation from the emission theory at low voltage, which is probably due to leakage currents which are present in MIS rutile diode. (author)

  2. Traumatic Brain Injury and PTSD Screening Efforts Evaluated Using Latent Class Analysis

    Science.gov (United States)

    2014-01-01

    Pastorek, & Thornton, 2009; Breslau, Reboussin, Anthony, & Storr, 2005; Naifeh, Richardson, Del Ben, & Elhai, 2010; Shevlin, Armour , Murphy, Houston...about a wide range of demographic characteristics, environmental exposures, and com- bat experiences. The Post-Deployment Health Reassessment (PDHRA...treatment, responses from the PDHRA were used. Demographic variables. Demographic variables included age, military pay grade, and branch of service. All

  3. Denver Public Library Western History/Genealogy Digital Collections

    Science.gov (United States)

    box. Results will be a list of records that contain those words anywhere in the record. Refine your Henry Jackson Photos William Henry Jackson: American West Mining Photos Mining Louis Charles McClure Photos Louis Charles McClure: Colorado Otto Perry Photos Otto Perry: Railroads Robert W. Richardson

  4. High Performance Work Systems

    NARCIS (Netherlands)

    J.P.P.E.F. Boselie (Paul); A. van der Wiele (Ton)

    2002-01-01

    textabstractResearch, summarized and classified in the work of Delery and Doty (1996), Guest (1997), Paauwe and Richardson (1997) and Boselie et al. (2001), suggests significant impact of Human Resources Management (HRM) on the competitive advantage of organizations. The mainstream research on this

  5. Genetic structure of Pseudococcus microcirculus (Hemiptera ...

    Indian Academy of Sciences (India)

    Department of Biology, Armstrong State University, Savannah, GA 31419, USA. Abstract ... [Zettler J. A., Adams K., Frederick B., Gutting A., Ingebretsen N., Ragsdale A. and Schrey A. 2017 Genetic structure of Pseudococcus ..... Park) and Larry Richardson (Florida Panther Wildlife Refuge) for ... University Press of Florida,.

  6. maximum conversion efficiency of thermionic heat to electricity

    African Journals Online (AJOL)

    DJFLEX

    Dushman constant ... Several attempts on the direct conversion of heat to electricity ... The net current density in the system is equal to jE – jC , which gets over the potential barrier. jE and jC are given by the Richardson-. Dushman equation as. │. ⌋.

  7. Speaking to the Ghost: An Autoethnographic Journey with Elwyn

    Science.gov (United States)

    Heyward, Paul; Fitzpatrick, Esther

    2016-01-01

    As educators we are haunted. This haunting takes place on several levels, through our personal histories, through key theoretical ideas we have encountered on our journeys, and by those significant educators who have gone before. This paper highlights how Elwyn S. Richardson continues to haunt education in New Zealand. Also how Elwyn, in turn, was…

  8. When a Student Does Not Want to Be in School: A Reading of Paulo Freire through Family Alcoholism Discourse

    Science.gov (United States)

    Johnson, Edric C.

    2009-01-01

    As Richardson reminds us, "People make sense of their lives, for the most part, in terms of specific events." The author develops a set of poems based on his autoethnography study on Children of Alcoholics (COA). As the author reads Paulo Freire through alcoholism discourse, he creates a link between COA and his own school experiences.…

  9. 76 FR 18167 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Science.gov (United States)

    2011-04-01

    ..., many marine animals may need to remain in areas where they are exposed to chronic stimuli (Richardson... Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the Central Gulf of Alaska, June, 2011 AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric...

  10. 76 FR 6430 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Science.gov (United States)

    2011-02-04

    ..., many marine animals may need to remain in areas where they are exposed to chronic stimuli (Richardson... Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the Pacific Ocean off Costa Rica, April Through May, 2011 AGENCY: National Marine Fisheries Service (NMFS), National Oceanic...

  11. 76 FR 57959 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Science.gov (United States)

    2011-09-19

    ..., many marine animals may need to remain in areas where they are exposed to chronic stimuli (Richardson... Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the Central Pacific Ocean, November, 2011 Through January, 2012 AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and...

  12. 76 FR 76759 - Certain Portable Communication Devices, Receipt of Complaint; Solicitation of Comments Relating...

    Science.gov (United States)

    2011-12-08

    ... Park, New Jersey; Samsung Telecommunications America, LLC of Richardson, TX; Sony Corporation of Japan; Sony Corporation of America of New York, NY; Sony Electronics, Inc. of San Diego, CA; Sony Ericsson...; Research In Motion Corp. of Irving, TX; HTC Corporation of Taiwan; HTC America, Inc. of Bellevue, WA; LG...

  13. 77 FR 515 - Certain Portable Communication Devices; Receipt of Amended Complaint; Solicitation of Comments...

    Science.gov (United States)

    2012-01-05

    ... Telecommunications America, LLC of Richardson, TX; Sony Corporation of Japan; Sony Corporation of America of New York, NY; Sony Electronics, Inc. of San Diego, CA; Sony Ericsson Mobile Communication AB of Sweden; Sony... Corp. of Irving, TX; HTC Corporation of Taiwan; HTC America, Inc. of Bellevue, WA; LG Electronics, Inc...

  14. 78 FR 77713 - Notice of Receipt of Complaint; Solicitation of Comments Relating to the Public Interest

    Science.gov (United States)

    2013-12-24

    ... Telecommunications America, L.L.C. of Richardson, TX; Sony Corporation of Japan; Sony Mobile Communications AB of Sweden; Sony Mobile Communications (USA), Inc. of Atlanta, GA; ZTE Corporation of China and ZTE (USA) Inc... respondents Nokia Corporation (Nokia Oyj) of Finland; Nokia, Inc. of Sunnyvale, CA; Samsung Electronics Co...

  15. 77 FR 17094 - In the Matter of Certain Portable Communication Devices Commission Determination Not To Review an...

    Science.gov (United States)

    2012-03-23

    ... Richardson, Texas; Sony Corporation of Tokyo, Japan; Sony Corporation of America of New York, New York; Sony Electronics, Inc. of San Diego, California; Sony Ericsson Mobile Communications AB of Lund, Sweden; Sony...; Research In Motion Corp. of Irving, Texas; HTC Corporation of Taoyuan, Taiwan; HTC America, Inc. of...

  16. 78 FR 66361 - Proposed Data Collections Submitted for Public Comment and Recommendations

    Science.gov (United States)

    2013-11-05

    ... CDC/ATSDR LeRoy Richardson, 1600 Clifton Road, MS D- 74, Atlanta, GA 30333 or send an email to [email protected] Heart Attack and Stroke; Lactation Support; Community Resources; Occupational Health and Safety; and... education staff, occupational nurses, medical directors, wellness directors, or others responsible for...

  17. Invertebrates of Meadow Creek, Union County, Oregon, and their use as food by trout.

    Science.gov (United States)

    Carl E. McLemore; William R. Meehan

    1988-01-01

    From 1976 to 1980, invertebrates were collected three times each year from several reaches of Meadow Creek in eastern Oregon. Five sampling methods were used: benthos, drift, sticky traps, water traps, and fish stomachs. A total of 372 taxa were identified, of which 239 were used as food by rainbow trout (steelhead; Salmo gairdneri Richardson). Of...

  18. Cape anchovy Engraulis capensis spawn mainly east of Cape Point ...

    African Journals Online (AJOL)

    spamer

    In the southern Benguela, successful recruitment of Cape anchovy Engraulis capensis is ... Based on the total area of 16–19°C water on the western Agulhas. Bank, Richardson et al. .... in the zone, φ the new value, and β is a relaxation pa-.

  19. Large-Scale Operations Management Test of Use of the White Amur for Control of Problem Aquatic Plants. Report 2. First Year Poststocking Results. Volume VII. A Model for Evaluation of the Response of the Lake Conway, Florida, Ecosystem to Introduction of the White Amur.

    Science.gov (United States)

    1981-11-01

    Ecol. 6:311-338. 175. Widmer, C., T. Kittel, and P. J. Richardson. 1975. A survey of the biological limnology of Lake Titicaca . Verh. Internat. Verein...170 Lake Titicaca 175 0.293 Lake Tahoe 170 0.035 Submersed Plants Hydrila verticillata 1290 Ceratophyllum demersum 4831 Myriophylure spicatum 2097

  20. Publications - Geospatial Data | Alaska Division of Geological &

    Science.gov (United States)

    from rocks collected in the Richardson mining district, Big Delta Quadrangle, Alaska: Alaska Division Island 2009 topography: Alaska Division of Geological & Geophysical Surveys Miscellaneous Publication , Geologic map of portions of the Livengood B-3, B-4, C-3, and C-4 quadrangles, Tolovana mining district

  1. Sex-Specific Response Strategies in Mental Rotation

    Science.gov (United States)

    Hirnstein, Marco; Bayer, Ulrike; Hausmann, Markus

    2009-01-01

    The present study investigated whether the marked sex difference in the original mental rotation test (MRT) is simply a result of sex differences in response strategies. Thirty-four participants (17 males, 17 females) completed the revised Vandenberg and Kuse MRT [Peters, M., Laeng, B., Latham, K., Jackson, M., Zaiyouna, R., & Richardson, C.…

  2. Tensor product varieties and crystals. GL case

    OpenAIRE

    Malkin, Anton

    2001-01-01

    The role of Spaltenstein varieties in the tensor product for GL is explained. In particular a direct (non-combinatorial) proof of the fact that the number of irreducible components of a Spaltenstein variety is equal to a Littlewood-Richardson coefficient (i.e. certain tensor product multiplicity) is obtained.

  3. Interpreting IDR(s) as a deflation method

    NARCIS (Netherlands)

    Collignon, T.P.; Sleijpen, G.L.G.; Van Gijzen, M.B.

    2010-01-01

    In this paper the IDR(s) method is interpreted in the context of deflation methods. It is shown that IDR(s) can be seen as a Richardson iteration preconditioned by a variable deflation–type preconditioner. The main result of this paper is the IDR projection theorem, which relates the spectrum of the

  4. Data Drive These Coaches: Literacy Project Merges School Goals with Teachers' Learning Needs

    Science.gov (United States)

    Ittner, Anne; Helman, Lori; Burns, Matthew; McComas, Jennifer

    2015-01-01

    Research highlights the importance of individualized approaches and coaching to ongoing professional learning (Darling-Hammond, Wei, Andree, Richardson, & Orphanos, 2009). The purpose of this article is to describe an initiative that set out to help all students become proficient readers by 3rd grade. It demonstrates how coaching can support…

  5. Art-at-Work: Moving Beyond, with the Histories of Education and Art in Aotearoa New Zealand

    Science.gov (United States)

    Craw, Janita; O'Sullivan, Victoria

    2016-01-01

    This article reports on "Art-at-Work," a twenty-four-hour exhibition that took place on Auckland University of Technology's (AUT) North Shore campus on 17 July 2013. The passing away of progressive educator Elwyn S. Richardson (1925-2012) was the catalyst for this project that emerged simultaneously alongside the Elwyn S. Richardson…

  6. Why I Got Tested for Colorectal Cancer

    Centers for Disease Control (CDC) Podcasts

    2016-02-29

    CDC’s Dr. Lisa Richardson explains why she got tested for colorectal cancer when she turned 50 years old. .  Created: 2/29/2016 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 2/29/2016.

  7. INFLUENCE OF TYPE II DIABETES AND OBESITY ON THE DISPOSITION AND ELIMINATION OF TCDD IN MICE

    Science.gov (United States)

    INFLUENCE OF TYPE II DIABETES AND OBESITY ON THE DISPOSTION AND ELIMINATION OF TCDD IN MICE. MJ DeVito', JJ Diliberto', DG Ross', C Emond2, VM Richardson', and LS Birnbaum', 'ETD, NHEERL, ORD, US EPA, RTP, NC, 27711, USA, 2National Research Council.One possible explanation fo...

  8. CONCLUSION It is obvious that a diagnosis of breast cancer causes ...

    African Journals Online (AJOL)

    Sitwala

    Psychology.1989; 56 (2) 267-183. 5. Kearney, N. and Richardson, A. (2006). Nursing. Patients with Cancer: Principles and Practice. Elsevier, London. 6. .... These patients may have normal vision, a normal neurological examination and normal plain radiographs, despite trauma that may. 2 lead to significant Complications.

  9. Is Bureaucracy Compatible with Democracy? | Koll | South African ...

    African Journals Online (AJOL)

    If such inequality in decision making power is indeed a real threat, it will turn out that bureaucratic organisations, while being largely motivated by considerations of procedural fairness, may in fact constitute quite unfair procedures. Richardson proposes some institutional reforms that he thinks will enable us to avoid being ...

  10. Symmetric group representations and Z

    OpenAIRE

    Adve, Anshul; Yong, Alexander

    2017-01-01

    We discuss implications of the following statement about the representation theory of symmetric groups: every integer appears infinitely often as an irreducible character evaluation, and every nonnegative integer appears infinitely often as a Littlewood-Richardson coefficient and as a Kronecker coefficient.

  11. A Case Study Exploring the Utilization of Fantasy Football and Its Effect on Teacher Morale

    Science.gov (United States)

    Ryan, Scott

    2014-01-01

    The purpose of this case study was to investigate if teacher morale increased, as measured on the Staff Morale Questionnaire (Smith, 1976), after the implementation of a fantasy football league on a secondary campus in southeast Texas. Teaching is an occupation with a high turnover rate (Briggs & Richardson, 1992; Ingersol, 2003; Rafferty,…

  12. 78 FR 6130 - Certain Electronic Digital Media Devices and Components Thereof: Commission Determination To...

    Science.gov (United States)

    2013-01-29

    ... a domestic industry. The respondents named in the Commission's notice of investigation are Samsung Electronics Co, Ltd. of Korea; Samsung Electronics America, Inc. of Ridgefield Park, New Jersey; and Samsung Telecommunications America, LLC of Richardson, Texas (collectively, ``Samsung''). A Commission investigative attorney...

  13. 77 FR 68829 - Certain Electronic Digital Media Devices and Components Thereof; Notice of Request for Statements...

    Science.gov (United States)

    2012-11-16

    ... electronic digital media devices and components thereof imported by respondents Samsung Electronics Co, Ltd. of Korea; Samsung Electronics America, Inc. of Ridgefield Park, New Jersey; and Samsung Telecommunications America, LLC of Richardson, Texas (collectively ``Samsung''), and cease and desist orders against...

  14. Studies in the History of Business Writing.

    Science.gov (United States)

    Douglas, George H., Ed.; Hildebrandt, Herbert W., Ed.

    Because written communication has nearly always been the medium for transmitting information in the business world, these essays are a step toward providing a seminal statement on the history and practice of business writing. The essays in this volume are: "Business Writing and the Spread of Literacy in Late Medieval England" (Malcolm Richardson);…

  15. Selecting, Evaluating and Creating Policies for Computer-Based Resources in the Behavioral Sciences and Education.

    Science.gov (United States)

    Richardson, Linda B., Comp.; And Others

    This collection includes four handouts: (1) "Selection Critria Considerations for Computer-Based Resources" (Linda B. Richardson); (2) "Software Collection Policies in Academic Libraries" (a 24-item bibliography, Jane W. Johnson); (3) "Circulation and Security of Software" (a 19-item bibliography, Sara Elizabeth Williams); and (4) "Bibliography of…

  16. Sync or separate? No compelling evidence for unintentional interpersonal coordination between Usain Bolt and Tyson Gay on the 100-meter world record race

    NARCIS (Netherlands)

    Blikslager, Frank; de Poel, Harjo

    2017-01-01

    In a recent observation article in Journal of Experimental Psychology: Human Perception and Performance (JEP:HPP; Varlet & Richardson, 2015) the 100-m sprint final of the World Championship in Athletics in Berlin of 2009 (i.e., the current world record race) was analyzed. That study reported

  17. 75 FR 18164 - Procurement List: Proposed Additions and Deletions

    Science.gov (United States)

    2010-04-09

    ... . SUPPLEMENTARY INFORMATION: This notice is published pursuant to 41 U.S.C. 47(a)(2) and 41 CFR 51-2.3. Its.../Location: Janitorial Services, Corp of Engineers Buildings, Elmendorf AFB, AK, Corp of Engineers Buildings, Fort Richardson, AK. NPA: MQC Enterprises, Inc., Anchorage, AK. Contracting Activity: XR W2SN ENDIST...

  18. Troubling the Proletarianization of Mexican Immigrant Students in an Era of Neoliberal Immigration

    Science.gov (United States)

    Choudry, Aziz

    2010-01-01

    In response to Richardson Bruna's "Mexican immigrant transnational social capital and class transformation: examining the role of peer mediation in insurgent science", this paper draws on the author's research on organizing, mobilization and knowledge production among adult im/migrant workers in Canada. While appreciative of the content…

  19. New York Bight Study: Report 5, NY Bight Biological Review Program

    Science.gov (United States)

    1994-05-01

    final cap has been recolonized due to changes in granulome - tVy and stress from chronic burial. The procedure and information available for examining this...34 Linear oceanographic features: A focus for research on recruitment processes," Australian Journal of Ecology 15, 391-401. Kiorboe, T., Munk, P., Richardson

  20. Building a Unit-Level Mentored Program to Sustain a Culture of Inquiry for Evidence-Based Practice

    Science.gov (United States)

    2015-03-24

    Melnyk and Eileen Fineout-Overholt, who graciously and consistently support military nursing science. Building a Unit-Level Mentored Program...Rosenberg W, Gray JA, Haynes RB, Richardson WS. Evidence based medicine: What it is and what it isn’t. BMJ. 1996;312(7023):71-72.doi: http

  1. 78 FR 11821 - Takes of Marine Mammals Incidental to Specified Activities; Low-Energy Marine Geophysical Survey...

    Science.gov (United States)

    2013-02-20

    ... engines and an 80 horsepower (hp) Schottel bowthruster. Electrical power is provided by two Caterpillar... (ms). The sub-bottom profiler is operated continuously during survey operations. Power levels of the... receiving animals (hearing, motivation, experience, demography) and is also difficult to predict (Richardson...

  2. Effect of Captioned Film Instructional Package (CFIP) on Academic ...

    African Journals Online (AJOL)

    Researcher-made English language Performance Test (RELPT) was used for the data collection of the study. Kuder Richardson formula (K-R 20) was used to obtain the reliability coefficient of 0.88. Research question and hypothesis were tested using mean, standard deviation and Analysis of Covariance. The study ...

  3. Temperature dependent current-voltage characteristics of Au/n-Si Schottky barrier diodes and the effect of transition metal oxides as an interface layer

    Science.gov (United States)

    Mahato, Somnath; Puigdollers, Joaquim

    2018-02-01

    Temperature dependent current-voltage (I‒V) characteristics of Au/n-type silicon (n-Si) Schottky barrier diodes have been investigated. Three transition metal oxides (TMO) are used as an interface layer between gold and silicon. The basic Schottky diode parameters such as ideality factor (n), barrier height (ϕb 0) and series resistance (Rs) are calculated and successfully explained by the thermionic emission (TE) theory. It has been found that ideality factor decreased and barrier height increased with increased of temperature. The conventional Richardson plot of ln(I0/T2) vs. 1000/T is determined the activation energy (Ea) and Richardson constant (A*). Whereas value of 'A*' is much smaller than the known theoretical value of n-type Si. The temperature dependent I-V characteristics obtained the mean value of barrier height (ϕb 0 bar) and standard deviation (σs) from the linear plot of ϕap vs. 1000/T. From the modified Richardson plot of ln(I0/T2) ˗ (qσ)2/2(kT)2 vs. 1000/T gives Richardson constant and homogeneous barrier height of Schottky diodes. Main observation in this present work is the barrier height and ideality factor shows a considerable change but the series resistance value exhibits negligible change due to TMO as an interface layer.

  4. Comparison of image deconvolution algorithms on simulated and laboratory infrared images

    Energy Technology Data Exchange (ETDEWEB)

    Proctor, D. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    We compare Maximum Likelihood, Maximum Entropy, Accelerated Lucy-Richardson, Weighted Goodness of Fit, and Pixon reconstructions of simple scenes as a function of signal-to-noise ratio for simulated images with randomly generated noise. Reconstruction results of infrared images taken with the TAISIR (Temperature and Imaging System InfraRed) are also discussed.

  5. Tools to Compare Diving-Animal Kinematics with Acoustic Behavior and Exposure

    Science.gov (United States)

    2011-09-30

    to humpback whales; under Dr. Stephen Insley, then at the University of California at Santa Cruz , to northern fur seals (Figure 3; Insley et al...Richardson (Anchorage, Alaska) and Dr. Manuel Castellote of the National Marine Mammal Laboratory to assess applicability of the Acousonde 3B to

  6. metateoretiese perspektiewe op liggaamlike probleme as moontlike ...

    African Journals Online (AJOL)

    Liezel

    E-pos: wentzelcoetzer@telkomsa.net. Ds. H.P. Kotzé ..... vanuit 'n pastorale hoek was die Franse medikus en teoloog, Paul Tournier ... (1996); Arterburn (2005); Richardson (2005); Seamands (2003); John & Paula ... Collins (1988); Anderson et al. ... The healing power of the Christian mind: How Biblical truth can keep you.

  7. American Indian/Alaska Native Voices in the Model of Institutional Adaptation to Student Diversity

    Science.gov (United States)

    Guillory, Raphael; Wolverton, Mimi; Appleton, Valerie

    2008-01-01

    Richardson and Skinner (1991) in their Model of Institutional Adaptation to Student Diversity (MIASD) assert that state higher education boards have significant influence on the degree to which institutions respond to student diversity. The purpose of the study (conducted in the 2001-2002 school year) reported in this article was to determine…

  8. Accuracy of MR markers for differentiating Progressive Supranuclear Palsy from Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Stefano Zanigni

    2016-01-01

    Conclusion: Although several quantitative brain MR markers provided high diagnostic accuracy in differentiating Progressive Supranuclear Palsy-Richardson's Syndrome from Parkinson's disease, the morphometric assessment of midbrain area is the best single diagnostic marker and should be routinely included in the neuroradiological work-up of parkinsonian patients.

  9. Disruptive Technology for Vector Control: the Innovative Vector Control Consortium and the US Military Join Forces to Explore Transformative Insecticide Application Technology for Mosquito Control Programmes

    Science.gov (United States)

    2015-09-26

    Jennifer Knapp1, Michael Macdonald2, David Malone3, Nicholas Hamon3 and Jason H. Richardson4* Abstract Malaria vector control technology has remained...control of Aedes albopictus in residential neighborhoods: from optimiza- tion to operation. PLoS One. 2014;9:e110035. 22. Lee VJ, Ow S, Heah H, Tan MY

  10. Ground-level air pollution changes during a boreal wildland mega-fire

    Science.gov (United States)

    Andrzej Bytnerowicz; Yu-Mei Hsu; Kevin Percy; Allan Legge; Mark E. Fenn; Susan Schilling; Witold Frączek; Diane Alexander

    2016-01-01

    The 2011 Richardson wildland mega-fire in the Athabasca Oil Sands Region (AOSR) in northern Alberta, Canada had large effects on air quality. At a receptor site in the center of the AOSR ambient PM2.5, O3, NO, NO2, SO2, NH3, HONO, HNO3...

  11. 75 FR 30387 - Improving Market and Planning Efficiency Through Improved Software; Notice of Agenda and...

    Science.gov (United States)

    2010-06-01

    ... on the Commission's Web site at http://www.ferc.gov . A free Webcast of this event is available... navigating to http://www.ferc.gov 's Calendar of Events and locating this event in the calendar. The event.... Jinxiang Zhu, ABB. Devin Van Zandt, GE. 12:30 p.m Lunch. 1:30 p.m Norm Richardson, Ventyx. John Condren...

  12. 75 FR 24906 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Science.gov (United States)

    2010-05-06

    ... physical effects; and, at least in theory, temporary or permanent hearing impairment (Richardson et al... based on measured received levels and the hearing sensitivity of that mammal group. Although various... must adapt, the introduction of strong sounds into the sea at frequencies important to marine mammals...

  13. 75 FR 53266 - United States Army Restricted Area, Designated Portions of Eagle Bay and Eagle River, Fort...

    Science.gov (United States)

    2010-08-31

    ... Richardson, Alaska as well as an adjacent portion of Eagle Bay in the Knik Arm. More specifically, the... affected waters of Eagle Bay and Eagle River in order to enhance safety and security. This portion of Eagle... B. Olson), 441 G Street, NW., Washington, DC 20314-1000. Hand Delivery/Courier: Due to security...

  14. 76 FR 69957 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Science.gov (United States)

    2011-11-09

    .... Department of the Interior, Bureau of Ocean Energy Management (BOEM, formerly the Minerals Management [[Page... likely to mask short-distance acoustic communication (Richardson et al., 1995a). Although some masking by... can influence an animal's perception of and response to (in both nature and magnitude) an acoustic...

  15. MicroRNA Gene Regulatory Networks in Peripheral Nerve Sheath Tumors

    Science.gov (United States)

    2012-09-01

    1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202- 4302. Respondents should be aware that notwithstanding any other provision of law , no...Reinhardt F, Benaich N, Calogrias D, Szasz AM, Wang ZC, Brock JE, Richardson AL, Weinberg RA (2009) A pleiotropically acting microRNA, miR-31, inhibits breast

  16. Ecological Metissage: Exploring the Third Space in Outdoor and Environmental Education

    Science.gov (United States)

    Lowan, Greg

    2011-01-01

    Metis scholar Catherine Richardson introduced the concept of the "Third Space" as the existentially blended territory of a Metis mentality. She compared this to the "First Space" of the dominant Euro-Canadian society and the "Second Space" of colonially subjugated Aboriginal peoples. However, during a recent…

  17. "No Rugby--No Fear": Collective Stories, Masculinities and Transformative Possibilities in Schools

    Science.gov (United States)

    Pringle, Richard

    2008-01-01

    This paper contributes to the development of a critical pedagogy in physical education (PE) by illustrating how "collective stories" can be used within schools to help raise awareness of the relationships between sport, PE and gendered identities. A collective story, a concept developed by Laurel Richardson, aims to give voice to those…

  18. 78 FR 32474 - Request for Comments: LSC Appropriations Request for FY 2015

    Science.gov (United States)

    2013-05-30

    ... testify at the Finance Committee meeting on June 11, 2013 should be sent to David Richardson, by email at... sequestration and two rescissions) of $339,926,165, of which $316,144,749 is for basic field programs and... following calendar year. The Finance Committee of the LSC Board of Directors will meet at 12 p.m., EDT, on...

  19. Proceedings of the Workshop on Gulf Stream Structure and Variability Held at Research Triangle Park, North Carolina on 1-2 April 1982.

    Science.gov (United States)

    1982-04-01

    recently been re-discovered (Richardson, 1980). Franklin’s grand-nephew, Jonathan Williams (1793), applied his uncle’s ideas about thermometric naviga...spheres instead of aluminum tubes. This makes them lighter and easier to handle and permits us to profile to greater depths than before. The data are

  20. South African Journal of Sports Medicine - Vol 26, No 2 (2014)

    African Journals Online (AJOL)

    Effect of caffeine ingestion on fluid balance during exercise in the heat and during recovery · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Y Zhang, SJ Carter, RE Schumacker, YH Neggers, MD Curtner-Smith, MT Richardson, JM Green, PA Bishop, 43-47.

  1. 2208-IJBCS-Article-Folunsho Abayomi

    African Journals Online (AJOL)

    hp

    produces serious ecological and economic problems (Richardson et al., 2000). The main consequence on .... circular to angular in cross section and the mean vessel diameter is 67.5 μm. Starch grains are present within the ... Vessel shape varies from elliptic to circular in cross section; the mean vessel diameter is 58.0 μm.

  2. ProRegIn: A regularity index for the selection of native-like tertiary ...

    Indian Academy of Sciences (India)

    Prakash

    2006-12-18

    Dec 18, 2006 ... for improvement as they often limit the prediction quality. (Jacobson et al ... Supplementary Data pertaining to this article is available on the Journal of Biosciences Website at ..... Richardson J S 1981 The anatomy and taxonomy of protein ... of homologous proteins, Part I: three dimensional frameworks.

  3. Solutions of nuclear pairing

    International Nuclear Information System (INIS)

    Balantekin, A. B.; Pehlivan, Y.

    2007-01-01

    We give the exact solution of orbit dependent nuclear pairing problem between two nondegenerate energy levels using the Bethe ansatz technique. Our solution reduces to previously solved cases in the appropriate limits including Richardson's treatment of reduced pairing in terms of rational Gaudin algebra operators

  4. Marketing the Program. New Directions for Community Colleges, Number 36.

    Science.gov (United States)

    Keim, William A., Ed.; Keim, Marybelle C., Ed.

    1981-01-01

    This collection of essays examines the role of marketing in the recruitment and retention of community college students. First, Philip Kotler and Leslie A. Goldgehn define the marketing process and assess its potential benefits. Richard C. Richardson, Jr., and Donald S. Doucette question the effectiveness of marketing in the community college.…

  5. Fulltext PDF

    Indian Academy of Sciences (India)

    Construction of the ribbon model of proteins (1981) ... Protein design; protein folding; representation; ribbon model; super-secondary structure; synthetic biology ... still expressed amazement that 'a whole generation of scientists see protein structures through my eyes' (Bahar 2004). 3. The contribution of Jane Richardson.

  6. ONRASIA Scientific Information Bulletin

    Science.gov (United States)

    1993-12-01

    with volcanic eruptions. backbone hierarchical KREONET, that currently "* Extracorporeal shock wave lithotripsy independent research and educational...Zone, East Indonesia: Dpt., Southampton University, Southampton Adrian Richardson, Dpt. of Geology, Royal S09 5NH, U.K. ***Dpt. of Geological Sciences

  7. Sleep, Wakefulness and Circadian Rhythm

    Science.gov (United States)

    1979-09-01

    Prevalence of cardiac arrhythmias and their reversal after trach- ostomy . An. J. Ned., 63, 1977, 348-358. 69. Richardson, G. S., Carsk..on, M. A., Flagg, W...balanced distribution of sleep stages Avid the hoped for effect of refreshing sleep is disappointed. But snort periods Of 3leep Of about C haours can lead

  8. An evaluation of the use of blood metabolite concentrations as ...

    African Journals Online (AJOL)

    Unknown

    Data was analyzed statistically for differences between months using the Friedman test, and for differences between localities and between physiological states using the T-test ..... D., Occasional Publication No 1, British Society of Animal Production, Milton Keynes, pp. 3-12. Richardson, F. D. and Kegel, L., 1980. The use of ...

  9. 78 FR 13379 - Wrangell-St. Elias National Park and Preserve, Alaska; Proposed Mining Plan of Operations

    Science.gov (United States)

    2013-02-27

    ...] Wrangell-St. Elias National Park and Preserve, Alaska; Proposed Mining Plan of Operations AGENCY: National...) unpatented placer claims within Wrangell-St. Elias National Park and Preserve. Public Availability: This plan...: Wrangell-St. Elias National Park and Preserve Headquarters, Mile 106.8 Richardson Highway, Post Office Box...

  10. Fulltext PDF

    Indian Academy of Sciences (India)

    Richardson was studying the border between Spain and. Portugal, which had been the source of dispute between the two nations. He found that in Spanish encyclopaedias the border was 987 km long whereas the Portuguese encyclo- paedia put ... decreasing the length of the scale has no effect on the length of a straight ...

  11. Particle image velocimetry measurements and numerical modeling of a saline density current

    CSIR Research Space (South Africa)

    Gerber, G

    2011-03-01

    Full Text Available Particle image velocimetry scalar measurements were carried out on the body of a stably stratified density current with an inlet Reynolds number of 2,300 and bulk Richardson number of 0.1. These measurements allowed the mass and momentum transport...

  12. 78 FR 77490 - Certain Electronic Imaging Devices; Notice of Commission Determination To Review-in-Part a Final...

    Science.gov (United States)

    2013-12-23

    ... and Pantech Wireless, Inc. of Atlanta, Georgia (collectively, ``Pantech''); Huawei Technologies Co., Ltd. of Shenzhen, China; FutureWei Technologies, Inc. d/b/a Huawei Technologies (USA) of Plano, Texas (collectively ``Huawei''); ZTE Corporation of Shenzhen, China; and ZTE (USA) Inc. of Richardson, Texas...

  13. Staff Views of the Importance of Relationships for Knowledge Development: Is Training by Specialists a Waste of Money?

    Science.gov (United States)

    Bradshaw, Jill; Goldbart, Juliet

    2013-01-01

    Background: The provision of skilled support is dependent on staff knowledge and understanding (Beadle-Brown J., Beecham J., Mansell J., Baumker T., Leigh J., Whelton R. & Richardson L, unpublished data). Influencing staff knowledge and understanding is an important component of interventions. Materials and Methods: Fourteen individual…

  14. Class-first analysis in a continuum: an approach to the complexities of schools, society, and insurgent science

    Science.gov (United States)

    Valdiviezo, Laura Alicia

    2010-06-01

    This essay addresses Katherine Richardson Bruna's paper: Mexican Immigrant Transnational Social Capital and Class Transformation: Examining the Role of Peer Mediation in Insurgent Science, through five main points . First, I offer a comparison between the traditional analysis of classism in Latin America and Richardson Bruna's call for a class-first analysis in the North American social sciences where there has been a tendency to obviate the specific examination of class relations and class issues. Secondly, I discuss that a class-first analysis solely cannot suffice to depict the complex dimensions in the relations of schools and society. Thus, I suggest a continuum in the class-first analysis. Third, I argue that social constructions surrounding issues of language, ethnicity, and gender necessarily intersect with issues of class and that, in fact, those other constructions offer compatible epistemologies that aid in representing the complexity of social and institutional practices in the capitalist society. Richardson Bruna's analysis of Augusto's interactions with his teacher and peers in the science class provides a fourth point of discussion in this essay. As a final point in my response I discuss Richardson Bruna's idea of making accessible class-first analysis knowledge to educators and especially to science teachers.

  15. Interrelationship between cloud cover and sensible heat flux over ...

    Indian Academy of Sciences (India)

    Formation of deep depression in the north Bay of Bengal where u∗ is friction velocity and θ∗ is character- istic temperature. As temperature and wind were measured at the same levels during MONTBLEX, in Businger–Dyer forms of the universal functions, the stability parameter (Z/L) is replaced in terms of the Richardson ...

  16. Partisan Differences on Higher Education Accountability Policy: A Multi-State Study of Elected State Legislators

    Science.gov (United States)

    Morse, Andrew Q.

    2014-01-01

    Public institutions in the United States face a policy challenge to adapt to accountability expectations among a variety of stakeholders (Bogue & Hall, 2012; Thelin, 2004; Richardson & Martinez, 2009). Among the major stakeholders are state legislators who hold fiscal and policy influence over public institutions, but these leaders have…

  17. Auditory Memory Distortion for Spoken Prose

    Science.gov (United States)

    Hutchison, Joanna L.; Hubbard, Timothy L.; Ferrandino, Blaise; Brigante, Ryan; Wright, Jamie M.; Rypma, Bart

    2012-01-01

    Observers often remember a scene as containing information that was not presented but that would have likely been located just beyond the observed boundaries of the scene. This effect is called "boundary extension" (BE; e.g., Intraub & Richardson, 1989). Previous studies have observed BE in memory for visual and haptic stimuli, and…

  18. Secrets of the Presidential Turn-Around Artist.

    Science.gov (United States)

    Fields, Cheryl D.

    2002-01-01

    Profiles five college presidents (Henry Tisdale of Claflin University, David Carter of Eastern Connecticut State University, Jimmy Jenkins of Edward Waters College, Dorothy Yancy of Johnson C. Smith University, and Luns Richardson of Morris College) who have brought success to their once-languishing institutions. (EV)

  19. 78 FR 30964 - Pipeline Safety: Workshop on Public Awareness Programs

    Science.gov (United States)

    2013-05-23

    ... Richardson, Texas. The workshop serves as an opportunity to bring pipeline safety stakeholders together to..., and excavators) will share their perspectives on what is working and what is not working with existing... discuss recent inspection findings; (2) Understand what's working and not working with public awareness...

  20. Strategic Performance Options in Professional Service Organizations

    NARCIS (Netherlands)

    Doorewaard, J.A.C.M.; Meihuizen, H.E.

    2000-01-01

    In the current debate on HRM and organisational performance (Mahoney and Pandian, 1992; Storey, 1992; Paauwe, 1994; Wright et al, 1994; Flood et al, 1995; Becker and Gerhardt, 1996; Boxall, 1996; Mueller, 1996; Beatty and Schneider, 1997; Coff, 1997; Guest, 1997; Paauwe and Richardson, 1997; Boxall

  1. Browse Title Index

    African Journals Online (AJOL)

    Items 101 - 150 of 255 ... Vol 2, No 2 (2002), Heal My Heart: Stories of Hurt and Healing from Group Therapy, Abstract PDF. Zelda Knight. Vol 10, No 1 (2010), Health and ... Maurice Apprey. Vol 6, No 1 (2006), Imaging the Visceral Soma: A Corporeal Feminist Interpretation, Abstract PDF. Ingrid Richardson, Carly Harper.

  2. Environmental Assessment for the Expansion of the Elmendorf AFB Gravel Pit

    Science.gov (United States)

    2008-04-01

    portions of the herd migrate off base in fall and winter. To help reduce moose numbers on military lands, Fort Richardson held annual hunts. The...muskrat (Ondatra zibethicus), porcupine (Erethizon dorsatum), red squirrel (Tamiasciurus hudsonicus), snowshoe hare, river otter (Lutra canadensis

  3. Book Reviews

    Directory of Open Access Journals (Sweden)

    Redactie KITLV

    2008-12-01

    Full Text Available Ileana Rodríguez; Transatlantic Topographies: Islands, Highlands, Jungles (Stuart McLean Eliga H. Gould, Peter S. Onuf (eds.; Empire and Nation: The American Revolution in the Atlantic World (Peter A. Coclanis Michael A. Gomez; Reversing Sail: A History of the African Diaspora (James H. Sweet Brian L. Moore, Michele A. Johnson; Neither Led Nor Driven: Contesting British Cultural Imperialism in Jamaica, 1865-1920 (Gad Heuman Erna Brodber; The Second Generation of Freemen in Jamaica, 1907-1944 (Michaeline A. Crichlow Steeve O. Buckridge; The Language of Dress: Resistance and Accommodation in Jamaica, 1760- 1890 (Jean Besson Deborah A. Thomas; Modern Blackness: Nationalism, Globalization, and the Politics of Culture in Jamaica (Charles V. Carnegie Carolyn Cooper; Sound Clash: Jamaican Dancehall Culture at Large (John D. Galuska Noel Leo Erskine; From Garvey to Marley: Rastafari Theology (Richard Salter Hilary McD Beckles; Great House Rules: Landless Emancipation and Workers’ Protest in Barbados, 1838?1938 (O. Nigel Bolland Woodville K. Marshall (ed.; I Speak for the People: The Memoirs of Wynter Crawford (Douglas Midgett Nathalie Dessens; Myths of the Plantation Society: Slavery in the American South and the West Indies (Lomarsh Roopnarine Michelle M. Terrell; The Jewish Community of Early Colonial Nevis: A Historical Archaeological Study (Mark Kostro Laurie A. Wilkie, Paul Farnsworth; Sampling Many Pots: An Archaeology of Memory and Tradition at a Bahamian Plantation (Grace Turner David Beriss; Black Skins, French Voices: Caribbean ethnicity and Activism in Urban France (Nadine Lefaucheur Karen E. Richman; Migration and Vodou (Natacha Giafferi Jean Moomou; Le monde des marrons du Maroni en Guyane (1772-1860: La naissance d’un peuple: Les Boni (Kenneth Bilby Jean Chapuis, Hervé Rivière; Wayana eitoponpë: (Une histoire (orale des Indiens Wayana (Dominique Tilkin Gallois Jesús Fuentes

  4. Leapfrog variants of iterative methods for linear algebra equations

    Science.gov (United States)

    Saylor, Paul E.

    1988-01-01

    Two iterative methods are considered, Richardson's method and a general second order method. For both methods, a variant of the method is derived for which only even numbered iterates are computed. The variant is called a leapfrog method. Comparisons between the conventional form of the methods and the leapfrog form are made under the assumption that the number of unknowns is large. In the case of Richardson's method, it is possible to express the final iterate in terms of only the initial approximation, a variant of the iteration called the grand-leap method. In the case of the grand-leap variant, a set of parameters is required. An algorithm is presented to compute these parameters that is related to algorithms to compute the weights and abscissas for Gaussian quadrature. General algorithms to implement the leapfrog and grand-leap methods are presented. Algorithms for the important special case of the Chebyshev method are also given.

  5. Validity and Reliability of Turkish Male Breast Self-Examination Instrument.

    Science.gov (United States)

    Erkin, Özüm; Göl, İlknur

    2018-04-01

    This study aims to measure the validity and reliability of Turkish male breast self-examination (MBSE) instrument. The methodological study was performed in 2016 at Ege University, Faculty of Nursing, İzmir, Turkey. The MBSE includes ten steps. For validity studies, face validity, content validity, and construct validity (exploratory factor analysis) were done. For reliability study, Kuder Richardson was calculated. The content validity index was found to be 0.94. Kendall W coefficient was 0.80 (p=0.551). The total variance explained by the two factors was found to be 63.24%. Kuder Richardson 21 was done for reliability study and found to be 0.97 for the instrument. The final instrument included 10 steps and two stages. The Turkish version of MBSE is a valid and reliable instrument for early diagnose. The MBSE can be used in Turkish speaking countries and cultures with two stages and 10 steps.

  6. On a multigrid method for the coupled Stokes and porous media flow problem

    Science.gov (United States)

    Luo, P.; Rodrigo, C.; Gaspar, F. J.; Oosterlee, C. W.

    2017-07-01

    The multigrid solution of coupled porous media and Stokes flow problems is considered. The Darcy equation as the saturated porous medium model is coupled to the Stokes equations by means of appropriate interface conditions. We focus on an efficient multigrid solution technique for the coupled problem, which is discretized by finite volumes on staggered grids, giving rise to a saddle point linear system. Special treatment is required regarding the discretization at the interface. An Uzawa smoother is employed in multigrid, which is a decoupled procedure based on symmetric Gauss-Seidel smoothing for velocity components and a simple Richardson iteration for the pressure field. Since a relaxation parameter is part of a Richardson iteration, Local Fourier Analysis (LFA) is applied to determine the optimal parameters. Highly satisfactory multigrid convergence is reported, and, moreover, the algorithm performs well for small values of the hydraulic conductivity and fluid viscosity, that are relevant for applications.

  7. Fourier analysis of parallel inexact Block-Jacobi splitting with transport synthetic acceleration in slab geometry

    International Nuclear Information System (INIS)

    Rosa, M.; Warsa, J. S.; Chang, J. H.

    2006-01-01

    A Fourier analysis is conducted for the discrete-ordinates (SN) approximation of the neutron transport problem solved with Richardson iteration (Source Iteration) and Richardson iteration preconditioned with Transport Synthetic Acceleration (TSA), using the Parallel Block-Jacobi (PBJ) algorithm. Both 'traditional' TSA (TTSA) and a 'modified' TSA (MTSA), in which only the scattering in the low order equations is reduced by some non-negative factor β and < 1, are considered. The results for the un-accelerated algorithm show that convergence of the PBJ algorithm can degrade. The PBJ algorithm with TTSA can be effective provided the β parameter is properly tuned for a given scattering ratio c, but is potentially unstable. Compared to TTSA, MTSA is less sensitive to the choice of β, more effective for the same computational effort (c'), and it is unconditionally stable. (authors)

  8. Numerical simulation in a two dimensional turbulent flow over a backward-facing step

    International Nuclear Information System (INIS)

    Silveira Neto, A. da; Grand, D.

    1991-01-01

    Numerical simulations of turbulent flows in complex geometries are generally restricted to the prediction of the mean flow and use semi-empirical turbulence models. The present study is devoted to the simulation of the coherence structures which develop in a flow submitted to a velocity change, downstream of a backward facing step. Two aspect ratios (height of the step over height of the channel) have been explored and the values of the Reynolds number vary from (6000 to 90000). In the isothermal case coherent structures have been obtained by the numerical simulation in the mixing layer downstream of the step. The numerical simulations provides results in fairly good agreement with available experimental results. In a second step a thermal stratification is imposed on this flow for one value of Richardson number (0.5) the coherent structures disappear downstream for increasing values of Richardson number. (author)

  9. Investigation of thermo-fluid behavior of mixed convection heat transfer of different dimples-protrusions wall patterns to heat transfer enhancement

    Science.gov (United States)

    Sobhani, M.; Behzadmehr, A.

    2018-05-01

    This study is a numerical investigation of the effect of improving heat transfer namely, modified rough (dimples and protrusions) surfaces on the mixed convective heat transfer of a turbulent flow in a horizontal tube. The effects of different dimples-protrusions arrangements on the improving the thermal performance of a rough tube are investigated at various Richardson numbers. Three dimensional governing equations are discretized by the finite-volume technique. Based on the obtained results the dimples-protrusions arrangements are modified to find a suitable configuration for which heat transfer coefficient and pressure drop to be balanced. Modified dimples-protrusions arrangements that shows higher performance is presented. Its average thermal performance 18% and 11% is higher than the other arrangements. In addition, the results show that roughening a smooth tube is more effective at the higher Richardson number.

  10. Fourier analysis of parallel block-Jacobi splitting with transport synthetic acceleration in two-dimensional geometry

    International Nuclear Information System (INIS)

    Rosa, M.; Warsa, J. S.; Chang, J. H.

    2007-01-01

    A Fourier analysis is conducted in two-dimensional (2D) Cartesian geometry for the discrete-ordinates (SN) approximation of the neutron transport problem solved with Richardson iteration (Source Iteration) and Richardson iteration preconditioned with Transport Synthetic Acceleration (TSA), using the Parallel Block-Jacobi (PBJ) algorithm. The results for the un-accelerated algorithm show that convergence of PBJ can degrade, leading in particular to stagnation of GMRES(m) in problems containing optically thin sub-domains. The results for the accelerated algorithm indicate that TSA can be used to efficiently precondition an iterative method in the optically thin case when implemented in the 'modified' version MTSA, in which only the scattering in the low order equations is reduced by some non-negative factor β<1. (authors)

  11. Treatment of Memory Disorders in Gulf War Illness with High-Definition Transcranial Direct Cortical Stimulation

    Science.gov (United States)

    2017-10-01

    Stimulation PRINCIPAL INVESTIGATOR: John Hart, Jr., M.D. RECIPIENT: The University of Texas at Dallas Richardson, TX 75080 REPORT DATE: October 2017 TYPE...including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing...Cortical Stimulation 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Dr. John Hart Jr. 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER

  12. Safety Parameter Considerations of Anodal Transcranial Direct Current Stimulation in Rats

    Science.gov (United States)

    2017-10-01

    Richardson, J.D., Baker, J.M., Rorden, C., 2011. Transcranial direct current stimulation improves naming reaction time in fluent aphasia: a...AFRL-RH-WP-TR-2017-0069 Safety parameter considerations of anodal transcranial Direct Current Stimulation in rats R. Andy McKinley...response, including the time for reviewing instructions, searching existing data sources, searching existing data sources, gathering and maintaining the

  13. Islam’s Challenge: Jihad and Terrorism

    Science.gov (United States)

    2008-12-12

    themselves as the ‘Ikhwan’ or brotherhood. They, like Mohammad who had cleansed the Kaba of its idols, destroyed Sufi shrines and sacred tombs in Mecca and...Medina, including those of the Prophet and his companions. They also destroyed the tomb of Hussain at Karbala, a major Shii holy place, an act...In the Muslim Brotherhood, he quickly emerged as the most important ideologue amid the growing confrontation with the Egyptian regime (Richardson

  14. Formaatidevaheline kunstisündmus

    Index Scriptorium Estoniae

    2003-01-01

    1. XI Kanuti gildis üritusteseeria "1+1=1" hooaja avaüritus. Esinevad kuraatorid Hanno Soans ja Andres Lõo (võrguväljaande www.looming.org tutvustus), Ieva Auzina (Läti, Haralds Elcerise film "Matti Miliuse hull manifest" (1988) jm.), Suzanne van de Ven (Kassel). A. Lõo, Kiwa, Joanne Richardson (Rumeenia), Enrico Glerean (Itaalia) esinevad heliloenguga, Ene- Liis Semper, Mark Raidpere, Jaan Toomik videoportreedega

  15. Prevent Infections During Chemotherapy

    Centers for Disease Control (CDC) Podcasts

    2011-10-24

    This podcast discusses the importance of preventing infections in cancer patients who are undergoing chemotherapy. Dr. Lisa Richardson, CDC oncologist, talks about a new Web site for cancer patients and their caregivers.  Created: 10/24/2011 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP), Division of Cancer Prevention and Control (DCPC).   Date Released: 10/24/2011.

  16. Wavelet Analysis of Near-Inertial Currents at the East Flower Garden Bank

    Science.gov (United States)

    2014-07-11

    the CW diurnal– inertial peak is minimally affected. Overall average squared vertical shear of horizontal currents ( Sh2 ¼ ð∂U=∂zÞ2þð∂V=∂zÞ2) ranged...string moorings, Section 4) were used to calculate gradient Richardson numbers, Ri ¼N2= Sh2 , where N2 is the buoyancy frequency. With a few exceptions

  17. Studies on the Biology of the Tube-Building Amphipod Microdeutopus gryllotalpa. A Model for Marine Fouling Processes.

    Science.gov (United States)

    1984-01-01

    two pairs of chelae to carry the females. But, in addition, males of different genera carry their females in different, but highly stereotyped ways...173 (1980) Shillaker. R. 0. and P. G. Moore: Tube building by the amphipods Lang. K.: The genus Oosaccus Richardson and the brood pouch Lembos...from three genera, has shown that the smaller pair is used. In addition, the use of theme gnathopods is highly stereotyped , and generic-specific

  18. Air University Library Index to Military Periodicals, Volume 43, Number 3, July-September 1992,

    Science.gov (United States)

    1992-09-01

    Publications Sdn Bhd 61A & B, 5000. Jalan Dato Haji Eusoff, Damai Complex, P.O. Box 10836, 50726 Kuala Lumpur, Malaysia . Airpower Journal (q) $9.50...Chiefs of Staff See also Malaysia tempted by cut-price MiG-29s. speak out. pot illus. Military Technology ARMY CORPS OF ENGINEERS Michael Richardson...their intense training See also PHYSICAL FITNESS regimen). James Kitfield. illus por. IDENTIFICATION OF MIUITARY Obesity and its relation to physical

  19. Treatment of Perfluorinated Compounds and Nitroaromatics by Photocatalysis in the Presence of Ultraviolet and Solar Light

    Science.gov (United States)

    2014-03-27

    fluorinated chemicals whose unique physico-chemical characteristics make them very useful for a wide range of industrial and commercial application...concerns as these compounds are toxic , extremely resistant to degradation, bioaccumulate in food chains, and can have long half-lives in humans (Richardson...significant danger to humans and the environment because of their toxicity , 6 mutagenicity and potential carcinogenicity. In fact, NACs’ environmental

  20. Fish larval transport in a macro-tidal regime: Gulf of Kachchh, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    George, G.; Vethamony, P.; Sudheesh, K.; Babu, M.T.

    management strategy for the gulf, imbibing the concepts of an ecosystem-based spatially structured approach (Richardson et al., 2010). 4. CONCLUSIONS The study shows that particle transport modelling can be an effective tool and decision support system... was carried out by Martins et al. (2007) using similar methodology. No study has been carried out so far in the Indian coastal waters to determine the influence of physical forcing on fish larvae under which they are widely dispersed or locally retained...

  1. The Origins and Development of A Cooperative Strategy for 21st Century Seapower (2015)

    Science.gov (United States)

    2017-09-01

    formal memorandum to the Commandants of the other sea services announcing the “refresh” effort. The memorandum advised that, “My staff and I will...221 ADM John Richardson would be publicly nominated as ADM Greenert’s successor in May 2015, to relieve him in September. 222 Peter M...ill- advised .250 Professor Peter Dombrowski cautioned that CS21R’s emphasis on warfighting might unintentionally contribute to a classic security

  2. The Effect of Context on Training: Is Learning Situated?

    Science.gov (United States)

    1994-09-13

    functions in quantitative reasoning. Proceedings of the Thirteenth Annual conference of the Cognitive Science Society, Hillsdale, NJ.: Lawrence Erlbaum, 1991...conceptual replication by Hendrickson and Schroeder (1941) used two levels of abstract explanation as well as a control group and found more transfer with more...learning. Annual review of psychology, 12: 243-280. Bjork, R. A. & Richardson-Klavehn, A., (1989). On the Puzzling Relationship Between Environment Context

  3. 33 CFR 334.1325 - United States Army Restricted Area, Kuluk Bay, Adak, Alaska.

    Science.gov (United States)

    2010-07-01

    ..., longitude 176°33′47.4″ W (NAD 83). (b) The regulation. (1) No vessel, person, or other craft shall enter or... 176°33′47.4″ W (NAD 83). Each buoy has a white light, flashing at 3 second intervals with a 2 nautical... such other agencies as the Director, MDA-AK, Fort Richardson, Alaska, may designate. [72 FR 65669, Nov...

  4. The OIT Times Newsletter -- Spring 2000, Vol. 3, No. 2

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, L. [ed.

    2000-04-04

    The Spring 2000 issue of OIT [Office of Industrial Technologies] Times features articles on a new ``Best Practices'' team that is facilitating motor systems and heating equipment roadmaps; combined heat and power (CHP) industry international symposium and signing compact agreement ceremony; DOE Secretary Richardson signs compact with the petroleum industry; a major steel showcase is planned for May and OIT customers speak out with what works and what doesn't.

  5. OIT Times Newsletter: Volume 3, Number 1, Winter 2000

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, L.

    1999-12-16

    The Winter 2000 edition of the OIT Times newsletter, a quarterly publication produced by the Office of Industrial Technologies, highlights the 1999 start-up projects, announces the OIT solicitation schedule for FY2000, and features the success of the Ohio diecasting showcase. One of the quarterly highlights was Secretary Richardson's presentation of a Certificate of Partnership to Malden Mills CEO Aaron Feuerstein at the dedication of the plant's new, advanced cogeneration system.

  6. Technical contribution to the project and operation of pulsed columns

    International Nuclear Information System (INIS)

    Kromek, I.B.; Ikuta, A.

    1976-01-01

    Characteristics and factors that affect the performance of pulse columms used in the purification of metals as thorium, uranium and plutonium are described. The pulse generator and the control instrumentation of these columns are also described. This report is based mainly in the works made by Richardson and Platt and adaptations realized in the project and instalation of the first compound extraction-scrub pulse column in the CEQ/IEA (Sao Paulo, Brazil) [pt

  7. Exploring New Thermal Fog and Ultra-Low Volume Technologies to Improve Indoor Control of the Dengue Vector, Aedes aegypti (Diptera: Culicidae)

    Science.gov (United States)

    2014-07-01

    Dengue Vector, Aedes aegypti (Diptera: Culicidae) JAMES F. HARWOOD,1,2 MUHAMMAD FAROOQ,1 ALEC G. RICHARDSON,1 CARL W. DOUD,1 JOHN L. PUTNAM,3 DANIEL E...vector, Aedes aegypti (L.), inside human habitations must be performed quickly and efÞciently to reduce the risk of transmission during dengue...immediate knockdown of vector populations that may lower the risk of infection and allow other suppression strategies to be implemented. KEY WORDS Aedes

  8. FY07 NRL DoD High Performance Computing Modernization Program Annual Reports

    Science.gov (United States)

    2008-09-05

    41 Mark R. Pederson ,1 Tunna Baruah,2 Steven Richardson,3 Rajendre Zope,1 and Reeshemah Allen1 1Naval Research Laboratory, Washington, DC...DC vii Acoustic Propagation in Littoral Sub-Mesoscale Model Environments.....................61 Roger M. Oba,1 Colin Shen,1 Patrick...R ea ct io n ra te , K gm ol e/ m 1 s ec ( l ef t p ic tu re ) 12 Title: Simulations of the Ionosphere and Magnetosphere Author(s): S. P

  9. A statistical mechanics approach to mixing in stratified fluids

    OpenAIRE

    Venaille , Antoine; Gostiaux , Louis; Sommeria , Joël

    2016-01-01

    Accepted for the Journal of Fluid Mechanics; Predicting how much mixing occurs when a given amount of energy is injected into a Boussinesq fluid is a longstanding problem in stratified turbulence. The huge number of degrees of freedom involved in these processes renders extremely difficult a deterministic approach to the problem. Here we present a statistical mechanics approach yielding a prediction for a cumulative, global mixing efficiency as a function of a global Richard-son number and th...

  10. A self-affine multi-fractal wave turbulence discrimination method using data from single point fast response sensors in a nocturnal atmospheric boundary layer

    OpenAIRE

    Kamada, Ray; Decaria, Alex Joseph

    1992-01-01

    We present DA, a self-affine, multi-fractal which may become the first routine wave/turbulence discriminant for time series data. Using nocturnal atmospheric data, we show the advantages of D A over self-similar fractals and standard turbulence measures such as FFTs, Richardson number, Brunt-Vaisala frequency, buoyancy length scale, variances, turbulent kinetic energy, and phase averaging. DA also shows promise in resolving "wave-break" events. Since it uses local basis functions, DA may be...

  11. Barrier height inhomogeneity in electrical transport characteristics of InGaN/GaN heterostructure interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Roul, Basanta [Materials Research Centre, Indian Institute of Science, Bangalore 560012 (India); Central Research Laboratory, Bharat Electronics, Bangalore 560013 (India); Mukundan, Shruti; Chandan, Greeshma; Mohan, Lokesh; Krupanidhi, S. B., E-mail: sbk@mrc.iisc.ernet.in [Materials Research Centre, Indian Institute of Science, Bangalore 560012 (India)

    2015-03-15

    We have grown InGaN/GaN heterostructures using plasma-assisted molecular beam epitaxy and studied the temperature dependent electrical transport characteristics. The barrier height (φ{sub b}) and the ideally factor (η) estimated using thermionic emission model were found to be temperature dependent. The conventional Richardson plot of ln(J{sub s}/T{sup 2}) versus 1/kT showed two temperature regions (region-I: 400–500 K and region-II: 200–350 K) and it provides Richardson constants (A{sup ∗}) which are much lower than the theoretical value of GaN. The observed variation in the barrier height and the presence of two temperature regions were attributed to spatial barrier inhomogeneities at the heterojunction interface and was explained by assuming a double Gaussian distribution of barrier heights with mean barrier height values 1.61 and 1.21 eV with standard deviation (σ{sub s}{sup 2}) of 0.044 and 0.022 V, respectively. The modified Richardson plot of ln(J{sub s}/T{sup 2}) − (q{sup 2}σ{sub s}{sup 2}/2k{sup 2}T{sup 2}) versus 1/kT for two temperature regions gave mean barrier height values as 1.61 eV and 1.22 eV with Richardson constants (A{sup ∗}) values 25.5 Acm{sup −2}K{sup −2} and 43.9 Acm{sup −2}K{sup −2}, respectively, which are very close to the theoretical value. The observed barrier height inhomogeneities were interpreted on the basis of the existence of a double Gaussian distribution of barrier heights at the interface.

  12. Fluidisation and dispersion behaviour of small high density pellicular expanded bed adsorbents

    DEFF Research Database (Denmark)

    Theodossiou, Irini; Elsner, H.D.; Thomas, Owen R. T.

    2002-01-01

    correlation for characterisation of expanded bed systems is questioned. Residence time distribution studies using acetone tracers, demonstrated that in comparison to existing commercial supports, the small pellicular prototype materials generally possessed far superior hydrodynamic properties, which augurs......, fluidisation behaviour was poorly predicted from the Richardson-Zaki correlation, with experimentally determined values of the expansion index being considerably higher than the theoretical values. The reasons for these discrepancies are discussed in detail and the validity of applying this widely used...

  13. Chlorinated hydrocarbon pesticides and polychlorinated biphenyls in sediment cores from San Francisco Bay

    Science.gov (United States)

    Venkatesan, M.I.; De Leon, R. P.; VanGeen, A.; Luoma, S.N.

    1999-01-01

    Sediment cores of known chronology from Richardson and San Pablo Bays in San Francisco Bay, CA, were analyzed for a suite of chlorinated hydrocarbon pesticides and polychlorinated biphenyls to reconstruct a historic record of inputs. Total DDTs (DDT = 2,4'- and 4,4'-dichlorodiphenyltrichloroethane and the metabolites, 2,4'- and 4,4'-DDE, -DDD) range in concentration from 4-21 ng/g and constitute a major fraction (> 84%) of the total pesticides in the top 70 cm of Richardson Bay sediment. A subsurface maximum corresponds to a peak deposition date of 1969-1974. The first measurable DDT levels are found in sediment deposited in the late 1930's. The higher DDT inventory in the San Pablo relative to the Richardson Bay core probably reflects the greater proximity of San Pablo Bay to agricultural activities in the watershed of the Sacramento and San Joaquin rivers. Total polychlorinated biphenyls (PCBs) occur at comparable levels in the two Bays (inventories in San Pablo Bay are about a factor of four higher in the last four decades than in Richardson Bay, suggesting a distribution of inputs not as strongly weighed towards the upper reaches of the estuary as DDTs. The shallower subsurface maximum in PCBs compared to DDT in the San Pablo Bay core is consistent with the imposition of drastic source control measures four these constituents in 1970 and 1977 respectively. The observed decline in DDT and PCB levels towards the surface of both cores is consistent with a dramatic drop in the input of these pollutants once the effect of sediment resuspension and mixing is taken into account.

  14. Restoration in North America: The story of a library

    Directory of Open Access Journals (Sweden)

    Iñaki Ozcáriz

    1997-05-01

    Full Text Available In this article, we present as an introduction the situation of restoration in the United States and, as a specific example, the successive reforms and amplifications of a small library by Henry H. Richardson, whose history reflects significant phenomena connected with restoration in this country. The importance of the author and his architectural expertise made this one of the most admired buildings of its time and one whose influence has been decisive.

  15. Pricing and simulation for real estate index options: Radial basis point interpolation

    Science.gov (United States)

    Gong, Pu; Zou, Dong; Wang, Jiayue

    2018-06-01

    This study employs the meshfree radial basis point interpolation (RBPI) for pricing real estate derivatives contingent on real estate index. This method combines radial and polynomial basis functions, which can guarantee the interpolation scheme with Kronecker property and effectively improve accuracy. An exponential change of variables, a mesh refinement algorithm and the Richardson extrapolation are employed in this study to implement the RBPI. Numerical results are presented to examine the computational efficiency and accuracy of our method.

  16. Quark mean field theory and consistency with nuclear matter

    International Nuclear Information System (INIS)

    Dey, J.; Tomio, L.; Dey, M.; Frederico, T.

    1989-01-01

    1/N c expansion in QCD (with N c the number of colours) suggests using a potential from meson sector (e.g. Richardson) for baryons. For light quarks a σ field has to be introduced to ensure chiral symmetry breaking ( χ SB). It is found that nuclear matter properties can be used to pin down the χ SB-modelling. All masses, M Ν , m σ , m ω are found to scale with density. The equations are solved self consistently. (author)

  17. An improved model for estimating fractal structure of silica nano-agglomerates in a vibro-fluidized bed

    OpenAIRE

    A Esmailpour; N Mostoufi; R Zarghami

    2016-01-01

    A study has been conducted to determine the effects of operating conditions such as vibration frequency, vibration amplitude on the fractal structure of silica (SiO2) nanoparticle agglomerate in a vibro-fluidized bed. An improved model was proposed by assimilation of fractal theory, Richardson-Zaki equation and mass balance. This model has been developed to predict the properties of nanoparticle agglomerate, such as fractal dimension and its size. It has been found out the vibration intensity...

  18. Some effects of horizontal discretization on linear baroclinic and symmetric instabilities

    Science.gov (United States)

    Barham, William; Bachman, Scott; Grooms, Ian

    2018-05-01

    The effects of horizontal discretization on linear baroclinic and symmetric instabilities are investigated by analyzing the behavior of the hydrostatic Eady problem in ocean models on the B and C grids. On the C grid a spurious baroclinic instability appears at small wavelengths. This instability does not disappear as the grid scale decreases; instead, it simply moves to smaller horizontal scales. The peak growth rate of the spurious instability is independent of the grid scale as the latter decreases. It is equal to cf /√{Ri} where Ri is the balanced Richardson number, f is the Coriolis parameter, and c is a nondimensional constant that depends on the Richardson number. As the Richardson number increases c increases towards an upper bound of approximately 1/2; for large Richardson numbers the spurious instability is faster than the Eady instability. To suppress the spurious instability it is recommended to use fourth-order centered tracer advection along with biharmonic viscosity and diffusion with coefficients (Δx) 4 f /(32√{Ri}) or larger where Δx is the grid scale. On the B grid, the growth rates of baroclinic and symmetric instabilities are too small, and converge upwards towards the correct values as the grid scale decreases; no spurious instabilities are observed. In B grid models at eddy-permitting resolution, the reduced growth rate of baroclinic instability may contribute to partially-resolved eddies being too weak. On the C grid the growth rate of symmetric instability is better (larger) than on the B grid, and converges upwards towards the correct value as the grid scale decreases.

  19. Analysis of a Small Vigorous Mesoscale Convective System in a Low-Shear Environment. Pt. 1; Formation, Echo Structure and Lightning Behavior

    Science.gov (United States)

    Knupp, Kevin; Geerts, Bart; Goodman, Steven J.

    1997-01-01

    The precipitation output was highly variable due to the transient nature of the intense convective elements. This result is attributed to the high Richardson number (175) of the environment, which is much higher than that of the typical MCS environment. The development of the stratiform precipitation was accomplished locally (in situ), and not be advection of from the convective region. In situ charging of the stratiform region is also supported by the observations.

  20. The Oblique Basis Method from an Engineering Point of View

    International Nuclear Information System (INIS)

    Gueorguiev, V G

    2012-01-01

    The oblique basis method is reviewed from engineering point of view related to vibration and control theory. Examples are used to demonstrate and relate the oblique basis in nuclear physics to the equivalent mathematical problems in vibration theory. The mathematical techniques, such as principal coordinates and root locus, used by vibration and control theory engineers are shown to be relevant to the Richardson - Gaudin pairing-like problems in nuclear physics.

  1. Weighing Evidence: The Design and Comparison of Probability Thought Experiments.

    Science.gov (United States)

    1983-06-01

    ics and Other Logical Essays, R. G. Braithwaite (ed.), Routledge and Kegan Paul. Richardson, H. R., and Stone, L. D.: 1971, ’Operations analysis...Systems Department ONR Detachment Code 35 1030 East Green Street Naval Underwater Systems Center Pasadena, CA 91106 Newport, RI 02840 CDR James Offutt...Officer-in-Charge Human Factors Department ONR Detachment Code N-71 1030 East Green Street Naval Training Equipment Center Pasadena, CA 91106 Orlando

  2. The Narcissim of Baron Dominique-Jean Larrey

    Science.gov (United States)

    2015-04-01

    Narcissism and Approach–Avoidance Motivation.” Personality and Social Psychology Bulletin 34, no. 7 (July 2008): 1015. SAGE Journals , http...Social Psychology Bulletin 34, no. 7 (July 2008): 1006. SAGE Journals , http://psp.sagepub.com/. 51. Robert G. Richardson, Larrey: Surgeon to...1004-1017. SAGE Journals , http://psp.sagepub.com/ (accessed March 22, 2015). Howard, Martin R., Napoleon’s Doctors: The Medical Services of the

  3. Evaluation of Metals Release from Oxidation of Fly Ash during Dredging of the Emory River, TN

    Science.gov (United States)

    2011-08-01

    Tennessee Valley Authority Kingston Fossil Plant (U.S. Environmental Protection Agency (USEPA) 2009). Remediation and recovery efforts for this event are...Acclimation-induced changes in toxicity of arsenic and cyanide to rainbow trout, Salmo gairdneri Richardson. J Fish Biol. 18: 579- 589. Dobbs, M. G...Dispersion potential of selected Iowa lake sediments as influenced by dissolved and solid-phase constituents. Clean 36: 201-208. McGeachy, S. M., and

  4. An Assessment of the Available Evidence on the Returns to Military Training

    Science.gov (United States)

    1977-07-01

    Hanushek Kassing McCall and Wallace Mason (1970) Nathan Associates Weinstein et al. Richardson (1967) Thorndike and Hagen (1957) u.s...Biderman Cutright Freeman Hanushek Kassing McCall and Wallace Mason (1970) Primary Purpose of the Study Analyze the vocational readjustment...that veterans do not receive a positive economic return from military voca- tional training. Mason (1970), Hanushek , Cutright, and Kassing reach

  5. Enhancement accuracy of approximated solutions of the nonlinear singular integral equations of Chew-Low type

    International Nuclear Information System (INIS)

    Zhidkov, E.P.; Nguen Mong; Khoromskij, B.N.

    1979-01-01

    The ways of enhancement of the accuracy of approximate solutions of the Chew-Low type equation are considered. Difference schemes are proposed which allow one to obtain solution expansion in degrees of lattice step. On the basis of the expansion by the Richardson method the refinement of approximated solutions is made. Besides, the iteration process is constructed which reduces immediately to the solution of enhanced accuracy. The efficiency of the methods proposed is illustrated by numerical examples

  6. The Prado Dam and Reservoir, Riverside and San Bernardino Counties, California

    Science.gov (United States)

    1989-10-31

    County’s Renewed Push for Water Conservation ............. 72 Riverside County Reaction , Late 1940s ........................... 76 Development of...is sloped to the typography to reduce erosion below the concrete-lined section. The emergency spillway had a designed pond elevation of 556 feet, and a...means of pumping water downstream (Nick Richardson, personal communication 1989). 75 4R CL 44- t,, v I. 76 Riverside County Reaction , Late 1940s The

  7. Contact Between Birth and Adoptive Families During the First Year Post-Placement: Perspectives of Lesbian, Gay, and Heterosexual Parents

    OpenAIRE

    Farr, Rachel H.; Goldberg, Abbie E.

    2014-01-01

    Despite growing visibility of lesbian- and gay-parent adoption, only one qualitative study has examined birth family contact among adoptive families with lesbian and gay parents (Goldberg, Kinkler, Richardson, & Downing, 2011). We studied adoptive parents’ (34 lesbian, 32 gay, and 37 heterosexual; N = 103 families) perspectives of birth family contact across the first year post-placement. Using questionnaire and interview data, we found few differences in openness dynamics by parental sexual ...

  8. Fifteenth LAMPF users group meeting

    International Nuclear Information System (INIS)

    Cochran, D.R.F.

    1982-03-01

    The Fifteenth LAMPF Users Group Meeting was held November 2-3, 1981 at the Clinton P. Anderson Meson Physical Facility. The program of papers scheduled to be presented was amended to include a Report from Washington by Clarence R. Richardson, US Department of Energy. The general meeting ended with a round-table working group discussion concerning the Planning for a Kaon Factory. Individual items from the meeting were prepared separately for the data base

  9. Estimating the planetary boundary layer height from radiosonde and doppler lidar measurements in the city of São Paulo - Brazil

    Science.gov (United States)

    Marques, Márcia T. A.; Moreira, Gregori de A.; Pinero, Maciel; Oliveira, Amauri P.; Landulfo, Eduardo

    2018-04-01

    This study aims to compare the planetary boundary layer height (PBLH) values estimated by radiosonde data through the bulk Richardson number (BRN) method and by Doppler lidar measurements through the Carrier to Noise Ratio (CNR) method, which corresponds to the maximum of the variance of CNR profile. The measurement campaign was carried during the summer of 2015/2016 in the city of São Paulo. Despite the conceptual difference between these methods, the results show great agreement between them.

  10. An experimental study on the near-source region of lazy turbulent plumes

    Science.gov (United States)

    Ciriello, Francesco; Hunt, Gary R.

    2017-11-01

    The near-source region of a `lazy' turbulent buoyant plume issuing from a circular source is examined for source Richardson numbers in the range of 101 to 107. New data is acquired for the radial contraction and streamwise variation of volume flux through an experimental programme of dye visualisations and particle image velocimetry. This data reveals the limited applicability of traditional entrainment laws used in integral modelling approaches for the description of the near-source region for these source Richardson numbers. A revised entrainment function is proposed, based on which we introduce a classification of plume behaviour whereby the degree of `laziness' may be expressed in terms of the excess dilution that occurs compared to a `pure' constant Richardson number plume. The increased entrainment measured in lazy plumes is attributed to Rayleigh-Taylor instabilities developing along the contraction of the plume which promote the additional engulfment of ambient fluid into the plume. This work was funded by an EPSRC Industial Case Award sponsored by Dyson Technology Ltd. Special thanks go to the members of the Dyson Environmental Control Group that regularly visit us in Cambridge for discussions about our work.

  11. Pulling it all together: the self-consistent distribution of neutral tori in Saturn's Magnetosphere based on all Cassini observations

    Science.gov (United States)

    Smith, H. T.; Richardson, J. D.

    2017-12-01

    Saturn's magnetosphere is unique in that the plumes from the small icy moon, Enceladus, serve at the primary source for heavy particles in Saturn's magnetosphere. The resulting co-orbiting neutral particles interact with ions, electrons, photons and other neutral particles to generate separate H2O, OH and O tori. Characterization of these toroidal distributions is essential for understanding Saturn magnetospheric sources, composition and dynamics. Unfortunately, limited direct observations of these features are available so modeling is required. A significant modeling challenge involves ensuring that either the plasma and neutral particle populations are not simply input conditions but can provide feedback to each population (i.e. are self-consistent). Jurac and Richardson (2005) executed such a self-consistent model however this research was performed prior to the return of Cassini data. In a similar fashion, we have coupled a 3-D neutral particle model (Smith et al. 2004, 2005, 2006, 2007, 2009, 2010) with a plasma transport model (Richardson 1998; Richardson & Jurac 2004) to develop a self-consistent model which is constrained by all available Cassini observations and current findings on Saturn's magnetosphere and the Enceladus plume source resulting in much more accurate neutral particle distributions. We present a new self-consistent model of the distribution of the Enceladus-generated neutral tori that is validated by all available observations. We also discuss the implications for source rate and variability.

  12. Particle–hole duality, integrability, and Russian doll BCS model

    Energy Technology Data Exchange (ETDEWEB)

    Bork, L.V. [Center for Fundamental and Applied Research, N. L. Dukhov All-Russia Research Institute of Automatics, 127055 Moscow (Russian Federation); Institute for Theoretical and Experimental Physics, 117218 Moscow (Russian Federation); Pogosov, W.V., E-mail: walter.pogosov@gmail.com [Center for Fundamental and Applied Research, N. L. Dukhov All-Russia Research Institute of Automatics, 127055 Moscow (Russian Federation); Institute for Theoretical and Applied Electrodynamics, Russian Academy of Sciences, 125412 Moscow (Russian Federation); Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700 (Russian Federation)

    2015-08-15

    We address a generalized Richardson model (Russian doll BCS model), which is characterized by the breaking of time-reversal symmetry. This model is known to be exactly solvable and integrable. We point out that the Russian doll BCS model, on the level of Hamiltonian, is also particle–hole symmetric. This implies that the same state can be expressed both in the particle and hole representations with two different sets of Bethe roots. We then derive exact relations between Bethe roots in the two representations, which can hardly be obtained staying on the level of Bethe equations. In a quasi-classical limit, similar identities for usual Richardson model, known from literature, are recovered from our results. We also show that these relations for Richardson roots take a remarkably simple form at half-filling and for a symmetric with respect to the middle of the interaction band distribution of one-body energy levels, since, in this special case, the rapidities in the particle and hole representations up to the translation satisfy the same system of equations.

  13. Current-voltage temperature characteristics of Au/n-Ge (1 0 0) Schottky diodes

    Energy Technology Data Exchange (ETDEWEB)

    Chawanda, Albert, E-mail: albert.chawanda@up.ac.za [Midlands State University, Bag 9055 Gweru (Zimbabwe); University of Pretoria, 0002 Pretoria (South Africa); Mtangi, Wilbert; Auret, Francois D; Nel, Jacqueline [University of Pretoria, 0002 Pretoria (South Africa); Nyamhere, Cloud [Nelson Mandela Metropolitan University, Port Elizabeth (South Africa); Diale, Mmantsae [University of Pretoria, 0002 Pretoria (South Africa)

    2012-05-15

    The variation in electrical characteristics of Au/n-Ge (1 0 0) Schottky contacts have been systematically investigated as a function of temperature using current-voltage (I-V) measurements in the temperature range 140-300 K. The I-V characteristics of the diodes indicate very strong temperature dependence. While the ideality factor n decreases, the zero-bias Schottky barrier height (SBH) ({Phi}{sub B}) increases with the increasing temperature. The I-V characteristics are analyzed using the thermionic emission (TE) model and the assumption of a Gaussian distribution of the barrier heights due to barrier inhomogeneities at the metal-semiconductor interface. The zero-bias barrier height {Phi}{sub B} vs. 1/2 kT plot has been used to show the evidence of a Gaussian distribution of barrier heights and values of {Phi}{sub B}=0.615 eV and standard deviation {sigma}{sub s0}=0.0858 eV for the mean barrier height and zero-bias standard deviation have been obtained from this plot, respectively. The Richardson constant and the mean barrier height from the modified Richardson plot were obtained as 1.37 A cm{sup -2} K{sup -2} and 0.639 eV, respectively. This Richardson constant is much smaller than the reported of 50 A cm{sup -2} K{sup -2}. This may be due to greater inhomogeneities at the interface.

  14. Mixed convection in inclined lid driven cavity by Lattice Boltzmann Method and heat flux boundary condition

    International Nuclear Information System (INIS)

    D'Orazio, A; Karimipour, A; Nezhad, A H; Shirani, E

    2014-01-01

    Laminar mixed convective heat transfer in two-dimensional rectangular inclined driven cavity is studied numerically by means of a double population thermal Lattice Boltzmann method. Through the top moving lid the heat flux enters the cavity whereas it leaves the system through the bottom wall; side walls are adiabatic. The counter-slip internal energy density boundary condition, able to simulate an imposed non zero heat flux at the wall, is applied, in order to demonstrate that it can be effectively used to simulate heat transfer phenomena also in case of moving walls. Results are analyzed over a range of the Richardson numbers and tilting angles of the enclosure, encompassing the dominating forced convection, mixed convection, and dominating natural convection flow regimes. As expected, heat transfer rate increases as increases the inclination angle, but this effect is significant for higher Richardson numbers, when buoyancy forces dominate the problem; for horizontal cavity, average Nusselt number decreases with the increase of Richardson number because of the stratified field configuration

  15. Ideal, nonideal, and no-marker variables: The confirmatory factor analysis (CFA) marker technique works when it matters.

    Science.gov (United States)

    Williams, Larry J; O'Boyle, Ernest H

    2015-09-01

    A persistent concern in the management and applied psychology literature is the effect of common method variance on observed relations among variables. Recent work (i.e., Richardson, Simmering, & Sturman, 2009) evaluated 3 analytical approaches to controlling for common method variance, including the confirmatory factor analysis (CFA) marker technique. Their findings indicated significant problems with this technique, especially with nonideal marker variables (those with theoretical relations with substantive variables). Based on their simulation results, Richardson et al. concluded that not correcting for method variance provides more accurate estimates than using the CFA marker technique. We reexamined the effects of using marker variables in a simulation study and found the degree of error in estimates of a substantive factor correlation was relatively small in most cases, and much smaller than error associated with making no correction. Further, in instances in which the error was large, the correlations between the marker and substantive scales were higher than that found in organizational research with marker variables. We conclude that in most practical settings, the CFA marker technique yields parameter estimates close to their true values, and the criticisms made by Richardson et al. are overstated. (c) 2015 APA, all rights reserved).

  16. The distribution of Enceladus water-group neutrals in Saturn’s Magnetosphere

    Science.gov (United States)

    Smith, Howard T.; Richardson, John D.

    2017-10-01

    Saturn’s magnetosphere is unique in that the plumes from the small icy moon, Enceladus, serve at the primary source for heavy particles in Saturn’s magnetosphere. The resulting co-orbiting neutral particles interact with ions, electrons, photons and other neutral particles to generate separate H2O, OH and O tori. Characterization of these toroidal distributions is essential for understanding Saturn magnetospheric sources, composition and dynamics. Unfortunately, limited direct observations of these features are available so modeling is required. A significant modeling challenge involves ensuring that either the plasma and neutral particle populations are not simply input conditions but can provide feedback to each population (i.e. are self-consistent). Jurac and Richardson (2005) executed such a self-consistent model however this research was performed prior to the return of Cassini data. In a similar fashion, we have coupled a 3-D neutral particle model (Smith et al. 2004, 2005, 2006, 2007, 2009, 2010) with a plasma transport model (Richardson 1998; Richardson & Jurac 2004) to develop a self-consistent model which is constrained by all available Cassini observations and current findings on Saturn’s magnetosphere and the Enceladus plume source resulting in much more accurate neutral particle distributions. Here a new self-consistent model of the distribution of the Enceladus-generated neutral tori that is validated by all available observations. We also discuss the implications for source rate and variability.

  17. Turbulent fluxes in stably stratified boundary layers

    International Nuclear Information System (INIS)

    L'vov, Victor S; Procaccia, Itamar; Rudenko, Oleksii

    2008-01-01

    We present here an extended version of an invited talk we gave at the international conference 'Turbulent Mixing and Beyond'. The dynamical and statistical description of stably stratified turbulent boundary layers with the important example of the stable atmospheric boundary layer in mind is addressed. Traditional approaches to this problem, based on the profiles of mean quantities, velocity second-order correlations and dimensional estimates of the turbulent thermal flux, run into a well-known difficulty, predicting the suppression of turbulence at a small critical value of the Richardson number, in contradiction to observations. Phenomenological attempts to overcome this problem suffer from various theoretical inconsistencies. Here, we present an approach taking into full account all the second-order statistics, which allows us to respect the conservation of total mechanical energy. The analysis culminates in an analytic solution of the profiles of all mean quantities and all second-order correlations, removing the unphysical predictions of previous theories. We propose that the approach taken here is sufficient to describe the lower parts of the atmospheric boundary layer, as long as the Richardson number does not exceed an order of unity. For much higher Richardson numbers, the physics may change qualitatively, requiring careful consideration of the potential Kelvin-Helmoholtz waves and their interaction with the vortical turbulence.

  18. On the possibility of wave-induced chaos in a sheared, stably stratified fluid layer

    Directory of Open Access Journals (Sweden)

    W. B. Zimmermann

    1994-01-01

    Full Text Available Shear flow in a stable stratification provides a waveguide for internal gravity waves. In the inviscid approximation, internal gravity waves are known to be unstable below a threshold in Richardson number. However, in a viscous fluid, at low enough Reynolds number, this threshold recedes to Ri = 0. Nevertheless, even the slightest viscosity strongly damps internal gravity waves when the Richardson number is small (shear forces dominate buoyant forces. In this paper we address the dynamics that approximately govern wave propagation when the Richardson number is small and the fluid is viscous. When Ri ξ = λ1A + λ2Aξξ + λ3Aξξξ + λ4AAξ + b(ξ where ξ is the coordinate of the rest frame of the passing temperature wave whose horizontal profile is b(ξ. The parameters λi are constants that depend on the Reynolds number. The above dynamical system is know to have limit cycle and chaotic attrators when forcing is sinusoidal and wave attenuation negligible.

  19. Mixed Convection of Variable Properties Al2O3-EG-Water Nanofluid in a Two-Dimensional Lid-Driven Enclosure

    Directory of Open Access Journals (Sweden)

    G.A. Sheikhzadeh

    2013-07-01

    Full Text Available In this paper, mixed convection of Al2O3-EG-Water nanofluid in a square lid-driven enclosure is investigated numerically. The focus of this study is on the effects of variable thermophysical properties of the nanofluid on the heat transfer characteristics. The top moving and the bottom stationary horizontal walls are insulated, while the vertical walls are kept at different constant temperatures. The study is carried out for Richardson numbers of 0.01–1000, the solid volume fractions of 0–0.05 and the Grashof number of 104. The transport equations are solved numerically with a finite volume approach using the SIMPLER algorithm. The results show that the Nusselt number is mainly affected by the viscosity, density and conductivity variations. For low Richardson numbers, although viscosity increases by increasing the nanoparticles volume fraction, due to high intensity convection of enhanced conductivity nanofluid, the average Nusselt number increases for both constant and variable cases. However, for high Richardson numbers, as the volume fraction of nanoparticles increases heat transfer enhancement occurs for the constant properties cases but deterioration in heat transfer occurs for the variable properties cases. The distinction is due to underestimation of viscosity of the nanofluid by the constant viscosity model in the constant properties cases and states important effects of temperature dependency of thermophysical properties, in particular the viscosity distribution in the domain.

  20. Turbulence and Mixing in a Shallow Shelf Sea From Underwater Gliders

    Science.gov (United States)

    Schultze, Larissa K. P.; Merckelbach, Lucas M.; Carpenter, Jeffrey R.

    2017-11-01

    The seasonal thermocline in shallow shelf seas acts as a natural barrier for boundary-generated turbulence, damping scalar transport to the upper regions of the water column and controlling primary production to a certain extent. To better understand turbulence and mixing conditions within the thermocline, two unique 12 and 17 day data sets with continuous measurements of the dissipation rate of turbulent kinetic energy (ɛ) collected by autonomous underwater gliders under stratified to well-mixed conditions are presented. A highly intermittent ɛ signal was observed in the stratified thermocline region, which was mainly characterized by quiescent flow (turbulent activity index below 7). The rate of diapycnal mixing remained relatively constant for the majority of the time with peaks of higher fluxes that were responsible for much of the increase in bottom mixed layer temperature. The water column stayed predominantly strongly stratified, with a bulk Richardson number across the thermocline well above 2. A positive relationship between the intensity of turbulence, shear, and stratification was found. The trend between turbulence levels and the bulk Richardson number was relatively weak but suggests that ɛ increases as the bulk Richardson number approaches 1. The results also highlight the interpretation difficulties in both quantifying turbulent thermocline fluxes as well as the responsible mechanisms.

  1. Classification of SDN distributed controller approaches: a brief overview

    CSIR Research Space (South Africa)

    Nkosi, M

    2016-11-01

    Full Text Available - OpenFlow capable devices. In TERENA Networking Conference (pp. 1- 15). [5] Richardson, L., Amundsen, M. and Ruby, S., 2013. RESTful Web APIs. " O'Reilly Media, Inc.". [6] Kreutz, D., Ramos, F.M., Verissimo, P.E., Rothenberg, C.E., Azodolmolky, S...], OpenFlow is the most supported in the commercial SDN switches/routers [5]. The control plane support the use of different southbound APIs. This is to allow the use of different devices and protocols in a network [6]. To communicate...

  2. Robust Speech Processing & Recognition: Speaker ID, Language ID, Speech Recognition/Keyword Spotting, Diarization/Co-Channel/Environmental Characterization, Speaker State Assessment

    Science.gov (United States)

    2015-10-01

    Dallas Erik Jonsson School of Engineering & Computer Science EC32 P.O. Box 830688 Richardson, Texas 75083-0688 8. PERFORMING ORGANIZATION REPORT...87 4.3 Whisper Based Processing for ASR ………………………………………….…. 92 5.0 Task 5: SPEAKER STATE ASSESSMENT/ ENVIROMENTAL SNIFFING (SSA/ENVS...Dec. 7-10, 2014 [3] S. Amuda, H. Boril, A. Sangwan, J.H.L. Hansen, T.S. Ibiyemi, “ Engineering analysis and recognition of Nigerian English: An

  3. Linearized potential vorticity mode and its role in transition to baroclinic instability

    International Nuclear Information System (INIS)

    Pieri, Alexandre; Salhi, Aziz; Cambon, Claude; Godeferd, Fabien

    2011-01-01

    Stratified shear flows have been studied using Rapid Distortion Theory (RDT) and DNS. If this flow is in addition subjected to vertical rotation, a slaved horizontal stratification is forced and baroclinic instability can occur. In this context, the RDT analysis shows an extention of the unstable domain up to a Richardson number Ri of 1. This work is completed here with new results on transition to baroclinic instability. Especially, the role of k x ≈ 0 modes (small streamwise wavenumbers) and the importance of coupling with the potential vorticity mode u (Ω pot ) is shown to be determinant for dramatic transient growth at intermediate times.

  4. Water simulation of sodium reactors

    International Nuclear Information System (INIS)

    Grewal, S.S.; Gluekler, E.L.

    1981-01-01

    The thermal hydraulic simulation of a large sodium reactor by a scaled water model is examined. The Richardson Number, friction coefficient and the Peclet Number can be closely matched with the water system at full power and the similarity is retained for buoyancy driven flows. The simulation of thermal-hydraulic conditions in a reactor vessel provided by a scaled water experiment is better than that by a scaled sodium test. Results from a correctly scaled water test can be tentatively extrapolated to a full size sodium system

  5. A Remarkable Collection of Rare Scriptures in a Small University Library Setting

    Directory of Open Access Journals (Sweden)

    Teresa Cardin Ellis

    2013-04-01

    Full Text Available Hardin-Simmons University was given two remarkable collections of rare Bibles and a Sefer Torah with the expressed desire of the donors for the collections to be shared with students, faculty and other constituencies of the university's Richardson Library. The library has tried to fulfill this request while attempting to preserve these treasures for future generations. As small university, without a trained archivist or preservationist, we have utilized resources outside our library and contiue to pursue sources to assist us in the maintenance of these special collections while still engaging them in the educational process.

  6. Scoping Summary Report, Los Angeles AFB, California. Air Force Base Closure and Realignment Environmental Impact Analysis Process Support

    Science.gov (United States)

    1990-07-01

    Mexico 87123 Dayton, Ohio 45402 * Richard A. Lampson Butch Maki Hydro Conduit Corp. Congressman Bill Richardson - 4801 Yucatan N.E. 548 Agua Fria...some chile con queso; however, that would be too much, and I think that might be considered a bribe. The Mayor asked me to convey his regrets. He’s tied...that God sends you here. Also, the small momento that Loretta is giving you, which is our state symbol, has a chile on it; and that’s to remind you

  7. Renormalization scheme-dependence of perturbative quantum chromodynamics corrections to quarkonia

    International Nuclear Information System (INIS)

    Dentamaro, A.V.

    1985-05-01

    QCD radiative corrections to physical quantities are studied using Stevenson's principle of minimal sensitivity (PMS) to define the renormalization. We examine several naive potentials (Cornell group, power law and logarithmic), as well as the more sophisticated Richardson model in order to determine the spectra for the non-relativistic heavy charmonium and bottomonium systems. Predictions are made for the values of hyperfine splittings, leptonic and hadronic decay widths and E1 transition rates for these families of mesons. It is shown that good agreement with experimental data may be achieved by using a constant value of Λ/sub QCD/, which is determined by the PMS scheme and the potential model

  8. Experimental study of relative, turbulent diffusion

    DEFF Research Database (Denmark)

    Mann, J.; Ott, Søren; Andersen, J.S.

    1999-01-01

    The purpose is to study relative turbulent diffusion under controlled, reproducible conditions in the laboratory in order to estimate the constant C in Richardson-Obukhov's law. We get C #approx# 0.4 -- 0.6. We furthermore measure the distance-neighbourfunction, which is the probability density...... system with two computers each equipped with a frame grabber card. In the search for the best experimentalmethods we have revised the concept of local homogeneity and derived a law for the velocity--acceleration structure function. A second by-product of this effort is a relatively simple derivation...

  9. Theory of thermionic emission from a two-dimensional conductor and its application to a graphene-semiconductor Schottky junction

    Science.gov (United States)

    Trushin, Maxim

    2018-04-01

    The standard theory of thermionic emission developed for three-dimensional semiconductors does not apply to two-dimensional materials even for making qualitative predictions because of the vanishing out-of-plane quasiparticle velocity. This study reveals the fundamental origin of the out-of-plane charge carrier motion in a two-dimensional conductor due to the finite quasiparticle lifetime and huge uncertainty of the out-of-plane momentum. The theory is applied to a Schottky junction between graphene and a bulk semiconductor to derive a thermionic constant, which, in contrast to the conventional Richardson constant, is determined by the Schottky barrier height and Fermi level in graphene.

  10. Um estudo sobre a validade de construto da Parent-Child Conflict Tactics Scale (CTSPC em uma amostra populacional urbana do Nordeste brasileiro A study on the construct validity of the Parent-Child Conflict Tactics Scale (CTSPC in an urban population in Northeast Brazil

    Directory of Open Access Journals (Sweden)

    Camila Barreto Bonfim

    2011-11-01

    Full Text Available A Parent-Child Conflict Tactics Scale (CTSPC tem sido um dos instrumentos mais utilizados internacionalmente para investigação da violência doméstica contra a criança, porém o uso segmentado de suas escalas tem se mostrado inadequado devido à complexidade do fenômeno. Esta pesquisa tem por objetivo estudar a estrutura fatorial das escalas da CTSPC em uma amostra populacional urbana do Nordeste brasileiro, sendo conduzido um estudo transversal com 1.370 crianças de uma coorte em Salvador, Bahia. Realizou-se análise fatorial com rotação oblíqua promax e calculou-se o coeficiente Kuder-Richardson. A análise fatorial revelou uma distribuição dos itens nos fatores de forma diferente da proposta do instrumento original. Verificou-se um perfil gradativo de violência em cada fator. Os valores obtidos para o Kuder-Richardson foram 0,63 para o Fator 1, 0,59 para o Fator 2 e 0,42 para o Fator 3. Os itens comportaram-se de forma diferente da proposta original do instrumento, corroborando estudos internacionais. Baseando-se nessas evidências, é possível propor um redimensionamento da CTSPC.The Parent-Child Conflict Tactics Scale (CTSPC is one of the most widely used instruments in the world for investigating domestic violence against children, but targeted use has proven inadequate given the phenomenon's complexity. This study focused on the factor structure of CTSPC scales in an urban population in Northeast Brazil. We conducted a cross-sectional study in a cohort of 1,370 children in Salvador, Bahia State. Factor analysis with promax oblique rotation was performed, and the Kuder-Richardson coefficient was calculated. Factor analysis showed a different distribution of items in the factors as compared to the original instrument. Violence showed a gradual profile in each factor. The Kuder-Richardson coefficient was 0.63 for factor 1, 0.59 for factor 2, and 0.42 for factor 3. The items behaved differently from the original instrument

  11. Quantifying linguistic coordination

    DEFF Research Database (Denmark)

    Fusaroli, Riccardo; Tylén, Kristian

    task (Bahrami et al 2010, Fusaroli et al. 2012) we extend to linguistic coordination dynamical measures of recurrence employed in the analysis of sensorimotor coordination (such as heart-rate (Konvalinka et al 2011), postural sway (Shockley 2005) and eye-movements (Dale, Richardson and Kirkham 2012......). We employ nominal recurrence analysis (Orsucci et al 2005, Dale et al 2011) on the decision-making conversations between the participants. We report strong correlations between various indexes of recurrence and collective performance. We argue this method allows us to quantify the qualities...

  12. Cathode characterization system: preliminary results with (Ba,Sr,Ca) O coated cathodes

    International Nuclear Information System (INIS)

    Nono, M.C.A.; Goncalves, J.A.N.; Barroso, J.J.; Dallaqua, R.S.; Spassovsky, I.

    1993-01-01

    The performance of a cathode characterization system for studying the emission parameters of thermal electron emitters is reported. The system consists of vacuum chamber, power supplies and equipment for measuring and control. Measurements have been taken of the emission current as function of cathode temperature and anode voltage. Several (Ba, Sr) O coated cathodes were tested and the results have shown good agreement with Child's and Richardson's laws. The experimental work function is between 1.0 and 2.0 e V. All emission parameters measured are consistent with international literature data. (author)

  13. Free Cinema: o elogio do homem comum

    OpenAIRE

    Mello, Cecília Antakly de

    2008-01-01

    Este artigo investiga o movimento documentarista "Free Cinema", que integrou a onda de renovação do cinema inglês durante o período pós-Segunda Guerra Mundial. "Free Cinema" é o nome de uma mostra de filmes organizada em fevereiro de 1956 no National Film Theatre em Londres, e reiterada por outras cinco vezes até a derradeira sexta edição em março de 1959. O termo se refere também ao movimento iniciado pelos diretores Lindsay Anderson, Karel Reisz e Tony Richardson, organizadores da primeira ...

  14. Modelling of fast hydrogen permeability of alloys for membrane gas separation

    Science.gov (United States)

    Zaika, Yu. V.; Rodchenkova, N. I.

    2017-05-01

    The method of measuring the specific hydrogen permeability is used to study various alloys that are promising for gas separation installations. The nonlinear boundary value problem of hydrogen permeability complying with the specific features of the experiment and its modifications taking into account the high transfer rate is presented. Substantial difference from the quasi-equilibrium model (Richardson approximation in the assumption of the equilibrium Sieverts' law near the surface) has been discussed. The model is tested on published experimental data on Ta77Nb23 alloy.

  15. Detecting and Applying Thermal Signals in a Tidal Flats Environment

    Science.gov (United States)

    2010-05-19

    Guarini et al., 1997]. In addition, the biology can affect the heat content, as in the ventilation of mud flats by manicure crabs [Kim et al., 2009...the values of lf and cf resulting from changes in salinity are negligible. Values of ls = 8.6 W m −1 K−1 and cs = 0.8 kJ kg−1 K−1, based on the...intertidal mudflats of the forth estuary , Scotland, J. Climatol., 5, 472–485. Jackson, D. R., and M. D. Richardson (2002), Seasonal temperature gradi- ents

  16. Age relationships from U-Th-Pb isotope studies of uranium mineralization in Wernecke breccias, Yukon Territory

    International Nuclear Information System (INIS)

    Archer, A.

    1986-01-01

    Pb-U ± Th isotope analyses for 17 specimens of uraniferous breccia from the northeastern Wernecke Mountains reveal several apparent ages for mineralization. The oldest date, 1194 Ma, reflects either initial emplacement of the breccias or their modification by effects of the Rackla of Rapitan (Windermere) thick clastic wedges and iron formation. The 510 Ma date reflects mid-Cambrian mineralization roughly coincident with regional uplift (and attendant karstification) and development of thick clastic wedges. This was also an important period for Pb-Zn mineralization. Younger dates resulted from continuing remobilization, and all isotopic ages for mineralized breccia reflect movements associated with the Richardson Fault array

  17. Visualization of Instrumental Verification Information Details (VIVID) : code development, description, and usage.

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Christopher John; Bainbridge, Bruce L.; Potter, Donald L.; Blottner, Frederick G.; Black, Amalia Rebecca

    2005-03-01

    The formulation, implementation and usage of a numerical solution verification code is described. This code uses the Richardson extrapolation procedure to estimate the order of accuracy and error of a computational program solution. It evaluates multiple solutions performed in numerical grid convergence studies to verify a numerical algorithm implementation. Analyses are performed on both structured and unstructured grid codes. Finite volume and finite element discretization programs are examined. Two and three-dimensional solutions are evaluated. Steady state and transient solution analysis capabilities are present in the verification code. Multiple input data bases are accepted. Benchmark options are included to allow for minimal solution validation capability as well as verification.

  18. Multiparameter extrapolation and deflation methods for solving equation systems

    Directory of Open Access Journals (Sweden)

    A. J. Hughes Hallett

    1984-01-01

    Full Text Available Most models in economics and the applied sciences are solved by first order iterative techniques, usually those based on the Gauss-Seidel algorithm. This paper examines the convergence of multiparameter extrapolations (accelerations of first order iterations, as an improved approximation to the Newton method for solving arbitrary nonlinear equation systems. It generalises my earlier results on single parameter extrapolations. Richardson's generalised method and the deflation method for detecting successive solutions in nonlinear equation systems are also presented as multiparameter extrapolations of first order iterations. New convergence results are obtained for those methods.

  19. Physiological responses to hypoxia and anoxia in Balanus amphitrite (Cirripedia: Thoracica)

    Digital Repository Service at National Institute of Oceanography (India)

    Desai, D.V.; Prakash, S.

    : 309-310 Pryor WA, Godber SS (1991) Oxidative stress status: an introduction. Free Radic Biol Med 10:173 Richardson TD, Brown KM (1990) Wave exposure and prey size selection in an intertidal predator. J Exp Mar Biol Ecol 142: 105-120 Southward...(2): 117-121 Demple B (1999) Radical ideas: genetic responses to oxidative stress. Clin Exp Pharmacol Physio 26: 64-68 18 Desai DV, Anil AC (2004) The impact of food type, temperature and starvation on the larval development of Balanus amphitrite...

  20. A low-cost vector processor boosting compute-intensive image processing operations

    Science.gov (United States)

    Adorf, Hans-Martin

    1992-01-01

    Low-cost vector processing (VP) is within reach of everyone seriously engaged in scientific computing. The advent of affordable add-on VP-boards for standard workstations complemented by mathematical/statistical libraries is beginning to impact compute-intensive tasks such as image processing. A case in point in the restoration of distorted images from the Hubble Space Telescope. A low-cost implementation is presented of the standard Tarasko-Richardson-Lucy restoration algorithm on an Intel i860-based VP-board which is seamlessly interfaced to a commercial, interactive image processing system. First experience is reported (including some benchmarks for standalone FFT's) and some conclusions are drawn.

  1. Creative nonfiction: narrative and revelation.

    Science.gov (United States)

    Hart, Curtis W

    2009-06-01

    Creative nonfiction and the illness narrative are recently identified approaches to literary expression. They are particularly well suited to the genre of memoir where psychological issues such as mourning and attachment and loss may be explored. The recent memoirs of Sue Erikson Bloland and Honor Moore fulfill the description of creative nonfiction. They offer their readers an opportunity to explore with them the theological and existential issues of revelation, reconciliation, and forgiveness. This paper was first presented for the Working Group on Psychoanalysis and the Arts of the Richardson Research Seminar in the History of Psychiatry at Weill Cornell Medical College.

  2. Participants of the 5th Solvay Congress

    CERN Multimedia

    Benjamin Croupie, Bruxelles

    1927-01-01

    1st line. l.to r. : I Langmeir, M Planck, M Curie, H A Lorentz, A Einstein, P Langevin, Ch E Guye, C T R Wilson, O W Richardson 2nd line l.to r. : P Debye, M Knudesen, W L Bragg, H A Kramers, P A M Dirac, A H Compton, L V De Broglie, M Born, N Bohr3rd line, l. to r. : A Piccard, E Henriot, P ehrenfest, E Herzen, Th De Donder, E Schroendinger, E Verschaffelt, W Pauli, w Heisenberg, R H Fowler

  3. Quark mean field theory and consistency with nuclear matter

    International Nuclear Information System (INIS)

    Dey, J.; Dey, M.; Frederico, T.; Tomio, L.

    1990-09-01

    1/N c expansion in QCD (with N c the number of colours) suggests using a potential from meson sector (e.g. Richardson) for baryons. For light quarks a σ field has to be introduced to ensure chiral symmetry breaking ( χ SB). It is found that nuclear matter properties can be used to pin down the χ SB-modelling. All masses, M N , m σ , m ω are found to scale with density. The equations are solved self consistently. (author). 29 refs, 2 tabs

  4. The mechanism of explosive emission excitation in thermionic energy conversion processes

    Science.gov (United States)

    Bulyga, A. V.

    A study has been made of the mechanism of explosive electron emission in vacuum thermionic converters induced by thermionic currents in the case of the anomalous Richardson effect. The latter is associated with a spotted emitting surface and temperature fluctuations. In order to account for one of the components of the electrode potential difference, it is proposed that allowance be made for the difference between the polarization signal velocity in a dense metal electron gas and that in the electron-ion gas of the electrode gap. Ways to achieve explosive emission in real thermionic converters are discussed.

  5. Mechanism of explosive emission excitation in thermionic energy conversion processes

    Energy Technology Data Exchange (ETDEWEB)

    Bulyga, A.V.

    1983-01-01

    A study has been made of the mechanism of explosive electron emission in vacuum thermionic converters induced by thermionic currents in the case of the anomalous Richardson effect. The latter is associated with a spotted emitting surface and temperature fluctuations. In order to account for one of the components of the electrode potential difference, it is proposed that allowance be made for the difference between the polarization signal velocity in a dense metal electron gas and that in the electron-ion gas of the electrode gap. Ways to achieve explosive emission in real thermionic converters are discussed.

  6. Film, Neuroaesthetics, and Empathy

    DEFF Research Database (Denmark)

    Grodal, Torben Kragh; Kramer, Mette

    2014-01-01

    The article analyzes the link between film viewing and human 'ultra-sociality' (Boyd and Richardson 1998), describing how empathy is supported by mirror resonances but also modified by appraisal mechanisms and how emotions are communicated, It further discusses how 'attainment' to film builds...... on mother-child communication and also how film genres of attachment use such attainment, especially by means of close-ups of human faces and shot-reverse shots. Finally it deals with how films boost development of cognitive and emotional intelligence...

  7. Genital piercings: what is known and what people with genital piercings tell us.

    Science.gov (United States)

    Armstrong, Myrna L; Caliendo, Carol; Roberts, Alden E

    2006-06-01

    General and subjective information about those who chose to obtain genital piercings was presented. Particularly, the assumptions made from the literature are refuted by objective and subjective data collected from intimately pierced individuals themselves. Professional nurses must not base practice decisions on assumptions but on the "best evidence with clinical experience, research, (as well as) associated patient values" (Sackett, Strauss, Richardson, Rosenberg, & Haynes, 2001, p. 10). Thus, providing clinically competent care is driven by the latest knowledge and evidence from research and patient sources. Data found here provide further empirical evidence that may help to improve client outcomes by advancing evidence-based nursing practice in relation to people with genital piercings.

  8. Inertial-Range Reconnection in Magnetohydrodynamic Turbulence and in the Solar Wind.

    Science.gov (United States)

    Lalescu, Cristian C; Shi, Yi-Kang; Eyink, Gregory L; Drivas, Theodore D; Vishniac, Ethan T; Lazarian, Alexander

    2015-07-10

    In situ spacecraft data on the solar wind show events identified as magnetic reconnection with wide outflows and extended "X lines," 10(3)-10(4) times ion scales. To understand the role of turbulence at these scales, we make a case study of an inertial-range reconnection event in a magnetohydrodynamic simulation. We observe stochastic wandering of field lines in space, breakdown of standard magnetic flux freezing due to Richardson dispersion, and a broadened reconnection zone containing many current sheets. The coarse-grain magnetic geometry is like large-scale reconnection in the solar wind, however, with a hyperbolic flux tube or apparent X line extending over integral length scales.

  9. Theoretical and experimental studies of thermal stratification in hot and cold pools of PFBR

    International Nuclear Information System (INIS)

    Velusamy, K.; Titus, G.; Rajakumar, A.; Ravichandran, G.; Padmakumar, G.; Vaidyanathan, G.; Kale, R.D.; Chetal, S.C.; Bhoje, S.B.

    1994-01-01

    Results of experimental studies carried out in two water models of size 1/24 and 1/15, to assess the free level fluctuation in the hot pool of PFBR are presented. The results when extrapolated to the prototype gives a ripple height of 50 mm. The results of thermal stratification studies carried out in 1/24 scale model, using hot and cold water indicates that the interface velocity can be correlated with the Richardson number. The paper also gives the details of computer codes developed for the estimation of flow and temperature fields in the pools. (author)

  10. Modeling Atmospheric Turbulence via Rapid Distortion Theory: Spectral Tensor of Velocity and Buoyancy

    DEFF Research Database (Denmark)

    Chougule, Abhijit S.; Mann, Jakob; Kelly, Mark C.

    2017-01-01

    A spectral tensor model is presented for turbulent fluctuations of wind velocity components and temperature, assuming uniform vertical gradients in mean temperature and mean wind speed. The model is built upon rapid distortion theory (RDT) following studies by Mann and by Hanazaki and Hunt, using...... the eddy lifetime parameterization of Mann to make the model stationary. The buoyant spectral tensor model is driven via five parameters: the viscous dissipation rate epsilon, length scale of energy-containing eddies L, a turbulence anisotropy parameter Gamma, gradient Richardson number (Ri) representing...

  11. Aitken extrapolation and epsilon algorithm for an accelerated solution of weakly singular nonlinear Volterra integral equations

    International Nuclear Information System (INIS)

    Mesgarani, H; Parmour, P; Aghazadeh, N

    2010-01-01

    In this paper, we apply Aitken extrapolation and epsilon algorithm as acceleration technique for the solution of a weakly singular nonlinear Volterra integral equation of the second kind. In this paper, based on Tao and Yong (2006 J. Math. Anal. Appl. 324 225-37.) the integral equation is solved by Navot's quadrature formula. Also, Tao and Yong (2006) for the first time applied Richardson extrapolation to accelerating convergence for the weakly singular nonlinear Volterra integral equations of the second kind. To our knowledge, this paper may be the first attempt to apply Aitken extrapolation and epsilon algorithm for the weakly singular nonlinear Volterra integral equations of the second kind.

  12. Subjektiivselt disainist / Ele Praks

    Index Scriptorium Estoniae

    Praks, Ele

    2007-01-01

    Kuni 8. IV Eesti Tarbekunsti- ja Disainimuuseumis koostöös Briti Nõukoguga avatud näitusest " Minu maailm : uus subjektiivsus kaasaegses disainis", mis koosneb rändnäitusest ja eesti disainerite satelliitnäitusest. Kuraatorid Emily Campell, Andree Cook ja Kai Lobjakas. Annike Laigo, Kärt Ojavee, Krista Leesi, Ülle Jehe, Committee' (Clare Page, Harry Richardson), Danny Browni, Doshi Levieni, Peter Traagi, Wokmedia (Michael Cross, Julie Mathias), Neutrali (Christian Grou, Tapio Snellman) ja Alison Willoughby töödest

  13. Determination of point spread function for a flat-panel X-ray imager and its application in image restoration

    International Nuclear Information System (INIS)

    Jeon, Sungchae; Cho, Gyuseong; Huh, Young; Jin, Seungoh; Park, Jongduk

    2006-01-01

    We investigate the image blur estimation methods, namely modified the Richardson-Lucy (R-L) estimator and the Wiener estimator. Based on the empirical model of the PSF, an image restoration is applied to radiological images. The accuracy of the PSF estimation under the Poisson noise and readout electronic noise is significantly better for the R-L estimator than the Wiener estimator. In the image restoration using the 2-D PSF from the R-L estimator, the result shows a good improvement in the low and middle range of spatial frequency

  14. Entrance Effects in Solar Hot Water Stores

    DEFF Research Database (Denmark)

    Shah, Louise Jivan; Furbo, Simon

    2003-01-01

    A theoretical and experimental analysis of water jets entering a solar storage tank is performed. CFD calculations of three inlet designs with different inlet flow rates were carried out to illustrate the varying behaviour of the thermal conditions in a solar store. The results showed the impact ...... in an analysis using the first and second law of thermodynamics. The results showed how the entropy changes and the exergy changes in the storage during the draw-offs influenced by the Richardson number, the volume draw-off and the initial tank conditions....

  15. The Titius-Bode law of planetary distances its history and theory

    CERN Document Server

    Nieto, Michael Martin

    1972-01-01

    The Titius-Bode Law of Planetary Distances: Its History and Theory is a 15-chapter book that first discusses the prehistory of the Law from Kepler to Kant. The next chapter details the formulation of the Titius-Bode Law. Subsequent chapters describe the Law's early successes and failures, early modifications of the Law, the Blagg-Richardson formulation, and the significance of the Law with respect to the origin of the solar system. Other chapters discuss the theories of all types that have been proposed to explain the """"classical Titius-Bode Law"""", i.e. the geometric progression.

  16. Pseudoinverse preconditioners and iterative methods for large dense linear least-squares problems

    Directory of Open Access Journals (Sweden)

    Oskar Cahueñas

    2013-05-01

    Full Text Available We address the issue of approximating the pseudoinverse of the coefficient matrix for dynamically building preconditioning strategies for the numerical solution of large dense linear least-squares problems. The new preconditioning strategies are embedded into simple and well-known iterative schemes that avoid the use of the, usually ill-conditioned, normal equations. We analyze a scheme to approximate the pseudoinverse, based on Schulz iterative method, and also different iterative schemes, based on extensions of Richardson's method, and the conjugate gradient method, that are suitable for preconditioning strategies. We present preliminary numerical results to illustrate the advantages of the proposed schemes.

  17. Contact Between Birth and Adoptive Families During the First Year Post-Placement: Perspectives of Lesbian, Gay, and Heterosexual Parents.

    Science.gov (United States)

    Farr, Rachel H; Goldberg, Abbie E

    Despite growing visibility of lesbian- and gay-parent adoption, only one qualitative study has examined birth family contact among adoptive families with lesbian and gay parents (Goldberg, Kinkler, Richardson, & Downing, 2011). We studied adoptive parents' (34 lesbian, 32 gay, and 37 heterosexual; N = 103 families) perspectives of birth family contact across the first year post-placement. Using questionnaire and interview data, we found few differences in openness dynamics by parental sexual orientation. Most reported some birth mother contact, most had legally finalized their adoption, and few described plans to withhold information from children. We discuss implications for clinical practice, policy, and research.

  18. Transport synthetic acceleration with opposing reflecting boundary conditions

    Energy Technology Data Exchange (ETDEWEB)

    Zika, M R; Adams, M L

    2000-02-01

    The transport synthetic acceleration (TSA) scheme is extended to problems with opposing reflecting boundary conditions. This synthetic method employs a simplified transport operator as its low-order approximation. A procedure is developed that allows the use of the conjugate gradient (CG) method to solve the resulting low-order system of equations. Several well-known transport iteration algorithms are cast in a linear algebraic form to show their equivalence to standard iterative techniques. Source iteration in the presence of opposing reflecting boundary conditions is shown to be equivalent to a (poorly) preconditioned stationary Richardson iteration, with the preconditioner defined by the method of iterating on the incident fluxes on the reflecting boundaries. The TSA method (and any synthetic method) amounts to a further preconditioning of the Richardson iteration. The presence of opposing reflecting boundary conditions requires special consideration when developing a procedure to realize the CG method for the proposed system of equations. The CG iteration may be applied only to symmetric positive definite matrices; this condition requires the algebraic elimination of the boundary angular corrections from the low-order equations. As a consequence of this elimination, evaluating the action of the resulting matrix on an arbitrary vector involves two transport sweeps and a transmission iteration. Results of applying the acceleration scheme to a simple test problem are presented.

  19. Effects of 5.4 MeV alpha-particle irradiation on the electrical properties of nickel Schottky diodes on 4H–SiC

    Energy Technology Data Exchange (ETDEWEB)

    Omotoso, E. [Department of Physics, University of Pretoria, Private Bag X20, Hatfield 0028 (South Africa); Department of Physics, Obafemi Awolowo University, Ile-Ife 220005 (Nigeria); Meyer, W.E.; Auret, F.D.; Paradzah, A.T.; Diale, M.; Coelho, S.M.M.; Janse van Rensburg, P.J.; Ngoepe, P.N.M. [Department of Physics, University of Pretoria, Private Bag X20, Hatfield 0028 (South Africa)

    2015-12-15

    Current–voltage, capacitance–voltage and conventional deep level transient spectroscopy at temperature ranges from 40 to 300 K have been employed to study the influence of alpha-particle irradiation from an {sup 241}Am source on Ni/4H–SiC Schottky contacts. The nickel Schottky barrier diodes were resistively evaporated on n-type 4H–SiC samples of doping density of 7.1 × 10{sup 15} cm{sup −3}. It was observed that radiation damage caused an increase in ideality factors of the samples from 1.04 to 1.07, an increase in Schottky barrier height from 1.25 to 1.31 eV, an increase in series resistance from 48 to 270 Ω but a decrease in saturation current density from 55 to 9 × 10{sup −12} A m{sup −2} from I–V plots at 300 K. The free carrier concentration of the sample decreased slightly after irradiation. Conventional DLTS showed peaks due to four deep levels for as-grown and five deep levels after irradiation. The Richardson constant, as determined from a modified Richardson plot assuming a Gaussian distribution of barrier heights for the as-grown and irradiated samples were 133 and 151 A cm{sup −2} K{sup −2}, respectively. These values are similar to literature values.

  20. Rate constants of chemical reactions from semiclassical transition state theory in full and one dimension

    Energy Technology Data Exchange (ETDEWEB)

    Greene, Samuel M., E-mail: samuel.greene@chem.ox.ac.uk; Shan, Xiao, E-mail: xiao.shan@chem.ox.ac.uk; Clary, David C., E-mail: david.clary@chem.ox.ac.u [Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ (United Kingdom)

    2016-06-28

    Semiclassical Transition State Theory (SCTST), a method for calculating rate constants of chemical reactions, offers gains in computational efficiency relative to more accurate quantum scattering methods. In full-dimensional (FD) SCTST, reaction probabilities are calculated from third and fourth potential derivatives along all vibrational degrees of freedom. However, the computational cost of FD SCTST scales unfavorably with system size, which prohibits its application to larger systems. In this study, the accuracy and efficiency of 1-D SCTST, in which only third and fourth derivatives along the reaction mode are used, are investigated in comparison to those of FD SCTST. Potential derivatives are obtained from numerical ab initio Hessian matrix calculations at the MP2/cc-pVTZ level of theory, and Richardson extrapolation is applied to improve the accuracy of these derivatives. Reaction barriers are calculated at the CCSD(T)/cc-pVTZ level. Results from FD SCTST agree with results from previous theoretical and experimental studies when Richardson extrapolation is applied. Results from our implementation of 1-D SCTST, which uses only 4 single-point MP2/cc-pVTZ energy calculations in addition to those for conventional TST, agree with FD results to within a factor of 5 at 250 K. This degree of agreement and the efficiency of the 1-D method suggest its potential as a means of approximating rate constants for systems too large for existing quantum scattering methods.

  1. [Breast cancer: histological prognosis from biopsy material].

    Science.gov (United States)

    Veith, F; Picco, C

    1977-01-01

    Two histological factors to be taken into consideration for prognosis in pretreatment schedules of breast cancer have been studied on a group of 352 cases treated by non-mutilating therapeutics at the Fondation Curie between 1960 and 1970. The tumour material the slides of which we have reexamined "blindly", i.e. ignoring the evolution of the case had been obtained mostly by drill-biopsy. Histological groups and types have been determined following an analytical classification for computer purpose. The degree of malignancy was calculated with the method of Scarff-Bloom-Richardson. The analyzed data have been memorized on computer and then confronted with the elements of the T.N.M. classification and the survival of the patients involved. It appeared that if drill-biopsie have been performed correctly the histological type may be defined in eighty percent of cases. And it is likewise possible to calculate the histological grade of malignancy for each mammary cancer. With such a material the value for prognosis by means of the Scarff-Bloom-Richardson method still remains if applied only to adenocarcinoma of the "common infiltrating type".

  2. Behaviour of the Sedimentation in a System of Microparticles

    Directory of Open Access Journals (Sweden)

    Salinas-Salas G.

    2012-04-01

    Full Text Available This paper presents the experimental determination of the behaviour of the sedimentation velocity of systems of micro particles based on the results achieved, evaluating whether there is any difference between the value of the exponent of hindrance function, determined by Richardson and Zaki (1954, in the case of noncolloidal micro particles in order of size between 1,500 nm to 200 nm, as well as describing the behaviour of the already mentioned exponent. At the same time, exposed the experimental work developed under the standard DIN 66111 (1989, using an analytical centrifuge, as well as the analysis of data extracted from it. The data showed that there is a difference between the value proposed by Richardson and Zaki in 1954, in relation to those experimentally determined. This allows us to infer that for micro-systems smaller than 1,000 nm, there is a new value of the exponent of the hindrance function, approximately of the order of 11.5. Additionally, it was determined that there is a relation between the already mentioned exponent and the average size of micro particles that comprise the system of particles settled.

  3. Schottky diode model for non-parabolic dispersion in narrow-gap semiconductor and few-layer graphene

    Science.gov (United States)

    Ang, Yee Sin; Ang, L. K.; Zubair, M.

    Despite the fact that the energy dispersions are highly non-parabolic in many Schottky interfaces made up of 2D material, experimental results are often interpreted using the conventional Schottky diode equation which, contradictorily, assumes a parabolic energy dispersion. In this work, the Schottky diode equation is derived for narrow-gap semiconductor and few-layer graphene where the energy dispersions are highly non-parabolic. Based on Kane's non-parabolic band model, we obtained a more general Kane-Schottky scaling relation of J (T2 + γkBT3) which connects the contrasting J T2 in the conventional Schottky interface and the J T3 scaling in graphene-based Schottky interface via a non-parabolicity parameter, γ. For N-layer graphene of ABC -stacking and of ABA -stacking, the scaling relation follows J T 2 / N + 1 and J T3 respectively. Intriguingly, the Richardson constant extracted from the experimental data using an incorrect scaling can differ with the actual value by more than two orders of magnitude. Our results highlights the importance of using the correct scaling relation in order to accurately extract important physical properties, such as the Richardson constant and the Schottky barrier's height.

  4. Translation and validation of the Malay version of the Stroke Knowledge Test.

    Science.gov (United States)

    Sowtali, Siti Noorkhairina; Yusoff, Dariah Mohd; Harith, Sakinah; Mohamed, Monniaty

    2016-04-01

    To date, there is a lack of published studies on assessment tools to evaluate the effectiveness of stroke education programs. This study developed and validated the Malay language version of the Stroke Knowledge Test research instrument. This study involved translation, validity, and reliability phases. The instrument underwent backward and forward translation of the English version into the Malay language. Nine experts reviewed the content for consistency, clarity, difficulty, and suitability for inclusion. Perceived usefulness and utilization were obtained from experts' opinions. Later, face validity assessment was conducted with 10 stroke patients to determine appropriateness of sentences and grammar used. A pilot study was conducted with 41 stroke patients to determine the item analysis and reliability of the translated instrument using the Kuder Richardson 20 or Cronbach's alpha. The final Malay version Stroke Knowledge Test included 20 items with good content coverage, acceptable item properties, and positive expert review ratings. Psychometric investigations suggest that Malay version Stroke Knowledge Test had moderate reliability with Kuder Richardson 20 or Cronbach's alpha of 0.58. Improvement is required for Stroke Knowledge Test items with unacceptable difficulty indices. Overall, the average rating of perceived usefulness and perceived utility of the instruments were both 72.7%, suggesting that reviewers were likely to use the instruments in their facilities. Malay version Stroke Knowledge Test was a valid and reliable tool to assess educational needs and to evaluate stroke knowledge among participants of group-based stroke education programs in Malaysia.

  5. Determination of Solution Accuracy of Numerical Schemes as Part of Code and Calculation Verification

    Energy Technology Data Exchange (ETDEWEB)

    Blottner, F.G.; Lopez, A.R.

    1998-10-01

    This investigation is concerned with the accuracy of numerical schemes for solving partial differential equations used in science and engineering simulation codes. Richardson extrapolation methods for steady and unsteady problems with structured meshes are presented as part of the verification procedure to determine code and calculation accuracy. The local truncation error de- termination of a numerical difference scheme is shown to be a significant component of the veri- fication procedure as it determines the consistency of the numerical scheme, the order of the numerical scheme, and the restrictions on the mesh variation with a non-uniform mesh. Genera- tion of a series of co-located, refined meshes with the appropriate variation of mesh cell size is in- vestigated and is another important component of the verification procedure. The importance of mesh refinement studies is shown to be more significant than just a procedure to determine solu- tion accuracy. It is suggested that mesh refinement techniques can be developed to determine con- sistency of numerical schemes and to determine if governing equations are well posed. The present investigation provides further insight into the conditions and procedures required to effec- tively use Richardson extrapolation with mesh refinement studies to achieve confidence that sim- ulation codes are producing accurate numerical solutions.

  6. Characteristics of laminar MHD fluid hammer in pipe

    International Nuclear Information System (INIS)

    Huang, Z.Y.; Liu, Y.J.

    2016-01-01

    As gradually wide applications of MHD fluid, transportation as well as control with pumps and valves is unavoidable, which induces MHD fluid hammer. The paper attempts to combine MHD effect and fluid hammer effect and to investigate the characteristics of laminar MHD fluid hammer. A non-dimensional fluid hammer model, based on Navier–Stocks equations, coupling with Lorentz force is numerically solved in a reservoir–pipe–valve system with uniform external magnetic field. The MHD effect is represented by the interaction number which associates with the conductivity of the MHD fluid as well as the external magnetic field and can be interpreted as the ratio of Lorentz force to Joukowsky force. The transient numerical results of pressure head, average velocity, wall shear stress, velocity profiles and shear stress profiles are provided. The additional MHD effect hinders fluid motion, weakens wave front and homogenizes velocity profiles, contributing to obvious attenuation of oscillation, strengthened line packing and weakened Richardson annular effect. Studying the characteristics of MHD laminar fluid hammer theoretically supplements the gap of knowledge of rapid-transient MHD flow and technically provides beneficial information for MHD pipeline system designers to better devise MHD systems. - Highlights: • Characteristics of laminar MHD fluid hammer are discussed by simulation. • MHD effect has significant influence on attenuation of wave. • MHD effect strengthens line packing. • MHD effect inhibits Richardson annular effect.

  7. Atmospheric stability analysis over statically and dynamically rough surfaces

    Science.gov (United States)

    Maric, Emina; Metzger, Meredith; Singha, Arindam; Sadr, Reza

    2011-11-01

    The ratio of buoyancy flux to turbulent kinetic energy production in the atmospheric surface layer is investigated experimentally for air flow over two types of surfaces characterized by static and dynamic roughness. In this study, ``static'' refers to the time-invariant nature of naturally-occurring roughness over a mud/salt playa; while, ``dynamic'' refers to the behavior of water waves along an air-water interface. In both cases, time-resolved measurements of the momentum and heat fluxes were acquired from synchronized 3D sonic anemometers mounted on a vertical tower. Field campaigns were conducted at two sites, representing the ``statically'' and ``dynamically'' rough surfaces, respectively: (1) the SLTEST facility in Utah's western desert, and (2) the new Doha airport in Qatar under construction along the coast of the Persian Gulf. Note, at site 2, anemometers were located directly above the water by extension from a tower secured to the end of a 1 km-long pier. Comparisons of the Monin-Obukhov length, flux Richardson number, and gradient Richardson number are presented, and discussed in the context of the observed evolution of the turbulent spectra in response to diurnal variations of atmospheric stability. Supported by the Qatar National Research Fund.

  8. Experimental study of laminar mixed convection in a rod bundle with mixing vane spacer grids

    Energy Technology Data Exchange (ETDEWEB)

    Mohanta, Lokanath, E-mail: lxm971@psu.edu [Department of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park, PA 16802 (United States); Cheung, Fan-Bill [Department of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park, PA 16802 (United States); Bajorek, Stephen M.; Tien, Kirk; Hoxie, Chris L. [Office of Nuclear Regulatory Research, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001 (United States)

    2017-02-15

    Highlights: • Investigated the heat transfer during mixed laminar convection in a rod bundle with linearly varying heat flux. • The Nusselt number increases downstream of the inlet with increasing Richardson number. • Developed an enhancement factor to account for the effects of mixed convection over the forced laminar heat transfer. - Abstract: Heat transfer by mixed convection in a rod bundle occurs when convection is affected by both the buoyancy and inertial forces. Mixed convection can be assumed when the Richardson number (Ri = Gr/Re{sup 2}) is on the order of unity, indicating that both forced and natural convection are important contributors to heat transfer. In the present study, data obtained from the Rod Bundle Heat Transfer (RBHT) facility was used to determine the heat transfer coefficient in the mixed convection regime, which was found to be significantly larger than those expected assuming purely forced convection based on the inlet flow rate. The inlet Reynolds (Re) number for the tests ranged from 500 to 1300, while the Grashof (Gr) number varied from 1.5 × 10{sup 5} to 3.8 × 10{sup 6} yielding 0.25 < Ri < 4.3. Using results from RBHT test along with the correlation from the FLECHT-SEASET test program for laminar forced convection, a new correlation ​is proposed for mixed convection in a rod bundle. The new correlation accounts for the enhancement of heat transfer relative to laminar forced convection.

  9. Stability-class determination: a comparison for one site

    International Nuclear Information System (INIS)

    Bowen, B.M.; Dewart, J.M.; Chen, A.I.

    1983-01-01

    The Pasquill method of determining stability class at a site with irregular terrain with other commonly used methods: vertical temperature difference (#betta#T); Richardson number (Ri) and Bulk Richardson number (Ri/sub B/); and horizontal standard deviation of wind and vertical standard deviation of wind. Also, the indirect methods of measuring turbulence, such as the Pasquill method, are compared to direct measures of turbulence. The various methods for determining stability class are analyzed and compared with the Pasquill classification scheme at 2 sites with irregular terrain. The Pasquill categories were estimated objectively and compared with other stability indicators for 15-minute periods over a year. The results show that near-surface #betta#T distinguishes the neutral category very well. However, it does not differentiate the specific stable and unstable categories very well. Both the Ri and Ri/sub B/, indicators of both thermal and mechanical turbulence, correlate very well with and distinguish the different stability categories. Due to the irregular terrain, the various methods of determining stability may be even better indicators of turbulence and diffusion if the wind direction were taken into account. It is suggested that further study investigate the methods by wind direction

  10. Analysis of Schottky Barrier Parameters and Current Transport Properties of V/p-Type GaN Schottky Junction at Low Temperatures

    Science.gov (United States)

    Asha, B.; Harsha, Cirandur Sri; Padma, R.; Rajagopal Reddy, V.

    2018-05-01

    The electrical characteristics of a V/p-GaN Schottky junction have been investigated by current-voltage (I-V) and capacitance-voltage (C-V) characteristics under the assumption of the thermionic emission (TE) theory in the temperature range of 120-280 K with steps of 40 K. The zero-bias barrier height (ΦB0), ideality factor (n), flat-band barrier height (ΦBF) and series resistance (R S) values were evaluated and were found to be strongly temperature dependent. The results revealed that the ΦB0 values increase, whereas n, ΦFB and R S values decrease, with increasing temperature. Using the conventional Richardson plot, the mean barrier height (0.39 eV) and Richardson constant (8.10 × 10-10 Acm-2 K-2) were attained. The barrier height inhomogeneities were demonstrated by assuming a Gaussian distribution function. The interface state density (N SS) values were found to decrease with increasing temperature. The reverse leakage current mechanism of the V/p-GaN Schottky junction was found to be governed by Poole-Frenkel emission at all temperatures.

  11. Buoyancy effects laminar slot jet impinging on a surface with constant heat flux

    International Nuclear Information System (INIS)

    Shokouhmand, H.; Esfahanian, V.; Masoodi, R.

    2004-01-01

    The two-dimensional laminar air jet issuing from a nozzle of half which terminates at height above a flat plate normal to the jet is numerically on the flow and thermal structure of the region near impingement. The impinging surface is maintained at a constant heat flux condition. The full Navier-Stocks and energy equations are solved by a finite difference method to evaluate the velocity profiles and temperature distribution. The governing parameters and their ranges are: Reynolds number Re, 10-50, Grashof number Gr, 0-50, Richardson number Ri=Gr/ Re 2 , Non dimensional nozzle height H,2-3. Results of the free streamline, local friction factor and heat transfer coefficient are graphically presented. It is found that enhancement of the heat transfer rate is substantial for high Richardson number conditions. Although the laminar jet impingement for isothermal condition has been already studied, however the constant heat flux has not been studied enough. the present paper will analyze a low velocity air jet, Which can be used for cooling of a simulated electronics package

  12. Radiative instabilities of atmospheric jets and boundary layers

    International Nuclear Information System (INIS)

    Candelier, J.

    2010-01-01

    Complex flows occur in the atmosphere and they can be source of internal gravity waves. We focus here on the sources associated with radiative and shear (or Kelvin-Helmholtz) instabilities. Stability studies of shear layers in a stably stratified fluid concern mainly cases where shear and stratification are aligned along the same direction. In these cases, Miles (1961) and Howard (1961) found a necessary condition for stability based on the Richardson number: Ri ≥ 1/4. In this thesis, we show that this condition is not necessary when shear and stratification are not aligned: we demonstrate that a two-dimensional planar Bickley jet can be unstable for all Richardson numbers. Although the most unstable mode remains 2D, we show there exists an infinite family of 3D unstable modes exhibiting a radiative structure. A WKBJ theory is found to provide the main characteristics of these modes. We also study an inviscid and stratified boundary layer over an inclined wall with non-Boussinesq and compressible effects. We show that this flow is unstable as soon as the wall is not horizontal for all Froude numbers and that strongly stratified 3D perturbations behave exactly like compressible 2D perturbations. Applications of the results to the jet stream and the atmospheric boundary layer are proposed. (author) [fr

  13. Analysis of temperature-dependant current–voltage characteristics and extraction of series resistance in Pd/ZnO Schottky barrier diodes

    Energy Technology Data Exchange (ETDEWEB)

    Mayimele, M A, E-mail: meehleketo@gmail.com; Rensburg, J P van. Janse; Auret, F D; Diale, M

    2016-01-01

    We report on the analysis of current voltage (I–V) measurements performed on Pd/ZnO Schottky barrier diodes (SBDs) in the 80–320 K temperature range. Assuming thermionic emission (TE) theory, the forward bias I–V characteristics were analysed to extract Pd/ZnO Schottky diode parameters. Comparing Cheung’s method in the extraction of the series resistance with Ohm’s law, it was observed that at lower temperatures (T<180 K) the series resistance decreased with increasing temperature, the absolute minimum was reached near 180 K and increases linearly with temperature at high temperatures (T>200 K). The barrier height and the ideality factor decreased and increased, respectively, with decrease in temperature, attributed to the existence of barrier height inhomogeneity. Such inhomogeneity was explained based on TE with the assumption of Gaussian distribution of barrier heights with a mean barrier height of 0.99 eV and a standard deviation of 0.02 eV. A mean barrier height of 0.11 eV and Richardson constant value of 37 A cm{sup −2} K{sup −2} were determined from the modified Richardson plot that considers the Gaussian distribution of barrier heights.

  14. Validación de un cuestionario para evaluar causas administrativas de la baja notificación de reacciones adversas a los medicamentos

    Directory of Open Access Journals (Sweden)

    Lisset Ortiz Zamora

    Full Text Available RESUMEN Objetivo Diseñar y validar una encuesta para conocer las causas de tipo administrativo que pueden influir en la baja notificación de reacciones adversas a medicamentos (RAM. Métodos El cuestionario se diseñó a partir de una revisión bibliográfica y una tormenta de ideas. Las variables que se consideraron que pueden influir en la notificación fueron la carga de trabajo de los profesionales y su percepción del control de la actividad de farmacovigilancia. Para su validación, se encuestó a 60 profesionales de una muestra de conveniencia. La confiabilidad se calculó con la alfa de Cronbach y el coeficiente de Kuder Richardson. La validez de contenido se cuantificó con el coeficiente de Kendall y la de criterio, mediante la concordancia con el criterio establecido. Resultados El cuestionario tipo encuesta quedó constituido por 15 preguntas y estructurado en dos partes, información general y causas administrativas de la baja notificación de RAM. La alfa de Cronbach fue 0,87, el coeficiente de Kuder Richardson, 0,9033, y la validez total, 1,51, resultante de 70% de concordancia y un coeficiente de correlación por rangos de 0,81. Conclusiones La confiabilidad de la encuesta validada fue aceptable-elevada y su validez, aceptable.

  15. Point spread functions and deconvolution of ultrasonic images.

    Science.gov (United States)

    Dalitz, Christoph; Pohle-Fröhlich, Regina; Michalk, Thorsten

    2015-03-01

    This article investigates the restoration of ultrasonic pulse-echo C-scan images by means of deconvolution with a point spread function (PSF). The deconvolution concept from linear system theory (LST) is linked to the wave equation formulation of the imaging process, and an analytic formula for the PSF of planar transducers is derived. For this analytic expression, different numerical and analytic approximation schemes for evaluating the PSF are presented. By comparing simulated images with measured C-scan images, we demonstrate that the assumptions of LST in combination with our formula for the PSF are a good model for the pulse-echo imaging process. To reconstruct the object from a C-scan image, we compare different deconvolution schemes: the Wiener filter, the ForWaRD algorithm, and the Richardson-Lucy algorithm. The best results are obtained with the Richardson-Lucy algorithm with total variation regularization. For distances greater or equal twice the near field distance, our experiments show that the numerically computed PSF can be replaced with a simple closed analytic term based on a far field approximation.

  16. DC conduction mechanism and dielectric properties of Poly (methyl methacrylate)/Poly (vinyl acetate) blends doped and undoped with malachite green

    International Nuclear Information System (INIS)

    Abd-El Kader, F.H.; Osman, W.H.; Hafez, R.S.

    2013-01-01

    Cast thin films of Poly (methyl methacrylate)/Poly (vinyl acetate) blends of different concentrations undoped and doped with malachite green have been prepared and subjected to both dc electrical conduction and dielectric spectroscopy measurements. The analysis of dc electrical conduction data showed that the space charge limited current mechanism has been dominant for Poly (vinyl acetate) while Schottky-Richardson conduction mechanism prevailed for the Poly (methyl methacrylate) and blended samples. The values of field lowering constant β and the thermal activation energy ΔE involved in the dc conduction were reported, which provide another support for the suggested Schottky-Richardson mechanism. The increase in current for the blend sample doped with malachite green has been attributed to the formation of charge transfer complexes inside the polyblend matrix. The dielectric constant as a function of temperature for all samples have been calculated which are affected by the composition ratio and the addition of dye. The relaxation peak that appeared in the dielectric loss curve at 347 K for the doped blend sample is related to local dipoles that are present in the dye material. The obtained relaxation process spectra present in the investigated samples were analyzed with the well-known model of Havriliak-Negami.

  17. Turbulent mixed buoyancy driven flow and heat transfer in lid driven enclosure

    International Nuclear Information System (INIS)

    Mishra, Ajay Kumar; Sharma, Anil Kumar

    2015-01-01

    Turbulent mixed buoyancy driven flow and heat transfer of air in lid driven rectangular enclosure has been investigated for Grashof number in the range of 10 8 to 10 11 and for Richardson number 0.1, 1 and 10. Steady two dimensional Reynolds-Averaged-Navier-Stokes equations and conservation equations of mass and energy, coupled with the Boussinesq approximation, are solved. The spatial derivatives in the equations are discretized using the finite-element method. The SIMPLE algorithm is used to resolve pressure-velocity coupling. Turbulence is modeled with the k-ω closure model with physical boundary conditions along with the Boussinesq approximation, for the flow and heat transfer. The predicted results are validated against benchmark solutions reported in literature. The results include stream lines and temperature fields are presented to understand flow and heat transfer characteristics. There is a marked reduction in mean Nusselt number (about 58%) as the Richardson number increases from 0.1 to 10 for the case of Ra=10 10 signifying the effect of reduction of top lid velocity resulting in reduction of turbulent mixing. (author)

  18. Experimental study of unsteady thermally stratified flow

    International Nuclear Information System (INIS)

    Lee, Sang Jun; Chung, Myung Kyoon

    1985-01-01

    Unsteady thermally stratified flow caused by two-dimensional surface discharge of warm water into a oblong channel was investigated. Experimental study was focused on the rapidly developing thermal diffusion at small Richardson number. The basic objectives were to study the interfacial mixing between a flowing layer of warm water and an underlying body of cold water and to accumulate experimental data to test computational turbulence models. Mean velocity field measurements were carried out by using NMR-CT(Nuclear Magnetic Resonance-Computerized Tomography). It detects quantitative flow image of any desired section in any direction of flow in short time. Results show that at small Richardson number warm layer rapidly penetrates into the cold layer because of strong turbulent mixing and instability between the two layers. It is found that the transfer of heat across the interface is more vigorous than that of momentum. It is also proved that the NMR-CT technique is a very valuable tool to measure unsteady three dimensional flow field. (Author)

  19. Assessing forest roads and their edge effects on burn severity patterns using satellite data and geospatial analysis

    Science.gov (United States)

    Newman, S. D.; Clague, J. J.; Rabus, B.; Stead, D.

    2011-12-01

    Multiple, active, deep-seated gravitational slope deformations (DSGSD) are present near the Trans-Alaska Pipeline and Richardson Highway in the east-central Alaska Range, Alaska, USA. We documented spatial and temporal variations in rates of surface movement of the DSGSDs between 2003 and 2011 using RADARSAT-1 and RADARSAT-2 D-InSAR images. Deformation rates exceed 10 cm/month over very large areas (>1 km2) of many rock slopes. Recent climatic change and strong seismic shaking, especially during the 2002 M 7.9 Denali Fault earthquake, appear to have exacerbated slope deformation. We also mapped DSGSD geological and morphological characteristics using field- and GIS-based methods, and constructed a conceptual 2D distinct-element numerical model of one of the DSGSDs. Preliminary results indicate that large-scale buckling or kink-band slumping may be occurring. The DSGSDs are capable of generating long-runout landslides that might impact the Trans-Alaska Pipeline and Richardson Highway. They could also block tributary valleys, thereby impounding lakes that might drain suddenly. Wrapped 24-day RADARSAT-2 descending spotlight interferogram showing deformation north of Fels Glacier. The interferogram is partially transparent and is overlaid on a 2009 WorldView-1 panchromatic image. Acquisition interval: August 2 - August 26, 2011. UTM Zone 6N.

  20. Deep-seated gravitational slope deformations near the Trans-Alaska Pipeline, east-central Alaska Range, Alaska, USA

    Science.gov (United States)

    Newman, S. D.; Clague, J. J.; Rabus, B.; Stead, D.

    2013-12-01

    Multiple, active, deep-seated gravitational slope deformations (DSGSD) are present near the Trans-Alaska Pipeline and Richardson Highway in the east-central Alaska Range, Alaska, USA. We documented spatial and temporal variations in rates of surface movement of the DSGSDs between 2003 and 2011 using RADARSAT-1 and RADARSAT-2 D-InSAR images. Deformation rates exceed 10 cm/month over very large areas (>1 km2) of many rock slopes. Recent climatic change and strong seismic shaking, especially during the 2002 M 7.9 Denali Fault earthquake, appear to have exacerbated slope deformation. We also mapped DSGSD geological and morphological characteristics using field- and GIS-based methods, and constructed a conceptual 2D distinct-element numerical model of one of the DSGSDs. Preliminary results indicate that large-scale buckling or kink-band slumping may be occurring. The DSGSDs are capable of generating long-runout landslides that might impact the Trans-Alaska Pipeline and Richardson Highway. They could also block tributary valleys, thereby impounding lakes that might drain suddenly. Wrapped 24-day RADARSAT-2 descending spotlight interferogram showing deformation north of Fels Glacier. The interferogram is partially transparent and is overlaid on a 2009 WorldView-1 panchromatic image. Acquisition interval: August 2 - August 26, 2011. UTM Zone 6N.

  1. Modulation of electrical properties in Cu/n-type InP Schottky junctions using oxygen plasma treatment

    International Nuclear Information System (INIS)

    Kim, Hogyoung; Jung, Chan Yeong; Hyun Kim, Se; Cho, Yunae; Kim, Dong-Wook

    2015-01-01

    Using current–voltage (I–V) measurements, we investigated the effect of oxygen plasma treatment on the temperature-dependent electrical properties of Cu/n-type indium phosphide (InP) Schottky contacts at temperatures in the range 100–300 K. Changes in the electrical parameters were evident below 180 K for the low-plasma-power sample (100 W), which is indicative of the presence of a wider distribution of regions of low barrier height. Modified Richardson plots were used to obtain Richardson constants, which were similar to the theoretical value of 9.4 A cm −2 K −2 for n-type InP. This suggests that, for all the samples, a thermionic emission model including a spatially inhomogeneous Schottky barrier can be used to describe the charge transport phenomena at the metal/semiconductor interface. The voltage dependence of the reverse-bias current revealed that Schottky emission was dominant for the untreated and high-plasma-power (250 W) samples. For the low-plasma-power sample, Poole–Frenkel emission was dominant at low voltages, whereas Schottky emission dominated at higher voltages. Defect states and nonuniformity of the interfacial layer appear to be significant in the reverse-bias charge transport properties of the low-plasma-power sample. (paper)

  2. Sedimentological regimes for turbidity currents: Depth-averaged theory

    Science.gov (United States)

    Halsey, Thomas C.; Kumar, Amit; Perillo, Mauricio M.

    2017-07-01

    Turbidity currents are one of the most significant means by which sediment is moved from the continents into the deep ocean; their properties are interesting both as elements of the global sediment cycle and due to their role in contributing to the formation of deep water oil and gas reservoirs. One of the simplest models of the dynamics of turbidity current flow was introduced three decades ago, and is based on depth-averaging of the fluid mechanical equations governing the turbulent gravity-driven flow of relatively dilute turbidity currents. We examine the sedimentological regimes of a simplified version of this model, focusing on the role of the Richardson number Ri [dimensionless inertia] and Rouse number Ro [dimensionless sedimentation velocity] in determining whether a current is net depositional or net erosional. We find that for large Rouse numbers, the currents are strongly net depositional due to the disappearance of local equilibria between erosion and deposition. At lower Rouse numbers, the Richardson number also plays a role in determining the degree of erosion versus deposition. The currents become more erosive at lower values of the product Ro × Ri, due to the effect of clear water entrainment. At higher values of this product, the turbulence becomes insufficient to maintain the sediment in suspension, as first pointed out by Knapp and Bagnold. We speculate on the potential for two-layer solutions in this insufficiently turbulent regime, which would comprise substantial bedload flow with an overlying turbidity current.

  3. Characterization of the inhomogeneous barrier distribution in a Pt/(100)β-Ga2O3 Schottky diode via its temperature-dependent electrical properties

    Science.gov (United States)

    Jian, Guangzhong; He, Qiming; Mu, Wenxiang; Fu, Bo; Dong, Hang; Qin, Yuan; Zhang, Ying; Xue, Huiwen; Long, Shibing; Jia, Zhitai; Lv, Hangbing; Liu, Qi; Tao, Xutang; Liu, Ming

    2018-01-01

    β-Ga2O3 is an ultra-wide bandgap semiconductor with applications in power electronic devices. Revealing the transport characteristics of β-Ga2O3 devices at various temperatures is important for improving device performance and reliability. In this study, we fabricated a Pt/β-Ga2O3 Schottky barrier diode with good performance characteristics, such as a low ON-resistance, high forward current, and a large rectification ratio. Its temperature-dependent current-voltage and capacitance-voltage characteristics were measured at various temperatures. The characteristic diode parameters were derived using thermionic emission theory. The ideality factor n was found to decrease from 2.57 to 1.16 while the zero-bias barrier height Φb0 increased from 0.47 V to 1.00 V when the temperature was increased from 125 K to 350 K. This was explained by the Gaussian distribution of barrier height inhomogeneity. The mean barrier height Φ ¯ b0 = 1.27 V and zero-bias standard deviation σ0 = 0.13 V were obtained. A modified Richardson plot gave a Richardson constant A* of 36.02 A.cm-2.K-2, which is close to the theoretical value of 41.11 A.cm-2.K-2. The differences between the barrier heights determined using the capacitance-voltage and current-voltage curves were also in line with the Gaussian distribution of barrier height inhomogeneity.

  4. Relativistic meson spectroscopy in momentum space

    International Nuclear Information System (INIS)

    Hersbach, H.

    1994-01-01

    In this paper a relativistic constituent-quark model based on the Ruijgrok--de Groot formalism is presented. The quark model is not defined in configuration space, but in momentum space. The complete meson spectrum, with the exception of the self-conjugate light unflavored mesons, is calculated. The potential used consists of a one-gluon exchange (OGE) part and a confining part. For the confining part a relativistic generalization of the linear plus constant potential was used, which is well defined in momentum space without introducing any singularities. For the OGE part several potentials were investigated. Retardations were included at all places. By the use of a fitting procedure involving 52 well-established mesons, but results were obtained for a potential consisting of a purely vector Richardson potential and a purely scalar confining potential. Reasonable results were also obtained for a modified Richardson potential. Most meson masses, with the exception of the π, the K, and the K 0 * , were found to be quite well described by the model

  5. Numerical simulation of double-diffusive mixed convective flow in rectangular enclosure with insulated moving lid

    Energy Technology Data Exchange (ETDEWEB)

    Teamah, M.A. [Faculty of Engineering, Alexandria University, Mech. Eng. Dept, Alexandria (Egypt); El-Maghlany, W.M. [Faculty of Engineering, Suez Canal University, Ismailia (Egypt)

    2010-09-15

    The present study is concerned with the mixed convection in a rectangular lid-driven cavity under the combined buoyancy effects of thermal and mass diffusion. Double-diffusive convective flow in a rectangular enclosure with moving upper surface is studied numerically. Both upper and lower surfaces are being insulated and impermeable. Constant different temperatures and concentration are imposed along the vertical walls of the enclosure, steady state laminar regime is considered. The transport equations for continuity, momentum, energy and spices transfer are solved. The numerical results are reported for the effect of Richardson number, Lewis number, and buoyancy ratio on the iso-contours of stream line, temperature, and concentration. In addition, the predicted results for both local and average Nusselt and Sherwood numbers are presented and discussed for various parametric conditions. This study was done for 0.1 <= Le <= 50 and Prandtl number Pr = 0.7. Through out the study the Grashof number and aspect ratio are kept constant at 10{sup 4} and 2 respectively and -10 <= N <= 10, while Richardson number has been varied from 0.01 to 10 to simulate forced convection dominated flow, mixed convection and natural convection dominated flow. (authors)

  6. Estimating Planetary Boundary Layer Heights from NOAA Profiler Network Wind Profiler Data

    Science.gov (United States)

    Molod, Andrea M.; Salmun, H.; Dempsey, M

    2015-01-01

    An algorithm was developed to estimate planetary boundary layer (PBL) heights from hourly archived wind profiler data from the NOAA Profiler Network (NPN) sites located throughout the central United States. Unlike previous studies, the present algorithm has been applied to a long record of publicly available wind profiler signal backscatter data. Under clear conditions, summertime averaged hourly time series of PBL heights compare well with Richardson-number based estimates at the few NPN stations with hourly temperature measurements. Comparisons with clear sky reanalysis based estimates show that the wind profiler PBL heights are lower by approximately 250-500 m. The geographical distribution of daily maximum PBL heights corresponds well with the expected distribution based on patterns of surface temperature and soil moisture. Wind profiler PBL heights were also estimated under mostly cloudy conditions, and are generally higher than both the Richardson number based and reanalysis PBL heights, resulting in a smaller clear-cloudy condition difference. The algorithm presented here was shown to provide a reliable summertime climatology of daytime hourly PBL heights throughout the central United States.

  7. Controls on Turbulent Mixing in a Strongly Stratified and Sheared Tidal River Plume

    Energy Technology Data Exchange (ETDEWEB)

    Jurisa, Joseph T.; Nash, Jonathan D.; Moum, James N.; Kilcher, Levi F.

    2016-08-01

    Considerable effort has been made to parameterize turbulent kinetic energy (TKE) dissipation rate ..epsilon.. and mixing in buoyant plumes and stratified shear flows. Here, a parameterization based on Kunze et al. is examined, which estimates ..epsilon.. as the amount of energy contained in an unstable shear layer (Ri < Ric) that must be dissipated to increase the Richardson number Ri = N2/S2 to a critical value Ric within a turbulent decay time scale. Observations from the tidal Columbia River plume are used to quantitatively assess the relevant parameters controlling ..epsilon.. over a range of tidal and river discharge forcings. Observed ..epsilon.. is found to be characterized by Kunze et al.'s form within a factor of 2, while exhibiting slightly decreased skill near Ri = Ric. Observed dissipation rates are compared to estimates from a constant interfacial drag formulation that neglects the direct effects of stratification. This is found to be appropriate in energetic regimes when the bulk-averaged Richardson number Rib is less than Ric/4. However, when Rib > Ric/4, the effects of stratification must be included. Similarly, ..epsilon.. scaled by the bulk velocity and density differences over the plume displays a clear dependence on Rib, decreasing as Rib approaches Ric. The Kunze et al. ..epsilon.. parameterization is modified to form an expression for the nondimensional dissipation rate that is solely a function of Rib, displaying good agreement with the observations. It is suggested that this formulation is broadly applicable for unstable to marginally unstable stratified shear flows.

  8. A comparison of boundary-layer heights inferred from wind-profiler backscatter profiles with diagnostic calculations using regional model forecasts

    Energy Technology Data Exchange (ETDEWEB)

    Baltink, H.K.; Holtslag, A.A.M. [Royal Netherlands Meteorological Inst., KNMI, De Bilt (Netherlands)

    1997-10-01

    From October 1994 through January 1997 the Tropospheric Energy Budget Experiment (TEBEX) was executed by KNMI. The main objectives are to study boundary layer processes and cloud variability on the sub-grid scale of present Global Climate Models and to improve the related sub-grid parametrizations. A suite of instruments was deployed to measure a large number of variables. Measurements to characterize ABL processes were focussed around the 200 m high meteorological observation tower of the KNMI in Cabauw. In the framework of TEBEX a 1290 MHz wind-profiler/RASS was installed in July 1994 at 300 m from tower. Data collected during TEBEX are used to assess the performance of a Regional Atmospheric Climate Model (RACMO). This climate model runs also in a operational forecast mode once a day. The diagnostic ABL-height (h{sub model}) is calculated from the RACMO forecast output. A modified Richardson`s number method extended with an excess parcel temperature is applied for all stability conditions. We present the preliminary results of a comparison of h{sub model} from forecasts with measured h{sub TS} derived from profiler and sodar data for July 1995. (au)

  9. Mixing height derived from the DMI-HIRLAM NWP model, and used for ETEX dispersion modelling

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, J.H.; Rasmussen, A. [Danish Meteorological Inst., Copenhagen (Denmark)

    1997-10-01

    For atmospheric dispersion modelling it is of great significance to estimate the mixing height well. Mesoscale and long-range diffusion models using output from numerical weather prediction (NWP) models may well use NWP model profiles of wind, temperature and humidity in computation of the mixing height. This is dynamically consistent, and enables calculation of the mixing height for predicted states of the atmosphere. In autumn 1994, the European Tracer Experiment (ETEX) was carried out with the objective to validate atmospheric dispersion models. The Danish Meteorological Institute (DMI) participates in the model evaluations with the Danish Emergency Response Model of the Atmosphere (DERMA) using NWP model data from the DMI version of the High Resolution Limited Area Model (HIRLAM) as well as from the global model of the European Centre for Medium-Range Weather Forecast (ECMWF). In DERMA, calculation of mixing heights are performed based on a bulk Richardson number approach. Comparing with tracer gas measurements for the first ETEX experiment, a sensitivity study is performed for DERMA. Using DMI-HIRLAM data, the study shows that optimum values of the critical bulk Richardson number in the range 0.15-0.35 are adequate. These results are in agreement with recent mixing height verification studies against radiosonde data. The fairly large range of adequate critical values is a signature of the robustness of the method. Direct verification results against observed missing heights from operational radio-sondes released under the ETEX plume are presented. (au) 10 refs.

  10. Acoustic detection of momentum transfer during the abrupt transition from a laminar to a turbulent atmospheric boundary layer1

    International Nuclear Information System (INIS)

    Schubert, J.F.

    1977-01-01

    Acoustic sounder measurements of a vertical profile of the abrupt transition from a laminar to a turbulent atmospheric boundary layer were compared with meteorological measurements made at 10 and 137 m on an instrumented tower. Sounder data show that conditions necessary for the onset of the momentum burst phenomenon exist sometime during a clear afternoon when heat flux changes sign and the planetary surface cools. Under these conditions, the lowest part of the atmospheric boundary layer becomes stable. Prior to this situation, the entire boundary layer is in turbulent motion from surface heating. The boundary layer is then an effective barrier for all fluxes, and as the maximum flux Richardson number is reached at some height close to but above the surface, turbulence is dampened and a laminar layer forms. The profile of this layer is recorded by the sounder. Surface temperature drops, a strong wind shear develops, and the Richardson number decreases below its critical value (Ri/sub cr/<0.25). Subsequently, the laminar layer is eroded by turbulence from above, and with a burst of momentum and heat, it eventually reaches the ground

  11. Multitude scaling laws in axisymmetric turbulent wake

    Science.gov (United States)

    Layek, G. C.; Sunita

    2018-03-01

    We establish theoretically multitude scaling laws of a self-similar (statistical) axisymmetric turbulent wake. At infinite Reynolds number limit, the flow evolves as general power law and a new exponential law of streamwise distance, consistent with the criterion of equilibrium similarity hypothesis. We found power law scalings for components of the homogeneous dissipation rate (ɛ) obeying the non-Richardson-Kolmogorov cascade as ɛu˜ku3 /2/(l R elm ) , ɛv˜kv3 /2/l , kv˜ku/R el2 m, 0 stress, l is the local length scale, and Rel is the Reynolds number. The Richardson-Kolmogorov cascade corresponds to m = 0. For m ≈ 1, the power law agrees with non-equilibrium scaling laws observed in recent experiments of the axisymmetric wake. On the contrary, the exponential scaling law follows the above dissipation law with different regions of existence for power index m = 3. At finite Reynolds number with kinematic viscosity ν, scalings obey the dissipation laws ɛu ˜ νku/l2 and ɛv ˜ νkv/l2 with kv˜ku/R eln. The value of n is preferably 0 and 2. Different possibilities of scaling laws and symmetry breaking process are discussed at length.

  12. Optimal energy growth in a stably stratified shear flow

    Science.gov (United States)

    Jose, Sharath; Roy, Anubhab; Bale, Rahul; Iyer, Krithika; Govindarajan, Rama

    2018-02-01

    Transient growth of perturbations by a linear non-modal evolution is studied here in a stably stratified bounded Couette flow. The density stratification is linear. Classical inviscid stability theory states that a parallel shear flow is stable to exponentially growing disturbances if the Richardson number (Ri) is greater than 1/4 everywhere in the flow. Experiments and numerical simulations at higher Ri show however that algebraically growing disturbances can lead to transient amplification. The complexity of a stably stratified shear flow stems from its ability to combine this transient amplification with propagating internal gravity waves (IGWs). The optimal perturbations associated with maximum energy amplification are numerically obtained at intermediate Reynolds numbers. It is shown that in this wall-bounded flow, the three-dimensional optimal perturbations are oblique, unlike in unstratified flow. A partitioning of energy into kinetic and potential helps in understanding the exchange of energies and how it modifies the transient growth. We show that the apportionment between potential and kinetic energy depends, in an interesting manner, on the Richardson number, and on time, as the transient growth proceeds from an optimal perturbation. The oft-quoted stabilizing role of stratification is also probed in the non-diffusive limit in the context of disturbance energy amplification.

  13. On the concept of material strength and first simulations of asteroid disruption with explicit formation of spinning aggregates in the gravity regime

    Science.gov (United States)

    Michel, P.; Richardson, D. C.

    2007-08-01

    understanding on the physical properties of these objects, and to check whether our theoretical and numerical works are valid. References Michel P., BenzW., Tanga P., Richardson D.C. 2001. Collisions and gravitational reaccumulation: forming asteroid families and satellites. Science 294 1696-1700 (+cover of the journal). Michel P., Benz W., Tanga P., Richardson D.C. 2002. Formation of asteroid families by catastrophic disruption: simulations with fragmentation and gravitational reaccumulation. Icarus 160, 10-23. Michel P., Benz W., Richardson D.C. 2003. Fragmented parent bodies as the origin of asteroid families. Nature 421, 608-611 (+cover of the journal). Michel P., BenzW., Richardson D.C. 2004a. Disruption of pre-shattered parent bodies. Icarus 168, 420-432. Michel P., Benz W., Richardson D.C. 2004b. Catastrophic disruptions and family formation: a review of numerical simulations including both fragmentation and gravitational reaccumulations. Planet. Space. Sci. 52, 1109-1117.

  14. Prediction of stably stratified homogeneous shear flows with second-order turbulence models

    International Nuclear Information System (INIS)

    Pereira, J C F; Rocha, J M P

    2010-01-01

    The present study investigated the role of pressure-correlation second-order turbulence modelling schemes on the predicted behaviour of stably stratified homogeneous vertical-sheared turbulence. The pressure-correlation terms were modelled with a nonlinear formulation (Craft 1991), which was compared with a linear pressure-strain model and the 'isotropization of production' model for the pressure-scalar correlation. Two additional modelling issues were investigated: the influence of the buoyancy term in the kinetic energy dissipation rate equation and the time scale in the thermal production term in the scalar variance dissipation equation. The predicted effects of increasing the Richardson number on turbulence characteristics were compared against a comprehensive set of direct numerical simulation databases. The linear models provide a broadly satisfactory description of the major effects of the Richardson number on stratified shear flow. The buoyancy term in the dissipation equation of the turbulent kinetic energy generates excessively low levels of dissipation. For moderate and large Richardson numbers, the term yields unrealistic linear oscillations in the shear and buoyancy production terms, and therefore should be dropped in this flow (or at least their coefficient c ε3 should be substantially reduced from its standard value). The mechanical dissipation time scale provides marginal improvements in comparison to the scalar time scale in the production. The observed inaccuracy of the linear model in predicting the magnitude of the effects on the velocity anisotropy was demonstrated to be attributed mainly to the defective behaviour of the pressure-correlation model, especially for stronger stratification. The turbulence closure embodying a nonlinear formulation for the pressure-correlations and specific versions of the dissipation equations failed to predict the tendency of the flow to anisotropy with increasing stratification. By isolating the effects of the

  15. The distribution of the barrier height in Al–TiW–Pd2Si/n-Si Schottky diodes from I–V–T measurements

    International Nuclear Information System (INIS)

    Dökme, Ilbilge; Altındal, Şemsettin; Afandiyeva, Izzet M

    2008-01-01

    The forward and reverse bias current–voltage (I–V) characteristics of Al–TiW–Pd 2 Si/n-Si Schottky barrier diodes (SBDs) were measured in the temperature range of 300–400 K. The estimated zero-bias barrier height Φ B0 and the ideality factor n assuming thermionic emission (TE) theory show a strong temperature dependence. While n decreases, Φ B0 increases with increasing temperature. The Richardson plot is found to be linear in the temperature range measured, but the activation energy value of 0.378 eV and the Richardson constant (A*) value of 15.51 A cm −2 K −2 obtained in this plot are much lower than the known values. Such behavior is attributed to Schottky barrier inhomogeneities by assuming a Gaussian distribution of barrier heights (BHs) due to BH inhomogeneities that prevail at the interface. Also, the Φ B0 versus q/2kT plot was drawn to obtain evidence of a Gaussian distribution of the BHs, and Φ B0 = 0.535 eV and σ 0 = 0.069 V for the mean BH and zero-bias standard deviation, respectively, have been obtained from this plot. Thus, the modified ln(I 0 /T 2 ) − q 2 σ 2 0 /2k 2 T 2 versus q/kT plot gives Φ B0 and A* as 0.510 eV and 121.96 A cm −2 K −2 , respectively. This value of the Richardson constant 121.96 A cm −2 K −2 is very close to the theoretical value of 120 A K −2 cm −2 for n-type Si. Hence, it has been concluded that the temperature dependence of the forward I–V characteristics of the Al–TiW–Pd 2 Si/n-Si Schottky barrier diodes can be successfully explained on the basis of a thermionic emission mechanism with a Gaussian distribution of the BHs

  16. Mixed convection in a lid-driven square cavity with partial slip

    International Nuclear Information System (INIS)

    Ismael, Muneer A.; Pop, Ioan; Chamkha, Ali J.

    2014-01-01

    Steady laminar mixed convection inside a lid-driven square cavity filled with water is studied numerically. The lid is due to the movement of the isothermal top and bottom walls which are maintained at T c and T h , respectively, with T h is higher than T c . A partial slip condition was imposed in these two moving walls. The vertical walls of the cavity are kept adiabatic. The appliance of the numerical analysis was USR finite difference method with upwind scheme treatments of the convective terms included in the momentum and energy equations. The studied relevant parameters were: the partial slip parameter S (0-∞); Richardson number Ri (0.01-100) and the direction of the moving walls (λ t = 1, λ b = ±1). The results have showed that there are critical values for the partial slip parameter at which the convection is declined. (authors)

  17. The hologram principles and techniques

    CERN Document Server

    Richardson, Martin J

    2018-01-01

    Written by Martin Richardson (an acclaimed leader and pioneer in the field) and John Wiltshire, The Hologram: Principles and Techniques is an important book that explores the various types of hologram in their multiple forms and explains how to create and apply the technology. The authors offer an insightful overview of the currently available recording materials, chemical formulas, and laser technology that includes the history of phase imaging and laser science. Accessible and comprehensive, the text contains a step-by-step guide to the production of holograms. In addition, The Hologram outlines the most common problems encountered in producing satisfactory images in the laboratory, as well as dealing with the wide range of optical and chemical techniques used in commercial holography. The Hologram is a well-designed instructive tool, involving three distinct disciplines: physics, chemistry, and graphic arts. This vital resource offers a guide to the development and understanding of the recording of mater...

  18. On the Onset Frequency of Metric Type II Radio Bursts and the Longitudinal Extent of the Associated SEP Events

    Science.gov (United States)

    Makela, P. A.; Gopalswamy, N.; Yashiro, S.; Thakur, N.; Akiyama, S.; Xie, H.

    2017-12-01

    In a recent study Gopalswamy et al. (2017, J. Phys. Conf. Ser., Proc. 16th AIAC) found that the ground level enhancements (GLEs), regular solar energetic particle (SEP) events and filament eruption (FE) associated SEP events have distinct average starting frequencies of the associated type II bursts, although the distributions overlap. They also found that the initial acceleration of the coronal mass ejections (CMEs) associated with the three groups were distinct. Based on these earlier results emphasizing a hierarchical relationship of CME kinematics and SEP events, we studied the possible dependence between the longitudinal spread of the SEP events and the onset frequency of metric type II. The studied >25 MeV SEP events are from the list of Richardson et al. (2014, Sol. Phys. 289) covering the first seven years of the STEREO mission. However, our preliminary results show only a weak correlation between the extent of the SEP event and the onset frequency of the metric type II radio burst.

  19. Step edge influence on barrier height and contact area in vertical heterojunctions between epitaxial graphene and n-type 4H-SiC

    International Nuclear Information System (INIS)

    Tadjer, M. J.; Nyakiti, L. O.; Robinson, Z.; Anderson, T. J.; Myers-Ward, R. L.; Wheeler, V. D.; Eddy, C. R.; Gaskill, D. K.; Koehler, A. D.; Hobart, K. D.; Kub, F. J.

    2014-01-01

    Vertical rectifying contacts of epitaxial graphene grown by Si sublimation on the Si-face of 4H-SiC epilayers were investigated. Forward bias preferential conduction through the step edges was correlated by linear current density normalization. This phenomenon was observed on samples with 2.7–5.8 monolayers of epitaxial graphene as determined by X-ray photoelectron spectroscopy. A modified Richardson plot was implemented to extract the barrier height (0.81 eV at 290 K, 0.99 eV at 30 K) and the electrically dominant SiC step length of a Ti/Al contact overlapping a known region of approximately 0.52 μm wide SiC terraces

  20. Numerical Investigation of Fluid Flow and Heat Transfer Inside a 2D Enclosure with Three Hot Obstacles on the Ramp under the Influence of a Magnetic Field

    Directory of Open Access Journals (Sweden)

    M. M. Keshtkar

    2017-06-01

    Full Text Available This paper focuses on solving the fluid flow and heat transfer equations inside a two-dimensional square enclosure containing three hot obstacles affected by gravity and magnetic force placed on a ramp using Boltzmann method (LBM applying multiple relaxation times (MRT. Although, the Lattice Boltzmann with MRT is a complex technique, it is a relatively new, stable, fast and high-accurate one. The main objective of this research was to numerically model the fluid flow and ultimately obtaining the velocity field, flow and temperature contour lines inside a two-dimensional enclosure. The results and their comparisons for different types of heat transfer revealed that free or forced heat transfer has a considerable impact on the heat transfer and stream lines. This can be controlled by modifying the Richardson number. It is revealed that changing the intensity of the magnetic field (Hartman number has an appreciable effect on the heat transfer.

  1. An experimental and numerical study of the atmospheric stability impact on wind turbine wakes

    DEFF Research Database (Denmark)

    Machefaux, Ewan; Larsen, Gunner Chr.; Koblitz, Tilman

    2016-01-01

    campus test site. Wake measurements are averaged within a mean wind speed bin of 1 m s1 and classified according to atmospheric stability using three different metrics: the Obukhov length, the Bulk–Richardson number and the Froude number. Three test cases are subsequently defined covering various...... atmospheric conditions. Simulations are carried out using large eddy simulation and actuator disk rotor modeling. The turbulence properties of the incoming wind are adapted to the thermal stratification using a newly developed spectral tensor model that includes buoyancy effects. Discrepancies are discussed......In this paper, the impact of atmospheric stability on a wind turbine wake is studied experimentally and numerically. The experimental approach is based on full-scale (nacelle based) pulsed lidar measurements of the wake flow field of a stall-regulated 500 kW turbine at the DTU Wind Energy, Risø...

  2. Optical and Electrical Properties of Al/(p)Bi2S3 Schottky Junction

    International Nuclear Information System (INIS)

    Kachari, T.; Wary, G.; Rahman, A.

    2010-01-01

    Thin film Al/(p)Bi 2 S 3 Schottky junctions were prepared by vacuum evaporation under pressure 10 -6 Torr. The p-type Bi 2 S 3 thin films with acceptor concentration (3.36-7.33)x10 16 /cm 3 were obtained by evaporating 'In' along with Bi 2 S 3 powder and then annealing the films at 453K for 5 hours. Different junction-parameters such as ideality factor, barrier height, effective Richardson's constant, short-circuit current, etc. were determined from I-V characteristics. The junctions exhibited rectifying I-V characteristics and also photovoltaic effect. Ideality factor was found to decrease with the increase of temperature. Proper doping, annealing, and hydrogenation are necessary to reduce the series resistance so as to achieve high carrier efficiency. More works are being carried out in this direction.

  3. Dynamical Response of Catalytic Systems in a CS Corrected Environmental Transmission Electron Microscope

    DEFF Research Database (Denmark)

    Hansen, Thomas Willum; Dunin-Borkowski, Rafal E.; Boothroyd, Chris

    2010-01-01

    . In a catalytic reactor, the particles tend to sinter under reaction conditions resulting in the formation of larger particles and a loss of catalytic activity. Several models of sintering in different systems have been put forward [4,5]. However, most investigations have been post mortem studies, revealing only...... energies and energy barriers for sintering processes can be studied. The surface structures of catalytic materials are highly dependent on the surrounding atmosphere. The combined capabilities of ETEM and image CS correction provide unique possibilities to study this relationship. However, in order...... as function of Ar pressure in the pole piece gap. References [1] I. Chorkendorff and J.W. Niemantsverdriet, Concepts of Modern Catalysis and Kinetics, Wiley-VCH, Weinheim, 2003. [2] www.nacatsoc.org [3] A.K. Datye, J. Catal. 216 (2003) 144. [4] J.T. Richardson and J.G. Crump, J. Catal. 56 (1979) 417. [5] C. H...

  4. Prediction of barrier inhomogeneities and carrier transport in Ni-silicided Schottky diode

    International Nuclear Information System (INIS)

    Saha, A.R.; Dimitriu, C.B.; Horsfall, A.B.; Chattopadhyay, S.; Wright, N.G.; O'Neill, A.G.; Maiti, C.K.

    2006-01-01

    Based on Quantum Mechanical (QM) carrier transport and the effects of interface states, a theoretical model has been developed to predict the anomalous current-voltage (I-V) characteristics of a non-ideal Ni-silicided Schottky diode at low temperatures. Physical parameters such as barrier height, ideality factor, series resistance and effective Richardson constant of a silicided Schottky diode were extracted from forward I-V characteristics and are subsequently used for the simulation of both forward and reverse I-V characteristics using a QM transport model in which the effects of interface state and bias dependent barrier reduction are incorporated. The present analysis indicates that the effects of barrier inhomogeneity caused by incomplete silicide formation at the junction and the interface states may change the conventional current transport process, leading to anomalous forward and reverse I-V characteristics for the Ni-silicided Schottky diode

  5. Procedure for obtaining visas for Switzerland and France - Signature rights

    CERN Multimedia

    2016-01-01

    In accordance with the Status Agreements with CERN, Switzerland and France facilitate the entry of members of the Organization’s personnel on to their territories. Where relevant, detailed procedures for obtaining visas apply.   Within the framework of those procedures, only the following individuals are authorised to initiate the Note verbale procedure as well as to sign the Official Invitation Letters and the Conventions d’accueil. Kirsti ASPOLA (EP – CMO) Maria BARROSO LOPEZ (IT – DI) Catherine BRANDT (DG – DI) Michelle CONNOR (TH – GS) Gaëlle DUPERRIER (EP – AGS) Patrick FASSNACHT (EP – ADO) Fernando FERNANDEZ SAVORGNANO (HR – TA) Nathalie GOURIOU (EP – AGS) Nathalie GRÜB (EP – AGS) Laurie HEMERY (BE – ASR) Cécile NOELS (ATS – DO) Tania PARDO (EP – AGS) Maria QUINTAS (HR – TA) Kate RICHARDSON (EP –  A...

  6. Procedure for obtaining visas for Switzerland and France - Signature rights

    CERN Multimedia

    2014-01-01

    In accordance with the Status Agreements with CERN, Switzerland and France facilitate the entry of members of the Organization’s personnel onto their territories. Where relevant, detailed procedures for obtaining visas apply.   Within the framework of those procedures, only the following individuals are authorised to initiate the note verbale procedure as well as to sign the Official Invitation Letters and the Conventions d’accueil. 1. Kirsti ASPOLA (PH – CMO) 2. Catherine BRANDT (DG – IR) 3. Oliver BRÜNING (BE – ABP) 4. Michelle CONNOR (PH – AGS) 5. Patrick FASSNACHT (PH – ADO) 6. Fernando FERNANDEZ SAVORGNANO (HR – TA) 7. David FOSTER (IT – DI) 8. Nathalie GRÜB (PH – AGS) 9. Cécile NOELS (DG – DI) 10. Maria QUINTAS (HR – TA) 11. Kate RICHARDSON (PH –  AGS) 12. Jeanne ROSTANT (PH – AGS) 13. José SALICIO-DIEZ (...

  7. Procedure for obtaining visas for Switzerland and France - Signature rights

    CERN Multimedia

    2016-01-01

    In accordance with the Status Agreements with CERN, Switzerland and France facilitate the entry of members of the Organization’s personnel on to their territories. Where relevant, detailed procedures for obtaining visas apply.   Within the framework of those procedures, only the following individuals are authorised to initiate the Note verbale procedure as well as to sign the Official Invitation Letters and the Conventions d’accueil. Kirsti ASPOLA (EP – CMO) Maite BARROSO LOPEZ (IT – DI) Catherine BRANDT (DG – DI) Michelle CONNOR (TH – GS) Gaëlle DUPERRIER (EP – AGS) Patrick FASSNACHT (EP – ADO) Fernando FERNANDEZ SAVORGNANO (HR – TA) Nathalie GRÜB (EP – AGS) Laurie HEMERY (BE – ASR) Cécile NOELS (ATS – DO) Tania PARDO (EP – AGS) Maria QUINTAS (HR – TA) Kate RICHARDSON (EP –  AGS) Jeanne ROSTANT (TH – GS)...

  8. Self-similar two-particle separation model

    DEFF Research Database (Denmark)

    Lüthi, Beat; Berg, Jacob; Ott, Søren

    2007-01-01

    .g.; in the inertial range as epsilon−1/3r2/3. Particle separation is modeled as a Gaussian process without invoking information of Eulerian acceleration statistics or of precise shapes of Eulerian velocity distribution functions. The time scale is a function of S2(r) and thus of the Lagrangian evolving separation......We present a new stochastic model for relative two-particle separation in turbulence. Inspired by material line stretching, we suggest that a similar process also occurs beyond the viscous range, with time scaling according to the longitudinal second-order structure function S2(r), e....... The model predictions agree with numerical and experimental results for various initial particle separations. We present model results for fixed time and fixed scale statistics. We find that for the Richardson-Obukhov law, i.e., =gepsilont3, to hold and to also be observed in experiments, high Reynolds...

  9. An introduction to quiver representations

    CERN Document Server

    Derksen, Harm

    2017-01-01

    This book is an introduction to the representation theory of quivers and finite dimensional algebras. It gives a thorough and modern treatment of the algebraic approach based on Auslander-Reiten theory as well as the approach based on geometric invariant theory. The material in the opening chapters is developed starting slowly with topics such as homological algebra, Morita equivalence, and Gabriel's theorem. Next, the book presents Auslander-Reiten theory, including almost split sequences and the Auslander-Reiten transform, and gives a proof of Kac's generalization of Gabriel's theorem. Once this basic material is established, the book goes on with developing the geometric invariant theory of quiver representations. The book features the exposition of the saturation theorem for semi-invariants of quiver representations and its application to Littlewood-Richardson coefficients. In the final chapters, the book exposes tilting modules, exceptional sequences and a connection to cluster categories. The book is su...

  10. Trends in rainfall erosivity (1955-2006) over the Ebro basin; Tendencias en la erosividad de la lluvia (1955-2006) en la cuenca del Ebro

    Energy Technology Data Exchange (ETDEWEB)

    Angulo Martinez, M.; Vicente Serrano, S. M.; Begueria, S.

    2009-07-01

    Rainfall is one of the main factors affecting soil erosion. This effect is summarized in the concept or rainfall erosivity which involves the drop size distribution and kinetic energy of an event, its duration and intensity, and the runoff that generates. To calculate rainfall erosivity several indices can be applied. The most extensively used is the R factor of the Revised Universal soil Loss Equation (RUSLE). To compute this index continuous rainfall data are needed. This kind of data is difficult to obtain with a good spatial and temporal coverage. In this work, daily rainfall records have been converted into daily rainfall erosivity data. For this objective, we used the Richardson et al. (1983) exponential relationship between rainfall volume and rainfall erosivity to create the Daily Rainfall Erosivity Model (DREM). (Author) 4 refs.

  11. Strong Interactions, (De)coherence and Quarkonia

    CERN Document Server

    Bellucci, Stefano; Tiwari, Bhupendra Nath

    2011-01-01

    Quarkonia are the central objects to explore the non-perturbative nature of non-abelian gauge theories. We describe the confinement-deconfinement phases for heavy quarkonia in a hot QCD medium and thereby the statistical nature of the inter-quark forces. In the sense of one-loop quantum effects, we propose that the "quantum" nature of quark matters follows directly from the thermodynamic consideration of Richardson potential. Thereby we gain an understanding of the formation of hot and dense states of quark gluon plasma matter in heavy ion collisions and the early universe. In the case of the non-abelian theory, the consideration of the Sudhakov form factor turns out to be an efficient tool for soft gluons. In the limit of the Block-Nordsieck resummation, the strong coupling obtained from the Sudhakov form factor yields the statistical nature of hadronic bound states, e.g. kaons and Ds particles.

  12. In-situ analysis of microwave conductivity and impedance spectroscopy for evaluation of charge carrier dynamics at interfaces

    Science.gov (United States)

    Choi, Wookjin; Inoue, Junichi; Tsutsui, Yusuke; Sakurai, Tsuneaki; Seki, Shu

    2017-11-01

    A unique concerted analysis comprising non-contact microwave conductivity measurements and impedance spectroscopy was developed to simultaneously assess the charge carrier mobility and injection barriers. The frequency dependence of the microwave conductivity as well as the electrical current was analyzed by applying sinusoidal voltage to determine the equivalent circuit parameters. Based on the temperature dependence of the circuit parameters, the energy of the injection barrier was estimated to be 0.4 eV with the Richardson-Schottky model, and the band-like transport was confirmed with the negative temperature coefficient with the β value of 1.4 in the intra-layer conduction of C8-BTBT. In contrast, the increase in the resistance of the C8-BTBT layer with decreasing temperature implied the occurrence of hopping-like transport in the inter-layer conduction of C8-BTBT.

  13. Isovector pairing effect on nuclear moment of inertia at finite temperature in N = Z even–even systems

    International Nuclear Information System (INIS)

    Ami, I.; Fellah, M.; Allal, N.H.; Benhamouda, N.; Oudih, M.R.; Belabbas, M.

    2011-01-01

    Expressions of temperature-dependent perpendicular (ℑ⊥) and parallel (ℑ‖) moments of inertia, including isovector pairing effects, have been established using the cranking method. They are derived from recently proposed temperature-dependent gap equations. The obtained expressions generalize the conventional finite-temperature BCS (FTBCS) ones. Numerical calculations have been carried out within the framework of the schematic Richardson model as well as for nuclei such as N = Z, using the single-particle energies and eigenstates of a deformed Woods–Saxon mean-field. ℑ⊥ and ℑ‖ have been studied as a function of the temperature. It has been shown that the isovector pairing effect on both the perpendicular and parallel moments of inertia is non-negligible at finite temperature. These correlations must thus be taking into account in studies of warm rotating nuclei in the N ≃ Z region. (author)

  14. Estimation of seasonal atmospheric stability and mixing height by using different schemes

    International Nuclear Information System (INIS)

    Essa, K.S.M.; Embaby, M.; Mubarak, F.; Kamel, I.

    2007-01-01

    Different atmospheric stability schemes were used to characterize the plume growth (dispersion coefficients σ) in the lateral and vertical directions to determine the concentration distribution of pollutants through the PBL. The PBL is the region in which surface friction has a large effect on the mixing of pollutants. It is also suffer large fluctuation in temperature and wind and its depth (mixing depth) changes over a diurnal cycle. In this study, four months of surface meteorological parameters were used (to represent different seasons) to determine seasonal stability, classification. Five different stability schemes were estimated based on temperature gradient, standard deviation of the horizontal wind direction fluctuation, gradient and Bulk Richardson numbers and Monin-Obukhov length. Friction velocity, (u * ) for each stability scheme was estimated for characterizing the hourly, mixing height for each stability class. Also, plume rise was estimated for each stability class depending on the availability of meteorological parameters

  15. Solution of the fully fuzzy linear systems using iterative techniques

    International Nuclear Information System (INIS)

    Dehghan, Mehdi; Hashemi, Behnam; Ghatee, Mehdi

    2007-01-01

    This paper mainly intends to discuss the iterative solution of fully fuzzy linear systems which we call FFLS. We employ Dubois and Prade's approximate arithmetic operators on LR fuzzy numbers for finding a positive fuzzy vector x-tilde which satisfies A-tildex-tilde=b, where A-tilde and b-tilde are a fuzzy matrix and a fuzzy vector, respectively. Please note that the positivity assumption is not so restrictive in applied problems. We transform FFLS and propose iterative techniques such as Richardson, Jacobi, Jacobi overrelaxation (JOR), Gauss-Seidel, successive overrelaxation (SOR), accelerated overrelaxation (AOR), symmetric and unsymmetric SOR (SSOR and USSOR) and extrapolated modified Aitken (EMA) for solving FFLS. In addition, the methods of Newton, quasi-Newton and conjugate gradient are proposed from nonlinear programming for solving a fully fuzzy linear system. Various numerical examples are also given to show the efficiency of the proposed schemes

  16. The products of intertextuality: The value of student adaptations in a literature course

    Directory of Open Access Journals (Sweden)

    Misty Krueger

    2015-09-01

    Full Text Available The essay explores a pedagogy of adaptation that focuses on examining intertextuality and engaging students in textual production through the creation of an adaptation. The paper discusses the success of assigning an adaptation project in an upper-level, third-year literature course taught at a small university. It examines student adaptations of writings by William Shakespeare, Jane Austen, Samuel Richardson, Henry Fielding, Mary Shelley, and Ben H. Winters and of existing film adaptations of Sense and Sensibility and Frankenstein. I link student projects to critical concepts such as re-vision and multimodality, and disciplines such as literary studies and the digital humanities. I also analyze how the projects reflect students' interests in popular culture and fandom.

  17. Towards an optimal model for a bistable nematic liquid crystal display device

    KAUST Repository

    Cummings, L. J.

    2013-03-13

    Bistable liquid crystal displays offer the potential for considerable power savings compared with conventional (monostable) LCDs. The existence of two stable field-free states that are optically distinct means that contrast can be maintained in a display without an externally applied electric field. An applied field is required only to switch the device from one state to the other, as needed. In this paper we examine a theoretical model of a possible bistable device, originally proposed by Cummings and Richardson (Euro J Appl Math 17:435-463 2006), and explore means by which it may be optimized, in terms of optical contrast, manufacturing considerations, switching field strength, and switching times. The compromises inherent in these conflicting design criteria are discussed. © 2013 Springer Science+Business Media Dordrecht.

  18. Preparation of the study of the quark-gluon plasma in ALICE: the V0 detector and the low masses resonances in the muon spectrometer

    International Nuclear Information System (INIS)

    Nendaz, F.

    2009-09-01

    The ALICE (A Large Ion Collider Experiment) experiment at LHC will study from 2010 the quark-gluon plasma (QGP), phase of the matter in which quarks and gluons are deconfined. The work presented here was done within the ALICE collaboration, for preparing the analysis of the incoming experimental data. Besides a theoretical approach of the QGP and of the chiral symmetry, we develop three experimental aspects: the V0 sub-detector, the study of the low mass mesons and the deconvolution. First, we detail the measures of luminosity and multiplicity that can be done with the V0. We then develop the study of the dimuons in the muon spectrometer. We concentrate on the low masses mesons: the rho, the omega and the phi. Finally, we present a method for improving the spectrometer data: the Richardson-Lucy deconvolution. (author)

  19. A comparative study of mixed convection and its effect on partially active thermal zones in a two sided lid-driven cavity filled with nanofluid

    Directory of Open Access Journals (Sweden)

    Sumit Malik

    2016-09-01

    Full Text Available In the present study, a two sided lid-driven mixed convection nanofluid flow with discrete heat sources have been numerically investigated. A two dimensional computational visualization technique is used to study the flow behavior using four different cases; depending on the direction of moving vertical walls with fixed upper and lower walls. Two discrete heat sources of equal lengths are taken on the lower wall and the rest of it is kept insulated. The other walls are kept at constant low temperature. The effect of flow governing parameters such as Reynolds number 1⩽Re⩽100, Richardson number 0.1⩽Ri⩽10 and solid volume fraction 0.0⩽ϕ⩽0.2 with Prandtl number Pr=6.2 is studied to understand the fluid flow pattern and the heat transfer effect using isotherms and average Nusselt number.

  20. Deconvolution for the localization of sound sources using a circular microphone array

    DEFF Research Database (Denmark)

    Tiana Roig, Elisabet; Jacobsen, Finn

    2013-01-01

    During the last decade, the aeroacoustic community has examined various methods based on deconvolution to improve the visualization of acoustic fields scanned with planar sparse arrays of microphones. These methods assume that the beamforming map in an observation plane can be approximated by a c......-negative least squares, and the Richardson-Lucy. This investigation examines the matter with computer simulations and measurements....... that the beamformer's point-spread function is shift-invariant. This makes it possible to apply computationally efficient deconvolution algorithms that consist of spectral procedures in the entire region of interest, such as the deconvolution approach for the mapping of the acoustic sources 2, the Fourier-based non...

  1. Entropy Generation on Nanofluid Flow through a Horizontal Riga Plate

    Directory of Open Access Journals (Sweden)

    Tehseen Abbas

    2016-06-01

    Full Text Available In this article, entropy generation on viscous nanofluid through a horizontal Riga plate has been examined. The present flow problem consists of continuity, linear momentum, thermal energy, and nanoparticle concentration equation which are simplified with the help of Oberbeck-Boussinesq approximation. The resulting highly nonlinear coupled partial differential equations are solved numerically by means of the shooting method (SM. The expression of local Nusselt number and local Sherwood number are also taken into account and discussed with the help of table. The physical influence of all the emerging parameters such as Brownian motion parameter, thermophoresis parameter, Brinkmann number, Richardson number, nanoparticle flux parameter, Lewis number and suction parameter are demonstrated graphically. In particular, we conferred their influence on velocity profile, temperature profile, nanoparticle concentration profile and Entropy profile.

  2. Antagonist Characters in the Early Gothic Novel: A Matter Of Political Anxiety? = Erken Dönem Gotik Romanlarında Karşıt Karakterler

    Directory of Open Access Journals (Sweden)

    Christopher Thomas CAIRNEY

    2001-01-01

    Full Text Available During the eighteenth-century, the antagonist, previously the second most important character in a story, becomes, first in Richardson's Clarissa, and then under Gothic influence, the main character in the novel. This recalls the “heavy” villain of Elizabethan drama. The use to which the character is put by the author is both consciously and unconsciously political or ideological, at least in part. Under political influence, the antagonist can be classified as either “repentant” or “unrepentant,” with very different effects, as a New Historicist or Cultural Materialist analysis can reveal. The Gothic antagonist is set within the Gothic novel, and together with other conventions of the Gothic novel became the basis of later interpretations of the Gothic impulse in novels of various sub-genres, from oriental fiction and science fiction to the modern romance novel.

  3. Turbulence and pollutant transport in urban street canyons under stable stratification: a large-eddy simulation

    Science.gov (United States)

    Li, X.

    2014-12-01

    Thermal stratification of the atmospheric surface layer has strong impact on the land-atmosphere exchange of turbulent, heat, and pollutant fluxes. Few studies have been carried out for the interaction of the weakly to moderately stable stratified atmosphere and the urban canopy. This study performs a large-eddy simulation of a modeled street canyon within a weakly to moderately stable atmosphere boundary layer. To better resolve the smaller eddy size resulted from the stable stratification, a higher spatial and temporal resolution is used. The detailed flow structure and turbulence inside the street canyon are analyzed. The relationship of pollutant dispersion and Richardson number of the atmosphere is investigated. Differences between these characteristics and those under neutral and unstable atmosphere boundary layer are emphasized.

  4. Mixed convection flow past a horizontal plate

    Directory of Open Access Journals (Sweden)

    Savić Lj.

    2005-01-01

    Full Text Available The mixed convection flow past a horizontal plate being aligned through a small angle of attack to a uniform free stream will be considered in the limit of large Reynolds number and small Richardson number. Even a small angle of inclination of the wake is sufficient for the buoyancy force to accelerate the flow in the wake which causes a velocity overshoot in the wake. Moreover a hydrostatic pressure difference across the wake induces a correction to the potential flow which influences the inclination of the wake. Thus the wake and the correction of the potential flow have to be determined simultaneously. However, it turns out that solutions exist only if the angle of attack is sufficiently large. Solutions are computed numerically and the influence of the buoyancy on the lift coefficient is determined.

  5. The history of NATO TNF policy: The role of studies, analysis and exercises conference proceedings. Volume 2: Papers and presentations

    Energy Technology Data Exchange (ETDEWEB)

    Rinne, R.L.

    1994-02-01

    This conference was organized to study and analyze the role of simulation, analysis, modeling, and exercises in the history of NATO policy. The premise was not that the results of past studies will apply to future policy, but rather that understanding what influenced the decision process -- and how -- would be of value. The structure of the conference was built around discussion panels. The panels were augmented by a series of papers and presentations focusing on particular TNF events, issues, studies, or exercises. The conference proceedings consist of three volumes. Volume 1 contains the conference introduction, agenda, biographical sketches of principal participants, and analytical summary of the presentations and panels. This volume contains a short introduction and the papers and presentations from the conference. Volume 3 contains selected papers by Brig. Gen. Robert C. Richardson III (Ret.). Individual papers in this volume were abstracted and indexed for the database.

  6. Quantum phase diagram of the integrable px+ipy fermionic superfluid

    DEFF Research Database (Denmark)

    Rombouts, Stefan; Dukelsky, Jorge; Ortiz, Gerardo

    2010-01-01

    transition, separating a strong-pairing from a weak-pairing phase. The mean-field solution allows to connect these results to other models with px+ipy pairing order. We define an experimentally accessible characteristic length scale, associated with the size of the Cooper pairs, that diverges......We determine the zero-temperature quantum phase diagram of a px+ipy pairing model based on the exactly solvable hyperbolic Richardson-Gaudin model. We present analytical and large-scale numerical results for this model. In the continuum limit, the exact solution exhibits a third-order quantum phase...... at the transition point, indicating that the phase transition is of a confinement-deconfinement type without local order parameter. We propose an experimental measurement to detect the transition. We show that this phase transition is not limited to the px+ipy pairing model but can be found in any representation...

  7. Exploring interepistemological encounters in international HE at the intersection of ideologies of neoliberalism and ethical globalization

    DEFF Research Database (Denmark)

    Wadsholt, Tanja Kanne

    and the crisis in Higher Education." Qui Parle 20 (1):35-47. Bourdieu, Pierre. 1977. Outline of a Theory of Practice. Cambridge: Polity Press. Bourdieu, Pierre. 1986. "The Forms of Capital." In Handbook of Theory and Research for the Sociology of Education, edited by J. Richardson. New York: Greenwood. Bourdieu....... Passeron. 1990. Reproduction in Education, Society and Culture. 2 ed. London etc: Sage. Calhoun, C. 2006. "The University and the public good." Thesis Eleven 84 (1). Levinas, E. 1996. "Is Ontology Fundamental?" In Emmanuel Levinas: Basic Philosophical Writings, edited by Bernasconi, Critchley and Peperzak...... of the university, e.g. “the entrepreneurial university” (Barnett 2012) or “the global university” (Biesta 2011) in its external relation to society defined by its preoccupation with the economic and technical development of society and with matching the needs of the labor marked (e.g.Rhoads and Szelenyi 2011...

  8. Double diffusive magnetohydrodynamic heat and mass transfer of nanofluids over a nonlinear stretching/shrinking sheet with viscous-Ohmic dissipation and thermal radiation

    Directory of Open Access Journals (Sweden)

    Dulal Pal

    2017-03-01

    Full Text Available The study of magnetohydrodynamic (MHD convective heat and mass transfer near a stagnation-point flow over stretching/shrinking sheet of nanofluids is presented in this paper by considering thermal radiation, Ohmic heating, viscous dissipation and heat source/sink parameter effects. Non-similarity method is adopted for the governing basic equations before they are solved numerically using Runge-Kutta-Fehlberg method using shooting technique. The numerical results are validated by comparing the present results with previously published results. The focus of this paper is to study the effects of some selected governing parameters such as Richardson number, radiation parameter, Schimdt number, Eckert number and magnetic parameter on velocity, temperature and concentration profiles as well as on skin-friction coefficient, local Nusselt number and Sherwood number.

  9. Non-skew-symmetric classical r-matrices, algebraic Bethe ansatz, and Bardeen-Cooper-Schrieffer-type integrable systems

    International Nuclear Information System (INIS)

    Skrypnyk, T.

    2009-01-01

    We construct quantum integrable systems associated with non-skew-symmetric gl(2)-valued classical r-matrices. We find a new explicit multiparametric family of such the non-skew-symmetric classical r-matrices. We consider two classes of examples of the corresponding integrable systems, namely generalized Gaudin systems with and without an external magnetic field. In the case of arbitrary r-matrices diagonal in a standard gl(2)-basis, we calculate the spectrum of the corresponding quantum integrable systems using the algebraic Bethe ansatz. We apply these results to a construction of integrable fermionic models and obtain a wide class of integrable Bardeen-Cooper-Schrieffer (BCS)-type fermionic Hamiltonians containing the pairing and electrostatic interaction terms. We also consider special cases when the corresponding integrable Hamiltonians contain only pairing interaction term and are exact analogs of the 'reduced BCS Hamiltonian' of Richardson

  10. On approximation of non-Newtonian fluid flow by the finite element method

    Science.gov (United States)

    Svácek, Petr

    2008-08-01

    In this paper the problem of numerical approximation of non-Newtonian fluid flow with free surface is considered. Namely, the flow of fresh concrete is addressed. Industrial mixtures often behaves like non-Newtonian fluids exhibiting a yield stress that needs to be overcome for the flow to take place, cf. [R.B. Bird, R.C. Armstrong, O. Hassager, Dynamics of Polymeric Liquids, vol. 1, Fluid Mechanics, Wiley, New York, 1987; R.P. Chhabra, J.F. Richardson, Non-Newtonian Flow in the Process Industries, Butterworth-Heinemann, London, 1999]. The main interest is paid to the mathematical formulation of the problem and to discretization with the aid of finite element method. The described numerical procedure is applied onto the solution of several problems.

  11. Nonmotor Features in Atypical Parkinsonism.

    Science.gov (United States)

    Bhatia, Kailash P; Stamelou, Maria

    2017-01-01

    Atypical parkinsonism (AP) comprises mainly multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD), which are distinct pathological entities, presenting with a wide phenotypic spectrum. The classic syndromes are now called MSA-parkinsonism (MSA-P), MSA-cerebellar type (MSA-C), Richardson's syndrome, and corticobasal syndrome. Nonmotor features in AP have been recognized almost since the initial description of these disorders; however, research has been limited. Autonomic dysfunction is the most prominent nonmotor feature of MSA, but also gastrointestinal symptoms, sleep dysfunction, and pain, can be a feature. In PSP and CBD, the most prominent nonmotor symptoms comprise those deriving from the cognitive/neuropsychiatric domain. Apart from assisting the clinician in the differential diagnosis with Parkinson's disease, nonmotor features in AP have a big impact on quality of life and prognosis of AP and their treatment poses a major challenge for clinicians. © 2017 Elsevier Inc. All rights reserved.

  12. Nuclear Energy Research Initiative (NERI): On-Line Intelligent Self-Diagnostic Monitoring for Next Generation Nuclear Plants - Phase I Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    L. J. Bond; S. R. Doctor; R. W. Gilbert; D. B. Jarrell; F. L. Greitzer; R. J. Meador

    2000-09-01

    OAK-B135 This OSTI ID belongs to an IWO and is being released out of the system. The Program Manager Rebecca Richardson has confirmed that all reports have been received. The objective of this project is to design and demonstrate the operation of the real-time intelligent self-diagnostic and prognostic system for next generation nuclear power plant systems. This new self-diagnostic technology is titled, ''On-Line Intelligent Self-Diagnostic Monitoring System'' (SDMS). This project provides a proof-of-principle technology demonstration for SDMS on a pilot plant scale service water system, where a distributed array of sensors is integrated with active components and passive structures typical of next generation nuclear power reactor and plant systems. This project employs state-of-the-art sensors, instrumentation, and computer processing to improve the monitoring and assessment of the power reactor system and to provide diagnostic and automated prognostics capabilities.

  13. The accountant as triage master: an economist's perspective on voluntary euthanasia and the value of life debate.

    Science.gov (United States)

    Richardson, J

    1987-07-01

    The author, an economist, rebuts the contention that human life cannot and should not be economically evaluated and argues that such evaluations are made implicitly and inconsistently, resulting in a reduction of human welfare. He presents an economic framework for the analysis of costs and benefits in which the focal point, as in most value systems, is the tradeoff between life and quality of life. Therefore, as the quality of life decreases, society's efforts to preserve life should decrease. If the valuation of life includes self evaluation, then there should be less effort to preserve the life of an individual who wishes to die. Richardson concludes that voluntary euthanasia is a limiting case in which society accepts the individual's valuation of life.

  14. Complexity Studies and Security in the Complex World: An Epistemological Framework of Analysis

    Science.gov (United States)

    Mesjasz, Czeslaw

    The impact of systems thinking can be found in numerous security-oriented research, beginning from the early works on international system: Pitrim Sorokin, Quincy Wright, first models of military conflict and war: Frederick Lanchester, Lewis F. Richardson, national and military security (origins of RAND Corporation), through development of game theory-based conflict studies, International Relations, classical security studies of Morton A. Kaplan, Karl W. Deutsch [Mesjasz 1988], and ending with contemporary ideas of broadened concepts of security proposed by the Copenhagen School [Buzan et al 1998]. At present it may be even stated that the new military and non-military threats to contemporary complex society, such as low-intensity conflicts, regional conflicts, terrorism, environmental disturbances, etc. cannot be embraced without ideas taken from modern complex systems studies.

  15. Electron work function of stepped tungsten surfaces

    International Nuclear Information System (INIS)

    Krahl-Urban, B.

    1976-03-01

    The electron work function of tungsten (110) vicinal faces was measured with the aid of thermionic emission, and its dependence on the crystallographic orientation and the surface structure was investigated. The thermionic measurements were evaluated with the aid of the Richardson plot. The real temperature of the emitting tungsten faces was determined with an accuracy of +- 0.5% in the range between 2,200 and 2,800 K. The vicinal faces under investigation have been prepared with an orientation exactness of +- 15'. In the tungsten (110) vicinal faces under investigation, a strong dependence of the temperature coefficient d PHI/dT of the work function on the crystallographic orientation was found. A strong influence of the edge structure as well as of the step density on the temperature coefficient was observed. (orig./HPOE) [de

  16. Experimental investigations on scaled models for the SNR-2 decay heat removal by natural convection

    International Nuclear Information System (INIS)

    Hoffmann, H.; Weinberg, D.; Tschoeke, H.; Frey, H.H.; Pertmer, G.

    1986-01-01

    Scaled water models are used to prove the mode of function of the decay heat removal by natural convection for the SNR-2. The 2D and 3D models were designed to reach the characteristic numbers (Richardson, Peclet) of the reactor. In the experiments on 2D models the position of the immersed cooler (IC) and the power were varied. Temperature fields and velocities were measured. The IC installed as a separate component in the hot plenum resulted in a very complex flow behavior and low temperatures. Integrating the IC in the IHX showed a very simple circulating flow and high temperatures within the hot plenum. With increasing power only slightly rising temperature differences within the core and IC were detected. Recalculations using the COMMIX 1B code gave qualitatively satisfying results. (author)

  17. What is the play of gender? Learning to be "boy" ... Learning to be "girl"

    Directory of Open Access Journals (Sweden)

    Liana Gois Leite

    2016-05-01

    Full Text Available Gender is a social construct, that is, an entirely social creation of ideas about the roles specific to men and to women (BEAVOUIR, 1970. In this context, the present study examined the relationships between different genres and the way they are expressed in "play". The sample had 15 children, seven girls and eight boys, all aged between three and four years, students of a Children's Educational Center in Brasilia, Federal District. Five sessions of Systematic Observation of spontaneous play, a moment where children did not have directed activities, were performed (RICHARDSON, 1999 along with a semi-structured interview with the teacher responsible for the class. From the data analysis, it can be inferred that the formation of groups was not necessarily determined by the composition of the group according to different genres, however, a higher incidence of homogeneous groups was found. The games do not necessarily follow social stereotypes linked to gender.

  18. The history of NATO TNF policy: The role of studies, analysis and exercises conference proceedings

    International Nuclear Information System (INIS)

    Rinne, R.L.

    1994-02-01

    This conference was organized to study and analyze the role of simulation, analysis, modeling, and exercises in the history of NATO policy. The premise was not that the results of past studies will apply to future policy, but rather that understanding what influenced the decision process -- and how -- would be of value. The structure of the conference was built around discussion panels. The panels were augmented by a series of papers and presentations focusing on particular TNF events, issues, studies, or exercises. The conference proceedings consist of three volumes. Volume 1 contains the conference introduction, agenda, biographical sketches of principal participants, and analytical summary of the presentations and panels. This volume contains a short introduction and the papers and presentations from the conference. Volume 3 contains selected papers by Brig. Gen. Robert C. Richardson III (Ret.). Individual papers in this volume were abstracted and indexed for the database

  19. Spectral structure of mesoscale winds over the water

    DEFF Research Database (Denmark)

    Larsén, Xiaoli Guo; Vincent, Claire Louise; Larsen, Søren Ejling

    2013-01-01

    to describe the spectral slope transition as well as the limit for application of the Taylor hypothesis. The stability parameter calculated from point measurements, the bulk Richardson number, is found insufficient to represent the various atmospheric structures that have their own spectral behaviours under...... spectra show universal characteristics, in agreement with the findings in literature, including the energy amplitude and the −5/3 spectral slope in the mesoscale range transitioning to a slope of −3 for synoptic and planetary scales. The integral time-scale of the local weather is found to be useful...... different stability conditions, such as open cells and gravity waves. For stationary conditions, the mesoscale turbulence is found to bear some characteristics of two-dimensional isotropy, including (1) very minor vertical variation of spectra; (2) similar spectral behaviour for the along- and across...

  20. A 3-D Chemistry Transport Model for Titan's Thermosphere

    Science.gov (United States)

    Doege, M. C.; Marsh, D. R.; Brasseur, G. P.; Mueller-Wodarg, I.; Tokano, T.; Newman, C. E.

    2008-12-01

    MOZART-2 (Horowitz et al., 2003) has been adapted to investigate seasonal and diurnal differences in neutral composition in Titan's atmosphere between the surface and 1,200 km altitude. The chemical scheme with 64 solution species and 383 reactions is based on a simplified version of the Lavvas et al. (2008) scheme, without haze production. Wind and temperature fields were taken from the Cologne GCM (Tokano, 2007) or TitanWRF (Richardson et al., 2007) for the troposphere and stratosphere, and from the London TGCM (Mueller-Wodarg, 2000) for the thermosphere. Pronounced hemispheric concentration gradients develop in the thermosphere, and a strong diurnal cycle in composition is found, similar to the findings of Mueller-Wodarg (2003) for methane. Sensitivity experiments with different strengths of thermospheric circulation to account for uncertainty about the wind fields in that region are presented.

  1. Characterization of the host response to the myxosporean parasite, Ceratomyxa shasta (Noble), by histology, scanning electron microscopy, and immunological techniques

    Science.gov (United States)

    Bartholomew, J.L.; Smith, C.E.; Rohovec, J.S.; Fryer, J.L.

    1989-01-01

    The tissue response of Salmo gairdneri Richardson, against the myxosporean parasite. Ceratomyxa shasta (Noble), was investigated using histological techniques, scanning electron microscopy and immunological methods. The progress of infection in C. shasta-susceptible and resistant steelhead and rainbow trout was examined by standard histological techniques and by indirect fluorescent antibody methods using monoclonal antibodies directed against C. shasta antigens. Trophozoite stages were first observed in the posterior intestine and there was indication that resistance was due to the inability of the parasite to penetrate this tissue rather than to an inflammatory response. Examination of a severely infected intestine by scanning electron microscopy showed extensive destruction of the mucosal folds of the posterior intestine. Western blotting and indirect fluorescent antibody techniques were used to investigate the immunological component of the host response. No antibodies specific for C. shasta were detected by either method.

  2. Validity and reliability of the Structured Clinical Interview for Mood Spectrum: Brazilian version (SCIMOODS-VB Validade e confiabilidade da versão brasileira da Entrevista Clínica Estruturada para o Espectro do Humor (SCIMOODS-VB

    Directory of Open Access Journals (Sweden)

    Roberto Ratzke

    2011-03-01

    Full Text Available OBJECTIVE: The aim of this study was to translate the Structured Clinical Interview for Mood Spectrum into Brazilian Portuguese, measuring its reliability, validity, and defining scores for bipolar disorders. METHOD: Questionnaire was translated (into Brazilian Portuguese and back-translated into English. Sample consisted of 47 subjects with bipolar disorder, 47 with major depressive disorder, 18 with schizophrenia and 22 controls. Inter-rater reliability was tested in 20 subjects with bipolar disorder and MDD. Internal consistency was measured using the Kuder Richardson formula. Forward stepwise discriminant analysis was performed. Scores were compared between groups; manic (M, depressive (D and total (T threshold scores were calculated through receiver operating characteristic (ROC curves. RESULTS: Kuder Richardson coefficients were between 0.86 and 0.94. Intraclass correlation coefficient was 0.96 (CI 95 % 0.93-0.97. Subjects with bipolar disorder had higher M and T, and similar D scores, when compared to major depressive disorder (ANOVA, p OBJETIVO: Traduzir e validar para o português a Entrevista Clínica Estruturada para Distúrbios do Humor, mensurando sua validade, confiabilidade, bem como definindo os escores para transtornos bipolares. MÉTODO: A entrevista foi traduzida (para o português e novamente traduzida para o inglês. A amostra incluiu 47 indivíduos com transtornos bipolares, 47 com transtorno depressivo maior, 18 com esquizofrenia e 22 controles. A confiabilidade entre avaliadores foi testada em 20 indivíduos com transtornos bipolares e transtorno depressivo maior. A consistência interna foi mensurada por meio da fórmula de Kuder Richardson. Análise discriminante foi realizada. Escores dos diversos grupos foram comparados; limiares para mania (M, depressão (D e valores totais foram calculados usando curvas de "receiver operating characteristic" (ROC. RESULTADOS: Coeficientes de Kuder Richardson ficaram entre 0,86 e 0

  3. SAPS-Associated Explosive Brightening on the Duskside: A New Type of Onset-Like Disturbance

    Science.gov (United States)

    Henderson, M. G.; Morley, S. K.; Kepko, L. E.

    2018-01-01

    Quasiperiodic energetic particle injections have been observed at geosynchronous orbit on the duskside during a steady magnetospheric convection event. We examine high-resolution auroral imager data and ground magnetometer data associated with the first of these injections and conclude that it was not associated with classical substorm signatures. It is proposed that these injections are caused by the explosive nonlinear growth of a shear flow-ballooning instability in the region where subauroral polarization streams (SAPS) also occur. It is suggested that interchange will occur preferentially in the low-conductivity SAPS region since the magnetic Richardson number is lowest there and the "line-tying" effect will also be least stabilizing there. We propose that the observed particle injection signatures and auroral morphology constitute a new type of SAPS-associated explosive "onset-like" disturbance that can occur during intervals of strong convection.

  4. Error Mitigation for Short-Depth Quantum Circuits

    Science.gov (United States)

    Temme, Kristan; Bravyi, Sergey; Gambetta, Jay M.

    2017-11-01

    Two schemes are presented that mitigate the effect of errors and decoherence in short-depth quantum circuits. The size of the circuits for which these techniques can be applied is limited by the rate at which the errors in the computation are introduced. Near-term applications of early quantum devices, such as quantum simulations, rely on accurate estimates of expectation values to become relevant. Decoherence and gate errors lead to wrong estimates of the expectation values of observables used to evaluate the noisy circuit. The two schemes we discuss are deliberately simple and do not require additional qubit resources, so to be as practically relevant in current experiments as possible. The first method, extrapolation to the zero noise limit, subsequently cancels powers of the noise perturbations by an application of Richardson's deferred approach to the limit. The second method cancels errors by resampling randomized circuits according to a quasiprobability distribution.

  5. The history of NATO TNF policy: The role of studies, analysis and exercises conference proceedings. Volume 1, Introduction and summary

    Energy Technology Data Exchange (ETDEWEB)

    Rinne, R.L. [ed.

    1994-02-01

    This conference was organized to study and analyze the role of simulation, analysis, modeling, and exercises in the history of NATO policy. The premise was not that the results of past studies will apply to future policy, but rather that understanding what influenced the decision process -- and how -- would be of value. The structure of the conference was built around discussion panels. The panels were augmented by a series of papers and presentations focusing on particular TNF events, issues, studies or exercise. The conference proceedings consist of three volumes. This volume, Volume 1, contains the conference introduction, agenda, biographical sketches of principal participants, and analytical summary of the presentations and discussion panels. Volume 2 contains a short introduction and the papers and presentations from the conference. Volume 3 contains selected papers by Brig. Gen. Robert C. Richardson III (Ret.).

  6. Procedure for obtaining visas for Switzerland and France

    CERN Multimedia

    Relations with the Host States Service

    2011-01-01

    SIGNATURE RIGHTS - In accordance with the Status Agreements with CERN, Switzerland and France facilitate the entry of members of the Organization’s personnel on to their territories.  Where relevant, detailed procedures for obtaining visas apply. Within the framework of those procedures, only the following individuals are authorised to initiate the note verbale procedure as well as to sign the Official Invitation Letters and the Conventions d’accueil.  Kirsti ASPOLA (PH – CMO) Oliver BRÜNING (BE – ABP) Michelle CONNOR (PH – AGS) Patrick FASSNACHT (PH-ADO) David FOSTER (IT – DI) Nathalie GRÜB (PH – AGS) Tjitske KEHRER (DG-DI) Tadeusz KURTYKA (DG – PRJ) Cécile NOELS (DG – PRJ) Maria QUINTAS (HR – SPS) Kate RICHARDSON (PH-AGS) Jeanne ROSTANT (PH – AGS) José SALICIO-DIEZ (PH – AGS) Ulla TIHINEN (PH – A...

  7. Procedure for obtaining visas for Switzerland and France - Signature rights

    CERN Multimedia

    2013-01-01

    In accordance with the Status Agreements with CERN, Switzerland and France facilitate the entry of members of the Organization’s personnel on to their territories.  Where relevant, detailed procedures for obtaining visas apply.   Within the framework of those procedures, only the following individuals are authorised to initiate the note verbale procedure as well as to sign the Official Invitation Letters and the Conventions d’accueil. Kirsti ASPOLA (PH – CMO) Oliver BRÜNING (BE – ABP) Michelle CONNOR (PH – AGS) Patrick FASSNACHT (PH-ADO) David FOSTER (IT – DI) Nathalie GRÜB (PH – AGS) Tadeusz KURTYKA (DG – PRJ) Markus NORDBERG (PH – ADO) Cécile NOELS (DG – PRJ) Maria QUINTAS (HR – SPS) Kate RICHARDSON (PH-AGS) Jeanne ROSTANT (PH – AGS) José SALICIO-DIEZ (PH – AGS) Ulla TIHINEN (PH – AGS) Emmanuel...

  8. Procedure for obtaining visas for Switzerland and France Signature rights

    CERN Multimedia

    DG Unit

    2012-01-01

    In accordance with the Status Agreements with CERN, Switzerland and France facilitate the entry of members of the Organization’s personnel on to their territories.  Where relevant, detailed procedures for obtaining visas apply. Within the framework of those procedures, only the following individuals are authorised to initiate the note verbale procedure as well as to sign the Official Invitation Letters and the Conventions d’accueil. Kirsti ASPOLA (PH – CMO) Oliver BRÜNING (BE – ABP) Michelle CONNOR (PH – AGS) Patrick FASSNACHT (PH-ADO) David FOSTER (IT – DI) Nathalie GRÜB (PH – AGS) Tjitske KEHRER (DG-DI) Tadeusz KURTYKA (DG – PRJ) Markus NORDBERG (PH – ADO) Cécile NOELS (DG – PRJ) Maria QUINTAS (HR – SPS) Kate RICHARDSON (PH-AGS) Jeanne ROSTANT (PH – AGS) José SALICIO-DIEZ (PH – AGS) Ulla TIHINEN (PH – AG...

  9. Correlation functions for the distribution coefficients of U(IV) and Pu(III) ions between aqueous nitric acid and 30% TBP in an aliphatic diluent

    Energy Technology Data Exchange (ETDEWEB)

    Geldard, J.F.; Beyerlein, A.L.; Phillips, L.

    1985-09-01

    Distribution coefficient correlations for U(IV) and Pu(III) are obtained in terms of a modified form of the total nitrate ion salting strength that was successfully used to obtain distribution coefficient correlations for U(VI) and Pu(IV) in the earlier work of G.L. Richardson. The modification of salting strength was needed to account for the fact that the U(IV) distribution coefficients measured under conditions where U(VI) is present consistently fall below those obtained when it is absent. The correlations were incorporated into the mixer-settler computer model PUBG, and in the simulation of a 20-stage 1B partitioning contactor, calculated product stream concentrations were in excellent agreement with experiment. Earlier mixer-settler computer models, which failed to account for U(IV) distribution coefficients, predicted that U(IV) remained in the aqueous product stream, which is contrary to the experimental measurements.

  10. A Short History of the Theory and Experimental Discovery of Superfluidity in 3He

    Science.gov (United States)

    Brinkman, W. F.

    I discuss the development of the theory and experiments on superfluid 3He. After the discovery of superfluidity in 3He by Osheroff, Richardson and Lee, Phil Anderson quickly recruited Doug Osheroff to come to Bell Labs and set up a dilution fridge to continue his experiments. One of the mysteries at that time was how the high-temperature A-phase, which has a gapless excitation spectrum, could be stabilized relative to the fully gapped, lower temperature B-phase. I explain how Phil Anderson and I developed the spin fluctuation theory of the A-phase of superfluid 3He which accounted for its stability, leading to the Anderson-Brinkman-Morel (ABM) theory of the superfluid A-phase...

  11. Turbulent transport of passive scalar behind line sources in an unstably stratified open channel flow

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chun-Ho [The Hong Kong Polytechnic University, Kowloon (Hong Kong). Department of Building and Real Estate; Leung, Dennis Y.C. [The University of Hong Kong (Hong Kong). Department of Mechanical Engineering

    2006-11-15

    This study employs a direct numerical simulation (DNS) technique to study the flow, turbulence structure, and passive scalar plume transport behind line sources in an unstably stratified open channel flow. The scalar transport behaviors for five emission heights (z{sub s}=0, 0.25H, 0.5H, 0.75H, and H, where H is the channel height) at a Reynolds number of 3000, a Prandtl number and a Schmidt number of 0.72, and a Richardson number of -0.2 are investigated. The vertically meandering mean plume heights and dispersion coefficients calculated by the current DNS model agree well with laboratory results and field measurements in literature. It is found that the plume meandering is due to the movement of the positive and negative vertical turbulent scalar fluxes above and below the mean plume heights, respectively. These findings help explaining the plume meandering mechanism in the unstably stratified atmospheric boundary layer. (author)

  12. Surface shear stress dependence of gas transfer velocity parameterizations using DNS

    Science.gov (United States)

    Fredriksson, S. T.; Arneborg, L.; Nilsson, H.; Handler, R. A.

    2016-10-01

    Air-water gas-exchange is studied in direct numerical simulations (DNS) of free-surface flows driven by natural convection and weak winds. The wind is modeled as a constant surface-shear-stress and the gas-transfer is modeled via a passive scalar. The simulations are characterized via a Richardson number Ri=Bν/u*4 where B, ν, and u* are the buoyancy flux, kinematic viscosity, and friction velocity respectively. The simulations comprise 0Ric or kg=AShearu*Sc-n, Ri

  13. Chaotic evolution of arms races

    Science.gov (United States)

    Tomochi, Masaki; Kono, Mitsuo

    1998-12-01

    A new set of model equations is proposed to describe the evolution of the arms race, by extending Richardson's model with special emphases that (1) power dependent defensive reaction or historical enmity could be a motive force to promote armaments, (2) a deterrent would suppress the growth of armaments, and (3) the defense reaction of one nation against the other nation depends nonlinearly on the difference in armaments between two. The set of equations is numerically solved to exhibit stationary, periodic, and chaotic behavior depending on the combinations of parameters involved. The chaotic evolution is realized when the economic situation of each country involved in the arms race is quite different, which is often observed in the real world.

  14. University Students with Dyslexia: A Qualitative Exploratory Study of Learning Practices, Challenges and Strategies.

    Science.gov (United States)

    MacCullagh, Lois; Bosanquet, Agnes; Badcock, Nicholas A

    2017-02-01

    People with dyslexia are vastly under-represented in universities (Katusic et al., , Richardson & Wydell, ; Stampoltzis & Polychronopoulou, ). This situation is of concern for modern societies that value social justice. This study was designed to explore learning experiences of university students with dyslexia and factors that could contribute to their success. Thirteen students with dyslexia and 20 non-dyslexic peers were interviewed about their university learning experiences using a semi-structured qualitative approach. Students with dyslexia described engaging in learning activities intensively, frequently and strategically. They reported challenges and strengths relating to study skills, lectures, assessments, technology and support services. They also described helpful strategies including self-directed adaptive techniques, provisions from lecturers and assistance from the university. These findings suggest that students with dyslexia experience broad challenges at university, but helpful strategies may be available. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  15. Transient mixed convection in a cavity. Comparison between water and sodium

    International Nuclear Information System (INIS)

    Garnier, J.

    1983-01-01

    The basic problem studied is the interaction between a vortex and a thermal stratification. The experiments are done in a parallelepipedic cavity which bottom communicates with a rectangular channel. A forced flow in this channel induces a recirculating flow in the cavity. The transient condition is a decrease (step wise or slope) of the inlet temperature at a constant flowrate. This problem is studied with two different approaches: experiments in water or in sodium. In the sodium experiments, the dimension of the cavity ensures large values of the Peclet number (about 10 4 ) and a wide range of values for the Richardson number (from 0.1 to 3). With these experiment, all the regimes of mixed convection, from forced convection to complete stratification can be covered. These results are compared with the other approach using a water model. This comparison is very helpful for studies on the thermalhydraulic behavior of Liquid Metal Fast Breeder Reactors. (author)

  16. Radioactivity induced by neutrons: Enrico Fermi and a thermodynamic approach to radiative capture

    Science.gov (United States)

    De Gregorio, Alberto

    2006-07-01

    When Fermi learned that slow neutrons are much more effective than fast ones in inducing radioactivity, he explained this phenomenon by mentioning the well-known scattering cross section between neutrons and protons. At this early stage, he did not refer to the capture cross section by target nuclei. At the same time a thermodynamic approach to neutron-proton capture was being discussed by physicists: neutron capture was interpretated as the reverse of deuteron photodissociation and detailed balance among neutrons, protons, deuterons, and radiation was invoked. This thermodynamic approach might underlie Fermi's early explanation of the great efficiency of slow neutrons. Fermi repeatedly used a thermodynamic approach that had been used in describing some of the physical properties of conductors by Richardson and had been influential in Fermi's youth.

  17. Non-equilibrium thermionic electron emission for metals at high temperatures

    Science.gov (United States)

    Domenech-Garret, J. L.; Tierno, S. P.; Conde, L.

    2015-08-01

    Stationary thermionic electron emission currents from heated metals are compared against an analytical expression derived using a non-equilibrium quantum kappa energy distribution for the electrons. The latter depends on the temperature decreasing parameter κ ( T ) , which decreases with increasing temperature and can be estimated from raw experimental data and characterizes the departure of the electron energy spectrum from equilibrium Fermi-Dirac statistics. The calculations accurately predict the measured thermionic emission currents for both high and moderate temperature ranges. The Richardson-Dushman law governs electron emission for large values of kappa or equivalently, moderate metal temperatures. The high energy tail in the electron energy distribution function that develops at higher temperatures or lower kappa values increases the emission currents well over the predictions of the classical expression. This also permits the quantitative estimation of the departure of the metal electrons from the equilibrium Fermi-Dirac statistics.

  18. The Impact of Mexican Revolution: The Richard­son Building Company in the Valle del Yaqui

    Directory of Open Access Journals (Sweden)

    Atsumi Okada

    2000-07-01

    Full Text Available This essay examines the  impact of the Mexican Revolution in business activities by focusing on a study of the Compañía Con­structora  Richardson,  an  enterprise  which was  to  provide hidraulic infrastructure in the Yaqui Valley during the  revolu­tion. The company faced numerous obstacles caused by the rev­olution: conflicts with yaquis in the Yaqui Valley itself, and insti­tutional changes of federal and local governments, including the loss of its concession because of disagreement with the gov­ernment with regard to the new fiscal system. This study shows that, while presidents expressed different views about private en­terprises involved in hidraulic construction, public administra­tive organizations gradually consolidated coherent policies with regard to water management and water resources.

  19. Conocimientos sobre VIH/SIDA en adolescentes embarazadas

    Directory of Open Access Journals (Sweden)

    Blanca Flor Fernández

    2014-11-01

    Full Text Available This work has as purpose to identify the level of knowledge about signs and symptoms that presents a patient with HIV/AIDS, in pregnant adolescents of 14 – 19 years old, this study was conducted in with population attending seven Health Centers of Public Institution and three units of family medicine social security. The instrument was applied “Survey for Pregnant”, elaborated based on the objectives and population chosen, and validated with KR20 of Richardson 0.95 reliability. The work was supported in quantitative methodology with descriptive statistics. The observed results were, 50(35.5% with average knowledge with secondary education, 40(28.3% with midlle and 4(2.8% presented low knowledge with primary and secondary and the high level was absent. In relation to knowledge of signs and symptoms, only 58.44% correctly identified.

  20. New deconvolution method for microscopic images based on the continuous Gaussian radial basis function interpolation model.

    Science.gov (United States)

    Chen, Zhaoxue; Chen, Hao

    2014-01-01

    A deconvolution method based on the Gaussian radial basis function (GRBF) interpolation is proposed. Both the original image and Gaussian point spread function are expressed as the same continuous GRBF model, thus image degradation is simplified as convolution of two continuous Gaussian functions, and image deconvolution is converted to calculate the weighted coefficients of two-dimensional control points. Compared with Wiener filter and Lucy-Richardson algorithm, the GRBF method has an obvious advantage in the quality of restored images. In order to overcome such a defect of long-time computing, the method of graphic processing unit multithreading or increasing space interval of control points is adopted, respectively, to speed up the implementation of GRBF method. The experiments show that based on the continuous GRBF model, the image deconvolution can be efficiently implemented by the method, which also has a considerable reference value for the study of three-dimensional microscopic image deconvolution.

  1. Frederick Law Olmsted y el "Emerald Necklace" de Boston

    Directory of Open Access Journals (Sweden)

    Ricardo Austrich

    2003-09-01

    Full Text Available En 1879, Frederick Law Olmsted, el creador del Central Park en Nueva York, Prospect Park en Brooklyn, inventor de la profesión de paisajismo (Landscape Architecture en los EE.UU., arriba a Boston agotado y exhausto. Acaba de renunciar el cargo de paisajista de Central Park, sintiéndose defraudado por las intrigas políticas de la comisión de parques de Nueva York, viajaba a Boston a descansar y pasar un rato con sus amigos en las cercanías de Boston, en Cambridge y Brookline. Su gran amigo, Henry Hobson Richardson, el reconocido arquitecto de la época, vivía y trabajaba en Brookline, y sirve como su anfitrión, tanto como sus amigos en Cambridge.

  2. Nuclear Energy Research Initiative (NERI): On-Line Intelligent Self-Diagnostic Monitoring for Next Generation Nuclear Plants - Phase I Annual Report

    International Nuclear Information System (INIS)

    Bond, L.G.; Doctor, S.R.; Gilbert, R.W.; Jarrell, D.B.; Greitzer, F.L.; Meador, R.J.

    2000-01-01

    OAK-B135 This OSTI ID belongs to an IWO and is being released out of the system. The Program Manager Rebecca Richardson has confirmed that all reports have been received. The objective of this project is to design and demonstrate the operation of the real-time intelligent self-diagnostic and prognostic system for next generation nuclear power plant systems. This new self-diagnostic technology is titled, ''On-Line Intelligent Self-Diagnostic Monitoring System'' (SDMS). This project provides a proof-of-principle technology demonstration for SDMS on a pilot plant scale service water system, where a distributed array of sensors is integrated with active components and passive structures typical of next generation nuclear power reactor and plant systems. This project employs state-of-the-art sensors, instrumentation, and computer processing to improve the monitoring and assessment of the power reactor system and to provide diagnostic and automated prognostics capabilities

  3. Gas to liquid to solid transition in halogen hot atom chemistry. II. Systematics of bromine reactions activated by radiative neutron capture and isomeric transition with halomethanes

    International Nuclear Information System (INIS)

    Berg, M.E.; Grauer, W.M.; Helton, R.W.; Rack, E.P.

    1975-01-01

    Bromine reactions activated by 79 Br(n,γ) 80 Br, 81 Br(n,γ)/sup 82m/Br + 82 Br, and /sup 82m/Br(I.T.) 82 Br nuclear transformations were studied in halomethanes as functions of mole fraction of Br 2 , phase, density, and intermolecular distance. Gas phase systematics coupled with the density and mole fraction of Br 2 studies demonstrate the existence of systematic trends in the condensed phases as evidenced by the Richardson--Wolfgang effect. A definitive difference due to activation that is independent of system and suggests the importance of caging at higher densities is shown by the variation of total and individual organic product yields with density. The study of total organic product yield vs. intermolecular distance provides both a means of separating cage and molecular reactions and suggests the importance of molecular properties in the caging event. (U.S.)

  4. Correlation functions for the distribution coefficients of U(IV) and Pu(III) ions between aqueous nitric acid and 30% TBP in an aliphatic diluent

    International Nuclear Information System (INIS)

    Geldard, J.F.; Beyerlein, A.L.; Phillips, L.

    1985-01-01

    Distribution coefficient correlations for U(IV) and Pu(III) are obtained in terms of a modified form of the total nitrate ion salting strength that was successfully used to obtain distribution coefficient correlations for U(VI) and Pu(IV) in the earlier work of G.L. Richardson. The modification of salting strength was needed to account for the fact that the U(IV) distribution coefficients measured under conditions where U(VI) is present consistently fall below those obtained when it is absent. The correlations were incorporated into the mixer-settler computer model PUBG, and in the simulation of a 20-stage 1B partitioning contactor, calculated product stream concentrations were in excellent agreement with experiment. Earlier mixer-settler computer models, which failed to account for U(IV) distribution coefficients, predicted that U(IV) remained in the aqueous product stream, which is contrary to the experimental measurements

  5. New doped tungsten cathodes. Applications to power grid tubes

    International Nuclear Information System (INIS)

    Cachard, J. de; Cadoret, K; Martinez, L.; Veillet, D.; Millot, F.

    2001-01-01

    Thermionic emission behavior of tungsten/tungsten carbide modified with rare earth (La, Ce, Y) oxides is examined on account of suitability to deliver important current densities in a thermo-emissive set up and for long lifetime. Work functions of potential cathodes have been determined from Richardson plots for La 2 O 3 doped tungsten and for tungsten covered with variable compositions rare earth tungstates. The role of platinum layers covering the cathode was also examined. Given all cathodes containing mainly lanthanum oxides were good emitters, emphasis was put on service lifetime. Comparisons of lifetime in tungsten doped with rare earth oxides and with rare earth tungstates show that microstructure of the operating cathodes may play the major role in the research of very long lifetime cathodes. Based on these results, tests still running show lifetime compatible with power grid tubes applications. (author)

  6. Milestones in the Development of Iterative Solution Methods

    Directory of Open Access Journals (Sweden)

    Owe Axelsson

    2010-01-01

    Full Text Available Iterative solution methods to solve linear systems of equations were originally formulated as basic iteration methods of defect-correction type, commonly referred to as Richardson's iteration method. These methods developed further into various versions of splitting methods, including the successive overrelaxation (SOR method. Later, immensely important developments included convergence acceleration methods, such as the Chebyshev and conjugate gradient iteration methods and preconditioning methods of various forms. A major strive has been to find methods with a total computational complexity of optimal order, that is, proportional to the degrees of freedom involved in the equation. Methods that have turned out to have been particularly important for the further developments of linear equation solvers are surveyed. Some of them are presented in greater detail.

  7. Modeling the behavior of optical elements in radiation environments

    International Nuclear Information System (INIS)

    Barlow, T.A.; Rhoades, C.E. Jr.; Merker, M.; Triplett, J.R.

    1986-01-01

    Calculation of heating caused by the deposition of x-rays in thin film optical elements is complicated because the mean free path of photo and autoionization electrons is comparable to the thin film thickness and thus the electron deposition cannot be considered local. This paper describes the modeling in a 1-D code of: (a) x-ray deposition and transport; (b) electron production, deposition and transport; and (c) thermal conduction and transport. X-ray transport is handled by multigroup discrete ordinates, electron transport is done by the method of characteristics, applied to the two term spherical harmonics expansion approximation (P1) to the Spencer-Lewis transport equation, and thermal transport is computed by a simple Richardson extrapolation of a backward Euler solution to the heat conduction equations. Results of a few test cases are presented. 8 refs., 26 figs., 2 tabs

  8. Foliations dynamics, geometry and topology

    CERN Document Server

    Nicolau, Marcel

    2014-01-01

    This book is an introduction to several active research topics in Foliation Theory and its connections with other areas. It contains expository lectures showing the diversity of ideas and methods arising and used in the study of foliations. The lectures by A. El Kacimi Alaoui offer an introduction to Foliation Theory, with emphasis on examples and transverse structures. S. Hurder's lectures apply ideas from smooth dynamical systems to develop useful concepts in the study of foliations, like limit sets and cycles for leaves, leafwise geodesic flow, transverse exponents, stable manifolds, Pesin Theory, and hyperbolic, parabolic, and elliptic types of foliations, all of them illustrated with examples. The lectures by M. Asaoka are devoted to the computation of the leafwise cohomology of orbit foliations given by locally free actions of certain Lie groups, and its application to the description of the deformation of those actions. In the lectures by K. Richardson, he studies the geometric and analytic properties ...

  9. Bethe ansatz and ordinary differential equation correspondence for degenerate Gaudin models

    Science.gov (United States)

    El Araby, Omar; Gritsev, Vladimir; Faribault, Alexandre

    2012-03-01

    In this work, we generalize the numerical approach to Gaudin models developed earlier by us [Faribault, El Araby, Sträter, and Gritsev, Phys. Rev. BPRBMDO1098-012110.1103/PhysRevB.83.235124 83, 235124 (2011)] to degenerate systems, showing that their treatment is surprisingly convenient from a numerical point of view. In fact, high degeneracies not only reduce the number of relevant states in the Hilbert space by a non-negligible fraction, they also allow us to write the relevant equations in the form of sparse matrix equations. Moreover, we introduce an inversion method based on a basis of barycentric polynomials that leads to a more stable and efficient root extraction, which most importantly avoids the necessity of working with arbitrary precision. As an example, we show the results of our procedure applied to the Richardson model on a square lattice.

  10. Marine boundary layer and turbulent fluxes over the Baltic Sea: Measurements and modelling

    DEFF Research Database (Denmark)

    Gryning, Sven-Erik; Batchvarova, E.

    2002-01-01

    Two weeks of measurements of the boundary-layer height over a small island (Christianso) in the Baltic Sea are discussed. The meteorological conditions are characterised by positive heat flux over the sea. The boundary-layer height was simulated with two models, a simple applied high-resolution (2...... km x 2 km) model, and the operational numerical weather prediction model HIRLAM (grid resolution of 22.5 km x 22.5 km). For southwesterly winds it was found that a relatively large island (Bornholm) lying 20-km upwind of the measuring site influences the boundary-layer height. In this situation...... the high-resolution simple applied model reproduces the characteristics of the boundary-layer height over the measuring site. Richardson-number based methods using data from simulations with the HIRLAM model fail, most likely because the island and the water fetch to the measuring site are about the size...

  11. Neighborhood social capital and adult health: an empirical test of a Bourdieu-based model.

    Science.gov (United States)

    Carpiano, Richard M

    2007-09-01

    Drawing upon Bourdieu's [1986. The forms of capital. In: Richardson, J.G. (Ed.), Handbook of Theory and Research for the Sociology of Education. Greenwood, New York, pp. 241-258.] social capital theory, I test a conceptual model of neighborhood conditions and social capital - considering relationships between neighborhood social capital forms (social support, social leverage, informal social control, and neighborhood organization participation) and adult health behaviors (smoking, binge drinking) and perceived health, as well as interactions between neighborhood social capital and individuals' access to that social capital. Analyzing Los Angeles Family and Neighborhood Survey data linked with tract level census data, results suggest that specific social capital forms were directly associated with both positive and negative health outcomes. Additionally, residents' neighborhood attachment moderated relationships between various social capital forms and health. Future studies should consider social capital resources and the role of differential access to such resources for promoting or compromising health.

  12. Progressive Supranuclear Palsy: an Update.

    Science.gov (United States)

    Armstrong, Melissa J

    2018-02-17

    Progressive supranuclear palsy (PSP) is a 4R tau neuropathologic entity. While historically defined by the presence of a vertical supranuclear gaze palsy and falls in the first symptomatic year, clinicopathologic studies identify alternate presenting phenotypes. This article reviews the new PSP diagnostic criteria, diagnostic approaches, and treatment strategies. The 2017 International Parkinson and Movement Disorder Society PSP criteria outline 14 core clinical features and 4 clinical clues that combine to diagnose one of eight PSP phenotypes with probable, possible, or suggestive certainty. Evidence supports the use of select imaging approaches in the classic PSP-Richardson syndrome phenotype. Recent trials of putative disease-modifying agents showed no benefit. The new PSP diagnostic criteria incorporating the range of presenting phenotypes have important implications for diagnosis and research. More work is needed to understand how diagnostic evaluations inform phenotype assessment and identify expected progression. Current treatment is symptomatic, but tau-based therapeutics are in active clinical trials.

  13. Radioactive contamination of the significant fish species in fish-ponds and in natural waters with particular respect to the accumulation of Sr-90 Pt. 2

    International Nuclear Information System (INIS)

    Kantor, D.; Szentjobi, O.

    1977-01-01

    The radioactive contamination of omnivorous fish species (Cyprinus carpio, Hypophtalmictys nobilis Richardson), of herbivorous fish species (Hypophtalmictys molitrix Valenciennes) and carnivorous fish species (Silurus glanis L., Esox Lucius L.) has been investigated. Orientative data have been obtained by analyzing samples originating from various sites. Though differences appeared between the analyzed samples, no incorporations of outstanding nature have been observed. In accordance with experiences described in literature, the isotope Sr-90 is accumulated in an increased degree in the skeleton of fish living in ponds. This is valid in all cases when the vital processes are regulated artificially by fishery methods. A particularly important factor is that the individual fish living in ponds are 2-3 or at most 4 years of age i.e. from the aspect of their ontogenesis their organism is in a strongly build-up phase. Sr-90 proved to be accumulated in a relatively greater amount in the organisms of herbivorous fish. (P.J.)

  14. Dynamical passage to approximate equilibrium shapes for spinning, gravitating rubble asteroids

    Science.gov (United States)

    Sharma, Ishan; Jenkins, James T.; Burns, Joseph A.

    2009-03-01

    Many asteroids are thought to be particle aggregates held together principally by self-gravity. Here we study — for static and dynamical situations — the equilibrium shapes of spinning asteroids that are permitted for rubble piles. As in the case of spinning fluid masses, not all shapes are compatible with a granular rheology. We take the asteroid to always be an ellipsoid with an interior modeled as a rigid-plastic, cohesion-less material with a Drucker-Prager yield criterion. Using an approximate volume-averaged procedure, based on the classical method of moments, we investigate the dynamical process by which such objects may achieve equilibrium. We first collapse our dynamical approach to its statical limit to derive regions in spin-shape parameter space that allow equilibrium solutions to exist. At present, only a graphical illustration of these solutions for a prolate ellipsoid following the Drucker-Prager failure law is available [Sharma, I., Jenkins, J.T., Burns, J.A., 2005a. Bull. Am. Astron. Soc. 37, 643; Sharma, I., Jenkins, J.T., Burns, J.A., 2005b. Equilibrium shapes of ellipsoidal soil asteroids. In: García-Rojo, R., Hermann, H.J., McNamara, S. (Eds.), Proceedings of the 5th International Conference on Micromechanics of Granular Media, vol. 1. A.A. Balkema, UK; Holsapple, K.A., 2007. Icarus 187, 500-509]. Here, we obtain the equilibrium landscapes for general triaxial ellipsoids, as well as provide the requisite governing formulae. In addition, we demonstrate that it may be possible to better interpret the results of Richardson et al. [Richardson, D.C., Elankumaran, P., Sanderson, R.E., 2005. Icarus 173, 349-361] within the context of a Drucker-Prager material. The graphical result for prolate ellipsoids in the static limit is the same as those of Holsapple [Holsapple, K.A., 2007. Icarus 187, 500-509] because, when worked out, his final equations will match ours. This is because, though the formalisms to reach these expressions differ, in statics

  15. Review and intercomparison of operational methods for the determination of the mixing height

    DEFF Research Database (Denmark)

    Seibert, P.; Beyrich, F.; Gryning, Sven-Erik

    2002-01-01

    The height of the atmospheric boundary layer (ABL) or the mixing height (MH) is a fundamental parameter characterising the structure of the lower troposphere. Two basic possibilities for the practical determination of the MH are its derivation from profile data (measurements or numerical model...... output) and its parameterisation using simple equations or models (which only need a few measured input values). Different methods suggested in the literature are reviewed in this paper. The most important methods have been tested on data sets from three different sites in Europe (Cabauw—NL, Payerne......—CH, Melpitz—D). Parcel and Richardson number methods applied to radiosonde profiles and the analysis of sodar and wind profiler data have been investigated. Modules for MH determination implemented in five currently used meteorological preprocessors for dispersion models have been tested, too. Parcel methods...

  16. Review and intercomparison of operational methods for the determination of the mixing height

    DEFF Research Database (Denmark)

    Seibert, P.; Beyrich, F.; Gryning, Sven-Erik

    2000-01-01

    The height of the atmospheric boundary layer (ABL) or the mixing height (MH) is a fundamental parameter characterising the structure of the lower troposphere. Two basic possibilities for the practical determination of the MH are its derivation from profile data (measurements or numerical model...... output) and its parameterisation using simple equations or models (which only need a few measured input values). Different methods suggested in the literature are reviewed in this paper. The most important methods have been tested on data sets from three different sites in Europe (Cabauw - NL, Payerne...... - CH, Melpitz - D). Parcel and Richardson number methods applied to radiosonde profiles and the analysis of sodar and wind profiler data have been investigated. Modules for MH determination implemented in five currently used meteorological preprocessors for dispersion models have been tested, too...

  17. QCD-based relativistic Hartree-Fock calculations for identical quarks

    International Nuclear Information System (INIS)

    Dey, J.; Dey, M.; Le Tourneux, J.

    1985-12-01

    As was first pointed out by Witten, large number of colours (Nsub(c)) leads to a simplification in the theory of baryon masses in that the quarks may be assumed to move in a mean field which can be found self-consistently. The interquark potential in such a description can be borrowed from the meson sector phenomenology in the absence of an accurate evaluation of it from large Nsub(c) quantum chromodynamics (QCD). We have carried out this program with such a potential due to Richardson, used often by workers in the meson sector. This potential has the advantage of incorporating the two main features of QCD, namely confinement and asymptotic freedom. In view of the small number of parameters involved, the results agree surprisingly well with experiment for the case of three identical quarks. (author)

  18. Effects of various potential models for fourth SM family (Ψ4) quarkonia production at e''+ e''- colliders

    International Nuclear Information System (INIS)

    Ciftci, R.; Sultansoy, S.

    2002-01-01

    In the framework of democratic mass matrix (DMM) approach the lower limit on the fourth standard model (SM) family quarkonia mass is 640 GeV, so future e+e- colliders (TESLA, JLC/NLC and CLIC) with a good beam resolution will give opportunity to investigate properties of vector (ψ 4 ) quarkonia. We estimate ψ 4 production cross-sections by using various potential models (Coulomb, Martin, Cornell and Richardson). Signatures of the process e''+e''-→ψ 4 are discussed taking into account any decay modes of y4 quarkonia. Especially ψ 4 →and ψ 4 →γH channels will open new window for investigation of Higgs boson properties

  19. PerformAge

    DEFF Research Database (Denmark)

    Fristrup, Tine

    2012-01-01

    are constituted as experts on aging. In the humanistic model of aging, the aging self becomes the expert on the process of becoming of age. Thi sconflicting aspect of the discursive battlefield on aging will be elaborated in the framework of PerformAge and understood as a temporal and spatial theorising of aging......: the poetics of aging. Making the lived experience the centrepiece of this paper, poetic representations of aging lives (Laurel Richardson, 1991, 1992) will articulate subjectively felt experiences in social encounters between people performing age. In writing the social (Dorothy E. Smith, 1999) encounters, I...... as a researcher perform age in the process of figuring the possible age performativities as subject positioning performativity (Judith Butler, 1995) in the social encounters and textualized in poetic representations. Inspired by the work on Reifungsromane (Barbara Frey Waxman, 1990), I do not want to paint...

  20. Nobel drawings

    CERN Multimedia

    Michel Blanc

    2009-01-01

    1. The Universe in One Drawing (G. Smoot Physics 2006) 2. Superfluid Properties (R. Richardson Physics 1996) 3. The Asymptotic Freedom of the Quark (David Gross, Physics 2004) 4. Understanding Superfluidity (Anthony Legget, Physics 2003) 5. Taming Infinities (G. 't Hooft, Physics 1999) 6. Homo Diagrammaticus (M. Veltman, Physics 1999) 7. A Tale Of Two Liquids (D. Osheroff, Physics 1996) 8. Wire Proliferation (G. Charpak, Physics 1992) 9. High Temperature Superconductivity (G. Bednorz, Physics 1987) 10. Atomic Cuisine (courtesy of C. Rubbia, Physics 1984) 11. Colliding Charm (S. Ting, Physics 1976) 12. The Bubble Chamber ( D. Glaser, Physics 1960) 13. The Narrow Resonance of the J-Psi (B. Richter, Physics 1976) 14. Stochastic Cooling (S. Van der Meer, Physics 1984) 15. The Good Anomaly (J Steinberger, Physics 1988) 16. Quark Somewhere on the White Paper (R. Taylor, Physics 1990) 17. The Tau of Particle Physics (M. Perl, 1995) 18. NMR Spectroscopy (K. Wuethrich, Chemistry 2002) 19. Coherent States (R....

  1. Fourier analysis of cell-wise Block-Jacobi splitting in two-dimensional geometry

    International Nuclear Information System (INIS)

    Rosa, M.; Warsa, J. S.; Kelley, T. M.

    2009-01-01

    A Fourier analysis is conducted in two-dimensional (2D) geometry for the discrete ordinates (S N ) approximation of the neutron transport problem solved with Richardson iteration (Source Iteration) using the cell-wise Block-Jacobi (BJ) algorithm. The results of the Fourier analysis show that convergence of cell-wise BJ can degrade, leading to a spectral radius equal to 1, in problems containing optically thin cells. For problems containing cells that are optically thick, instead, the spectral radius tends to 0. Hence, in the optically thick-cell regime, cell-wise BJ is rapidly convergent even for problems that are scattering dominated, with a scattering ratio c close to 1. (authors)

  2. Interactions between waves, sediment, and turbulence on a shallow estuarine mudflat

    Science.gov (United States)

    MacVean, Lissa J.; Lacy, Jessica R.

    2014-01-01

    Measurements were collected on a shallow estuarine mudflat in northern San Francisco Bay to examine the physical processes controlling waves, turbulence, sediment resuspension, and their interactions. Tides alone forced weak to moderate currents of 10–30 cm s-1 in depths of 0–3 m, and maintained a background suspension of 30–50 mg L21 of fine sediment. In the presence of wind waves, bottom orbital velocities spanned 20–30 cm s-1, suspended-sediment concentrations (SSC) at 15 and 30 cm above the bed (cmab) increased by 1–2 orders of magnitude, and vertical gradients in SSC were strong enough to produce turbulence-limiting stratification, with gradient Richardson numbers exceeding 0.25. Simultaneously, turbulent

  3. Prediction of SEP Peak Proton Intensity Based on CME Speed, Direction and Observations of Associated Solar Phenomena

    Science.gov (United States)

    Richardson, I. G.; Mays, M. L.; Thompson, B. J.; Kwon, R.; Frechette, B. P.

    2017-12-01

    We assess whether a formula obtained by Richardson et al. (Solar Phys., 289, 3059, 2014; DOI 10.1007/s11207-014-0524-8) relating the intensity of 14-24 MeV protons in a solar energetic particle event at 1 AU to the solar event location and the speed of the associated coronal mass ejection (CME), may be used to "predict" the intensity of a solar energetic particle event. Starting with a subset of several hundred CMEs in the CCMC/SWRC DONKI real-time database (http://kauai.ccmc.gsfc.nasa.gov/DONKI/) selected without consideration of whether they were associated with SEP events, we first use the CME speed and direction to predict the proton intensity at Earth or the STEREO spacecraft using this formula. Since most of these CMEs were not in fact associated with SEP events, many "false alarms" result. We then examine whether considering other phenomena which may accompany the CMEs, such as the X-ray flare intensity and the properties of type II and type III radio emissions, may help to reduce the false alarm rate. We also use CME parameters calculated from an ellipsoidal shell fit to multi-spacecraft CME shock observations for a smaller number of events to predict the SEP intensity. We calculate skill scores for each case and assess whether the Richardson et al. (2014) formula, using additional observations to reduce the false alarm rate, has any potential as a SEP prediction tool, assuming that the required observations could be acquired sufficiently rapidly following the onset of the related solar event/CME.

  4. High-temperature Schottky diode characteristics of bulk ZnO

    Energy Technology Data Exchange (ETDEWEB)

    Guer, Emre; Tuezemen, S; Kilic, Bayram; Coskun, C [Department of Physics, Faculty of Arts and Sciences, Atatuerk University, 25240 Erzurum (Turkey)

    2007-05-16

    Current-voltage (I-V) measurements of Ag/n-ZnO have been carried out at temperatures of 200-500 K in order to understand the temperature dependence of the diode characteristics. Forward-bias I-V analysis results in a Schottky barrier height of 0.82 eV and an ideality factor of 1.55 at room temperature. The barrier height of 0.74 eV and Richardson constant of 0.248 A K{sup -2} cm{sup -2} were also calculated from the Richardson plot, which shows nearly linear characteristics in the temperature range 240-440 K. From the nk{sub b}T/q versus k{sub b}T/q graph, where n is ideality factor, k{sub b} the Boltzmann constant, T the temperature and q the electronic charge we deduce that thermionic field emission (TFE) is dominant in the charge transport mechanism. At higher sample temperatures (>440 K), a trap-assisted tunnelling mechanism is proposed due to the existence of a deep donor situated at E{sub c}-0.62 eV with 3.3 x 10{sup -15} cm{sup 2} capture cross section observed by both deep-level transient spectroscopy (DLTS) and lnI{sub 0} versus 1/k{sub b}T plots. The ideality factor almost remains constant in the temperature range 240-400 K, which shows the stability of the Schottky contact in this temperature range.

  5. Mixed convection from a discrete heat source in enclosures with two adjacent moving walls and filled with micropolar nanofluids

    Directory of Open Access Journals (Sweden)

    Sameh E. Ahmed

    2016-03-01

    Full Text Available This paper examines numerically the thermal and flow field characteristics of the laminar steady mixed convection flow in a square lid-driven enclosure filled with water-based micropolar nanofluids by using the finite volume method. While a uniform heat source is located on a part of the bottom of the enclosure, both the right and left sidewalls are considered adiabatic together with the remaining parts of the bottom wall. The upper wall is maintained at a relatively low temperature. Both the upper and left sidewalls move at a uniform lid-driven velocity and four different cases of the moving lid ordinations are considered. The fluid inside the enclosure is a water based micropolar nanofluid containing different types of solid spherical nanoparticles: Cu, Ag, Al2O3, and TiO2. Based on the numerical results, the effects of the dominant parameters such as Richardson number, nanofluid type, length and location of the heat source, solid volume fractions, moving lid orientations and dimensionless viscosity are examined. Comparisons with previously numerical works are performed and good agreements between the results are observed. It is found that the average Nusselt number along the heat source decreases as the heat source length increases while it increases when the solid volume fraction increases. Also, the results of the present study indicate that both the local and the average Nusselt numbers along the heat source have the highest value for the fourth case (C4. Moreover, it is observed that both the Richardson number and moving lid ordinations have a significant effect on the flow and thermal fields in the enclosure.

  6. Ocorrência de Diglotta brasiliensis (Coleoptera: Staphylinidae: Aleocharinae em duas praias estuarinas da Baía de Paranaguá, sul do Brasil Occurrence of Diglotta brasiliensis (Coleoptera: Staphylinidae: Aleocharinae in two estuarine beaches of Paranaguá Bay, southern Brazil

    Directory of Open Access Journals (Sweden)

    Leonardo C. da Rosa

    2008-09-01

    Full Text Available Nesta nota são apresentadas as principais características do hábictat de Diglotta brasiliensis Caron & Ribeiro-Costa, 2008, uma espécie recentemente descrita para a região Neotropical. Os indivíduos foram encontrados habitando uma faixa de aproximadamente 4 m de largura da zona intermareal superior de duas praias estuarinas (ambas localizadas no setor euhalino da baía, com as suas densidades variando de 13 a 80 indivíduos/m². Nesta faixa da praia os sedimentos estiveram compostos de areia média moderadamente a muito bem selecionada e com teor de umidade em torno de 6,5%. O teor de matéria orgânica e de carbonato de cálcio do sedimento variou entre 0,08 a 0,13% e 3,4 a 5,4%, respectivamente. Nesses locais, D. brasiliensis foi encontrada coexistindo com isópodes cirolanídeos do gênero Excirolana Richardson, 1912 (Isopoda: Cirolanidae.The main habitat characteristics of Diglotta brasiliensis Caron & Ribeiro-Costa, 2008, a recently described species from the Neotropical region, are provided. The specimens were found inhabiting a 4 m wide-strip at the upper intertidal zone of two estuarine sand beaches (both located in the euhaline sector of the bay, with densities ranging from 13 to 80 individuals/m². In this zone, sediment is composed by moderate to very well sorted median sand with moisture content around 6.5%. The sediment organic matter and calcium carbonate contents varied from 0.08 to 0.13% and from 3.4 to 5.4%, respectively. At these places, D. brasiliensis was found coexisting with cirolanid isopods of the genus Excirolana Richardson, 1912 (Isopoda: Cirolanidae.

  7. Inhomogeneous barrier height effect on the current–voltage characteristics of an Au/n-InP Schottky diode

    International Nuclear Information System (INIS)

    Zeghdar, Kamal; Dehimi, Lakhdar; Saadoune, Achour; Sengouga, Nouredine

    2015-01-01

    We report the current–voltage (I–V) characteristics of the Schottky diode (Au/n-InP) as a function of temperature. The SILVACO-TCAD numerical simulator is used to calculate the I–V characteristic in the temperature range of 280–400 K. This is to study the effect of temperature on the I–V curves and assess the main parameters that characterize the Schottky diode such as the ideality factor, the height of the barrier and the series resistance. The I–V characteristics are analyzed on the basis of standard thermionic emission (TE) theory and the inhomogeneous barrier heights (BHs) assuming a Gaussian distribution. It is shown that the ideality factor decreases while the barrier height increases with increasing temperature, on the basis of TE theory. Furthermore, the homogeneous BH value of approximately 0.524 eV for the device has been obtained from the linear relationship between the temperature-dependent experimentally effective BHs and ideality factors. The modified Richardson plot, according to the inhomogeneity of the BHs, has a good linearity over the temperature range. The evaluated Richardson constant A * was 10.32 A·cm −2 ·K −2 , which is close to the theoretical value of 9.4 A·cm −2 ·K −2 for n-InP. The temperature dependence of the I–V characteristics of the Au/n-InP Schottky diode have been successfully explained on the basis of the thermionic emission (TE) mechanism with a Gaussian distribution of the Schottky barrier heights (SBHs). Simulated I–V characteristics are in good agreement with the measurements [Korucu D, Mammadov T S. J Optoelectronics Advanced Materials, 2012, 14: 41]. The barrier height obtained using Gaussian Schottky barrier distribution is 0.52 eV, which is about half the band gap of InP. (paper)

  8. Inhomogeneous barrier height effect on the current-voltage characteristics of an Au/n-InP Schottky diode

    Science.gov (United States)

    Zeghdar, Kamal; Dehimi, Lakhdar; Saadoune, Achour; Sengouga, Nouredine

    2015-12-01

    We report the current-voltage (I-V) characteristics of the Schottky diode (Au/n-InP) as a function of temperature. The SILVACO-TCAD numerical simulator is used to calculate the I-V characteristic in the temperature range of 280-400 K. This is to study the effect of temperature on the I-V curves and assess the main parameters that characterize the Schottky diode such as the ideality factor, the height of the barrier and the series resistance. The I-V characteristics are analyzed on the basis of standard thermionic emission (TE) theory and the inhomogeneous barrier heights (BHs) assuming a Gaussian distribution. It is shown that the ideality factor decreases while the barrier height increases with increasing temperature, on the basis of TE theory. Furthermore, the homogeneous BH value of approximately 0.524 eV for the device has been obtained from the linear relationship between the temperature-dependent experimentally effective BHs and ideality factors. The modified Richardson plot, according to the inhomogeneity of the BHs, has a good linearity over the temperature range. The evaluated Richardson constant A* was 10.32 A·cm-2·K-2, which is close to the theoretical value of 9.4 A·cm-2·K-2 for n-InP. The temperature dependence of the I-V characteristics of the Au/n-InP Schottky diode have been successfully explained on the basis of the thermionic emission (TE) mechanism with a Gaussian distribution of the Schottky barrier heights (SBHs). Simulated I-V characteristics are in good agreement with the measurements [Korucu D, Mammadov T S. J Optoelectronics Advanced Materials, 2012, 14: 41]. The barrier height obtained using Gaussian Schottky barrier distribution is 0.52 eV, which is about half the band gap of InP.

  9. Analysis of the electrical characteristics of Zn/ZnSe/n-Si/Au-Sb structure fabricated using SILAR method as a function of temperature

    Energy Technology Data Exchange (ETDEWEB)

    Guezeldir, B. [Department of Physics, Faculty of Sciences, University of Atatuerk, 25240 Erzurum (Turkey); Saglam, M., E-mail: msaglam@atauni.edu.t [Department of Physics, Faculty of Sciences, University of Atatuerk, 25240 Erzurum (Turkey); Ates, A. [Department of Physics, Faculty of Sciences, University of Atatuerk, 25240 Erzurum (Turkey)

    2010-09-10

    The Successive Ionic Layer Adsorption and Reaction (SILAR) method has been used to deposit ZnSe thin film onto Si substrate to obtain the Zn/ZnSe/n-Si/Au-Sb sandwich structure. The X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) methods are used to investigate the structural and morphological properties of films. The XRD and SEM studies reveal that the films are covered well on Si substrate and have good polycrystalline structure and crystalline levels. The current-voltage (I-V) and capacitance-voltage (C-V) characteristics of this structure have been investigated as a function of the temperature (80-300 K) with 20 K steps. The ideality factor (n) and zero-bias barrier height ({Phi}{sub b0}) value which obtained from I-V curves were found to be strongly temperature dependent. While {Phi}{sub b0} increases with increasing temperature, n decreases. This behavior of the {Phi}{sub b0} and n can be attributed to barrier inhomogeneities at the metal-semiconductor (M-S) interface. The temperature dependence of the I-V characteristics of the Zn/ZnSe/n-Si/Au-Sb structure can reveal the existence of a double Gaussian distribution. The mean barrier height and the Richardson constant values are obtained as 0.925 eV and 1.140 eV, 130 A/cm{sup 2} K{sup 2} and 127 A/cm{sup 2} K{sup 2}, from the modified Richardson plot, respectively. Furthermore, the barrier height and carrier concentration are calculated from reverse bias C{sup -2}-V measurements at 200 kHz frequency as a function of the temperature.

  10. Topographic control on the nascent Mediterranean outflow

    Science.gov (United States)

    Gasser, M.; Pelegrí, J. L.; Nash, J. D.; Peters, H.; García-Lafuente, J.

    2011-12-01

    Data collected during a 12-day cruise in July 2009 served to examine the structure of the nascent Mediterranean Outflow Water (MOW) immediately west of the Espartel Sill, the westernmost sill in the Strait of Gibraltar. The MOW is characterized by high salinities (>37.0 and reaching 38.3) and high velocities (exceeding 1 m s-1 at 100 m above the seafloor), and follows a submerged valley along a 30 km stretch, the natural western extension of the strait. It is approx. 150 m thick and 10 km wide, and experiences a substantial drop from 420 to 530 m over a distance of some 3 km between two relatively flat regions. Measurements indicate that the nascent MOW behaves as a gravity current with nearly maximal traveling speed; if this condition is maintained, then the maximum MOW velocity would decrease slowly with distance from the Espartel Sill, remaining significantly high until the gravity current excess density is only a small fraction of its original value. The sharp pycnocline between the Mediterranean and the overlying North Atlantic Central waters is dynamically unstable, particularly where the flow interacts with the 100 m decrease in bottom depth. Here, subcritical gradient Richardson numbers coincide with the development of large interfacial undulations and billows. The very energetic downslope flow is likely responsible for the development of a narrow V-shaped channel downstream of the seafloor drop along the axis of the submerged valley, this probably being the very first erosional scour produced by the nascent MOW. The coincidence of subcritical gradient Richardson numbers with relatively high turbidity values above the channel flanks suggests it may be undergoing upstream erosion.

  11. A ring polymer molecular dynamics study of the isotopologues of the H + H2 reaction.

    Science.gov (United States)

    Suleimanov, Yury V; de Tudela, Ricardo Pérez; Jambrina, Pablo G; Castillo, Jesús F; Sáez-Rábanos, Vicente; Manolopoulos, David E; Aoiz, F Javier

    2013-03-14

    The inclusion of Quantum Mechanical (QM) effects such as zero point energy (ZPE) and tunneling in simulations of chemical reactions, especially in the case of light atom transfer, is an important problem in computational chemistry. In this respect, the hydrogen exchange reaction and its isotopic variants constitute an excellent benchmark for the assessment of approximate QM methods. In particular, the recently developed ring polymer molecular dynamics (RPMD) technique has been demonstrated to give very good results for bimolecular chemical reactions in the gas phase. In this work, we have performed a detailed RPMD study of the H + H(2) reaction and its isotopologues Mu + H(2), D + H(2) and Heμ + H(2), at temperatures ranging from 200 to 1000 K. Thermal rate coefficients and kinetic isotope effects have been computed and compared with exact QM calculations as well as with quasiclassical trajectories and experiment. The agreement with the QM results is good for the heaviest isotopologues, with errors ranging from 15% to 45%, and excellent for Mu + H(2), with errors below 15%. We have seen that RPMD is able to capture the ZPE effect very accurately, a desirable feature of any method based on molecular dynamics. We have also verified Richardson and Althorpe's prediction [J. O. Richardson and S. C. Althorpe, J. Chem. Phys., 2009, 131, 214106] that RPMD will overestimate thermal rates for asymmetric reactions and underestimate them for symmetric reactions in the deep tunneling regime. The ZPE effect along the reaction coordinate must be taken into account when assigning the reaction symmetry in the multidimensional case.

  12. A Robust Gold Deconvolution Approach for LiDAR Waveform Data Processing to Characterize Vegetation Structure

    Science.gov (United States)

    Zhou, T.; Popescu, S. C.; Krause, K.; Sheridan, R.; Ku, N. W.

    2014-12-01

    Increasing attention has been paid in the remote sensing community to the next generation Light Detection and Ranging (lidar) waveform data systems for extracting information on topography and the vertical structure of vegetation. However, processing waveform lidar data raises some challenges compared to analyzing discrete return data. The overall goal of this study was to present a robust de-convolution algorithm- Gold algorithm used to de-convolve waveforms in a lidar dataset acquired within a 60 x 60m study area located in the Harvard Forest in Massachusetts. The waveform lidar data was collected by the National Ecological Observatory Network (NEON). Specific objectives were to: (1) explore advantages and limitations of various waveform processing techniques to derive topography and canopy height information; (2) develop and implement a novel de-convolution algorithm, the Gold algorithm, to extract elevation and canopy metrics; and (3) compare results and assess accuracy. We modeled lidar waveforms with a mixture of Gaussian functions using the Non-least squares (NLS) algorithm implemented in R and derived a Digital Terrain Model (DTM) and canopy height. We compared our waveform-derived topography and canopy height measurements using the Gold de-convolution algorithm to results using the Richardson-Lucy algorithm. Our findings show that the Gold algorithm performed better than the Richardson-Lucy algorithm in terms of recovering the hidden echoes and detecting false echoes for generating a DTM, which indicates that the Gold algorithm could potentially be applied to processing of waveform lidar data to derive information on terrain elevation and canopy characteristics.

  13. Validación de un instrumento para medir el nivel de conocimiento sobre depresión mayor en médicos de atención primaria en Chiclayo, Perú

    Directory of Open Access Journals (Sweden)

    Aldo Ríos-Flores

    2013-01-01

    Full Text Available Objetivo: Diseñar y validar un instrumento para evaluar el nivel de conocimientos sobre Depresión mayor en médicos de atención primaria en Chiclayo. Material y Métodos: Estudio descriptivo, trasversal, tipo validación de un instrumento. El primer constructo se desarrolló en el 2010 en base al marco teórico y sometido a juicio de expertos. En el 2011 nuevamente se sometió el cuestionario a 12 expertos según la metodología Delphi, obteniéndose un constructo de 14 preguntas: 7 de diagnóstico y 7 de tratamiento; se realizó un estudio piloto para evaluar la inteligibilidad y pertinencia del instrumento. Se evaluó la confiabilidad con el coeficiente de Kuder-Richardson y el Alfa de Cronbach. La validez de constructo se realizó mediante análisis factorial. Se utilizó SPSS v. 15. Resultados: Se entrevistaron 34 médicos generales (90% y 6 alumnos (10% que habían terminado el curso de Salud mental: 36 (90% fueron varones; la media de edad fue de 37,5 ± 15 años. Los percentiles 25, 50 y 75 de la puntuación total del instrumento fueron: 4, 6 y 9, respectivamente. El Coeficiente de Kuder-Richardson fue 0,62; el Alfa de Cronbach de cada una de las preguntas fue mayor de 0,55. Las pruebas de Kaiser Meyer Olkin y de esfericidad de Bartlett mostraron que el instrumento era unidimensional. Conclusiones: Se obtuvo un instrumento válido, confiable y unidimensional para determinar el nivel de conocimientos sobre depresión mayor en médicos de atención primaria.

  14. Anomalous diffusion in geophysical and laboratory turbulence

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    A. Tsinober

    1994-01-01

    Full Text Available We present an overview and some new results on anomalous diffusion of passive scalar in turbulent flows (including those used by Richardson in his famous paper in 1926. The obtained results are based on the analysis of the properties of invariant quantities (energy, enstrophy, dissipation, enstrophy generation, helicity density, etc. - i.e. independent of the choice of the system of reference as the most appropriate to describe physical processes - in three different turbulent laboratory flows (grid-flow, jet and boundary layer, see Tsinober et al. (1992 and Kit et al. (1993. The emphasis is made on the relations between the asymptotic properties of the intermittency exponents of higher order moments of different turbulent fields (energy, dissipation, helicity, spontaneous breaking of isotropy and reflexional symmetry and the variability of turbulent diffusion in the atmospheric boundary layer, in the troposphere and in the stratosphere. It is argued that local spontaneous breaking of isotropy of turbulent flow results in anomalous scaling laws for turbulent diffusion (as compared to the scaling law of Richardson which are observed, as a rule, in different atmospheric layers from the atmospheric boundary layer (ABL to the stratosphere. Breaking of rotational symmetry is important in the ABL, whereas reflexional symmetry breaking is dominating in the troposphere locally and in the stratosphere globally. The results are of speculative nature and further analysis is necessary to validate or disprove the claims made, since the correspondence with the experimental results may occur for the wrong reasons as happens from time to time in the field of turbulence.

  15. Characterization of the inhomogeneous barrier distribution in a Pt/(100β-Ga2O3 Schottky diode via its temperature-dependent electrical properties

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    Guangzhong Jian

    2018-01-01

    Full Text Available β-Ga2O3 is an ultra-wide bandgap semiconductor with applications in power electronic devices. Revealing the transport characteristics of β-Ga2O3 devices at various temperatures is important for improving device performance and reliability. In this study, we fabricated a Pt/β-Ga2O3 Schottky barrier diode with good performance characteristics, such as a low ON-resistance, high forward current, and a large rectification ratio. Its temperature-dependent current–voltage and capacitance–voltage characteristics were measured at various temperatures. The characteristic diode parameters were derived using thermionic emission theory. The ideality factor n was found to decrease from 2.57 to 1.16 while the zero-bias barrier height Φb0 increased from 0.47 V to 1.00 V when the temperature was increased from 125 K to 350 K. This was explained by the Gaussian distribution of barrier height inhomogeneity. The mean barrier height Φ ¯ b0 = 1.27 V and zero-bias standard deviation σ0 = 0.13 V were obtained. A modified Richardson plot gave a Richardson constant A* of 36.02 A·cm−2·K−2, which is close to the theoretical value of 41.11 A·cm−2·K−2. The differences between the barrier heights determined using the capacitance–voltage and current–voltage curves were also in line with the Gaussian distribution of barrier height inhomogeneity.

  16. Software educativo: estrategias didácticas de educación ambiental para el aprendizaje significativo de estudiantes

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    Marisela Estanga Barrios

    2015-10-01

    Full Text Available La investigación se guió por un diseño cuasiexperimental, que incluyó un grupo control y el grupo objeto del experimento propiamente dicho. Su propósito consistió en determinar el efecto de un software educativo de estrategias de enseñanza de educación ambiental en el aprendizaje significativo de los estudiantes del lnstituto Pedagógico de Barquisimeto. Aplicando una preprueba para la equivalencia entre los grupos del experimento, al grupo experimental se le administró luego el contenido del programa mediante un software educativo, y al control, mediante una clase tradicional. A continuación, se aplicó una postprueba, validada por expertos y con muy alta confiabilidad por el coeficiente de Kuder-Richardson: 0,83. Los datos, procesados aplicando t de Student, permitieron aceptar la hipótesis de trabajo y concluir que el aprendizaje significativo de los estudiantes del grupo experimental se logró. AbstractThe following research is based on a quasi-experimental design, supported by a field research, which involved an experimental group; as well as a control group. The purpose of this research was to determine the effect of educational software on teaching strategies for environmental education, in significant learning experiences for students at Instituto Pedagógico de Barquisimeto. Both groups were applied a preliminary test for the equivalence between them; after that, the experimental group was given the content of the program through educational software; whilst the control group was taught a traditional class. Subsequently, a test validated by experts and with high reliability by the Kuder-Richardson co-efficient: 0,83, was given to both groups. The analysis of data was developed applying the statistic “T” of "student", it allows to accept the working hypothesis, and finally conclude that significant learning was achieved by the students of the experimental group.

  17. Gestión gerencial del docente directivo en las funciones: planificación, organización y dirección

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    Carlos Santana Soteldo

    2015-10-01

    Full Text Available El presente estudio tuvo como propósito analizar la gestión gerencial del docente directivo en cuanto a las funciones de planificación, organización y dirección. Se trata de una investigación de campo de carácter descriptivo y para obtener la información se aplicó un cuestionario con preguntas dicotómicas. El instrumento que se utilizó fue validado a través de la técnica de juicio de expertos y su confiabilidad se determinó mediante la aplicación de la fórmula de Kuder-Richardson (K-R20, obteniéndose la muy alta confiabilidad de 0.90. Los resultados permitieron conocer que la gestión gerencial del docente directivo en cuanto a la planificación, organización y dirección no es ejercida eficientemente, lo cual afecta a la institución y a todos sus actores. AbstractThe purpose of this research was to analyze the administrative management of the teacher director in terms of planning, organization and direction. It is about a field research of descriptive character in which a dichotomous questionnaire was applied in order to obtain the information. The instrument used was validated through the technique of experts’ opinion, and its reliability was determined by applying the Kuder-Richardson formula (K-R20 resulting in high reliability 0.90. The results revealed that the teacher director’s administrative management in terms of planning, organization and direction is not performed efficiently; this fact affects the institution and all the actors involved in it.

  18. Scaled Experimental Modeling of VHTR Plenum Flows

    Energy Technology Data Exchange (ETDEWEB)

    ICONE 15

    2007-04-01

    Abstract The Very High Temperature Reactor (VHTR) is the leading candidate for the Next Generation Nuclear Power (NGNP) Project in the U.S. which has the goal of demonstrating the production of emissions free electricity and hydrogen by 2015. Various scaled heated gas and water flow facilities were investigated for modeling VHTR upper and lower plenum flows during the decay heat portion of a pressurized conduction-cooldown scenario and for modeling thermal mixing and stratification (“thermal striping”) in the lower plenum during normal operation. It was concluded, based on phenomena scaling and instrumentation and other practical considerations, that a heated water flow scale model facility is preferable to a heated gas flow facility and to unheated facilities which use fluids with ranges of density to simulate the density effect of heating. For a heated water flow lower plenum model, both the Richardson numbers and Reynolds numbers may be approximately matched for conduction-cooldown natural circulation conditions. Thermal mixing during normal operation may be simulated but at lower, but still fully turbulent, Reynolds numbers than in the prototype. Natural circulation flows in the upper plenum may also be simulated in a separate heated water flow facility that uses the same plumbing as the lower plenum model. However, Reynolds number scaling distortions will occur at matching Richardson numbers due primarily to the necessity of using a reduced number of channels connected to the plenum than in the prototype (which has approximately 11,000 core channels connected to the upper plenum) in an otherwise geometrically scaled model. Experiments conducted in either or both facilities will meet the objectives of providing benchmark data for the validation of codes proposed for NGNP designs and safety studies, as well as providing a better understanding of the complex flow phenomena in the plenums.

  19. Two Types of Belief Report

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    Michael Hegarty

    2010-12-01

    -122. Oxford: Oxford University Press.DeRose, K. 1991. ‘Epistemic possibilities’. The Philosophical Review 100: 581–605.http://dx.doi.org/10.2307/2185175Eckhardt, R. 2005. ‘Too poor to mention: Subminimal eventualities and negative polarity items’. In C. Maienborn & A. Wöllstein (eds. ‘Event Arguments: Foundations and Applications’, 301–330. Tübingen: Max Niemeyer Verlag.Eckhardt, R. 2008. ‘The lower part of event ontology’. In J. Dölling, T. Heyde-Zybatow & M. Schäfer (eds. ‘Event Structures in Linguistic Form and Interpretation’, 477–491. Berlin: Walter de Gruyter.Egan, A. 2005. ‘Epistemic modals, relativism, and assertion’. In J. Gajewski, V. Hacquard, B. Nickel & S. Yalcin (eds. ‘New Work on Modality, MIT Working Papers in Linguistics v.51’, 35–62. MIT.Egan, A., Hawthorne, J. & Weatherson, B. 2005. ‘Epistemic modals in context’. In G. Preyer & G. Peter (eds. ‘Contextualism in Philosophy: Knowledge, Meaning and Truth’, 131–170. Oxford: Oxford University Press.Hacquard, V. 2006. Aspects of Modality. Ph.D. thesis, MIT.Hacquard, V. 2010. ‘On the event relativity of modal auxiliaries’. Natural Language Semantics 18: 79–114.http://dx.doi.org/10.1007/s11050-010-9056-4Heim, I. 1992. ‘Presupposition projection and the semantics of attitude verbs’. Journal of Semantics 9: 183–221.http://dx.doi.org/10.1093/jos/9.3.183Heim, I. & Kratzer, A. 1998. Semantics in Generative Grammar. Blackwell Publishers.Higginbotham, J. 1983. ‘The logic of perceptual reports: An extensional alternative to Situation Semantics’. The Journal of Philosophy 80: 100–127.http://dx.doi.org/10.2307/2026237Higginbotham, J. 1985. ‘On Semantics’. Linguistic Inquiry 16: 547–593.Higginbotham, J. 1989. ‘Elucidations of Meaning’. Linguistics and Philosophy 12: 465–517.http://dx.doi.org/10.1007/BF00632473Higginbotham, J. 2000. ‘On events in linguistic semantics’. In J. Higginbotham, F. Pianesi & A. C. Varzi (eds. ‘Speaking of Events

  20. Photoperiod and feeding behavior of the Antarctic fish Notothenia rossii (Perciformes: Nototheniidae and functional morphology of chemical and visual sensory structures used in foraging Comportamento alimentar do peixe antártico Notothenia rossii (Perciformes: Nototheniidae em diferentes fotoperíodos e a morfologia funcional das estruturas quimio-foto sensoriais usadas na detecção do alimento

    Directory of Open Access Journals (Sweden)

    Lucélia Donatti

    2008-06-01

    Full Text Available The influence of photoperiod on the ability of Notothenia rossii Richardson, 1844 to detect prey was studied experimentally. In 12L/12D there was the highest number of individuals stimulated visually and chemically while in 24D chemical perception was the same as that observed in 12L/12D, the latter being lower than in 24L. The ultrastructure of chemo- and photo-sensory structures, involved in the detection of food, was studied. The photoreceptor cells of the retina are single and double cones, and rods. Taste buds were concentrated in the central part of upper and lower lips. Their shape is even, but the size is variable. The olfactory rosette has a sensory and a non-sensory epithelium, being rich in different mucosubstances. The conclusion was that in different photoperiods there is a difference in the response to visual and chemical stimulation for prey detection and that all sensory systems are more stimulated in periods of more luminosity, mainly when there is an alternation between light and dark periods. Sensory organs are complex when compared to some other Antarctic fish such as Gobionotothen gibberifrons Lönnberg, 1905 and Ophthalmolycus amberensis Tomo, Marshoff & Torno, 1977 but similar to those of N. coriiceps Rchardson, 1844.A capacidade de Notothenia rossii Richardson, 1844 detectar presas in diferentes fotoperíodos (24L, 24D e 12L/12D foi estudada em tanques experimentais. Em 12L/12D houve um maior número de indivíduos estimulados visual e quimicamente enquanto que em 24D a percepção química foi a mesma que a observada em 12L/12D, sendo este ultimo inferior a 24L. A morfologia das estruturas quimio-foto sensoriais, envolvidas na detecção do alimento, foi estudada. As células fotorreceptoras da retina são os cones simples e duplos e os bastonetes. Os botões concentraram-se na região central dos lábios superior e inferior. Seu formato é constante, mas o tamanho é variável. A rosseta olfatória possui um epit

  1. Single ICMEs and Complex Transient Structures in the Solar Wind in 2010 - 2011

    Science.gov (United States)

    Rodkin, D.; Slemzin, V.; Zhukov, A. N.; Goryaev, F.; Shugay, Y.; Veselovsky, I.

    2018-05-01

    We analyze the statistics, solar sources, and properties of interplanetary coronal mass ejections (ICMEs) in the solar wind. The total number of coronal mass ejections (CMEs) registered in the Coordinated Data Analysis Workshops catalog (CDAW) during the first eight years of Cycle 24 was 61% larger than in the same period of Cycle 23, but the number of X-ray flares registered by the Geostationary Operational Environmental Satellite (GOES) was 20 % smaller because the solar activity was lower. The total number of ICMEs in the given period of Cycle 24 in the Richardson and Cane list was 29% smaller than in Cycle 23, which may be explained by a noticeable number of non-classified ICME-like events in the beginning of Cycle 24. For the period January 2010 - August 2011, we identify solar sources of the ICMEs that are included in the Richardson and Cane list. The solar sources of ICME were determined from coronagraph observations of the Earth-directed CMEs, supplemented by modeling of their propagation in the heliosphere using kinematic models (a ballistic and drag-based model). A detailed analysis of the ICME solar sources in the period under study showed that in 11 cases out of 23 (48%), the observed ICME could be associated with two or more sources. For multiple-source events, the resulting solar wind disturbances can be described as complex (merged) structures that are caused by stream interactions, with properties depending on the type of the participating streams. As a reliable marker to identify interacting streams and their sources, we used the plasma ion composition because it freezes in the low corona and remains unchanged in the heliosphere. According to the ion composition signatures, we classify these cases into three types: complex ejecta originating from weak and strong CME-CME interactions, as well as merged interaction regions (MIRs) originating from the CME high-speed stream (HSS) interactions. We describe temporal profiles of the ion composition for

  2. Verification of extended model of goal directed behavior applied on aggression

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    Katarína Vasková

    2016-01-01

    Full Text Available The study was aimed to verify Model of Goal Directed Behavior (EMGB by Perugini and Bagozzi (2001 applied on aggression by Richetin, Richardson and Boykin (2011. Two different studies were performed. Firstly original form of model was verified. In the second study, modification of EMGB through new conceptualization of scale of perceived behavioral control was executed. The research sample consisted together from 385 students of University of P.J. Šafárik and High school in Košice (182 respondents (78 men, 104 women with average age 20,84 years and standard deviation 1,94, who were involved in first study and 203 students (49 men and 154 women, with average age 19,71 and standard deviation 1,99 participated in second study who were administrated questionnaire by Richetin et al. (2011 and Richardson Conflict Response Questionnaire (Richardson & Green, 2006. Expectancy of comparable relationships between particular factors of EMGB in comparison to its published original version was verified. Data were analyzed by structural equation modeling. In first study was shown insufficient fit of EMGB model. There were hypothesized two main sources of problems. At first, weak relationship between attitudes and behavioral desire was shown. Following statistical procedures confirmed its direct impact on intention, what is in correspondence with another studies (see Leone, Perugini & Ercolani, 2004, Perugini & Bagozzi, 2001, Richetin et al., 2011. Second source of problems was identified in factor named perceived behavioral control. Difficulties from our point of view lied in conceptualization of the term and its subsequent measurement. In the second study was involved new conceptualization of control. It corresponded with Baumeister´s understanding of selfcontrol as asserting control over one´s emotions, thoughts and behavior. After this modification sufficient fit of EMGB was shown. Besides this, factor of self-control was the strongest predictor of

  3. Temperature and voltage dependence of barrier height and ideality factor in Au/0.07 graphene-doped PVA/n-Si structures

    Science.gov (United States)

    Altındal Yerişkin, S.; Balbaşı, M.; Demirezen, S.

    2017-04-01

    In this study, Au/0.07 graphene-doped PVA/n-Si structures were fabricated and current conduction mechanism in these structures were investigated in the temperature range of 80-380 K through forward bias current-voltage ( I- V) measurements. Main electrical parameters were extracted from I-V data. Zero-bias barrier height (\\overline{Φ}_{B0}) and ideality factor (n) were found strong functions of temperature and their values ranged from 0.234 eV and 4.98 (at 80 K) to 0.882 eV and 1.15 (at 380 K), respectively. Φ ap versus q/2k T plot was drawn to obtain an evidence of a Gaussian distribution of the barrier heights (BHs) and it revealed two distinct linear regions with different slopes and intercepts. The mean values of BH ( Φ Bo) and zero-bias standard deviation (σ s ) were obtained from the intercept and slope of the linear regions of this plot as 1.30 eV and 0.16 V for the first region (280-380 K) and 0.74 eV and 0.085 V for the second region (80-240 K), respectively. Thus, the values of \\overline{Φ}_{B0} and effective Richardson constant ( A*) were also found from the intercept and slope of the modified Richardson plot [ln( I s /T 2) - q 2 σ o 2 /2k 2 T 2 vs q/ kT] as 1.31 eV and 130 A/cm2 K2 for the first region and 0.76 eV and 922 A/cm2 K2 for the second region, respectively. The value of A* for the first region was very close to the theoretical value for n-Si (112 A/cm2 K2). The energy density distribution profile of surface states (Nss) was also extracted from the forward bias I-V data by taking into account voltage dependent effective BH (Φe) and n.

  4. Temperature dependent I-V characteristics of an Au/n-GaAs Schottky diode analyzed using Tung’s model

    Science.gov (United States)

    Korucu, Demet; Turut, Abdulmecit; Efeoglu, Hasan

    2013-04-01

    The current-voltage (I-V) characteristics of Au/n-GaAs contacts prepared with photolithography technique have been measured in the temperature range of 80-320 K. The ideality factor and barrier height (BH) values have remained almost unchanged between 1.04 and 1.10 and at a value of about 0.79 eV at temperatures above 200 K, respectively. Therefore, the ideality factor values near unity say that the experimental I-V data are almost independent of the sample temperature, that is, contacts have shown excellent Schottky diode behavior above 200 K. An abnormal decrease in the experimental BH Φb and an increase in the ideality factor with a decrease in temperature have been observed below 200 K. This behavior has been attributed to the barrier inhomogeneity by assuming a Gaussian distribution of nanometer-sized patches with low BH at the metal-semiconductor interface. The barrier inhomogeneity assumption is also confirmed by the linear relationship between the BH and the ideality factor. According to Tung’s barrier inhomogeneity model, it has been seen that the value of σT=7.41×10-5 cm2/3 V1/3from ideality factor versus (kT)-1 curve is in close agreement with σT=7.95×10-5 cm2/3 V1/3 value from the Φeff versus (2kT)-1 curve in the range of 80-200 K. The modified Richardson ln(J0/T2)-(qσT)2(Vb/η)2/3/[2(kT)2] versus (kT)-1 plot, from Tung’s Model, has given a Richardson constant value of 8.47 A cm-2 K-2which is in very close agreement with the known value of 8.16 A cm-2 K-2 for n-type GaAs; considering the effective patch area which is significantly lower than the entire geometric area of the Schottky contact, in temperature range of 80-200 K. Thus, it has been concluded that the use of Tung’s lateral inhomogeneity model is more appropriate to interpret the temperature-dependent I-V characteristics in the Schottky contacts.

  5. Criterios para el inicio de la convección y la formación de estructuras coherentes sobre Camagüey, Cuba Criteria for the onset of convection and the formation of coherent structures over Camaguey, Cuba

    Directory of Open Access Journals (Sweden)

    Nivian Quintana Rodríguez

    2011-09-01

    Full Text Available São apresentados os resultados de uma investigação sobre o processo de convecção de Rayleigh - Bénard partindo do cálculo dos números adimensionais de Rayleigh (Ra e de Richardson (Ri, com o objetivo de encontrar critérios que sejam representativos do disparo da convecção nas condições tropicais e insulares de Cuba. Os resultados são comparados com os obtidos empregando-se a técnica de ondeleta, e as observações de nebulosidade obtidas das imagens de satélites meteorológicos. Utilizaram-se as medições do mês de Junho do ano 2007 na torre de gradiente em Camagüey, e foram obtidos resultados como o número Ra crítico, (Ra = 1.32 x 10³. A velocidade vertical positiva foi empregada como condição necessária para o disparo da convecção. Encontrou-se que o Ra é um parâmetro indicador do tipo de convecção que deve formar-se, enquanto que o Ri é um indicador de sua intensidade.Results from an investigation on the physical process of Rayleigh-Bernard convection, based on the calculus of the dimensional Rayleigh (Ra and Richardson (Ri numbers, with the objective of finding criteria representative of the onset of convection in Cuba's tropical and insular conditions are shown. The obtained results are compared to those based on the Wavelets Technique and cloudiness derived from meteorological satellite images. Observations on June 2007 at Camagüey gradient Tower were used, and some results were derived, such as the critical (Ra = 1.32 x 10³. Positive value of the vertical velocity was set as the necessary condition for the onset of convection. It was found that Ra is an indicator of the convection type that should form, whereas Ri is an indicator of its intensity.

  6. Reconstruction of the two-dimensional gravitational potential of galaxy clusters from X-ray and Sunyaev-Zel'dovich measurements

    Science.gov (United States)

    Tchernin, C.; Bartelmann, M.; Huber, K.; Dekel, A.; Hurier, G.; Majer, C. L.; Meyer, S.; Zinger, E.; Eckert, D.; Meneghetti, M.; Merten, J.

    2018-06-01

    Context. The mass of galaxy clusters is not a direct observable, nonetheless it is commonly used to probe cosmological models. Based on the combination of all main cluster observables, that is, the X-ray emission, the thermal Sunyaev-Zel'dovich (SZ) signal, the velocity dispersion of the cluster galaxies, and gravitational lensing, the gravitational potential of galaxy clusters can be jointly reconstructed. Aims: We derive the two main ingredients required for this joint reconstruction: the potentials individually reconstructed from the observables and their covariance matrices, which act as a weight in the joint reconstruction. We show here the method to derive these quantities. The result of the joint reconstruction applied to a real cluster will be discussed in a forthcoming paper. Methods: We apply the Richardson-Lucy deprojection algorithm to data on a two-dimensional (2D) grid. We first test the 2D deprojection algorithm on a β-profile. Assuming hydrostatic equilibrium, we further reconstruct the gravitational potential of a simulated galaxy cluster based on synthetic SZ and X-ray data. We then reconstruct the projected gravitational potential of the massive and dynamically active cluster Abell 2142, based on the X-ray observations collected with XMM-Newton and the SZ observations from the Planck satellite. Finally, we compute the covariance matrix of the projected reconstructed potential of the cluster Abell 2142 based on the X-ray measurements collected with XMM-Newton. Results: The gravitational potentials of the simulated cluster recovered from synthetic X-ray and SZ data are consistent, even though the potential reconstructed from X-rays shows larger deviations from the true potential. Regarding Abell 2142, the projected gravitational cluster potentials recovered from SZ and X-ray data reproduce well the projected potential inferred from gravitational-lensing observations. We also observe that the covariance matrix of the potential for Abell 2142

  7. PERINGATAN DINI DAN DIAGNOSIS MUNCULNYA TURBULENSI CUACA CERAH DAN DAMPAKNYA PADA PESAWAT

    Directory of Open Access Journals (Sweden)

    Achmad Sasmito

    2014-06-01

    Full Text Available Salah satu informasi meteorologi yang sulit diprakirakan diantaranya yaitu terjadinya turbulensi pada saat cuaca cerah (TCC, sedangkan metoda yang lazim digunakan untuk mengetahui daerah TCC yaitu dengan menghitung bilangan Richardson (Ri.Untuk menduga lokasi terjadinya TCC yang  dialami oleh pesawat China Air Line, pada tanggal 20 September 2008 sekitar pukul 12.50 WIB yang terbang dari Taipe menuju Bali digunakan analisis data udara atas, satelit cuaca, dan prakiraan cuaca numerik model JMA (Numerical Weather Prediction/NWP. Hasil analisis data meteorologi tanggal 20 September 2008, pukul 11.00-13.00 WIB bahwa pesawat China Air Line diduga mengalami TCC lokasinya di sekitar Pulau Lulbu (Philipina/ posisi 7 - 15° LU, 115° - 120° BT, pada paras 300 - 400 mb, nilai bilangan Ri yaitu sekitar 200-290, ditengarai berada di daerah pertemuan dua (2 masa udara yaitu bagian bawah berasal dari barat kecepatan angin 10-15 knot, sedang bagian atas berasal dari timur kecepatan angin 15-25 knot, suhu puncak awan -70° C, sedang disebelahnya suhu + 10° C. Keadaan cuaca tersebut berkaitan dengan munculnya siklon tropis Hagupit di Philipina.   One of the difficult forecasted meteorological information such as the occurrence of Clear air turbulence (TCC. The methods commonly used to determine the TCC region that is by calculating the Richardson number (Ri. To infer the location of the TCC aircraft experienced by China Air Line, on 20 September 2008 at around 04:00 to 06:00 UTC flying from Taipei to Bali used the analysis of upper air data, weather satellites and numerical weather Prediction JMA model (Numerical Weather Prediction/NWP. The results of the analysis of meteorological data on September 20, 2008, at 04:00 to 06:00 UTC show that China Air Line occurred TCC loTCCion around the Lulbu island (Philipine, positions 7°-15° N, 115°-120° E, at 300-400 mb, the Ri number is about 200-290, which are loTCCed in areas suspected to be the confluence of two

  8. A sharp interface immersed boundary method for vortex-induced vibration in the presence of thermal buoyancy

    Science.gov (United States)

    Garg, Hemanshul; Soti, Atul K.; Bhardwaj, Rajneesh

    2018-02-01

    We report the development of an in-house fluid-structure interaction solver and its application to vortex-induced vibration (VIV) of an elastically mounted cylinder in the presence of thermal buoyancy. The flow solver utilizes a sharp interface immersed boundary method, and in the present work, we extend it to account for the thermal buoyancy using Boussinesq approximation and couple it with a spring-mass system of the VIV. The one-way coupling utilizes an explicit time integration scheme and is computationally efficient. We present benchmark code verifications of the solver for natural convection, mixed convection, and VIV. In addition, we verify a coupled VIV-thermal buoyancy problem at a Reynolds number, Re = 150. We numerically demonstrate the onset of the VIV in the presence of the thermal buoyancy for an insulated cylinder at low Re. The buoyancy is induced by two parallel plates, kept in the direction of flow and symmetrically placed around the cylinder. The plates are maintained at the hot and cold temperature to the same degree relative to the ambient. In the absence of the thermal buoyancy (i.e., the plates are at ambient temperature), the VIV does not occur for Re ≤ 20 due to stable shear layers. By contrast, the thermal buoyancy induces flow instability and the vortex shedding helps us to achieve the VIV at Re ≤ 20, lower than the critical value of Re (≈21.7), reported in the literature, for a self-sustained VIV in the absence of the thermal buoyancy. The present simulations show that the lowest Re to achieve VIV in the presence of the thermal buoyancy is around Re ≈ 3, at Richardson number, Ri = 1. We examine the effect of the reduced velocity (UR), mass ratio (m), Prandtl number (Pr), Richardson number (Ri) on the displacement of the cylinder, lift coefficient, oscillation frequency, the phase difference between displacement and lift force, and wake structures. We obtain a significantly larger vibration amplitude of the cylinder over a wide

  9. Monte Carlo modelling of damage to haemopoietic stem cells from internally deposited alpha-emitters

    International Nuclear Information System (INIS)

    Utteridge, T.D.; University of South Australia, Pooraka, SA; Charlton, D.E.; Turner, M.S.; Beddoe, A.H.; Leong, A. S-Y.; Milios, J.; Fazzalari, N.; To, L.B.

    1996-01-01

    Full text: Monte Carlo modelling of alpha particle radiation dose to haemopoietic stem cells from radon decay in human marrow fat cells was undertaken following Richardson et al's (Brit J Radiol, 64, 608-624, 1991) proposition that such exposure could induce leukaemia, and epidemiological observations that uranium miners have not developed an excess of leukaemia (Tomasek L. et al, Lancet, 341, 919-923, 1993). The dose to haemopoietic stem cells from alpha emitting radiopharmaceuticals proposed for radiotherapy is also important in risk assessment. Haemopoietic stem cells (presumed to be the targets for leukaemia) were identified as CD34+CD38- mononuclear cells (Terstappen LWMM et al, Blood, 77, 1218-1227, 1991) and their diameters measured using image analysis. The distribution of stem cell distances from fat cells was also measured. The model was used with Monte Carlo treatment of the alpha particle flux from radon and its short lived decay products to estimate (a) the dose and LET distributions for the three stem cell diameters; (b) the number of passages per hit; and (c) stem cell survival. The stem cell population exhibited a trimodal distribution, with mean diameters of 5.7, 11.6 and 14.8 μm; a trimodal distribution has previously been identified in mice (Visser J et al, Exper Hematol Today, 21-27, 1977). At 40% fat in a human lumbar vertebra 3 section, approximately half the stem cells were located on, or very close to the edge, of fat cells in marrow sections. This agrees with the predicted distribution of distances between fat and stem cells obtained using a 3-D model with randomly distributed stem cells. At an air activity of 20 Bq m -3 (ie the UK average indoor radon concentration used by Richardson et al mentioned above) about 0.1 stem cells per person-year were hit and survived; at 100 Bq m -3 about 1 stem cell per person-year was hit and survived. Across the range of radon concentrations encountered in residential and underground miner exposures

  10. The styles of the Finnish nuclear waste policy

    International Nuclear Information System (INIS)

    Kojo, Matti

    2010-09-01

    The Finnish government determined the aims and schedule for nuclear waste management in 1983. Nearly three decades later spent nuclear fuel (SNF) management is approaching the construction licensing phase of the repository, on schedule. The parliamentary decision on the final disposal of SNF was taken almost unanimously in 2001. The location of the SNF facility was chosen at the same time. The smoothness of this raises questions about the main factors behind the progress in Finland. The aim of the paper is to analyse the Finnish nuclear waste policy from the point of view of policy style. In the paper policy style is defined as 'the interaction between (a) the government's approach to problem-solving and (b) the relationship between government and the other actors in policy process'. According to this definition by Richardson, Gustafsson and Jordan, the focus of style is both on policymaking and on implementation. The policy style approach is used to identify the standard operating procedures of Finnish nuclear waste policy. The paper aims to contribute to the discussion on the formation of national nuclear waste policy and its institutions by analysing the Finnish case

  11. Relevant energy scale of color confinement from lattice QCD

    International Nuclear Information System (INIS)

    Yamamoto, Arata; Suganuma, Hideo

    2009-01-01

    We propose a new lattice framework to extract the relevant gluonic energy scale of QCD phenomena which is based on a 'cut' on link variables in momentum space. This framework is expected to be broadly applicable to all lattice QCD calculations. Using this framework, we quantitatively determine the relevant energy scale of color confinement, through the analyses of the quark-antiquark potential and meson masses. The relevant energy scale of color confinement is found to be below 1.5 GeV in the Landau gauge. In fact, the string tension is almost unchanged even after cutting off the high-momentum gluon component above 1.5 GeV. When the relevant low-energy region is cut, the quark-antiquark potential is approximately reduced to a Coulomb-like potential, and each meson becomes a quasifree quark pair. As an analytical model calculation, we also investigate the dependence of the Richardson potential on the cut, and find the consistent behavior with the lattice result.

  12. Diurnal variations of the Martian surface layer meteorological parameters during the first 45 sols at two Viking Lander sites

    International Nuclear Information System (INIS)

    Sutton, J.L.; Leovy, C.B.; Tillman, J.E.

    1978-01-01

    Wind speed, ambient and surface temperatures from both Viking Landers have been used to compute bulk Richardson numbers and Monin-Obukhov lengths during the earliest phase of the Mars missions. These parameters are used to estimate drag and heat transfer coefficients, friction velocities and surface heat fluxes at the two sites. The principal uncertainty is in the specification of the roughness length. Maximum heat fluxes occur near local noon at both sites, and are estimated to be in the range 15--20 W m -2 at the Viking 1 site and 10--15 W m -2 at the Viking 2 site. Maximum values of friction velocity occur in late morning at Viking 1 and are estimated to be 0.4--0.6 m s -1 . They occur shortly after drawn at the Viking 2 site where peak values are estimated to be in the range 0.25--0.35 m s -1 . Extension of these calculations to later times during the mission will require allowance for dust opacity effects in the estimation of surface temperature and in the correction of radiation errors of the Viking 2 temperature sensor

  13. The influence of surface roughness and turbulence on heat fluxes from an oil palm plantation in Jambi, Indonesia

    Science.gov (United States)

    June, Tania; Meijide, Ana; Stiegler, Christian; Purba Kusuma, Alan; Knohl, Alexander

    2018-05-01

    Oil palm plantations are expanding vastly in Jambi, resulted in altered surface roughness and turbulence characteristics, which may influence exchange of heat and mass. Micrometeorological measurements above oil palm canopy were conducted for the period 2013–2015. The oil palms were 12.5 years old, canopy height 13 meters and 1.5 years old canopy height 2.5 m. We analyzed the influence of surface roughness and turbulence strenght on heat (sensible and latent) fluxes by investigating the profiles and gradient of wind speed, and temperature, surface roughness (roughness length, zo, and zero plane displacement, d), and friction velocity u*. Fluxes of heat were calculated using profile similarity methods taking into account atmospheric stability calculated using Richardson number Ri and the generalized stability factor ζ. We found that roughness parameters (zo, d, and u*) directly affect turbulence in oil palm canopy and hence heat fluxes; they are affected by canopy height, wind speed and atmospheric stability. There is a negative trend of d towards air temperature above the oil palm canopy, indicating the effect of plant volume and height in lowering air temperature. We propose studying the relation between zero plane displacement d with a remote sensing vegetation index for scaling up this point based analysis.

  14. Restoration of motion-blurred image based on border deformation detection: a traffic sign restoration model.

    Directory of Open Access Journals (Sweden)

    Yiliang Zeng

    Full Text Available Due to the rapid development of motor vehicle Driver Assistance Systems (DAS, the safety problems associated with automatic driving have become a hot issue in Intelligent Transportation. The traffic sign is one of the most important tools used to reinforce traffic rules. However, traffic sign image degradation based on computer vision is unavoidable during the vehicle movement process. In order to quickly and accurately recognize traffic signs in motion-blurred images in DAS, a new image restoration algorithm based on border deformation detection in the spatial domain is proposed in this paper. The border of a traffic sign is extracted using color information, and then the width of the border is measured in all directions. According to the width measured and the corresponding direction, both the motion direction and scale of the image can be confirmed, and this information can be used to restore the motion-blurred image. Finally, a gray mean grads (GMG ratio is presented to evaluate the image restoration quality. Compared to the traditional restoration approach which is based on the blind deconvolution method and Lucy-Richardson method, our method can greatly restore motion blurred images and improve the correct recognition rate. Our experiments show that the proposed method is able to restore traffic sign information accurately and efficiently.

  15. A novel data processing technique for image reconstruction of penumbral imaging

    Science.gov (United States)

    Xie, Hongwei; Li, Hongyun; Xu, Zeping; Song, Guzhou; Zhang, Faqiang; Zhou, Lin

    2011-06-01

    CT image reconstruction technique was applied to the data processing of the penumbral imaging. Compared with other traditional processing techniques for penumbral coded pinhole image such as Wiener, Lucy-Richardson and blind technique, this approach is brand new. In this method, the coded aperture processing method was used for the first time independent to the point spread function of the image diagnostic system. In this way, the technical obstacles was overcome in the traditional coded pinhole image processing caused by the uncertainty of point spread function of the image diagnostic system. Then based on the theoretical study, the simulation of penumbral imaging and image reconstruction was carried out to provide fairly good results. While in the visible light experiment, the point source of light was used to irradiate a 5mm×5mm object after diffuse scattering and volume scattering. The penumbral imaging was made with aperture size of ~20mm. Finally, the CT image reconstruction technique was used for image reconstruction to provide a fairly good reconstruction result.

  16. Assessment of a surface-layer parameterization scheme in an atmospheric model for varying meteorological conditions

    Directory of Open Access Journals (Sweden)

    T. J. Anurose

    2014-06-01

    Full Text Available The performance of a surface-layer parameterization scheme in a high-resolution regional model (HRM is carried out by comparing the model-simulated sensible heat flux (H with the concurrent in situ measurements recorded at Thiruvananthapuram (8.5° N, 76.9° E, a coastal station in India. With a view to examining the role of atmospheric stability in conjunction with the roughness lengths in the determination of heat exchange coefficient (CH and H for varying meteorological conditions, the model simulations are repeated by assigning different values to the ratio of momentum and thermal roughness lengths (i.e. z0m/z0h in three distinct configurations of the surface-layer scheme designed for the present study. These three configurations resulted in differential behaviour for the varying meteorological conditions, which is attributed to the sensitivity of CH to the bulk Richardson number (RiB under extremely unstable, near-neutral and stable stratification of the atmosphere.

  17. Experimental investigation of natural convection in a core of a marine reactor in rolling motion

    International Nuclear Information System (INIS)

    Murata, Hiroyuki; Sawada, Ken-ichi; Kobayashi, Michiyuki

    2000-01-01

    A series of single-phase natural circulation experiments in a simulated marine reactor mounted on a rolling bed was performed and the average Nusselt number in the core was evaluated in order to investigate effects of the rolling motion on the heat transfer in the core. Heat transfer with an upright attitude is well correlated with the Rayleigh number and is slightly lower than El-Genk's correlation. Heat transfer in the core is not affected by the inclination angle because the inclination of the present experiment is not large enough to cause any remarkable changes in the flow pattern of the core. Heat transfer in the core is enhanced by the rolling motion which is thought to cause internal flow in the core. Heat transfer during the rolling motion is correlated with the Richardson number for rolling motion, Ri R , and is classified into three regimes: (1) region A (0.05 R ≤0.3) where heat transfer is dominated by the inertial force due to the rolling motion; (2) region B (0.3 R ≤2) where heat transfer is affected by the combined effect of the inertial force and natural convection; and (3) region C (Ri R >2) where heat transfer is affected only by the natural convection. (author)

  18. Advective and diapycnal diffusive oceanic flux in Tenerife - La Gomera Channel

    Science.gov (United States)

    Marrero-Díaz, A.; Rodriguez-Santana, A.; Hernández-Arencibia, M.; Machín, F.; García-Weil, L.

    2012-04-01

    During the year 2008, using the commercial passenger ship Volcán de Tauce of the Naviera Armas company several months, it was possible to obtain vertical profiles of temperature from expandable bathythermograph probes in eight stations across the Tenerife - La Gomera channel. With these data of temperature we have been estimated vertical sections of potential density and geostrophic transport with high spatial and temporal resolution (5 nm between stations, and one- two months between cruises). The seasonal variability obtained for the geostrophic transport in this channel shows important differences with others Canary Islands channels. From potential density and geostrophic velocity data we estimated the vertical diffusion coefficients and diapycnal diffusive fluxes, using a parameterization that depends of Richardson gradient number. In the center of the channel and close to La Gomera Island, we found higher values for these diffusive fluxes. Convergence and divergence of these fluxes requires further study so that we can draw conclusions about its impact on the distribution of nutrients in the study area and its impact in marine ecosystems. This work is being used in research projects TRAMIC and PROMECA.

  19. Modelling and analysis of turbulent datasets using Auto Regressive Moving Average processes

    International Nuclear Information System (INIS)

    Faranda, Davide; Dubrulle, Bérengère; Daviaud, François; Pons, Flavio Maria Emanuele; Saint-Michel, Brice; Herbert, Éric; Cortet, Pierre-Philippe

    2014-01-01

    We introduce a novel way to extract information from turbulent datasets by applying an Auto Regressive Moving Average (ARMA) statistical analysis. Such analysis goes well beyond the analysis of the mean flow and of the fluctuations and links the behavior of the recorded time series to a discrete version of a stochastic differential equation which is able to describe the correlation structure in the dataset. We introduce a new index Υ that measures the difference between the resulting analysis and the Obukhov model of turbulence, the simplest stochastic model reproducing both Richardson law and the Kolmogorov spectrum. We test the method on datasets measured in a von Kármán swirling flow experiment. We found that the ARMA analysis is well correlated with spatial structures of the flow, and can discriminate between two different flows with comparable mean velocities, obtained by changing the forcing. Moreover, we show that the Υ is highest in regions where shear layer vortices are present, thereby establishing a link between deviations from the Kolmogorov model and coherent structures. These deviations are consistent with the ones observed by computing the Hurst exponents for the same time series. We show that some salient features of the analysis are preserved when considering global instead of local observables. Finally, we analyze flow configurations with multistability features where the ARMA technique is efficient in discriminating different stability branches of the system

  20. Seasonal variability of the diapycnal mixing in the Canary Islands channels

    Science.gov (United States)

    Rodríguez-Santana, Angel; Marrero-Díaz, Angeles; Machín, Francisco Jose; García-Weil, Luis; Sangrà, Pablo; Vélez-Belchí, Pedro; Fraile-Nuez, Eugenio; Estrada-Allis, Sheila

    2014-05-01

    Trimonthly surveys of XBT and XCTD (Expandable Bathytermograph and Conductivity-Temperature-Depth) crossing the whole Canary Islands channels were carried out (projects TRAMIC and PROMECA) from November 2012 until September 2013 using opportunity ships (Naviera Armas Ferries). With this data set and using salinity analytical relationships (Machín et al, 2010), vertical sections of temperature and potential density were obtained for each channel and season. In order to estimate the intensity of the diapycnal mixing in the first 500 m of the pycnocline, vertical sections of Thorpe length scale, Turner angle and gradient Richardson number (from the geostrophic vertical shear) were calculated for all the cases. The first results show how the diapycnal mixing due to the vertical shear instabilities is more intense close to the islands and in summer when the seasonal pycnocline is present. Mixing due to double diffusion processes (salt fingers) was found without sizable changes in the permanent pycnocline. Net turbulence diffusivities and diapycnal diffusive fluxes with their variability spatial and temporal will be estimate for each channel taking into account that processes of double diffusion and turbulence induced by vertical shear are present at the same time. Additionally the results obtained from hydrographic data from the cruise RAPROCAN-2013 (IEO) (October 2013) around Canary Islands will be used to compare them with the channels results. This work was co-funded by Canary Government (TRAMIC project: PROID20100092), European Union (FEDER) and Spanish Government (PROMECA: CTM2008-04057/MAR and CTM2009-06993-E/MAR)

  1. Relationship between SEP Peak intensity and CME Acceleration, Speed and Width

    Science.gov (United States)

    Xie, H.; St Cyr, O. C.; Makela, P. A.; Gopalswamy, N.

    2017-12-01

    We study the large solar energetic particle (SEP) events that were detected by GOES in the >10 MeV energy channel during December 2006 to January 2016. Data used in this study includes the Solar Electron Proton Telescope (SEPT) and High Energy Telescopes (HET) on STEREO A and B, the Electron, Proton, and Alpha Monitor (EPAM) on ACE, and the Energetic and Relativistic Nuclei and Electron instrument (ERNE) on SOHO. By choosing the smallest connection angles between SEP solar locations and magnetic foot-points of each spacecraft, we divide SEP events as SOHO SEPs or STEREO SEPs. We then compute the SEP peak intensity I0 at the center of the Gausssian using the Gausssian expression from Richardson et al. (2014) and study the relationship between SEP electron and proton peak intensity and CME acceleration, speed and width. By using I0 derived from multi-spacecraft observations we found that the correlations between SEP peak intensity and CME acceleration and speed improved. We also found that this correlation can be further improved by taking into account the effects of CME width and its solar source latitude. The implication for the SEP forecast of our obtained results will be discussed.

  2. A COMPARISON OF ELEMENTAL ABUNDANCE RATIOS IN SEP EVENTS IN FAST AND SLOW SOLAR WIND REGIONS

    International Nuclear Information System (INIS)

    Kahler, S. W.; Tylka, A. J.; Reames, D. V.

    2009-01-01

    The solar energetic (E > 1 MeV nucleon -1 ) particles (SEPs) observed in gradual events at 1 AU are assumed to be accelerated by coronal/interplanetary shocks from ambient thermal or suprathermal seed particles. If so, then the elemental abundances of SEPs produced in different solar wind (SW) stream types (transient, fast, and slow) might be systematically distinguished from each other. We look for these differences in SEP energy spectra and in elemental abundance ratios (including Mg/Ne and Fe/C, which compare low/high first ionization potential elements), in a large number of SEP time intervals over the past solar cycle. The SW regions are characterized by the three-component stream classification of Richardson et al. Our survey shows no significant compositional or energy spectral differences in the 5-10 MeV nucleon -1 range for SEP events of different SW stream types. This result extends the earlier finding that SEP events are observed frequently in fast SW streams, although their higher Alfven and SW flow speeds should constrain SEP production by coronal mass ejection-driven shocks in those regions. We discuss the implications of our results for shock seed populations and cross-field propagation.

  3. Trends in abundance of collared lemmings near Cape Churchill, Manitoba, Canada

    Science.gov (United States)

    Reiter, M.E.; Andersen, D.E.

    2008-01-01

    Regular, multiannual cycles observed in the population abundance of small mammals in many arctic and subarctic ecosystems have stimulated substantial research, particularly among population ecologists. Hypotheses of mechanisms generating regular cycles include predator-prey interactions, limitation of food resources, and migration or dispersal, as well as abiotic factors such as cyclic climatic variation and environmental stochasticity. In 2004 and 2005, we used indirect methods to estimate trends in population size of Richardson's collared lemmings (Dicrostonyx richardsoni) retrospectively, and evaluated the extent of synchrony between lemming populations at 2 coastal tundra study areas separated by approximately 60 km near Cape Churchill, Manitoba, Canada. We collected scars on willow plants (Salix) resulting from lemming feeding. Ages of scars ranged from 0 to 13 years at both study areas. Scar-age frequency appeared cyclic and we used nonlinear Poisson regression to model the observed scar-age frequency. Lemming populations cycled with 2.8-year periodicity and the phase of the cycle was synchronous between the 2 study areas. We suggest that our approach could be applied in multiple settings and may provide the most efficient way to gather data on small mammals across both space and time in a diversity of landscapes. ?? 2008 American Society of Mammalogists.

  4. Onset of transition from laminar to chaos in MHD mixed convection of a lid-driven trapezoidal cavity filled with Cu-water nanofluid

    Energy Technology Data Exchange (ETDEWEB)

    Azam, Mohammad, E-mail: azam09mebuet@gmail.com; Hasanuzzaman, Md., E-mail: hasanuzzaman138@gmail.com; Saha, Sumon, E-mail: sumonsaha@me.buet.ac.bd [Department of Mechanical Engineering, Bangladesh University of Engineering and Technology, Dhaka 1000 (Bangladesh)

    2016-07-12

    The present study investigates the thermal mixing scenarios of steady magneto-hydrodynamic (MHD) mixed convection in a two-dimensional lid-driven trapezoidal cavity filled with Cu-water nanofluid. The top wall of the cavity slides with a uniform velocity from left to right direction, while the other walls are fixed. The bottom wall is kept with a constant higher temperature than the top one. The governing mass, momentum and energy equations are expressed in non-dimensional forms and Galerkin finite element method has been employed to solve these equations. Special attention is paid on investigating the onset of transition from laminar to chaos at pure mixed convection case. Hence, the computations are carried out for a wide range of Reynolds numbers (Re = 0.1 − 400) and Grashof numbers (Gr = 10{sup −2} − 1.6 × 10{sup 5}) at unity Richardson number and fixed Hartmann number (Ha = 10). The variation of average Nusselt number of the bottom heated wall indicates the influence of governing parameters (Re and Gr) on heat transfer characteristics. The results are presented and explained through the visualisation of isotherms, streamlines and heatlines.

  5. Characterizing the Severe Turbulence Environments Associated With Commercial Aviation Accidents: A Real-Time Turbulence Model (RTTM) Designed for the Operational Prediction of Hazardous Aviation Turbulence Environments

    Science.gov (United States)

    Kaplan, Michael L.; Lux, Kevin M.; Cetola, Jeffrey D.; Huffman, Allan W.; Riordan, Allen J.; Slusser, Sarah W.; Lin, Yuh-Lang; Charney, Joseph J.; Waight, Kenneth T.

    2004-01-01

    Real-time prediction of environments predisposed to producing moderate-severe aviation turbulence is studied. We describe the numerical model and its postprocessing system designed for said prediction of environments predisposed to severe aviation turbulence as well as presenting numerous examples of its utility. The numerical model is MASS version 5.13, which is integrated over three different grid matrices in real time on a university work station in support of NASA Langley Research Center s B-757 turbulence research flight missions. The postprocessing system includes several turbulence-related products, including four turbulence forecasting indices, winds, streamlines, turbulence kinetic energy, and Richardson numbers. Additionally, there are convective products including precipitation, cloud height, cloud mass fluxes, lifted index, and K-index. Furthermore, soundings, sounding parameters, and Froude number plots are also provided. The horizontal cross-section plot products are provided from 16 000 to 46 000 ft in 2000-ft intervals. Products are available every 3 hours at the 60- and 30-km grid interval and every 1.5 hours at the 15-km grid interval. The model is initialized from the NWS ETA analyses and integrated two times a day.

  6. Hybrid graphene/silicon Schottky photodiode with intrinsic gating effect

    Science.gov (United States)

    Di Bartolomeo, Antonio; Luongo, Giuseppe; Giubileo, Filippo; Funicello, Nicola; Niu, Gang; Schroeder, Thomas; Lisker, Marco; Lupina, Grzegorz

    2017-06-01

    We propose a hybrid device consisting of a graphene/silicon (Gr/Si) Schottky diode in parallel with a Gr/SiO2/Si capacitor for high-performance photodetection. The device, fabricated by transfer of commercial graphene on low-doped n-type Si substrate, achieves a photoresponse as high as 3 \\text{A} {{\\text{W}}-1} and a normalized detectivity higher than 3.5× {{10}12} \\text{cm} \\text{H}{{\\text{z}}1/2} {{\\text{W}}-1} in the visible range. It exhibits a photocurrent exceeding the forward current because photo-generated minority carriers, accumulated at Si/SiO2 interface of the Gr/SiO2/Si capacitor, diffuse to the Gr/Si junction. We show that the same mechanism, when due to thermally generated carriers, although usually neglected or disregarded, causes the increased leakage often measured in Gr/Si heterojunctions. We perform extensive I-V and C-V characterization at different temperatures and we measure a zero-bias Schottky barrier height of 0.52 eV at room temperature, as well as an effective Richardson constant A **  =  4× {{10}-5} \\text{A} \\text{c}{{\\text{m}}-2} {{\\text{K}}-2} and an ideality factor n≈ 3.6 , explained by a thin (<1 nm) oxide layer at the Gr/Si interface.

  7. Development of evaluation method for heat removal design of dry storage facilities. pt. 1. Heat removal test on vault storage system of cross flow type

    International Nuclear Information System (INIS)

    Sakamoto, Kazuaki; Koga, Tomonari; Wataru, Masumi; Hattori, Yasuo

    1997-01-01

    The report describes the result of heat removal test of passive cooling vault storage system of cross flow type using 1/5 scale model. Based on a prospect of steady increase in the amount of spent fuel, it is needed to establish large capacity dry storage technologies for spent fuel. Air flow patterns, distributions of air temperature and velocity were measured, by which heat removal characteristics of the system were made clear. Air flow patterns in the storage module depended on the ratio of the buoyant force to the inertial force; the former generated by the difference of air temperatures and the height of the storage module, the latter by the difference of air densities between the outlet of the storage module and ambience and the height of the chimney of the storage facility. A simple method to estimate air flow patterns in the storage module was suggested, where Ri(Richardson) number was applied to represent the ratio. Moreover, heat transfer coefficient from a model of storage tube to cooling air was evaluated, and it was concluded that the generalized expression of heat transfer coefficient for common heat exchangers could be applied to the vault storage system of cross flow type, in which dozens of storage tubes were placed in a storage module. (author)

  8. Convex unwraps its first grown-up supercomputer

    Energy Technology Data Exchange (ETDEWEB)

    Manuel, T.

    1988-03-03

    Convex Computer Corp.'s new supercomputer family is even more of an industry blockbuster than its first system. At a tenfold jump in performance, it's far from just an incremental upgrade over its first minisupercomputer, the C-1. The heart of the new family, the new C-2 processor, churning at 50 million floating-point operations/s, spawns a group of systems whose performance could pass for some fancy supercomputers-namely those of the Cray Research Inc. family. When added to the C-1, Convex's five new supercomputers create the C series, a six-member product group offering a performance range from 20 to 200 Mflops. They mark an important transition for Convex from a one-product high-tech startup to a multinational company with a wide-ranging product line. It's a tough transition but the Richardson, Texas, company seems to be doing it. The extended product line propels Convex into the upper end of the minisupercomputer class and nudges it into the low end of the big supercomputers. It positions Convex in an uncrowded segment of the market in the $500,000 to $1 million range offering 50 to 200 Mflops of performance. The company is making this move because the minisuper area, which it pioneered, quickly became crowded with new vendors, causing prices and gross margins to drop drastically.

  9. Microbiological Spoilage of High-Sugar Products

    Science.gov (United States)

    Thompson, Sterling

    The high-sugar products discussed in this chapter are referred to as chocolate, sugar confectionery (non-chocolate), liquid sugars, sugar syrups, and honey. Products grouped in the sugar confectionery category include hard candy, soft/gummy candy, caramel, toffee, licorice, marzipan, creams, jellies, and nougats. A common intrinsic parameter associated with high-sugar products is their low water activity (a w), which is known to inhibit the growth of most spoilage and pathogenic bacteria. However, spoilage can occur as a result of the growth of osmophilic yeasts and xerophilic molds (Von Richter, 1912; Anand & Brown, 1968; Brown, 1976). The a w range for high-sugar products is between 0.20 and 0.80 (Banwart, 1979; Richardson, 1987; Lenovich & Konkel, 1992; ICMSF, 1998; Jay, Loessner, & Golden, 2005). Spoilage of products, such as chocolate-covered cherries, results from the presence of yeasts in the liquid sugar brine or the cherry. Generally, the spoiled product will develop leakers. The chocolate covering the cherry would not likely be a source of yeast contamination.

  10. Electronic Properties of DNA-Based Schottky Barrier Diodes in Response to Alpha Particles.

    Science.gov (United States)

    Al-Ta'ii, Hassan Maktuff Jaber; Periasamy, Vengadesh; Amin, Yusoff Mohd

    2015-05-21

    Detection of nuclear radiation such as alpha particles has become an important field of research in recent history due to nuclear threats and accidents. In this context; deoxyribonucleic acid (DNA) acting as an organic semiconducting material could be utilized in a metal/semiconductor Schottky junction for detecting alpha particles. In this work we demonstrate for the first time the effect of alpha irradiation on an Al/DNA/p-Si/Al Schottky diode by investigating its current-voltage characteristics. The diodes were exposed for different periods (0-20 min) of irradiation. Various diode parameters such as ideality factor, barrier height, series resistance, Richardson constant and saturation current were then determined using conventional, Cheung and Cheung's and Norde methods. Generally, ideality factor or n values were observed to be greater than unity, which indicates the influence of some other current transport mechanism besides thermionic processes. Results indicated ideality factor variation between 9.97 and 9.57 for irradiation times between the ranges 0 to 20 min. Increase in the series resistance with increase in irradiation time was also observed when calculated using conventional and Cheung and Cheung's methods. These responses demonstrate that changes in the electrical characteristics of the metal-semiconductor-metal diode could be further utilized as sensing elements to detect alpha particles.

  11. Electronic Properties of DNA-Based Schottky Barrier Diodes in Response to Alpha Particles

    Directory of Open Access Journals (Sweden)

    Hassan Maktuff Jaber Al-Ta'ii

    2015-05-01

    Full Text Available Detection of nuclear radiation such as alpha particles has become an important field of research in recent history due to nuclear threats and accidents. In this context; deoxyribonucleic acid (DNA acting as an organic semiconducting material could be utilized in a metal/semiconductor Schottky junction for detecting alpha particles. In this work we demonstrate for the first time the effect of alpha irradiation on an Al/DNA/p-Si/Al Schottky diode by investigating its current-voltage characteristics. The diodes were exposed for different periods (0–20 min of irradiation. Various diode parameters such as ideality factor, barrier height, series resistance, Richardson constant and saturation current were then determined using conventional, Cheung and Cheung’s and Norde methods. Generally, ideality factor or n values were observed to be greater than unity, which indicates the influence of some other current transport mechanism besides thermionic processes. Results indicated ideality factor variation between 9.97 and 9.57 for irradiation times between the ranges 0 to 20 min. Increase in the series resistance with increase in irradiation time was also observed when calculated using conventional and Cheung and Cheung’s methods. These responses demonstrate that changes in the electrical characteristics of the metal-semiconductor-metal diode could be further utilized as sensing elements to detect alpha particles.

  12. Dayside atmospheric structure of HD209458b from Spitzer eclipses

    Science.gov (United States)

    Reinhard, Matthew; Harrington, Joseph; Challener, Ryan; Cubillos, Patricio; Blecic, Jasmina

    2017-10-01

    HD209458b is a hot Jupiter with a radius of 1.26 ± 0.08 Jupiter radii (Richardson et al, 2006) and a mass of 0.64 ± 0.09 Jupiter masses (Snellen et al, 2010). The planet orbits a G0 type star with an orbital period of 3.52472 ± 2.81699e-05 days, and a relatively low eccentricity of 0.0082 +0.0078/-0.0082 (Wang and Ford 2013). We report the analysis of observations of HD209458b during eclipse, taken in the 3.6 and 4.5 micron channels by the Spitzer Space Telescope's Infrared Array Camera (Program 90186). We produce a photometric light curve of the eclipses in both channels, using our Photometry for Orbits Eclipses and Transits (POET) code, and calculate the brightness temperatures and eclipse depths. We also present best estimates of the atmospheric parameters of HD209458b using our Bayesian Atmospheric Radiative Transfer (BART) code. These are some preliminary results of what will be an analysis of all available Spitzer data for HD209458b. Spitzer is operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. This work was supported by NASA Planetary Atmospheres grant NX12AI69G and NASA Astrophysics Data Analysis Program grant NNX13AF38G.

  13. Effect of stable-density stratification on counter gradient flux of a homogeneous shear flow

    Energy Technology Data Exchange (ETDEWEB)

    Lida, Oaki; Nagano, Yasutaka [Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya (Japan). Department of Mechanical Engineering

    2007-01-15

    We performed direct numerical simulations of homogeneous shear flow under stable-density stratification to study the buoyancy effects on the heat and momentum transfer. These numerical data were compared with those of a turbulent channel flow to investigate the similarity between the near-wall turbulence and the homogeneous shear flow. We also investigated the generation mechanism of the persistent CGFs (counter gradient fluxes) appearing at the higher wavenumbers of the cospectrum, and lasting over a long time without oscillation. Spatially, the persistent CGFs are associated with the longitudinal vortical structure, which is elongated in the streamwise direction and typically observed in both homogeneous shear flow and near-wall turbulence. The CGFs appear at both the top and bottom of this longitudinal vortical structure, and expand horizontally with an increase in the Richardson number. It was found that the production and turbulent-diffusion terms are responsible for the distribution of the Reynolds shear stress including the persistent CGFs. The buoyancy term, combined with the swirling motion of the vortex, contributes to expand the persistent CGF regions and decrease the down gradient fluxes. (author)

  14. Cross-cultural measurement equivalence of the Revised Conflict Tactics Scales (CTS2 Portuguese version used to identify violence within couples

    Directory of Open Access Journals (Sweden)

    Claudia Leite Moraes

    2002-06-01

    Full Text Available Following a previous evaluation of concept, item and semantic equivalences, this paper assesses the measurement equivalence between a Portuguese version of Revised Conflict Tactics Scales (CTS2 and the original instrument conceived in English. The CTS2 has been widely used to tap violence between couples. An intra-observer reliability evaluation involved 165 replications carried out within a 24-48 hour period. Kappa point-estimates were above 0.75 for all scales except sexual coercion. The analysis of internal consistency concerned 768 subjects with complete sets of items. Kuder-Richardson-20 estimates ranged from 0.65 to 0.86. Results were similar to those found in the original instrument in English for the negotiation, psychological aggression and physical violence scales, yet not so for the sexual coercion and injury scales. Factor analysis identified factors with a recognizable correspondence to the underlying dimensions, although a few inconsistencies were detected. For the assessment of construct validity (n = 528 associations between the instrument's scales were evaluated, as well as the relationships between violence and putative underlying dimensions. Overall, the findings suggest that the version can be used in the Brazilian context, although further investigation should be carried out to unveil some important remaining issues.

  15. TRIUMF the home of Canadian subatomic physics

    CERN Document Server

    Poutissou, J M; Gillies, James D

    2003-01-01

    The acronym for Canada's national laboratory for particle and nuclear physics, TRIUMF, was out of date almost as soon as it was coined. Derived from "TRI-University Meson Facility", it reflected the three universities - British Columbia, Victoria and Simon Fraser that initially conceived the Vancouver laboratory in 1965. Well before the proposal was approved in 1968, however, the University of Alberta had come on board, and today 11 Canadian universities belong to the TRIUMF club. The remainder of the acronym has also become rather misleading, since TRIUMF is now more than a meson facility. The laboratory's current activities include operating the radioactive beam facility, ISAC, and the coordination of Canada's role in the Large Hadron Collider (LHC) project at CERN. The TRIUMF cyclotron was built under the guidance of J Reginald Richardson, who studied under Ernest Lawrence at Berkeley. It produced its first beam in 1974. The cyclotron is literally at the heart of the laboratory, with a meson hall to one si...

  16. Movement disorders

    International Nuclear Information System (INIS)

    Leenders, K.L.

    1986-01-01

    This thesis describes the measurement of brain-tissue functions in patients with movement disorders using positron emission tomography (PET). This scanning technique is a method for direct in vivo quantitation of the regional tissue content of positron emitting radionuclides in brain (or other organs) in an essentially non-invasive way. Ch. 2 outlines some general features of PET and describes the scanner which has been used for the studies in this thesis. Also the tracer methodology, as applied to data investigations of movement disorders, are discussed. Ch. 3 contains the results of the PET investigations which were performed in the study of movement disorders. The results are presented in the form of 12 papers. The main goals of these studies were the understanding of the pathophysiology of Parkinson's disease, Huntington's chorea, Steele-Richardson-Olzewski syndrome and special case reports. Ch. 4 summarizes the results of these publications and Ch. 5 concludes the main part of this thesis with a general discussion of movement disorders in relation to PET investigations. 697 refs.; 60 figs.; 31 tabs

  17. Simulation of mercury capture by sorbent injection using a simplified model.

    Science.gov (United States)

    Zhao, Bingtao; Zhang, Zhongxiao; Jin, Jing; Pan, Wei-Ping

    2009-10-30

    Mercury pollution by fossil fuel combustion or solid waste incineration is becoming the worldwide environmental concern. As an effective control technology, powdered sorbent injection (PSI) has been successfully used for mercury capture from flue gas with advantages of low cost and easy operation. In order to predict the mercury capture efficiency for PSI more conveniently, a simplified model, which is based on the theory of mass transfer, isothermal adsorption and mass balance, is developed in this paper. The comparisons between theoretical results of this model and experimental results by Meserole et al. [F.B. Meserole, R. Chang, T.R. Carrey, J. Machac, C.F.J. Richardson, Modeling mercury removal by sorbent injection, J. Air Waste Manage. Assoc. 49 (1999) 694-704] demonstrate that the simplified model is able to provide good predictive accuracy. Moreover, the effects of key parameters including the mass transfer coefficient, sorbent concentration, sorbent physical property and sorbent adsorption capacity on mercury adsorption efficiency are compared and evaluated. Finally, the sensitive analysis of impact factor indicates that the injected sorbent concentration plays most important role for mercury capture efficiency.

  18. Constructivist Practicies Through Guided Discovery Approach: The Effect on Students' Cognitive Achievements in Nigerian Senior Secondary School Physics

    Directory of Open Access Journals (Sweden)

    A.O. Akinbobola

    2009-12-01

    Full Text Available The study investigated constructivist practices through guided discovery approach and the effect on students’ cognitive achievement in Nigerian senior secondary school Physics. The study adopted pretest-posttest control group design. A criterion sampling technique was used to select six schools out of nine schools that met the criteria. A total of 278 students took part in the study; this was made up of 141 male students and 137 female students in their respective intact classes. Physic Achievement Test (PAT with the internal consistency of 0.77 using Kuder-Richardson formula (21 was the instrument used in collecting data. The data were analyzed using Analysis of Covariance (ANCOVA and t-test. The results showed that guided discovery approaches was the most effective in facilitating students’ achievement in physics after being taught using a pictorial organizer. This was followed by demonstration while expository was found to be the least effective. Also, there exists no significant difference in the achievement of male and female physics students taught with guided discovery, demonstration and expository teaching approaches and corresponding exposure to a pictorial organizer. It is recommended that physics teachers should endeavor to use constructivist practices through guided discovery approach in order to engage students in problem solving activities, independent learning, critical thinking and understanding, and creative learning, rather than in rote learning and memorization.

  19. Structure analysis of low velocity reactive flows on a flat plate: the case of the laminar diffusion flame in a low gravity environment; Analyse de la structure des ecoulements reactifs a faible vitesse sur une plaque plane: cas de la flamme de diffusion laminaire sous un environnement de gravite reduite

    Energy Technology Data Exchange (ETDEWEB)

    Joulain, P.

    2003-09-01

    The combustion of a flat plate in a boundary layer under microgravity conditions, which was first described by Emmons, is studied using a gaseous burner. Magnitude of injection and blowing velocities are chosen to be characteristic of pyrolyzing velocity of solid fuels and of ventilation systems in space stations. These velocities are about 10 cm/s for oxidizer flow and 0.4 cm/s for fuel flow. In this configuration, flame layout results from a coupled interaction between oxidizer flow, fuel flow and thermal expansion. Influences of these parameters are studied by means of flame length and standoff distance measurements using CH* chemiluminescence's and visible emission of the flame. Flow was also studied with Particle Image Velocimetry (PIV). At first with inert flows, with and without injection to identify burner effects on it, and then with a reacting flow in a microgravity environment. Thermal expansion effects have been shown by means of the acceleration of oxidizer flow. Three dimensional effects, which are strongly marked for high injection velocities did not were studied, but three dimensional tools adaptability (wavelength and polarizing coding laser tomography) to parabolic flights particular conditions were investigate. Flame sensitivity to g-jitters was studied using a local modified Richardson number introduced by Torero and g-jitters effect on flame were investigated according to g-jitters frequency and range involved by parabolic flights. (author)

  20. Observations of the upper ocean response to storm forcing in the South Atlantic Roaring Forties

    Directory of Open Access Journals (Sweden)

    R. Marsh

    1995-10-01

    Full Text Available In the austral summer of 1992–1993 the passage of a storm system drove a strong upper ocean response at 45°S in the mid-South Atlantic. Good in situ observations were obtained. CTD casts revealed that the mixed layer deepened by ~40 m over 4 days. Wind stirring dominated over buoyancy flux-driven mixing during the onset of high winds. Doppler shear currents further reveal this to be intimately related to inertial dynamics. The penetration depth of inertial currents, which are confined to the mixed layer, increases with time after a wind event, matched by a downward propagation of low values of the Richardson number. This suggests that inertial current shear is instrumental in producing turbulence at the base of the mixed layer. Evolution of inertial transport is simulated using a time series of ship-observed wind stress. Simulated transport is only 30–50% of the observed transport, suggesting that much of the observed inertial motion was forced by an earlier (possibly remote storm. Close proximity of the subtropical front further complicates the upper ocean response to the storm. A simple heat balance for the upper 100 m reveals that surface cooling and mixing (during the storm can account for only a small fraction of an apparent ~1 °C mixed layer cooling.

  1. Life Span and Resiliency Theory: A Critical Review

    Directory of Open Access Journals (Sweden)

    Alexa Smith-Osborne

    2007-05-01

    Full Text Available Theories of life span development describe human growth and change over the life cycle (Robbins, Chatterjee, & Canda, 2006. Major types of developmental theories include biological, psychodynamic, behavioral, and social learning, cognitive, moral, and spiritual, and those influenced by systems, empowerment, and conflict theory. Life span development theories commonly focus on ontogenesis and sequential mastery of skills, tasks, and abilities. Social work scholars have pointed out that a limitation of life span and other developmental theory is lack of attention to resilience (Greene, 2007; Robbins et al., 1998. The concept of resilience was developed to “describe relative resistance to psychosocial risk experiences” (Rutter, 1999b, p. 119. Longitudinal studies focused on typical and atypical child development informed theory formulation in developmental psychopathology (Garmezy & Rutter, 1983; Luthar, Cichetti,& Becker, 2000 and in an evolving resilience model (Richardson, 2002; Werner & Smith, 1992. Research on resilience has found a positive relationship between a number of individual traits and contextual variables and resistance to a variety of risk factors among children and adolescents. More recently, resilience research has examined the operation of these same factors in the young adult, middle-age, and elder life stages. This article examines the historical and conceptual progression of the two developmental theories—life span and resiliency—and discusses their application to social work practice and education in human behavior in the social environment.

  2. Use of naturally occurring mercury to determine the importance of cutthroat trout to Yellowstone grizzly bears

    Science.gov (United States)

    Felicetti, L.A.; Schwartz, C.C.; Rye, R.O.; Gunther, K.A.; Crock, J.G.; Haroldson, M.A.; Waits, L.; Robbins, C.T.

    2004-01-01

    Spawning cutthroat trout (Oncorhynchus clarki (Richardson, 1836)) are a potentially important food resource for grizzly bears (Ursus arctos horribilis Ord, 1815) in the Greater Yellowstone Ecosystem. We developed a method to estimate the amount of cutthroat trout ingested by grizzly bears living in the Yellowstone Lake area. The method utilized (i) the relatively high, naturally occurring concentration of mercury in Yellowstone Lake cutthroat trout (508 ± 93 ppb) and its virtual absence in all other bear foods (6 ppb), (ii) hair snares to remotely collect hair from bears visiting spawning cutthroat trout streams between 1997 and 2000, (iii) DNA analyses to identify the individual and sex of grizzly bears leaving a hair sample, (iv) feeding trials with captive bears to develop relationships between fish and mercury intake and hair mercury concentrations, and (v) mercury analyses of hair collected from wild bears to estimate the amount of trout consumed by each bear. Male grizzly bears consumed an average of 5 times more trout/kg bear than did female grizzly bears. Estimated cutthroat trout intake per year by the grizzly bear population was only a small fraction of that estimated by previous investigators, and males consumed 92% of all trout ingested by grizzly bears.

  3. Characterization of sputter deposited thin film scandate cathodes for miniaturized thermionic converter applications

    Science.gov (United States)

    Zavadil, Kevin R.; Ruffner, Judith H.; King, Donald B.

    1999-01-01

    We have successfully developed a method for fabricating scandate-based thermionic emitters in thin film form. The primary goal of our effort is to develop thin film emitters that exhibit low work function, high intrinsic electron emissivity, minimum thermal activation properties and that can be readily incorporated into a microgap converter. Our approach has been to incorporate BaSrO into a Sc2O3 matrix using rf sputtering to produce thin films. Diode testing has shown the resulting films to be electron emissive at temperatures as low as 900 K with current densities of 0.1 mA.cm-2 at 1100 K and saturation voltages. We calculate an approximate maximum work function of 1.8 eV and an apparent emission constant (Richardson's constant, A*) of 36 mA.cm-2.K-2. Film compositional and structural analysis shows that a significant surface and subsurface alkaline earth hydroxide phase can form and probably explains the limited utilization and stability of Ba and its surface complexes. The flexibility inherent in sputter deposition suggests alternate strategies for eliminating undesirable phases and optimizing thin film emitter properties.

  4. Computation of aerodynamic interference effects on oscillating airfoils with controls in ventilated subsonic wind tunnels

    Science.gov (United States)

    Fromme, J. A.; Golberg, M. A.

    1979-01-01

    Lift interference effects are discussed based on Bland's (1968) integral equation. A mathematical existence theory is utilized for which convergence of the numerical method has been proved for general (square-integrable) downwashes. Airloads are computed using orthogonal airfoil polynomial pairs in conjunction with a collocation method which is numerically equivalent to Galerkin's method and complex least squares. Convergence exhibits exponentially decreasing error with the number n of collocation points for smooth downwashes, whereas errors are proportional to 1/n for discontinuous downwashes. The latter can be reduced to 1/n to the m+1 power with mth-order Richardson extrapolation (by using m = 2, hundredfold error reductions were obtained with only a 13% increase of computer time). Numerical results are presented showing acoustic resonance, as well as the effect of Mach number, ventilation, height-to-chord ratio, and mode shape on wind-tunnel interference. Excellent agreement with experiment is obtained in steady flow, and good agreement is obtained for unsteady flow.

  5. Validation of the Italian version of the Yale Food Addiction Scale 2.0 (I-YFAS 2.0) in a sample of undergraduate students.

    Science.gov (United States)

    Aloi, Matteo; Rania, Marianna; Rodríguez Muñoz, Rita Cristina; Jiménez Murcia, Susana; Fernández-Aranda, Fernando; De Fazio, Pasquale; Segura-Garcia, Cristina

    2017-09-01

    Food addiction (FA) refers to a condition characterized by addiction in relation to some high-fat and high-sugar carbohydrate that leads to clinically significant impairment or distress on several areas of functioning. The Yale Food Addiction Scale 2.0 (YFAS 2.0) has been recently updated to measure FA according to the DSM-5 criteria for substance-related and addictive disorders. This study aimed at validating the Italian version of YFAS 2.0. A sample of 574 Italian university students was involved in this research. Confirmatory Factor Analysis (CFA) and Kuder-Richardson's alpha for dichotomous data were run to evaluate scale structure and reliability. Correlations between YFAS 2.0 and eating psychopathology, binge eating, sleep, and mood symptoms were evaluated. Analogously to the original version, a single factor structure emerged at the CFA. The alpha coefficient was 0.87. Moreover, sound, from moderate to high, correlations were found with other measures. The Italian version of the YFAS 2.0 has demonstrated in a sample of university students to be a useful tool to investigate food addictions. Level of evidence Level V, descriptive study.

  6. Evolutionary cell biology: functional insight from "endless forms most beautiful".

    Science.gov (United States)

    Richardson, Elisabeth; Zerr, Kelly; Tsaousis, Anastasios; Dorrell, Richard G; Dacks, Joel B

    2015-12-15

    In animal and fungal model organisms, the complexities of cell biology have been analyzed in exquisite detail and much is known about how these organisms function at the cellular level. However, the model organisms cell biologists generally use include only a tiny fraction of the true diversity of eukaryotic cellular forms. The divergent cellular processes observed in these more distant lineages are still largely unknown in the general scientific community. Despite the relative obscurity of these organisms, comparative studies of them across eukaryotic diversity have had profound implications for our understanding of fundamental cell biology in all species and have revealed the evolution and origins of previously observed cellular processes. In this Perspective, we will discuss the complexity of cell biology found across the eukaryotic tree, and three specific examples of where studies of divergent cell biology have altered our understanding of key functional aspects of mitochondria, plastids, and membrane trafficking. © 2015 Richardson et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  7. On the Spatial Distribution of High Velocity Al-26 Near the Galactic Center

    Science.gov (United States)

    Sturner, Steven J.

    2000-01-01

    We present results of simulations of the distribution of 1809 keV radiation from the decay of Al-26 in the Galaxy. Recent observations of this emission line using the Gamma Ray Imaging Spectrometer (GRIS) have indicated that the bulk of the AL-26 must have a velocity of approx. 500 km/ s. We have previously shown that a velocity this large could be maintained over the 10(exp 6) year lifetime of the Al-26 if it is trapped in dust grains that are reaccelerated periodically in the ISM. Here we investigate whether a dust grain velocity of approx. 500 km/ s will produce a distribution of 1809 keV emission in latitude that is consistent with the narrow distribution seen by COMPTEL. We find that dust grain velocities in the range 275 - 1000 km/ s are able to reproduce the COMPTEL 1809 keV emission maps reconstructed using the Richardson-Lucy and Maximum Entropy image reconstruction methods while the emission map reconstructed using the Multiresolution Regularized Expectation Maximization algorithm is not well fit by any of our models. The Al-26 production rate that is needed to reproduce the observed 1809 keV intensity yields in a Galactic mass of Al-26 of approx. 1.5 - 2 solar mass which is in good agreement with both other observations and theoretical production rates.

  8. Time-dependent mixed convection heat transfer from a sphere in a micro-gravity environment

    International Nuclear Information System (INIS)

    Hommel, M.J.

    1987-01-01

    A fundamental problem of interest for crystal growth in micro-gravity applications involves the mixed convection heat transfer from a sphere in a uniform flow of fluid at a differing temperature. Under the combined influence of the imposed free stream as well as an induced buoyancy force due to thermal expansion of the fluid, the heat transfer from the sphere will be different from that of either the pure forced convection flow or the pure free convection flow. For the present study, the method of matched asymptotic expansions is applied to the laminar flow problem of an impulsively heated, impulsively started sphere in an originally quiescent fluid. Time series expansions are developed for the dependent variables by acknowledging the existence of two district regions: one, an inner region, near the sphere, in which viscous effects are significant; and two, an outer region in which the fluid may be treated as inviscid. The time series expansions are developed in terms of the Reynolds number and Richardson number (Buoyancy Parameter), and the relevant heat transfer and drag coefficients are calculated and plotted

  9. Combined effects of magnetic field and partial slip on obliquely striking rheological fluid over a stretching surface

    International Nuclear Information System (INIS)

    Nadeem, S.; Mehmood, Rashid; Akbar, Noreen Sher

    2015-01-01

    This study explores the collective effects of partial slip and transverse magnetic field on an oblique stagnation point flow of a rheological fluid. The prevailing momentum equations are designed by manipulating Casson fluid model. By applying the suitable similarity transformations, the governing system of equations is being transformed into coupled nonlinear ordinary differential equations. The resulting system is handled numerically through midpoint integration scheme together with Richardson's extrapolation. It is found that both normal and tangential velocity profiles decreases with an increase in magnetic field as well as slip parameter. Streamlines pattern are presented to study the actual impact of slip mechanism and magnetic field on the oblique flow. A suitable comparison with the previous literature is also provided to confirm the accuracy of present results for the limiting case. - Highlights: • The MHD 2-Dimensional flow of Casson fluid is present. • Streamlines pattern are presented to study the actual impact of slip mechanism and magnetic field on the oblique flow. • The prevailing momentum equations are designed by manipulating Casson fluid model. • Obtained coupled ordinary differential equations are investigated numerically. • Graphical results are obtained for each physical parameter

  10. The U.S. wind market is back

    International Nuclear Information System (INIS)

    Azua, C.R. de

    2000-01-01

    The recent growth in wind energy projects in the US was spurred by supportive policies in a few states, steadily improving economics, the federal wind energy Production Tax Credit and emerging green power programs. Wind farms are springing up around the US, providing clean energy as well as an economic boon to farmers and local communities. This year's headlines announced the rebirth of the US wind energy market, as wind farms were dedicated in local communities from coast to coast. At this year's exuberant pace of development, utility-scale wind energy seems well on its way to generating 5% of the nation's electricity by 2020, the target set by the Administration and announced by Energy Secretary Bill Richardson at the wind industry's annual conference earlier this year. Wind energy projects have mushroomed throughout the country, most notably in the Midwest. In the eighteen months from July 1998 to December 1999, the American Wind Energy Association (AWEA) estimates that wind energy companies will have added almost 900 megawatts (MW) to the nation's generating capacity. At the same time, new, more efficient turbines replaced some 200 MW of aging equipment. In all, 1,096 MW of new wind generators were installed over that period, representing an investment of well over $1.1 billion and bringing American utility-scale generating capacity to over 2,500 MW

  11. DE-BLURRING SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY IMAGES USING WAVELET DECOMPOSITION

    Directory of Open Access Journals (Sweden)

    Neethu M. Sasi

    2016-02-01

    Full Text Available Single photon emission computed tomography imaging is a popular nuclear medicine imaging technique which generates images by detecting radiations emitted by radioactive isotopes injected in the human body. Scattering of these emitted radiations introduces blur in this type of images. This paper proposes an image processing technique to enhance cardiac single photon emission computed tomography images by reducing the blur in the image. The algorithm works in two main stages. In the first stage a maximum likelihood estimate of the point spread function and the true image is obtained. In the second stage Lucy Richardson algorithm is applied on the selected wavelet coefficients of the true image estimate. The significant contribution of this paper is that processing of images is done in the wavelet domain. Pre-filtering is also done as a sub stage to avoid unwanted ringing effects. Real cardiac images are used for the quantitative and qualitative evaluations of the algorithm. Blur metric, peak signal to noise ratio and Tenengrad criterion are used as quantitative measures. Comparison against other existing de-blurring algorithms is also done. The simulation results indicate that the proposed method effectively reduces blur present in the image.

  12. Improving Drinking Water Quality by Remineralisation.

    Science.gov (United States)

    Luptáková, Anna; Derco, Ján

    2015-01-01

    The reason of low mineral content in source water is its origin in poorly soluble mineral geological structures. There are many areas with very soft low-mineralised water around the world. All people involved in drinking water treatment as well as some public health experts and producers of chemicals used for water treatment may be interested in the study. Enrichment of drinking water by minerals including calcium and magnesium is very important particularly in regions where drinking water is prepared by desalination. The aim of this work was to study and intensify the recarbonization process. Half-calcined dolomite in combination with carbon dioxide constitutes the chemistry of the applied method. Advantages of using a fluidised bed reactor contributed also significantly to the process efficiency enhancement. Continuous input of carbon dioxide into the fluidised bed recarbonization reactor resulted in an increase in the recarbonization rate by about one order of magnitude compared with the process in without carbon dioxide addition. Very good fit of experimental data for hydrodynamic characteristics of fluidised bed was obtained using simple model based on the Richardson and Zaki expansion equation. The first order model describes kinetic data from the recarbonization process with a good accuracy. Higher recarbonization rates were observed with smaller particles of half-calcined dolomite.

  13. Large-Eddy Simulation of Flow and Pollutant Transport in Urban Street Canyons with Ground Heating

    Science.gov (United States)

    Li, Xian-Xiang; Britter, Rex E.; Koh, Tieh Yong; Norford, Leslie K.; Liu, Chun-Ho; Entekhabi, Dara; Leung, Dennis Y. C.

    2010-11-01

    Our study employed large-eddy simulation (LES) based on a one-equation subgrid-scale model to investigate the flow field and pollutant dispersion characteristics inside urban street canyons. Unstable thermal stratification was produced by heating the ground of the street canyon. Using the Boussinesq approximation, thermal buoyancy forces were taken into account in both the Navier-Stokes equations and the transport equation for subgrid-scale turbulent kinetic energy (TKE). The LESs were validated against experimental data obtained in wind-tunnel studies before the model was applied to study the detailed turbulence, temperature, and pollutant dispersion characteristics in the street canyon of aspect ratio 1. The effects of different Richardson numbers ( Ri) were investigated. The ground heating significantly enhanced mean flow, turbulence, and pollutant flux inside the street canyon, but weakened the shear at the roof level. The mean flow was observed to be no longer isolated from the free stream and fresh air could be entrained into the street canyon at the roof-level leeward corner. Weighed against higher temperature, the ground heating facilitated pollutant removal from the street canyon.

  14. A numerical study of diurnally varying surface temperature on flow patterns and pollutant dispersion in street canyons

    Science.gov (United States)

    Tan, Zijing; Dong, Jingliang; Xiao, Yimin; Tu, Jiyuan

    2015-03-01

    The impacts of the diurnal variation of surface temperature on street canyon flow pattern and pollutant dispersion are investigated based on a two-dimensional street canyon model under different thermal stratifications. Uneven distributed street temperature conditions and a user-defined wall function representing the heat transfer between the air and the street canyon are integrated into the current numerical model. The prediction accuracy of this model is successfully validated against a published wind tunnel experiment. Then, a series of numerical simulations representing four time scenarios (Morning, Afternoon, Noon and Night) are performed at different Bulk Richardson number (Rb). The results demonstrate that uneven distributed street temperature conditions significantly alters street canyon flow structure and pollutant dispersion characteristics compared with conventional uniform street temperature assumption, especially for the morning event. Moreover, air flow patterns and pollutant dispersion are greatly influenced by diurnal variation of surface temperature under unstable stratification conditions. Furthermore, the residual pollutant in near-ground-zone decreases as Rb increases in noon, afternoon and night events under all studied stability conditions.

  15. Influence of climate change on the flowering of temperate fruit trees

    Science.gov (United States)

    Perez-Lopez, D.; Ruiz-Ramos, M.; Sánchez-Sánchez, E.; Centeno, A.; Prieto-Egido, I.; Lopez-de-la-Franca, N.

    2012-04-01

    It is well known that winter chilling is necessary for the flowering of temperate trees. The chilling requirement is a criterion for choosing a species or variety at a given location. Also chemistry products can be used for reducing the chilling-hours needs but make our production more expensive. This study first analysed the observed values of chilling hours for some representative agricultural locations in Spain for the last three decades and their projected changes under climate change scenarios. Usually the chilling is measured and calculated as chilling-hours, and different methods have been used to calculate them (e.g. Richarson et al., 1974 among others) according to the species considered. For our objective North Carolina method (Shaltout and Unrath, 1983) was applied for apples, Utah method (Richardson et al. 1974) for peach and grapevine and the approach used by De Melo-Abreu et al. (2004) for olive trees. The influence of climate change in temperate trees was studied by calculating projections of chilling-hours with climate data from Regional Climate Models (RCMs) at high resolution (25 km) from the European Project ENSEMBLES (http://www.ensembles-eu.org/). These projections will allow for analysing the modelled variations of chill-hours between 2nd half of 20C and 1st half of 21C at the study locations.

  16. Entrainment at a sediment concentration interface in turbulent channel flow

    Science.gov (United States)

    Salinas, Jorge; Shringarpure, Mrugesh; Cantero, Mariano; Balachandar, S.

    2016-11-01

    In this work we address the role of turbulence on entrainment at a sediment concentration interface. This process can be conceived as the entrainment of sediment-free fluid into the bottom sediment-laden flow, or alternatively, as the entrainment of sediment into the top sediment-free flow. We have performed direct numerical simulations for fixed Reynolds and Schmidt numbers while varying the values of Richardson number and particle settling velocity. The analysis performed shows that the ability of the flow to pick up a given sediment size decreases with the distance from the bottom, and thus only fine enough sediment particles are entrained across the sediment concentration interface. For these cases, the concentration profiles evolve to a final steady state in good agreement with the well-known Rouse profile. The approach towards the Rouse profile happens through a transient self-similar state. Detailed analysis of the three dimensional structure of the sediment concentration interface shows the mechanisms by which sediment particles are lifted up by tongues of sediment-laden fluid with positive correlation between vertical velocity and sediment concentration. Finally, the mixing ability of the flow is addressed by monitoring the center of mass of the sediment-laden layer. With the support of ExxonMobil, NSF, ANPCyT, CONICET.

  17. Effect of inhomogeneous Schottky barrier height of SnO2 nanowires device

    Science.gov (United States)

    Amorim, Cleber A.; Bernardo, Eric P.; Leite, Edson R.; Chiquito, Adenilson J.

    2018-05-01

    The current–voltage (I–V) characteristics of metal–semiconductor junction (Au–Ni/SnO2/Au–Ni) Schottky barrier in SnO2 nanowires were investigated over a wide temperature range. By using the Schottky–Mott model, the zero bias barrier height Φ B was estimated from I–V characteristics, and it was found to increase with increasing temperature; on the other hand the ideality factor (n) was found to decrease with increasing temperature. The variation in the Schottky barrier and n was attributed to the spatial inhomogeneity of the Schottky barrier height. The experimental I–V characteristics exhibited a Gaussian distribution having mean barrier heights {\\overline{{{Φ }}}}B of 0.30 eV and standard deviation σ s of 60 meV. Additionally, the Richardson modified constant was obtained to be 70 A cm‑2 K‑2, leading to an effective mass of 0.58m 0. Consequently, the temperature dependence of I–V characteristics of the SnO2 nanowire devices can be successfully explained on the Schottky–Mott theory framework taking into account a Gaussian distribution of barrier heights.

  18. The TKE dissipation rate in the northern South China Sea

    Science.gov (United States)

    Lozovatsky, Iossif; Liu, Zhiyu; Fernando, Harindra Joseph S.; Hu, Jianyu; Wei, Hao

    2013-12-01

    The microstructure measurements taken during the summer seasons of 2009 and 2010 in the northern South China Sea (between 18°N and 22.5°N, and from the Luzon Strait to the eastern shelf of China) were used to estimate the averaged dissipation rate in the upper pycnocline of the deep basin and on the shelf. Linear correlation between and the estimates of available potential energy of internal waves, which was found for this data set, indicates an impact of energetic internal waves on spatial structure and temporal variability of . On the shelf stations, the bottom boundary layer depth-integrated dissipation reaches 17-19 mW/m2, dominating the dissipation in the water column below the surface layer. In the pycnocline, the integrated dissipation was mostly ˜10-30 % of . A weak dependence of bin-averaged dissipation on the Richardson number was noted, according to , where ɛ 0 + ɛ m is the background value of for weak stratification and Ri cr = 0.25, pointing to the combined effects of shear instability of small-scale motions and the influence of larger-scale low frequency internal waves. The latter broadly agrees with the MacKinnon-Gregg scaling for internal-wave-induced turbulence dissipation.

  19. Correlation between the Histo-Pathological Grade and Tumour Uptake Analysis of Tc99m-MIBI in Breast Cancer Nodules

    International Nuclear Information System (INIS)

    Haider, Saima

    2006-01-01

    Full text: Breast Cancer is the most common malignancy among women in the world. X-Ray mammography is the best screening device, but radionuclide imaging such as Tc-99m MIBI Scintimammography promises to play an important role as an adjunctive functional imaging tool in breast malignancies. The aim of the study was to correlate the Histopathological grade and semi-quantitative analysis of tracer uptake in Tc-99m MIBI Scintimammography. Seven (7) female patients (mean age 47.5+10) with locally advanced breast cancer were imaged. Informed written consent was taken from each patient. Average of 950 MBq (0.3 mCi/kg) Tc-99m MIBI was injected intravenously in the contra lateral arm to the site of lesion. Static prone MIBI Scintimammoscans of the affected side was acquired 5-10 minutes post injection for 10 minutes. Similarly 10 minute static view of normal side was also done. The background subtracted lesions to normal ratios (LNR) were acquired. Histopathological grading of tumours was done according to Bloom Richardson grading system. All the tumours were infiltrating ductal carcinoma. The mean LNR value is higher in high-grade lesions while less in low-grade tumours. Higher un-differentiation of malignant tumour is related with aggressive nature of the disease. This would suggest that more aggressive tumours have higher uptake of Tc-99m MIBI and therefore greater invasiveness of malignancy. (author)

  20. Investigation of temperature fluctuation phenomena in a stratified steam-water two-phase flow in a simulating pressurizer spray pipe of a pressurized water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Miyoshi, Koji, E-mail: miyoshi.koj@inss.co.jp; Takenaka, Nobuyuki; Ishida, Taisuke; Sugimoto, Katsumi

    2017-05-15

    Highlights: • Thermal hydraulics phenomena were discussed in a spray pipe of pressurizer. • Temperature fluctuation was investigated in a stratified steam-water two-phase. • Remarkable liquid temperature fluctuations were observed in the liquid layer. • The observed temperature fluctuations were caused by the internal gravity wave. • The temperature fluctuations decreased with increasing dissolved oxygen. - Abstract: Temperature fluctuation phenomena in a stratified steam-water two-phase flow in a horizontal rectangular duct, which simulate a pressurizer spray pipe of a pressurized water reactor, were studied experimentally. Vertical distributions of the temperature and the liquid velocity were measured with water of various dissolved oxygen concentrations. Large liquid temperature fluctuations were observed when the water was deaerated well and dissolved oxygen concentration was around 10 ppb. The large temperature fluctuations were not observed when the oxygen concentration was higher. It was shown that the observed temperature fluctuations were caused by the internal gravity wave since the Richardson numbers were larger than 0.25 and the temperature fluctuation frequencies were around the Brunt-Väisälä frequencies in the present experimental conditions. The temperature fluctuations decreased by the non-condensable gas since the non-condensable gas suppressed the condensation and the temperature difference in the liquid layer was small.